Helicopter Fuselage Drag ─ Combined Computational Fluid Dynamics and Experimental Studies

In this paper, wind tunnel experiments are combined with Computational Fluid Dynamics (CFD) aiming to analyze the aerodynamics of realistic fuselage con¦gurations. A development model of the ANSAT aircraft and an early model of the AKTAI light helicopter were employed. Both models were tested at the subsonic wind tunnel of KNRTU-KAI for a range of Reynolds numbers and pitch and yaw angles. The force balance measurements were complemented by particle image velocimetry (PIV) investigations for the cases where the experimental force measurements showed substantial unsteadiness. The CFD results were found to be in fair agreement with the test data and revealed some §ow separation at the rear of the fuselages. Once con¦dence on the CFD method was established, further modi¦cations were introduced to the ANSAT-like fuselage model to demonstrate drag reduction via small shape changes

Cosmic microspheres in the Carboniferous deposits of the Usolka section (Urals foredeep)

© 2017Magnetite microspheres from the Carboniferous deposits of the Usolka reference section were studied by probe microanalysis, with comparison of the distributions of chemical elements and microspheres. The presence of microspheres in sedimentary strata is considered to be an additional factor for stratigraphic correlation between sedimentary sections. The microspheres are shown to be of cosmic nature. The Late Paleozoic paleoclimatic changes (extreme cooling) and biotic crises were caused by the periodical Solar System motion in the Galaxy, cosmic-dust fallout, and meteorite bombardments of the Earth

Функциональная оценка левого предсердия с помощью эхокардиографии после радиочастотной абляции устьев легочных вен и левого предсердия у пациентов c хирургическим лечением фибрилляции предсердий и протезированием митрального клапана

Material and methods. A prospective, randomized, single-center study was conducted. It included 166 patients with mitral valve disease divided into three groups depending on types of AF: with paroxysmal AF at 14 (8.4%) patients, with persistent AF at 63 (37, 9%) patients and with long-term persistent AF at 89 (53.6%) patients hospitalized at the Interregional Clinic and Diagnostic Center Kazan from 2011 to 2018. An average age of patients was 57 ± 5 years old, mainly females amounted to 97 (58.4%).Results. Surgical isolation of the pulmonary vein ostia and the left atrium by RFA at mitral valve replacement significantly improves the contractile function of the left atrium, which allows us to judge about the improvement of the transport function of the left heart chambers as a whole.Цель исследования: оценка геометрического, функционального ремоделирования левого предсердия (ЛП) после радиочастотной абляции (РЧА) устьев легочных вен, ЛП у пациентов при протезировании митрального клапана.Материал и методы. Проведено проспективное рандомизированное одноцентровое исследование. В исследование включено 166 пациентов с заболеванием митрального клапана, разделенных на 3 группы в зависимости от длительности фибрилляции предсердий (ФП): с пароксизмальной ФП у 14 (8,4%) пациентов, с персистирующей ФП у 63 (37,9%) пациентов и с длительной персистирующей ФП у 89 (53,6%) пациентов, госпитализированных в Межрегиональный клинико-диагностический центр Казани с 2011 по 2018 г. Средний возраст пациентов составил 57 ± 5 лет, женщин было 97 (58,4%).Результаты. Хирургическая изоляция устьев легочных вены и ЛП с помощью РЧА при замене митрального клапана позволяет восстановить синусовый ритм, что определяет ремоделирование ЛП, таким образом отмечается улучшение транспортной функции левых отделов сердца в целом

Especially the chemical reactions of combustion of methane-hydrogen fraction in radiant furnaces

This article examines the processes that occur during chemical reactions of combustion, and the distribution in terms of radiant furnace temperature in the heating furnace feedstock and hydrogen-containing gas at facilities hydrotreating vacuum gas oil by burning methane-hydrogen fraction instead of natural gas

Cosmic microspheres in the Carboniferous deposits of the Usolka section (Urals foredeep)

