Evaluation of the absorption line blackbody distribution function of CO2 and H2O using the proper orthogonal decomposition and hyperbolic correlations - Liu, F.; Chu, H.; Zhou, H.; Smallwood, G. J. (Journal of Quantitative Spectroscopy and Radiative Transfer, 2013)
Databases of the absorption line blackbody distribution function (ALBDF) of CO2 and H2O were generated over a wide range of gas and blackbody temperatures and the full range of gas concentration from line-by-line (LBL) calculations using the latest version of HITEMP. Proper orthogonal decomposition (POD) and the hyperbolic correlations (HC) were then used for rapid calculation the ALBDF value at an arbitrary combination of gas and blackbody temperatures and gas concentration. A novel hyperbolic correlation for H2O was proposed to fully account for the self-broadening effect. The accuracy of POD and the HC was evaluated by comparing the ALBDF values and the total gas emissivities from these two approximate methods at several selected conditions against those from LBL calculations. POD is significantly more accurate than HC at essentially no extra computational costs.
Keywords: Line-by-line; Spectral line based weight-sum-of-grey-gases model; Absorption line blackbody function; Proper orthogonal decomposition; Hyperbolic correlation

Gap tolerance allowance and robotic operational window for friction stir butt welding of AA6061 - Wanjara, P.; Monsarrat, B.; Larose, S. (Journal of Materials Processing Technology, 2013)
In this work, it was determined that with increasing weld pitch, the occurrence of a “lazy S” defect in the weld nugget of friction stir welded (FSWed) AA6061 became increasingly pronounced, though its impact on the bend performance of the weld was negligible. For a fixed weld pitch of 0.48, the effect of gap, i.e. the spacing between two sheets at the butt joint interface, on the joint quality of AA6061 was evaluated in terms of the welding defects, microstructure, hardness and bend performance. Fully penetrated welds without metallurgical defects such as wormholes were obtained up to a joint gap of 0.5 mm. Though the overall microhardness and bend performance of the welds remained unaffected until a joint gap of 0.8 mm, the decrease in the forge force during FSW beyond a joint gap value of 0.5 mm may represent a more critical limit in regards to the industrial application of the process; this is especially important when applying force control during processing to ensure a constant shoulder penetration in the material for addressing practical considerations, such as thickness variations in the assembly, clamping distortions and tool wear. Based on these results and using force amplitudes recorded during the welding experiments, a robotic scenario was synthesized with an appropriate operational window for continuous-path friction stir butt welding (FSBW) of 3.18-mm-thick sheets clamped to a 1 m × 1 m horizontal welding table. An appropriate industrial robot model was selected and the associated geometric workcell layout was developed for this application. This scenario was implemented in a physical prototype and used to successfully produce 1-m-long FSWed assemblies that exhibited good tensile mechanical performance.
Keywords: Friction stir welding; AA6061-T6; Gap tolerance; Operational window; Kinetostatic analysis; Industrial robot

Comparison of three Co-C fixed points constructed using different crucible lining materials - Todd, A. D. W.; Woods, D. J. (Temperature : its measurement and control in science and industry, volume 8: Proceedings of the Ninth International Temperature Symposium, 2013)
The melting plateaus of three Co-C fixed points for radiation thermometry with different constructions were measured and compared. Two of the fixed points were of the hybrid type and contained either carbon composite cloth or pyrolytic graphite sheet between the graphite sleeve and the crucible wall. The third fixed point contained only the graphite sleeve. Little difference was found in the shapes of the melting curves between the fixed points. Given a comparison uncertainty of 37 mK (k = 1), there were, however, significant differences in the melting temperatures determined for each of the fixed points. Over three days of measurement, the melting temperature of the fixed point filled using the pyrolytic sheet drifted up by nearly 140 mK.
Keywords: high temperature fixed points; radiation thermometry; Co-C

Solid-state 17O NMR of pharmaceutical compounds : salicylic acid and aspirin - Kong, Xianqi; Shan, Melissa; Terskikh, Victor; Hung, Ivan; Gan, Zhehong; Wu, Gang (The Journal of Physical Chemistry B, 2013)
We report solid-state NMR characterization of the 17O quadrupole coupling (QC) and chemical shift (CS) tensors in five site-specifically 17O-labeled samples of salicylic acid and o-acetylsalicylic acid (Aspirin). High-quality 17O NMR spectra were obtained for these important pharmaceutical compounds under both static and magic angle spinning (MAS) conditions at two magnetic fields, 14.0 and 21.1 T. A total of 14 17O QC and CS tensors were experimentally determined for the seven oxygen sites in salicylic acid and Aspirin. Although both salicylic acid and Aspirin form hydrogen bonded cyclic dimers in the solid state, we found that the potential curves for the concerted double proton transfer in these two compounds are significantly different. In particular, while the double-well potential curve in Aspirin is nearly symmetrical, it is highly asymmetrical in salicylic acid. This difference results in quite different temperature dependencies in 17O MAS spectra of the two compounds. A careful analysis of variabletemperature 17O MAS NMR spectra of Aspirin allowed us to obtain the energy asymmetry (ΔE) of the double-well potential, ΔE = 3.0 ± 0.5 kJ/mol. We were also able to determine a lower limit of ΔE for salicylic acid, ΔE > 10 kJ/mol. These asymmetrical features in potential energy curves were confirmed by plane-wave DFT computations, which yielded ΔE = 3.7 and 17.8 kJ/mol for Aspirin and salicylic acid, respectively. To complement the solid-state 17O NMR data, we also obtained solid-state 1H and 13C NMR spectra for salicylic acid and Aspirin. Using experimental NMR parameters obtained for all magnetic nuclei present in salicylic acid and Aspirin, we found that plane-wave DFT computations can produce highly accurate NMR parameters in welldefined crystalline organic compounds.

Immersed boundary finite elements for 3D flow simulations in twin-screw extruders - Hétu, J.-F.; Ilinca, F. (Computers & Fluids, 2013)
This paper presents applications of a recently proposed Immersed Boundary (IB) method to the solution of the flow around moving and complex shaped surfaces, in particular inside twin-screw extruders. Solving the flow around rotating screw elements implies significant changes in the computational topology at every time step. Using multiple meshes or adaptive methods to tackle these would require extensive meshing and interpolation work that has to be repeated each time step. Mesh generation and solution interpolation between successive grids may be costly and may introduce errors if the geometry changes significantly during the course of the computation. These drawbacks are avoided when the solution algorithm can tackle grids that do not fit the shape of immersed objects. In this work a fixed mesh is used covering both the fluid and solid regions, and the boundary of immersed objects is defined using a time dependent level-set function. The Body Conformal Enrichment (BCE) method is used to accurately impose boundary conditions on the surface of immersed bodies. The proposed algorithm enriches the finite element discretization of interface elements with additional degrees of freedom, the latter being eliminated at element level. Numerical applications are shown in which the flow inside twin-screw extruders is computed for multiple screw elements. A generalized non-Newtonian fluid is used to model molten polymer. Solutions will be shown for various rotation velocities of the screw as the viscosity depends on the shear rate.
Keywords: Immersed boundary method; Twin-screw extruders; Finite elements; Non-body-conformal mesh; Body conformal enrichment

Calcium supplementation increases circulating cholesterol by reducing its catabolism via GPER and TRPC1-dependent pathway in estrogen deficient women - Li, Songtao; Li, Ying; Ning, Hua; Na, Lixin; Niu, Yucun; Wang, Maoqing; Feng, Rennan; Liu, Liyan; Guo, Fuchuan; Hou, Shaoying; Chu, Xia; Wang, Yemei; et al. (International Journal of Cardiology, 2013)
Background: Limited studies have addressed the effects of calcium supplementation (CaS) on serum total cholesterol (TC) in postmenopausal women and the results are inconclusive. Moreover, the potential mechanisms through which CaS regulates cholesterol metabolism in the absence of estrogen are still sealed for the limitation of human being study. Methods: Cross-sectional survey, animal and in vitro experiments were conducted to investigate the effect of CaS on endogenous cholesterol metabolism in estrogen deﬁciency and identify its potential mechanisms. Ovariectomized rats were used to mimic estrogen deﬁciency. In vitro, HepG2 cell line was exposed to estradiol and/or calcium treatment. Results: We demonstrated that CaS signiﬁcantly increased serum TC and the risk of hypercholesterolemia and myocardial infarction in postmenopausal women. Increased serum TC in estrogen deﬁciency was caused mainly by decreased cholesterol catabolism rather than increased synthesis. This was mediated by reduced 7α-hydroxylase resulting from increased liver intracellular Ca²⁺ concentrations, reduced intracellular basal cAMP and subsequent up-regulation of SREBP-1c and SHP expression. Estrogen had a protective role in preventing CaS-induced TC increase by activating the G-protein coupled estrogen receptor, which mediated the estrogen effect through the transient receptor potential canonical 1 cation channel. Conclusions: CaS increases endogenous serum TC via decreasing hepatic cholesterol catabolism in estrogen deﬁciency. G-protein coupled estrogen receptor is shown to be a key target in mediating CaS-induced TC increase. CaS should be monitored for the prevention of serum TC increase during menopause.
Keywords: Calcium supplementation; Cholesterol; Estrogen; G-Protein coupled estrogen receptor

Synthesis and evaluation of L-Rhamnose 1C-Phosphonates as nucleotidylyltransferase inhibitors - Loranger, Matthew W.; Forget, Stephanie M.; Mccormick, Nicole E.; Syvitski, Raymond T.; Jakeman, David L. (The Journal of Organic Chemistry, 2013)
We report the synthesis of a series of phosphonates and ketosephosphonates possessing an l-rhamnose scaffold with varying degrees of fluorination. These compounds were evaluated as potential inhibitors of α-d-glucose 1-phosphate thymidylyltransferase (Cps2L), the first enzyme in Streptococcus pneumoniae l-rhamnose biosynthesis, and a novel antibiotic target. Enzyme–substrate and enzyme–inhibitor binding experiments were performed using water-ligand observed binding via gradient spectroscopy (WaterLOGSY) NMR for known sugar nucleotide substrates and selected phosphonate analogues. IC50 values were measured and Ki values were calculated for inhibitors. New insights were gained into the binding promiscuity of enzymes within the prokaryotic l-rhamnose biosynthetic pathway (Cps2L, RmlB–D) and into the mechanism of inhibition for the most potent inhibitor in the series, l-rhamnose 1C-phosphonate.

Following the thermal activation of Au25(SR)18 clusters for catalysis by x-ray absorption spectroscopy - Shivhare, Atal; Chevrier, Daniel M.; Purves, Randy W.; Scott, Robert W. J. (The Journal of Physical Chemistry C, 2013)
We show the thermal activation of phenylethanethiolate (L = SC₈H₉) and hexanethiolate (L = SC₆H₁₃) Au₂₅L₁₈ monolayer protected clusters (MPCs) on carbon black supports, followed by characterization with extended Xray absorption ﬁne structure (EXAFS) spectroscopy and transmission electron microscopy (TEM). EXAFS analysis shows that the thiolate stabilizers can be partially removed from the surface under mild heating conditions without signiﬁcant changes in the cluster size. The resulting clusters are shown to be catalytically active for the reduction catalysis of 4-nitrophenol. EXAFS and TEM data show that thermal treatment under air at 200 °C leads to nearly complete removal of all of the thiolate stabilizers with little to no growth in cluster size, while cluster sintering was seen at higher calcination temperatures. The maximum catalytic activity for Au₂₅(SC₈H₉)₁₈ MPCs was seen at 250 °C activation conditions. These results are consistent with results reported earlier for Au₂₅(SR)₁₈ clusters on ceria by Jin et al., who suggested that cluster integrity was maintained during mild activation conditions. Here, EXAFS data unambiguously show that while the cluster size does not grow signiﬁcantly, such mild heating conditions do lead to nearly complete removal of the thiolate stabilizers.

Identification and characterization of interactions between abscisic acid and human heat shock protein 70 family members - Kharenko, Olesya A.; Polichuk, Devin; Nelson, Ken M.; Abrams, Suzanne R.; Loewen, Michele C. (Journal of Biochemistry, 2013)
Abscisic acid (ABA) is a stress-inducible plant hormone comprising an inevitable component of the human diet. Recently, stress-induced accumulation of autocrine ABA was shown in humans, as well as ABA-mediated modulation of a number of disease-associated systems. Now, the application of a chemical proteomics approach to gain further insight into ABA mechanisms of action in mammalian cells is reported. An ABA mimetic photoaffinity probe was applied to intact mammalian insulinoma and embryonic cells, leading to the identification of heat shock protein 70 (HSP70) family members, (including GRP78 and HSP70-2) as putative human ABA-binding proteins. In vitro characterization of the ABA–HSP70 interactions yielded Kds in the 20–60 µM range, which decreased several fold in the presence of co-chaperone. However, ABA was found to have only variable- and co-chaperone-independent effects on the ATPase activity of these proteins. The potential implications of these ABA–HSP70 interactions are discussed with respect to the intracellular protein folding and extracellular receptor-like activities of these stress-inducible proteins. While mechanistic and functional relevance remain enigmatic, we conclude that ABA can bind to human HSP70 family members with physiologically relevant affinities and in a co-chaperone-dependent manner.
Keywords: abscisic acid; chemical proteomics; glucose-regulated protein 78; Heat shock protein 70; protein-ligand interaction

Gene expression profiles during embryo development in Brassica napus - Venglat, Prakash; Xiang, Daoquan; Yang, Hui; Wan, Lianglu; Tibiche, Chabane; Ross, Andrew; Wang, Edwin; Selvaraj, Gopalan; Datla, Raju (Plant Breeding, 2013)
The seed in angiosperms is produced through coordinated development of the embryo, endosperm and seed coat. In dicots, most of the seed mass is taken up by the embryo with nutritional reserves stored in the cotyledons. During embryogenesis, well-coordinated developmental and genetic programmes establish the embryonic body plan, and the associated complex metabolic pathways result in the production of diverse nutrients and deposition of important seed storage reserves. To gain insights into the genetic programmes that operate during embryo development in Brassica napus L. (canola), an important oilseed crop, we performed gene and protein expression analyses. We used the key stages from single-cell zygote to mature embryo to generate comprehensive EST and proteome data sets. Analysis of these data sets identified 20 183 genes and 2607 proteins that are differentially expressed across different stages of embryo development. B. napus genes share high degree of homology with Arabidopsis and display stage-specific and shared expression patterns associated with developmental and metabolic pathways. Together, this study has generated useful new molecular and genomic resources for embryo development in B. napus.
Keywords: Brassica napus; Embryogenesis; ESTs; Proteome - seed; Zygote

Arabidopsis Clade I TGA factors regulate apoplastic defences against the bacterial pathogen Pseudomonas syringae through endoplasmic reticulum-based processes - Wang, Lipu; Fobert, Pierre R. (PLoS ONE, 2013)
During the plant immune response, large-scale transcriptional reprogramming is modulated by numerous transcription (co) factors. The Arabidopsis basic leucine zipper transcription factors TGA1 and TGA4, which comprise the clade I TGA factors, have been shown to positively contribute to disease resistance against virulent strains of the bacterial pathogen Pseudomonas syringae. Despite physically interacting with the key immune regulator, NON-EXPRESSOR OF PATHOGENESIS-RELATED GENES 1 (NPR1), following elicitation with salicylic acid (SA), clade I function was shown to be largely independent of NPR1. Unlike mutants in NPR1, tga1-1 tga4-1 plants do not display reductions in steady-state levels of SA-pathway marker genes following treatment with this phenolic signaling metabolite or after challenge with virulent or avirulent P. syringae. By exploiting bacterial strains that have limited capacity to suppress Arabidopsis defence responses, the present study demonstrates that tga1-1 tga4-1 plants are compromised in basal resistance and defective in several apoplastic defence responses, including the oxidative burst of reactive oxygen species, callose deposition, as well as total and apoplastic PATHOGENESIS-RELATED 1 (PR-1) protein accumulation. Furthermore, analysis of npr1-1 and the tga1-1 tga4-1 npr1-1 triple mutant indicates that clade I TGA factors act substantially independent of NPR1 in mediating disease resistance against these strains of P. syringae. Increased sensitivity to the N-glycosylation inhibitor tunicamycin and elevated levels of endoplasmic reticulum (ER) stress marker genes encoding ER-resident chaperones in mutant seedlings suggest that loss of apoplastic defence responses is associated with aberrant protein secretion and implicate clade I TGA factors as positive regulators of one or more ER-related secretion pathways.

The development of a virtual simulator for training neurosurgeons to perform and perfect endoscopic endonasal transsphenoidal surgery - Rosseau, Gail; Bailes, Julian; del Maestro, Rolando; Cabral, Anne; Choudhury, Nusrat; Comas, Olivier; Debergue, Patricia; De Luca, Gino; Hovdebo, Jordan; Jiang, Di; Laroche, Denis; Neubauer, Andre; et al. (Neurosurgery, 2013)
BACKGROUND: A virtual reality (VR) neurosurgical simulator with haptic feedback may provide the best model for training and perfecting surgical techniques for transsphenoidal approaches to the sella turcica and cranial base. Currently there are 2 commercially available simulators: NeuroTouch (Cranio and Endo) developed by the National Research Council of Canada in collaboration with surgeons at teaching hospitals in Canada, and the Immersive Touch. Work in progress on other simulators at additional institutions is currently unpublished. OBJECTIVE: This article describes a newly developed application of the NeuroTouch simulator that facilitates the performance and assessment of technical skills for endoscopic endonasal transsphenoidal surgical procedures as well as plans for collecting metrics during its early use. METHODS: The main components of the NeuroTouch-Endo VR neurosurgical simulator are a stereovision system, bimanual haptic tool manipulators, and high-end computers. The software engine continues to evolve, allowing additional surgical tasks to be performed in the VR environment. Device utility for efficient practice and performance metrics continue to be developed by its originators in collaboration with neurosurgeons at several teaching hospitals in the United States. Training tasks are being developed for teaching 1- and 2-nostril endonasal transsphenoidal approaches. Practice sessions benefit from anatomic labeling of normal structures along the surgical approach and inclusion (for avoidance) of critical structures, such as the internal carotid arteries and optic nerves. CONCLUSION: The simulation software for NeuroTouch-Endo VR simulation of transsphenoidal surgery provides an opportunity for beta testing, validation, and evaluation of performance metrics for use in neurosurgical residency training.
Keywords: computer simulation; endoscopy; neurosurgery; training; transsphenoidal; virtual reality

Ring-opening polymerization of bile acid macrocycles by Candida antarctica lipase B - Strandman, Satu; Tsai, I-Huang; Lortie, Robert; Zhu, X. X. (Polymer Chemistry, 2013)
Lipase-catalyzed polymerization was explored as an alternative for Ru-catalyzed ring opening metathesis polymerization in the synthesis of polyesters bearing large functional moieties as part of the main chain. The selectivity of Candida antarctica lipase B (CALB) towards the functional groups of cholic acid (CA) was demonstrated, and the obtained CA-based polymers had relatively high molar masses, rubber-like elasticity, and glass transitions close to body temperature.
Keywords: Body temperature; Candida antarctica lipase B; Cholic acids; Functional moieties; Lipase-catalyzed; Macrocycles; Ring opening metathesis polymerization; Rubber-like elasticities

Collapse of rectangular granular blocks - Babaei, M. H.; Dabros, T.; Savage, S. B. (ISOPE 2012, Proceedings of the Twenty-Second International Offshore and Polar Engineering, 2013)
The collapse of bulk granular materials is of increasing importance in many applications in engineering and geophysics including processing of oil-sands and analysis of avalanches and landslides. The present work is primarily aimed at modelling of the deposition of tailings. This requires predicting the geometry of stable granular heaps, which poses a particular difficulty to available CFD models. In this paper we introduce a new plasticity model for the frictional stresses within the bulk granular material. The numerical simulations employ a two-fluid, one the granular material and the other the surrounding fluid, mixture approach to model the two-phase fluid-granular flow. Solution of the governing equations is carried out using COMSOL code. Results for two cases with small and large aspect ratios are presented. The results show the evolution of the internal flow and shape of the granular heap. The simulations examine the role of the height-to-length ratio on the final shapes. The results include comparisons between the present computations and available experimental measurements.
Keywords: gravitational collapse; granular material; Mohr-Coulomb plasticity; two-phase flow; numerical modelling; stable heap

Phycobilisome composition in Chondrus crispus (Gigartinales, Rhodophyta) from a wild type strain and its vegetatively derived green mutant - Cornish, M. Lynn; O'Leary, Stephen J. B.; Garbary, David J. (ALGAE, 2013)
Intact phycobilisomes from a wild-type red Chondrus crispus and its vegetatively derived green mutant were isolated by centrifugation through a discontinuous sucrose density gradient. Pigment composition was subsequently characterized by spectrophotometry. Vegetative thalli of the two strains grown together for six months in the laboratory resulted in different pigment profiles. Two pigmented phycobilisome bands appeared in the sucrose gradient of the wild-type alga, a purple coloured one, and a pink one, whereas only a single blue band appeared in the gradient of the green mutant. Spectrophotometric and fluorescence analyses identified the phycobiliprotein composition of the purple band as the typical phycoerythrin-phycocyanin-allophycocyanin complement in the wild-type, but there was no detectable phycoerythrin present in the blue band of the green mutant. Sodium dodecyl sulphate, preparative polyacrylamide gel electrophoresis analysis confirmed the presence of allophycocyanin subunits in all extracts, but firm evidence of an R-phycoerythrin linker polypeptide in the blue band was missing. These results highlight the ability of C. crispus to adapt to a phycoerythrin deficiency by adjusting light harvesting pigment ratios.
Keywords: Chondrus crispus; green mutant; phycobilisomes; phycoerythrin; pigmentation

Molecular mechanisms in the activation of Abscisic acid receptor PYR1 - Dorosh, Lyudmyla; Kharenko, Olesya A.; Rajagopalan, Nandhakishore; Loewen, Michele C.; Stepanova, Maria (PLoS Computational Biology, 2013)
The pyrabactin resistance 1 (PYR1)/PYR1-like (PYL)/regulatory component of abscisic acid (ABA) response (RCAR) proteins comprise a well characterized family of ABA receptors. Recent investigations have revealed two subsets of these receptors that, in the absence of ABA, either form inactive homodimers (PYR1 and PYLs 1–3) or mediate basal inhibition of downstream target type 2C protein phosphatases (PP2Cs; PYLs 4–10) respectively in vitro. Addition of ABA has been shown to release the apo-homodimers yielding ABA-bound monomeric holo-receptors that can interact with PP2Cs; highlighting a competitive-interaction process. Interaction selectivity has been shown to be mediated by subtle structural variations of primary sequence and ligand binding effects. Now, the dynamical contributions of ligand binding on interaction selectivity are investigated through extensive molecular dynamics (MD) simulations of apo and holo-PYR1 in monomeric and dimeric form as well as in complex with a PP2C, homology to ABA insensitive 1 (HAB1). Robust comparative interpretations were enabled by a novel essential collective dynamics approach. In agreement with recent experimental findings, our analysis indicates that ABA-bound PYR1 should efficiently bind to HAB1. However, both ABA-bound and ABA-extracted PYR1-HAB1 constructs have demonstrated notable similarities in their dynamics, suggesting that apo-PYR1 should also be able to make a substantial interaction with PP2Cs, albeit likely with slower complex formation kinetics. Further analysis indicates that both ABA-bound and ABA-free PYR1 in complex with HAB1 exhibit a higher intra-molecular structural stability and stronger inter-molecular dynamic correlations, in comparison with either holo- or apo-PYR1 dimers, supporting a model that includes apo-PYR1 in complex with HAB1. This possibility of a conditional functional apo-PYR1-PP2C complex was validated in vitro. These findings are generally consistent with the competitive-interaction model for PYR1 but highlight dynamical contributions of the PYR1 structure in mediating interaction selectivity suggesting added degrees of complexity in the regulation of the competitive-inhibition.
Keywords: hondrus crispus; green mutant; phycobilisomes; phycoerythrin; pigmentation

