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Fikretoglu D.,Defense Research and Development Canada | Fikretoglu D.,McGill University | Liu A.,McGill University
Social Psychiatry and Psychiatric Epidemiology | Year: 2015

Purpose: Despite the availability of efficacious treatments, few individuals with a new-onset mental disorder access treatment in a timely manner. While barriers to mental health treatment have been studied among prevalent cases, few studies have focused specifically on incident cases. The purpose of the current study was to examine the prevalence and correlates of perceived barriers to mental health treatment among incident cases. Methods: Data came from the Canadian Community Health Survey, cycle 1.2 (CCHS 1.2), which represents a nationally representative sample of 36,984 Canadians. We used descriptive analyses to estimate the prevalence of different types of perceived barriers to treatment and logistic regression analyses to estimate the association between potential correlates and the probability of endorsing each type of barrier. Results: The most frequently reported type of barrier was acceptability. Coping efficacy and psychological well-being were negatively associated with the likelihood of reporting accessibility barriers. Education was negatively associated with reporting acceptability barriers but positively associated with reporting availability barriers. Conclusions: Among individuals with a recent disorder onset, acceptability barriers are the most frequently reported. Perceived accessibility barriers may be open to influence from current clinical functioning and current perceptions of internal coping resources. These findings contribute to an important discussion about the complexity of pathways to care and point to the need for comprehensive approaches to overcoming barriers to care. © 2014, Her Majesty the Queen in Right of Canada as represented by: Department of National Defence.

Liu H.,University of Western Ontario | Zhang Y.,University of Western Ontario | Li R.,University of Western Ontario | Sun X.,University of Western Ontario | Abou-Rachid H.,Defense Research and Development Canada
Journal of Nanoparticle Research | Year: 2012

Nitrogen-doped carbon nanotubes (CN x tubes) with nitrogen content of 7.6 at.% are synthesized on carbon papers. Thermal and chemical stability of the nanotubes are investigated by thermogravimetric analysis, differential scanning calorimetry and X-ray photoelectron spectroscopy techniques. The results indicate that the nitrogen can be firmly kept in the nanotubes after annealing at 300 °C in air. Under an argon atmosphere, the nitrogen would not release until 670°C, and half of the nitrogen incorporated is released after annealing at 700°C for 30 min. Chemical stability investigation indicates that the nitrogen incorporated in the nanotubes is very stable under the thermal and acid environment comparable to working condition of proton exchange membrane (PEM) fuel cells. Profile of the nitrogen species inside the nanotubes reveals that graphite-like nitrogen releases slower than any other kind of nitrogen in the nanotubes during the chemical stability measurement. These CN x tubes synthesized by this simple chemical vapor deposition method are expected to be suitable for many applications, such as PEM fuel cells that work under both thermal and corrosive conditions and some other mild thermal environments. © 2012 Springer Science+Business Media B.V.

Bacciochini A.,University of Ottawa | Radulescu M.I.,University of Ottawa | Yandouzi M.,University of Ottawa | Maines G.,University of Ottawa | And 2 more authors.
Surface and Coatings Technology | Year: 2013

The present study deals with the use of the Cold Gas Dynamic Spray (Cold Spray) process to consolidate reactive materials with low porosity (up to 99.8% of the theoretical maximum density) and controllable shapes for potential near-net shape applications. The study focuses on the Al/CuO thermite mixture. The microstructure and mechanical properties (four-point bending and microhardness) of the consolidated samples were investigated while varying the spray process parameters, such as stand-off distance, propellant gas pressure and feedstock powder (fuel) particle size. The reactive mixture was successfully consolidated without the onset of the thermite reaction. The consolidated sample reactivity was addressed through flame propagation velocity measurements as a function of sample density. Results show a relation between the sample's porosity level and the flame propagation velocity. The reduction of porosity tends to decrease the flame speed from approximately 1400. mm/s at 20% density down to 150. mm/s at 100%. This indicates a transition from convection dominated energy transfer at low porosities to heat conduction dominated mechanism at vanishing porosities when gas percolation is not possible. © 2013 Elsevier B.V.

Liu H.,University of Western Ontario | Zhang Y.,University of Western Ontario | Li R.,University of Western Ontario | Sun X.,University of Western Ontario | Abou-Rachid H.,Defense Research and Development Canada
Particuology | Year: 2011

Well aligned nitrogen-doped carbon nanotubes (CNx-NTs), as energetic materials, are synthesized on a silicon substrate by aerosol-assisted chemical vapor deposition. Tungsten (W) and molybdenum (Mo) metals are respectively introduced to combine with iron (Fe) to act as a bimetallic co-catalyst layer. Correlations between the composition and shape of the co-catalyst and morphology, size, growth rate and nitrogen doping amount of the synthesized CNx-NTs are investigated by secondary and backscattered electron imaging in a field emission scanning electron microscope (FESEM) and X-ray photoelectron spectrometer (XPS). Compared to pure iron catalyst, W-Fe co-catalyst can result in lower growth rate, larger diameter and wider size distribution of the CNx-NTs; while incorporation of molybdenum into the iron catalyst layer can reduce the diameter and size distribution of the nanotubes. Compared to the sole iron catalyst, Fe-W catalyst impedes nitrogen doping while Fe-Mo catalyst promotes the incorporation of nitrogen into the nanotubes. The present work indicates that CNx-NTs with modulated size, growth rate and nitrogen doping concentration are expected to be synthesized by tuning the size and composition of co-catalysts, which may find great potential in producing CNx-NTs with controlled structure and properties. © 2011 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences.

Liu Z.,National Research Council Canada | Mrad N.,Defense Research and Development Canada
IEEE Sensors Journal | Year: 2013

The application of structural health monitoring (SHM) often employs multiple sensors to monitor the state of health and usage of the structures. The fault of any sensor may lead to an inaccurate or even incorrect inference with the collected sensor data, which will accordingly create a negative impact on higher-level decisions for maintenance and services. Thus, sensor validation becomes a critical process to the performance of the whole SHM system. This paper presents the use of Bayesian belief network to validate the reading of strain gauges on an aluminum plate for loading monitoring. The Bayesian belief network is constructed with the training data. The factors investigated in this paper, which may affect the validation process, include sensor configuration, sensor redundancy, and sensor data range for the discretization. The feasibility of using a Bayesian belief network for SHM sensor validation is demonstrated with the experimental results. © 2001-2012 IEEE.

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