bluuebunny/crossref_metadata_2025 huggingface dataset:
Spectroscopic detection of coronal plasma flows in loops undergoing thermal non-equilibrium cycles
Authors: Pelouze Gabriel , Auchère Frédéric , Bocchialini Karine , Froment Clara , Parenti Susanna , Soubrié Elie
Published: December 2019

Context. Long-period intensity pulsations were recently detected in the EUV emission of coronal loops and attributed to cycles of plasma evaporation and condensation driven by thermal non-equilibrium (TNE). Numerical simulations that reproduce this phenomenon also predict the formation of periodic flows of plasma at coronal temperatures along some of the pulsating loops.

Aims. We aim to detect these predicted flows of coronal-temperature plasma in pulsating loops.

Methods. We used time series of spatially resolved spectra from the EUV imaging spectrometer (EIS) onboard Hinode and tracked the evolution of the Doppler velocity in loops in which intensity pulsations have previously been detected in images of SDO/AIA.

Results. We measured signatures of flows that are compatible with the simulations but only for a fraction of the observed events. We demonstrate that this low detection rate can be explained by line of sight ambiguities combined with instrumental limitations, such as low signal-to-noise ratio or insufficient cadence.
NuSTAR/XMM–Newton monitoring of the Seyfert 1 galaxy HE 1143-1810
Authors: Ursini F. , Petrucci P.-O. , Bianchi S. , Matt G. , Middei R. , Marcel G. , Ferreira J. , Cappi M. , De Marco B. , De Rosa A. , Malzac J. , Marinucci A. , Ponti G. , Tortosa A.
Published: December 2019

Aims. We test the two-corona accretion scenario for active galactic nuclei in the case of the “bare” Seyfert 1 galaxy HE 1143-1810.

Methods. We perform a detailed study of the broad-band UV–X-ray spectral properties and of the short-term variability of HE 1143-1810. We present results of a joint XMM–Newton and NuSTAR monitoring of the source, consisting of 5 × 20 ks observations, each separated by 2 days, performed in December 2017.

Results. The source is variable in flux among the different observations, and a correlation is observed between the UV and X-ray emission. Moderate spectral variability is observed in the soft band. The time-averaged X-ray spectrum exhibits a cut-off at ∼100 keV consistent with thermal Comptonization. We detect an iron Kα line consistent with being constant during the campaign and originating from a mildly ionized medium. The line is accompanied by a moderate, ionized reflection component. A soft excess is clearly present below 2 keV and is well described by thermal Comptonization in a “warm” corona with a temperature of ∼0.5 keV and a Thomson optical depth of ∼17 − 18. For the hot hard X-ray emitting corona, we obtain a temperature of ∼20 keV and an optical depth of ∼4 assuming a spherical geometry. A fit assuming a jet-emitting disc (JED) for the hot corona also provides a nice description of the broad-band spectrum. In this case, the data are consistent with an accretion rate varying between ∼0.7 and ∼0.9 in Eddington units and a transition between the outer standard disc and the inner JED at ∼20 gravitational radii.

Conclusions. The broad-band high-energy data agree with an accretion flow model consisting of two phases: an outer standard accretion disc with a warm upper layer, responsible for the optical–UV emission and the soft X-ray excess, and an inner slim JED playing the role of a hard X-ray emitting hot corona.
Prospects for measuring Mercury’s tidal Love numberh2with the BepiColombo Laser Altimeter
Authors: Thor R. N. , Kallenbach R. , Christensen U. R. , Stark A. , Steinbrügge G. , Di Ruscio A. , Cappuccio P. , Iess L. , Hussmann H. , Oberst J.
Published: December 2019

Context.The Love numberh2describes the radial tidal displacements of Mercury’s surface and allows constraints to be set on the inner core size when combined with the potential Love numberk2. Knowledge of Mercury’s inner core size is fundamental to gaining insights into the planet’s thermal evolution and dynamo working principle. The BepiColombo Laser Altimeter (BELA) is currently cruising to Mercury as part of the BepiColombo mission and once it is in orbit around Mercury, it will acquire precise measurements of the planet’s surface topography, potentially including variability that is due to tidal deformation.