© 2017Magnetite microspheres from the Carboniferous deposits of the Usolka reference section were studied by probe microanalysis, with comparison of the distributions of chemical elements and microspheres. The presence of microspheres in sedimentary strata is considered to be an additional factor for stratigraphic correlation between sedimentary sections. The microspheres are shown to be of cosmic nature. The Late Paleozoic paleoclimatic changes (extreme cooling) and biotic crises were caused by the periodical Solar System motion in the Galaxy, cosmic-dust fallout, and meteorite bombardments of the Earth

Composition and morphology of metal microparticles in paleozoic sediments of caspian depression

© Research India Publications 2015. Using the microprobe analysis 18 samples of metallic micro-particles were studied (spheres, plates, coils, wire) from Paleozoic deposits of the Caspian basin. The morphology of the microparticles and their chemical composition showed that the microparticles have different origins. The formation of spiral and wire type forms is associated with volcanic activity, and magnetite microspheres were formed in the Earth atmosphere during the flight and meteorite ablation. It is determined that Mn (0.8-2%), rarely Cr is uniformly distributed in magnetite microspheres. In the interstices of magnetite tablets the releases of native nickel, nickel oxides, the awaruite of Ni3Fe are met rarely. Among the spiral formations the intermetallic compositions of Fe-Cr-Mn and Fe-Cr-Ni are met and the mechanism of their formation in the development of subvolcanic chamber is proposed. The diagrams lg (Cr/Ni) - lg (Cr/Mn) and lg (Fe/Cr) - lg (Fe/Ni) allow to reveal the geochemical differences of metallic microparticles of volcanic and cosmic origin. The metallic microparticles discovered in sedimentary rocks, may be an additional tool for regional parallelization of multipartite cuts, may lead to the revision of biotic process models, the assessment of terrestrial and cosmic processes impact on them, help in the search for hydrocarbon deposits and stratified deposits of solid minerals

Composition and morphology of metal microparticles in paleozoic sediments of caspian depression

© Research India Publications 2015. Using the microprobe analysis 18 samples of metallic micro-particles were studied (spheres, plates, coils, wire) from Paleozoic deposits of the Caspian basin. The morphology of the microparticles and their chemical composition showed that the microparticles have different origins. The formation of spiral and wire type forms is associated with volcanic activity, and magnetite microspheres were formed in the Earth atmosphere during the flight and meteorite ablation. It is determined that Mn (0.8-2%), rarely Cr is uniformly distributed in magnetite microspheres. In the interstices of magnetite tablets the releases of native nickel, nickel oxides, the awaruite of Ni3Fe are met rarely. Among the spiral formations the intermetallic compositions of Fe-Cr-Mn and Fe-Cr-Ni are met and the mechanism of their formation in the development of subvolcanic chamber is proposed. The diagrams lg (Cr/Ni) - lg (Cr/Mn) and lg (Fe/Cr) - lg (Fe/Ni) allow to reveal the geochemical differences of metallic microparticles of volcanic and cosmic origin. The metallic microparticles discovered in sedimentary rocks, may be an additional tool for regional parallelization of multipartite cuts, may lead to the revision of biotic process models, the assessment of terrestrial and cosmic processes impact on them, help in the search for hydrocarbon deposits and stratified deposits of solid minerals

Education and ways of reducing nitrogen oxides in the boiler tg-104 with a direct-flow-vortex burners and the peripheral gas supply

This article deals with the distribution of temperature and incident heat flux on the display surface boiler heating TG-104 at work at the Urengoy gas and the thermal efficiency of the burners to reduce the formation of nitrogen oxides. The temperature of the combustion products was measured using an optical method and thermocouple contact method. The incident heat fluxes measured by the radiometer the full radiation. Burned fuel - natural gas according to GOST 30319.1-96 with the lower heat of combustion 35146 kJ/m3