502 research outputs found
Place of manufacture diversification in cyclical development of the enterprise
The relevance of the researched problem is caused by the fact that diversification is one of the best options for reforming enterprises. The aim of the research: to consider changes in production of outputs in development cycles of the enterprise. This will help to reveal the nature of manufacture diversification. The leading method to the research of this problem is the system approach, which allows to elicit factors promoting formation of business mechanism of manufacture diversification under the conditions of volatile economic environment. The results of the research are: it is offered to enhance the existing classification of enterprises by nomenclative and technological characteristic, taking into account the specific nature of processing capacity. The materials of the research can be useful for control bodies of enterprises when taking constructive steps in the sphere of manufacture diversification and strategy development. © 2016 Erofeev and Smolin
Global gyrokinetic simulations of intrinsic rotation in ASDEX Upgrade Ohmic L-mode plasmas
Non-linear, radially global, turbulence simulations of ASDEX Upgrade (AUG)
plasmas are performed and the nonlinear generated intrinsic flow shows
agreement with the intrinsic flow gradients measured in the core of Ohmic
L-mode plasmas at nominal parameters. Simulations utilising the kinetic
electron model show hollow intrinsic flow profiles as seen in a predominant
number of experiments performed at similar plasma parameters. In addition,
significantly larger flow gradients are seen than in a previous flux-tube
analysis (Hornsby et al {\it Nucl. Fusion} (2017)). Adiabatic electron model
simulations can show a flow profile with opposing sign in the gradient with
respect to a kinetic electron simulation, implying a reversal in the sign of
the residual stress due to kinetic electrons. The shaping of the intrinsic flow
is strongly determined by the density gradient profile. The sensitivity of the
residual stress to variations in density profile curvature is calculated and
seen to be significantly stronger than to neoclassical flows (Hornsby et al
{\it Nucl. Fusion} (2017)). This variation is strong enough on its own to
explain the large variations in the intrinsic flow gradients seen in some AUG
experiments. Analysis of the symmetry breaking properties of the turbulence
shows that profile shearing is the dominant mechanism in producing a finite
parallel wave-number, with turbulence gradient effects contributing a smaller
portion of the parallel wave-vector
Peculiarities of educational environment at mining and metallurgical schools of the Urals
The relevancy of the issue under study stems from the contradiction between the need for a modern interpretation of the activities of mining and metallurgical schools, which had played a prominent role in the institutionalization of the vocational education environment as well as from moral “obsolescence” of research work results in this field. The goal of the article is the development of environmental indices of mining and metallurgical education of the Urals. The principal concept of research of this problem is the system approach, which allows considering the main peculiarities of the educational environment at mining and metallurgical schools of the Urals comprehensively. This article includes structurally significant characteristics of the educational environment at mining and metallurgical schools of the Urals. The contents of the article may be used for the purpose of modeling, designing and construction of an educational establishment (system) meeting the demands of the new communicational reality within the system of relations between education, industry, and social environment. © 2016 Chapaev, Erofeev and Dvořáková
Cleaning of niobium surface by plasma of diffuse discharge at atmospheric pressure
Elements composition of niobium surface before and after plasma treatment by runaway electron preionized diffuse discharge was investigated in atmospheric pressure nitrogen flow by means of an Auger electron spectroscopy. Surface characterizations obtained from Auger spectra show that plasma treatment by diffuse discharge after exposure of 120000 pulses provides ultrafine surface cleaning from carbon contamination. Moreover, the surface free energy of the treated specimens increased up to 3 times, that improve its adhesion property
Low resistance Cu[3]Ge compounds formation by the lowtemperature treatment of Cu/Ge system in atomic hydrogen
The research deals with the regularities for Cu[3]Ge compound formation under the low temperature treatment of a double-layer Cu/Ge system deposited on i-GaAs substrate in atomic hydrogen flow. The treatment of a Cu/Ge/i-GaAs system with layer thicknesses, respectively, of 122 and 78 nm, in atomic hydrogen with a flow rate of 10{15} at.·сm{-2} s{-1} for a duration of 2.5{-10} min at room temperature, leads to an interdiffusion of Cu and Ge and formation of a polycrystalline film containing stoichiometric phase Cu[3]Ge. The film consists of vertically oriented grains of dimensions 100-150 nm and has a minimum specific resistance of 4.5 [mu omega] сm. Variation in the treatment duration of Cu/Ge/i-GaAs samples in atomic hydrogen affects Cu and Ge distribution profiles, the phase composition of films formed, and the specific resistance of the latter. As observed, Cu3Ge compound synthesis at room temperature demonstrates the stimulative effects characteristic of atomic hydrogen treatment for both Cu and Ge diffusion and for the chemical reaction of Cu[3]Ge compound generation. Activation of these processes can be conditioned by the energy released during recombination of hydrogen atoms adsorbed on the surface of a Cu/Ge/i-GaAs sample
INFLUENCE OF OZONE THERAPY AND UTROZHESTAN ON HORMONE PRODUCING FUNCTION OF FETOPLACENTAL COMPLEX AT THE THREATENING PREMATURE BIRTH AND FETOPLACENTAL INSUFFICIENCY
We researched hormonal function of fetoplacental complex (FPC) in 180 pregnant women with threatening premature birth and chronic fetoplacental insufficiency including 90 patients who received ozone therapy in combination with Utrozhestan, 90 pregnant women who received traditional therapy, and 51 woman with an uncomplicated pregnancy (control group). Corrective and. stimulating effect of ozone therapy and. Utrozhestan. on hormonal function fetoplacental complex was revealed
Development of the recommendations on selection of glass-fiber reinforced polyurethanes for vehicle parts
