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. We analyzed a 40-year set of multicolor photometry and a 15-year set of synoptic monitoring of SS 433 along with fragmentary spectral and radio data. This system contains a neutron star and an A3–A7 I giant. The system is found to be either close, in contact, or it has a common envelope from time to time. The A-type giant is now in transition to the dynamical mass transfer.
The X-ray binary Her X-1 consists of an accreting neutron star and the optical companion HZ Her. The 35-day X-ray variability of this system is known since its discovery in 1972 by the UHURU satellite and is believed to be caused by forced precession of the warped accretion disk tilted to the orbital plane. We argue that the observed features of the optical variability of HZ Her can be explained by free precession of the neutron star with a period close to that of the forced disk precession. The model parameters include a) the intensity (power) of the stream of matter flowing out of the optical star; b) the X-ray luminosity of the neutron star; c) the optical flux of the accretion disk; d) the X-ray irradiation pattern on the donor star; e) the tilt of the inner and outer edge of the accretion disk. A possible synchronization mechanism based on the coupling between the neutron star free precession and the dynamical action of non-stationary gas streams is discussed shortly.
This study examines how to stop the pyrolysis of fir needles, birch leaves, aspen twigs and their mixture using the minimum volumes of water. The combustion of forest fuels is suppressed by spraying water on their surface. The temperature of thermal decomposition is monitored throughout the layer of forest fuel by thermocouples. A high-speed camera and optical techniques allow us to study water spraying and its interaction with forest fuels. Finally, the study specifies the ranges of the minimum water volumes and the times of ending of the thermal decomposition of forest fuels. When analyzing the energy balance in the thermally decomposing forest fuel, a mathematical expression is formulated to predict the water volume sufficient to suppress thermal decomposition of forest fuel. This expression takes into account the ratio between the heat energy spent on water evaporation in pores of forest fuel and the heat energy of the reacting layer of forest fuel. The obtained dimensionless factor considers the main parameters of water spraying and the properties of forest fuel. This factor enables us to apply the research findings to forest fuel in various regions of the world.
The paper presents peculiarities of organization and performance of activities on disposition of the high level activity radwaste repository located at the radwaste disposal site of the Russian Research Center “Kurchatov Institute” in Moscow. The process of the radwaste extraction from the repository is described in comparison with similar activities in other old repositories. Tools and equipment used for the radwaste extraction from the repository are listed. Conventional construction machines equipped with a hydraulic hammer or a clamshell were used for destruction of the concrete-encased radwaste mass and extraction of low-level radwaste. Intermediate- and high-level radwaste was extracted by remotely controlled robots operating inside the shielding structure. Gamma visor was used for detection of high-level radwaste or fragments in the mass concrete being destroyed and for pointing remotely controlled robots accordingly. The paper describes peculiarities of radiation monitoring in the course of operations on disposition of the repository. For rapid detection of changes in radiation conditions in the working areas, there was used a gamma locator with on-line transmission of its data to a PC and their processing. The same measuring and extraction equipment were used for remediation of high-level radwaste repository at the Gas Plant complexes.
Single-wall carbon nanotubes have been synthesized, purified, attested with a high resolution electron microscopy and Raman scattering and deposited by liquid electrophoresis onto different substrates (including a metallized glass) to produce the effective and homogeneous film cathodes for low-field electron emitters. The emission properties (a threshold of the emission switching on, a current value, a time-stability) of the SWNT cathodes have been investigated. A prototype of a phosphorescent lamp with a nanotube cathode has been designed. The Raman spectra of the SWNT cathode registered in situ from the shining lamp have shown no temperature increase and time-degradation of the nanotube material during the emission process.
We have developed multipurpose spectral technique for amplitude and phase measurements at frequencies 100–1000 GHz based on the use of backward wave oscillators (BWOs) as sources of probing radiation. It utilizes to the utmost all the remarkable advantages of BWOs such as high radiation intensity, monochromaticity, polarization, as well as high speed and wide range of frequency tuning. Extremely simple and flexible open-space measurement geometries are used. The developed technique seems to be the most appropriate and promising for the reliable, precise and mass characterization of materials and devices at millimeter-submillimeter waves.
The non-catalytical chemical vapor deposition (CVD) method was used to grow carbon thin film material consisting of plate-like nanosized graphite crystallites and multiwall carbon nanotubes with predominant orientation of both species by their crystallographic plane, corresponding to a graphite basal plane, along a normal to the film surface. A number of experimental techniques was used for examination and characterization of the film phase composition, morphology, and electron properties peculiarities. Low-field electron emission with highly density of emission sites and emission current was obtained for the film material and allow to demonstrate their applicability for sealed prototypes of light-emitting devices.
Recent measurements of the thermoelectric transport properties of a series of the half- Heusler compound ZrNiSn are presented. These materials are known to be bandgap intermetallic compounds with relatively large Seebeck coefficients and semimetallic to semiconducting transport properties. This makes them attractive for study as potential candidates for thermoelectric applications. In this study, trends in the thermoelectric power, electrical conductivity and thermal conductivity are examined as a function of chemical substitution on the various fcc sub-lattices that comprise the half-Heusler crystal structure. These results suggest that the lattice contribution to the thermal conductivity may be reduced by increasing the phonon scattering via chemical substitution. The effects of these substitutions on the overall power factor and figure-of-merit will also be discussed.
A method for solving the Navier–Stokes equations in domains with moving boundaries is proposed. By means of a coordinate transformation, the region under consideration is converted to a region with known boundaries which are coordinate surfaces. An appropriate difference scheme with an algorithm for its implementation is constructed. The method is applied to the case of steady incompressible viscous flow past a resting deformable bubble. Results are obtained for wide ranges for Reynolds and Weber numbers and compared with other theoretical or experimental works in the common regions for the governing parameters. A separation of the flow and the occurrence of a toroidal vortex in the rear of the bubble is observed and verified through a number of computations. Typical flow patterns as well as a variety of practically important relations between the parameters of the flow are shown graphically.
At the close of the last century there began to spread in the field of psychiatry the idea that every specific pathological agent and every individual toxin produced a picture of psychological disorder that was uniquely characteristic of the causative agent. This idea was extensively developed in the work of Kraepelin (1892) and supplanted the view expressed earlier by Morel, who denied the existence of any specificity in psychological disorders related to their aetiology.
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