Aims.We use synthetic measurements acquired using BELA to assess how accurately Mercury’s tidal Love numberh2can be determined by laser altimetry.

Methods.We generated realistic, synthetic BELA measurements, including instrument performance, orbit determination, as well as uncertainties in spacecraft attitude and Mercury’s libration. We then retrieved Mercury’sh2and global topography from the synthetic data through a joint inversion.

Results.Our results suggest thath2can be determined with an absolute accuracy of ± 0.012, enabling a determination of Mercury’s inner core size to ± 150 km given the inner core is sufficiently large (>800 km). We also show that the uncertainty ofh2depends strongly on the assumed scaling behavior of the topography at small scales and on the periodic misalignment of the instrument.
Development of technology of disinfectants based on soda production waste
Authors: Salmanova Elina , Araslanova Lyasan , Tuktarova Iren , Nazarov Alexey
Published: December 2019

The main requirements for the development of fundamentally new disinfectants with a high level of efficiency are to reduce toxicity by increasing the technical and economic indicators in the technology of their application. In this paper, an innovative composition of a disinfectant based on iodine monochloride in the complex of waste production of soda and polyvinylpyrrolidone is proposed. The dependence of stability and antibacterial activity of the developed disinfectant is studied. High indicators of stability (3 years) and antibacterial activity were obtained on the example of Staphylococcus aureus (S. aureus), Enterococcus fecalis (E. fecalis), Pseudomonas aeruginosa (P. aerginosa), Bacillus subtilus (B. Subtilis No. 12) at the concentration 0.027-0.055, DS versus commercial drug Zhavilar. The antibacterial activity of the disinfectant DS, DS-1 is maintained up to 0.0044-0.0088 for Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans and Escherichia coli and exceeds the efficiency of the commercial drug Betadine by 8-28 times. Thus, the developed formulations are highly effective, while low-toxic and safe for the environment and humans.
Eco-friendly technology of manufacturing complex products made of composites
Authors: Ignatov Aleksey , Subkhankulov Rustam
Published: December 2019

Numerous studies in application of modern composite materials show that their advantages can be successfully implemented in manufacturing «smart» products. This study proposes an improved technological method of manufacturing multilayer environmentally friendly products with a variable cross section, which allows us to expand the possibilities of using modern polymer composite materials (PCM). The technology allows manufacturing products of the most complex geometric shapes, such as wind turbine blades. The aim of the study is the technological support of engineering production in the manufacture of multilayer products of variable cross section made from PCM. Scientific novelty consists in identifying the patterns of implementation and management of the manufacturing process of multilayer products of variable cross-section, and establishing the influence of structural and technological parameters of the manufacturing process on their operational characteristics. The relationship between the pressure of a hot directed air stream and the volume fraction of pores in the hardened material of a multilayer composite product with a variable cross section during layer-by-layer application is investigated. During the study, fundamental and applied principles of mechanical engineering technology, material resistance, adhesion theory, mathematical statistics tools and software were used to process the results of the experiment. Based on the results of laboratory studies, a methodology has been developed for effective prediction of pore content in the manufacturing of composite products. The introduction of the presented technology and the corresponding original methodology into production will reduce the complexity and energy costs of manufacturing composite products, improve their quality and reduce the impact of toxic components from composite materials on workers.
Spent sulphite liquor utilization by xylose-assimilating yeast pachysolen tannophilus, capable of bioethanol producing
Authors: Bolotnikova Olga , Bazarnova Julia , Aronova Ekaterina , Mikhailova Natalia , Bolotnikova Tatiana , Pu Jing
Published: December 2019