Transcriptome analysis based on next-generation sequencing of non-model plants producing specialized metabolites of biotechnological interest - Xiao, Mei; Zhang, Ye; Chen, Xue; Lee, Eun-Jeong; Barber, Carla J. S.; Chakrabarty, Romit; Desgagné-Penix, Isabel; Haslam, Tegan M.; Kim, Yeon-Bok; Liu, Enwu; MacNevin, Gillian; Masada-Atsumi, Sayaka; et al. (Journal of Biotechnology, 2013)
Plants produce a vast array of specialized metabolites, many of which are used as pharmaceuticals, flavors, fragrances, and other high-value fine chemicals. However, most of these compounds occur in non-model plants for which genomic sequence information is not yet available. The production of a large amount of nucleotide sequence data using next-generation technologies is now relatively fast and cost-effective, especially when using the latest Roche-454 and Illumina sequencers with enhanced base-calling accuracy. To investigate specialized metabolite biosynthesis in non-model plants we have established a data-mining framework, employing next-generation sequencing and computational algorithms, to construct and analyze the transcriptomes of 75 non-model plants that produce compounds of interest for biotechnological applications. After sequence assembly an extensive annotation approach was applied to assign functional information to over 800,000 putative transcripts. The annotation is based on direct searches against public databases, including RefSeq and InterPro. Gene Ontology (GO), Enzyme Commission (EC) annotations and associated Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway maps are also collected. As a proof-of-concept, the selection of biosynthetic gene candidates associated with six specialized metabolic pathways is described. A web-based BLAST server has been established to allow public access to assembled transcriptome databases for all 75 plant species of the PhytoMetaSyn Project (www.phytometasyn.ca).
Keywords: Bioinformatics; Illumina GA sequencing; Plant specialized metabolites; RNA-seq; Roche-454 pyrosequencing; Transcriptomics

An atypical pattern of accumulation of scopolamine and other tropane alkaloids and expression of alkaloid pathway genes in Hyoscyamus senecionis - Dehghan, Esmail; Ahmadi, Farajollah Shahriari; Ravandi, Elnaz Ghotbi; Reed, Darwin W.; Covello, Patrick S.; Bahrami, Ahmad Reza (Plant Physiology and Biochemistry, 2013)
A cDNA encoding hyoscyamine 6β-hydroxylase (H6H, EC 1.14.11.11), a bifunctional enzyme catalyzing the last two steps in the scopolamine biosynthetic pathway, was isolated from Hyoscyamus senecionis, a medicinal plant endemic to the Iranian plateau. Expression analysis indicates that Hsh6h is expressed in all tested organs of H. senecionis including roots, rhizomes, leaves, stems and flowers unlike the other tropane alkaloid producing species. In parallel to this, in leaves, levels of scopolamine, the product of H6H, were higher than the substrate hyoscyamine. These data suggest that not only does the conversion of hyoscyamine to scopolamine take place in the root, followed by translocation to aerial parts, but also accumulated hyoscyamine in the aerial parts may be converted to scopolamine by activity of HsH6H. Analysis of expression profiles of putrescine N-methyltransferase and tropinone reductase I and II genes also indicates the organ-independent expression of these genes. Here we also introduce H. senecionis as an important tropane alkaloid producing species with its thick underground parts as a source of hyoscyamine, while its leaves can be considered as a source of scopolamine.
Keywords: BSTFA; Expression profile; GC; GC-MS; Hyoscyamine 6β-hydroxylase (H6H); Hyoscyamus senecionis; IPTG; MS; ORF; PMT; Solanaceae; TMCS; TRI; TRII; Tropane alkaloids; X-Gal

Evaluation of deep eutectic solvent–water binary mixtures for lipase-catalyzed lipophilization of phenolic acids - Durand, Erwann; Lecomte, Jérôme; Baréa, Bruno; Dubreucq, Eric; Lortie, Robert; Villeneuve, Pierre (Green Chemistry, 2013)
This work reports the first lipase-catalyzed reactions between substrates of different polarities using deep eutectic solvents as a medium. The model reaction consisted of a lipophilization process based on the alcoholysis of phenolic esters using immobilized Candida antarctica lipase B as a biocatalyst. Results showed that water could dramatically improve the lipase activity and change the reactivity of phenolic substrates. Indeed, very low conversions (<2%) were observed in pure DES, whereas in DES–water binary mixtures, quantitative conversions were achieved. After investigating the role of various parameters, such as the substrate concentration and ratio, pH or thermodynamic activity of water, the effect of the presence of water in pure DES based on urea or glycerol was discussed. In this paper, we propose new perspectives for the enzymatic modification of polar substrates using this novel generation of green, inexpensive and easy-to-handle solvents.

Fabrication and characterization of nanotemplated carbon monolithic material - He, Xiaoyun; Nesterenko, Ekaterina P.; Nesterenko, Pavel N.; Brabazon, Dermot; Zhou, Lin; Glennon, Jeremy D.; Luong, John H. T.; Paull, Brett (ACS Applied Materials & Interfaces, 2013)
A novel hierarchical nanotemplated carbon monolithic rod (NTCM) was prepared using a novel facile nanotemplating approach. The NTCM was obtained using C60-fullerene modified silica gels as hard templates, which were embedded in a phenolic resin containing a metal catalyst for localized graphitization, followed by bulk carbonization, and template and catalyst removal. TEM, SEM, and BET measurements revealed that NTCM possessed an integrated open hierarchical porous structure, with a trimodal pore distribution. This porous material also possessed a high mesopore volume and narrow mesopore size distribution. During the course of carbonization, the C60 conjugated to aminated silica was partly decomposed, leading to the formation of micropores. The Raman signature of NTCM was very similar to that of multiwalled carbon nanotubes as exemplified by three major peaks as commonly observed for other carbon materials, i.e., the sp3 and sp2 carbon phases coexisted in the sample. Surface area measurements were obtained using both nitrogen adsorption/desorption isotherms (BET) and with a methylene blue binding assay, with BET results showing the NTCM material possessed an average specific surface area of 435 m2 g–1, compared to an area of 372 m2 g–1 obtained using the methylene blue assay. Electrochemical studies using NTCM modified glassy carbon or boron doped diamond (BDD) electrodes displayed quasi-reversible oxidation/reduction with ferricyanide. In addition, the BDD electrode modified with NTCM was able to detect hydrogen peroxide with a detection limit of below 300 nM, whereas the pristine BDD electrode was not responsive to this target compound.
Keywords: carbon monolith; electrochemical behavior; fullerene C60; nanotemplating

Adsorption and desorption of Methylene blue on porous Carbon monoliths and nanocrystalline cellulose - He, Xiaoyun; Male, Keith B.; Nesterenko, Pavel N.; Brabazon, Dermot; Paull, Brett; Luong, John H. T. (ACS Applied Materials & Interfaces, 2013)
The dynamic batch adsorption of methylene blue (MB), a widely used and toxic dye, onto nanocrystalline cellulose (NCC) and crushed powder of carbon monolith (CM) was investigated using the pseudo-first- and -second-order kinetics. CM outperformed NCC with a maximum capacity of 127 mg/g compared to 101 mg/g for NCC. The Langmuir isotherm model was applicable for describing the binding data for MB on CM and NCC, indicating the homogeneous surface of these two materials. The Gibbs free energy of −15.22 kJ/mol estimated for CM unravelled the spontaneous nature of this adsorbent for MB, appreciably faster than the use of NCC (−4.47 kJ/mol). Both pH and temperature exhibited only a modest effect on the adsorption of MB onto CM. The desorption of MB from CM using acetonitrile was very effective with more than 94 % of MB desorbed from CM within 10 min to allow the reusability of this porous carbon material. In contrast, acetonitrile was less effective than ethanol in desorbing MB from NCC. The two solvents were incapable of completely desorbing MB on commercial granular coal-derived activated carbon.
Keywords: activated carbon; adsorption; carbon monolith; desorption; kinetics; methylene blue; nanocrystalline cellulose

Anaerobic digestates are useful nutrient sources for microalgae cultivation : functional coupling of energy and biomass production - Bjornsson, William J.; Nicol, Robert W.; Dickinson, Kathryn E.; McGinn, Patrick J. (Journal of Applied Phycology, 2013)
We investigated the extent to which nitrogenous and phosphorus nutrients from liquid anaerobic digestates could be recycled for photosynthetic growth of a microalga, Scenedesmus sp. AMDD. Digestates recovered from the anaerobic digestion of cow manure and swine manure and a co-digestion of swine manure and algal biomass were diluted in distilled water and used for algal growth with and without supplemental CO2 addition. Nutrient assimilation and final biomass yield were retarded in all but the swine manure/algae co-digestate cultures supplemented with high CO2. Swine manure digestate cultures supplemented with the typical complement of micronutrients normally added with a commonly used growth medium or with Fe/EDTA failed to grow any better than unamended controls. When the culture medium was prepared by blending swine manure digestate with 25 or 50 % algal biomass digestate, diluting it with lake water or by supplementing with magnesium, nutrient assimilation and final algal biomass yields were maximized, indicating that magnesium was critically limiting for algal growth in swine manure digestates. Magnesium amendment thus appears to be essential if nutrients from swine manure digestates are recycled for algal growth. No such requirement is necessary for recycling nutrients from digestates generated wholly or in part from algal biomass.
Keywords: Anaerobic digestates; Biomass; Nutrient recycling; Photosynthesis

New diacylglyceryltrimethylhomoserines from the marine microalga Nannochloropsis granulata and their nitric oxide inhibitory activity - Banskota, Arjun H.; Stefanova, Roumiana; Sperker, Sandra; McGinn, Patrick J. (Journal of Applied Phycology, 2013)
Chemical investigation of polar lipids from the marine eustigmatophyte microalga Nannochloropsis granulata led to the isolation of six betaine lipid diacylglyceryltrimethylhomoserine (DGTS), namely, (2S)-1,2-bis-O-eicosapentaenoylglyceryl-3-O-4′-(N,N,N-trimethyl)-homoserine (1), (2S)-1-O-eicosapentaenoyl-2-O-arachidonoylglyceryl-3-O-4′-(N,N,N-trimethyl)-homoserine (2), (2S)-1-O-eicosapentaenoyl-2-O-myristoylglyceryl-3-O-4′-(N,N,N-trimethyl)-homoserine (3), (2S)-1-O-eicosapentaenoyl-2-O-palmitoylglyceryl-3-O-4′-(N,N,N-trimethyl)-homoserine (4), (2S)-1-O-eicosapentaenoyl-2-O-palmitoleoylglyceryl-3-O-4′-(N,N,N-trimethyl)-homoserine (5), and (2S)-1-O-eicosapentaenoyl-2-O-linoleoylglyceryl-3-O-4′-(N,N,N-trimethyl)-homoserine (6). Structures of the isolated DGTSs were elucidated based on both spectroscopic technique and degradation methods. This is the first report of isolation of 1 in pure state, and 2–6 are all new compounds. The isolated betaine lipids showed dose-dependent nitric oxide (NO) inhibitory activity against lipopolysaccharide-induced nitric oxide production in RAW264.7 macrophage cells. Further study suggested that these betaine lipids (1–6) inhibit NO production in RAW264.7 macrophage cells through downregulation of inducible nitric oxide synthase expression, indicating the possible use as an anti-inflammatory agent. This is the first report of DGTS with anti-inflammatory activity.
Keywords: Betaine lipid; Diacylglyceryltrimethylhomoserine (DGTS); Inducible nitric oxide synthase; Microalgae; Nannochloropsis granulata; Nitric oxide

Aeromonas salmonicida Ati2 is an effector protein of the type three secretion system - Dallaire-Dufresne, Stéphanie; Barbeau, Xavier; Sarty, Darren; Tanaka, Katherine H.; Denoncourt, Alix M.; Lagüe, Patrick; Reith, Michael E.; Charette, Steve J. (Microbiology, 2013)
The bacterium Aeromonas salmonicida, a fish pathogen, uses the type three secretion system (TTSS) to inject effector proteins into host cells to promote the infection. The study of the genome of A. salmonicida has revealed the existence of Ati2, a potential TTSS effector protein. In the present study, a structure–function analysis of Ati2 has been done to determine its role in the virulence of A. salmonicida. Biochemical assays revealed that Ati2 is secreted into the medium in a TTSS-dependent manner. Protein sequence analyses, molecular modelling and biochemical assays demonstrated that Ati2 is an inositol polyphosphate 5-phosphatase, which hydrolyses PtdIns(4,5)P2 and PtdIns(3,4,5)P3 in a way similar to VPA0450, a protein from Vibrio parahaemolyticus having high sequence similarity with Ati2. Mutants of Ati2 with altered amino acids at two different locations in the catalytic site displayed no phosphatase activity. Wild-type and mutant forms of Ati2 were cloned into expression systems for Dictyostelium discoideum, a soil amoeba used as an alternative host to study A. salmonicida virulence. Expression tests allowed us to demonstrate that Ati2 is toxic for the host cell in a catalytic-dependent manner. Finally, this study demonstrated the existence of a new TTSS effector protein in A. salmonicida.

The impact of nitric oxide toxicity on the evolution of the glutathione transferase superfamily : a proposal for an evolutionary driving force - Bocedi, Alessio; Fabrini, Raffaele; Farrotti, Andrea; Stella, Lorenzo; Ketterman, Albert J.; Pedersen, Jens Z.; Allocati, Nerino; Lau, Peter C. K.; Grosse, Stephan; Eltis, Lindsay D.; Ruzzini, Antonio; Edwards, Thomas E.; et al. (Journal of Biological Chemistry, 2013)
Glutathione transferases (GSTs) are protection enzymes capable of conjugating glutathione (GSH) to toxic compounds. During evolution an important catalytic cysteine residue involved in GSH activation was replaced by serine or, more recently, by tyrosine. The utility of these replacements represents an enigma because they yield no improvements in the affinity toward GSH or in its reactivity. Here we show that these changes better protect the cell from nitric oxide (NO) insults. In fact the dinitrosyl·diglutathionyl·iron complex (DNDGIC), which is formed spontaneously when NO enters the cell, is highly toxic when free in solution but completely harmless when bound to GSTs. By examining 42 different GSTs we discovered that only the more recently evolved Tyr-based GSTs display enough affinity for DNDGIC (KD < 10−9 M) to sequester the complex efficiently. Ser-based GSTs and Cys-based GSTs show affinities 102–104 times lower, not sufficient for this purpose. The NO sensitivity of bacteria that express only Cys-based GSTs could be related to the low or null affinity of their GSTs for DNDGIC. GSTs with the highest affinity (Tyr-based GSTs) are also over-represented in the perinuclear region of mammalian cells, possibly for nucleus protection. On the basis of these results we propose that GST evolution in higher organisms could be linked to the defense against NO.
Keywords: Enzyme Inhibitors, Enzyme Structure, Enzymes, Evolution, Nitric Oxide, Dinitrosyl Iron Complex, Glutathione Transferase

Mapping of quantitative trait Loci underlying cold tolerance in rice seedlings via high-throughput sequencing of pooled extremes - Yang, Zemao; Huang, Daiquing; Tang, Weiqi; Zheng, Yan; Liang, Kangjing; Cutler, Adrian J.; Wu, Weiren (PLoS ONE, 2013)
Low temperature is a major limiting factor in rice growth and development. Mapping of quantitative trait loci (QTLs) controlling cold tolerance is important for rice breeding. Recent studies have suggested that bulked segregant analysis (BSA) combined with next-generation sequencing (NGS) can be an efficient and cost-effective way for QTL mapping. In this study, we employed NGS-assisted BSA to map QTLs conferring cold tolerance at the seedling stage in rice. By deep sequencing of a pair of large DNA pools acquired from a very large F3 population (10,800 individuals), we obtained ~450,000 single nucleotide polymorphisms (SNPs) after strict screening. We employed two statistical methods for QTL analysis based on these SNPs, which yielded consistent results. Six QTLs were mapped on chromosomes 1, 2, 5, 8 and 10. The three most significant QTLs on chromosomes 1, 2 and 8 were validated by comparison with previous studies. Two QTLs on chromosomes 2 and 5 were also identified previously, but at the booting stage rather than the seedling stage, suggesting that some QTLs may function at different developmental stages, which would be useful for cold tolerance breeding in rice. Compared with previously reported QTL mapping studies for cold tolerance in rice based on the traditional approaches, the results of this study demonstrated the advantages of NGS-assisted BSA in both efficiency and statistical power.
Keywords: article; booting stage; bulked segregant analysis; chromosome 1; chromosome 10; chromosome 2; chromosome 5; chromosome 8; cold tolerance; developmental stage; DNA sequence; high throughput sequencing; next generation sequencing; nonhuman; plant breeding; quantitative trait locus mapping; rice; seedling; single nucleotide polymorphism

CE with a boron-doped diamond electrode for trace detection of endocrine disruptors in water samples - Browne, Damien J.; Zhou, Lin; Luong, John H. T.; Glennon, Jeremy D. (ELECTROPHORESIS, 2013)
Off-line SPE and CE coupled with electrochemical detection have been used for the determination of bisphenol A (BPA), bisphenol F, 4-ethylphenol, and bisphenol A diglycidyl ether in bottled drinking water. The use of boron-doped diamond electrode as an electrochemical detector in amperometric mode that provides a favorable analytical performance for detecting these endocrine-disrupting compounds, such as lower noise levels, higher peak resolution with enhanced sensitivity, and improved resistance against electrode passivation. The oxidative electrochemical detection of the endocrine-disrupting compounds was accomplished by boron-doped diamond electrode poised at +1.4 V versus Ag/AgCl without electrode pretreatment. An off-line SPE procedure (Bond Elut® C18 SPE cartridge) was utilized to extract and preconcentrate the compounds prior to separation and detection. The minimum concentration detectable for all four compounds ranged from 0.01 to 0.06 μM, having S/N equal to three. After exposing the plastic bottle water container under sunlight for 7 days, the estimated concentration of BPA in the bottled drinking water was estimated to be 0.03 μM. This proposed approach has great potential for rapid and effective determination of BPA content present in water packaging of plastic bottles that have been exposed to sunlight for an extended period of time.
Keywords: Boron-doped diamond electrode; Capillary electrophoresis; Endocrine disruptors

Allosteric regulation of the calcium-sensing receptor in obese individuals - He, Yonghan; Perry, Ben; Bi, Mingxin; Sun, Hui; Zhao, Tiantian; Li, Ying; Sun, Changhao (International Journal of Molecular Medicine, 2013)
We have previously reported that the calcium-sensing receptor (CaSR) plays an important role in modulating lipid metabolism under low calcium conditions. The aim of this study was to identify possible regulators of CaSR and the mechanisms of action of CaSR in obese individuals. Subcutaneous fat samples were obtained from 10 obese and 10 non-obese males undergoing elective abdominal surgery. Visceral fat pads were obtained from 12 obese and 12 non‑obese male rats. Serum lipid, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) concentrations, as well as the gene and protein expression of CaSR in the white adipose tissue of obese subjects and rats were determined. Serum total calcium, vitamin D, parathyroid hormone (PTH) and amino acid levels in human subjects were measured. Intracellular calcium and cyclic adenosine monophosphate (cAMP) levels in rat adipocytes were measured by laser scanning confocal microscopy and ELISA, respectively. The results revealed that serum triglyceride (TG), total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C), TNF-α, IL-6 and PTH levels were significantly higher in the obese individuals versus the controls. By contrast, serum vitamin D and amino acid concentrations were lower in the obese individuals versus the controls. In addition, intracellular calcium levels were higher, while cAMP levels were lower in the obese rat adipocytes compared with the control group. However, the gene and protein expression of CaSR in white adipose tissue did not differ between the obese groups and the controls. Thus, these results suggest that CaSR functions not through its expression, but rather through allosteric regulation in obese individuals.
Keywords: Amino Acids; Calcium; Calcium-Sensing Recepor; Cytokine; Obesity

Ursolic acid inhibits Adipogenesis in 3T3-L1 Adipocytes through LKB1/AMPK pathway - He, Yonghan; Li, Ying; Zhao, Tiantian; Wang, Yanwen; Sun, Changhao (PLoS ONE, 2013)
Background:Ursolic acid (UA) is a triterpenoid compound with multiple biological functions. This compound has recently been reported to possess an anti-obesity effect; however, the mechanisms are less understood.Objective:As adipogenesis plays a critical role in obesity, the present study was conducted to investigate the effect of UA on adipogenesis and mechanisms of action in 3T3-L1 preadipocytes.Methods and Results:The 3T3-L1 preadipocytes were induced to differentiate in the presence or absence of UA for 6 days. The cells were determined for proliferation, differentiation, fat accumulation as well as the protein expressions of molecular targets that regulate or are involved in fatty acid synthesis and oxidation. The results demonstrated that ursolic acid at concentrations ranging from 2.5 μM to 10 μM dose-dependently attenuated adipogenesis, accompanied by reduced protein expression of CCAAT element binding protein β (C/EBPβ), peroxisome proliferator-activated receptor γ (PPARγ), CCAAT element binding protein α (C/EBPα) and sterol regulatory element binding protein 1c (SREBP-1c), respectively. Ursolic acid increased the phosphorylation of acetyl-CoA carboxylase (ACC) and protein expression of carnitine palmitoyltransferase 1 (CPT1), but decreased protein expression of fatty acid synthase (FAS) and fatty acid-binding protein 4 (FABP4). Ursolic acid increased the phosphorylation of AMP-activated protein kinase (AMPK) and protein expression of (silent mating type information regulation 2, homolog) 1 (Sirt1). Further studies demonstrated that the anti-adipogenic effect of UA was reversed by the AMPK siRNA, but not by the Sirt1 inhibitor nicotinamide. Liver kinase B1 (LKB1), the upstream kinase of AMPK, was upregulated by UA. When LKB1 was silenced with siRNA or the inhibitor radicicol, the effect of UA on AMPK activation was diminished.Conclusions:Ursolic acid inhibited 3T3-L1 preadipocyte differentiation and adipogenesis through the LKB1/AMPK pathway. There is potential to develop UA into a therapeutic agent for the prevention or treatment of obesity.
Keywords: animal cell; apoptosis; article; cell differentiation; cell proliferation; cell viability; concentration response; controlled study; embryo; lipid storage; lipolysis; mouse; nonhuman; proadipocyte; protein expression; protein phosphorylation

