468 research outputs found

    Synthesis and characterisation of nanocrystalline ZrN PVD coatings on AISI 430 stainless steel

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    The nanocrystalline films of zirconium nitride have been synthesized using ion-plasma vacuum-arc deposition technique in combination with high-frequency discharge (RF) on AISI 430 stainless steel at 150oC. Structure examinations X-ray fluorescent analysis (XRF), X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) with microanalysis (EDS), and transmission electron microscopy (TEM), nanoidentation method – were performed to study phase and chemical composition, surface morphology, microstructure and nanohardness of coatings. The developed technology provided low-temperature coatings synthesis, minimized discharge breakdown decreasing formation of macroparticles (MPs) and allowed to deposit ZrN coatings with hardness variation 26.6…31.5 GPa. It was revealed that ZrN single-phase coatings of cubic modification with finecrystalline grains of 20 nm in size were formed

    Psychological possibilities and functions of modern information technologies as the means for students’ self-realization in university training

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    The objective of this study was to define the leading functions of information and communication technologies that stimulate the manifestation of various forms of students’ self-realization in the educational process of the university. The socio-cultural approach that enables to reveal the role of information technologies as means for transferring the experience of culture and realizing students’ essential forces is the leading approach to study this issu

    Anti-corrosion ceramic coatings on the surface of Nd-Fe-B repelling magnets

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    The results of vacuum-arc deposition of thin ZrO₂coatings to protect the surface of Nd-Fe-B permanent magnets used as repelling devices in orthodontics are presented. The structure, phase composition and mechanical properties of zirconium dioxide films have been investigated by means of SEM, XRD, EDX, XRF and nanoindentation method. It was revealed the formation of polycrystalline ZrO₂ films of monoclinic modification with average grain size 25 nm. The influence of the ZrO₂ coating in terms of its barrier properties for corrosion in quasi-physiological 0.9 NaCl solution has been studied. Electrochemical measurements indicated good barrier properties of the coating on specimens in the physiological solution environment

    DEVELOPMENT OF THE CHP-THERMAL SCHEMES IN CONTEXTS OF THE CONSOLIDATED ENERGY SYSTEM OF BELARUS

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    The paper deals with the structural specifics of the Belarus Consolidated Energy System capacities in view of their ongoing transfer to the combined-cycle technology, building the nuclear power plant and necessity for the generating capacity regulation in compliance with the load diagram. With the country’s economic complex energy utilization pattern being preserved, the generating capacities are subject to restructuring and the CHP characteristics undergo enhancement inter alia a well-known increase of the specific electricity production based on the heat consumption. Because of this the steam-turbine condensation units which are the traditional capacity regulators for the energy systems with heat power plants dominance are being pushed out of operation. In consequence of this complex of changes the issue of load diagram provision gains momentum which in evidence is relevant to the Consolidated Energy System of Belarus. One of the ways to alleviate acuteness of the problem could be the specific electric energy production cut on the CHP heat consumption with preserving the heat loads and without their handover to the heat generating capacities of direct combustion i.e. without fuel over-burning. The solution lies in integrating the absorption bromous-lithium heat pump units into the CHP thermal scheme. Through their agency low-temperature heat streams of the generator cooling, the lubrication and condensation heat-extraction of steam minimal passing to the condenser systems are utilized. As a case study the authors choose one of the CHPs in the conditions of which the corresponding employment of the said pumps leads to diminution of the fuel-equivalent specific flow-rate by 20−25 g for 1 kW⋅h production and conjoined electric energy generation capacity lowering. The latter will be handed over to other generating capacities, and the choice of them affects economic expediency of the absorption bromous-lithium heat pump-units installation decision

    Investigation of the quasifission process by theoretical analysis of experimental data of fissionlike reaction products

