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It has been shown that the modified sol-gel method (method Pechini) successfully synthesizes multielement oxides based on bismuth niobate, crystallizing in the pyrochlore structure type (space group Fd-3m). The synthesis temperature of a single-phase sample is 950 ?С, which is one hundred degrees lower than the calcination temperature in the traditional ceramic synthesis method. The average crystallite size, determined by X-ray diffraction, varies from 39 (850 ?С) to 48 nm (1050 ?С) depending on the sintering temperature. According to X-ray phase analysis, the unit cell parameter is 10.4872(6) ?. The results of elemental mapping indicate a uniform distribution of metal atoms on the surface of the sample, and X-ray energy dispersive analysis showed that the chemical composition of the synthesized sample corresponded to the specified theoretical composition.
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The possibility of increasing the current density of a beam of charged particles (“focusing”) using tapered glass channels without involving external energy sources is currently being actively implemented for positively charged ions. In relation to electron beams, this possibility is not used due to the lack of experimental data on the process of grazing interaction of electron beams with a dielectric surface. It is necessary to study the degree of compression of the electron beam by tapering capillaries depending on their geometric parameters, as well as to study the time characteristics of the focusing process. In this work, an experimental study of the degree of compression of an electron beam with an energy of 10 keV was carried out using a glass tapering channel 15 mm long with an input/output internal diameter ratio of 1.15 mm/0.3 mm. An increase in the beam current density at the output for a capillary with the above parameters was demonstrated up to 2.7 times for a position where the channel axis is parallel to the axis of the original beam. Moreover, this increase in density is estimated for electrons that have lost no more than 1 keV of their initial energy. The stability of the process of electron transmission by a tapering capillary is also shown, regardless of the orientation of the capillary relative to the direction of the original beam.
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This study is devoted to the study in diagnostics of macro-micro cracks in pipes coated with silicate-enamel, which is a key problem for the structural integrity of piping systems. Silicate-enamel coatings are commonly used to improve corrosion resistance, but the identification of subsurface macro-micro cracks remains challenging. Despite the fact that the process
of diagnosing macro cracks on the surface of the coating is currently underway, the issue of diagnosing macro-micro cracks is still problematic. The article emphasizes the importance of timely detection in order to prevent possible leaks and design failures, emphasizes the consequences for economic development and security. An algorithm for diagnosing microcracks on the surface of pipes with silicate-enamel coating has been developed. The test voltage of the improved electric spark flaw detector was increased to 40 kV, and microcracks of up to 1.5 mm were detected. A method of remote detection of oil leaks from oil trunk pipelines is described. As a result of the diagnostics, the coordinates and geometric parameters
of the cracks are determined.
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Compliance of buildings with fire safety requirements is an important issue for designers and builders. Based on the analysis of statistical data, conclusions are substantiated about the insufficiency of measures to ensure the fire safety of people and the role of glazing in solving this problem. The article examines a topic of mandatory fire safety requirements for glass in building. The analysis of regulatory documentation has been carried out in connection with the recent updating of basic regulatory documents on fire safety requirements. A brief overview of fire-proof glazing and fire-resistant glasses is given. Recommendations are given on the use of fire- proof glazing to increase the safety of people in case of fire.
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Bismuth germanate glasses modified with sodium oxide have been synthesized. The influence of a modifier on the spectral-luminescent properties of bismuth germanate glasses has been studied. The ratios of Bi2O3 and Na2O concentrations
at which IR luminescence of these glasses is possible were found.
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Bismuth-containing chromates BixCrO1.5x+3 with a variable molar ratio of 1 ? n(Bi)/n(Cr) ? 38 were synthesized using
a ceramic method from Bi (III) and Cr (III) oxides. Depending on the n(Bi)/n(Cr) ratio, the calcined samples acquire a color from green to dark red. Ceramics turn red when subjected to high-temperature treatment in air (at 650 ?С) of a mixture
of oxides with a significant predominance of bismuth oxide n(Bi2O3)/n(Cr2O3) ? 3. It is noteworthy that calcination
of chromium (III) oxide under similar conditions does not lead to the oxidation of chromium ions. X-ray phase analysis confirmed the formation of chromates Bi6Cr2O15, Bi10Cr2O21, Bi31Сr5O61.5, Bi14CrO24. Studies of samples using X-ray
spectroscopy showed that the NEXAFS Cr2p spectra of red bismuth-chromium ceramics coincide in the main details
of the spectrum with the K2CrO4 spectrum and indicate the chromium content in the oxide ceramics in the form
of tetrahedral CrO42– ions. According to scanning microscopy data, the samples are characterized by a dense, low-porosity microstructure.
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For the first time, optical ceramics based on LuAG were obtained, simultaneously doped with Yb3+ and Er3+ ions. The optical, spectral-luminescent and kinetic characteristics of ceramics Y2,82Yb0,15Er0,03Al5O12 (YAG 5-Yb, 1-Er) and Lu2,82Yb0,15Er0,03Al5O12 (LuAG 5-Yb, 1-Er) have been studied. It is shown that when luminescence is excited
at a wavelength of 940 nm in YAG 5-Yb, 1-Er and LuAG 5-Yb, 1-Er ceramics, the energy of exciting radiation
is efficiently transferred from Yb3+ ions to Er3+ ions.
The energy transitions that play a major role in the processes of Stokes and anti-Stokes luminescence of ceramics
YAG 5-Yb, 1-Er and LuAG 5-Yb are determined, and a diagram of these transitions is shown. A mutual change in
the intensity of anti-Stokes luminescent bands caused by the transitions 2H11/2 ? 4I15/2 (525 nm) and 4S3/2 ? 4I15/2 (546 nm) depending on the power of the exciting radiation was found. The possibility of using YAG 5-Yb, 1-Er and LuAG 5-Yb,
1-Er ceramics as a material for optical thermometry is demonstrated.
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The essence of the method of horizontal drilling using hydraulic fracturing is described. The influence of drill wastes and coal combustion waste on the environment is shown. A number of physical and chemical methods were carried out to study drill wastes from the Vostochno-Chumakovskoye oil field and boiler slag from the OGK-2-Novocherkasskaya SDPP.
The possibility of using boiler slag in the synthesis of aluminosilicate proppants has been studied.
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The paper presents the results of research on the influence of humidity, heat treatment temperature, fractional composition of periclase, time of aging before heat treatment, the amount of carbon in the charge on the formation of microstructure
of strength properties of periclase-carbonaceous samples. It was established that moistening of periclase-carbonaceous samples before heat treatment and time of their period of exposure in a humid atmosphere do not affect the mechanical strength. Mechanical strength of the samples increases with the increase in the composition of the charge of smaller
fractions. Change in the amount of carbon in the range from 3 to 11 % has no significant effect on the mechanical strength of the samples, so the content of carbon (graphite) in the charge mass should be determined by the individual purpose
of periclase-carbon products. In the investigated temperature range (125…250 ?С) the greatest mechanical strength
of samples corresponded to the temperature of heat treatment 200 ?С.
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The ability of isovalent substitution of zinc and cobalt atoms in the structure of willemite Zn2SiO4 was studied, ceramic pigments with willemite structure of blue, violet and blue colors were synthesized. Samples of blue color were used in the manufacture of glazes. Synthetic silicon oxide was replaced by natural quartz sand in synthesizing the pigments.
The pigments were synthesized by solid-phase reactions at a temperature of 1270 ?C. The physical and chemical properties of the synthesized blue pigment used in the composition of traditional glazes for coloring ceramic products were determined. It is established that the synthesized blue pigment has high aesthetic and decorative characteristics at a relatively low cost price.