The xylose-assimilating capacity of yeast Pachysolen tannophilus to utilize sugars in spent sulphite liquor samples (pulp mill waste) with a different concentration of hexoses and pentoses was studied. The consumption of hexoses (D-glucose, D-mannose, D-galactose) and pentose (D-xylose) in such substrates reached 90.0-97.5% and 49.12-67.45%, respectively. The ethanol production from sugars in spent sulphite liquor by different strains of the yeast P. tannophilus was demonstrated. The maximum specific rate and ethanol yield reached 9.32-11.45 g l-1 and 0.28-0.37 g g sugars-1, respectively. Thus, the principle possibility of using xylose-assimilating P. tannophilus yeast to obtain bioethanol from sulfite liquor with a different ratio of hexoses and pentoses was proved. According to theoretical calculations, this method will provide up to 42.6 liters of ethanol from 100 kg of sulfite liquor containing 55.6% D-xylose, 24.7% D-glucose, 8.7% D-mannose, 7.6% D-galactose, 3.7% L-arabinose. A future-oriented perspective on bioethanol production from pulp and paper industry wastes by the yeast P. tannophilus is considered.
Thermo-economic Assessment of the Possible Desalination Processes for the Second Block of Bushehr Nuclear Power Plant
Authors: Sadeghi Khashayar , Ghazaie Seyed Hadi , Sokolova Ekaterina , Fedorovich Evgeniy , Shirani Amirsaeed
Published: December 2019

Nowadays, the problem of supplying fresh water to scarcer regions of the world is still acute. The seawater desalination has been touted as the main solution of closing the water gap in the Middle East and North Africa. However, seawater desalination is expensive and energy-intensive and influences the environment, extremely. Using nuclear power is a viable alternative energy resource to decrease the set of problems of consuming fossil fuels in the desalination plants. Iran, which is located in the arid belt of the eastern hemisphere, as a member state of IAEA (International Atomic Energy Agency) has announced his interest in the implementation of dual-purpose nuclear desalination in the existing nuclear power plant of the country. The Bushehr nuclear power plant is the first commercial nuclear reactor in the Middle East and can be used as a multi-purpose atomic complex to meet the demand for energy and supply of water to arid regions in the south of the country. This paper performs a thermo-economic assessment study for different desalination strategies in the second block of Bushehr NPP.
The impact of small and medium-sized businesses in Cameroon on the development of the energy system
Authors: Nyemb Nyemb Bekoume , Novikova Olga
Published: December 2019

The development of Cameroon’s power grid is linked to the electricity supply and demand market. In recent years, small and medium-sized businesses, due to their rapid development, begin to significantly affect the balance of consumption. According to the results of the analysis, the paper presents the classification of the share of electricity consumption by small and medium-sized enterprises by industry. The forecast of self-generation of electric energy by enterprises from biogas is estimated.
Conceptual approaches for building a balanced portfolio of projects in oil and gas companies in exploration and production sector
Authors: Molchanov Konstantin , Romasheva Natalia
Published: December 2019

Uncertainties such as price volatility, supply and demand, global warming, technological progress, geopolitical situation, force the capital-intensive oil and gas sector to create a flexible portfolio of projects to proactively respond to changes. In an increasingly complex and uncertain environment, oil and gas companies around the world face continued pressure. It has become difficult to make strategic decisions and build long-term plans, so it has become vital to have a balanced portfolio. We suggest that in order to achieve the goals and maximize profitability, companies need to develop indicators for balanced portfolio, which will allow to evaluate the portfolio and rank the current and potential projects in order to create flexibility with minimal risk. In the article, we analysed modern approaches and benchmarked companies` tools for portfolio management, current situation in industry, identified risks and indicators for evaluation. We received the tool for quantitative evaluation for portfolio.
Laboratory stand for designing industrial KNX networks on Siemens logo! Communication modules
Authors: Kartuzov Aleksandr , Kartuzova Tatyana , Seliverstova Lyudmila
Published: December 2019