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    The fusion excitation function is the important quantity in planning experiments for the synthesis of superheavy elements. Its values seem to be determined by the experimental study of the hindrance to complete fusion by the observation of mass, angular and energy distributions of the fissionlike fragments. There is ambiguity in establishment of the reaction mechanism leading to the observed binary fissionlike fragments. The fissionlike fragments can be produced in the quasifission, fast fission, and fusion-fission processes which have overlapping in the mass (angular, kinetic energy) distributions of fragments. The branching ratio between quasifission and complete fusion strongly depends on the characteristics of the entrance channel. In this paper we consider a wide set of reactions (with different mass asymmetry and mass symmetry parameters) with the aim to explain the role played by many quantities on the reaction mechanisms. We also present the results of study of the 48^{48}Ca+249^{249}Bk reaction used to synthesize superheavy nuclei with Z = 117 by the determination of the evaporation residue cross sections and the effective fission barriers of excited nuclei formed along the de-excitation cascade of the compound nucleus.Comment: 21 pages, 15 figures, 2 table

    Методы и средства повышения точности первичных измерительных преобразователей систем экологического мониторинга водной среды

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    Розглянуто методи та засоби підвищення точності первинних вимірювальних перетворювачів інтегральних, селективних та гідрофізичних параметрів систем екологічного моніторингу водного середовища.Methods and means of increase of accuracy of primary measuring converters of integrated, selective and hydrophysical parameters of systems of ecological monitoring of the water environment are considered.Рассмотрены методы и средства повышения точности первичных измерительных преобразователей интегральных, селективных и гидрофизических параметров систем экологического мониторинга водной среды

    Use of electrochemically activated aqueous solutions in the manufacture of fur materials

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    The influence of characteristics of electrochemically activated aqueous processing mediums in the treatment of fur skins with different contents of fatty substances was investigated. The use of electroactive water, namely anolytes and catholytes, forgoingantiseptics or surface-active materials (SAMs), helped to restore the hydration of fur skins and to remove from them soluble proteins, carbohydrates and fatty substances. The activating effect of anolyte and catholyte in solutions of water on the processes of treating raw furs is explained by their special physical and chemical properties, namely the presence of free radicals, ions and molecules of water which easily penetrate cells’ membranes and into the structure of non-collagen components and microfiber structure of dermic collagen. The stage of lengthy acid and salt treatment is excluded from the technical treatment as a result of using electroactivated water with high oxidizing power. A low-cost technology of processing different kinds of fur with the use of electroactivated water provides for substantial economy of water and chemical reagents, a two- to threefold accelerationof the soaking and tanning processes and creation of highly elastic fur materials with a specified set of physical and chemical properties. At the same time the technology of preparatory processes of fur treatment excludes the use of such toxic antiseptics as formalin and sodium silicofluoride, which gives grounds to regard it as ecologically safe

    АНАЛІЗ ПРИЧИН ВИНИКНЕННЯ ТА ЙМОВІРНОГО СЦЕНАРІЮ РОЗВИТКУ АВАРІЙ ПРИ РОЗВАНТАЖЕННІ НАФТОПРОДУКТІВ НА АВТОЗАПРАВНИХ СТАНЦІЯХ

