1,728 research outputs found

    Channeling of electrons and positrons in straight and periodically bent diamond(110) crystals

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    In this paper we present the results of a systematic numerical analysis of the channeling properties of electrons and positrons in oriented straight and periodically bent diamond(110) crystals. We analyse dependence of the intensity of the radiation emitted on the projectile energy as well as on the bending amplitude. The analysis presented is based on the grounds of accurate numerical simulations of the channeling process. The simulation parameters, such as the crystal orientation, thickness and bending parameters of the crystals as well as the energy of the projectiles, were chosen to match those used in past and ongoing experiments. The peculiarities which appear in the radiation spectra are attributed to the interplay of various radiation mechanisms. The analysis performed can be used to predict and explain future experimental results.Comment: 14 pages, 8 figures, 1 tabl

    Experimental Confirmation of Avogadros Law for Thermal Radiation

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    Experimental study of pressure variation in metal empty sealed container in low vacuum conditions (0.1-10 mbar) for temperature range from 290 to 1490 K is presented. Three characteristic areas of pressure variation were registered: the pressure growth in accordance with Avogadros law in the temperature range from 290 to 700-800 K, the pressure drop in the temperature range from 800 to 1300 K and again the intensive pressure increasing in the temperature range from 1300 to 1490 K. Possible causes of registered pressure variation in sealed container with increasing temperature and then cooling to its original conditions were analyzed. One of the more active causes is thermal radiation action in metal empty sealed container

    Low-molecular components of colostrum as a regulator of the organism redox-system and biological antidote

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    The protein composition in the diapason of molecular masses from 4800 to 9500 Dа has been studied in colostrum, taken from different cows, and manifested the expressed biological activity. For this aim, an influence of low-molecular components of colostrum on some physiological parameters (change of body mass and temperature) at intoxication of animals (Wistar rats) by blue stone has been studied. An influence of colostrum low-molecular components on parameters of the organism redox-system (content of hyperperoxides of lipids and activity of glutathione peroxidase) in the blood serum of animals has been studied. For determining integral characteristics of colostrum components, electric conductivity of skim colostrum and one of colostrum with low-molecular proteins (less than 10 000 Dа), taken from different cows, were used. The aim of this work is to study interconnections of an influence of colostrum low-molecular proteins on models of organism intoxication by cooper ions. It is demonstrated, that the colostrum composition includes 25–35 different proteins with a molecular mass from 4800 to 9500 Dа. The number and ratio between protein fractions depend on individual physiological-biochemical characteristics of producers. It has been revealed, that there is no direct dependence between the protein content in a measuring cell (2 mg/ml, 4 mg/ml and 10 mg/ml) with skim colostrum and electric conductivity change, and this dependence is different for skim colostrum, taken from different cows. Individual differences are manifested both at electric conductivity change and by the content of colostrum low-molecular proteins in a measuring cell. It is demonstrated, that colostrum low-molecular components can eliminate the toxic effect of blue stone on the organism, which mechanisms are connected with a balance shift in the system “prooxidants↔antioxidants” towards antioxidants. The electric conductivity of colostrum components may be used as an express-method for evaluating biologically active substances of colostru

    Master Robotic Net

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    The main goal of the MASTER-Net project is to produce a unique fast sky survey with all sky observed over a single night down to a limiting magnitude of 19 - 20mag. Such a survey will make it possible to address a number of fundamental problems: search for dark energy via the discovery and photometry of supernovas (including SNIa), search for exoplanets, microlensing effects, discovery of minor bodies in the Solar System and space-junk monitoring. All MASTER telescopes can be guided by alerts, and we plan to observe prompt optical emission from gamma-ray bursts synchronously in several filters and in several polarization planes.Comment: 10 pages, 8 figure

    Investigation of vibratory drilling model with adaptive control. Part 2: mixed control of peak-to-peak vibration displacement and cutting continuity index

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    Chip segmentation is important condition for deep drilling efficiency improving. Chip segmentation could be ensured by sustaining stable axial self-excited vibrations of a drill. Vibrations are excited by regenerative effect when cutting edges move along the surface formed by previous passes. The conditions required for reliable chip segmentation could be created by using of a special vibratory head with an elastic element, providing tool additional axial flexibility. To maintain stable vibro-process with amplitude sufficient for chip segmentation, it’s suggested to use the vibratory head with a special actuator for adaptive feedback control proportional to a tool vibration velocity. Two algorithms of the feedback gain adaptation are proposed in the present paper: the adaptation by peak-to-peak displacement and the mixed adaptation by peak-to-peak displacement with cutting continuity index. The investigation of effectiveness of the proposed algorithms applicable to the model, described in [9], is also presented

    Radiation of high-energy electrons when channeling in the bent silicon and germanium monocrystals

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    In the paper, the simulation results on propagation of high-energy charged particles in the bent crystalline (Si and Ge) media have been presented within the atomistic approach. The calculation results were compared with literary experimental data obtained by measuring the output angular distribution of 855 MeV electrons with their very low initial divergence. Moreover, the literary experimental data on output radiation spectra for short bent Si and Ge crystals with different bending radii were taken into account. A good agreement between all the results was found
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