Industrial automation networks based on the EIB / KNX protocol are very popular among European companies in the construction of intelligent buildings, but they are of little interest in high school education and currently professional specialists are not trained to use them. Developing the KNX‐based automation system simulator for the training of engineering students is required. We have designed and installed a KNX simulator for engineering students training on smart systems. The presented stand was developed on Siemens LOGO! Basic with CM KNX communication modules. The modules of simulator and KNX software programming tool ETS are explained. Besides, sample scenarios for engineering students to enhance and implement their projects are given.
Mathematical modeling of parameters of solar modules for a solar power plant 2.5 MW in the climatic conditions of the Republic of Cuba
Authors: Guerra Daniel , Iakovleva Emiliia
Published: December 2019

Today, the problem of increasing the efficiency of solar panels is relevant. The parameters and characteristics of solar modules are analyzed using computer modeling methods. Many contemporary scientists are busy with the problem of modeling different solar modules in different conditions. This paper presents the results of mathematical modeling in the Matlab software environment of photoelectric modules of the DSM-240-C model. Based on the obtained simulation results, it seems possible to study the characteristics of solar modules depending on various external and internal factors – temperature and illumination. Also in this paper, we present the results of a full-scale experiment of photovoltaic modules that are part of a 2.5 MW solar power plant operating in the Republic of Cuba. The results of the experiment confirm the effectiveness of the simulation.
The influence of external climatic factors on the accuracy of the forecast of energy consumption
Authors: Shklyarskiy J.E. , Batueva D.E.
Published: December 2019

The object of the study is the territory, which is characterized by household and production load, and their characteristic tendencies of changes in the volume of electricity consumption, and therefore it is necessary to create forecast models that take into account the influence of external climatic fac-tors and their contribution to the forecast of energy consumption of the ob-ject. In the work, theoretical methods and experimental studies were used, consisting in a scientific analysis of trends in changes in power consumption depending on changes in factors, methods of mathematical statistics, statis-tical samples, factors and data from the weather service. During this study, external climatic factors that influence the process of changing the energy consumption of an object and their degree of influence on changing con-sumption were determined. To improve the accuracy of forecasting, it is pro-posed to break the data into working days and days off, since consumption in these periods is of a different nature.
Predictive model of the dependence of the cost of insulation on thermal characteristics
Authors: Gamayunova Olga , Radaev Anton , Petrichenko Mikhail , Bogdanivics Raimond
Published: December 2019

In the market of building materials today there is a large selection of various thermal insulation materials, differing in cost, thermal conductivity and other characteristics. This article describes the predictive model of the cost of insulation from thermal characteristics, such as: thickness, thermal conductivity, (average) density, water absorption and combustibility group. The coefficient of determination was used to assess the quality of the obtained economic-mathematical model. The described predictive model can be effectively used to solve problems associated with determining the optimal characteristics of insulation by the criterion of minimizing cost.
Diagnostics of life support systems with limited statistical data on failures
Authors: Senchenkov Valentin , Absalyamov Damir , Avsyukevich Dmitriy
Published: December 2019

The authors suggest an approach to determine the technical conditions of life support systems of public buildings in conditions of significant uncertainty of statistical information on failures. To improve the re1iabi1ity and increase the resources of life support systems, maintenance and repair strategies are proposed according to the actual state, which implies the availability of objective diagnostic information. The essence of methods for constructing images of system failures based on training procedures is revealed, the latter being founded on the theory of nonparametric statistical analysis. The image is understood as a formalized description of the failure as an element of the system diagnosis model. The solution of image synthesis problem is given when the orthogonal trigonometric basis is applied in the recurrent relations implementing the learning process. The specific case assumes the existence of data on ranges of diagnostic parameter change at all failures of the investigated object. A modification of the training procedure is performed to build images of failures of life support systems of the latest generation when it is possible to find the ranges of changes in diagnostic parameters only in operational state. The modification consists of the formation and application of an orthonormal binary basis in recurrent relations. There is an example of image constructing of one of the ventilation and air conditioning system failures of a public building on the basis of a modified training procedure.
Real gas state equations comparative analysis for low-temperature calculations
Authors: Sokolov Mikhail , Sadovsky Nikolay , Zuev Anatoly , Gileva Lyubov , Nguyen Minh Hai
Published: December 2019