The LuWD40-1 gene encoding WD repeat protein regulates growth and pollen viability in flax (Linum Usitatissimum L.) - Kumar, Santosh; Jordan, Mark C.; Datla, Raju; Cloutier, Sylvie (PLoS ONE, 2013)
As a crop, flax holds significant commercial value for its omega-3 rich oilseeds and stem fibres. Canada is the largest producer of linseed but there exists scope for significant yield improvements. Implementation of mechanisms such as male sterility can permit the development of hybrids to assist in achieving this goal. Temperature sensitive male sterility has been reported in flax but the leakiness of this system in field conditions limits the production of quality hybrid seeds. Here, we characterized a 2,588 bp transcript differentially expressed in male sterile lines of flax. The twelve intron gene predicted to encode a 368 amino acid protein has five WD40 repeats which, in silico, form a propeller structure with putative nucleic acid and histone binding capabilities. The LuWD40-1 protein localized to the nucleus and its expression increased during the transition and continued through the vegetative stages (seed, etiolated seedling, stem) while the transcript levels declined during reproductive development (ovary, anthers) and embryonic morphogenesis of male fertile plants. Knockout lines for LuWD40-1 in flax failed to develop shoots while overexpression lines showed delayed growth phenotype and were male sterile. The non-viable flowers failed to open and the pollen grains from these flowers were empty. Three independent transgenic lines overexpressing the LuWD40-1 gene had ~80% non-viable pollen, reduced branching, delayed flowering and maturity compared to male fertile genotypes. The present study provides new insights into a male sterility mechanism present in flax.
Keywords: anther; article; cell nucleus; cellular distribution; controlled study; epidermis cell; flowering; intron; Linum; Linum usitatisimmum; LuWD40-1 gene; male plant; male sterility; morphogenesis; nonhuman; nucleotide sequence; ovary development; phenotype; plant growth; pollen; promoter region; protein localization; sequence analysis; shoot; transgenic plant; vegetative stage

Effects of combined ‘all-fish’ growth hormone transgenics and triploidy on growth and nutrient utilization of Atlantic salmon (Salmo salar L.) fed a practical grower diet of known composition - Tibbetts, S. M.; Wall, C. L.; Barbosa-Solomieu, V.; Bryenton, M. D.; Plouffe, D. A.; Buchanan, J. T.; Lall, S. P. (Aquaculture, 2013)
Full-sibling, size-matched ‘all-fish’ growth hormone transgenic (TG; gene construct EO-1α) and non-transgenic (NTG) Atlantic salmon (Salmo salar L.) comprised of conventional diploid (DIP) and reproductively-sterile triploid (TRIP) fish were fed the same experimental grower diet in freshwater until they tripled their weight. The study was conducted to provide baseline data on growth performance, feed efficiency, nutrient digestibility, skeletal disorders, bone ash content and bone mineral composition of NTG/DIP, NTG/TRIP, TG/DIP and TG/TRIP fish and to determine if a practical grower diet for conventional NTG/DIP Atlantic salmon requires modification for TG/TRIP fish. TG fish consumed a significantly higher amount of feed on a daily basis but due to enhanced growth rates, better feed conversion ratios and higher nitrogen retention efficiency they achieved target weight gain in a considerably shorter period (40%) than NTG fish. Total feed required to produce the same fish biomass was reduced by 25%; representative of a significant reduction in overall feed intake. Of TG fish, TRIP had some significant effects on production traits primarily due to lower feed intake relative to DIP fish. Although feed intake was lower in TG/TRIP fish, feed efficiency, digestibility and nutrient retention efficiencies were equal to those of TG/DIP fish and, without exception; TG/TRIP fish out-performed their conventional NTG counterparts, regardless of ploidy. TG/DIP and TG/TRIP fish demonstrated a higher cellular capacity to direct dietary non-protein energy towards satisfying their daily metabolic energy requirements, allowing for a higher proportion of dietary amino acids to be directed towards protein biosynthesis; rather than catabolised as a dietary energy source. Since dietary protein is the largest and most expensive component of salmon feeds and also the major source of nitrogenous pollution from salmon farming, this could represent a highly beneficial alteration of energy metabolism which could result in more economical and ecologically-sustainable Atlantic salmon aquaculture, especially when conducted in closed-containment land-based systems. Although bone ash content of TG fish was slightly lower than NTG fish, no significant differences in key bone mineral composition were observed and the occurrence of skeletal disorders was low (< 4%), regardless of transgenics or ploidy.
Keywords: Atlantic salmon; Energy metabolism; Nutrition; Protein utilization; Transgenics; Triploidy

Wall proximity effects on flow over a simple membrane spacer - Mahdavifar, A.; Pollard, A.; Pharoah, J. G.; Beale, S. B. (Computers & Fluids, 2013)
Spacer-filled channels are employed in membrane modules in many industrial applications where feedflow spacers (employed to separate membrane sheets and create flow channels) tend to enhance mass transport characteristics (and possibly) mitigate fouling and concentration polarization phenomena. In this work direct numerical simulation was performed for the flow in spacer-filled channels to obtain a better understanding of fluid flow phenomena in these assemblies. Reynolds numbers of 300, 500 and 800 were considered. The effect of spacer location was also studied for three different configurations: spacer at the centre of the channel, off-centre, and attached to the wall. Instantaneous velocity fields and flow structures, such as boundary layer separation on the walls and on the cylinder, eddies on the walls, recirculation regions and vortex shedding were investigated. A Fourier analysis was carried out on the time series velocity data. Using this analysis the Strouhal number was calculated and the development of the flow towards a broader turbulent state at higher Reynolds number was captured. Other statistical characteristics such as time-averaged velocities and wall shear rates are obtained and discussed. The average pressure loss was calculated for the channels and found to be highest for spacer at the centre of the channel and lowest for spacer attached to the wall.
Keywords: membranes; DNS; wall proximity

Quality assessment of Japanese knotweed (Fallopia japonica) grown on Prince Edward Island as a source of resveratrol - Chen, Huaguo; Tuck, Tina; Ji, Xiuhong; Zhou, Xin; Kelly, Glen; Cuerrier, Alain; Zhang, Junzeng (Journal of Agricultural and Food Chemistry, 2013)
Japanese knotweed (Fallopia japonica, also known as Polygonum cuspidatum) is a common invasive plant species on Prince Edward Island (PEI), Canada, whereas it has been used in Chinese medicine and more recently as a raw material for extracting resveratrol. This paper reports on the quantification of resveratrol, polydatin, emodin, and physcion in roots, stems, and leaves of Japanese knotweed samples from PEI and British Columbia (BC), Canada, and nine provinces of China, by ultraperformance liquid chromatography (UPLC). The results showed that the root contains a much higher level of resveratrol than the stem and leaf, and it is accumulated in its highest level in October. PEI-grown knotweed contains similar levels of resveratrol and polydatin compared to Chinese samples collected in the month of October, but the contents of the other anthraquinones (emodin and physcion) are different. As such, Japanese knotweed grown in PEI could be a commercially viable source of raw material for resveratrol production; however, caution has to be taken in harvesting the right plant species.
Keywords: Fallopia japonica; Japanese knotweed; quality assessment; resveratrol; UPLC

Abscisic acid binds to recombinant Arabidopsis thaliana G-protein coupled receptor-type G-protein 1 in Sacaromycese cerevisiae and in vitro - Kharenko, Olesya A.; Choudhary, Pooja; Loewen, Michele C. (Plant Physiology and Biochemistry, 2013)
The G-protein coupled receptor-type G-proteins (GTG) 1 and 2 from Arabidopsis thaliana have been proposed to function in the modulation of abscisic acid (ABA) mediated responses to stress and development. In particular it has been suggested that they function as ABA receptors based on in planta and in vitro analyses. However a recent independent report was inconsistent with this, suggesting that there is no link between the GTGs and ABA in planta. Here we provide an independent assessment of the ability of ABA to bind to recombinant GTG1 in vitro and in vivo in Sacaromycese cerevisiae. Radio-labelled binding assays on enriched lipid-reconstituted recombinant GTG1, demonstrated specific concentration dependent binding of [3H]-ABA with a dissociation constant (KD) of 80 nM, corroborating previous reports. Assessment of the binding of [3H]-ABA to intact GTG1 expressing yeast, showed GTG1-dependent binding in vivo, yielding a physiologically relevant KD of 0.6 μM. Together these results provide independent evidence of a binding-interaction between ABA and GTG1 in vitro and in vivo, in support of the previously proposed possibility of a biologically relevant interaction between GTG1 and ABA.
Keywords: G-protein couple receptor-type G-Protein; Abscisic acid; Recombinant expression; S. cerevisiae; Protein–ligand interaction

Bioactive components of the edible strain of red alga, Chondrus crispus, enhance oxidative stress tolerance in Caenorhabditis elegans - Sangha, Jatinder, Singh; Fan, Di; Banskota, Arjun H.; Stefanova, Roumiana; Khan, Wajahatullah; Hafting, Jeff; Craigie, James; Critchley, Alan T.; Prithiviraj, Balakrishnan (Journal of Functional Foods, 2013)
Seaweeds are rich sources of bioactive compounds with potential health benefits. Anti-stress effects of the cultivated red alga, Chondrus crispus, were investigated in the Caenorhabditis elegans model. Methanolic extracts of C. crispus (CCME) enhanced C. elegans tolerance to juglone-induced oxidative stress and increased life span; however water extracts did not show such effects. CCME treatment reduced reactive oxygen species (ROS) in the worms and increased the transcription of stress response genes; sod3, hsp16.2, daf16 and skn1. The chemical profile of CCME revealed the presence of unsaturated fatty acids, pigments, galactolipids, floridoside, isothionic acid, taurine, phenylalanine and l-citruline. Bioassay guided fractionation revealed that fatty acids, lipids and pigments imparted stress tolerance. Taken together, our results suggest that organic fractions of cultivated C. crispus impart oxidative stress tolerance in C. elegans, possibly by altering the stress response pathways.
Keywords: Caenorhabditis elegans; Chondrus crispus; Cultivated seaweeds; Functional foods; Stress tolerance

Radicicol, a heat shock protein 90 inhibitor, inhibits differentiation and adipogenesis in 3T3-L1 preadipocytes - He, Yonghan; Li, Ying; Zhang, Shuocheng; Perry, Ben; Zhao, Tiantian; Wang, Yanwen; Sun, Changhao (Biochemical and Biophysical Research Communications, 2013)
Heat shock protein 90 (Hsp90) is involved in various cellular processes, such as cell proliferation, differentiation and apoptosis. As adipocyte differentiation plays a critical role in obesity development, the present study investigated the effect of an Hsp90 inhibitor radicicol on the differentiation of 3T3-L1 preadipocytes and potential mechanisms. The cells were treated with different concentrations of radicicol during the first 8 days of cell differentiation. Adipogenesis, the expression of adipogenic transcriptional factors, differentiation makers and cell cycle were determined. It was found that radicicol dose-dependently decreased intracellular fat accumulation through down-regulating the expression of peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT element binding protein α (C/EBPα), fatty acid synthase (FAS) and fatty acid-binding protein 4 (FABP4). Flow cytometry analysis revealed that radicicol blocked cell cycle at G1-S phase. Radicicol redcued the phosphorylation of Akt while showing no effect on β-catenin expression. Radicicol decreased the phosphorylation of phosphoinositide-dependent kinase 1 (PDK1). The results suggest that radicicol inhibited 3T3-L1 preadipocyte differentiation through affecting the PDK1/Akt pathway and subsequent inhibition of mitotic clonal expansion and the expression/activity of adipogenic transcriptional factors and their downstream adipogenic proteins.
Keywords: Radicicol; Heat shock protein; Differentiation; Adipocytes

Collagen morphology and texture analysis : from statistics to classification - Mostaço-Guidolin, Leila B.; Ko, Alex C.-T.; Wang, Fei; Xiang, Bo; Hewko, Mark; Tian, Ganghong; Major, Arkady; Shiomi, Masashi; Sowa, Michael G. (Scientific Reports, 2013)
In this study we present an image analysis methodology capable of quantifying morphological changes in tissue collagen fibril organization caused by pathological conditions. Texture analysis based on first-order statistics (FOS) and second-order statistics such as gray level co-occurrence matrix (GLCM) was explored to extract second-harmonic generation (SHG) image features that are associated with the structural and biochemical changes of tissue collagen networks. Based on these extracted quantitative parameters, multi-group classification of SHG images was performed. With combined FOS and GLCM texture values, we achieved reliable classification of SHG collagen images acquired from atherosclerosis arteries with >90% accuracy, sensitivity and specificity. The proposed methodology can be applied to a wide range of conditions involving collagen re-modeling, such as in skin disorders, different types of fibrosis and muscular-skeletal diseases affecting ligaments and cartilage.
Keywords: SHG, collagen, classification, texture, gray level co-occurance matrix, multiphoton microscopy

Preparation of well-dispersed gold/magnetite nanoparticles embedded on cellulose nanocrystals for efficient immobilization of Papain enzyme - Mahmoud, Khaled A.; Lam, Edmond; Hrapovic, Sabahudin; Luong, John H. T. (ACS Applied Materials & Interfaces, 2013)
A nanocomposite consisting of magnetite nanoparticles (Fe3O4NPs) and Au nanoparticles (AuNPs) embedded on cellulose nanocrystals (CNCs) was used as a magnetic support for the covalent conjugation of papain and facilitated recovery of this immobilized enzyme. Fe3O4NPs (10–20 nm in diameter) and AuNPs (3–7 nm in diameter) were stable and well-dispersed on the CNC surface. Energy-dispersive spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy were used to evaluate the surface composition and structure of CNC/Fe₃O₄NPs/AuNPs. The nanocomposite was successfully used for the immobilization and separation of papain from the reaction mixture. The optimal enzyme loading was 186 mg protein/g CNC/Fe₃O₄NPs/AuNPs, significantly higher than the value reported in the literature. The activity of immobilized papain was studied by electrochemical detection of its specific binding to the Thc-Fca-Gly-Gly-Tyr-Arg inhibitory sequence bound to an Au electrode. The immobilized enzyme retained 95% of its initial activity after 35 days of storage at 4 °C, compared to 41% for its free form counterpart.
Keywords: electrochemical detection; enzyme immobilization; gold nanoparticles; magnetite nanoparticles; papain

Joint photomicrobial process for the degradation of the insensitive munition N-Guanylurea-dinitramide (FOX-12) - Perreault, Nancy N.; Halasz, Annamaria; Thiboutot, Sonia; Ampleman, Guy; Hawari, Jalal (Environmental Science & Technology, 2013)
N-Guanylurea-dinitramide (FOX-12) is a very insensitive energetic material intended to be used in the composition of next-generation insensitive munitions. To help predict the environmental behavior and fate of FOX-12, we conducted a study to determine its photodegradability and biodegradability. When dissolved in water, FOX-12, a guanylurea-dinitramide salt, also named GUDN, dissociated instantly to produce the dinitramide moiety and guanylurea, as demonstrated by high-performance liquid chromatography (HPLC) analysis. When an aqueous solution of FOX-12 was subjected to photolysis using a solar-simulated photoreactor, we found a rapid removal of the dinitramide with concurrent formation of N₂O, NO₂⁻, and NO₃⁻. The second component, guanylurea, was photostable. However, when FOX-12 was incubated aerobically with the soil isolate Variovorax strain VC1 and protected from light, the dinitramide component of FOX-12 was recalcitrant but guanylurea degraded effectively to ammonia, guanidine, and presumably CO₂. When FOX-12 was incubated with strain VC1 in the presence of light, both components of FOX-12 degraded, giving similar products to those described above. We concluded that the new insensitive explosive FOX-12 can be effectively degraded by a joint photomicrobial process and, therefore, should not cause persistent contamination of surface waters.

A method for determining regioisomer abundances of polyunsaturated triacylglycerols in omega-3 enriched fish oils using reversed-phase liquid chromatography and triple-stage mass spectrometry - Cubero Herrera, Lisandra; Ramaley, Louis; Potvin, Michael A.; Melanson, Jeremy E. (Food Chemistry, 2013)
Reversed-phase high performance liquid chromatography (RP-HPLC), followed by post-column addition of lithium salts and electrospray ionisation triple-stage mass spectrometry (ESI-MS³) of lithiated TAG adducts, is shown to provide a useful method for the positional analysis of triacylglycerols (TAGs) in fish oils containing eicosapentaenoic (EPA, 20:5) and docosahexaenoic acids (DHA, 22:6). One prominent fragmentation pathway in the ESI-MS³ of these adduct ions involves the loss of a fatty acid from the sn-1/3 position in the first step followed by the loss of an α,β-unsaturated fatty acid from the sn-2 position in the second. Regioisomeric TAGs of the type ABA and AAB produced abundant product ions – [ABA + Li − RACOOH − R′BCHCHCOOH]+ and [AAB + Li − RACOOH − R′ACHCHCOOH]+ – the relative intensities of which were dependent on the position of acyl substituents. Standard solutions of TAGs containing different ratios of the regioisomeric pairs MME/MEM, PPE/PEP, PPD/PDP, EEP/EPE and DDP/DPD (M = 14:0, P = 16:0, E = 20:5, D = 22:6) were analysed by ESI-MS3 with a quadrupole linear ion trap instrument. Methodology developed on the standards was applied to quantifying the relative isomeric abundances of EPA and DHA in several fish oil samples. DHA was preferentially located at the sn-2 position in both DHA-containing TAGs studied, while EPA was either observed at near equal levels in all positions, or predominantly at the sn-1 and -3 positions in some cases. The analysis protocol allows for quantification of the designated regioisomers in one simple, rapid chromatographic procedure using a single column and has the advantage of specificity over other methods for the positional analysis of TAGs, since it eliminates interferences associated with co-eluting TAGs of the same molecular weight that yield isobaric diacylglycerol-like product ions.
Keywords: Triacylglycerols; Omega-3 fatty acids; Eicosapentaenoic acid; Docosahexaenoic acid; Fish oil; Multi-stage mass spectrometry; Regioisomer analysis

Nomoto indices for constant-depth zigzag manoeuvres of an autonomous underwater vehicle - Azarsina, Farhood; Williams, Christopher D. (ISRN Oceanography, 2013)
A two-dimensional simulation code is used to study the characteristics of constant-depth zigzag manoeuvres of the axisymmetric autonomous underwater vehicle (AUV) MUN Explorer. Sea trials data for several manoeuvres with the AUV have been reported during the past four years; however, to obtain a more complete understanding of the vehicle's hydrodynamics, additional towing tank tests and computer simulation were performed. The present work, based on the towing tank test results and sea-trials data, utilizes computer simulations to predict the performance of the MUN Explorer AUV during horizontal zigzag manoeuvres. Next, the Nomoto indices for this AUV during constant-depth zigzag manoeuvres are estimated using the simulation results, and, then, Nomoto's first-order model for the rate of turn of the vehicle during horizontal zigzag manoeuvres in response to a square-wave input for the rudder deflection angle is analytically solved. The paper investigates the validity of the simplified yaw equation to predict a zigzag manoeuvre. Results of this research are a first step to understand the details of zigzag manoeuvres of an AUV such as duration of the first execute, yaw-checking ability, and duration of the overshoot.

Genome-wide identification and characterization of microRNA genes and their targets in flax (Linum usitatissimum) - Barvkar, Vitthal T.; Pardeshi, Varsha C.; Kale, Sandip M.; Qiu, Shuqing; Rollins, Meaghen; Datla, Raju; Gupta, Vidya S.; Kadoo, Narendra Y. (Planta, 2013)
MicroRNAs (miRNAs) are small (20–24 nucleotide long) endogenous regulatory RNAs that play important roles in plant growth and development. They regulate gene expression at the post-transcriptional level by translational repression or target degradation and gene silencing. In this study, we identiﬁed 116 conserved miRNAs belonging to 23 families from the ﬂax (Linumusitatissimum L.) genome using a computational approach. The precursor miRNAs varied in length; while most of the mature miRNAs were 21 nucleotide long, intergenic and showed conserved signatures of RNA polymerase II transcripts in their upstream regions. Promoter region analysis of the ﬂax miRNA genes indicated prevalence of MYB transcription factor binding sites. Four miRNA gene clusters containing members of three phylogenetic groups were identiﬁed. Further, 142 target genes were predicted for these miRNAs and most of these represent transcriptional regulators. The miRNA encoding genes were expressed in diverse tissues as determined by digital expression analysis as well as real-time PCR. The expression of fourteen miRNAs and nine target genes was independently validated using the quantitative reverse transcription PCR (qRTPCR). This study suggests that a large number of conserved plant miRNAs are also found in ﬂax and these may play important roles in growth and development of ﬂax.
Keywords: Linseed; MiRNA; promoter analysis; digital expression analysis; gene cluster; MiRNA target transcript

Effect of simulated interior lifeboat environments on occupant thermal responses - Power, J. T.; Simões Ré, A. J. (Journal of Ocean Technology, 2013)
The effects of simulated interior lifeboat environments on the thermoregulatory responses of participants wearing immersion suits were investigated. Two different environmental conditions were investigated: the interior air temperature and relative humidity levels found in a conventional lifeboat that relies on passive ventilation (“Condition 1”); and those proposed to be in a next generation lifeboat that will have an active ventilation system (“Condition 2”). Participants performed three hour tests in both Condition 1 and Condition 2. Condition 1 produced a significantly greater increase (P < 0.05) in the rate of sweat accumulation, rate of mean skin temperature and gastro-intestinal temperature increase, heart rate, and physiological strain index values compared to Condition 2. Condition 1 caused an amount of sweat accumulation sufficient to dampen the underclothing to a level that would cause a significant reduction in predicted survival time. Heart rate, gastro-intestinal temperature and physiological strain index values continued to rise during Condition 1 suggesting that the level of thermal stress was uncompensable by the thermoregulatory systems of the participants which is supported by the air temperature and relative humidity levels being at a critical environmental limit in which heat balance cannot be achieved. It is concluded that the interior environmental conditions of conventional lifeboats that rely on a passive ventilation system will result in a level of thermal stress that cannot be compensated for by people wearing immersion suits which will result in increasing levels of physiological strain.

