99 research outputs found
LaF3 insulators for MIS structures
Thin films of Laf3 deposited on Si or GaAs substrates have been observed to form blocking contacts with very high capacitances. This results in comparativelyâhysteresisâfree and sharpCâV (capacitanceâvoltage) characteristics for MIS structures. Such structures have been used to study the interface states of GaAs with increased resolution and to construct improved photocapacitive infrared detectors
Contraceptive Use and Method Preference among Women in Soweto, South Africa: The Influence of Expanding Access to HIV Care and Treatment Services
Objective: Preventing unintended pregnancy among HIV-positive women constitutes a critical and cost-effective approach to primary prevention of mother-to-child transmission of HIV and is a global public health priority for addressing the desperate state of maternal and child health in HIV hyper-endemic settings. We sought to investigate whether the prevalence of contraceptive use and method preferences varied by HIV status and receipt of highly active antiretroviral therapy (HAART) among women in Soweto, South Africa. Methods: We used survey data from 563 sexually active, non-pregnant women (18â44 years) recruited from the Perinatal HIV Research Unit in Soweto (MayâDecember, 2007); 171 women were HIV-positive and receiving HAART (median duration of use = 31 months; IQR = 28, 33), 178 were HIV-positive and HAART-naĂŻve, and 214 were HIV-negative. Medical record review was conducted to confirm HIV status and clinical variables. Logistic regression models estimated adjusted associations between HIV status, receipt of HAART, and contraceptive use. Results: Overall, 78 % of women reported using contraception, with significant variation by HIV status: 86 % of HAART users, 82 % of HAART-naĂŻve women, and 69 % of HIV-negative women (p,0.0001). In adjusted models, compared with HIVnegativ
Correction to: Evaluating the impact of Marie Stopes Internationalâs digital family planning counselling application on the uptake of long-acting and permanent methods of contraception in Vietnam and Ethiopia: a study protocol for a multi-country cluster randomised controlled trial.
Following publication of the original article [1], the authors requested a correction to be made, indicating L. Bates as the first author only. There is no joint first authorship
The role of policy in influencing farm household behaviour in european mountain areas
Bel F., Dax Thomas, Herrmann Vera, Knickel K., Seiber O., Shucksmith Mark, Veuthey F. The role of policy in influencing farm household behaviour in european mountain areas. In: Revue de géographie alpine, tome 81, n°2, 1993. pp. 101-127
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Uncertainty of Pyrometers in a Casting Facility
This work has established uncertainty limits for the EUO filament pyrometers, digital pyrometers, two-color automatic pyrometers, and the standards used to certify these instruments (Table 1). If symmetrical limits are used, filament pyrometers calibrated in Production have certification uncertainties of not more than {+-}20.5 C traceable to NIST over the certification period. Uncertainties of these pyrometers were roughly {+-}14.7 C before introduction of the working standard that allowed certification in the field. Digital pyrometers addressed in this report have symmetrical uncertainties of not more than {+-}12.7 C or {+-}18.1 C when certified on a Y-12 Standards Laboratory strip lamp or in a production area tube furnace, respectively. Uncertainty estimates for automatic two-color pyrometers certified in Production are {+-}16.7 C. Additional uncertainty and bias are introduced when measuring production melt temperatures. A -19.4 C bias was measured in a large 1987 data set which is believed to be caused primarily by use of Pyrex{trademark} windows (not present in current configuration) and window fogging. Large variability (2{sigma} = 28.6 C) exists in the first 10 m of the hold period. This variability is attributed to emissivity variation across the melt and reflection from hot surfaces. For runs with hold periods extending to 20 m, the uncertainty approaches the calibration uncertainty of the pyrometers. When certifying pyrometers on a strip lamp at the Y-12 Standards Laboratory, it is important to limit ambient temperature variation (23{+-}4 C), to order calibration points from high to low temperatures, to allow 6 m for the lamp to reach thermal equilibrium (12 m for certifications below 1200 C) to minimize pyrometer bias, and to calibrate the pyrometer if error exceeds vendor specifications. A procedure has been written to assure conformance
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