62 resultados para Yielding


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Objective: To be used in conjunction with 'Pharmacological management of unipolar depression' [Malhi et al. Acta Psychiatr Scand 2013;127(Suppl. 443):6-23] and 'Lifestyle management of unipolar depression' [Berk et al. Acta Psychiatr Scand 2013;127(Suppl. 443):38-54]. To provide clinically relevant recommendations for the use of psychological treatments in depression derived from a literature review. Method: Medical databases including MEDLINE and PubMed were searched for pertinent literature, with an emphasis on recent publications. Results: Structured psychological treatments such as cognitive behaviour therapy and interpersonal therapy (IPT) have a robust evidence base for efficacy in treating depression, even in severe cases of depression. However, they may not offer benefit as quickly as antidepressants, and maximal efficacy requires well-trained and experienced therapists. These therapies are effective across the lifespan and may be preferred where it is desired to avoid pharmacotherapy. In some instances, combination with pharmacotherapy may enhance outcome. Psychological therapy may have more enduring protective effects than medication and be effective in relapse prevention. Newer structured psychological therapies such as mindfulness-based cognitive therapy and acceptance and commitment therapy lack an extensive outcome literature, but the few published studies yielding positive outcomes suggest they should be considered options for treatment. Conclusion: Cognitive behaviour therapy and IPT can be effective in alleviating acute depression for all levels of severity and in maintaining improvement. Psychological treatments for depression have demonstrated efficacy across the lifespan and may present a preferred treatment option in some groups, for example, children and adolescents and women who are pregnant or postnatal. © 2013 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

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Deformation twinning plays an important role in the yielding of extruded magnesium alloys, especially when loaded in compression along the extrusion axis. The magnitude of this contribution is not accurately known. The present study employs electron backscatter diffraction to reveal the influence of grain orientation on twin-volume fraction for alloy AZ31 tested in compression to strains between 0.008 and 0.015. For these strains, it is seen that approximately 45 pct of the deformation can be attributed to "tensile" twinning. The variation of twin-volume fraction over different orientation classes correlates closely with the maximum Schmid factors for both tensile twinning and basal slip. These effects are readily explained quantitatively using a mean field crystal plasticity model without recourse to stochastic effects. Encouraged by this, we introduce an analytical approximation based on the uniformity of (axial) work. © 2013 The Minerals, Metals & Materials Society and ASM International.

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 A material model for more effective analysis of plastic deformation of sheet materials is presented in this paper. The model is capable of considering the following aspects of plastic deformation behavior of sheet materials: the anisotropy in yielding stresses in different directions by using a quadratic yield function (based on Hill’s 1948 model and stress ratios), the anisotropy in work hardening by introducing non-constant flow stress hardening in different directions, the anisotropy in plastic strains in different directions by using a quadratic plastic potential function and non-associated flow rule (based on Hill’s 1948 model and plastic strain ratios, r-values), and finally some of the cyclic hardening phenomena such as Bauschinger’s effect and transient behavior for reverse loading by using a coupled nonlinear kinematic hardening (so-called Armstrong-Frederick-Chaboche model). Basic fundamentals of the plasticity of the model are presented in a general framework. Then, the model adjustment procedure is derived for the plasticity formulations. Also, a generic numerical stress integration procedure is developed based on backward-Euler method (so-called multistage return mapping algorithm). Different aspects of the model are verified for DP600 steel sheet. Results show that the new model is able to predict the sheet material behavior in both anisotropic hardening and cyclic hardening regimes more accurately. By featuring the above-mentioned facts in the presented constitutive model, it is expected that more accurate results can be obtained by implementing this model in computational simulations of sheet material forming processes. For instance, more precise results of springback prediction of the parts formed from highly anisotropic hardened materials or that of determining the forming limit diagrams is highly expected by using the developed material model.

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Plastic yielding in magnesium alloys frequently involves the initiation of both slip and twinning events. A proper understanding of the phenomenon at the grain level requires knowledge of how these two mechanisms progress and interact over both time and space and what the local resolved stresses are. To date, simultaneous collection of such information has not been achievable. To address this shortfall, we have developed a modified Laue based in situ micro X-ray diffraction technique with an unprecedented combination of time and spatial resolution. A ten-fold reduction in data collection times is realized by the refinement of rapid polychromatic Laue "single-shot" mapping. From single Laue patterns, we extract grain depth information, detect onset of yielding and achieve 2 × 10-4 lattice strain resolution. The technique is employed to examine yielding and twinning in a magnesium grain embedded ∼200 μm below the sample surface. We examine 13 time steps and reveal the following behaviour: initial onset of basal slip, subsequent onset of twinning, development of further accommodation slip and evolution of twin shape and size; along with the corresponding values of local resolved shear stresses. © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

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The performance of curtain flow chromatography column technology with MS detection was evaluated for the analysis of labile compounds. The curtain flow column design allows for separations that are faster and/or more sensitive than conventional columns, depending on how exactly the curtain flow column is configured. For example, when mass spectral detection is employed, the curtain flow column can yield separations that are 5-times faster than conventional columns when the curtain flow and the conventional columns have the same internal diameter. Or when the internal diameter of the conventional column is reduced in order to yield the same analytical through-put as the curtain flow column, the sensitivity on the curtain flow column can be as much as 66-fold higher than the conventional column. As a consequence of the higher analytical through-put less standardization is required in the analysis of labile compounds because less sample degradation is apparent. Consequently the sample integrity is preserved yielding data of a higher quality.

