bluuebunny/crossref_metadata_2025_split huggingface dataset:
Work-Family Conflict and Burnout among Female Medical Doctors in Selected Hospitals Abuja
Authors: Ajet G S , Offong R E , Ajayi M P , Iruonagbe T C , Amoo E O 
Published: November 2019

Abstract
Burnout is a sign of long-range exhaustion and deteriorated challenge that affects the wellbeing and health of individuals; it cuts across gender and has no regional boundary. The study investigated the influence of work-family conflict on burnout among female medical doctors. Method of both quantitative and qualitative research techniques was employed. A structured questionnaire was distributed among female doctors in selected hospitals. The in-depth interview was conducted with one senior female medical doctor in each hospital visited. The hospitals were those whose management obliged us the permission for the interview among identified hospitals in Abuja, Nigeria. Data were analysed using univariate bivariate and multivariate statistical techniques. For the in-depth interview, data were analysed using content analytic procedure. Individual items on three burnout categories were included in the analysis on a 7point scale. Regression model was used to analyse work-family conflict and burnout and it is statistically significant. The result indicated that emotional exhaustion only burnout factor hat predicts work-family conflict. A One-way Anova model was also used to discover the significant difference in the number of practice years an emotional exhaustion between groups. A descriptive mean also indicated that 0-5years of practice duration had the lowest mean and are more likely to experience emotional exhaustion. The study concluded that female doctors go through emotional exhaustion which is a major aspect in burnout. Also, female doctors at the earliest stage of their career experienced burnout unlike those at the latest stages.
Mathematical modeling of thermal processes in small-size DC electric machines
Authors: Pisarevsky Yu V , Borisova A I , Burkovsky V L , Yu Pisarevsky A , Fursov V B , Laschenov D P 
Published: November 2019

Abstract
This article considers small-size electric machines used in various fields of technology, from medical electrical equipment to complex mechatronic systems as part of spacecraft. To obtain satisfactory weight and size parameters of electric machines, it is necessary to take into account many factors that limit the possibility of reduction the machine size. The high energy of modern permanent magnets (250 - 300 kJ/m3) makes it possible to obtain the best weight and dimensons indicators in the designs of brushless direct current machines with excitation from permanent magnets, taking into account the influence of thermal processes.
On optimization hydro-generator parameters by NSGA-II
Authors: Gulay S , Verkhovtsev D 
Published: November 2019

Abstract
This paper demonstrates the method of optimizing the location and size of the distributed generators with the aim of reducing active power loss by changing the state of the existing tie and sectionalizing switches on the distribution network. A new algorithm is proposed to solve the distribution network reconfiguration problem based on the Runner-root Algorithm (RRA). In the first stage, the Runner-root Algorithm is applied to solve the reconfiguration problem, and the next stage of optimizing the new distribution network configuration takes into account the influence of the location and the size of the distributed generators. The calculation results show that the proposed method can simultaneously solve the problem of optimizing the location and size of distributed generators when reconfiguring the distribution network. The results of the comparison with other studies in the same distribution network system 69 nodes showed that the proposed method is highly effective and can be used for reference in the process of optimizing the operating mode of a distribution network.
Technique for optimization of diagnostic parameters composition for power systems objects
Authors: Pavlov P , Fandeev V , Aukhadeev A , Litvinenko R , Butakov V 
Published: November 2019

Abstract
A technique is proposed for optimization the composition of diagnostic parameters based on a combination of heuristic algorithms with the method of linear integer programming. The solution obtained using the heuristic algorithm with relatively small consumption of computational resources is taken as an initial one for optimization or checking the optimality of the composition of parameters using the linear integer programming method. The combination of a heuristic algorithm with the method of linear integer programming saves significant computational resources when searching for the optimal solution. The technique is aimed at minimizing costs when creating diagnostic support for monitoring performance and failure detection when considering the serviced and reconstructed electronic devices and equipment of power systems.
Simulation of high-voltage equipment electromagnetic radiation
Authors: Ignatev N I , Silin N V 
Published: November 2019

