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  • Author or Editor: V. Kovalenko x
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A method is suggested for numerical determination of heat capacity as a function of temperature using the data on nonstationary experiments. This is based on the solution of the inverse problem in the overdefined formulation, with allowance for the temperature distribution inside the solid. The algorithm developed for the solution of the problem allows determination of the heat capacity both in case of a material with a known thermal conductivity, and in the case when the thermal conductivity of the material is unknown and should be determined simultaneously with the heat capacity. The suggested method of numerical solution for the coefficient-type inverse problem of nonlinear thermal conductivity may also be of use in interpretations of the data of thermal analysis.

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Abstract  

Results of development of nuclear-physical research installations and methods of ocean bottom sediments analysis using radionuclide sources of neutron, gamma and X-ray radiations are presented. Practical applications of the above developments in expeditionary conditions aboard research vessels are summarized.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: N. Shilo, E. Ippolitov, V. Ivanenko, B. Kustov, V. Zheleznov, G. Aristov, A. Shtan, I. Ivanov, V. Kovalenko, and N. Kondrat’ev

Abstract  

A facility using a californium neutron source and a method for the neutron activation analysis of gold were developed. The sensitivity of the determination is 0.1 g/t. The sources of random and systematic errors have been studied. It has been concluded that in prospection and evaluation of gold ore deposits, the traditional test tube analysis for gold may be replaced with the developed method.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: M. Krivopustov, A. Pavliouk, A. Kovalenko, I. Mariin, A. Elishev, J. Adam, A. Kovalik, Yu. Batusov, V. Kalinnikov, V. Brudanin, P. Chaloun, V. Tsoupko-Sitnikov, A. Solnyshkin, V. Stegailov, Sh. Gerbish, O. Svoboda, Z. Dubnicka, M. Kala, M. Kloc, A. Krasa, A. Kugler, M. Majerle, V. Wagner, R. Brandt, W. Westmeier, H. Robotham, K. Siemon, M. Bielewicz, S. Kilim, M. Szuta, E. Strugalska-Gola, A. Wojeciechowski, S. Hashemi-Nezhad, M. Manolopoulou, M. Fragopolou, S. Stoulos, M. Zamani-Valasiadou, S. Jokic, K. Katovsky, O. Schastny, I. Zhuk, A. Potapenko, A. Safronova, Zh. Lukashevich, V. Voronko, V. Sotnikov, V. Sidorenko, W. Ensinger, H. Severin, S. Batsev, L. Kostov, Kh. Protokhristov, Ch. Stoyanov, O. Yordanov, P. Zhivkov, A. Kumar, M. Sharma, A. Khilmanovich, B. Marcinkevich, S. Korneev, Ts. Damdinsuren, Ts. Togoo, and H. Kumawat

Abstract  

An extended U/Pb-assembly was irradiated with an extracted beam of 2.52 GeV deuterons from the Nuclotron accelerator of the Laboratory of High Energies within the JINR in Dubna, Russia. The lay-out of this experiment and first results are reported. The Pb-target (diameter 8.4 cm, length 45.6 cm) is surrounded by a natU-blanket (206.4 kg) and used for transmutation studies of hermetically sealed radioactive samples of 129I, 237Np, 238Pu and 239Pu. Estimates of transmutation rates were obtained as result of measurements of gamma-activities of the samples. Information about the spatial and energy distribution of neutrons in the volume of the lead target and the uranium blanket was obtained with sets of activation threshold detectors (Al, Y and Au) and solid state nuclear track detectors (SSNTD). An electronic 3He neutron detector was tested on-line. A comparison of experimental data with theoretical model calculations using the MCNPX program was performed yielding satisfactory results.

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