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    The greatest potential danger to the technological scheme of a gas station (gas station) is a violation of the tightness tanker with oil products in the territory of a gas station. This can lead to an explosion of fuel vapor over the strait and the fire of the strait, as well as an explosion and fire inside the tanker truck. In these cases, the area of effect the damaging factors of the accident can be spread even outside the territory of the gas station. The main causes of emergencies at gas stations are: failure of the control and emergency protection equipment; excess of technological parameters of processes above critical values; violation of technological regimes; mechanical and corrosive wear of equipment; errors of repair and maintenance personnel; actions of external factors.The purpose of this work is to analyze the causes and the likely scenario for the development of accidents during the unloading of petroleum products at gas stations and develop recommendations for the prevention of these dangerous situations.A detailed analysis of the conditions for the occurrence and development of an accident at each stage of the oil product unloading unit is considered, and a logical scheme of emergency situations in this unit is constructed.The main hazards include the following: excess pressure in the tank above the critical value boundary, mechanical and corrosive wear of the tank truck, operating personnel errors, influence of external factors, leakage, overturning of the tank truck, formation of explosive and fire hazardous mixtures inside the tank truck, spillage of oil products, explosion, fire inside the tank truck, evaporation of the strait, fire of the strait, creation of explosive and fire hazardous mixture over the strait, explosion over the strait, destruction of building structures, equipped, injury, burns to people and the spread of the affected area outside the gas station.Recommendations on the prevention of emergency situations when unloading oil products from a tanker at gas stations and the actions of gas station employees in the event of their occurrence are developed.Наибольшей потенциальной опасностью технологической схемы автозаправочной станции (АЗС) является нарушение герметичности автоцистерны с нефтепродуктами на территории АЗС. Это может привести к взрыву паров топлива над проливом и пожар пролива, а также взрыв и пожар внутри автоцистерны. В этих случаях зона действия поражающих факторов аварии может быть распространена даже за пределы территории АЗС. Основными причинами возникновения аварийных ситуаций на АЗС являются: отказ в работе средств контроля и противоаварийной защиты; превышение технологических параметров процессов выше критических значений; нарушение норм технологических режимов; механический и коррозионный износ оборудования; ошибки ремонтного и обслуживающего персонала; действия внешних факторов.Целью данной работы является анализ причин возникновения и вероятного сценария развития аварий при разгрузке нефтепродуктов на автозаправочных станциях и разработка рекомендаций по предупреждению этих опасных ситуаций.Рассмотрен детальный анализ условий возникновения и развития аварии на каждой стадии узла разгрузки нефтепродуктов и построена логическая схема чрезвычайных ситуаций в этом блоке.К основным опасностям относятся следующие: превышение давления в цистерне выше границы критических значений, механический и коррозионный износ автоцистерны, ошибки обслуживающего персонала, влияние внешних факторов, нарушение герметичности, опрокидывания автоцистерны, образование взрывопожароопасной смеси внутри автоцистерны, пролив нефтепродуктов, взрыв, пожар внутри автоцистерны, испарения пролива, пожар пролива, создание взрывопожароопасной смеси над проливом, взрыв над проливом, разрушение строительных конструкций, оборудования, травмирование, ожоги людей и распространение зоны поражения за пределы АЗС.Разработаны рекомендации по предупреждению чрезвычайных ситуаций при разгрузке нефтепродуктов из автоцистерны на автозаправочных станциях и действий работников АЗС в случае их возникновения.Найбільшою потенційною небезпекою технологічної схеми автозаправної станції (АЗС) є порушення герметичності автоцистерни з нафтопродуктами на території АЗС. Це може спричинити вибух парів палива над проливом і пожежу проливу, а також вибух і пожежу усередині автоцистерни. У цих випадках зона дії уражаючих факторів аварії може бути розповсюджена навіть за межі території АЗС. Основними причинами виникнення аварійних ситуацій на АЗС є: відмова у роботі засобів контролю і протиаварійного захисту; перевищення технологічних параметрів процесів вище критичних значень; порушення норм технологічних режимів; механічний і корозійний знос обладнання; помилки ремонтного і обслуговуючого персоналу; дії зовнішніх факторів.Метою даної роботи є аналіз причин виникнення та ймовірного сценарію розвитку аварій при розвантаженні нафтопродуктів на автозаправних станціях та розробка рекомендацій з попередження цих небезпечних ситуацій.Розглянуто детальний аналіз умов виникнення і розвитку аварії на кожній стадії вузла розвантаження нафтопродуктів та побудовано логічну схему надзвичайних ситуацій у цьому блоці.До основних небезпек відносяться наступні: перевищення тиску у цистерні вище межі критичних значень, механічний та корозійний знос автоцистерни, помилки обслуговуючого персоналу, вплив зовнішніх факторів, порушення герметичності, перекидання автоцистерни, утворення вибухопожежонебезпечної суміші всередині автоцистерни, пролив нафтопродуктів, вибух, пожежа всередині автоцистерни, випаровування проливу, пожежа проливу, створення вибухопожежонебезпечної суміші над проливом, вибух над проливом, руйнування будівельних конструкцій, обладнання, травмування, опіки людей та розповсюдження зони ураження за межі АЗС.Розроблено рекомендації з попередження надзвичайних ситуацій при розвантаженні нафтопродуктів з автоцистерни на автозаправних станціях та дій працівників АЗС у випадку їх виникнення
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