bluuebunny/crossref_metadata_2025 huggingface dataset:
Pollution emission evolution from composite and metal formation in Foundry Industry
Authors: Fayomi O S I , Ayoola A A , Morounfoluwa J , Akinwumi I I
Published: November 2019

The consumption of steel is a major indicator of the rate at which a country is developing. Emerging economies such as China and India markets have developed on the back of products such as steel, aluminum, and alloys. This development have not received much fanfare because of the environmental pollution incurred by the production of this products and at that rapid scale. This paper aims at studying the environmental impact of steel production by identifying the various forms in which pollution occurs in the metal production industry. This study limits itself to understanding the impact of gases evolved from the metal foundry be it from the foundry furnace or the metal mold cast. The study indicates that there is a correlation between the quality of mold cast and the rate of gas emission.
Development of a short time model for predicting chloride ingress into normal and pozzolanic concrete
Authors: Ikumapayi C M
Published: November 2019

One of the major origins of corrosion in concrete reinforcing steel is chloride ion penetration. This process deteriorates concrete structures in many parts of the world. Chloride can penetrate into concrete structures mainly through diffusion and absorption. A good percentage of research work has been carried out on diffusion mechanism and the process even though slow is a well understood one. Conversely, few research work has been reported concerning absorption mechanism of chloride ion penetration in concrete. This is a fairly rapid transport process whose mechanism needs to be understudied. For this study, concrete cube specimens containing 100%OPC, 12%BLA and 12%GSA of mix 1:2:4 were prepared. The workability of the various mixes was obtained through slump and compaction factor tests. The hardened cubes, 150 mm³, were thereafter immersed in sodium chloride (NaCl) solution for the specified durations. Compressive strength, absorption and spray tests were carried out on the designed specimens at 28, 56 and 90 days. Numerical models were developed using data obtained from the various tests to predict the depth of chloride penetration into normal and pozzolanic concrete under the condition used in this study. The developed models indicate that absorption has substantial effect on chloride ingress. The models’ outputs further propose that the thickness of concrete cover in structures exposed to chloride attack should be greater than the present recommended values in use. However, thickness of concrete cover has practical limits based on the design and analysis, consequently, partial replacement of cement with pozzolans (Bamboo Leaf Ash and Groundnut Shell Ash) should be adopted.
The need for the inclusion of entrepreneurship in our Nigerian architectural education
Authors: Nnaemeka-Okeke R C , Ugwu C C , Okafor C N
Published: November 2019

Nigeria’s emerging economy is driven by young people who have discovered opportunities in new technologies that has given rise to entrepreneurial skills and enterprises. Architecture as a discipline and profession is technology driven and there is an urgent need to bridge the gap between architectural education and practice to make our young architects more relevant with this current trend. There is a strong observation that the existing curriculum structure for teaching and practicing architecture is inadequate to address the challenges of today. The aim of this research was to establish the importance of the inclusion of entrepreneurship in the architectural curriculum in the schools of Architecture. We hypothesized that inclusion of entrepreneurship in architecture teaching curriculum will increase the development of entrepreneurial culture; promote enterprise; sensitize students in the diversification in architecture; and foster entrepreneurial mind-set through theory and practice. A survey was carried out using 150 participants made up of 100 students and 30 lecturers drawn from three universities (federal, state and private) and 20 practicing architects in Enugu Metropolis using a convenient sampling method. Using Chi-square statistics to test the hypotheses, all the hypotheses were confirmed. The results were discussed, and recommendations made.
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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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.
Improving the efficiency of frozen soils excavation using high-frequency vibration
Authors: Ilyukhin A V , Marsov V I , Marsova E V , Syetina T A , Dzhabrailov K A
Published: November 2019

