Study of thin dielectric films for thermo-dielectric energy conversion Quarterly report, 1 Mar. - 31 May 1966

Thin dielectric films for thermo-dielectric energy conversio

Frozen-Plug Technique for Liquid-Oxygen Plumbing

A frozen-plug technique has been conceived as a means of temporarily blocking the flow of liquid oxygen or its vapor through a tube or pipe. The technique makes it possible to perform maintenance, repair, or other work on downstream parts of the cryogenic system in which the oxygen is used, without having to empty an upstream liquid-oxygen reservoir and, hence, without wasting the stored liquid oxygen and without subjecting the reservoir to the stresses of thermal cycling

Electronic structure, structural properties, and dielectric functions of IV-VI semiconductors: PbSe and PbTe

The electronic structure and frequency dependent dielectric function E(E) of rocksalt semiconductors PbSe and PbTe are investigated using the local density approximation (LDA) and the generalized gradient approximation as two different exchange and correlation approximations, within the full-potential linearized augmented plane-wave approach. Spin-orbit coupling has been incorporated in the study. The results are presented and compared with other recent calculations and experimental data. Structural properties are also obtained by means of calculations of total energy as a function of lattice parameters. The bulk structural parameters are sensitive to the choice of exchange and correlation approximation. The essential features of the band structure and density of states of PbSe and PbTe are reproduced by our calculations and agree quite well with available experimental results. The position of the minimum energy gap is correctly predicted, although the value of the gap is as usual, underestimated by the local density approximation with respect to the experimental data. This gap value is improved by the inclusion of the generalized gradient approximation. Also, we have calculated the real [E1(W)] and imaginary [E2(W)] parts of E(W) for both compounds, in the framework of the LDA scheme for exchange and correlation. The inclusion of spin-orbit coupling leads to a richer structure in both E1(W) and E2(W). The agreement with experimental results is satisfactory.Instituto de Física de Líquidos y Sistemas Biológico

Electronic structure, structural properties, and dielectric functions of IV-VI semiconductors: PbSe and PbTe

The electronic structure and frequency dependent dielectric function E(E) of rocksalt semiconductors PbSe and PbTe are investigated using the local density approximation (LDA) and the generalized gradient approximation as two different exchange and correlation approximations, within the full-potential linearized augmented plane-wave approach. Spin-orbit coupling has been incorporated in the study. The results are presented and compared with other recent calculations and experimental data. Structural properties are also obtained by means of calculations of total energy as a function of lattice parameters. The bulk structural parameters are sensitive to the choice of exchange and correlation approximation. The essential features of the band structure and density of states of PbSe and PbTe are reproduced by our calculations and agree quite well with available experimental results. The position of the minimum energy gap is correctly predicted, although the value of the gap is as usual, underestimated by the local density approximation with respect to the experimental data. This gap value is improved by the inclusion of the generalized gradient approximation. Also, we have calculated the real [E1(W)] and imaginary [E2(W)] parts of E(W) for both compounds, in the framework of the LDA scheme for exchange and correlation. The inclusion of spin-orbit coupling leads to a richer structure in both E1(W) and E2(W). The agreement with experimental results is satisfactory.Instituto de Física de Líquidos y Sistemas Biológico

Editorial review: Male circumcision, gender and HIV prevention in sub-Saharan Africa: a (social science) research agenda

No Abstract.SAHARA J Vol. 4 (3) 2007: pp. 658-66

Maternal Health Outcomes and Male Partner Involvement Among HIV Infected Women in Rural South Africa

Introduction This study aimed to investigate the association between Male Partner Involvement (MPI) and maternal health outcomes among women attending Prevention of Mother-to-Child Transmission of HIV (PMTCT) services in rural South Africa. The association between Male Partner Participation in the main study (MPP) and maternal health outcomes among these women was also investigated. Methods The study utilized data collected from 535 HIV infected women in a randomized controlled trial between 2015 and 2016. Maternal health outcome data (delivery mode, pregnancy systolic and diastolic blood pressure, pregnancy body mass index, pregnancy CD4 count, and pregnancy viral load) were collected from the women's antenatal record forms accessed from the primary healthcare facilities. Bivariate and multivariable logistic regression models were used to estimate the association between socio-demographic characteristics of the women, MPI, and MPP with maternal health outcomes. Results The mean age of the women was 29.03 years (SD = 5.89). No significant associations were found between MPI and any of the maternal health outcomes contrary to what was hypothesized. Both the bivariate and multivariate analysis indicated a significant association between MPP and higher pregnancy viral load, contrary to the study hypothesis. Insignificant associations were found between MPP and both pregnancy CD4 count and pregnancy blood pressure. The only significant association between maternal health outcomes and socio-demographic characteristics, was between educational attainment and higher pregnancy CD4 count in both the bivariate and multivariate analysis. Conclusion for Practice The study showed no significant support for MPI in improving maternal health outcomes of women in PMTCT in rural South Africa. Future studies should include additional maternal health outcomes for investigation

Report and policy brief: 2nd Annual Conference on Social Aspects of HIV/AIDS Research, Cape Town, 9 - 12 May 2004

This report and policy brief summarises the overarching principles, key findings and suggested policy options that emerged from rapporteur reports of conference proceedings of the 2nd Annual Conference on Social Aspects of HIV/AIDS Research, Cape Town, 9 - 12 May 2004. SAHARA-J (2004) 1(2): 62-77 Keywords: SAHARA Network, Conference proceedings, Policy brief, HIV, AIDS, Sub-Saharan Africa, reseach, Social aspects. RÉSUMÉ Ce dossier de rapport et de politique présente un compte-rendu des principes dominants, des conclusions principales et des options d'une politique proposée qui font partie des communications présentées de la 2è Conférence Annuelle de Recherche sur les Aspects Sociaux du VIH/SIDA, le Cap, 9 - 12 mai 2004. SAHARA-J (2004) 1(2): 62-77 Mots clés: Réseau du SAHARA, démarches de conférence, dossier de politique, HIV/AIDS, Afrique Secondaire-Saharan, reseach, aspects sociaux