Abstract
The article is devoted to problems of simulation an electromagnetic field distribution near high-voltage power equipment. A radiating model of the power autotransformer 500 kV is presented. This model includes sizes and relative positioning of the autotransformer’s case and radiating elements, different constructions and earth existence, materials properties. The elements and constructions, located near the high-voltage equipment, such as cooling radiators, wireline passes, additions to lead-in wires, auxiliary columns, support for bus wire fastening, fire extinguisher system, concrete partitions are considered. Models of an electrical power object which contains above-mentioned elements and constructions are developed. The models are used for calculation electromagnetic field distribution on the electrical power object. Pictures of electromagnetic field distribution on a real electrical power object are calculated and presented in the form of direction patterns. Influence of the separate elements and constructions on the form of the directional pattern of the electrical power object model is estimated both in a form and in absolute values of electric-field strength of vertical polarization. The results achieved might be used at diagnostics of the high-voltage power equipment by electromagnetic control method.
K-nearest neighbor method for power transformers condition assessment
Authors: Tanfilyeva D V , Tanfyev O V , Kazantsev Y V 
Published: November 2019

Abstract
Reliable power supply is the most crucial task of every power utility company, making power transformers one of their chief assets. Thus, detection of power transformers abnormal condition is of high importance. Most general and approved tool of condition assessment is Dissolved Gas Analysis (DGA) of transformer insulation liquids. The identification task in fact implies conventional pattern recognition of measured parameters and their classification. The majority of prevalent classification and recognition methods require a priori knowledge of classes and symptoms, probability distribution laws and density functions, etc. This paper describes application of two fault recognition methods – Bayesian classifier and k-nearest neighbours (KNN) algorithm. Studies have shown that KNN tool allows flexibility for concentration limits adjustment with operation conditions’ altering and has a high condition classifying accuracy.
Development of the theory and methods for calculating the rational operation modes of electric traction equipment of urban electric transport
Authors: Aykhadeev A , Idiyatullin R , Kisneeva L , Zalyalov R , Pavlov P , Litvinenko A 
Published: November 2019

Abstract
The article considers the process of converting electrical energy into targeted mechanical motion of electric stock during the implementation of all technological conditions of the production system of urban electric transport. The aim is to confirm the proposed scientific hypothesis that the operation modes of electric traction equipment are formed under the influence of a complexly organized electric thrust process and are the basis of its topological structures. The theoretical study carried out on the basis of the methodological analysis of the theory of electrical equipment, the theory of automatic control and automated electric drive, the theory of electric traction, the theory of motion construction, the systematic approach and the synergistic paradigm resulted in the formulated scientific concept (theoretical system), which identifies the process of electric traction as a system consisting of five levels that are hierarchically related and solve an individual specific task of developing the electric vehicle motion. The obtained theoretical system will allow developing the general theory of electric traction of urban electric transport by improving its methodological foundations and can find practical application when developing methods for calculating its rational modes of operation.
On the possibility of unification of synchronous motors with permanent magnets with asynchronous motors of general application
Authors: Strashko Alexander 
Published: November 2019

Abstract
The use of modern high-coercive permanent magnets in synchronous motors allows one not only to unify the design and technology of their fabrication with asynchronous motors of general application, but also to significantly increase the efficiency of electric drives of production equipment and quality of technological processes. The performed studies have led to the conclusion that this problem is effectively solved by reconstructing only the active part of the rotor of an induction motor.
Thermal conductivity modeling for composite polypropylene / vapor grown carbon fibers
Authors: Stepashkina A S , Tsobkallo E S , Moskaluyk O A , Yu Egorov M 
Published: November 2019

Abstract
According to the melt technology a polymer composite material based on polypropylene (PP) matrix and vapor grown carbon fibers (VGCF) as a filler was obtained. The dependences of the thermal conductivity on the filler mass fraction and temperature were experimentally obtained. In this article we demonstrate that the heat-conducting properties of the material don’t depend on the sample geometry and the dependences of the thermal conductivity on temperature and the filler mass fraction have a nearly linear character. It is established that when the VGCF mass fraction is more than 5%, the obtained composite material can be used to remove heat in electrical and electronic devices. Such materials have antistatic properties at the VGCF mass fraction 5%. The model based on the multichannel conduction was built and the task was solved. This method allows the heat transfer process description in composite materials with sharply differing heat-conducting properties of components taking into account such material characteristics as density, heat capacity, heat conduction and heat velocity in the material.
Improving the energy efficiency of frequency converters in networks of limited power
Authors: Churkin A A , Churkin B A , Savelieva I S 
Published: November 2019

Abstract
The article discusses a method for improving the energy efficiency of a two-unit frequency converter with an active voltage rectifier using an input LCL filter. Studies are conducted on the basis of an asynchronous motor. The article presents the simulation results in the Matlab Simulink package. Improving the energy efficiency of elements of the energy system is especially important in networks of limited power.
The influence of some natural factors on efficiency of operation of photoelectric elements under conditions of North Kazakhstan
Authors: Utegulov B B , Utegulov A B , Koshkin I V , Koshkina A I 
Published: November 2019