Loosening machines occupy a special place for mechanization of earth-moving. Despite rapid development of new methods for soils excavation and specialized machines, the mechanical method of their destruction by rippers in the near future will remain the most effective in most operating conditions. This is explained by relative simplicity of rippers design, wide scope and versatility of their applications, high productivity and low cost per unit of work performed. Rippers play a special role while excavating rocky and frozen soils, and in the latter case, the issue of loosening is particularly relevant, since the area occupied by permafrost is 58% of our country, and together with seasonally frozen soils it covers almost 90% of its territory. One of the most rational ways to intensify the processes of loosening are high-frequency oscillations of the ripper working body in the sonic range using resonant magnetostrictive vibrators. A new approach to the design of a loosening process control system is needed, which covers a range of issues related to development of new principles and methods of automation. Only in this way it will be possible to significantly improve the technical and economic indicators of loosening machines, to avoid influence on them of significant fluctuations in quantitative and qualitative characteristics of soil. Analysis of loosening processes showed that earthworks in heavy soils using traditional methods and mechanisms of loosening are not sufficiently effective first of all due to insufficient use of energy potential of loosening machine. Therefore, one of the most important tasks that needs to be solved when introducing the methods of vibro-loosening of frozen soils is to increase energy efficiency of these processes. Since traditional methods for excavation of frozen soils require substantial energy costs of 5–6 kW per m3, the introduction of the proposed system makes it possible to reduce these costs by 15–20%.
Flywheel energy storage systems for autonomous energy systems with renewable energy sources
Authors: Kovalev K , Poltavets V , Kolchanova I
Published: November 2019

One of the main problems of introducing energy systems using renewable energy sources is its dependence on climatic conditions during the year. The instability of incoming energy leads to significant fluctuations in power, voltage and frequency of alternating current in the network. Modern technologies do not yet allow achieving sustainable energy systems, which are driven only by 100% usage of renewable energy. Nowadays production of high-quality electricity is possible with parallel connection of traditional sources and using energy storage systems. This article presents design solutions for application of flywheel energy storage systems (FESS) in autonomous energy systems used by foreign companies. We describe the design of superconducting FESS with magnetic HTS suspension with stored energy of more than 5 MJ, which is the first in Russia.
Dependence of power supply systems reliability on the type of redundancy
Authors: Baburin S V , Zyrin V O , Kovalchuk M S
Published: November 2019

The paper deals with power supply systems reliability of gas pumping compressor stations. Comparative analysis of the system reliability with hot, warm and cold reserve is processed. The modelling was performed using the software complex “ARBITR”. Dependability measures were determined for different types of power supply systems with different set and number of power sources including centralized power supply system, autonomous power stations and others. Recommendations on the use of various types of redundancy for various structures of power supply systems are given.
Employment of a centrifugal turbine for the utilization of the natural gas energy within the process of pressure reduction
Authors: Fokin G A , Smirnov M V , Zabelin N A
Published: November 2019

There is no doubt that turboexpander generation technology has considerable benefits such as reduction of CO2 emission and maintaining autonomous power supply for gas letdown stations and some technological processes. In spite of the abovementioned advantages of this technology its further development faces challenges due to: 1. long payback period of plants with conventional turbines; 2. significant annual fluctuations of gas inlet parameters; 3. high demands of conventional turbines for working fluid cleanliness. In current study the bladeless centrifugal reaction turbine was considered in order to struggle with abovementioned constraints. The investigated turbine is a variation of so-called Segner wheel known for centuries. Its efficiency is lower comparing with the conventional rotary machines, but remains beneficial within the specific conditions of turboexpander application. A comparison of the proposed turbine and axial transonic one was provided within a wide range of pressure ratios as typical operating conditions. The advantages of the investigated centrifugal turbine such as ability to generate comparable power as conventional ones while having lower cost and higher mud and erosion resistance has been highlighted.
Pseudo random binary signal for MIMO frequency response identification of a magnetically levitated rotor system
Authors: Nevaranta Niko , Vuojolainen Jouni , Sillanpää Teemu , Pyrhönen Olli
Published: November 2019

High-speed machine technology with magnetically levitated rotor systems has become interesting solution in modern compressor, pump and turbo applications. Often, the commissioning of such machines is system identification-based with injected artificially generated excitation. In this paper a statistically uncorrelated PRBS design is proposed for multi-input multi-output MIMO system that gives the possibility to utilize same PRBS signal for all inputs. The proposed routine is validated with an experimental high-speed generator with active magnetic bearings (AMBs). The obtained frequency responses are validated by comparing the results with the mathematical model.
NLH calculation of the influence the inlet nonuniformity on the fan parameters
Authors: Popov Grigorii , Volkov Andrey , Goriachkin Evgenii , Baturin Oleg
Published: November 2019

