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Документ Thermodynamic analysis of the possible existence of the ternary Вa₃СоAl₄O₁₀ compound in the ВаО–СоО–Аl₂O₃ system(Український державний хіміко-технологічний університет, 2020) Shabanova, G. N.; Korohodska, A. M.; Gamova, O. A.; Gaponova, H. A.; Levadnaya, S. V.The work was aimed at the thermodynamic estimation of the possible existence of ternary compound Вa₃СоAl₄O₁₀ in the BaO–CoO–Аl₂O₃ system. To this end, the composition of the expected ternary compound was calculated considering that this compound should be located in the CoAl₂O₄–Вa₃Аl₂O₆ conode. With reference to this, the temperature and the eutectic composition in the binary section of CoAl₂O₄–Вa₃Аl₂O₆ were estimated. The standard enthalpy of the formation of the above three-component compound, the standard entropy and the coefficients of the temperature dependence of the heat capacity were calculated. Using the method developed by Babushkin, the temperature dependence of the Gibbs energy for the formation of Вa₃СоAl₄O₁₀ compound was determined for the range of 800 to 2000 K. The probability of the Вa₃СоAl₄O₁₀ formation was evaluated both for its preparation both from pure aluminum, cobalt and barium oxides and from barium carbonate, aluminum and cobalt oxides. In addition, the probability of the Вa₃СоAl₄O₁₀ formation from binary compounds CoAl₂O₄ and Вa₃Аl₂O₆ was estimated. The possible formation of the ternary compound from Вa₃Аl₂O₆, BaAl₂O₄ and CoO was also considered, because the Вa₃СоAl₄O₁₀ compound is located in this triangle. The graphs of the change of Gibbs energy with temperature (800–2000 K) were plotted for all reactions. The obtained results showed that the formation of the ternary compound from barium, aluminum and cobalt oxides is more feasible from the standpoint of thermodynamics than from the binary compounds.Документ Oxidation resistance of nano-reinforced PC-refractories modified with phenol formaldehyde resin. Part 4. Thermodynamic evaluation of phase formation within Mg–O–C–Al, Mg–O–C–Ni and МgO‒Al₂O₃‒NiO‒SiO₂ systems using SiC + Al + Ni (NiO) complex antioxidant(Kluwer Academic/Plenum Publishers, USA, 2017) Semchenko, G. D.; Borisenko, O. N.; Brazhnik, D. A.; Logvinkov, S. M.; Povshuk, V. V.; Shuteeva, I. Yu.; Angolenko, L. A.; Chopenko, N. S.; Vasyuk, P. A.Results are given for the synthesis and co-existence of phases formed from components of complex organic- inorganic antioxidant formed during modification of phenol-formaldehyde resin (PFR) and graphite with silica alkoxide and inorganic or organic nickel precursors. Thermodynamic analysis is given for the Mg–Al–C and Mg–O–Ni–C systems. It is shown that the periclase and carbon can coexist with aluminum and nickel, and also that oxidized antioxidants Al₂O₃ and NiO can interact respectively with the periclase and with the synthesized SiC formed during modification of PFR with silica. In considering the NiO‒MgO‒Al₂O₃‒SiO₂ system it is established that during service noble spinel will be synthesized from the complex antioxidant components, facilitating an increase in PC-refractory durability in service.Документ Theoretical background of rock failure at hydraulic seam fracture and aftereffect analysis(Національний технічний університет "Дніпровська політехніка", 2018) Biletskyi, V. S.; Horobets, L.; Fyk, M. I.; Al-Sultan, M.Purpose. Theoretical substantiation of the methodological foundations of possible effects and aftereffects identification of the hydraulic seam fracture (HSF) technology. Methods. The research structure and procedure includes: studying the power engineering aspect of the rock failure, the acoustical wave effects; thermodynamic analysis of rock failure, analysis of surfaces mechanic activation at rock failure and aftereffect of the primary pore space self-development at the HSF due to the Rebinder’s effect. Findings. It was established that among the fundamental consistent patterns that determine the formation and development of the HSF technology aftereffects during formations mining, are the methodological provisions and criteria for failure parameters prediction and grinding effects, namely: the average and local energy density of geoenvironment destruction, efficiency of grinding, the average particle and pore size, the specific surface area, the specific energy consumption per unit of the resulting surface. The connection between the parameters of the acoustic wave and the size of the fractures, which forms the basis of the acoustic emission (AE) method, is experimentally confirmed. Originality. It is established that the database for evaluating the expected fracture effects in the working zone of the HSF is: AE activity, specific acoustic radiation, spectrum of signals, characteristic amplitudes under the condition of physical modeling on the model samples of the geoenvironment behavior. It is shown that the critical state of a substance corresponding to the beginning of failure at the microlevel should be considered from the standpoint of thermodynamics as a phase change (evaporation, sublimation) near the critical point, based on the temperature critical values and the specific energy of the phase change. The presence of surfaces mechanic activation in the rock failure is experimentally proved. The hypothesis concerning the rock pore space development aftereffect during hydraulic seam fracture due to the Rebinder’s effect is presented. Practical implications. It is proposed to size up the degree of geoenvironment destruction in the process of the HSF by the Kd parameter, which is equal to the product of the maximum amplitude of acoustic signals on the total acoustic activity of the destruction zone. It is established that the conditions for rock failure at the HSF are determined by the relationship between the rock pressure P and the volume energy density W of the failure. It is shown that the level of surfaces mechanoactivation can be estimated by adsorption characteristics – the adsorption potential and the pH of the newly discovered surfaces.Документ Строение системы MgO – Al₂O₃ –TiO₂ – SiO₂ и ее значение для производства термически и химически стойкой керамики(Украинский государственный химико-технологический университет, 2015) Рыщенко, Михаил Иванович; Питак, Ярослав Николаевич; Федоренко, Елена Юрьевна; Лисюткина, Мария Юрьевна; Бурик, О. А.Документ Оценка процедуры ретрофита хладагента в холодильных машинах и тепловых насосах на основе термодинамического анализа(Казанский национальный исследовательский технологический университет, 2013) Шерстюк, А. В.; Братута, Эдуард Георгиевич; Харлампиди, Дионис ХарлампиевичПроведено расчетное исследование энергетической и эксергетической эффективности холодильных машин и теплонасосных установок в широком диапазоне изменения режимных параметров и видов рабочих тел, с целью выбора сервисных хладагентов для замены в действующих установках.