Gamma radiation exposure of MCT diode arrays

Investigations of electrical properties of long-wavelength infrared (LWIR) mercury cadmium telluride (MCT) arrays exposed to gamma-radiation have been performed. Resistance-area product characteristics of LWIR n{+}-p photodiodes have been investigated using microprobe technique at T=78 K before and after an exposure to various doses of gamma-radiation. The current transport mechanisms for those structures are described within the framework of the balance equation model taking into account the occupation of the trap states in the band gap.Comment: 11 pages, 4 figures, submitted to Semiconductor Science and Technolog

The IIASA-LUC Project Georeferenced Database of the Former USSR. Volume 5: Land Categories

The IIASA/LUC georeferenced database for the former U.S.S.R. was created within the framework of the project ``Modeling Land-Use and Land Cover Changes in Europe and Northern Asia" (LUC). For Russia, essential information on relief, soil, vegetation, land cover and use, etc. for routine environmental analysis was lacking when the LUC project started developing the database. In addition, the environmental data on the former U.S.S.R. which was available occurred in formats (papers, tables, etc.) that in general could not be used with modern information technology, and in particular in model building. In creating the LUC project database, we have achieved three objectives: 1) to obtain relevant information for the LUC project modeling exercises; 2) to develop data which are usable with modern information technology; 3) to contribute a series of digital databases which could be applied for various other analyses by the national and international scientific community. In defining the tasks it was agreed to create a set of digital databases which could be handled by geographic information systems (GIS). The full set of georeferenced digital databases was combined into the LUC project's GIS, using ARC/INFO. However, each individual item (physiography, soil, vegetation, etc.) was created as a unique specific digital database, allowing each item to be used separately, depending on users' needs. The complete series of these unique georeferenced digital databases for the territory of the former U.S.S.R. is described in the IIASA/LUC volumes: Volume 1 -- Physiography (landforms, slope conditions, elevations); Volume 2 -- Soil; Volume 3 -- Soil degradation status (Russia); Volume 4 -- Vegetation; Volume 5 -- Land categories; Volume 6 -- Agricultural regionalization

The IIASA-LUC Project Georeferenced Database of the former USSR. Volume 3: Soil Degradation Status in Russia

The IIASA/LUC georeferenced database for the former USSR (in part only for Russia), was created within the framework of the project "Modeling of Land Use and Land Cover Changes in Europe and Northern Asia" (LUC). For Russia, essential information on relief, soil, vegetation, land cover and use, etc. for routine environmental analysis was lacking when the LUC project first started developing the database. In addition, the environmental data on the former USSR which was available occurred in formats (papers, tables, etc.) that in general could not be used with modern information technology, and in particular in model building. In creating the LUC project database, we have established a threefold task: (1) to obtain the relevant information for the LUC project modeling exercises; (2) to develop data which is applicable to modern information technology; (3) to contribute a series of digital databases which could be applied for a number of other specific analysis by the national and international scientific community. In defining the tasks it was agreed to create a set of digital databases which could be handled by a geographic information systems (GIS). This required that the data had to be georeferenced. The complete set of georeferenced digital databases was combined into the LUC project's GIS, using ARC/INFO. However, each individual item (physiography, soil, vegetation, etc.) was created as an unique specific digital database, allowing to be used separately, depending on user's needs. The complete series of the unique georeferenced digital databases is described in several IIASA/LUC volumes: Volume 1 -- Physiography (land forms, slope conditions, elevations); Volume 2 -- Soil; Volume 3 -- Soil degradation status (Russia); Volume 4 -- Vegetation; Volume 5 -- Land categories; Volume 6 -- Agricultural regionalization

Environmental aspects of post-operational bioremediation of the typical municipal solid waste landfill of the administrative district

The article deals with the environmental consequences o f testing the method o f biological remediation o f the closed typical municipal solid waste landfill of the administrative district. The essence o f the method consists in the introduction of adapted composites from aboriginal, adapted or modified biological systems, primarily microorganisms for catalysis o f the decomposition process o f the organic component of waste landfills and subsequent separation o f valuable recyclable materials. The article presents the results o f the impact assessment o f a typical solid municipal waste landfil