The paper presents the results of numerical simulation of the effect of flow nonuniformities at the engine inlet on the working process of the engine fan. Flow nonuniformities is created by pushing the interceptor into the flow part of inlet device like as it is often done during field tests. The authors have created a numerical model capable of considering non-stationary pro-cesses in the fan using nonlinear harmonic analysis. As a re-sult, qualitative and quantitative estimates were obtained of the influence of overlapping of the inlet duct by the interceptor on the main parameters of the fan workflow. It is shown that the more the duct is blocked, the more its parameters are deteriorated. Moreover, the deterioration is not linear, but according to.
From resinous wood distillation to hydrogen energy (questions of the history of pyrogenation)
Authors: Aleshina Alena
Published: November 2019

Substantial contribution to development of electrical engineering was made in the 19th century. Indeed, in the early 19th century centralized gas lighting systems were established first in England, and then in the rest of Europe and North America, and then it was switched to electric lighting by 1880s. Before electricity became widespread and suitable for general public use, gas was the most popular method of indoor and outdoor lighting in cities. The article is devoted to the history of development of thermochemical technologies for the decomposition of wood and other carbon-containing materials (coal, oil, shale, peat) in order to obtain heat and related valuable products for various purposes. Special attention is paid to the development of gasification technologies of low-quality solid fuels; featuring periods of increasing demand for similar technologies and periods of a sharp decline. As a result of the analysis of world experience in the field of gasification technologies, it is shown that, generator gas theoretically can be used for energy purposes, for example to drive automobiles or internal combustion engines, to be the fuel of CHP plants of different capacity, as well as to be included into the schemes with fuel cells for the development of hydrogen energy.
The development of simulation complex of isolated power supply system functioning under principles of «microgrid»
Authors: Sosnina E N , Kryukov E V , Ivanov A V
Published: November 2019

It is necessary, while designing new and modernizing oexisting electricity supply system (SS), both to seek to improve uniformity of electricity load and to increase the generation of electricity due to an alternative energy source. These facts are contradictory in terms of practical implementation because of stochastic nature of wind power plant, solar panels etc. The only solution is the transition from centralized to decentralized development of power industry, which is based on aggregation of distributed energy resources (including renewable energy sources (RES) and the applying the principles of «Internet of Energy», «Virtual power plant », «Microgrid » etc.) The using of this approach for designing isolated power system could reduce high energy cost which was caused by transport component. Pilot operation of the same energy systems without preliminary studies has high technical and economic risks. For that reason, it required a developing of simulation complex modelling system’s work. The article includes scientific and technological solutions for designing simulation complex of isolated power system, which function in “microgrid” and consist of models of sources and energy storage devices. Dependence of energetic parameters for different input parameter have been obtained. The concept of hardware/software solution, which provide opportunity for testing and researching algorithms of control system, have been presented also.
Topological quantum weak antilocalization limit and anomalous Hall effect in semimagnetic Bi2−xCrxSe3/Bi2Se3−yTey heterostructure
Authors: Kanagaraj Moorthi , Yizhe Sun , Ning Jiai , Zhao Yafei , Tu Jian , Zou Wenqin , He Liang
Published: November 2019