Comprehensive numerical simulations of a tanker collision with a bergy bit incorporating damage to the vessel - Gagnon, R. E.; Wang, J. (Ice Research for a Sustainable Environment, the 21st IAHR International Symposium on Ice, 2013)
Numerical simulations of a collision between a loaded tanker and a bergy bit have been conducted using LS-DynaTM software. The simulation incorporated hydrodynamics, via LSDyna’s ALE formulation, and a validated crushable foam ice model. The major portion of the vessel was treated as a rigid body and a section of the hull, located on the starboard side of the forward bow where the ice contact occurred, was modeled as typical ship grillage that could deform and sustain damage as a result of the collision. Strategies for dealing with the highly varying mesh densities needed for the simulation are discussed as well as load and pressure distribution throughout the course of the collision. Realistic movement of the bergy bit due to the vessel’s bow wave prior to contact with the ice was observed and the damage to the grillage in the initial stage of the collision resembled results from actual grillage damage tests in the lab. The collision eventually ruptured the hull in a ripping fashion resembling documented incidents.

A remote ice detection system suitable for marine and aerospace applications - Gagnon, R. E.; Groves, J.; Pearson, W. (Ice Research for a Sustainable Environment, the 21st IAHR International Symposium on Ice, 2013)
A new instrument for remote ice detection and thickness measurement is described. It incorporates two optically based technologies that give it capability to measure the thickness of clear or foggy layers of solid or liquid on surfaces. The prototype device, known as RIDE (Remote Ice Detection Equipment), is capable of measurements on moving surfaces such as wind turbines, and aircraft propellers and rotors. The current RIDE prototype is intended for relatively long distance measurements however a small, and much simpler, version of the technology is planned for short distance measurements (within a few meters). In the marine context a miniaturized version of the device could be utilized to regulate power for heating elements intended to deice walkways and stairways on vessels and structures. Similarly it could serve as a warning system to signal the encumbrance of safety and communications equipment. In the aerospace context a miniaturized device could measure and signal the need for mitigating strategies when icing accumulates on components of manned and drone-type aircraft. Details of the RIDE prototype, and miniaturization plans, are presented along with thickness data acquired during two test programs, one study on clear ice layers where measurements were obtained from a distance of ~ 15 m and the other on foggy ice layers at a distance of approximately 13 m.

Response of IACS URI ship structures to real-time full-scale operational ice loads - Quinton, Bruce W. T.; Daley, Claude G.; Gagnon, Robert E. ((ICETECH 2012) International Conference and Exhibition on Performance of Ships and Structures in Ice, 2013)
Moving ice loads can incite significantly different structural responses in a steel grillage structure than can stationary ice loads. This is significant because the accepted standard for the design and analysis of ice-classed ship structures is to assume a stationary ice load (IACS URI I2.3.1). The following work utilizes the 4D Pressure Method ((Quinton, Daley, and Gagnon 2012)) to apply thirty-five of the most significant ice loads recorded during the USCGC Polar Sea trials (1982-86), to fourteen IACS URI PC1-7 classed grillages; using explicit finite element analyses. Two grillage variations for each of the seven PC classes were examined: grillages with "built T" framing and grillages with "flatbar" framing. In short, the following simulations directly employ real-time/real-space measured full-scale ice loads, and thus provide insight into the structural capabilities of the various IACS URI polar classes when subject to actual (moving) ice loads.
Keywords: Polar Sea; polar class; moving load; ice; 4D Pressure Method

Tubular daylighting devices. Part I: development of an optical model (1415-RP) - Laouadi, Abdelaziz; Galasiu, Anca D.; Saber, Hamed H.; Arsenault, Chantal (HVAC and R Research, 2013)
Tubular daylighting devices are systems that collect and channel daylight from building roofs into deep interior spaces. To meet high standards of building energy efficiency and glare-free indoor environments, tubular daylighting device technologies have been rapidly and continuously evolving over the past two decades. However, this pace has been counteracted by a lack of reliable computer design tools. This article presents the development of analytical models to compute the optical characteristics (transmittance, reflectance, and layer absorptances) of various types of complex tubular daylighting devices New metrics for the optical and lighting performance are developed. The optical models are based on the ray-tracing technique, and account for the spectral (monochromatic) or broad-band optical properties of tubular daylighting device glazing panes. Experimental validation of these models is presented in an accompanying paper.
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Keywords: Tubular daylighting device; lightpipe; skylight; optical model

The zero-peak house: full-scale experiments and demonstration - Newsham, Guy R.; Galasiu, Anca D.; Armstrong, Marianne M.; Beausoleil-Morrison, Ian; Szadkowski, Frank; Sager, Jeremy M.; Pietila, Andrea J.; Rowlands, Ian H. (Energy and Buildings, 2013)
Houses represent a substantial fraction of the summer peak electrical load, and therefore measures to reduce peak demand at the household level may be valuable in stabilizing the grid and lowering peak costs. We conducted studies in geometrically-identical, side-by-side full-scale detached houses. One house was operated in a conventional manner and provided a typical reference case. In the other house we applied a variety of measures designed to reduce or shift load from peak periods. Our results demonstrated that a combination of practical operational modifications (air-conditioner cycling, doing laundry later in the evening) and commercially-available technology (exterior shading, modest PV array, energy-efficient lighting) was able to dramatically reduce (in some cases to zero) the peak electrical demand from the grid on the hottest days of the year.
Keywords: residential; demande response; summer; electricity; peak demand; Canada; house; shading; air conditioning; PV

A model of residential energy end-use in Canada: using conditional demand analysis to suggest policy options for community energy planners - Newsham, Guy R.; Donnelly, Cara L. (Energy Policy, 2013)
We applied conditional demand analysis (CDA) to estimate the average annual energy use of various electrical and natural gas appliances, and derived energy reductions associated with certain appliance upgrades and behaviours. The raw data came from 9773 Canadian households, and comprised annual electricity and natural gas use, and responses to >600 questions on dwelling and occupant characteristics, appliances, heating and cooling equipment, and associated behaviours. Replacing an old (>10 years) refrigerator with a new one was estimated to save 100 kW h/year; replacing an incandescent lamp with a CFL/LED lamp was estimated to save 20 kW h/year; and upgrading an old central heating system with a new one was estimated to save 2000 kW h/year. This latter effect was similar to that of reducing the number of walls exposed to the outside. Reducing the winter thermostat setpoint during occupied, waking hours was estimated to lower annual energy use by 200 kW h/°C-reduction, and lowering the thermostat setting overnight in winter relative to the setting during waking hours (night-time setback) was estimated to have a similar effect. This information may be used by policy-makers to optimize incentive programs, information campaigns, or other energy use change instruments.
Keywords: Residential; design; retrofit; appliances

Tubular daylighting devices. Part II: validation of the optical model (1415-RP) - Laouadi, Abdelaziz; Arsenault, Chantal; Saber, Hamed H.; Galasiu, Anca D. (HVAC and R Research, 2013)
This article presents the development of a methodology to measure the visible transmittance of complex configurations of tubular daylighting devices under direct sunlight, and conducts a comparison study between the measurements and computer simulations using the new optical model developed in the first part of the study. A large integrating box was built and calibrated, and the procedure was benchmarked by comparing the measurement of a transparent glazing sample with the manufacturer data. Two commercially available tubular daylighting devices with prismatic and frosted elements built into the glazing and a custom-made tubular daylighting device with a complex pipe having roof and ceiling elbows were selected for the comparison study. The model predictions were overall in good agreement with the measurement for the tested tubular daylighting device configurations, and the sources of discrepancies were clearly identified.
Keywords: Tubular daylighting; tubular skylight; lightpipe; skylight; light guide; optical model

Optical model for tubular hollow light guides (1415-RP) - Laouadi, Abdelaziz; Saber, Hamed H.; Galasiu, Anca D.; Arsenault, Chantal (HVAC and R Research, 2013)
Tubular hollow light guides are found in many lighting and daylighting systems to transport collected light into deep spaces of building interiors. Linear straight guides are popularly used due to their high optical efficiency, but non-linear guides with bent sections are sometimes required to fulfill some installation restrictions. The optical performance of such bent guides is, however, unknown. This article presents the development, validation, and application of an optical model to compute the transmittance of light guides with and without bends. The model is based on the ray-tracing technique and can handle segmented guides with connection elbows. Measurement of the light transmittance of a light guide with two connection elbows is conducted using an outdoor large integrating box to benchmark the model. The model predictions are in good agreement with the measurement and public data for vertical light guides without bends. The model predictions for bent light guides installed in a northern mid-latitude location show that orienting the middle pipe section of the guide toward the northern direction results in better control of sunlight and solar heat gains than other orientations.
Keywords: Light guide; tubular daylighting device; skylight; lightpipe; optical model

Tubular daylighting devices: development and validation of a thermal model (1415-RP) - Laouadi, Abdelaziz; Saber, Hamed H.; Galasiu, Anca D.; Arsenault, Chantal (HVAC and R Research, 2013)
This article presents the development and validation of a simplified model to compute the thermal characteristics (solar heat gain coefficient and thermal conductance (U-factor)) and surface temperatures of tubular daylighting devices. The model takes into account the three modes of heat transfer: conduction, convection, and surface-to-surface radiation. A one-dimensional heat conduction model is applied to tubular daylight device glazing layers. The convective heat transfer from tubular daylight device surfaces to their adjacent air spaces uses existing correlations for natural flows in enclosed air cavities and free stream air spaces. A zonal model, in which the pipe air space is divided into a number of thermally stacked zones, is used to predict the vertical average temperature distribution in the air cavity and wall surface of pipe. Thermal radiation exchange among surfaces uses the formulation of the form factor applied to the aforementioned zonal model. An iterative sequential procedure is proposed to solve the temperature distribution in tubular daylight device glazing layers and air cavities. The U-factor predictions of the simplified model are compared with the National Fenestration Rating Council certified product rating measurement data and detailed computational fluid dynamic simulations. Four tubular daylight device products are simulated under the National Fenestration Rating Council standard rating conditions for the residential (insulation at ceiling level) and commercial (insulation at roof level) settings. The temperatures of the tubular daylight device glazing layers and vertical temperature distribution inside the pipe air space are also compared with the computational fluid dynamic simulations. The results show that the U-factor predictions of the simplified model are in good agreement with the measurement data and computational fluid dynamic simulations, within a maximum deviation of 15% for both the residential and commercial rating conditions.
Keywords: Tubular daylighting device; lightpipe; skylight; thermal model

Application of hybrid micro-cogeneration system: thermal and power energy solutions for Canadian residences - Entchev, E.; Yang, L.; Szadkowski, F.; Armstrong, M.; Swinton, M. (Energy and Buildings, 2013)
This paper presents results from a field trial with a hybrid micro-cogeneration system applied to satisfy both thermal and power needs of a typical Canadian detached house. The hybrid system consists of an internal combustion engine integrated with a high efficiency furnace. It was installed, integrated with the rest of the mechanical systems and demonstrated at the Canadian Center for Housing Technology (CCHT). Cost analysis was performed to examine the economics of such systems in relation to different price structures imposed by the electric utilities. The study revealed that the hybrid micro-cogeneration system performed reliably and generated both heat and power with high efficiency during the heating season and was able to satisfy the heating demand under very cold weather conditions. The power generated by the system was first directed to the house satisfying 50% of the electric load with the other 50% being exported to the grid. The project demonstrated that micro-cogeneration systems when sized to meet the base electric load and design thermal load of the residence are a valuable alternative to the central power generation plants and are able to reliably satisfy the house thermal/power demand even under extreme cold conditions.
Keywords: Hybrid micro-cogeneration system; Micro CHP; Internal combustion engine; High efficiency furnace; Load profiles; Control strategies

Do ‘green’ buildings have better indoor environments? New evidence - Newsham, Guy R.; Birt, Benjamin J.; Arsenault, Chantal; Thompson, Alexandra J. L.; Veitch, Jennifer A.; Mancini, Sandra; Galasiu, Anca D.; Gover, Bradford (Brad); Macdonald, Iain A.; Burns, Gregory J. (Building Research and Information, 2013)
A post-occupancy evaluation (POE) of 12 green and 12 conventional office buildings across Canada and the northern United States was conducted. Occupants (N = 2545) completed an online questionnaire related to environmental satisfaction, job satisfaction and organizational commitment, health and well-being, environmental attitudes, and commuting. In each building on-site physical measurements at a sample of workstations (N= 974) were taken, including: thermal conditions, air quality, acoustics, lighting, workstation size, ceiling height, window access and shading, and surface finishes. Green buildings exhibited superior performance compared with similar conventional buildings. Better outcomes included: environmental satisfaction, satisfaction with thermal conditions, satisfaction with the view to the outside, aesthetic appearance, less disturbance from heating, ventilation and air-conditioning (HVAC) noise, workplace image, night-time sleep quality, mood, physical symptoms, and reduced number of airborne particulates. A variety of physical features led to improved occupant outcomes across all buildings, including: conditions associated with speech privacy, lower background noise levels, higher light levels, greater access to windows, conditions associated with thermal comfort, and fewer airborne particulates. Green building rating systems might benefit from further attention in several areas, including: credits related to acoustic performance, a greater focus on reducing airborne particulates, enhanced support for the interdisciplinary design process and development of POE protocols.
Keywords: Building performance; Environmental assessment; Green buildings; Indoor environment; Leadership in Energy and Environmental Design (LEED); Occupant satisfaction; Post-occupation evaluation; Performances des bâtiments; Bilan environnemental; Bâtiments verts; Environnement intérieur; Leadership in Energy and Environmental Design (LEED); Satisfaction des occupants; Evaluation après occupation

Failure analysis in energy related materials and coatings - role of nanostructured materials for sustainable solutions - Bensebaa, Farid; Govil, J. N. (Nanotechnology Vol. 6: Energy and Environment, 2013)
Improving performance and lifetime cost of current base materials and coating solutions requires detailed failure analysis. Materials corrosion has significant financial, environmental and safety impacts in the petrochemical and transportation sectors. Alternative materials have been recently developed to improve performance over cost ratio. Nanomaterials are introduced at even increased pace within components in numerous industrial sectors. In few cases, nanostructured materials and films improve the performance over cost ratio while reducing utilization of raw materials and environmental impact. In most cases, detailed failure analysis is important to quantify advantages and shortcomings of nanomaterials. In particular, detailed and complementary materials science and materials engineering investigation is recommended. This will allow better understanding of the relationship between the composition and structure in one hand and functional properties on the other hand.
Keywords: Failure analysis; Nondestructive testing; Corrosion; Nanomaterials; Coating

Effect of dietary inclusion of Atlantic snow crab, Chionoecetes opilio and Northern pink shrimp, Pandalis borealis processing by-products on nutrient digestibility by juvenile haddock, Melanogrammus aeglefinus L. - Tibbetts, Sean M.; Lall, Santosh P. (Animal Feed Science and Technology, 2013)
A study was conducted to evaluate the effect of dietary inclusion of Atlantic snow crab, Chionoecetes opilio (Crab) and Northern pink shrimp, Pandalis borealis (Shrimp) by-product meals on nutrient digestibility in haddock, Melanogrammus aeglefinus. The study provides coefficients of total tract apparent digestibility (CTTADs) essential for diet formulations aimed at further growth performance and nutrient utilization studies with gadoids using these waste streams as potential replacements for high-cost fish meals and poorly digestible wheat by-products. Organic matter (OM) CTTAD was significantly improved (P=0.005) with Shrimp150 (0.82) relative to the Control (0.79), while Shrimp300 was similar (0.79) (P=1.000). No significant difference in OM CTTAD was found between the Control and Crab150 (P=0.110), Shrimp150 (P=0.473) or Shrimp300 (P=0.144) at an average of 0.80. However, OM CTTAD was significantly reduced (P<0.001) for Crab300 (0.76). Inclusion of Shrimp at 150 g/kg significantly improved (P=0.003) gross energy (GE) CTTAD (0.85 on average) relative to the Control (0.83), while Crab150 (P=0.081), Crab300 (P=0.134) and Shrimp300 (P=0.986) were statistically equal to the Control (average, 0.82). Crude protein (CP) CTTAD of Crab150 (P=0.803) and Shrimp150 (P=0.980) were similar to the Control at an average of 0.90 while Crab300 (P<0.001) and Shrimp300 (P=0.005) were significantly reduced (average 0.86). Dietary inclusion of either Atlantic snow crab or Northern pink shrimp processing by-product meal at 150 g/kg, concomitant with a 50% reduction in wheat middlings and 10% reduction in fish meal, resulted in OM, GE and CP CTTADs equal to or exceeding that of the fish meal-based Control diet.
Keywords: Haddock; Gadoid; crab; shrimp; nutrient digestibility

Transcriptome analysis of bitter acid biosynthesis and precursor pathways in hop (Humulus lupulus) - Clark, Shawn M.; Vaitheeswaran, Vinidhra; Ambrose, Stephen J.; Purves, Randy W.; Page, Jonathan E. (BMC Plant Biology, 2013)
Background: Bitter acids (e.g. humulone) are prenylated polyketides synthesized in lupulin glands of the hop plant (Humulus lupulus) which are important contributors to the bitter flavour and stability of beer. Bitter acids are formed from acyl-CoA precursors derived from branched-chain amino acid (BCAA) degradation and C5 prenyl diphosphates from the methyl-D-erythritol 4-phosphate (MEP) pathway. We used RNA sequencing (RNA-seq) to obtain the transcriptomes of isolated lupulin glands, cones with glands removed and leaves from high α-acid hop cultivars, and analyzed these datasets for genes involved in bitter acid biosynthesis including the supply of major precursors. We also measured the levels of BCAAs, acyl-CoA intermediates, and bitter acids in glands, cones and leaves.Results: Transcripts encoding all the enzymes of BCAA metabolism were significantly more abundant in lupulin glands, indicating that BCAA biosynthesis and subsequent degradation occurs in these specialized cells. Branched-chain acyl-CoAs and bitter acids were present at higher levels in glands compared with leaves and cones. RNA-seq analysis showed the gland-specific expression of the MEP pathway, enzymes of sucrose degradation and several transcription factors that may regulate bitter acid biosynthesis in glands. Two branched-chain aminotransferase (BCAT) enzymes, HlBCAT1 and HlBCAT2, were abundant, with gene expression quantification by RNA-seq and qRT-PCR indicating that HlBCAT1 was specific to glands while HlBCAT2 was present in glands, cones and leaves. Recombinant HlBCAT1 and HlBCAT2 catalyzed forward (biosynthetic) and reverse (catabolic) reactions with similar kinetic parameters. HlBCAT1 is targeted to mitochondria where it likely plays a role in BCAA catabolism. HlBCAT2 is a plastidial enzyme likely involved in BCAA biosynthesis. Phylogenetic analysis of the hop BCATs and those from other plants showed that they group into distinct biosynthetic (plastidial) and catabolic (mitochondrial) clades.Conclusions: Our analysis of the hop transcriptome significantly expands the genomic resources available for this agriculturally-important crop. This study provides evidence for the lupulin gland-specific biosynthesis of BCAAs and prenyl diphosphates to provide precursors for the production of bitter acids. The biosynthetic pathway leading to BCAAs in lupulin glands involves the plastidial enzyme, HlBCAT2. The mitochondrial enzyme HlBCAT1 degrades BCAAs as the first step in the catabolic pathway leading to branched chain-acyl-CoAs.
Keywords: Humulus; Humulus lupulus

Higher-capacity lithium ion battery chemistries for improved residential energy storage with micro-cogeneration - Darcovich, K.; Henquin, E. R.; Kenney, B.; Davidson, I. J.; Saldanha, N.; Beausoleil-Morrison, I. (Applied Energy, 2013)
Combined heat and power on a residential scale, also known as micro-cogeneration, is currently gaining traction as an energy savings practice. The configuration of micro-cogeneration systems is highly variable, as local climate, energy supply, energy market and the feasibility of including renewable type components such as wind turbines or photovoltaic panels are all factors. Large-scale lithium ion batteries for electrical storage in this context can provide cost savings, operational flexibility, and reduced stress on the distribution grid as well as a degree of contingency for installations relying upon unsteady renewables. Concurrently, significant advances in component materials used to make lithium ion cells offer performance improvements in terms of power output, energy capacity, robustness and longevity, thereby enhancing their prospective utility in residential micro-cogeneration installations. The present study evaluates annual residential energy use for a typical Canadian home connected to the electrical grid, equipped with a micro-cogeneration system consisting of a Stirling engine for supplying heat and power, coupled with a nominal 2 kW/6 kW h lithium ion battery. Two novel battery cathode chemistries, one a new Li–NCA material, the other a high voltage Ni-doped lithium manganate, are compared in the residential micro-cogeneration context with a system equipped with the presently conventional LiMn2O4 spinel-type battery
Keywords: Building simulation; Lithium ion battery; High capacity cathode; Battery pack; Residential micro-cogeneration

Alteration of microbial community structure affects diesel biodegradation in an Arctic soil - Bell, Terrence H.; Yergeau, Etienne; Juck, Dave F.; Whyte, Lyle G.; Greer, Charles W. (FEMS Microbiology Ecology, 2013)
A wide range of microbial taxa are active in hydrocarbon-contaminated Arctic soils, and many are capable of hydrocarbon metabolism. The most effective hydrocarbon degraders may not naturally dominate following contamination events, so shifts in microbial abundance could potentially increase hydrocarbon biodegradation. In this study, we contaminated an Arctic soil with diesel and used gentamicin and vancomycin to inhibit distinct portions of the microbial community. We measured diesel loss using gas chromatography, bacterial and fungal abundance with qPCR, and assessed bacterial diversity and community composition through Ion Torrent sequencing of 16S rRNA gene amplicons. The combined addition of both antibiotics increased diesel biodegradation significantly relative to the no-antibiotic treatment, despite reduced bacterial and fungal abundance; however, this effect was not observed when nutrients were also added. All treatments produced unique bacterial communities, and both Xanthomonadaceae and Micrococcineae were dominant in the dual antibiotic treatment. The bacterial communities resulting from dual gentamicin and vancomycin addition were similar both with and without nutrients, although nutrient addition produced a much larger fungal population, which may partly explain the differences in biodegradation between these two treatments. These results suggest that the most efficient hydrocarbon-degrading community may not always be promoted naturally in contaminated soils.
Keywords: community composition; Arctic; bioremediation; hydrocarbons; Ion Torrent; soil microorganisms

Durable sulfonated poly(arylene sulfide sulfone nitrile)s containing naphthalene units for direct methanol fuel cells (DMFCs) - Shin, Dong Won; Lee, So Young; Kang, Na Rae; Lee, Kang Hyuck; Guiver, Michael D.; Lee, Young Moo (Macromolecules, 2013)
Sulfonated poly(arylene sulfide sulfone nitrile)s (SN) were synthesized to investigate the effects of naphthalene units in the polymer backbone on membrane properties. The small and planar naphthalene in the main chain induced semi-crystallinity in the polymer, as confirmed by molecular simulations and wide angle X-ray diffraction patters. The semi-crystalline SN polymer membranes exhibited excellent chemical and mechanical properties, better than those of their phenylene counterpart (SP). In particular, the water uptake and swelling ration of the SN membranes were much lower than those of the SP membranes. Furthermore, the SN membranes exhibited a greatly reduced methanol permeability (9-17 x 10(-8) cm(sq) s(-1)) compared to Nafion 212(330 x 10(-8) cm(sq) s(-1)) at 30 degrees Celsius in 10 M methanol. Moreover, sulfide- and naphthalene-based chemical structure and semi-crystalline nature of hte SN membranes enhanced their DMFC single cell performance and long-term stability during fuel cell operation.
Keywords: direct methanol fuel cell (DMFC); proton exchange membrane (PEM); sulfonated poly(arylene sulfide sulfone nitrile); naphthalene units

Naphthalene-based poly(arylene ether ketone) anion exchange membranes - Liu, Zhuang; Li, Xiaobai; Shen, Kunzhi; Feng, Pengju; Zhang, Yinan; Xu, Xu; Hu, Wei; Jiang, Zhenhua; Liu, Baijun; Guiver, Michael D. (Journal of Materials Chemistry A, 2013)
Naphthalene-based poly(arylene ether ketone)s were obtained through a three-step process involving polymerization of methylated polymers, followed by bromination and derivitization with a diquaternary-ammonium group. The ionic conductivities of the anion exchange membranes were above 10(-2) S cm(-1) at room temperature and the membrane with an IEC = 1.46 mequic. g(-1) attained an ion conductivity of 7.4 x 10(-2) S cm(-1) at 100 degrees Celsius, which is higher than many reported results. The membrane series had low water uptake and excellent dimensional stability, even at the highest IEC values. In addition, the membranes were insoluble in organic solvents and concentrated alkaline solutions for many days, even under heating, suggesting their excellent stability. These combined data suggest that the membranes have potential to be used as anion exchange membranes for fuel cell applications.

