Synthesis of Nanoparticles of Fe-Co-Ni Three-component Alloy Capsulated Into Carbon Matrix of Fe-Co-Ni/C Nanocomposites

Nanoparticles of Fe-Co-Ni three-component alloy capsulated into carbon matrix were synthesized. Structure, phase composition and magnetic properties of obtained materials were defined by diffractometry and magnetometry. It was established that composition of nanoparticles is determine by synthesis temperature, because nanoparticles of three-component alloy are forms by dissolution of cobalt in Fe-Ni alloy. Magnetization of Fe-Co-Ni/C nanocomposites and coercive force increases from 26 up to 58 A·m2/kg during temperature increase that relates with growth of particles size and increase of cobalt content in the alloy

Basic Principles of Betavoltaic Elements and Prospects of their Development

The basic technical principles and means of increase in betavoltaitic elements effectiveness have been analyzed by comparing with their closest analogue – photoelectric semiconductor converters. The geometric parameters of radiation sources for these elements and their capacities have been estimated. It is shown the radiation source 63Ni foil thickness should not exceed a few micrometers, and maximum energy conversion efficiency can achieve ~ 16 %

Synthesis of Nanoparticles of Fe-Co-Ni Three-component Alloy Capsulated Into Carbon Matrix of Fe-Co-Ni/C Nanocomposites

Nanoparticles of Fe-Co-Ni three-component alloy capsulated into carbon matrix were synthesized. Structure, phase composition and magnetic properties of obtained materials were defined by diffractometry and magnetometry. It was established that composition of nanoparticles is determine by synthesis temperature, because nanoparticles of three-component alloy are forms by dissolution of cobalt in Fe-Ni alloy. Magnetization of Fe-Co-Ni/C nanocomposites and coercive force increases from 26 up to 58 A·m2/kg during temperature increase that relates with growth of particles size and increase of cobalt content in the alloy

Theoretical Studies of the Structure of the Metal-carbon Composites on the Base of Acryle-nitrile Nanopolimer

The presence of the metal compounds in the acryle-nitrile nanopolimer (PPAN) leads to the formation of the metal nanoparticles. The metal-carbon nanocomposites based on PPAN including pair connections with iron and cobalt has been theoretically investigated. The spatial configuration of the nanocomposite for each option of the arrangement of metal atoms has been received. The analysis of the received results for all options of the arrangement of the metal atoms allowed defining the binding energy of the systems and the width of the forbidden gap ΔЕg of the nanocomposite. The analysis of the electronic and energy struc-tures of the system found out that the introduction of the metal atoms leaded to the essential reduction of the width of the forbidden zone of the composite in comparison with the pure PPAN. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3628

Features of Formation of the Nanoparticles of Alloys in Metal-carbon Nanocomposites FeCo / C and NiCo / C on Based Polyacrylonitrile

By the method of IR-heating the precursor on base of polyacrylonitrile, compounds of iron, cobalt and nickel metal-carbon nanocomposites were obtained, representing an ensemble of nanoparticles of intermetallic FeCo (NiCo), dispersed in nanocrystalline carbon matrix. XRD analysis revealed that the carbon structure of the PAN-based matrix changed from amorphous to nanocrystalline at the processing temperatures in the range 200-700 °C. Thus there is a reduction of metals from compounds released by degradation of the polymer with hydro-gen. FeCo alloy nanoparticles formed at synthesis temperatures T≥500 °C, in the case of nanocomposites Ni-Co / C alloy nanoparticle formation is possible at T ≥ 270 °C, which is associated with a lower temperature com-pared to the recovery of nickel from iron. According to the results of TGA and DSC found that metals are capable of initiating the chemical transformation in the PAN, resulting in reduction start temperature degradation. Ac-cording to the results of DSC revealed that the formation of nanoparticles is accompanied by release of heat due to exothermic processes occurring in the nanocomposites. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3631

The Current-voltage Characteristics Simulation of the Betavoltaic Power Supply

In order to optimize betavoltaic power supply it was calculated the current-voltage characteristics when changing the depth of the upper p-layer and at changing doping levels structure areas. It is shown that an increase in the depth reduces the short-circuit current and thus reduces the open circuit voltage. It has been observed that the concentration of the lightly doped region more significantly influence on the current-voltage characteristics than the depth of the p-n-junction. The concentration of the n-region, equal to 1014 cm – 3, can be considered as during betavoltaic power supply design. It is shown that, by increasing the power supply activity the conversion efficiency of the structure increases, too

Optimization of Energy Conversion Efficiency Betavoltaic Element Based on Silicon

It was developed the technology of manufacturing planar betavoltaic converter based on silicon, providing a higher rate of conversion of ionizing radiation into electrical energy by reducing reverse currents. The active region of silicon p-i-n structure is 1 cm2, which is irradiated by the of radionuclide 63Ni with the activity 2,7 mCi/cm2. The results of experimental studies of C-V samples are presented. The values of the open-circuit voltage (Voc) 0.111 V are presented and short circuit current density (Jsc) 27 nA/cm2. The maximum density of output power (Pmax) was 1.52 nW/cm2

Influence of the Ratio of Metal Composed Nanocomposites Fe-Co / C on Phase Composition

Metalcarbon nanocomposites based on polyacrylonitrile and nickel chloride are synthesized under the influence of infrared heat. The resulting materials represent a system of carbon matrix formed during the carbonization of PAN, and distributed in it nickel nanoparticles. The average size of the nanoparticles in the nanocomposite was 15-25 nm. It was found that the distribution of nickel nanoparticles sizes is determined by temperature synthesis nanocomposite. Thus with increasing temperature, the predominant average particle size of the metal increases, and the distribution is spread and shifted toward larger sizes. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3360

Современные аспекты применения заместительной гормональной терапии при коррекции нарушений со стороны сердечно-сосудистой системы у женщин с климактерическим синдромом

Hormone replacement therapy (HRT) has been widely used for reliving climacteric disorders. The purpose of present study is to evaluate myocardium function in case of HRT application. Application of hormone replacement therapy has enhanced microcirculation and myocardium metabolism if cardiac embarrassment was induced by pathology in endocrine and central nervous system.В работе изучено состояние миокарда у больных с климактерическим синдромом и произведена оценка влияния ЗГТ на имеющиеся нарушения. Показано, что изменения со стороны ССС при КС, нормализация которых происходит в процессе применения ЗГТ, носят метаболический характер и обусловлены патологическими процессами в эндокринной и ЦНС, наблюдаемыми при данном заболевании