Magnetic topological insulator hosts both a non-trivial surface band and quantum anomalous Hall effect when tuning the time reversal symmetry by various chemical doping into the system. Using molecular beam epitaxy, we have synthesized Bi2−xCrxSe3/Bi2Se3−yTey heterostructure, which was scrutinized via in situ angle resolved photoemission spectroscopy, ex situ x-ray diffraction, Raman, and x-ray photoemission characteristics analyzing techniques. We used the Hikami-Larkin-Nagaoka formula for quantifying the weak antilocalization limit in Bi2−xCrxSe3 and Bi2Se3−yTey non-magnetic layer coupling near the ferromagnetic transition temperature (∼7 K). A higher concentration of Cr (1.5%) in Bi site leads to bulk carrier density for entire cooling temperature with a bandgap of 85 meV. The proximity effect of Te doped Bi2Se3 with magnetic topological insulator degrades the ferromagnetic response for this heterostructure. Our study suggests that the manipulation of disorder free magnetic top layer and fine tuning of spin–orbit coupling strength in the bottom topological insulator can be helpful to understand the high temperature quantum anomalous Hall effect towards relativistic quantum electronics applications.
An effective parametrization of gust profiles during severe wind conditions
Authors: van den Brink Henk W
Published: November 2019

A simple and effective parameterization for the profile of extreme wind gusts during severe wind conditions is presented. It is shown that the gust profile follows directly from the logarithmic wind profile. Also the uncertainty in the gust estimates can easily be determined from information of the average wind speed at two different heights. One specification of practical importance is that the maximum 3s-gust in a 10 min period at 10 m height is arithmetically equal to the average wind at 140 m. At larger heights the gusts are equal to the average wind speed at an easily determinable height that is a factor α (α > 1) higher. Validation over The Netherlands indicates that this rule applies to heights up to at least 200 m. This outcome is validated both over land and over sea, and is independent of surface roughness. The proposed parameterization reproduces the climatological values of the measured extreme wind gusts. Maximum gusts for individual winter months are better represented than for individual summer months. The mean error in the monthly winter maxima estimates is 5%.
Impact of discharge medication bedside delivery service on hospital reutilization
Authors: Patel Avni , Dodd Melanie A , D'Angio Richard , Hellinga Robert , Ahmed Ali , Vanderwoude Michael , Sarangarm Preeyaporn
Published: November 2019

Purpose

To evaluate the impact of a medication to bedside delivery (meds-to-beds) service on hospital reutilization in an adult population.

Methods

A retrospective, single-center, observational cohort study was conducted within a regional academic medical center from January 2017 to July 2017. Adult patients discharged from an internal medicine unit with at least one maintenance medication were evaluated. The primary outcome was the incidence of 30-day hospital reutilization between two groups: discharged patients who received meds-to-beds versus those who did not. Additionally, the incidence of 30-day hospital reutilization between the two groups was compared within predefined subgroup patient populations: polypharmacy, high-risk medication use, and patients with a principal discharge diagnosis meeting the criteria set by the Centers for Medicare and Medicaid Services 30-day risk standardized readmission measures.

Results

A total of 600 patients were included in the study (300 patients in the meds-to-beds group and 300 patients in the control group). The 30-day hospital reutilization (emergency department visits and/or hospital readmissions) related to the index visit was lower in the meds-to-beds group, but the difference was not statistically significant between the two groups (8.0% in the meds-to-beds group versus 10.0% in the control group; odds ratio, 0.78; 95% confidence interval, 0.45–1.37). There was no significant difference in the 30-day hospital reutilization related to the index visit between the control and meds-to-beds groups within the three subgroups analyzed.

Conclusion

There was no difference in 30-day hospital reutilization related to the index visit with the implementation of meds-to-beds service in the absence of other transitions-of-care interventions.
Role Models in Language Learning: Results of a Large-Scale International Survey
Authors: Muir Christine , Dörnyei Zoltán , Adolphs Svenja
Published: November 2019

Role models can exert considerable influence in shaping individuals’ values, attitudes, and beliefs. A large body of work in the social sciences has investigated the influence of celebrity role models, and in the context of education, several disciplines have a rich research history in this area (e.g. medical education). However, in the context of second language acquisition, research centred on role models has largely remained on the periphery. This study presents a large-scale international survey investigating the role models of English language learners. With data collected from 8,472 participants, analysis investigated whether these learners had English language role models, who the role models were and what characteristics learners valued in them, and investigated systematic variation among subgroups. Results showed that 68 per cent of respondents reported having an English language role model, and four key role model dimensions emerged: overall command of English, paralinguistic features, personal attributes and accent/variety of English. We argue that role modelling may be a highly influential component of the psychological context of second-language acquisition, and conclude by highlighting several valuable areas for future research.
Measuring Quality of Life in Female Genital Cosmetic Procedure Patients: A Systematic Review of Patient-Reported Outcome Measures
Authors: Sharp Gemma , Maynard Pascale , Hamori Christine A , Oates Jayson , Sarwer David B , Kulkarni Jayashri
Published: November 2019

Background

In the subspecialty of female genital cosmetic procedures, patient satisfaction and quality of life are key outcome measures. As such, valid and reliable patient-reported outcome measures (PROMs) examining these outcomes are essential.