Polyethylene-based radiation grafted anion-exchange membranes for alkaline fuel cells - Sherazi, Tauqir A.; Sohn, Joon Yong; Lee, Young Moo; Guiver, Michael D. (Journal of Membrane Science, 2013)
Vinyl benzyl chloride was grafted onto ultra-high molecular weight polyethylene powder (UHMWPE) by radiation grafting. The grafted powder was subsequently fabricated into membrane by melt pressing. The effect of absorbed radiation dose on the degree of grafting (DG) is discussed. The melt-flow properties of PVBC grafted PE with low degree of grafting was conducive to forming homogeneous pore-free membranes, which was confirmed by scanning electron microscopic analysis. The grafted polytheylene membranes were post functionalized with trimethylamine, followed by alkalization to obtain anion-exchange membranes (AEMs). The structures of the resulting AEMs were characterized by Fourier transform infrared spectroscopy, which showed that the grafted membranes were successfully functionalized. The properties of the AEMs, including ion exchange capacity, water uptake, in-plane swelling, methanol uptake, methanol permeability, and hydroxide ion conductivity were investigated. The AEMs showed reasonably good chemical stability, as evidenced by the ion exchange capacity being maintained for a ong duration, even in highly alkaline conditions. The membranes exhibited a maximum ionic conductivity of 47.5 mS cm(-1) at 90 degrees Celsius (30 mS cm(-1) at 60 degrees Celsius). Methanol permeability was found to be in the order of 10(-8) cm(sq) s(-1), which is considerably lower than that of Nafion (registered). The membranes have useful properties consistent with anion exchange membranese suitable for alkaline fuel cells.
Keywords: Anion exchange membrane; Radiation grafting; Polyethylene; UHMWPE; Vinylbenzylchloride; Trimethylamine

A capillary water retention effect to improve medium-temperature fuel cell performance - Lee, So Young; Shin, Dong Won; Wang, Chenyi; Lee, Kang Hyuck; Guiver, Michael D.; Lee, Young Moo (Electrochemistry Communications, 2013)
We demonstrate that small and narrow hydrophilic conducting morphology in sulfonated aromatic membranes leads to much better fuel cell performance at medium temperature and low humidity conditions than those with larger hydrophilic domains. A comparison of three types of sulfonated poly(arylene ether sulfone)s (SPAES) with random, block, and graft architecture indicates that small hydrophilic domain sizes (less than 5 nm) appear to be important in supporting water retention under low relative humidity (RH) conditions intended for medium temperature (less than 100 degrees Celsius) fuel cell applications. The graft copolymer outperformed both a random copolymer and multiblock copolymer at 120 degrees Celsius and 35% RH fuel cell operating conditions due to capillary condensation of water within the 3-5 nm hydrophilic domains.
Keywords: Fuel cell; Polymer electrolyte membrane; Medium-temperature; Sulfonated poly(arylene ether sulfone); Morphology

Polymer rigidity improves microporous membranes - Guiver, Michael D.; Lee, Young Moo (Science, 2013)
Microporous membranes with rigid polymer chains have high gas permeability but can separate gas molecules of slightly different sizes.

The electrochemistry of metallic nickel: oxides, hydroxides, hydrides and alkaline hydrogen evolution - Hall, David S.; Bock, Christina; Macdougall, Barry R. (Journal of the Electrochemical Society, 2013)
Ni-based catalysts in aqueous alkaline media are low-cost electrode materials for electrolytic hydrogen generation, a renewable method of producing fuel and industrial feedstock. However, Ni cathodes show a significant decrease in their hydrogen evolution reaction (HER) activity after several hours of electrolysis. Further, industrial electrolysers are often subjected to transient anodic currents, the effects of which on Ni-based catalysts are not well-known. We consider the source of electrode deactivation and the effects of temporary anodic currents on smooth metallic Ni electrodes in alkaline solutions by cyclic voltammetry (CV), galvanostatic and potentiostatic polarization, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Polished surfaces are covered by a bilayer composed of α-Ni(OH)2 underlaid by non-stoichiometric NiOx. Below the reversible hydrogen electrode (RHE) potential, the air-formed layer mostly reduces to Ni metal and H atoms incorporate deep into the electrode material. Under industrial conditions, i.e., concentrated NaOH/KOH solutions and large cathodic current densities, α-NiHx and β-NiHx can form at the electrode surface. Above the RHE potential, NiOx, α-Ni(OH)2, β-Ni(OH)2 and β-NiOOH form reversibly and mostly reduce back to Ni on subsequent cathodic polarization. However, repeated oxidation and reduction will introduce strain on a catalyst material, which may lead to its mechanical failure.

Compositional and morphological changes for ordered PtxFey/CO2 electro-reduction catalysts - Chen, Liang; Chan, Mickey C. Y.; Nan, Feihong; Bock, Christina; Botton, Gianluigi A.; Mercier, Patrick H. J.; Macdougall, Barry R. (ChemCatChem, 2013)
Changes in O2 reduction activity (orr) and structural changes of carbon supported catalysts upon electrochemical stress testing are investigated. Focus is placed on two alloy catalysts of nominal Pt3Fe/C and Pt3Fe2/C compositions. Energy dispersive X-ray Spectroscopy (EDXS) spot and line analyses reveal a dependence of the Fe composition on the particle size particularly for he two as-prepared catalysts. Catalyst particles are shown to exist of a Pt enriched shell and a PtxFey alloy core. Larger (larger ca. 10 nm) particles are shown to have a higher Fe content that approaches the nominal composition suggesting that the smaller (smaller than 6 nm) Pt catalyst particles are more difficult to alloy. HAADF-STEM, XRD, and scanning electron microscope (SEM) with EDXS show that Fe is gradually lost from the catalyst particles as a result of extensive potential (E)-cycling. Changes upon E-cycling are most clearly observed for the small (smaller than 3 nm) particles, for which, Fe is almost entirely depleted. However, the catalytic orr activities remain constant over an extensive cycling period for the PtxFey/C catalysts. In fact, the mass orr activities are seen to decrease proportionally with the Pt surface area (Apt). The histograms before and after cycling are compared to observed changes in APt, and are also discussed in comparison to E-holding experiments. It is concluded that the dissolution of Pt is a strong contributor for the observed drop in APt and mass orr activity for the PtxFey/C catalysts. The continuous transition between Pt-oxide formation and its reduction to Pt metal is suggested to play a major role for the degradation of the PtxFey/C catalysts studied in this work.
Keywords: O2 reduction catalysts; Lifetime; PEMFC; HAADF-STEM; EDX spot and line analyses

High-quality reference genes for quantifying the transcriptional responses of Oryza sativa L. (ssp. indica and japonica) to abiotic stress conditions - Maksup, Sarunyaporn; Supaibulwatana, Kanyaratt; Selvaraj, Gopalan (Chinese Science Bulletin, 2013)
Rice (Oryza sativa L.) is important to food security and is also an excellent model plant for numerous cereal crops. A functional genomics study in rice includes characterization of the expression dynamics of genes by quantitative real-time PCR (qPCR) analysis; this is a significant key for developing rice varieties that perform well in the face of adverse climate change. The qPCR analysis requires the use of appropriate reference genes in order to make any quantitative interpretations meaningful. Here, the new potential reference genes were selected from a huge public database of rice microarray experiments. The expression stability of 14 candidates and 4 conventional reference genes was validated by geNorm PLUS and NormFinder software. Seven candidates are superior to the conventionally used reference genes in qPCR and three genes can be used reliably for quantitating the expression of genes involved in abiotic stress responses. These high-quality references EP (LOC_Os05g08980), HNR (LOC_Os01g71770), and TBC (LOC_Os09g34040) worked very well in three indica genotypes and one japonica genotype. One of indica genotypes including the Jasmine rice, KDML105 developed in Thailand for which no reference genes have been reported until now.
Keywords: KDML105; microarrays; quantitative real-time PCR; reference gene; rice (Oryza sativa L.); stress responsive gene

Characterization of carrier states in CuWO4 thin-films at elevated temperatures using conductometric analysis - Gonzalez, Carlos M.; Dunford, Jeffrey L.; Du, Xiaomei; Post, Michael L. (Journal of Solid State Chemistry, 2013)
CuWO4 thin-films were deposited by pulsed laser deposition onto an insulating substrate. The temperature dependence of the electronic conductivity of CuWO4 thin-films was determed over the 100-500 degree Celsius temperature range in a synthetic air atmosphere. Additionally, variations of conductivity at 300 degrees Celsius and 500 degrees Celsius have been measured for oxygen partial pressures (0.1 atm less than p(O2) less than 0.9 atm) in nitrogen. The apparent activation energy (delta)Ea for the electrical conduction has been estimated. The study of the temperature effect on the electron transport properties of CuWO4 thin-films reveals the operation of two temperature-dependent oxygen states. The effect of varying oxygen concentration on the electronic properties is discussed in detail. The electrochemical nature of the operating oxygen states for the 100-500 degree Celsius temperature range is deduced using a physicochemical model that relates electronic conductivity with oxygen partial pressure and temperature.
Keywords: Semiconducting metal-oxide; Surface characterization; Electron transport; Conductometric analysis; Activation energy; Oxygen states

Membrane electrode assemblies based on hydrocarbon electrolytes with nitrile groups for direct methanol fuel cells - Hurter, Stephan; Muller, Martin; Wippermann, Klaus; Guiver, Michael D.; Scoles, Ludmilla; Stolten, Detlef (ECS Transactions, 2013)
Sulfonated poly(aryl ether ether nitrile)s - sPAEEN are promising materials for reducing the methanol permeation from anode to cathode due to the strong polar interchain interactions caused by the nitrile functional groups. This feature allows the preparation of membranes with high proton conductivities and low crossover of methanol and water. Despite similar specific conductivities and lower thickness of the hydrocarbon membranes compared to Nafion 115, HC-MEAs prepared by a classic hot-pressing step show 40-70 % higher values for the cell resistances compared to Nafion 115 based MEAs. Therefore the MEA preparation procedure was changed to reduce losses due to poor lamination between the Nafion-based GDE and the hydrocarbon membrane. The impact of the type of sPAEEN membrane and the MEA preparation together with the cell performance data will be compared with state-of-the art Nafion-based cells and discussed in terms of consequences for the operating conditions for a DMFC system.

Strain fields around dislocation arrays in a Σ9 silicon bicrystal measured by scanning transmission electron microscopy - Couillard, Martin; Radtke, Guillaume; Botton, Gianluigi A. (Philosophical Magazine, 2013)
Strain fields around grain boundary dislocations are measured by applying geometric phase analysis on atomic resolution images obtained from multiple fast acquisitions in scanning transmission electron microscopy. Maps of lattice distortions in silicon introduced by an array of pure edge dislocations located at a Σ9(122) grain boundary are compared with the predictions from isotropic elastic theory, and the atomic structure of dislocation cores is deduced from images displaying all the atomic columns. For strain measurements, reducing the acquisition time is found to significantly decrease the effects of instabilities on the high-resolution images. Contributions from scanning artefacts are also diminished by summing multiple images following a cross-correlation alignment procedure. Combined with the sub-Ångström resolution obtained with an aberration corrector, and the stable dedicated microscope’s environment, therapid acquisition method provides the measurements of atomic displacements with accuracy below 10 pm. Finally, the advantages of combining strain measurements with the collection of various analytical signals in a scanning transmission electron microscope are discussed.

Contribution to the crystallography of hydrotalcites: the crystal structures of woodallite and takovite - Mills, Stuart J.; Whitfield, Pamela S.; Kampf, Anthony R.; Wilson, Siobhan A.; Dipple, Gregory M.; Raudsepp, Mati; Favreau, Georges (Journal of GEOsciences, 2013)
The crystal structures of the 3R polytypes of takovite and woodallite are presented. The structure of takovite was solved on a single crystal from the Agoudal mine, Bou Azzer district, Tazenakht, Morocco to R1 = 1.87 % for 94 unique reflections [Fo>4σF] in R-3m, with unit cell parameters a = 3.0290(2) and c = 22.5995(15) Å. The crystal structure of woodallite [space group R-3m, with unit cell parameters a = 3.10124(8) and c = 23.6817(16) Å] was refined utilising the Rietveld method on a sample from the MKD5 orebody at the Mount Keith Nickel Mine, Western Australia.
Keywords: Hydrotalcite; Layered double hydroxide; Takovite; Woodallite; Crystal structure; Rietveld refinement

The Two-step biosynthesis of cyclic peptides from linear precursors in a member of the plant family Caryophyllaceae involves cyclization by a Serine Protease-like enzyme - Barber, Carla J. S.; Pujara, Pareshkumar T.; Reed, Darwin W.; Chiwocha, Shiela; Zhang, Haixia; Covello, Patrick S. (Journal of Biological Chemistry, 2013)
Background: In the Caryophyllaceae, cyclic peptides (CP) are biosynthesized from linear precursors via an unknown pathway. Results: Two protease-like enzymes are involved in precursor processing. Conclusion: A serine protease-like enzyme was recruited for the cyclization step in CP biosynthesis. Significance: This represents a very significant advance in our understanding of the mode and evolution of CP biosynthesis in plants. Caryophyllaceae-type cyclic peptides (CPs) of 5–12 proteinogenic amino acids occur in 10 plant families. In Saponaria vaccaria (Caryophyllaceae), they have been shown to be formed from linear peptide precursors derived from ribosomal translation. There is also evidence for such precursors in other members of the Caryophyllaceae, Rutaceae, and Linaceae families. The biosynthesis of CP in the developing seeds of S. vaccaria was investigated with respect to the enzymes involved in precursor processing. Through biochemical assays with seed extracts and synthetic peptides, an enzyme named oligopeptidase 1 (OLP1) was found that catalyzes the cleavage of intermediates at the N terminus of the incipient CP. A second enzyme, peptide cyclase 1 (PCY1), which was separated chromatographically from OLP1, was found to act on the product of OLP1, giving rise to a cyclic peptide and concomitant removal of a C-terminal flanking sequence. PCY1 was partially purified, and using the methods of proteomics, a full-length cDNA clone encoding an enzyme matching the properties of PCY1 was obtained. The substrate specificity of purified recombinant PCY1, believed to be the first cloned plant enzyme whose function is peptide cyclization, was tested with synthetic peptides. The results are discussed in the light of CP biosynthetic systems of other organisms.
Keywords: Peptidases; peptide biosythesis; plant biochemsitry; plant molecular biology; protease; Caryophyllaceae; Saponaria vaccaria; cyclic peptide; peptide cyclase; orbitide

Effect of particle morphology and size distribution on cold-sprayed pure titanium coatings - Wong, W.; Vo, P.; Irissou, É.; Ryabinin, A. N.; Legoux, J.-G.; Yue, S. (Journal of Thermal Spray Technology, 2013)
The effects of commercially pure titanium particle morphology (spherical, sponge, and irregular) and size distributions (mean particle sizes of 20-49 lm) on the cold spray process and resulting coating properties were investigated. Numerous powder and coating characterizations were performed including: powder oxygen and nitrogen contents, powder ﬂowability, powder compressibility, coating microhardness, coating porosity, LOM/SEM analyses, and XRD. Compared to spherical powders, the sponge and irregular CP-Ti powders had higher oxygen content, poorer powder ﬂowability, higher compression ratio, lower powder packing factor, and higher average particle impact velocities. XRD results showed no new phases present when comparing the various feedstock powders to corresponding coatings. A higher particle temperature was also obtained with larger particle size for all feedstock powder morphologies processed with the same set of spray parameters. A spherical powder with 29 lm mean particle size was found to have the lowest porosity coating and best cold sprayability. The relationships of several as-cold sprayed coating characteristics to the ratio of particle impact and critical velocities were also discussed.
Keywords: cold sprayability; mechanical properties; particle morphology; particle size distribution; particle velocity; titanium

Epoxy/clay nanocomposites : preparation and performance improvement - Ngo, Tri-Dung; Cole, Kenneth Chesley; Ton That, Minh Tan; Van Hoa, Suong (Plastics Research Online, 2013)

Numerical study of laminar flow and mass transfer for in-line spacer-filled passages - Beale, Steven B.; Pharoah, Jon G.; Kumar, Ashwani (Journal of Heat Transfer, 2013)
Performance calculations for laminar fluid flow and mass transfer are presented for a passage containing cylindrical spacers configured in an inline-square arrangement, typical of those employed in the process industries. Numerical calculations are performed for fully-developed flow, based on stream-wise periodic conditions for a unit cell and compared with those obtained for developing regime in a row of ten such units. The method is validated for an empty passage, i.e., a plane duct. Results are presented for the normalized mass transfer coefficient and driving force, as a function of mean flow Reynolds number, and also the wall mass flux, or blowing parameter. Both constant and variable wall velocities were considered, the latter being typical of those found in many practical membrane modules.
Keywords: Computational Fluid dynamics; Periodic boundary conditions; Mass transfer; Membrane

The innovative and sustainable approaches to enhance fire resistance of cellulosic fibers for green polymer composites - Ngo, T-D.; Ton-That, M-T.; Hu, W. (SAMPE Journal, 2013)

Numerical modeling of preferential and in-line heating of semi-transparent thin polymers in stretch blow molding and thermoforming processes - Malo, Alain; Benrabah, Zohir; Thibault, Francis; Bardetti, Anna (SAE Technical Papers; no. 2013-01-1393, 2013)
The heating stage is of primary importance in stretch blow molding and thermoforming processes. Computational methods using the finite element technique for modeling the radiation heating stage of thick gauge plastic preforms and thin gauge, roll-fed plastic sheets are presented and discussed. The theoretical approach as well as the experimental validation are also presented.

Inlet and wall effects on fluid flow in doubly-periodic arrays of spacer-filled passages - Mojab, S. M.; Beale, S. B.; Pollard, A.; Hanff, E. S.; Pharoah, J. G. (Proceedings of the ASME 2013 Summer Heat Transfer Conference collocated with the ASME 2013 7th International Conference on Energy Sustainability and the ASME 2013 11th International Conference on Fuel Cell Science, Engineering and Technology, 2013)
A numerical investigation has been carried out to study the effect of the sidewalls and the number of cells in arrays of spacer-filled channels on the local flow distribution, for Reynolds number, Re = 100, for a spacer-configuration typically employed in process industries. It was found that the channel sidewalls have a significant effect on the velocity profile near the walls. Numerically calculated values of velocity are compared with those measured experimentally, with good agreement being obtained; a maximum deviation of 4.5% was observed. Particle traces emitted from a cell at the channel entrance revealed that, unexpectedly, the flow moves parallel to the spacer filaments within each channel layer and changes 90 degrees direction mostly at the cell adjacent to the channel side walls. The effects of the number of cells and the type of boundary condition imposed on the channel transverse sidewalls on the pressure drop and friction factor are considered.

Self-consistent determination of line-width and probe shape using atomic force microscopy - Eves, B. J.; Green, R. G. (Measurement Science and Technology, 2013)
A self-consistent method for determining line-width and probe shape using an atomic force microscope (AFM) has been developed. Through acquisition of three images in which one tip images the other, and each tip images the sample a least-squares determination of the shapes of both tips, and the parameters that deﬁne the line-width standard can be determined. Application of the self-consistent method produces measurements that can be made traceable to the deﬁnition of the metre through appropriate calibration of the AFM. A comparison between the line-width determined by the method and a calibrated line-width standard shows good agreement. Sources of uncertainty speciﬁc to the self-consistent method are discussed.
Keywords: line-width; probe shape; atomic force microscopy; critical dimension

Structure of Pisum sativum Rubisco with bound ribulose 1,5-bisphosphate - Loewen, Peter C.; Didychuk, Allison L.; Switala, Jacek; Perez-Luque, Rosa; Fita, Ignacio; Loewen, Michele C. (Acta Crystallographica Section F Structural Biology and Crystallization Communications, 2013)
The first structure of a ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) from a pulse crop is reported. Rubisco was purified from Pisum sativum (garden pea) and diffraction-quality crystals were obtained by hanging-drop vapour diffusion in the presence of the substrate ribulose 1,5-bisphosphate. X-ray diffraction data were recorded to 2.20 Å resolution from a single crystal at the Canadian Light Source. The overall quaternary structure of non-activated P. sativum Rubisco highlights the conservation of the form I Rubisco hexadecameric complex. The electron density places the substrate in the active site at the interface of the large-subunit dimers. Lys201 in the active site is not carbamylated as expected for this non-activated structure. Some heterogeneity in the small-subunit sequence is noted, as well as possible variations in the conformation and contacts of ribulose 1,5-bisphosphate in the large-subunit active sites. Overall, the active-site conformation most closely correlates with the `closed' conformation observed in other substrate/inhibitor-bound Rubisco structures.
Keywords: molecular replacement; Pisum sativum; ribulose 1,5-bisphosphate; Rubisco

A generalized sky-LOSA method to quantify soot/black carbon emission rates in atmospheric plumes of gas flares - Johnson, M. R.; Devillers, R. W.; Thomson, K. A. (Aerosol Science and Technology, 2013)
A new generalized theory governing sky-LOSA measurements (line-of-sight attenuation measurements of sky-light) of soot mass flux in atmospheric plumes has been developed which enables accurate measurements in the presence of in-scattered light from the sky and sun. The new approach is quantitatively tested using field measurement data collected for a gas flare at a turbocompressor station in Mexico. Although the soot plume of the tested flare was on the threshold of visible to the naked eye, the sensitivity of the current hardware was more than sufficient to resolve the soot mass emission rate of 0.067 g/s, with a quantified 95% confidence interval of 0.050 to 0.090 g/s. Results of a Monte Carlo simulation showed that soot optical property uncertainty was the major contributor to the overall measurement uncertainty. By contrast, correction of in-scattering via the generalized theory was a comparatively minor contributor, and was specifically insensitive to assumptions about the sky polarization state and intensity distribution. Given the prevalence of flaring and its implication as a potentially critical source of black carbon emissions, sky-LOSA is an essential new technology to directly quantify the impact of these globally distributed sources, for which comparable technologies do not exist.

