Preview
Vol 2, No 2 (2018)
98-103 403
Abstract

The paper presents the dependence of the degradation degree in various aggressive media and time in a medium. The greatest deterioration in crystallographic characteristics of nanostructures in corrosive media is observed on the day 10th , which is due to partial destruction of the crystal structure as a result of oxidation processes. Also, an increase in the oxygen concentration in the structure leads to an increase in disorder regions, amorphization, and subsequent destruction of samples.

104-109 450
Abstract

The current research is focused on development of electroforming method for coating of porous membranes by graphene oxide. A mixture based on polymethylmetacrylate dissolved in acetone and graphene oxide was pumped through the syringe pump onto the needle and high voltage was applied to both electrodes, one of which was on a glass plate, and the second was a needle thereby forming fibers, which coated the surface of membrane uniformly. The main parameters and concentrations of used polymer for uniform and complete coating of the surface of membrane are studied. Surface morphology of coated membranes was studied by SEM.

110-118 372
Abstract

The technique of introduction a fluorescent dye Tris(bipyridine)ruthenium (II) chloride into nanoparticles of silicon dioxide in isopropyl alcohol was tested. The preparation of nanoparticles was carried out by means of the Stober method. The optimal reaction conditions were determined. It was found out that the penetration of a dye into silicon dioxide nanoparticles reduced the effect of concentration quenching of the dye and made it possible to achieve an increase in fluorescence intensity in the solution more than twofold. An attempt was made to functionalize the obtained particles by introducing amino groups onto the particle surface. Fused silver nanoparticles were seeded with silver nanoparticles.

119-128 373
Abstract

In present work we study the effect of the Omega ( ω(782) ) resonance on the response functions for the incoherent positive pion electroproduction forms the deuteron at different values for the four-momentum transfers squared (Q2 ) and the virtual photon lab energy ( klab0 ). The study is carried out in the impulse approximation (IA) i.e. the final state interactions are neglected. The elementary amplitude for pion electroproduction is taken from the MAID-2007 model. The effect seems to be very small but almost increase with increasing the virtual photon lab energy.

129-139 446
Abstract

The production of neutrons can be carried out with the bombardment of the nuclei of heavy atoms, with accelerated and energetic particles (generally electrons). The electron collides with the target nuclei, so, 20 to 30 neutrons are produced by a process called "spallation". Several countries begin to develop neutron sources especially in the United States, Europe and Japan. The development of new measuring instruments and methods has generally increased the demand for neutron utilization in several areas, such as accelerator proton-based, where protons bombard a heavy metal target. The atoms of the target are excited, resulting in neutron emission.

140-150 421
Abstract

The article presents the results of experimental studies of a double-chamber linear circuit DC electric arc plasmatron in experimental and industrial conditions. The electric arc plasmatron of the VORTEX-200 linear circuit with a rated power of 200 kW is designed for plasma ignition of a pulverized-coal torch, its stabilization and oil-free ignition of pulverized-coal boilers of thermal power plants.The linear circuit plasmatron contains two water-cooled casings isolated from each other, one of which has a hollow cylindrical electrode - a cathode having swirlers of the plasma-forming gas at both ends, and the other has an output electrode - an anode-diffuser having a channel with a cylindrical segment at one end and the exit nozzle in the form of a diffuser at the other end.The power of the plasmatron, depending on the process parameters, can vary from 80 to 230 kW. The plasmatron has a stable powerful air plasma torch. Tests of such plasmatrons showed their high reliability and possibility of their operation in difficult conditions of thermal power plants (high level of dust and humidity, high temperatures near the boilers). Measured volt-ampere characteristics of the plasmatron enabled us to determine the region of stable arc combustion from 350 to 475 A. Parameters of the plasmatron operation at its nominal power of 200 kW and the flow rate of the plasma-forming gas of 1000 l/min are attained at currents not exceeding 450 A. The use of mechanical ignition of the plasmatron with a needle from a refractory material, instead of breakdown the inter electrode gap by an oscillator, increased the reliability of its operation.The device for axial scanning of binding of the cathode spot of the arc, which allows us to increase the surface of cathode erosion many times,was developed. The use of azimuthal and axial scanning of the cathode spot of the arc of the plasma torch makes it possible to increase the service life of the cathode up to 200 hours with a service life of the massive anode exceeding 500 hours.

151-158 390
Abstract

Current paper describes the experimental dual-purpose application of microwaves in a controlled clinical trial on optimizing therapy for chronic neurological disorders. As a part of integrated treatment, low-intensity microwave-assisted blood modification has been used. It represents a physiotherapeutic method based on the autologous blood transfusion (self-blood treatment) after the short-term exposure to microwaves ( lambda = 7.2 mm). Because of beneficial clinical impact of the microwave autohemotherapy previously observed, we aimed to find a possible way to track a manifestation of nonthermal microwave effects. For this purpose, we have applied a microwave single-frequency ( lambda = 7.6 mm) dielectrometry technique as a tool for blood sensing. Also, we used the osmotic fragility test to detect the membrane-receptor activity level using patients’ red blood cells before and after the course of therapy. Our preliminary results have shown an enhancement of blood cell reactivity and a clearly defined tendency to normalizing parameters under study in those patients who received the integrated treatment. By analyzing the data obtained by different methods, we have revealed that characteristics are well correlated.

159-164 386
Abstract

Plasma disruption in the thermonuclear facility leads to a release of large energy flows to the chamber wall. The pulse duration is 10-6 -10-4 s, energy fluxes are of the order of 108 - 1011 Wm-2 . High temperature of the protective coating surface causes its evaporation and, probably, destruction under the action of thermal stresses. A promising material for the first wall protection is, in particular, molybdenum. In order to check suitability of molybdenum as a protective coating, an experiment on irradiation of a molybdenum sample with electrons (parallelepiped - 2x10x0.3 mm) was carried out. The energy flux was J =4x1011 W m-2 ; pulse duration t = 2 micros . The weight loss of the sample was 2.1 mg; cracking of the trained surface was observed. The purpose of this analysis is to calculate the temperature fields to estimate the mass of evaporated molybdenum and to determine critical thermal stresses.

165-170 388
Abstract

The work represents the results of experimental research of aerodynamics of three dimensional turbulent jets flowing from nozzles with rectangle outflow face. The results of measurements of average and pulse flow characteristics of threedimensional jets are given. The data on axis speed and turbulence intensity are given and an attempt to reveal their interrelation is made. The results of experimental data comparison on axis speed attenuation of three dimensional jets with the data for axis symmetric stream are presented.



ISSN 2522-9869 (Print)
ISSN 2616-8537 (Online)