In this paper, various real gas state equations are considered and their comparative analysis is carried out. The following state equations are studied in the work: Benedict-Webb-Rubin modification equation, Ridlich-Kwong Real Gas equation, Peng-Robinson Real Gas equation, and the modified Ridlich-Kwong real gas state equations proposed by Barsuk S.D. We have made a direct comparison of these calculation methods with most accurate identification. In addition, the paper analyzes the equations features, with applicability limits definition of each state equations. For the chosen one, as the most universal and exact equation, the calculations were made for the liquid phase and the real gas two-phase state. Based on the data obtained, polynomials were developed for various parameters depending on the gas temperature, which can later be used to build various mathematical models. Our conclusions show main advantages of selected equation for real gases and the reasons for choosing it for modeling low-temperature heat and mass transfer processes.
Comparative efficiency of applying heat pumps within the system of disposal of the condensation heat of heat machines for heating ice arenas
Authors: Kondrashov Aleksey , Egorov Mikle , Kovalenko Ivan , Litvinova Nadezhda , Lavrovskaya Natal’ya , Krectunova Irina
Published: December 2019

The analysis of the application of two energy-efficient technologies for air heating of ice arenas is considered, such as the use of heat pumps and a system for partial utilization of heat of condensation of heat engines. The actual energy costs during the operation of two systems are studied, such as the consumption of heat and electricity from heat and power supply organizations, as well as the costs of modernization. The weaknesses and positive aspects of the studied systems for air heating of ice arenas are revealed. Comparison of the calculated data obtained as a result of calculations with the actual data obtained in the research institution in which the study is carried out. An example of actual effective modernization of existing engineering systems is shown, as a result of which the energy efficiency of existing systems is increased. Additionally, we have performed the calculation of reducing thermal pollution with introduction of the investigated systems.
Software-modeling complex for automation tests of low and medium power turbo electric tests
Authors: Kavalerov Boris , Kilin Grigory , Zhdanovskiy Evgeniy
Published: December 2019

There are many problems connected with use of gas turbine units for electricity generation. The main problem is the gas turbine unit inefficient operation as a synchronous generator drive. To ensure the required quality of the generated electricity, which is largely determined by the nature of the transient processes of gas turbine unit, further improvement of control algorithms for automated control systems of gas turbine unit is required. In solving this problem, gas turbine unit should be considered in conjunction with other subsystems and units, for gas turbine power plants - this is, first of all, the electric generator and electric power industry in general. The process of tuning a gas turbine power plant control system is part of the test. Particularly time-consuming operations are manual tuning of the control system during experimental design and operational tests. Therefore, we propose to use a software-modeling complex, on the basis of which it is possible to obtain a neural network mathematical model of a gas turbine electro station and conduct its tests. In this case, in the process of testing the control system, the setup procedure is first performed on a mathematical model, then the settings obtained are checked using semi-bench testing, the final check of the decisions taken is carried out on a full-scale test bench, and data on the direct operation of a gas turbine power plant are also taken into account.
Prediction of hydrogen sulfide emission from an energy dissipation chamber and assessment of its distribution in the ambient air
Authors: Telyatnikova Anna , Fedorov Sviatoslav , Stolbikhin Iurii , Korneeva Elena
Published: December 2019