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Prospective observational studies uniformly link vitamin D deficiency with the incidence of type 2 diabetes mellitus (T2DM), yet trials supplementing participants at risk of T2DM with vitamin D to reduce progression to T2DM have yielded inconsistent results. Inconsistencies between supplementation trials may be due to insufficient dosing or small sample sizes. Observational studies may also have reported spurious associations due to uncontrolled confounding by lifestyle or genetic factors. Alternatively, observational and intervention studies may not be entirely comparable. Observational studies show an association between higher vitamin D status, which is predominantly derived from sun exposure, and decreased incidence of T2DM. Trials intervene with vitamin D supplementation, and therefore may be missing alternate causes of the effect of sun exposure, as seen in observational studies. We propose that sun exposure may be the driving force behind the associations seen in observational studies; sun exposure may have additional benefits beyond increasing serum 25-hydroxyvitamin D (25OHD) levels. We performed an electronic literature search to identify articles that examined associations between sun exposure and T2DM and/or glucose metabolism. A best evidence synthesis was then conducted using outcomes from analyses deemed to have high methodological quality. Ten eligible full-text articles were identified, yielding 19 T2DM-related outcomes. The best evidence analysis considered 11 outcomes which were grouped into six outcome types: T2DM, fasting glucose, glucose tolerance, fasting insulin, insulin secretion and insulin sensitivity. There was moderate evidence to support a role of recreational sun exposure in reducing odds of T2DM incidence. High-level evidence was lacking; evidence presented for other outcomes was of low or insufficient level. This review highlights significant gaps in research pertaining to sun exposure and T2DM-related outcomes. Further research is encouraged as we aim to identify novel preventative strategies for T2DM.

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 Noncontact detection characteristic of Doppler radar provides an unobtrusive means of respiration detection and monitoring. This avoids additional preparations, such as physical sensor attachment or special clothing, which can be useful for certain healthcare applications. Furthermore, robustness of Doppler radar against environmental factors, such as light, ambient temperature, interference from other signals occupying the same bandwidth, fading effects, reduce environmental constraints and strengthens the possibility of employing Doppler radar in long-term respiration detection, and monitoring applications such as sleep studies. This paper presents an evaluation in the of use of microwave Doppler radar for capturing different dynamics of breathing patterns in addition to the respiration rate. Although finding the respiration rate is essential, identifying abnormal breathing patterns in real-time could be used to gain further insights into respiratory disorders and refine diagnostic procedures. Several known breathing disorders were professionally role played and captured in a real-time laboratory environment using a noncontact Doppler radar to evaluate the feasibility of this noncontact form of measurement in capturing breathing patterns under different conditions associated with certain breathing disorders. In addition to that, inhalation and exhalation flow patterns under different breathing scenarios were investigated to further support the feasibility of Doppler radar to accurately estimate the tidal volume. The results obtained for both experiments were compared with the gold standard measurement schemes, such as respiration belt and spirometry readings, yielding significant correlations with the Doppler radar-based information. In summary, Doppler radar is highlighted as an alternative approach not only for determining respiration rates, but also for identifying breathing patterns and tidal volumes as a preferred nonwearable alternative to the conventional - ontact sensing methods.

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 This paper further the investigation of Doppler radar feasibility in measuring the flow in and out due to inhalation and exhalation under different conditions of breathing activities. Three different experiment conditions were designed to investigate the feasibility and consistency of Doppler radar which includes the combination of the states of normal breathing, deep breathing and apnoea state were demonstrated. The obtained Doppler radar signals were correlated and compared with the gold standard medical device, spirometer, yielding a good correlations between both devices. We also demonstrated the calibration of the Doppler radar signal can be performed in a simple manner in order to have a good agreements with the spirometer readings. The measurement of the flow in and out during the breathing activities can be measured accurately under different dynamics of breathing as long as the calibration is performed correctly.

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Successful amination of 4-bromo-1,8-naphthalimides with 'lengthy' imide N-functionality has been achieved using a general palladium mediated approach (conventional thermal protocols were sub-optimal). Only readily available Pd/ligand combinations were considered and the resulting Buchwald-Hartwig procedure using Pd2(dba)3, Xantphos and Cs 2CO3 is high yielding, relatively mild (40-80 °C, 24 h, yields 50-90%), requires only a modest excess of amine (3.0 equiv) and works equally well with other imide N-substituents. As such, the protocol complements existing methods but is superior for more complex substrates. Herein we compare this Pd mediated approach to the methods most commonly used and further demonstrate its utility by synthesising a number of new, highly fluorescent, 4-aminonaphthalimides. © 2014 Elsevier Ltd. All rights reserved.