MicroRNAs and their putative targets in Brassica napus seed maturation - Huang, Daiquing; Koh, Chushin; Feurtado, J. Allan; Tsang, Edward W. T.; Cutler, Adrian J. (BMC Genomics, 2013)
Background : MicroRNAs (miRNAs) are 20–21 nucleotide RNA molecules that suppress the transcription of target genes and may also inhibit translation. Despite the thousands of miRNAs identified and validated in numerous plant species, only small numbers have been identified from the oilseed crop plant Brassica napus (canola) – especially in seeds. Results : Using next-generation sequencing technologies, we performed a comprehensive analysis of miRNAs during seed maturation at 9 time points from 10 days after flowering (DAF) to 50 DAF using whole seeds and included separate analyses of radicle, hypocotyl, cotyledon, embryo, endosperm and seed coat tissues at 4 selected time points. We identified more than 500 conserved miRNA or variant unique sequences with >300 sequence reads and also found 10 novel miRNAs. Only 27 of the conserved miRNA sequences had been previously identified in B. napus (miRBase Release 18). More than 180 MIRNA loci were identified/annotated using the B. rapa genome as a surrogate for the B.napus A genome. Numerous miRNAs were expressed in a stage- or tissue-specific manner suggesting that they have specific functions related to the fine tuning of transcript abundance during seed development. miRNA targets in B. napus were predicted and their expression patterns profiled using microarray analyses. Global correlation analysis of the expression patterns of miRNAs and their targets revealed complex miRNA-target gene regulatory networks during seed development. The miR156 family was the most abundant and the majority of the family members were primarily expressed in the embryo. Conclusions : Large numbers of miRNAs with diverse expression patterns, multiple-targeting and co-targeting of many miRNAs, and complex relationships between expression of miRNAs and targets were identified in this study. Several key miRNA-target expression patterns were identified and new roles of miRNAs in regulating seed development are suggested. miR156, miR159, miR172, miR167, miR158 and miR166 are the major contributors to the network controlling seed development and maturation through their pivotal roles in plant development. miR156 may regulate the developmental transition to germination.
Keywords: Seed development; embryo; next generation sequencing

A comparison of rat SPECT images obtained using ⁹⁹mTc derived from ⁹⁹Mo produced by an electron accelerator with that from a reactor - Galea, R.; Wells, R. G.; Ross, C. K.; Lockwood, J.; Moore, K.; Harvey, J. T.; Isensee, G. H. (Physics in Medicine and Biology, 2013)
Recent shortages of molybdenum-99 (⁹⁹Mo) have led to an examination of alternate production methods that could contribute to a more robust supply. An electron accelerator and the photoneutron reaction were used to produce ⁹⁹Mo from which technetium-99m (⁹⁹mTc) is extracted. SPECT images of rat anatomy obtained using the accelerator-produced ⁹⁹mTc with those obtained using ⁹⁹mTc from a commercial generator were compared. Disks of 100Mo were irradiated with x-rays produced by a 35 MeV electron beam to generate about 1110 MBq (30 mCi) of ⁹⁹Mo per disk. After target dissolution, a NorthStar ARSII unit was used to separate the ⁹⁹mTc, which was subsequently used to tag pharmaceuticals suitable for cardiac and bone imaging. SPECT images were acquired for three rats and compared to images for the same three rats obtained using ⁹⁹mTc from a standard reactor ⁹⁹Mo generator. The efficiency of ⁹⁹Mo–⁹⁹mTc separation was typically greater than 90%. This study demonstrated the delivery of ⁹⁹mTc from the end of beam to the end user of approximately 30 h. Images obtained using the heart and bone scanning agents using reactor and linac-produced ⁹⁹mTc were comparable. High-power electron accelerators are an attractive option for producing ⁹⁹Mo on a national scale.

Qualifying the calibration uncertainty attributable to thermocouple inhomogeneity - Hill, Kenneth D.; Gee, Douglas J. (Book of Abstracts - ITS9 Los Angeles 2012, 2013)
Inhomogeneity in the Seebeck coefficient as a function of position along a thermocouple wire frequently dominates the uncertainty budgets of thermocouple calibration and use. The calibration process itself, simply through exposure to elevated temperatures for relatively modest times, generates both reversible and irreversible changes to the thermocouple that are a complex function of time, temperature, alloy composition, sheath structure, etc. We present data acquired using a salt bath at 250C to provide the step-function-like gradient that is our spatial probe if thermoelectric homogeneity. We show how the finite width of the step-function limits our ability to assess the "true" inhomogeneity of the thermocouple, and explore how the inhomogeneity impacts the calibration uncertainty attainable with the various thermal sources used for the calibration of thermocouples (based on their characteristic temperature gradients).
Keywords: inhomogeneity, Seebeck, thermocouple

Effects of water vapour addition to the air stream on soot volume fraction and flame temperature in a laminar coflow ethylene flame - Liu, Fengshan; Consalvi, Jean-Louis; Fuentes, Andrés; Smallwood, Gregory J. (Proceedings of the 7th International Symposium on Radiative Transfer, RAD-13, 2013)
The effects of adding water vapour to the air stream on flame temperature and soot volume fraction were investigated numerically in a laminar coflow ethylene diffusion flame at atmospheric pressure using a detailed C2 reaction mechanism including PAH. Thermal radiation was calculated using the discrete-ordinates method and a statistical narrowband correlated-k based wide band model for the absorption coefficients of CO2 and H2O. Soot formation was modeled using a PAH based inception model and the HACA mechanism for surface growth and oxidation. The added water vapour affects soot formation and flame properties through not only dilution and thermal effects, but also through chemical and radiation effects. Addition of water vapour significantly reduces radiation heat loss.

Monitoring of potential cytotoxic and inhibitory effects of titanium dioxide using on-line and non-invasive cell-based impedance spectroscopy - Male, Keith B.; Hamzeh, Mahsa; Montes, Johnny; Leung, Alfred C. W.; Luong, John H. T. (Analytica Chimica Acta, 2013)
Titanium dioxide (TiO₂) nanoparticles (NPs) with different sizes and structures were probed for plausible cytotoxicity using electric cell-substrate impedance sensing (ECIS), a non-invasive and on-line procedure for continuous monitoring of cytotoxicity. For insect cells (Spodoptera frugiperda Sƒ9), the ECIS₅₀ values, i.e., the concentration required to achieve 50% inhibition of the response, differed depending on the size and shape of the TiO₂ nanostructure. The lowest ECIS₅₀ value (158 ppm) was observed for the needle shaped rutile TiO2 (10 nm × 40 nm, 15.5 nm nominal particle size), followed by 211 ppm for P-25 (34.1 nm, 80% anatase and 20% rutile), 302 ppm for MTI5 (5.9 nm, 99% anatase) and 417 ppm for Hombitan LW-S bulk TiO₂ (169.5 nm, 99% anatase). Exposure of TiO2 NPs to UV light at 254 nm or 365 nm exhibited no signiﬁcant effect on the ECIS₅₀ value due to the aggregation of TiO₂ NPs with diminishing photocatalytic activities. Chinese hamster lung ﬁbroblast V79 cells, exhibited no signiﬁcant cytotoxicity/inhibition up to 400 ppm with P25, MTI₅ and bulk TiO₂. However, a noticeable inhibitory effect was observed (ECIS₅₀ value of 251 ppm) with rutile TiO₂ as cell spreading on the electrode surface was prevented.
Keywords: Titanium dioxide; cytotoxicity; inhibition; nanoparticles; nano materials; impedance biosensing

Novel polylactide/triticale straw biocomposites : processing, formulation, and properties - Mihai, Mihaela; Ton That, Minh Tan (Polymer Engineering & Science, 2013)
This article aims to the development of polylactide (PLA)/ triticale straw biocomposites with focus on the relationship between triticale straw content, additive presence, processing, and final properties. Prior to melt compounding, the triticale straw used in this study was chopped using the paper process to produce triticale particles that were further pelletized to assure a consistent feed rate into the extrusion line. PLA/triticale straw biocomposites were obtained for different triticale contents from 10 up to 40%vol, without and with maleic anhydride grafted polylactide (PLA-g-MA) as a coupling agent. As a supplementary additive, a PLA-specific branching agentwas used in some selected formulations to minimize the reduction in PLA’s molecular weight. The biocomposites were characterized in terms of rheology, thermal properties, morphology, mechanical properties (tensile, flexural, and impact), and recyclability. The PLAg- MA increased the tensile strength of biocomposites by 10%, whereas boosted the tensile modulus about 2.5 times at 40%vol triticale content. For the same formulation, the flexural strength was raised by 15% and flexural modulus was doubled. However, a combination of PLAg- MA and branching agent proved to be the best approach to enhance PLA/triticale straw mechanical properties. When 20%vol of triticale was used as reinforcement, the presence of branching agent increased the flexural strength about 25%. The results demonstrate that the triticale straw processed in this way could offer a similar reinforcement capability as the cellulosic fibers based on the agricultural and forestry resources and can be easily recycled without losing its mechanical properties. It has a good potential in the biocomposites field with promising applications in construction, common goods, and transportation industries.

Performance analysis and modeling of thermally sprayed resistive heaters - Lamarre, Jean-Michel; Marcoux, Pierre; Perrault, Michel; Abbott, Richard C.; Legoux, Jean-Gabriel (Journal of Thermal Spray Technology, 2013)
Many processes and systems require hot surfaces. These are usually heated using electrical elements located in their vicinity. However, this solution is subject to intrinsic limitations associated with heating element geometry and physical location. Thermally spraying electrical elements directly on surfaces can overcome these limitations by tailoring the geometry of the heating element to the application. Moreover, the element heat transfer is maximized by minimizing the distance between the heater and the surface to be heated. This article is aimed at modeling and characterizing resistive heaters sprayed on metallic substrates. Heaters were fabricated by using a plasma-sprayed alumina dielectric insulator and a wire flame-sprayed iron-based alloy resistive element. Samples were energized and kept at a constant temperature of 425 °C for up to 4 months. SEM cross-sectional observations revealed the formation of cracks at very specific locations in the alumina layer after thermal use. Finite-element modeling shows that these cracks originate from high local thermal stresses and can be predicted according to the considered geometry. The simulation model was refined using experimental parameters obtained by several techniques such as emissivity and time-dependent temperature profile (infra-red camera), resistivity (four-probe technique), thermal diffusivity (laser flash method), and mechanical properties (micro and nanoindentation). The influence of the alumina thickness and the substrate material on crack formation was evaluated.
Keywords: alumina; electrically conductive coatings; finite-element modeling; thermal properties; thermal stress

Strength and wear properties of stainless steel coatings produced by cold spray with various powder sizes - Vo, P.; Irissou, É. (Thermal Spray 2013 : Proceedings of the International Thermal Spray Conference (ASM International), 2013)
Cold spray processing of stainless steel coatings, which represent a cost-effective method for wear and corrosion resistance, has been demonstrated as technically feasible. However, these coatings have a very low tensile strength in the as-sprayed condition, and also may display a marginally higher wear rate. In this study, the cold spray of 316L stainless steel coatings was investigated to characterize the effect of powder size distribution and post-spray heat treatment on strength and wear properties. Coatings on aluminum and steel alloy substrates were produced with a feedstock powder that was obtained in three particle size distributions. The deposition process for all coatings employed nitrogen as the propellant gas and a constant set of spray conditions. A set of screening heat treatments using coupons from coatings produced with one powder size distribution was employed to obtain optimized annealing temperatures. Post-spray annealing at the optimized values was subsequently performed on coatings produced with all three powder size distributions. A comprehensive characterization of the microstructure and mechanical properties, including tensile strength and wear resistance, was performed for coatings produced in the as-sprayed and heat-treated conditions.

Tribological characterization of plasma sprayed CoNiCrAlY-BN abradable coatings - Irissou, É.; Dadouche, A.; Lima, R. S. (Thermal Spray 2013: Proceedings of the International Thermal Spray Conference (ASM International), 2013)
The processing conditions, microstructural and tribological characterizations of plasma sprayed CoNiCrAlY-BN high temperature abradable coatings are reported in this manuscript. Plasma spray torch parameters were varied to produce a set of abradable coatings exhibiting a broad range of porosity levels (34-62%) and superficial Rockwell hardness values (0-78 HR15Y). Abradability tests have been performed using an abradable-seal test rig capable of simulating operational wear at different rotor speeds and seal incursion rates. These tests allowed determining the rubbing forces and quantifying the blade and seal wear characteristics for slow and fast seal incursion rates. Erosion wear performance and ASTM C633 coating adhesion strength test results are also reported. For optimal abradability performance, it is shown that coating hardness needs to be lower than 70 and 50 HR15Y for slow and fast blade incursion rate conditions, respectively. It is shown that the erosion wear performance, as well as, the coating cohesive strength is a function of the coating hardness. The current results allow defining the coating specifications in terms of hardness and porosity for targeted applications.

Cold spray deposition of mechanically alloyed Cu–Ni–Fe material for application as inert anodes for aluminum production - Goupil, G.; Helle, S.; Irissou, É.; Poirier, D.; Legoux, J. G.; Guay, D.; Roué, L. (Light Metals 2013, 2013)
Cold spray deposition was evaluated for the production of inert anodes for Al electrolysis from mechanically alloyed Cu−Ni−Fe powders. Cu65Ni20Fe15 (in wt. %) alloy was first prepared from elemental Cu, Ni, Fe powders using an attritor. After 40 h of milling, a nanocrystalline and monophasic Cu(Ni,Fe) solid solution was formed. It was shown that the particle size of the milled powder can be controlled with the addition of stearic acid to the initial powder mixture. In a second step, the cold spray parameters (pressure and temperature of the carrier N2 gas) were optimized in order to maximize the impact velocity of the Cu65Ni20Fe15 particles on the substrate. Then, thick (1100 μm), dense (porosity of 1− 2 %) and adherent (adhesion strength of 15 MPa) coatings of Cu65Ni20Fe15 on C63000 substrate (copper aluminium bronze alloy) were produced. No structural change of the Cu65Ni20Fe15 alloy was observed during cold spray processing.
Keywords: aluminum electrolysis; inert anode; Cu-Ni-Fe alloys; cold spray deposition; low-temperature electrolyte

Polyamide 12 (PA12) / clay nanocomposites fabricated by conventional extrusion and water-assisted extrusion processes - Stoeffler, Karen; Utracki, Leszek A.; Simard, Yves; Labonté, Sylvain (Journal of Polymer Science, 2013)
This work aims at comparing the efficiency of three melt compounding methods for preparing polyamide 12 (PA12)/untreated clay composites. Conventional extrusion was compared with two water-assisted extrusion methods previously described in the literature and respectively involving injection of water in the polymer/clay stream or injection of aqueous clay slurry in the polymer stream. The dispersion of the clay in the composites was analyzed at the microscale and at the nanoscale using microscopy (optical and electronic) and wide angle X-ray diffraction (WAXD). The tensile properties of the composites were evaluated. The results showed that injection of aqueous clay slurry in the polymer stream was the most efficient method for preparing PA12/untreated clay composites, although clay particles remained mainly dispersed at the microscale. This method allowed for a drastic size reduction of the microparticles, accompanied by enhancements of ca. +10 % in tensile modulus and tensile strength (compared with equivalent composites obtained by conventional extrusion). The influence of the pH of the aqueous clay slurry was also investigated: neutralization of the clay slurry generated finer dispersions, probably resulting from a better pre-exfoliation of the clay in the water medium. PA12/organophilic clay composites were also prepared as control samples. When an adequate surface treatment was selected, nanoscale dispersion of the clay platelets was easily achieved. In this case, composites prepared by conventional extrusion showed overall similar properties as their equivalents prepared using injection of water in the polymer/clay stream.
Keywords: composites; clay; extrusion

Controlling the forming of thermoplastics through forming power - Girard, Patrick; Benrabah, Zohir; Mir, Hicham (SAE Technical Papers; no. 2013-01-0602, 2013)
Controlling the forming of large thermoplastic parts from a simulation requires very precise predictions of the pressure and volume profile evolution. Present pressure profile based simulations adequately predict the thickness distribution of a part, but the forming pressure and volume profile development lack the precision required for process control. However new simulations based on the amount of power required to form the material can accurately predict these pressure and volume profiles. In addition online monitoring of the forming power on existing machines can be easily implemented by installing a flow rate and pressure meter at the gas entrance, and if necessary, exits of the part. An important additional benefit is that a machine thus equipped can function as an online rheometer that can characterize the viscosity of the material at the operating point by tuning the simulation to the online measurements. This method can characterize materials at the actual, very high strain rates, that are not attainable by conventional characterization methods, and also allows online detection of variations in the rheology of the resin. The rheological model of the material is then updated to fit this point, which would normally lie outside of the characterization range. A basic implementation for a cycle to cycle control system for thermoforming of plastic materials is proposed. The system controls the development of the pressure and volume profile in the part while adjusting to operating conditions, including changes in resin rheology. It ensures that the part is consistently formed cycle after cycle using the same strain rate profiles. A forming power based simulation is run in the background with the rheological model tuned to fit the operating point as shown above. A simple linear sensitivity matrix is then derived from the simulation. Since this linear sensitivity matrix is defined in the vicinity of the actual operating point and provides a much faster response time than the simulation, it can be used as the core of an online forming process control system. The system is applicable to large parts with slow deformation such as gas tanks, and small parts with very high rates of deformation such as angioplasty balloons.

Thermo-viscoelastic model for shrinkage and warpage prediction during cooling and solidification of automotive blow molded parts - Benrabah, Zohir; Mir, Hicham; Zhang, Yi (SAE International Journal of Materials and Manufacturing, 2013)
Blow moulding is one of the most important polymer processing methods for producing complex thermoplastic automotive parts. Contrary to injection molding, little attention has focused on process control and simulation of blow molding processes. Yet, there are still several problems that affect the overall success of forming these parts. Among them are thermally induced stresses, relevant shrinkage and part warpage deformations caused by inappropriate mold design and/or processing conditions. Tolerance issues are critical in automotive applications and therefore part deformation due to solidification needs to be controlled and optimized accordingly. The accurate prediction tool of part deformation due to solidification, under different cooling conditions in automotive formed parts, is important and highly suited for part designers to help achieve an efficient production.

Thermodynamic and energetic effects on the diameter and defect density in single-walled carbon nanotube synthesis - Vinten, Phillip; Marshall, Paul; Lefebvre, Jacques; Finnie, Paul (The Journal of Physical Chemistry C, 2013)
Single-walled carbon nanotube (SWCNT) ensembles are characterized by their defect density and diameter distribution. Here, SWCNTs are grown using chemical vapor deposition with acetylene as the carbon source and cobalt as the catalyst and analyzed ex situ, without any modification or processing, using Raman spectroscopy. The defect density shows an activated temperature dependence (activation energy ∼0.8 eV or ∼80 kJ/mol) with fewer defects at high growth temperatures for a wide range of experimental parameters. This is consistent with a single activated mechanism, such as the catalytic healing of defects, possibly a single simple defect. Consistent with previous reports, we see that low growth temperatures produce smaller diameter SWCNTs than high growth temperatures. Elementary thermodynamic considerations of the strain energy in the lattice constrain the SWCNT diameter distribution and its temperature dependence and appear consistent with our observations. A “phase diagram” for SWCNT growth is constructed and suggests methods of controlling the diameter distribution. There is a trade-off here between small diameter SWCNTs and SWCNTs with low defect densities.

Magnetic imaging with a Zernike-type phase plate in a transmission electron microscope - Pollard, Shawn; Malac, Marek; Beleggia, Marco; Kawasaki, Masahiro; Zhu, Yimei (Applied Physics Letters, 2013)

A real-time rocking motion monitoring system - Wu, Lixue (Proceedings of the 19th International Congress on Sound and Vibration 2012, 2013)

Hybrid fire testing for assessing performance of structures in fire—application - Mostafaei, Hossein (Fire Safety Journal, 2013)
This paper presents the results for application and implementation of the hybrid fire testing (HFT) approach, developed previously for performance assessment of the structure in fire. The HFT carried out by means of both computer simulation and experimentation using the National Research Council Canada's (NRC) testing facilities in Ottawa. The test specimen was a full-scale 6-storey building structure with a fire compartment scenario on the main floor of the building. Using the HFT, the column in the designated fire compartment was exposed to the fire in a column furnace and the rest of the building was simulated using a numerical modeling, simultaneously. The methodology of the HFT and its numerical verifications were developed and described in a previous paper. This paper includes application of the HFT and some of results for fire structural performance of the whole 6-storey building. It also includes results of a separate, benchmark, column specimen with identical specifications, tested in fire using the traditional prescriptive fire resistance test method. The HFT was carried out successfully. The results indicated that the hybrid fire testing method would provide more realistic fire endurance evaluation than the prescriptive method due to including the effects from the rest of the building on the column specimen during the test.
Keywords: Hybrid test; Fire resistance; Performance-based design; Hybrid test; Full-scale test; Test and analysis/simulation; Hybrid fire testing; HFT; Standard fire resistance test

A uniform methodology to establish test parameters for watertightness testing part II: Pareto front analysis on co-occurring rain and wind - Van Den Bossche, Nathan; Lacasse, Michael A.; Janssens, Arnold (Building and Environment, 2013)
A critical review on boundary conditions for watertightness testing was presented in a related paper forming Part I of “A uniform methodology to establish test parameters for watertightness testing”. Existing methodologies to establish test conditions only partially consider co-occurrence of rain and wind, which yields large uncertainties when determining return periods for extreme wind-driven rain events. This paper presents a new approach based on a Pareto fronts method for which wind driven rain intensities and wind pressures are derived. Straight lines can be fitted to consecutive fronts, and a generalized Pareto distribution describes the corresponding probabilities of occurrence of wind-driven rain events. Assumptions in the use of the methods are given and constraints to its use provided by means of case-studies. Advantages over existing methods for estimating watertightness test parameters are highlighted. Test conditions can be calculated for various configurations and different averaging periods depending on the failure behavior of specific building envelop components. Subsequently it is shown that the conversion of case-based test conditions to generic test protocols and performance levels requires careful consideration. Finally, the paper provides practical guidelines on defining realistic watertightness performance levels for building envelop components.
Keywords: Watertightnes; Testing; Wind driven rain; Co-occurrence; Pareto front

A uniform methodology to establish test parameters for watertightness testing Part I: A critical review - Van den bossche, Nathan; Lacasse, Michael A.; Janssens, Arnold (Building and Environment, 2013)
Many of the standards and codes related to watertightness of building components in use today have a long history and in most cases their roots were conceived decades ago. Irrespective of the broad spectrum of research on wind loads, rainfall and wind driven rain (WDR) intensity, little information is available concerning the scientific basis for watertightness test methods or performance criteria. This paper provides an overview of existing methodologies to establish test conditions and a critical review of calculation methods for wind and WDR loads on buildings, from the viewpoint of establishing test parameters for watertightness testing. The operative standard in the field of structural engineering is extended with a gust model to calculate wind loads for varying configurations, return periods and gust lengths, and model implications are discussed. A state-of-the-art on intensity–duration–frequency curves of horizontal rainfall intensity is given, and a new approach to accommodate conflicting models is presented. Furthermore, based on recent advances in WDR research, an adapted semi-empirical model is suggested to calculate extreme WDR intensities on building façades. For two locations boundary conditions for watertightness testing were calculated based on datasets extending over 10 years of 10-min averaged values. Finally, constraints and challenges in extreme value analysis in respect to cut-off values, fitting algorithms, goodness-of-fit (GOF) criteria and co-occurrence of rain and wind are discussed.
Keywords: Watertightness; Testing; Wind driven rain; Co-occurrence; Pareto front; Review

Expressing full-length functional PfEMP1 proteins in the HEK293 expression system - Srivastava, Anand; Durocher, Yves; Gamain, Benoît (Malaria, 2013)
Due to the A/T-richness of the genome of Plasmodium falciparum, expressing P. falciparum proteins in heterologous expression systems is challenging. In addition, many P. falciparum proteins have high cysteine content and high molecular weight, which further complicates expression of these proteins in heterologous systems. The high molecular weight Plasmodium falciparum Erythrocyte Membrane Protein 1 (PfEMP1) adhesins expressed on the surface of the infected erythrocytes are among the most difficult proteins to express. Cost reduction in synthetic gene synthesis, as well as improved eukaryotic expression systems, now makes it possible to express such proteins. In this chapter, we describe the construction, production, purification, and functional assessment of the full-length extracellular region of the var2CSA PfEMP1 protein involved in pregnancy-associated malaria (PAM), using a human embryonic kidney (HEK) expression system.

