Almaty, Kazakhstan
Almaty, Kazakhstan

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Dergacheva M.B.,D.V. Sokolsky Institute of Organic Catalysis and Electrochemistry | Mit K.A.,Physicotechnical Institute | Urazov K.A.,Kazakh-British Technical University | Gremenok V.F.,National Academy of Sciences of Belarus
Journal of Surface Investigation | Year: 2013

The results obtained by investigating the surface morphology and optical properties of thin CdS films formed on transparent glass and glass/indium-tin oxide (ITO) substrates via the chemical and electro-chemical methods are presented. Thin cadmium sulfide films are employed as optical windows in thin-film polycrystalline solar cells. Closely packed cadmium sulfide nanoparticles are observed on the conducting oxide (ITO) surface by means of atomic-force microscopy. Large particles (150-300 nm) comprise smaller particles with sizes of 20-30 nm. Thin CdS layers are characterized by a relatively high level of transmission (∼60%) in the long-wavelength spectral region (520-600 nm). © 2013 Pleiades Publishing, Ltd.

Dmitrieva E.A.,Physicotechnical Institute | Mukhamedshina D.M.,Physicotechnical Institute | Beisenkhanov N.B.,Kazakhstani British Technical University | Mit' K.A.,Physicotechnical Institute
Glass Physics and Chemistry | Year: 2014

Undoped films and films with the addition of NH4F and NH 4OH have been prepared by layer precipitation of solutions on glass substrates by sol-gel technology with the use of centrifugation. It has been shown via X-ray diffraction that all films under study are composed of SnO 2 nanocrystals. Measurements of surface resistance confirmed the presence of fluorine atoms in the films that were prepared from the solutions with NH4F. Scanning electron microscopy has demonstrated the formation of a dendrite structure and an increase in film porosity with the addition of NH4F and NH4OH to the film-forming solution. Addition of NH4F and NH4OH to the solution has resulted in the increase of the gas sensitivity of the films; however, it has been accompanied by a decrease in film transparency and the disappearance of interference peaks in the transmittance spectra. © 2014 Pleiades Publishing, Ltd.

Ryabikin Yu.A.,Physicotechnical Institute | Kairbekov Zh.K.,Al Farabi State University of Kazakhstan | Zashkvara O.V.,Physicotechnical Institute | Eshova Zh.T.,Al Farabi State University of Kazakhstan
Solid Fuel Chemistry | Year: 2011

Results of a study of the paramagnetic characteristics of brown coal from the Kiyaktinskoe deposit (Kazakhstan) in a native state and after mechanical treatment and electron irradiation are reported. The effects of these actions on changes in the paramagnetic properties of the test coal and on the intensification of a coal hydrogenation process are discussed. It was found that the concentration of free radicals changed only slightly after mechanical treatment in a ball mill at room temperature in an atmosphere of air, whereas the concentration of Fe3+ ions noticeably increased. Upon the electron irradiation of coal, the dose depen- dence of the concentration of free radicals passed through a maximum at a dose of 100 kGy. At the same radi- ation dose, the yield of a kerosene-gas oil fraction upon the hydrogenation of Kiyaktinskoe coal increased, and the total yield of liquid products increased upon the irradiation of coal and a catalyst (bauxite 094) to a dose of 100 kGy. It was hypothesized that Fe3+ ions, which were additionally formed upon coal grinding and irradiation, can serve as an internal catalyst in the course of coal hydrogenation. © 2011 Allerton Press, Inc.

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