1,586 research outputs found

    Casimir energy of finite width mirrors: renormalization, self-interaction limit and Lifshitz formula

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    We study the field theoretical model of a scalar field in presence of spacial inhomogeneities in form of one and two finite width mirrors (material slabs). The interaction of the scalar field with the defect is described with position-dependent mass term. Within this model we derive the interaction of two finite width mirrors, establish the correspondence of the model to the Lifshitz formula and construct limiting procedure to obtain finite self-energy of a single mirror without any normalization condition.Comment: 5 pages, based on the presentation on the Ninth Conference on Quantum Field Theory under the influence of External Conditions, Oklahoma, 200

    Second-layer nucleation in coherent Stranski-Krastanov growth of quantum dots

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    We have studied the monolayer-bilayer transformation in the case of the coherent Stranski-Krastanov growth. We have found that the energy of formation of a second layer nucleus is largest at the center of the first-layer island and smallest on its corners. Thus nucleation is expected to take place at the corners (or the edges) rather than at the center of the islands as in the case of homoepitaxy. The critical nuclei have one atom in addition to a compact shape, which is either a square of i*i or a rectangle of i*(i-1) atoms, with i>1 an integer. When the edge of the initial monolayer island is much larger than the critical nucleus size, the latter is always a rectangle plus an additional atom, adsorbed at the longer edge, which gives rise to a new atomic row in order to transform the rectangle into the equilibrium square shape.Comment: 6 pages, 4 figures. Accepted version, minor change

    The content and essence of education kinesiology

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    This work is devoted to the content and nature of educational kinesiology, its differences from the physical culture, sports kinesiology and applied kinesiolog

    Parity violating cylindrical shell in the framework of QED

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    We present calculations of Casimir energy (CE) in a system of quantized electromagnetic (EM) field interacting with an infinite circular cylindrical shell (which we call `the defect'). Interaction is described in the only QFT-consistent way by Chern-Simon action concentrated on the defect, with a single coupling constant aa. For regularization of UV divergencies of the theory we use % physically motivated Pauli-Villars regularization of the free EM action. The divergencies are extracted as a polynomial in regularization mass MM, and they renormalize classical part of the surface action. We reveal the dependence of CE on the coupling constant aa. Corresponding Casimir force is attractive for all values of aa. For aa\to\infty we reproduce the known results for CE for perfectly conducting cylindrical shell first obtained by DeRaad and Milton.Comment: Typos corrected. Some references adde

    Measurements of light background at large depth in the ocean

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    The mean intensity of Cerenkov emission from the products of K(40) decay and bioluminescence was measured at depths to 5 km. The intensity of ocean light background is found to depend upon depth and at the 5 km level is equal on averaged to 300 + or - 60 quanta/sq cms into spatial angle of 2 pi sterradian in transparency window. The amplitudes, duration and number of BL flashes were measured at various depths. The intensive flashes due to BL are shown to be observed rather seldom at depths over 4 km

    The intellectual information system for management of geological and technical arrangements during oil field exploitation

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    The intellectual information system for management of geological and technical arrangements during oil fields exploitation is developed. Service-oriented architecture of its software is a distinctive feature of the system. The results of the cluster analysis of real field data received by means of this system are shown

    Development of dysbiosis in the organism of rats receiving a high-fat diet

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    Background. To determine the effect on the degree of dysbiosis in the organs and tissues of rats treated with high-fat diet (HFD) using fats with various fatty acid compositions.Methods. We used ordinary (high-linoleic) sunflower oil, high-oleic sunflower oil, butter, palm and coconut oils. Rats were fed with 15 % of each of the fats for 64 days. In the blood serum from v.cava and v. porta, in the liver, heart, brain, skeletal muscles and intestinal mucosa, urease activity (an indicator of bacterial insemination), lysozyme activity (a factor of non-specific immunity) were determined, and the degree of dysbiosis was calculated from the ratio of relative urease and lysozyme activities. Results. The activity of urease in the blood of v. porta increased in rats treated with HFD, and was significantly higher than in the blood of v.cava. In most of the studied tissues, urease activity increased after HFD, with the exception of rats receiving high-oleic sunflower oil (HOSO). In contrast, lysozyme activity was reduced in most tissues, with the exception of rats treated with HOSO. The degree of dysbiosis increased after HFD with the exception of rats treated with HOSO.Conclusion. HFD increases the translocation of bacteria from the intestine. The liver partially neutralizes the microflora coming from the intestines. In blood serum from v. cava and v. porta, urease activity (an indicator of bacterial contamination), lysozyme activity (nonspecific immunity factor) were determined in the liver, heart, brain, skeletal muscle and intestinal mucosa, and the degree of dysbiosis was calculated by the ratio of the relative activities of urease and lysozyme.Results. Blood urease activity v. porta was elevated in rats treated with HFD and was significantly higher than in blood v. cava. In most of the tissues studied, urease activity increased after HFD with the exception of rats treated with high oleic sunflower oil (HOSO), the development of dysbiosis in all tissues of the body. The exception is HOSO, which does not cause the development of dysbiosis and inflammation
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