Reflections on service to CPA. - Veitch, Jennifer A. (Canadian Psychology/Psychologie canadienne, 2013)
The rewards for service to a professional association are many: reputation-building, power, and influence; skill development; networking opportunities; feelings of mastery and belonging. These serve to maintain the behaviours despite occasional dull or routine tasks required in the service role. Voluntary service of this kind is essential to the maintenance of psychological research, practice, and education; arguably it ensures that psychologists can continue to be psychologists. Disciplinary service ensures a strong common core of knowledge, language, and culture to support interdisciplinary and interprofessional endeavours.
Keywords: psychology; Canadian Psychological Association; voluntarism; service; scientific discipline; interdisciplinarity

Sustained production of a soluble IGF-I receptor by gutless adenovirus-transduced host cells protects from tumor growth in the liver - Wang, N.; Lu, Y.; Pinard, M.; Pilotte, A.; Gilbert, R.; Massie, B.; Brodt, P. (Cancer Gene Therapy, 2013)
The IGF-I receptor (IGF-IR) has an important role in malignant disease and is the target of several drugs presently in clinical trials. Gene therapy has been explored as cancer treatment, mainly for delivery of genes that induce cell death or enhance the immunological response to cancer. Previously, we have shown that the implantation of autologous bone-marrow stromal cells producing a soluble form of IGF-IR (sIGFIR) inhibited experimental liver metastasis of several tumor types in mice. Here, we evaluated the utility of adenovirus-based gene delivery for generating therapeutically effective plasma levels of this decoy. We constructed a third generation gutless adenovirus expressing sIGFIR and found that HEK-293 cells transduced by this, but not control adenoviruses, secreted soluble receptor protein that blocked IGF-I-induced tumor cell migration, proliferation and survival in vitro. Following virus injection in vivo, viral DNA was detectable by PCR in several host organs, particularly the liver, and this resulted in the production of measurable sIGFIR plasma levels for up to 21 days post injection. In mice producing virus-encoded sIGFIR, experimental liver metastasis was inhibited, indicating that sIGFIR levels were therapeutically effective. The results show that adenovirus-based delivery of inhibitory soluble proteins can provide an effective anticancer strategy.
Keywords: cancer; gutless adenoviral vector; liver metastases; soluble IGF-IR

Papain - Storer, Andrew C.; Ménard, Robert (Handbook of Proteolytic Enzymes, 2013)

Cathepsin X - Nägler, Dorit K.; Ménard, Robert; Sulea, Traian (Handbook of Proteolytic Enzymes (3rd edition), 2013)
The third edition of the Handbook of Proteolytic Enzymes aims to be a comprehensive reference work for the enzymes that cleave proteins and peptides, and contains over 800 chapters. Each chapter is organized into sections describing the name and history, activity and specificity, structural chemistry, preparation, biological aspects, and distinguishing features for a specific peptidase. The subject of Chapter 415 is Cathepsin X.
Keywords: active-site-prob; adhesion; Alzheimer; cancer; carboxypeptidase; immunity; inflammation; inhibitor; integrin; migration; mini-loop; monopeptidyl; specificity; structure; substrate

Hybrid fire testing for assessing performance of structures in fire—methodology - Mostafaei, Hossein (Fire Safety Journal, 2013)
A new performance-based assessment approach for structures in fire, referred to as hybrid fire testing (HFT) method, is presented in this article. The HFT was developed based on a sub-structuring method, by dividing the whole structure into two substructures, one being tested in a furnace and one being simulated by a computer. This represents a form of “hardware-in-the-loop” simulation. Using HFT, the performance of the whole building can be evaluated at a very reasonable cost, significantly less than the cost of the direct whole building test. More reliable results than the prescriptive method can also be achieved with comparable and even more comprehensive results than that of a direct full-scale test. A 6-storey reinforced concrete building was designed, as a prototype for application of the hybrid fire testing approach. Two fire scenario examples were considered; a 6-storey building with a fire compartment on the first floor, in the center of the building and a 6-storey building with a fire compartment on the third floor. The two substructures for these two HFT scenarios were; one the column in the fire compartment and two the rest of the building. This paper includes the description of the hybrid testing methodology, details of the 6-storey building prototype and the methodology verification. Using the HFT approach, various scenarios could be explored to couple modeling and testing globally. This may also provide the possibility of running one test in a testing facility, e.g. NRC's, and running the analysis remotely at a different location. This would make furnace facilities more accessible to the research communities around the globe.
Erratum published in volume 61, page 355, October 2013. DOI: 10.1016/j.firesaf.2013.10.001
Keywords: Fire resistance; Performance-based design; Hybrid test; Full-scale test; Test and analysis/simulation; Hybrid fire testing

Terrestrial ecotoxicity of canola and tallow-biodiesel blended with ulta-low sulphur diesel (PL) - Rocheleau, S.; Sarrazin, M.; Dodard, S.; Beaulieu, C.; Hawari, J.; Hollebone, B.; Sunahara, G.; Harkness, J.; van Aggelen, G.; Kennedy, C. J.; Jarvis, R. Allen; Burridge, L. E. (Proceedings of the 39th Annual Aquatic Toxicity Workshop : September 30-October 3, 2012, Sun Peaks, British Columbia, 2013)
Biodiesel is becoming an interesting alternative fuel source considering the continuously diminishing petroleum resources. Biodiesel can be produced from either plant or animal feedstocks, and its storage, transport, and use may pose potential environmental problems to soil and groundwater. Aquatic toxicities of diesel and biodiesel have been extensively studied, but little is still known about their toxicities and environmental fate in soil. The present study evaluates the potential environmental impacts of biodiesel and petroleum ultra-low-sulphur based diesel (ULSD) blended with biodiesel in soil using direct contact toxicity assays. Canola-source biodiesel (B100) and a tallow-source biodiesel (B100) alone and as 20% (volume/volume) blends with ULSD (B20) were compared to neat ULSD. Selected standard terrestrial toxicity tests included ryegrass Lolium perenne seedling emergence and growth, earthworm Eisenia fetida survival, and soil microbial dehydrogenase activity (DHA). Soil loading was quantified using extractable n-alkanes (C10 to C34 hydrocarbons). Results indicate that both B20 biodiesel blends had less deleterious effects to ryegrass growth and earthworm survival than the petroleum ULSD, whereas both B100 biodiesel samples had no deleterious effect on ryegrass growth or earthworm survival at concentrations up to 6310 and 6613 mg n-alkanes·kg⁻¹, respectively. Petroleum ULSD and B20 canola biodiesel inhibited the DHA microbial activity, whereas tallow biodiesel (B20 and B100) and B100 canola biodiesel stimulated the DHA activity. This study provides useful toxicological data for the evaluation of potential adverse impact and risk assessment of biodiesel in the environment.

Nutrient remediation rates in municipal wastewater and their effect on biochemical composition of the microalga Scenedesmus sp. AMDD - Dickinson, Kathryn E.; Whitney, Crystal G.; McGinn, Patrick J. (Algal Research, 2013)
Microalgae are very efﬁcient at removing nutrients from municipal wastewater and may be a viable tertiary wastewater treatment while additionally improving the economics of microalgal cultivation for biofuel production. The relative quantities and productivities of fatty acids, carbohydrates and proteins were determined in the microalga Scenedesmus sp. AMDD grown in treated municipal wastewater in continuous chemostats under different dilution rates or hydraulic retention times. The dilution rate of the chemostat exerted a strong control over the biochemical composition of the cultivated biomass and clear differences in the patterns of accumulation of cellular constituents were detected. Maximum carbohydrate and protein productivities were estimated to be 130 and 120 mg L⁻¹ d⁻¹, respectively, at dilution rates of 0.5 d⁻¹ and 1.05 d⁻¹, respectively. Fatty acid productivity was fairly constant at about 20 mg L⁻¹ d⁻¹ across all tested dilution rates. Total fatty acid only accumulated when growth rates were very low or when a prolonged nutrient starvation regime was imposed by interrupting the supply of wastewater to the chemostat. Monounsaturated fatty acids increased by 250%, whereas polyunsaturated fatty acids decreased by 60% and saturated fatty acids remained fairly constant, from the highest dilution rate of 1.05 d⁻¹ to nutrient starved cells. The rate of wastewater nutrient remediation therefore strongly controls the composition of the biomass, thereby controlling its commercial applicability.
Keywords: Microalgae; Chemostat; Bioenergy; Biofuels; Wastewater

Isolation and characterization of herbaceous lignins for applications in biomaterials - Monteil-Rivera, Fanny; Phuong, Marielle; Ye, Mengwei; Halasz, Annamaria; Hawari, Jalal (Industrial Crops and Products, 2013)
The imminent industrial production of cellulosic ethanol from annual plants will generate massive amounts of herbaceous lignins that will have to be valorized. However, the chemical and physical properties of herbaceous lignins are much less known than those of wood lignins. In the present study, organosolv lignins were extracted from wheat, triticale, corn, ﬂax, and hemp residues using microwave irradiation under similar conditions. The extracted lignins were extensively analyzed by FT-IR, ³¹P NMR, gel permeation chromatography, thermogravimetric analysis, and elemental and carbohydrate analysis to determine their applicability in polymers. All lignins were of high purity with low sugar, sulfur, and ash content. Corn, hemp, and ﬂax lignins were found to contain high concentrations of non-methoxylated phenolic groups, syringyl phenolic groups, and aliphatic OH groups, respectively, making them promising candidates for production of phenolic resins, stabilization of polyoleﬁns, and polyurethane synthesis, respectively. Triticale or wheat lignins were less speciﬁc, with a balanced content of OH groups, which makes them applicable to polyester synthesis.
Keywords: Herbaceous lignin; microwave; functional groups; molecular weight; thermal stability; biomaterials

Soot temperature and volume fraction retrieval from spectrally resolved flame emission measurement in laminar axisymmetric coflow diffusion flames : Effect of self-absorption - Liu, Fengshan; Thomson, Kevin A.; Smallwood, Gregory J. (Combustion and Flame, 2013)
The effects of self-absorption on the inverted soot temperature and volume fraction distributions in coflow laminar diffusion flames were investigated using two correction methods. Self-absorption was found unimportant when the optical thickness of the flame is less than 0.3, but can be very important in flames of large optical thicknesses. Due to the uncertainty in soot absorption function E(m), different assumptions of the variation of E(m) with wavelength were investigated. Decreasing E(m) with wavelength leads to largest errors in the recovered soot temperature and volume fraction when self-absorption correction is not accounted for. The assumption of constant E(m) in general results in smallest errors in the inverted soot volume fraction and the increasing E(m) with wavelength gives rise to smallest errors in the recovered soot temperature. Neglect of self-absorption correction in general leads to underestimate of the inverted soot temperature, while the inverted soot volume fraction can be higher or lower than the true value, depending on how E(m) varies with wavelength. The self-absorption correction method of Snelling et al. [D.R. Snelling, K.A. Thomson, G.J. Smallwood, Ö.L. Gülder, E.J. Weckman, R.A. Fraser, AIAA J. 40(9) (2002) 1789–1795] is effective in recovering accurate soot temperature and volume fraction distributions from noise-free emission data even for flames with optical thickness as large as 5. For inversion of emission data containing noise it is still advantageous to account for self-absorption. Multi-wavelength emission data from a laminar coflow ethylene/air diffusion flame at atmospheric pressure and a methane/air diffusion flame at 40 atm were reanalyzed to demonstrate how self-absorption affects the reconstructed temperature and soot volume fraction distributions. It is preferred to detect flame emissions at longer wavelengths in the visible spectrum to minimize the self-absorption effect. The effect of self-absorption should in general be taken into account in the reconstruction of soot temperature and volume fraction from the line-of-sight spectral flame emission data using the method of Snelling et al.
Keywords: soot measurement; line-of-sight spectral flame emission; self-absorption; Abel inversion

Final report on CCM key comparison CCM.D-K2 : comparison of liquid density standards - Bettin, Horst; Jacques, Claude; Zelenka, Zoltan; Fujii, Ken-ichi; Kuramoto, Naoki; Chang, Kyung-Ho; Lee, Yong Jae; Becerra, Luis Omar; Domostroeva, Natalia (Metrologia, 2013)
The results are presented of the key comparison CCM.D-K2 that covered the density measurements of four liquids: the density of water at 20 °C, of pentadecane at 15 °C, 20 °C, 40 °C and 60°C, of tetrachloroethlyene at 5 °C and 20 °C and of a viscous oil at 20 °C. Seven national metrology institutes measured the densities at atmospheric pressure by hydrostatic weighing of solid density standards in the time interval from 27 April 2004 to 28 June 2004. Since the participants were asked not to include components for a possible drift or inhomogeneity of the liquid in their uncertainty budget, these uncertainty contributions are investigated for the final evaluation of the data. For this purpose, results of stability and homogeneity measurements of the pilot laboratory are used. The participants decided not to include a possible drift of the liquid's density since no significant drift could be detected, and the influence of the drift and its uncertainty are negligible. Similarly, the inhomogeneity of the water and pentadecane samples is not significant and has no influence on the evaluation. Thus, it was neglected. Only the inhomogeneities of tetrachloroethylene and of the viscous oil were significant. Consequently, they were included in the evaluation. With one or two exceptions, the results show good agreement among the participants. Only in the case of water are the results clearly discrepant. The key comparison reference values were calculated by the weighted mean (taking into account a small correlation between two participants) in the case of consistent results. Otherwise the Procedure B of Cox was used. The expanded uncertainties of all reference densities are below 1 × 10−5 in relative terms. This satisfies the needs of all customers who wish to calibrate or check liquid density measuring instruments such as oscillation-type density meters. The comparison fully supports the calibration measurement capabilities table in the BIPM key comparison database. The results can be used to link regional comparisons to this CCM key comparison.

Evaluation of systematic shifts of the 88Sr+ single-ion optical frequency standard at the 10−17 level - Dube, Pierre; Madej, Alan A.; Zhou, Zichao; Bernard, John E. (Physical Review A, 2013)
An ion trap of the end-cap design was built recently at the National Research Council of Canada for improved control of the 88Sr+ single-ion optical frequency standard systematic shifts. The uncertainty on the micromotion-induced shifts is smaller by more than four orders of magnitude when compared to our previous trap system and reaches a fractional frequency uncertainty of 1×10−18. To obtain this low uncertainty level, the micromotion is minimized with trim electrodes and the trap is operated at a special frequency at which there is anticorrelation between the second-order Doppler and Stark shifts. This choice of operating frequency, determined by the differential scalar polarizability of the clock transition, yields a suppression by a factor of ≈28 in the combined micromotion shifts. Like many optical frequency standards, the dominant source of uncertainty in the new trap is the blackbody radiation shift. Its uncertainty has been reduced by an order of magnitude with a recent theoretical evaluation of the differential scalar polarizability of the clock transition. The fractional blackbody shift uncertainty, estimated using a model of the blackbody field at the ion, is 2.2×10−17. The otherwise dominant electric quadrupole shift is reduced to below the 3×10−19 level with a cancellation method based on the average frequency of several pairs of Zeeman components. This method also cancels the tensor Stark shift and simplifies the description of the frequency shifts that are quantization-axis dependent. This paper provides a detailed description of the 88Sr+ optical frequency standard uncertainty evaluation and the methods used to make the standard robust against changes in the trap environment. The total fractional frequency uncertainty of the 88Sr+ ion for our current system is estimated at 2.3×10−17. We also discuss the uncertainty evaluation of a recently reported measurement of the 88Sr+ S-D clock transition made over a 2-month period by comparison with a maser referenced to the SI second. The frequency measured is 444 779 044 095 485.5(9) Hz, with an uncertainty limited by the evaluation of the maser frequency.

Low-frequency quantum-based AC Power Standard at NRC Canada - Djokic, Branislav (2012 Conference on Precision Electromagnetic Measurements (CPEM 2012), 2013)
A low-frequency AC Power Standard based on the Programmable Josephson Voltage Standard (PJVS) has been developed at the National Research Council (NRC) of Canada. At the step voltages, PJVS provides quantum accuracy. Differential digital sampling is used to extend the quantum accuracy to the AC Power Standard output voltage and current, nominally 120 V and 5 A. The paper describes the evaluation of the power standard and its components.
Keywords: AC power standard; programmable Josephson Voltage Standard; inductive voltage dividers; current transformers; calibration

Discovery of gymnodimine fatty acid ester metabolites in shellfish using liquid chromatography/mass spectrometry - de la Iglesia, P.; McCarron, P.; Diogene, J.; Quilliam, M. A. (Rapid Communications in Mass Spectrometry, 2013)
Gymnodimines (GYMs) are fast-acting toxins that belong to the cyclic imine group, a subclass of lipophilic marine toxins. GYMs are considered to be emerging toxins but have not yet been linked to incidents of human poisoning, Limited knowledge on the metabolism of GYMs means that a proper risk assessment has not been possible and caution must be taken when establishing the relevance of GYMs in terms of food safety of marine products.

14N overtone NMR spectra under magic angle spinning : experiments and numerically exact simulations - O'Dell, Luke A.; Brinkmann, Andreas (The Journal of Chemical Physics, 2013)
It was recently shown that high resolution 14N overtone NMR spectra can be obtained directly under magic angle spinning (MAS) conditions [L. A. O’Dell and C. I. Ratcliffe, Chem. Phys. Lett. 514, 168 (2011)]10.1016/j.cplett.2011.08.030. Preliminary experimental results showed narrowed powder pattern widths, a frequency shift that is dependent on the MAS rate, and an apparent absence of spinning sidebands, observations which appeared to be inconsistent with previous theoretical treatments. Herein, we reproduce these effects using numerically exact simulations that take into account the full nuclear spin Hamiltonian. Under sample spinning, the 14N overtone signal is split into five (0, ±1, ±2) overtone sidebands separated by the spinning frequency. For a powder sample spinning at the magic angle, the +2ωr sideband is dominant while the others show significantly lower signal intensities. The resultant MAS powder patterns show characteristic quadrupolar lineshapes from which the 14N quadrupolar parameters and isotropic chemical shift can be determined. Spinning the sample at other angles is shown to alter both the shapes and relative intensities of the five overtone sidebands, with MAS providing the benefit of averaging dipolar couplings and shielding anisotropy. To demonstrate the advantages of this experimental approach, we present the 14N overtone MAS spectrum obtained from L-histidine, in which powder patterns from all three nitrogen sites are clearly resolved.