Wastewater transport in sewer networks contributes to the formation and emission of fetid and toxic sewage gases into the environment, one of which is hydrogen sulfide. The emission of gases can have a significant impact on the environment and health of maintenance workers and city residents. The object of the research is the study of the process of hydrogen sulfide emission in the energy dissipation chamber (EDC). The method of two-stage mathematical modeling in the program of finite element analysis ANSYS CFX is applied for the research. Two models have been created, the first one simulates the internal space of the EDC structure itself, and the second one simulates the EDC manhole and the volume of the surrounding air next to it. Mathematical dependences of hydrogen sulfide concentration change at three sections inside the structure are obtained for incoming wastewater flow velocities V = 1 m/s, 1.5 m/s and 2 m/s. The critical flow velocities at which the maximum single threshold limit value will exceed 1 m/s and the threshold limit value of the working area will exceed 1.52 m/s are determined. The methodology for solving the problem of assessing the impact of the EDC object on the environment is formed. The results of the study can be applied in the design of structures for a preliminary assessment and prediction of the impact of a wastewater facility, as well as the selection of the most favorable hydraulic regime.
Numerical characteristics of a centrifugal compressor with a low flow coefficient
Authors: Yablokov Aleksey , Yanin Ivan , Sadovskyi Nikolay , Kozhukhov Yuri , Nguyen Minh Hai
Published: December 2019

The study presents the simulation results of the viscid gas flow in low flow coefficient centrifugal compressor stages. The problem is solved in a stationary formulation using the Ansys CFX software package. The numerical simulation is carried out on three ultrahigh-pressure model stages; two stages have blades of the classical type impeller and one stage is of the bodily type. The value of the conditional flow coefficient is 0.0063 to 0.015. As part of the study, block-structured design meshes are used for all gas channel elements, with their total number being equaled as 13–15 million. During the calculations a numerical characteristic was validated with the results of tests carried out at the Department of Compressor, Vacuum and Refrigeration Engineering of Peter the Great St. Petersburg Polytechnic University. With an increase of inlet pressure as a result of a numerical study, it was found that for a given mathematical model the disk friction and leakage coefficient (1 + βfr + βlk) is overestimated. The analysis of flow in labyrinth seals has shown an increase of total temperature near the discs by 30–50 °С, nevertheless this fact did not influence gas parameters in the behind-the-rotor section. The calculation data obtained with finer design mesh (the first near-wall cell was 0.001 mm) is identical to those obtained with the first near-wall cell 0.01 mm mesh.
Numerical Simulation of Viscous Effects of Oil on the Capacity of Oil Booms
Authors: Thi Kim Chi Thai
Published: December 2019

The potential risk of oil spills is constantly increasing, which required special techniques, equipment and effective response plans as well. Oil booms is the most common equipment used for spilled oil clean-up. However, due to different reasons such as extreme hydrological conditions, unreasonable design or poor handling, the failure of booms can happen. The loss rate of boom is acceptable if it is small enough. In the present paper, the behavior of oil with different viscosity around the oil boom is numerically studied using ANSYS FLUENT software. The shape evolution of oil slicks is presented. The loss rates in given conditions are also determined.
Development of a system for automated control of oil transportation in the Arctic region to prevent the formation of paraffin deposits in pipelines
Authors: Kopteva Alexandra , Koptev Vladimir , Malarev Vadim , Ushkova Taisiya
Published: December 2019