Abstract
The article presents the results of studies of some natural factors on the productivity of solar cells. In the study of output characteristics, the dependence of the generation of electrical energy on the number of incident solar radiation on photoelectric converters was obtained. From these characteristics it can be precisely said that the dependence of the operating current and voltage on solar radiation and temperature is not completely proportional. The humidity exerts the most insignificant influence on the solar installation. Particular attention should be paid to the dependence of voltage changes on the magnitude of solar radiation. It has been revealed that in low power plants the influence of temperature will not play an extremely important role on the output parameters, but at higher powers the losses associated with the increase in temperature will be correspondingly large. The generation of electrical energy from solar photoelectric converters depends on many factors, not only on incoming radiation, but also on aspects such as: the location of the solar transducer to the sun, pollution of solar cells, icing and snow cover of solar cells. In this scientific work was made an analysis of the effect of snow precipitation on the productivity of solar cells in the characteristic climatic conditions of North Kazakhstan.
Mathematical modeling of MHD processes in the casting of aluminum alloys in electromagnetic mold
Authors: Pervukhin M V , Timofeev V N , Usynina G P , Sergeev N V , Motkov M M , Gudkov I S 
Published: November 2019

Abstract
The article contains the overview of mathematical modeling of electromagnetic field and magnetohydrodynamic process of the ingot moulding during casting into the electromagnetic mold. We have formulated the system of equations describing the molding process. The authors describe the principle of casting into the electromagnetic mould to produce small diameter ingots, as well as the results obtained. This article gives the analysis of magnetohydrodynamic flows in the area of molding and their impact on the resulting ingot. It is shown that the intensity of the MHD processes is influenced by the frequency of the supply voltage and the shape of the crystallization front. The calculations are based on favorable conditions for the formation of a homogeneous, fine-grained structure. The experimental studies were conducted using samples of aluminum alloy 01417.
Reversible frequency converters in the composition of multimotor electric drives
Authors: Ganiev R 
Published: November 2019

Abstract
The article deals with the modeling of multi-motor electric drives based on reversible frequency converters (RFC) based on Autonomous voltage inverters and current inverters in the program Matlab 13. The possibilities of energy recovery using keys with twoway conductivity are shown. The interaction of reversible converters with the supply network, as well as the influence of recovery processes on the capacitor of the DC link is presented. A comparative analysis of three schemes using RFC based on autonomous current inverters (ACI) and voltage inverters (AVI). Technical solutions are proposed to direct the braking energy into the supply network and reduce the voltage level on the capacitor plates without loss of energy efficiency
Pulse generator of a polygonal design with a high rate of voltage
Authors: Bystrov A , Lantsev D 
Published: November 2019

Abstract
The paper discusses the results of experimental studies of pulsed generators based on a drift diode with a sharp recovery (DSRD) and inductive energy storage of standard and polygonal structures. For the first time the generator of a polygonal design is presented. It is shown that when the generators are working on an active-capacitive load, the rate of voltage rise on it at the generator of a standard construction is lower. The generator of a polygonal design has high characteristics for the rate of increase of voltage and its amplitude. This article will discuss the effect of capacitive load on the rate of voltage rise and the way to increase it.
A non-stationary model of the AC plasma torch
Authors: Obraztsov N V , Kadyrov A A , Surov A V , Subbotin D I , Popov V E 
Published: November 2019

Abstract
Modelling of a single-phase two-channel AC plasma torch with a calculated power of 1.1 kW at a current value of 6 A is presented in the paper. A model of the plasma torch operation on argon at a flow rate of 0.69 g/s is considered. A 35-millisecond operation of the plasma torch has been simulated. The obtained temperature distributions and arc voltage drops allow us to evaluate the simulation results at a qualitative level.
Semiconductor generator of high voltage nanosecond pulses for plasma technologies
Authors: Korotkov S V , Smorodinov V V , Aristov Yu V , Bystrov A V , Zhmodikov A L , Korotkov D A 
Published: November 2019

Abstract
A generator of nanosecond pulses is discussed in the paper. The main output parameters of the generator are as follows: the maximum output voltage amplitude is 20 kV, the output current strength is 300 A, the maximum frequency is 3 kHz, the output pulse rise time is 4 ns, the output pulse energy is 25 mJ. The generator is based on a current interrupter, which is an assembly of drift step recovery diodes (DSRD). Effective operation of the DSRD is provided by assemblies of IGBT-transistors connected in series, the operating voltage of each assembly is 4 kV. It is shown that the generator can be effectively used for purification of air from organic pollutants and for ignition of car spark-plugs.
Mathematical model of the short circuit process in the electrical network with self-recovering current-limiting device with a liquid metal
Authors: Kuznetsov A V , Yurenkov Y P 
Published: November 2019