Atmospheric plasma sprayed Forsterite (Mg2SiO4) coatings : an investigation of the processing-microstructure-performance relationship - Cojocaru, C. V.; Lamarre, J.-M.; Legoux, J.-G.; Marple, B. R. (Journal of Thermal Spray Technology, 2013)
Evaluating and understanding the relationship between processing, microstructure and performance of a dielectric coating is essential for its practical usage and reliable application. In this study, the role of the powder feedstock on the properties of atmospheric plasma sprayed forsterite (Mg₂SiO₄) dielectric coatings was investigated by using different forsterite powder granulometries. The microstructural and porosity characteristics of the coatings associated with the spray conditions employed were assessed via scanning electron microscopy (SEM) and image analysis. The phase composition of the coatings was studied via x-ray diffraction and their crystallinity index determined. The electrical insulating characteristics were investigated using the dielectric breakdown test and impedance spectroscopy measurements. The electrical properties obtained were correlated with the microstructural characteristics and a performance comparison between forsterite and other dielectric coatings is presented.
Keywords: coefficient of thermal expansion; dielectric coatings; dielectric strength; forsterite; plasma-spray

Reptation model for the dynamics and rheology of particle reinforced polymer chains - Mittal, Vikas; Kabanemi, Kalonji K.; Hétu, Jean-François (Modeling and Prediction of Polymer Nanocomposite Properties, 2013)
Keywords: Polymer-particle energetic interaction; reptation model; mean-square displacement (MSD); Rouse relaxation time; polymer dynamics; Rouse relaxation

Cold spray forming of Inconel 718 - Wong, W.; Irissou, É.; Vo, P.; Sone, M.; Bernier, F.; Legoux, J.-G.; Fukanuma, H.; Yue, S. (Journal of Thermal Spray Technology, 2013)
Inconel 718 was cold spray formed to a 6-mm thickness on an 8-cm diameter aluminum alloy tube using Sulzer Amdry 1718 powder and the Plasma Giken PCS-1000 cold spray system. The effects of spray particle velocity and post-spray heat treatment were studied. Post-spray annealing was performed from 950 to 1250ºC for 1-2 h. The resulting microstructures as well as the corresponding mechanical properties were characterized. As-sprayed coatings exhibited very low ductility. The tensile strength and ductility of the heat-treated coatings were improved to varying levels depending on the heat-treatment and spray conditions. For coatings sprayed at higher particle velocity and heat treated at 1250ºC for 1 h, an elongation of 24% was obtained. SEM micrographs showed a higher fraction of interparticle metallurgical bonds due to some sintering effect. Corresponding fracture surfaces also revealed a higher fraction of dimple features, typically associated with ductile fracture, in the annealed coatings. The results demonstrate that cold spray forming of Inconel 718 is feasible, and with appropriate heat treatment, metallurgical bonding can be increased. The ductility of the spray-formed samples was comparable to that of the bulk material.
Keywords: coatings for engine components; cold spray; cold gas dynamic spraying; Inconel; mechanical properties; spray forming

A new interface element with progressive damage and osseointegration for modeling of interfaces in hip resurfacing - Caouette, Christiane; Bureau, Martin N.; Lavigne, Martin; Vendittoli, Pascal-André; Nuño, Natalia (Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, 2013)
Finite element models of orthopedic implants such as hip resurfacing femoral components usually rely on contact elements to model the load-bearing interfaces that connect bone, cement and implant. However, contact elements cannot simulate progressive degradation of bone–cement interfaces or osseointegration. A new interface element is developed to alleviate these shortcomings. This element is capable of simulating the nonlinear progression of bone–cement interface debonding or bone–implant interface osseointegration, based on mechanical stimuli in normal and tangential directions. The new element is applied to a hip resurfacing femoral component with a stem made of a novel biomimetic composite material. Three load cases are applied sequentially to simulate the 6-month period required for osseointegration of the stem. The effect of interdigitation depth of the bone–cement interface is found to be negligible, with only minor variations of micromotions. Numerical results show that the biomimetic stem progressively osseointegrates (α averages 0.7 on the stem surface, with spot-welds) and that bone–stem micromotions decrease below 10 µm. Osseointegration also changes the load path within the femoral bone: a decrease of 300 µε was observed in the femoral head, and the inferomedial part of the femoral neck showed a slight increase of 165 µε. There was also increased stress in the implant stem (from 7 to 11 MPa after osseointegration), indicating that part of the load is supported through the stem. The use of the new osseointegratable interface element has shown the osseointegration potential of the biomimetic stem. Its ability to model partially osseointegrated interfaces based on the mechanical conditions at the interface means that the new element could be used to study load transfer and osseointegration patterns on other models of uncemented hip resurfacing femoral components.
Keywords: Bone-implant interface; bone-cement interface; hip resurfacing prosthesis; biomimetic composite material; finite element analysis

A new osseointegratable and damageable interface element for modeling of bone implant and bone-cement interface - Caouette, Christiane; Bureau, Martin; Vendittoli, Pascal-André; Lavigne, Martin; Nuño, Natalia (EORS 2012 Amsterdam : European Orthopaedic Research Society 20th Annual Meeting Proceedings, 2013)
We propose a new robust modeling method for the finite element modeling of load-transmitting bone-cement and bone-implant interfaces. This new modeling method allows simulation of osseointegration and progressive debonding.

Engineering HVOF-Sprayed Cr3C2-NiCr coatings : the effect of particle morphology and spraying parameters on the microstructure, properties, and high temperature wear performance - Poirier, Dominique; Legoux, Jean-Gabriel; Lima, Rogerio S. (Journal of Thermal Spray Technology, 2013)
Chromium carbide-based thermally sprayed coatings are widely used for high temperature wear applications (typical temperature range from 540 to 900ºC). In these extreme environments at those temperatures, several phenomena will degrade, oxidize, and change the microstructure of the coatings, thereby affecting their wear behavior. Although it can be easily conceived that the Cr₃C₂-NiCr coating microstructure evolution after high temperature exposure will depend on the as-sprayed microstructure and spraying parameters, very little has been done in this regard. This study intends to develop a better understanding of the effect of spraying parameters on the resulting chromium carbide coating microstructure after high temperature operation and high temperature sliding wear properties. The microstructures of different coatings produced from two morphologies of Cr₃C₂-NiCr powders and under a window of in-ﬂight particle temperature and velocity values were characterized through x-ray diffraction and scanning electron microscopy. Sliding wear at 800ºC was performed and the wear behavior correlated with the spraying parameters and coating microstructure. Vickers microhardness (300 gf) of the coatings before and after sliding wear was also measured.
Keywords: Chromium carbide; high temperature wear; HVOF; microstructure; sliding wear testing; spray parameters

Nurses' perceptions and attitudes towards new ADU technology and use - Sirois, Pascal; Fournier, Helene; Lebouthilier, Annette; Guerette-Daigle, Lise; Robichaud, Suzanne; Leblanc-Cormier, Gaetane; Molyneaux, Heather; O'Donnell, Susan; Mather, Lyndsay (Technology and Health Care, 2013)
BACKGROUND: The introduction of a new technology in hospitals – Automated Dispensing Units (ADUs) –aims to contribute to more secure, safe, efficient and cost effective health services. Several studies highlight the beneficial effects of similar technologies as well as their cost-savings potential but there is little literature exploring nurses’ perceptions and attitudes towards technology acceptance and the impact on technology use in a healthcare unit. OBJECTIVE: This research aimed to explore nurses’ perceptions and attitudes towards current technology use on their units and towards the introduction of ADU technology and use with nursing staff in two different hospitals in South-East New-Brunswick, Canada. METHODS: Semi-structured interviews were realized with the collaboration of nursing staff from two hospitals which were in urban and rural settings, prior to the introduction of ADUs in hospital wards. RESULTS: Findings in this study highlight the fact that missing medications (i.e., doses not available in cart) are inherently related to the completion of nursing staff’s medication distribution routine. Missing doses cause delays in medication delivery which may increase the occurrence of medication errors. Participants described current technology use as an intricate part of their routine. The latter is mainly utilized for patient monitoring and information retrieval. Overall, interview data indicated that ADU technology introduction is positively perceived by nursing staff particularly if the technology reduces missing doses events. CONCLUSIONS: Findings in this study underscore important concerns expressed by nursing staff regarding ADU technology integration into the current medication process and its impact on time management. Pre-implementation training and technical support were identified as important factors in facilitating technology acceptance and proper technology use.
Keywords: new technology; healthcare; medication distribution

The detailed scattering density profile model of PG bilayers as determined by molecular dynamics simulations, and small-angle neutron and x-ray scattering experiments - Kucerka, Norbert; Holland, Bryan; Pan, Jianjun; Heberle, Frederick A.; Gray, Chris G.; Tomberli, Bruno; Katsaras, John (Biophysical Journal, 2013)

Molecular structure of phosphatidylglycerol bilayers : fluid phase lipid areas and bilayer thicknesses as a function of temperature - Pan, Jianjun; Heberle, Frederick; Kucerka, Norbert; Tristram-Nagle, Stephanie; Szymanski, Michelle; Koepfinger, Mary; Katsaras, John (Biophysical Journal, 2013)
We have determined bilayer structural parameters of commonly used phosphatidylglycerols (PGs) in the fluid phase, by simultaneously analyzing small-angle neutron and X-ray scattering data. We report the temperature dependence of bilayer parameters obtained using the scattering density profile (SDP) model, including the area per lipid and overall bilayer thickness, as well as various intrabilayer structural parameters (e.g. hydrocarbon region thickness). Lipid areas were found to be larger than their neutral phosphatidylcholine (PC) counterparts, which is likely due to electrostatic repulsion of PG headgroups. In general, PG and PC bilayers show a similar response to changes in temperature and chain length, but a differential effect is observed with regard to chain unsaturation: the inclusion of a double bond in a PG lipid results in a smaller change in bilayer area and thickness than for the corresponding PC lipid. The extrapolated molecular area of saturated PG lipids at infinite chain length is similar to that of PC and PE, indicating the pivotal role of the glycerol-carbonyl backbone in shaping the lipid-water interface.

Evolution of strain and microstructure during creep of wrought AE42 and ZE10 magnesium alloys - Fletcher, M.; Sebert-Timmer, A.; Bichler, L.; Sediako, D. (Transactions of the Indian Institute of Metals, 2013)
Wrought magnesium alloys have been extensively used in the aerospace, electronics and automotive industries, where component weight is of concern and ambient temperatures remain below 100 °C. Undesirable creep relaxation of the wrought alloys above this temperature has been generally attributed to grain boundary sliding and plastic deformation leading to intergranular failure. The objective of this study was to investigate the compressive creep performance and microstructure of two wrought magnesium alloys (AE42 and ZE10) developed for high temperature applications. The total deformation of the AE42 and ZE10 alloys was 2.4 and 0.2 %, respectively, after 24 h creep test at 175 °C and 50 MPa. The poor creep performance of the AE42 alloy was explained via neutron diffraction studies which revealed that the elastic compressive response of (101 ¯ 0),(101 ¯ 1)and(21 ¯ 1 ¯ 0) planes was significantly more anisotropic in the AE42 than in the ZE10 alloy. Further, microstructural analysis revealed ~10 % increase in grain size due to creep, with additional (101 ¯ 2) and (112 ¯ 1) twinning in the AE42 alloy. Precipitation of β-Mg17Al12 phase in the AE42 alloy possibly contributed to grain boundary sliding and high plastic strain during creep testing.

Cognitive modelling of early music reading skill acquisition for piano : a comparison of the Middle-C and Intervallic methods - Emond, Bruno; Comeau, Gilles (Cognitive Systems Research, 2013)
In the classical music tradition, knowing how to read music is an essential skill and is seen as a fundamental component to develop when learning to play the piano. This research’s focus is to study the possible impact of two different teaching approaches to the acquisition of initial reading skills. By using cognitive modeling, we are hoping to observe through computer simulation the problem solving and decision-making tasks involved in decoding a simple musical score. Our model intends to capture a novice initial coordination of music reading and motor operations on a piano keyboard. As such, it does not aim at modelling advanced sight-reading skills. The paper introduces the Middle-C and Intervallic methods followed by a description of an ACT-R cognitive model and simulation results upon learning with each of the reading methods. Inspection of the simulation results reveals differences in terms of declarative memory and cognitive processing demands. In particular, the Intervallic method requires a larger number of declarative knowledge related to notes, and more execution planning than the Middle-C method.
Keywords: music reading; Middle-C method; Intervallic method; computer simulation; ACT-R

A fuzzy logic-based approach to uncertainty treatment in the rule interchange format: from encoding to extension - Zhao, Jidi; Boley, Harold; Dong, Jing (Uncertainty Reasoning for the Semantic Web II : International Workshops URSW 2008-2010 Held at ISWC and UniDL 2010 Held at FLoC, Revised Selected Papers, 2013)
The Rule Interchange Format (RIF) is a W3C recommendation that allows rules to be exchanged between rule systems. Uncertainty is an intrinsic feature of real world knowledge, hence it is important to take it into account when building logic rule formalisms. However, the set of truth values in the RIF Basic Logic Dialect (RIF-BLD) currently consists of only two values (t and f), although the RIF Framework for Logic Dialects (RIF-FLD) allows for more. In this paper, we first present two techniques of encoding uncertain knowledge and its fuzzy semantics in RIF-BLD presentation syntax. We then propose an extension leading to an Uncertainty Rule Dialect (RIF-URD) to support a direct representation of uncertain knowledge. In addition, rules in Logic Programs (LP) are often used in combination with the other widely-used knowledge representation formalism of the Semantic Web, namely Description Logics (DL), in many application scenarios of the Semantic Web. To prepare DL as well as LP extensions, we present a fuzzy extension to Description Logic Programs (DLP), called Fuzzy DLP, and discuss its mapping to RIF. Such a formalism not only combines DL with LP, as in DLP, but also supports uncertain knowledge representation.
Keywords: fuzzy logic; knowledge management; linked data; ontology learning; probability theory

Iterative classification for multiple target attributes - Guo, Hongyu; Létourneau, Sylvain (Journal of Intelligent Information Systems, 2013)
Many real-world applications require the simultaneous prediction of multiple target attributes. The techniques currently available for these problems either employ a global model that simultaneously predicts all target attributes or rely on the aggregation of individual models, each predicting one target. This paper introduces a novel solution. Our approach employs an iterative classification strategy to exploit the relationships among multiple target attributes to achieve higher accuracy. The computation scheme is developed as a wrapper in which many standard single-target classification algorithms can be simply “plugged-in” to simultaneously predict multiple targets. An empirical evaluation using eight data sets shows that the proposed method outperforms 1) an approach that constructs independent classifiers for each target, 2) a multitask neural network method, and 3) ensembles of multi-objective decision trees in terms of simultaneously predicting all target attributes correctly.
Keywords: multi-target learning; multitask learning; iterative classification; data mining

Face recognition using histograms of fuzzy oriented gradients - Salhi, Abdel Ilah; Kardouchi, Mustapha; Belacel, Nabil (Proceedings of International Conference on Computer Applications Technology ICCAT' 2013, 2013)
Efficient face descriptors require a careful equilibration between accuracy and feature dimension. In recent years Histogram of Oriented Gradient (HOG) starts to be used in the face recognition task. However the best recognition rate for HOG requires a high dimensional feature. In this paper, we will incorporate fuzzy concept to HOG aiming to achieve a good recognition rate with a low feature vector dimension. The proposed Histogram of Fuzzy Oriented Gradient will be applied to the face recognition task. Experimental results on ORL database show that HFOG outperforms the standard HOG in terms of recognition rate with a lower dimensional vector.
Keywords: fuzzy sets; HOG; HFOG; face recognition; feature dimension

State of the art review of inspection technologies for condition assessment of water pipes - Liu, Zheng; Kleiner, Yehuda (Measurement, 2013)
This paper reviews the state-of-the-art of inspection techniques and technologies towards condition assessment of water distribution and transmission mains. Pipe condition assessment is the determination of its current condition, including structural health, impact on water quality, and hydraulic capacity. The collection and analysis of relevant data and information is the first and a paramount step to detect and monitor critical indicators to prevent or mitigate catastrophic failures. The technologies include conventional non-destructive inspection and advanced sensor techniques for condition monitoring. This paper focuses on the inspection techniques and technologies for structural deterioration of water pipes. Technologies like smart pipe, augmented reality, and intelligent robots are also briefly discussed and summarized.
Keywords: Pipe condition assessment; Distress indicator; Deterioration; Non-destructive inspection

Practical correlations for the thermal resistance of vertical enclosed airspaces for building applications - Saber, Hamed H. (Building and Environment, 2013)
Many parts of the building envelope contain enclosed airspaces. The thermal resistance (R-value) of an enclosed airspace depends on the emissivity of all surfaces that bound the airspace, the size and orientation of the airspace, the direction of heat transfer through the airspace, and the respective temperatures of all surfaces that define the airspace. The 2009 ASHRAE Handbook of Fundamentals (Chapter 26) provides a table that contains the R-values for an enclosed airspace. The ASHRAE table is extensively used by modelers, architects and building designers in the design of building enclosures. This table provides R-values for enclosed airspaces for different values of the thickness of the airspace, effective emittance, mean airspace temperature, and temperature differences across the airspace. The effect of the airspace aspect ratio (height/thickness of airspace) on the R-value is not included in the ASHRAE table. However, in a recent study on the R-value of reflective insulations using a numerical simulation model, it was shown that the aspect ratio of the airspace can affect the R-value of the enclosed airspace. The numerical simulation model used in this study had been benchmarked against experimental data obtained using two standard test methods: ASTM C-518 and ASTM C-1363. In this paper, a numerical simulation study was conducted, that was based on previous work focused on enclosed airspaces, to investigate the effect of the aspect ratio on the R-value of vertical enclosed airspaces of different thicknesses and having a wide range of values for effective emittance, mean temperature, and temperature differences across the airspace. The R-values predicted from numerical simulation are compared with those provided in the ASHRAE table. Considerations were also given to investigating the potential increase in R-values of enclosed airspaces when a thin sheet is placed vertically in the middle of the airspace and whose surfaces have different values of emissivity. Finally, practical correlations are developed for determining the R-values of an enclosed airspace for future use by modelers, architects and building designers. The simplicity of these correlations suggests that these could be included in the ASHRAE Handbook of Fundamentals.
Keywords: Reflective insulation; furred-airspace assembly; low emissivity material; thermal modelling; thermal resistance test method; R-value; heat flow meter; ASTM C-518; ASTM C-1363; airflow; heat transfer by convection; conduction and radiation

Convective heat transfer correlations for low-profile spherical cavities with planar bottom surfaces (1415-RP) - Saber, Hamed H.; Laouadi, Abdelaziz; Galasiu, Anca D.; Arsenault, Chantal (HVAC and R Research, 2013)
Domed cavities are found in many building applications, such as conventional skylights and tubular daylighting devices. Heat transfer through domed cavities is thus an important parameter for evaluating the energy performance rating of such skylight systems and in calculating the heating and cooling loads of buildings. Although there have been many studies on the convective heat transfer in related geometries, there is a limited information on natural convective heat transfer in domed cavities with planar inner surfaces. In a previous study, numerical modeling was conducted on natural laminar convective heat transfer in horizontal high-profile domed cavities with planar inner surfaces. In this article, the previous study is extended to investigate the natural convective heat transfer in horizontal low-profile spherical cavities with planar inner surfaces. The bounding surfaces are subject to uniform temperature conditions. The numerical model is based on the finite-element method. The results show that for different boundary temperature conditions, the airflow in the cavities is mono-cellular and reaches steady-state conditions for both cold and hot weather conditions. The numerical results are used to develop practical correlations for the Nusselt number in terms of Rayleigh number.
Keywords: Heat transfer by conduction; convection and radiation; skylight devices; heat transfer correlations; Nusselt number; spherical cavities

Development of a graphite probe calorimeter for absolute clinical dosimetry - Renaud, James; Marchington, David; Seuntjens, Jan; Sarfehnia, Arman (Medical Physics, 2013)
The aim of this work is to present the numerical design optimization, construction, and experimental proof of concept of a graphite probe calorimeter (GPC) conceived for dose measurement in the clinical environment (U.S. provisional patent 61/652,540). A finite element method (FEM) based numerical heat transfer study was conducted using a commercial software package to explore the feasibility of the GPC and to optimize the shape, dimensions, and materials used in its design. A functioning prototype was constructed inhouse and used to perform dose to water measurements under a 6MV photon beam at 400 and 1000 MU/min, in a thermally insulated water phantom. Heat loss correction factors were determined using FEM analysis while the radiation field perturbation and the graphite to water absorbed dose conversion factors were calculated using Monte Carlo simulations. The difference in the average measured dose to water for the 400 and 1000 MU/min runs using the TG-51 protocol and the GPC was 0.2% and 1.2%, respectively. Heat loss correction factors ranged from 1.001 to 1.002, while the product of the perturbation and dose conversion factors was calculated to be 1.130. The combined relative uncertainty was estimated to be 1.4%, with the largest contributors being the specific heat capacity of the graphite (type B, 0.8%) and the reproducibility, defined as the standard deviation of the mean measured dose (type A, 0.6%). By establishing the feasibility of using the GPC as a practical clinical absolute photon dosimeter, this work lays the foundation for further device enhancements, including the development of an isothermal mode of operation and an overall miniaturization, making it potentially suitable for use in small and composite radiation fields. It is anticipated that, through the incorporation of isothermal stabilization provided by temperature controllers, a subpercent overall uncertainty will be achieved.
Keywords: graphite calorimetry; reference dosimetry; heat transfer modeling; proof of concept; absolute dosimetry

First report of Pn-Li₂MnSiO₄ synthesized by ion exchange - Duncan, Hugues; Kondamreddy, Abhinay; Mercier, Patrick H. J.; Le Page, Yvon; Abu-Lebdeh, Yaser; Couillard, Martin; Whitfield, Pamela S.; Davidson, Isobel J. (Batteries and Energy Technology (General) - 221st ECS Meeting, 2013)

Three-dimensional human shape inference from silhouettes: reconstruction and validation - Boisvert, Jonathan; Shu, Chang; Wuhrer, Stefanie; Xi, Pengcheng (Machine Vision and Applications, 2013)
Silhouettes are robust image features that provide considerable evidence about the three-dimensional (3D) shape of a human body. The information they provide is, however, incomplete and prior knowledge has to be integrated to reconstruction algorithms in order to obtain realistic body models. This paper presents a method that integrates both geometric and statistical priors to reconstruct the shape of a subject assuming a standardized posture from a frontal and a lateral silhouette. The method is comprised of three successive steps. First, a non-linear function that connects the silhouette appearances and the body shapes is learnt and used to create a first approximation. Then, the body shape is deformed globally along the principal directions of the population (obtained by performing principal component analysis over 359 subjects) to follow the contours of the silhouettes. Finally, the body shape is deformed locally to ensure it fits the input silhouettes as well as possible. Experimental results showed a mean absolute 3D error of 8 mm with ideal silhouettes extraction. Furthermore, experiments on body measurements (circumferences or distances between two points on the body) resulted in a mean error of 11 mm.
Keywords: human models; statistical prior; shape-from-silhouettes; three-dimensional reconstruction

Seasonal freeze resistance of rainbow smelt (Osmerus mordax) is generated by differential expression of glycerol-3 phospahte dehydrogenase, phosoenol pyruvate carboxykinase and antifreeze protein genes - Liebscher, Ryan S.; Richards, Robert C.; Lewis, Johanne M.; Short, Connie E.; Muise, Denise M.; Driedzic, William R.; Ewart, K. Vanya (Physiological and Biochemical Zoology, 2013)
In winter, rainbow smelt (Osmerus mordax) accumulate glycerol and produce an antifreeze protein (AFP), which both contribute to freeze resistance. The role of differential gene expression in the seasonal pattern of these adaptations was investigated. First, cDNAs encoding smelt and Atlantic salmon (Salmo salar) phosphoenolpyruvate carboxykinase (PEPCK) and smelt glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were cloned so that all sequences required for expression analysis would be available. Using quantitative PCR, expression of beta actin in rainbow smelt liver was compared with that of GAPDH in order to determine its validity as a reference gene. Then, levels of glycerol-3-phosphate dehydrogenase (GPDH), PEPCK, and AFP relative to beta actin were measured in smelt liver over a fall-winter-spring interval. Levels of GPDH mRNA increased in the fall just before plasma glycerol accumulation, implying a driving role in glycerol synthesis. GPDH mRNA levels then declined during winter, well in advance of serum glycerol, suggesting the possibility of GPDH enzyme or glycerol conservation in smelt during the winter months. PEPCK mRNA levels rose in parallel with serum glycerol in the fall, consistent with an increasing requirement for amino acids as metabolic precursors, remained elevated for much of the winter, and then declined in advance of the decline in plasma glycerol. AFP mRNA was elevated at the onset of fall sampling in October and remained elevated until April, implying separate regulation from GPDH and PEPCK. Thus, winter freezing point depression in smelt appears to result from a seasonal cycle of GPDH gene expression, with an ensuing increase in the expression of PEPCK, and a similar but independent cycle of AFP gene expression.
Keywords: antifreeze; proteins; gene expression regulation; genetics; glycerolphosphate; dehydrogenase; osmeriformes; osmeriformes metabolism; phosphoenolpyruvate; GTP; carboxykinase; seasons