Objectives

The authors sought to identify and scrutinize all PROMs developed for female patients undergoing genital cosmetic procedures.

Methods

The authors performed a systematic literature review utilizing MEDLINE, PreMEDLINE, Ebase, Embase, OVID, CINAHL, Cochrane Library, PsycINFO, PubMed, and Google Scholar to identify PROMs developed and validated for utilization in female genital cosmetic procedure patients. Instruments identified were assessed according to international guidelines for health outcome measures development and validation.

Results

The authors identified 50 outcome questionnaires employed in the female genital cosmetic procedure literature. Of these, 26 were ad hoc instruments (ie, had not been formally developed and tested) and 22 were generic instruments (ie, intended for use in broad groups of people, not only specific patient groups). Only 2 instruments have been validated in a female genital cosmetic procedure patient population. These were the Genital Appearance Satisfaction scale and the Cosmetic Procedure Screening Scale–Labiaplasty. Although both these scales had undergone fairly rigorous psychometric development and validation, both had content limitations.

Conclusions

There is a lack of specific, valid, and reliable satisfaction and quality-of-life PROMs in the field of female genital cosmetic procedures. Future research should involve the development of such measures to more accurately assess the outcomes and benefits of these procedures.
Lipid metabolic pathways converge in motor neuron degenerative diseases
Authors: Rickman Olivia J , Baple Emma L , Crosby Andrew H
Published: November 2019

Motor neuron diseases (MNDs) encompass an extensive and heterogeneous group of upper and/or lower motor neuron degenerative disorders, in which the particular clinical outcomes stem from the specific neuronal component involved in each condition. While mutations in a large number of molecules associated with lipid metabolism are known to be implicated in MNDs, there remains a lack of clarity regarding the key functional pathways involved, and their inter-relationships. This review highlights evidence that defines defects within two specific lipid (cholesterol/oxysterol and phosphatidylethanolamine) biosynthetic cascades as being centrally involved in MND, particularly hereditary spastic paraplegia. We also identify how other MND-associated molecules may impact these cascades, in particular through impaired organellar interfacing, to propose ‘subcellular lipidome imbalance’ as a likely common pathomolecular theme in MND. Further exploration of this mechanism has the potential to identify new therapeutic targets and management strategies for modulation of disease progression in hereditary spastic paraplegias and other MNDs.
Neural Patterns in Linguistic Cortices Discriminate the Content of Verbal Working Memory
Authors: Kowialiewski Benjamin , Van Calster Laurens , Attout Lucie , Phillips Christophe , Majerus Steve
Published: November 2019

An influential theoretical account of working memory (WM) considers that WM is based on direct activation of long-term memory knowledge. While there is empirical support for this position in the visual WM domain, direct evidence is scarce in the verbal WM domain. This question is critical for models of verbal WM, as the question of whether short-term maintenance of verbal information relies on direct activation within the long-term linguistic knowledge base or not is still debated. In this study, we examined the extent to which short-term maintenance of lexico-semantic knowledge relies on neural activation patterns in linguistic cortices, and this by using a fast encoding running span task for word and nonword stimuli minimizing strategic encoding mechanisms. Multivariate analyses showed specific neural patterns for the encoding and maintenance of word versus nonword stimuli. These patterns were not detectable anymore when participants were instructed to stop maintaining the memoranda. The patterns involved specific regions within the dorsal and ventral pathways, which are considered to support phonological and semantic processing to various degrees. This study provides novel evidence for a role of linguistic cortices in the representation of long-term memory linguistic knowledge during WM processing.