Dual inverters with synchronized PWM for photovoltaic generation

Analysis of operation of photovoltaic system on the base of dual inverters with synchronized pulsewidth modulation (PWM), supplied by two strings of photovoltaic panels and connected to a grid by a three-phase transformer with the open winding configuration on primary side, has been performed. Algorithms of synchronized PWM are based in this case on continuous control of the switching frequencies of two inverters as function of magnitude of the DC-links voltage, providing both continuous voltage synchronization in each inverter and in the load, and also an improvement of operation of photovoltaic systems during solar irradiance fluctuation.Выполнен анализ работы фотоэлектрической преобразовательной системы на базе сдвоенных инверторов напряжения с синхронной широтно-импульсной модуляцией (ШИМ), питающихся соответственно от двух фотоэлектрических панелей и связанных с сетью через трехфазный трансформатор с разомкнутыми обмотками на первичной стороне. Алгоритмы синхронной ШИМ базируются на регулировании частоты коммутации двух инверторов в функции амплитуды питающего напряжения, обеспечивая при этом как непрерывную синхронизацию фазных напряжений инверторов и нагрузки, так и повышение эффективности функционирования фотопреобразовательной системы при флюктуациях солнечного излучения

Hybrid vehicle drive with synchronously modulated dual inverters

Analysis of operation of propulsion electric drive system with asymmetrical six-phase induction motor, supplied by the battery and fuel cells, has been performed. Power conversion part of the drive includes two neutral-point-clamped inverters, controlled by algorithms of synchronised pulsewidth modulation (PWM), providing both continuous phase voltage synchronization and common-mode voltage cancellation in the system.Выполнен анализ работы системы транспортного электропривода с шестифазным электродвигателем асимметричного типа, с автономным комбинированным электроснабжением от батареи и топливных элементов. Преобразовательная часть электропривода включает два инвертора напряжения со средней точкой в цепи источника питания, регулируемых на базе алгоритмов синхронной широтно-импульсной модуляции (ШИМ), обеспечивающих как непрерывную синхронизацию фазных напряжений, так и устранение напряжений нулевой последовательности в системе

Energy spectrum, density of states and optical transitions in strongly biased narrow-gap quantum wells

We study theoretically the effect of an electric field on the electron states and far-infrared optical properties in narrow-gap lead salt quantum wells. The electron states are described by a two-band Hamiltonian. An application of a strong electric field across the well allows the control of the energy gap between the two-dimensional (2D) states in a wide range. A sufficiently strong electric field transforms the narrow-gap quantum well to a nearly gapless 2D system, whose electron energy spectrum is described by linear dispersion relations \epsilon_{\sigma} (k) ~\pm (k-k_{\sigma}), where k_{\sigma} are the field-dependent 2D momenta corresponding to the minimum energy gaps for the states with spin numbers \sigma. Due to the field-induced shift of the 2D subband extrema away from k=0 the density of states has inverse-square-root divergencies at the edges. This property may result in a considerable increase of the magnitude of the optical absorption and in the efficiency of the electrooptical effect.Comment: Text 18 pages in Latex/Revtex format, 7 Postscript figure

Dislocations and defect structure around micro-indentations and Te precipitates in CdTe

N/

Efficacy of metformin for treatment and prevention of antipsychotic-induced overweight and obesity in women: an open-label, randomized, prospective placebo-controlled study

Background: The prevalence of obesity and metabolic abnormalities is increased patients with mental disorders receiving psychopharmacotherapy, which significantly impairs their treatment adherence.Aims: To evaluate the efficacy and safety of metformin in prevention and treatment obesity and overweight in patients with mental disorders receiving antipsychotics.Materials and methods: This was an open-label, prospective, randomized, placebo-controlled study of female patients with mental disorders (age, 18 to 50). The patients were randomized into two groups in a 2:1 ratio: the treatment group received metformin and the control group received placebo. Metformin was administered at a starting dose of 500 mg daily, with subsequent up-titration every 2 weeks when necessary, up to 2000 mg daily. The treatment duration was 6 months.Results: Baseline BMI in the treatment group (N=62) was 27,3 [24,0; 30,4] kg/m2; it decreased to 26,0 [22,5; 30,5] kg/m2, p < 0.0001, Wilсoxon test) after 6 months of treatment. The patients receiving metformin decreased their body weight by 3 [-6; 0] kg, or  -4,0 [-8; 0] %. In the placebo group (N=30), the baseline BMI was 27,5 [24,0; 32,0] kg/m2 and increased to 28,2 [25,8; 34,0] kg/m2 at 6 month (p=0.001, Wilсoxon test), or 3 [1; 6] kg. After 6 months of treatment, the difference in BMI between the metformin and placebo groups was significant (26,0 и 28,2 kg/m2, respectively, р=0,027, Mann-Withney test). Six (6) of 62 patients treated with metformin had side effects and were switched to an equivalent dose of prolonged release metformin, with reduction of side effects in 5 of them.Conclusions: The use of metformin in patients with mental disorders receiving antipsychotics allows for reduction or stabilization of body weight in 80% of cases, with ≥5% decrease of body weight in 44% of patients. It is recommended to start metformin at a dose of 500 mg daily with subsequent up-titration of up to 2000 mg if necessary