Development of Prototype Pixellated PIN CdZnTe Detectors

We report initial results from the design and evaluation of two pixellated PIN Cadmium Zinc Telluride detectors and an ASIC-based readout system. The prototype imaging PIN detectors consist of 4X4 1.5 mm square indium anode contacts with 0.2 mm spacing and a solid cathode plane on 10X10 mm CdZnTe substrates of thickness 2 mm and 5 mm. The detector readout system, based on low noise preamplifier ASICs, allows for parallel readout of all channels upon cathode trigger. This prototype is under development for use in future astrophysical hard X-ray imagers with 10-600 keV energy response. Measurements of the detector uniformity, spatial resolution, and spectral resolution will be discussed and compared with a similar pixellated MSM detector. Finally, a prototype design for a large imaging array is outlined.Comment: 10 pages Latex, 9 figures, to appear in Proc. of SPIE Vol. 3446 "Hard X-ray and Gamma-Ray Detector Physics and Applications

Limited Common Origins of Multiple Adult Health-Related Behaviors: Evidence from U.S. Twins

Health-related behaviors are significant contributors to morbidity and mortality in the United States, yet the empirical evidence on the underlying causes of the vast within-population variation in health-related behaviors is mixed. While many potential causes of behaviors have been identified—such as schooling, genetics, and environments—little is known on how much of the variation across multiple health-related behaviors is due to a common set of causes. We use three separate datasets on U.S. twins to investigate the degree to which multiple health-related behaviors correlate and can be explained by a common set of factors. Based on the results of both within identical twin regressions and multivariate behavioral genetic models, we find that aside from smoking and drinking, most behaviors are not strongly correlated among individuals. While we find some evidence that schooling may be related to smoking, schooling is not a strong candidate explanation for the covariation between multiple behaviors. Similarly, we find that a large fraction of the variance in each of the behaviors is consistent with genetic factors; however, we do not find strong evidence that a single common set of genes explains variation in multiple behaviors. We find, however, that a large portion of the correlation between smoking and heavy drinking is consistent with common, mostly childhood, environments–suggesting that the initiation and patterns of these two behaviors might arise from a common childhood origin. Research and policy to identify and modify this source may provide a strong way to reduce the population health burden of smoking and heavy drinking

High efficiency cadmium and zinc telluride-based thin film solar cells

Polycrystalline Cd{sub 1-x}Zn{sub x}Te and Cd{sub 1-x}Mn{sub x}Te films with a band gap of 1.7 eV were successfully grown on glass/SnO{sub 2}/CdS substrates by molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD), respectively. Polycrystalline Cd{sub 1-x}Zn{sub x}Te films grown by MBE resulted in uniform composition and sharp interfaces. However, polycrystalline Cd{sub 1-x}Mn{sub x}Te films grown by MOCVD showed nonuniform compositions and evidence of manganese accumulation at the Cd{sub 1-x}Mn{sub x}Te/CdS interface. We found that manganese interdiffuses and replaces cadmium in the CdS film. By improving the CdTe/CdS interface and, thus, reducing the collection function effects, the efficiency of the MOCVD CdTe cell can be improved to about 13.5%. MBE-grown CdTe cells also produced 8%--9% efficiencies. The standard CdTe process was not optimum for ternary films and resulted in a decrease in the band gap. Recent results indicate that CdCl{sub 2} + ZnCl{sub 2} chemical treatment may prevent the band-gap reduction, and that chromate etch (rather than bromine etch) may provide the solution to contact resistance in the ternary cells

Economic Globalization, Nutrition and Health: a review of quantitative evidence

BACKGROUND: Unhealthy dietary patterns have in recent decades contributed to an endemic-level burden from non-communicable disease (NCDs) in high-income countries. In low- and middle-income countries rapid changes in diets are also increasingly linked to malnutrition in all its forms as persistent undernutrition and micronutrient deficiencies continue to coexist with a rising prevalence of obesity and associated NCDs. Economic globalization and trade liberalization have been identified as potentially important factors driving these trends, but the mechanisms, pathways and actual impact are subject to continued debate. METHODS: We use a ‘rigorous review’ to synthesize evidence from empirical quantitative studies analysing the links between economic globalization processes and nutritional outcomes, with a focus on impact as well as improving the understanding of the main underlying mechanisms and their interactions. FINDINGS: While the literature remains mixed regarding the impacts of overall globalization, trade liberalization or economic globalization on nutritional outcomes, it is possible to identify different patterns of association and impact across specific sub-components of globalization processes. Although results depend on the context and methods of analysis, foreign direct investment (FDI) appears to be more clearly associated with increases in overnutrition and NCD prevalence than to changes in undernutrition. Existing evidence does not clearly show associations between trade liberalization and NCD prevalence, but there is some evidence of a broad association with improved dietary quality and reductions in undernutrition. Socio-cultural aspects of globalization appear to play an important yet under-studied role, with potential associations with increased prevalence of overweight and obesity. The limited evidence available also suggests that the association between trade liberalization or globalization and nutritional outcomes might differ substantially across population sub-groups. Overall, our findings suggest that policymakers do not necessarily face a trade-off when considering the implications of trade or economic liberalization for malnutrition in all its forms. On the contrary, a combination of nutrition-sensitive trade policy and adequate regulation of FDI could help reduce all forms of malnutrition. In the context of trade negotiations and agreements it is fundamental, therefore, to protect the policy space for governments to adopt nutrition-sensitive interventions

Hydrological Study of Tanks in an Urban Sub-Basin

In urban areas, tanks are the major means for harvesting surface water as most of the land surfaces are found to be paved. But these tanks experience significant decrease in their water spread area and storage capacity owing to rapid urbanization. Thus, hydrological study of these tanks would serve as an effective key to monitor, conserve and maintain them effectively. Manimangalam tank along with cluster of tanks located in the upstream catchment of Adyar river basin, Tamil Nadu has been selected for the study. SCS-CN method has been used for estimating the daily runoff volume generated. The land use-land cover map (LULC) for certain years before and after the onset of urbanization process has been prepared using the satellite images and GIS tools. The overlay analysis was carried out with the LULC map and hydrologic soil map and unique hydrologic response units were identified. The weighted curve number was calculated for antecedent moisture conditions I, II and III respectively. The initial abstractions and daily runoff occurring within the individual tank catchments were calculated for the selected years between 1980 and 2017. The impact of urbanization on the rainfall – runoff processes over the years that have taken place within the study area has been assessed