Abstract
The article shows that the high speed and current-limiting properties of a self-recovering current-limiting device with a liquid metal cause interest in their use in power supply systems. However, the level of research, both in our country and abroad, does not allow to proceed to the creation of industrial designs of such kind of current-limiting devices. More research is needed. To study the process of a short circuit in the AC (an alternating-current network) proposed a mathematical model that allows precise, detailed and deployed to investigate their current-limiting properties. The model takes into account the resistance of the electric arc during the switching process. Period of the burning time of the arc can be divided into infinitely small areas, arc resistance each of which is assumed to be linear.
The system of trigeneration with binary cycle for use as an energy source for gas fuel
Authors: Abramovich B N , Bogdanov I A , Kopteva A V , Malarev V I 
Published: November 2019

Abstract
The article describes the relevance of the problem of increasing the efficiency of fuel and energy complexes, based on the energy strategy of Russia for 2030. A review of various methods of air cooling for a more intense combustion process in a gas turbine plant is carried out and the most optimal one is chosen. The paper presents a model of the system of automatic control of the air cooling of the heat exchanger of a gas turbine unit to ensure the conditions of the nominal mode of operation when weather conditions change.
Use of a turbine expander to generate electricity for own operation needs of a gas turbine unit at compressor stations of main gas pipelines
Authors: Stepanov O , Rydalina N , Antonova E 
Published: November 2019

Abstract
In order to save energy at compressor stations, it is proposed to use expander-generating units (EGU) to reduce gas pressure. An analytical justification for replacing a throttle by EGU is given. The results of economic calculation of electricity savings when using EGU are given. The scheme of gas turbine unit with EGU and gas heating before entering the combustion chamber is presented. When using this scheme, the cost savings for electricity purchase is 83%.
Optimization technique for allocation scheme and low head hydroelectric power plant parameters
Authors: Sidorenko G I , Togo I 
Published: November 2019

Abstract
The article deals with the formalized description of low head hydroelectric power plants and their cascades with the choice of technical and geometrical parameters’ optimization, optimality criteria and constraints that are imposed at optimization parameters. The goal of the work is to develop a method for optimizing the parameters of low head hydroelectric power plants, including determination of hydroelectric stations’ location in the cascade, and to create a computer model to solve the problem. Methods of mathematical modeling and methods of multicriteria optimization have been used. Formalized description of the problem of optimal placement of hydroelectric power plants on the river network is given. The following criteria are considered as optimality criteria: economic criterion (net present value, construction and operation costs), environmental criterion and energy criterion. The main parameters of low head hydroelectric power plants have been identified; the interrelations of these parameters with optimization criteria have been established. The method has been developed for optimizing the parameters of a hydroelectric power plant at their determined location on a watercourse. The following results have been obtained. 1) The problem of optimization of hydroelectric stations on a watercourse, which takes into account the energy, economic, social, environmental, water-energy and resource features of the region, is formulated and presented in the form of mathematical model. 2) Using the graph network and the corresponding vector values of the function, Pareto and minimax solutions of this problem have been found. 3) With the determined location of hydroelectric power station on a watercourse, method and algorithm have been developed for optimizing technical and geometrical parameters. Technical and economic models of the energy process at the hydroelectric power plant, as well as technical and economic models of the main and auxiliary equipment and facilities (dams, hydroelectric power station buildings, etc.) have been developed.
Minimization of active capacity losses in cable power lines of 0.4 kV using optimally distributed compensating devices at petrochemical and oil refining enterprises
Authors: Tumaeva E V , Kuzin S S , Gavrilov E N 
Published: November 2019

Abstract
We propose a solution for optimization problem of minimizing active power losses for radial power supply scheme by optimal distribution of a given amount of reactive power between the compensating devices. We considered a single-line power supply scheme for a group of pumps of technological installation at a chemical plant. A mathematical model of the optimization problem is compiled by the criterion of active losses minimum in power lines depending on the reactive power flow. We obtained the distribution of optimal values of reactive power between the compensating devices of asynchronous motors for the specified tg φ. Quantitative and cost estimations are given for reducing the active power losses in power transmission lines when using capacitor plants, the reactive power of which is optimally distributed. We investigated the influence of starting currents on a circuit when asynchronous motor and capacitor installation are simultaneously turned on. We established the absence of an additional dynamic load on the supply lines.