The paper introduces a unique methodology of preventing and controlling the formation of paraffin deposits in oil pipelines, which is a matter of urgency in regions with negative temperatures, including the Arctic regions. The paper presents the configuration and specific parameters of the developed measuring unit. The proposed measuring unit is capable of detecting the formation of a paraffin layer during its early stages and predicting its composition. Simultaneous use of two radioisotope sensors allows increasing the performance capabilities of the measuring unit, namely to detect the formation of a paraffin layer in the early stages and to issue a signal to amplify the control signal to control the oil pipeline paraffinisation. In addition, the use of a radioisotope unit instead of a single sensor will increase the accuracy of component-wise flow rate measurement, by making an allowance for paraffin deposits formation. The use of customized information processing algorithms also allows determining oil viscosity with high accuracy. The paper deals with an optimization of a system for automated control of a promising method of electric heating via the skin-cables, wherein safety factors of up to 36% are currently used, i.e. in most cases, 1/3 excess electric power is generated. The safety of using the radioisotope measuring technique is proven.
Automatic diagnostic of transmission lines based on ultraviolet inspection
Authors: Nguyen Phuong , Dudkin Sergey , Kong Chenzai
Published: December 2019

Evaluation of the technical condition, reliability of the insulation of electrical equipment is an actual problem. It is confirmed by experience and statistics of operation at power plants and railway facilities. The combination of an unmanned aerial vehicle with UV-camera and software based on neural networks allows us to effectively diagnose long power lines. To increase the effectiveness of non-contact inspection of power lines, especially in hard-to-reach areas, more compact mobile solutions should be used which include an UV-camera and an unmanned aerial vehicle (UAV). The aircraft market currently has significant growth, that allows to bring the diagnostic experience to a new level by attaching an UV-camera to an aerial device, which will have a tremendous effect on examining long power lines. But we faced one problem related to the absence of any scientific basis for this method of examination, so it was decided to conduct experiments in a laboratory of St. Petersburg Polytechnic University. The results of experiments are presented in the work.
Electric power supply management of the construction site in the interests of facilitating electrical safety
Authors: Polyukhovich Maxim , Burlov Vyacheslav , Mankov Victor , Bekbayev Amangeldy
Published: December 2019

A critical resource in construction work is electricity. Various problems that can lead to a breakdown of the electric power supply to the construction site can arise during its active operation. The basis of the activity is the decision of the person. Activity is based on the model. The dependence of human activity on electrical energy has formed the need to ensure uninterrupted electric power supply. To solve the complex problem of electric power supply, it is necessary to develop a theory. A properly constructed theory has three levels, three components: methodology, methods, technology. The decision maker (DM) perceives the world around him and carries out his activities through processes. A process is an object in action at a fixed purpose. A constructive methodology should form the condition for the existence of a process with which the DM works. The goal of research is to select and justify the conditions for the existence of the electric power supply process in the interests of guaranteed achievement of the goal of the industrial safety.
Radiation thermal effect of a fire spilling fuel-air mixtures on a person
Authors: Penner Yana , Yakovlev Vyacheslav , Popov Nikita , Antonova Margarita , Borodiņecs Anatolijs
Published: December 2019

In the modern world, it is especially important to provide the population and industries with energy, which is necessary to maintain a consistently high quality of life. Often, the process of generating energy is associated with a certain risk to personnel and the public when using various types of fuel, often with fire hazardous properties. For each fire damaging factor, for example, for thermal radiation, toxicity of combustion products, smoke, and elevated temperature, the probability of human injury can be calculated. In this paper, the probability of a person being damaged by thermal radiation in a fire spilling a fuel-air mixture is calculated. A spill fire begins by igniting the vapors of spilled hydrocarbon fuel on an open surface. The calculation was carried out according to three methods, one of which takes into account the movement of a person away from the epicenter of the fire. The dependence of the heat flux density on the distance from the center of the fire is given. Based on calculations of the safe distance from the center of the fire and the values of thermal radiation using the Matlab software environment, the optimal method for determining the probability of human injury in case of a fire spill of an oil product was selected, and it was also concluded that it can be used in case of using high-energy fuel.
3D-MODELS AS A METHOD FOR REFLECTING VOLUME AND SPATIAL PARAMETERS OF OIL-CONTAMINED SITES
Authors: Mukhametshina Elvina , Aitov Ibragim
Published: December 2019

