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

Study of the 10 micron continuum of water vapor

Radiation attenuation by atmospheric water vapor is considered. A formula based on laboratory data is recommended for approximating continuous absorption in the spectra region in question. Data of full scale measurements and laboratory experiments are compared. It was concluded that only molecular absorption need be taken into account under clear atmospheric conditions during the warm part of the year, while in winter or in cloudy conditions, the effect of aerosol can be significant

Analytical-numerical methods of calculations of energy and three-dimensional particle distributions in electromagnetic cascades

Analytical and numerical methods of calculation of the energy and three dimensional EPS characteristics are reported. The angular and lateral functions of electrons in EPS have been obtained by the Landau and small angle approximations A and B and compared with earlier data. A numerical method of solution of cascade equations for the EPS distribution function moments has been constructed. Considering the equilibrium rms angle as an example, errors appearing when approximating the elementary process cross sections by their asymptotic expressions are analyzed

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

History and philosophy of science course for international PhD students majoiring in engineering

PhD students` needs analysis is the starting point for the study in the course History and Philosophy of Science especially when the course is delivered in English. After successful course completion students develop generic skills based on critical thinking. The course content is sophisticated thus students` cultural background and professional aspirations matter for the course successful delivery

Synchronous PWM control of four inverters feeding asymmetrical six-phase motor drive

Novel method of space-vector-based pulsewidth modulation (PWM) has been disseminated for synchronous control of four inverters feeding six-phase drive on the base of asymmetrical induction motor which has two sets of windings spatially shifted by 30 electrical degrees. Basic schemes of synchronized PWM, applied for control of four separate voltage source inverters, allow both continuous phase voltages synchronization in the system and required power sharing between DC-sources. Simulations show a behavior of sixphase system with continuous and discontinuous versions of synchronized PWM

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

Basic schemes of synchronized pulsewidth modulation for cascaded inverters of drive system with two DC-sources

Continuous and discontinuous schemes of synchronized pulsewidth modulation (PWM) have been applied for control of an open-end winding motor drive fed by cascaded inverters supplied by two dc-sources with non-equal voltages. Simulations illustrate behavior of these systems with algorithms of synchronized PWM. Spectra of multilevel phase voltage of open-end winding motor drives with synchronized PWM do not contain even harmonics and sub-harmonics during the whole control range, which is especially important for the medium-power and high-power systems.Представлены результаты исследования и моделирования режимов работы системы электропривода на базе асинхронного электродвигателя с разомкнутыми обмотками, подключенными к сдвоенным инверторам напряжения с синхронной модуляцией непрерывного и прерывистого типа, питающихся от двух изолированных источников постоянного напряжения. Показано, что в спектре многоуровневого фазного напряжения подобных систем с алгоритмами синхронной широтно-импульсной модуляции на всем диапазоне регулирования отсутствуют четные гармоники и субгармоники, что представляется особенно важным для преобразовательных систем повышенной мощности.Представлено результати дослідження та моделювання режимів роботи системи eлектроприводу на базі асинхронного електродвигуна з розімкненими обмотками, які підключено до подвоєних інверторів напруги з синхронною модуляцією неперервного та пeреривчастого типу, що живляться від двох ізольованих джерел постійного струму. Показано, що у спектрі багаторівневої фазної напруги таких систем з алгоритмами синхронної широтно-імпульсної модуляції у всьому діапазоні регулювання відсутні парні гармоніки та субгармоніки, що є найважливішим для перетворювальних систем підвищеної потужност

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