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

On the design of multimedia software and future system architectures

A principal challenge for reducing the cost for designing complex systems-on-chip is to pursue more generic systems for a broad range of products. For this purpose, we explore three new architectural concepts for state-of-art video applications. First, we discuss a reusable scalable hardware architecture employing a hierarchical communication network fitting with the natural hierarchy of the application. In a case study, we show that MPEG streaming in DTV occurs at high level, while subsystems communicate at lower levels. The second concept is a software design that scales over a number of processors to enable reuse over a range of VLSI process technologies. We explore this via an H.264 decoder implementation scaling nearly linearly over up to eight processors by applying data partitioning. The third topic is resource-scalability, which is required to satisfy realtime constraints in a system with a high amount of shared resources. An example complexity-scalable MPEG-2 coder scales the required cycle budget with a factor of three, in parallel with a smooth degradation of quality

Use of insecticide-treated bednets in an urban coastal area of Puducherry, India: A cross-sectional study

Use of Insecticide-Treated Bednets (ITNs) has been shown to reduce the incidence of mosquito-borne diseases. However, the impact of ITNs depends on its community acceptance. We studied the ITN usage and factors influencing it, following the distribution of one ITN to each family in an urban area of Puducherry. Around 93.6% of the 157 respondents surveyed were aware of mosquito-borne diseases. Coils and vaporizers were used in 91.1% of the families. Around two-fifths (41.3%) of the 116 families who received the ITNs used it regularly with another 5.1% using it irregularly. Majority of the users (85%) reported reduced mosquito bites and pleasant sleep after use. Small size of ITNs was the most common reason for non-use (46.3%). Families not using normal bed nets at the time of distribution of ITNs were unlikely to use ITNs at present (odds ratio = 5.22, P < 0.001). Therefore, ITN size should be increased and distribution in urban settings should accompany behavior change communication

Children's education and parental old-age health : Evidence from a population-based, nationally representative study in India

Previous research has documented intergenerational transmission of human capital from children to parents. Less is known, however, about heterogeneity in this 'upward transmission' in low-resource settings. We examine whether co-resident adult children's education is associated with improved health among older parents in India, using nationally representative data from the 2014 Indian National Sample Survey. Parents of children with tertiary education had a lower probability of reporting poor health than parents of children with less than primary education. The benefits of children's education persisted after controlling for economic factors, suggesting that non-pecuniary pathways-such as health knowledge or skills-may play an important role. The association was more pronounced among economically dependent parents and those living in the North and West regions. Taken together, our results point to a strong positive association between children's education and parental health, the role of non-pecuniary pathways, and the importance of subnational heterogeneity in India