© Research India Publications. Advanced polymer composites have essential features: high specific strength ratio, resistance to aggressive substances (water, fuel, oil, lubricants, weak alkalies and acids), wide operation temperature range (from -60 to +80 °C), sufficient durability (up to 10 years), high aesthetic qualities. The use of polymer composites for vehicle parts significantly reduces the curb weight of a vehicle, improves its dynamic behavior, increases its payload capacity, reduces its fuel consumption and emissions. The research was focused on the parts made of rigid glass-fiber reinforced polyurethane. The samples were made using the system based on polyol component А and isocyanate component B in a ratio of 1,75:1 (A:B). As a filler the glass fiber roving was used in the amount of 25 weight parts per 100 weight parts of the matrix component. The glass-fiber reinforced polyurethane parts were manufactured by spraying. The paper describes the comprehensive research of the glass-fiber reinforced polyurethane properties including the evaluation of thermal resistance, impact resilience, temperature resistance, Shore D hardness, acoustic absorption coefficient with the state-of-the-art test procedures and research equipment. The recommendations were developed to select glass-fiber reinforced polyurethanes for vehicle parts: for parts where the material is under high load during operation (temperature, impact resilience, etc.) it is recommended, whenever possible, to use the materials with larger thickness; for the parts where hardness is subject to special requirements – the materials with smaller thickness; during part production it is necessary to precisely carry out the operations of part manufacturing process to avoid any defects which are stress raisers and reduce the material strength
Application of surfacing using consumable electrode with an additional filler wire to ensure the required operational properties of pipeline valves
A promising way to ensure the required operational properties of pipeline valves with a significant increase in productivity and quality of surfacing during its manufacture is the introduction of anti-corrosion surfacing technologies using a consumable electrode with the supply of an additional filler wire. A solution to the optimization problem of the proposed surfacing technology is complicated by a large number of its parameters, therefor the task was solved in stages. At the first stage, the parameters of the arc interaction between the electrode and filler wire was determined, and at the second - the specific features of the formation of the surfacing bath with such interaction. A virtual study of the process of surfacing with Inconel 625 wires in argon on steel 09G2S was carried out. The influence of the thermal effect of the deposition mode parameters on the main metal is determined. It has been established that, due to the fact that the heat flux in the main metal is created mainly by the droplet stream of the deposited metal from the main arc at high currents, the diameter of the electrode wire guaranteeing its burning should be larger than the filler wire. © Published under licence by IOP Publishing Ltd
Study of effects of redispersable latex powders on hardening kinetics of cement-sand composites
Redispersable polymer powders act as boosters of the physical and mechanical properties in the cement-sand composite. For the studies the most typical redispersable polymer powders were used - Rhoximat PAV 22 and Rhoximat PAV 23 latex powders, by Rhodia. The analysis of the micrographs showed that the new formations of the cement rock had a pronounced needle-like form, and the cements with the additives were partially covered with the polymer film of the redispersable particles. The resulting polymer bridges and cords in the structure prevented growth of the cracks which were formed due to shrinkage and applied external force. Film-forming latex of redispersable powder can increase fracture energy of the cement-sand composite significantly. In view of this, of great significance is strength of the polymer itself. The higher strength polymer has, the greater force one should apply to fracture modified mixture. The basic components of Rhoximat PAV 22 and Rhoximat PAV 23 are vinyl acetate and vinyl versatate. Vinyl resins in the cement composites are known to develop a lattice which penetrates the structure formed by the cement gel, and, thus, act as an additional binder in the material
ТЕХНОЛОГИЧЕСКАЯ ПОТРЕБНОСТЬ В КОРРЕКТИРОВКЕ ПЛАНА ФОРМИРОВАНИЯ ПОЕЗДОВ
The number of freight cars in Russia has considerably increased lately (more than 1 mln units in 2011), but the rate of satisfied demands of customers for freightage has on the contrary reduced. The time of delivery is increasing. As there is no shortage in cars the problem resides in non-efficient operation of private car rolling stock. The capacity of reduction of delivery time should be considered through reducing staying idle time and delays under technical and loading operations rather than by increasing technical speed. So the problem of enhancement of freightage should be seen and approached firstly as an economic and technological process.According to technology in force the car traffic is organized in conformity with the plan of train making-up. But the plan, which is adopted for a full year period, is optimum for a certain assessed volume of car traffic. As a rule, it’s the most probable value of traffic density. And there are considerable fluctuations from and towards the average value during the year.In order to put the plan of train making-up in conformity with real traffic density it is proposed to implement the technology of prompt updating of train making-up plan and of selection of car traffic operation. The updating supposes the choice of a variant that permits to deliver all goods in time, depending on their logistics characteristics, and with minimum possible costs. It should be taken into account that the updating of train making-up plan at one station has a direct, and sometimes, negative impact on the plans of other stations of a rail network. In order to avoid negative effects it is necessary to compute critical max and min values of car traffic that allow maintaining the actual plan.The proposed planning and scheduling are based on a simulation model, that, processing data on the approaching trains, number of the cars within the local network and their logistics characteristics, results in scheduling the trains traffic towards destination point.The patterns of integrated computation are shown for departing routing and for through trains planning.Анализ экономических и технологических решений по оперативной корректировке плана формирования поездов. Основные элементы схемы выбора рационального варианта организации вагонопотоков при перевозке приватным подвижным составом. Предложена методика комплексного расчета плана для сквозных поездов и отправительской маршрутизации. Дается схема оперативного планирования поездной работы, которая с позиций экономики позволяет учесть требования компаний-операторов.
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