Time and spatial resolution of slip and twinning in a grain embedded within a magnesium polycrystal

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.

Improving quantification using curtain flow chromatography columns in the analysis of labile compounds: a study on amino acids.

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.

Shining the light on sunshine: a systematic review of the influence of sun exposure on type 2 diabetes mellitus-related outcomes

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.

Monitoring and analysis of respiratory patterns using microwave doppler radar

 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.

Non-contact measurement of respiratory function and deduction of tidal volume

 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.

Synthesis of 4-amino substituted 1,8-naphthalimide derivatives using palladium-mediated amination

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.

Alcohol misuse interventions in the workplace: a systematic review of workplace and sports management alcohol interventions

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.

Scientific and Religious Mindsets: A Candid Look at the Perils of a Panglossian President

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.

Distinguishing between slip and twinning events during nanoindentation of magnesium alloy AZ31

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.

Working hours and mental health in Australia: evidence from an Australian population-based cohort, 2001-2012

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.

Structure-property relationships in nylon 6 nanocomposites based on octaphenyl-, dodecaphenyl-POSS, montmorillonite, and their combinations

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.

Txeemsim and a journey of transformation— decolonizing post-secondary education

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.

Does disability status modify the association between psychosocial job quality and mental health? A longitudinal fixed-effects analysis

BACKGROUND: People with disabilities have difficulties in obtaining work. However, evidence suggests that those with disabilities derive substantial mental health benefits from employment. This paper assesses how the relationship between work and mental health is influenced by psychosocial job quality for people working with a disability. METHODS: The study design was a longitudinal cohort with 13 annual waves of data collection, yielding a sample of 122,883 observations from 21,848 people. Fixed-effects within-person regression was used to control for time invariant confounding. The Mental Component Summary (MCS) of the Short Form 36 (SF-36) measure was used as the primary outcome measure. The main exposure was a six-category measure of psychosocial job quality and employment status (including 'not in the labour force' [NILF] and unemployment). Disability status ('no waves of disability reported' and 'all contributed waves with reported disability') was assessed as an effect modifier. We also conducted a secondary analysis on respondents contributing both disability and non-disability waves. RESULTS: For those with no disability, the greatest difference in mental health (compared to optimal employment) occurs when people have the poorest quality jobs (-2.12, 95% CI -2.48, -1.75, p < 0.001). The relative difference in mental health was less in relation to NILF and unemployment (-0.39 and -0.66 respectively). For those with consistent disability, the difference in mental health when employed in an optimal job was similar between the poorest quality jobs (-2.25, 95% CI -3.84, -0.65, p = 0.006), NILF (-2.84, 95% CI -4.49, -1.20, p = 0.001) or unemployment (-2.56, 95% CI -4.32, -0.80, p = 0.004). These results were confirmed by the secondary analysis. CONCLUSIONS: Efforts to improve psychosocial job quality may have significant mental health benefits for people with disabilities. This will contribute to the economic viability of disability employment insurance schemes in Australia and other high-income countries.

Facile synthesis of guanidine functionalised building blocks

Three useful developments in the preparation of guanidines are presented herein. A collection of bis(Boc)aminoalkylguanidines (n=2, 3, 4 and 6; Boc=tert-butoxycarbonyl), known to be prone to cyclisation, have been synthesised and isolated without chromatography as shelf-stable sulfonate salts in good yield (up to 94%). Secondly, a selection of guanidines tethered to a range of other functional groups, including alkyne, alkene, alcohol, and azide, have been prepared in good yields with no requirement for a purification step, and thirdly an inexpensive, high-yielding (93%), and facile synthesis of N,N'-bis(Boc)guanidine, a key precursor for N,N'-bis(Boc)-N'-triflylguanidine, is described in which the need for chromatographic purification is again obviated.

Remoção de óleos emulsificados por flotação por ar dissolvido

Neste trabalho estuda-se o processo de flotação por ar dissolvido (FAD) como método de remoção de óleos emulsificados. Realizou-se uma revisão bibliográfica tanto do processo de flotação como dos fundamentos físico-químicos envolvidos na estabilidade e flotação de emulsões. Foram realizados testes de estabilidade de emulsões, de FAD descontínuos e contínuos, utilizando-se emulsões de 1000 mg/l de Óleo diesel e heptano. Verificou-se a eficiência do sulfato de alumínio e de compostos poliméricos como agentes desestabilizantes. Estudou-se a influência do tipo e concentração dos agentes desestabilizantes, pH da emulsão, do tipo de água e agitação nos testes de estabilidade como também na flotação por ar dissolvido. Os resultados obtidos indicaram a viabilidade técnica da aplicação do processo para a clarificação de efluentes oleosos atingindo valores de turbidez residual satisfatórios (menores que 5 UNT). O sulfato de alumínio mostrou-se mais eficiente como agente desestabilizante de ambas emulsões nos estudos de estabilidade e testes de PAD descontínuos, mas o polímero catiônico C-505 apresentou melhores resultados nos testes de flotação contínuos. O presente trabalho ainda apresenta um estudo de dimensionamento e do custo da unidade de FAD para remoção de óleos emulsificados que leva em consideração os custos de investimentos e de operação da unidade. Verifica-se que o custo total da unidade depende da vazão de alimentação, taxa de recirculação, taxa ar/sólido em massa e concentração inicial de óleos. Conclui-se que para as taxas de ar/sólido usados na indústria (geralmente menores que 0,1) o custo operacional do reagente é o parâmetro determinante do custo total atualizado da unidade. Isto faz com que o custo total atualizado seja essencialmente independente da relação taxa de aplicação - taxa ar/sólido.