Gamma Radiation Induced Effects in TeO2 Thin Films

Gamma radiation induced effects on electrical and optical properties of thin films of tellurium dioxide (TeO2), a wide band gap semiconductor material, of different thicknesses prepared by thermal evaporation method have been studied in detail. The current-voltage characteristics for the thin films before and after gamma irradiation were analysed to obtain normalised current versus gamma dose plots at different applied voltages. The plots obtained clearly show that the normalised current increases almost linearly with the radiation dose up to certain limit and this limit is found to be dependent on thickness of the thin film. Beyond this limit the current is found to decrease. For gamma sources emitting higher gamma energy, this linear behaviour extends to higher radiation doses. The optical characterization of the as-deposited thin films as well as gamma irradiated thin films clearly shows that the optical band gap decreases with increase in the gamma radiation dose up to a certain limit. However, the optical band gap has been found to increase beyond this limit. The observed changes in electrical and optical properties clearly indicate the possibility of using TeO2 thin film as a gamma radiation dosimeter. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3101

Electron-photon scattering mediated by localized plasmons: A quantitative analysis by eigen-response theory

We show that the scattering interaction between a high energy electron and a photon can be strongly enhanced by different types of localized plasmons in a non-trivial way. The scattering interaction is predicted by an eigen-response theory, numerically verified by finite-difference-time-domain simulation, and experimentally verified by cathodoluminescence spectroscopy. We find that the scattering interaction associated with dark plasmons can be as strong as that of bright plasmons. Such a strong interaction may offer new opportunities to improve single-plasmon detection and high-resolution characterization techniques for high quality plasmonic materials.Comment: 4 pages, 4 figures (excluding Supporting Information

Access to condoms for female sex workers in Andhra Pradesh.

BACKGROUND: Condoms are an essential part of comprehensive HIV prevention and care programmes. We report the accessibility of male condoms for female sex workers (FSWs) and the associated characteristics that may play a major role in determining access to condoms for FSWs. METHODS: Confidential interviews of 6509 street- and home-based FSWs in 13 districts of the Indian state of Andhra Pradesh provided data on the number of paying clients and various aspects of access to free condoms and purchase of condoms. Access to condoms was defined as having ever obtained condoms either through free distribution or through purchase. Multivariate analyses were done separately for street- and home-based FSWs to describe correlates of their access to condoms. The requirement of condoms was assessed based on the number of paying clients during the past 15 days. RESULTS: Data on condom access were available for 6465 (99.3%) FSWs. A total of 2850 (44.1%; 95% CI: 36.2%-52.0%) reported accessing free condoms ever and 2336 (36.1%; 95% CI: 30.6%-41.6%) had purchased condoms ever (not mutually exclusive). The primary sources for condoms were non-governmental organization facilities (73.8%) and pharmacies (79.7%) for free and purchased condoms, respectively. A total of 3510 (54.3%; 95% CI: 48.5%-60.1%) FSWs reported no access to free or purchased condoms during the past 15 days, and this no access was significantly higher for those > 30 years of age, with no schooling, street-based FSWs, and with no participation in a FSW support group (p < 0.001 for each in univariate analysis). Participation in a FSW support group was the main predictor of access to free condoms for both types of FSWs during the past 15 days with multivariate analysis. Condom requirements during the past 15 days were met for 67.5% of FSWs who had accessed only free condoms and for 33.8% of those who had accessed only purchased condoms. CONCLUSIONS: One-fourth of FSWs had never accessed condoms, and a little over half of those who had ever accessed reported no access during the past 15 days. Condom requirements were not met for three-fifths of the FSWs. HIV prevention programmes need to Increase access to free condoms for FSWs in Andhra Pradesh as access to condoms is a necessary prerequisite for condom use