Characterization of grain boundaries in CdTe polycrystalline films

CdTe polycrystalline films with the average size of grains within the range 10…360 μm were grown on sapphire substrates by using the modified close-spaced sublimation technique. Transverse (across the film) and lateral (along the film’s surface) conductivity as a function of bias voltage and temperature were measured using appropriate arrangement of contacts. The transverse conductivity exhibits ohmic behavior, whereas the lateral transport of carriers is dominated by potential barriers at the grain boundaries. The carrier concentration in the grains and the potential barrier height have been estimated. The inhomogeneous distribution of deep defects through the grains was found from the photoluminescence measurements

Search of the radio emission from flare stars at decameter wavelengths

Observations of the two M-dwarf flare stars (AD Leonis and EV Lacertae), which were carried out with the radio telescope UTR-2 (Kharkiv, Ukraine) in the range of 16.5 − 33 MHz, are presented. 167 events of radio emission from AD Leo and 73 events from EV Lac were detected in the period of 2010-2011. These events were considered as stellar emission in ON-OFF regime of observations. The morphology of the probable events in the form of bursts from flare stars is considered and frequency drift rates, durations and uxes of the bursts are analysed

Decametric radio bursts associated with the 13 July 2004 CME event at frequencies 10–30 MHz

We report on the observations of solar type IV burst and its precursors on the 13 of July 2004 at frequencies 10 − 30 MHz. The radio telescope UTR-2 observational data compiled from SOHO, WIND, NDA, RHESSI, GOES data were used. The main properties (frequency drift rate, duration, flux) of type IV burst and its precursors, namely solar type III and type II bursts, are analysed. We consider the type IV burst connected with appearance of the coronal mass ejection, which occurrence coincides with the type IV burst beginning. Several physical characteristics of this CME were estimated

Frequency drift rates of powerful decameter Type III bursts

We report on the observations of powerful (fluxes are larger than 10⁻¹⁹ W m⁻² Hz⁻¹) solar Type III bursts at frequencies 10 − 30 MHz. Recordings of 163 bursts, observed in July 2002 and of 231 bursts observed in August 2002 are investigated. The main properties of these Type III bursts (frequency drift rate, duration, flux, frequency bandwidth) are analyzed. In present report we pay more attention to consideration of frequency drift rate. A great difference between the observed and the well-known empirical frequency dependencies of Type III bursts drift rate is determined. A linear approximation for the drift rate versus frequency is found. It indicates, that solar corona above active regions has exponential density distribution. We consider that drift rate value depends on the position of an active region on the solar disc

Accretion, Outflows, and Winds of Magnetized Stars

Many types of stars have strong magnetic fields that can dynamically influence the flow of circumstellar matter. In stars with accretion disks, the stellar magnetic field can truncate the inner disk and determine the paths that matter can take to flow onto the star. These paths are different in stars with different magnetospheres and periods of rotation. External field lines of the magnetosphere may inflate and produce favorable conditions for outflows from the disk-magnetosphere boundary. Outflows can be particularly strong in the propeller regime, wherein a star rotates more rapidly than the inner disk. Outflows may also form at the disk-magnetosphere boundary of slowly rotating stars, if the magnetosphere is compressed by the accreting matter. In isolated, strongly magnetized stars, the magnetic field can influence formation and/or propagation of stellar wind outflows. Winds from low-mass, solar-type stars may be either thermally or magnetically driven, while winds from massive, luminous O and B type stars are radiatively driven. In all of these cases, the magnetic field influences matter flow from the stars and determines many observational properties. In this chapter we review recent studies of accretion, outflows, and winds of magnetized stars with a focus on three main topics: (1) accretion onto magnetized stars; (2) outflows from the disk-magnetosphere boundary; and (3) winds from isolated massive magnetized stars. We show results obtained from global magnetohydrodynamic simulations and, in a number of cases compare global simulations with observations.Comment: 60 pages, 44 figure

Activation of the surface of steel by impact treatment

Translated from Russian (Fiz. Khim. Obrab. Mater. 1988 v. 22(2) p. 74-78)Available from British Library Document Supply Centre- DSC:9023.19(VR-Trans--4056)T / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

The main stages of image-processing in the development of biotechnical systems in medical radiology

В статье рассмотрены этапы обработки медицинских радиологических изображений: фильтрация, предварительная обработка, сегментация и этап принятия решения. В работе предложена модернизация оператора Собеля, а также представлены результаты работы некоторых методов сегментации на реальных радиологических изображениях. Работа ведется совместно с государственным учреждением «Институт медицинской радиологии им. С.П. Григорьева Национальной академии медицинских наук Украины».У статті розглянуто етапи обробки медичних радіологічних зображень: фільтрація, попередня обробка, сегментація і етап ухвалення рішення. В роботі запропонована модернізація оператора Собеля, а також представлені результати роботи деяких методів сегментації на реальних радіологічних зображеннях. Робота ведеться спільно з державною установою «Інститут медичної радіології ім. С.П. Григор'єва Національної академії медичних наук України».This article reviews such stages as: filtration, preprocessing, segmentation and decision-making stage. Еhe modernization of Sobel operator and the results of some segmentation methods in the real radiological images are presented in this work. The work is conducted jointly with the state institution "Institute of Medical Radiology named after S.P. Grigoriev National Academy of Medical Sciences of Ukraine". Figs: 4. Refs: 8 titles

Influence of hot-dip aluminising on properties of structural steels

15.00; Translated from Russian (Stal' 1987 (9) p. 87-89)SIGLEAvailable from British Library Document Supply Centre- DSC:9022.06(BISI-Trans--26439)T / BLDSC - British Library Document Supply CentreGBUnited Kingdo