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Alcohol misuse has been linked to negative organizational outcomes, including reduced productivity and increased absenteeism. Additionally, media reports have focused on alcohol misuse within sporting organizations. Given the paucity of research evaluating alcohol misuse interventions in professional sporting organizations, two systematic literature searches were conducted. Review one examined alcohol interventions in the workplace, and Review two included sport as a search term. Resultant papers demonstrated four categories of workplace alcohol interventions; brief, web based, psychosocial, and random drug and alcohol testing. Brief interventions were prevalent, yielding largely non-significant results. Review two studies evaluated a community sporting intervention, which adopted an ecological, multi-level approach, yielding significant improvements in alcohol consumption, drink-driving, and club profitability. Brief interventions in workplaces were ineffective, and no brief interventions were found in elite sporting organizations. However, community sporting interventions showed promising results. Ongoing evaluation of alcohol interventions in professional sporting organizations are recommended.

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Through Voltaire’s novella Candide, this essay examines the differences between a scientific and a religious mindset and the consequences of poor decision-making when a political leader has a religious mindset that he misapplies to fundamentally scientific questions. By analyzing various decisions that President Bush has made, it is argued that he has a religious mindset that has resulted in several fallacious choices of extreme import, yielding considerable losses. As such, a decision-maker with power should be able to distinguish questions best answered with a scientific mindset from those that are in the realm of philosophy or religion and apply a scientific mindset to the former. A scientific mindset formulates a theory that yields testable propositions, it acquires data and uses that to evaluate the verity of the theory. As the data contradict the theory’s predictions, the theory is adjusted. The religious mindset proffers certain explanations but then holds steadfastly to them. It ignores contrary evidence, does not adjust its tenets, or alter its prescribed behaviors, attacks the integrity of those who espouse contrarian viewpoints, and commits logical falla- cies, such as inverting the causative relationship.

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Nanoindentation was performed in selected grain orientations close to [. 112-0] and [. 101-0] in magnesium alloy Mg-3Al-1Zn. The atomic force microscopy (AFM) and electron backscatter diffraction (EBSD) were used to examine the nanoindentation imprint. Two critical events, yielding and pop-in were observed in the depth-load curves. Slip trace analysis suggests that basal slip is responsible for yielding. The following pop-in events at higher loads are associated with the appearance {. 101-2} twins on the surface. The critical resolved shear stress (CRSS) was estimated to be in the range of 220-400. MPa for the initiation of basal slip.

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Objectives: This paper assesses the impact of working less than or more than standard full-time hours on mental health, as well as possible differences in this relationship by gender and skill level. Methods: The study design was a longitudinal cohort with 12 annual waves of data collection over the period 2001-2012, yielding a sample of 90 637 observations from 18 420 people. Fixed effects within-person regression was used to control for time invariant confounding. The Mental Component Summary of the Short Form 36 (SF-36) measure was used as the primary outcome measure. Working hours over the preceding year was measured in five categories with standard full-time hours (35-40 h/week) as the reference. Results: Results indicated that when respondents were working 49-59 h (-0.52, 95% CI -0.74 to -0.29, p<0.001) and 60 h or more (-0.47, 95% CI -0.77 to -0.16, p=0.003) they had worse mental health than when they were working 35-40 h/week (reference). The difference in mental health when working 49-59 h was greater for women than for men. There were greater declines in mental health in relation to longer working hours among persons in higher compared to lower occupational skill levels. Conclusions: Study results suggest the need for employers and governments to regulate working hours to reduce the burden of mental ill health in the working population.

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Binary and ternary nanocomposites were produced by incorporating, via melt compounding, two types of octa-and dodecaphenyl substituted polyhedral oligomeric silsesquioxanes (POSS), montmorillonite (MMT), and combinations of POSS with MMT into nylon 6. The tensile, flexural, and dynamic thermo-mechanical properties of these materials were characterized and their structure-property relationships discussed. The results show that the losses in ductility and toughness experienced after inclusion of MMT into nylon 6 can be balanced out by co-mixing MMT with the dodecaphenyl- POSS to produce a ternary nanocomposite. This trend however was less pronounced in the ternary MMT/octaphenyl-POSS system. Analysis of the microstructure organization in these materials using XRD and SEM sheds some light on understanding the differences in behavior. Both types of POSS particles mixed alone in nylon 6 were found to be polydisperse (500 nm to a few microns in size) and locally aggregated, yielding materials with similar mechanical performance. The co-mixing of MMT with the octaphenyl- POSS served to break down the POSS crystal aggregates, enhancing their micro-mechanical reinforcing action. On the other hand, the POSS crystals were not affected in the MMT/dodecaphenyl-POSS system, which led to improving their toughening ability.

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Colleges are the product of colonial government policies that established and support mainstream educational models. Eurocentric perspective dominates all aspects of these institutions and is frequently un-yielding to Indigenous perspectives, values and educational approaches. This thesis outlines the transformation change of one College to incorporate and honour the Indigenous paradigm.