184 research outputs found

    Open Hemispherical Imaging Dielectric Resonator with Whispering Gallery Modes

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    The imaging dielectric resonators with whispering gallery modes (WGMs) for the creation of a new class of millimeter wave solid-state oscillators, devices for the investigation of high temperature superconductors, were suggested. They contain a dielectric element as a semidisk or a cylinder or a hemisphere and a flat metal mirror. The latter is a necessary element for placing in the resonator field active elements or conductor samples of materials. There is an important question about the dependence of the resonant frequencies and Q-factor of these resonators on impedance of the resonator mirror. In the present paper new investigation results of the open hemispherical imaging dielectric resonator (HIDR) with WGMs are represented

    Paramagnetic Meissner effect in ZrB12 single crystal with non-monotonic vortex-vortex interactions

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    The magnetic response related to paramagnetic Meissner effect (PME) is studied in a high quality single crystal ZrB12 with non-monotonic vortex-vortex interactions. We observe the expulsion and penetration of magnetic flux in the form of vortex clusters with increasing temperature. A vortex phase diagram is constructed which shows that the PME can be explained by considering the interplay among the flux compression, the different temperature dependencies of the vortex-vortex and the vortex-pin interactions, and thermal fluctuations. Such a scenario is in good agreement with the results of the magnetic relaxation measurements.Comment: accepted by New Journal of Physic

    Whispering-Gallery Modes in Shielded Hemispherical Dielectric Resonators

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    The results of the numerical and experimental investigations of whispering-gallery (WG) modes in shielded hemispherical dielectric resonators are presented in this paper. It is shown that the Q factor of WG modes in the shielded resonator can be ten times much higher than the Q factor of the similar open hemispherical dielectric-resonator modes. Shielding the resonator can decrease the dimensions of both the dielectric hemisphere and resonator as a whole, saving the high-Q factor of WG modes. The usage of a cylindrical shield and local flat reflectors in the experiment provides the investigation of the high-Q factor of WG modes in the resonator

    About Resonant Modes at the Shielded Dielectric Hemisphere

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    The resonant modes, which are excited at the shielded dielectric hemisphere, are investigated by the theoretical and experimental methods. The low-Q-factor modes of air cavity and high-Q-factor whispering gallery modes of dielectric structure are existed together in the case of high radial index value. The Q-factor value of the whispering gallery modes of the shielded dielectric sphere with the certain correlation between the sizes of dielectric hemisphere and metal shield can be more great than the Q-factor of the whispering gallery modes of the similar open dielectric resonator

    Technology development of obtaining essential fatty acids from hydrobionts hydrolyzates

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    Articleɷ-3, 6-fatty acids from hydrobiontsare a minor component in the nutrition of European countries population. This causes a number of diseases, such as cardiovascular ones, cancer etc. There is a task of concentrating these acids in oil due to the fact that to meet their daily needs it is problematic to use large quantities of fish oil-from 15 to 20 g. Particularly rich in ɷ-3, 6-acids are wastes from the cutting of hydrobionts, containing muscle tissue and skin. Protein hydrolysates were obtained from rainbow trout (Oncorhynchusmykiss) and Atlantic herring (Clupeaharengus) wastes by the electrochemical method using electrolyzers of the original design which are allowed to be used in food industry. A technological scheme of separating of lipids from protein hydrolyzates has been developed and experimental batches of oil samples have been developed. To concentrate the fatty acids the cryoconcentration method was used. The phase transitions of the obtained lipids were studied after their cryoconcentration in the temperature range from + 15 °C to minus 40 °C in the environment of calcium chloride using a low-temperature refrigeration unit. To analyze phase transitions the plant was used, which is a container with a solution of calcium chloride cooled by a low-temperature refrigeration machine. The properties of 5 fractions of lipids formed at the time of lipid phase transitions have been identified and studied (the fractional composition, acid, iodine numbers, the content of polyunsaturated fatty acids (PUFAs), vitamin D3 and A). It was established that as cryoconcentration increases the concentration of PUFAs, reaching values close to 90%, which allows the resulting product to be attributed to biologically active food additives (BAA). By calculation, it was shown that to create functional food products on fish base from fish of the Gadidae family it is enough to inject 4 grams of BAA to 100 grams of the product. Organoleptic properties of food products from low-fat fish species were improved
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