Today oil companies are trying to solve the urgent problem associated with the low efficiency of remediation work in oil-contaminated areas. Difficulties are caused by the lack of spatially ordered ideas about where and how pollution is distributed, what is its concentration and volumetric parameters in soils. The indicated problem entails an irrational waste of finance. As a rule, the return on funds spent does not exceed 30%. Obviously, the time has come to apply new approaches. We offer a technique for representing contaminants in the form of 3D models and tabular systematization of their concentrations and volumes. Scaling tabular information determines the color content of volumetric models. The described technique allows the differentiation of areas and their parts into reclamation groups. They focus on targeted use of allocated finances. Tabular systematization and spatially ordered representations of research results produce a synergistic effect. It manifests itself in obtaining a more accurate assessment of the condition of oil-contaminated sites, increasing the efficiency of restoration, the efficient use of finance.
Optimization of parameters for diesel shaft speed control system
Authors: Markov Vladimir , Furman Victor , Plakhov Sergey , Sa Bowen
Published: December 2019

This work presents a fuel supply electronic control system (model ESUVT.01) developed by Dizelavtomatika (Saratov) for the D50 (6 CHN 31.8/33) locomotive diesel engine manufactured by Penzadieselmash. In this system, the fuel supply process is controlled by a high-speed electro-hydraulic valve installed in the high-pressure line of the fuel system. A set of electrically controlled high pressure fuel pumps (mode 4ETN.03) with electro-hydraulic valves for the diesel was manufactured. This system can also control the engine speed. It was noted that the best quality indicators of the speed regulating process are provided by the PID control law. It was shown that for a diesel with high inertia, it is advisable to use the PI control law. Experimental studies were conducted to assess the influence of structure and parameters of this control system on the dynamic qualities of this diesel engine. The object of bench testing was a 1-PDG4D-type diesel-generator from the above-mentioned diesel engine and MPT-84/39 traction generator. The dependences of the duration of the transient process, the overspeed and the period of natural oscillations of the regulated parameter on the PI controller parameters were obtained. The necessity of optimizing the coefficients of proportional (P) and integral (I) components of the PI control law was confirmed. A method for optimizing the coefficients of proportional and integral components of the PI control law was proposed. The optimized coefficients for the transient acceleration process of the diesel engine according to the locomotive characteristic were obtained.
Static load characteristics in the presence of high harmonics
Authors: Skamyin Aleksandr , Vasilkov Oleg
Published: December 2019

The article presents the issues of static load characteristics construction in the presence of high harmonics. Mathematical equations for power calculations in the presence of high harmonics are proposed. Reactive power is calculated at the fundamental frequency based on minimizing the computational error of electronic energy meters and providing minimum costs to ensure maximum degree of reactive power compensation using condenser batteries. The dependences between distortion power and voltage are constructed according to the results of measurements at the laboratory stand. Such dependencies allow us to identify the nature of harmonic distortion, to develop measures for minimizing the distortion power and consumer contribution to the voltage distortion.
Numerical modeling of induction heating systems with load of azimuthal periodicity
Authors: Mannanov Emil , Galunin Sergei , Shatunov Alexey
Published: December 2019

The paper presents developed numerical modelling methodology of induction heating problems of disks with a simple and complex profile in 3D for calculating the coupled electromagnetic and thermal tasks in the parametric design language (ANSYS APDL). We demonstrate that the developed tools can be used for products of various sizes, as well as for other metal engineering components using the example of local electromagnetic processing of a metal disk and a diaphragm spring. The authors used development for parametric research and design of induction heaters. The described methodology has particular specificity, due to which it is possible to expand the scope for a number of engineering units with azimuthal periodicity property.
The potential for reducing TPP water consumption through the use of heat pumps
Authors: Treshcheva Milana , Treshchev Dmitry , Anikina Irina , Skulkin Sergei
Published: December 2019

Largest part of consumed water resources in Russian Federation is related to energy sector; accordingly, we need to develop measures to ensure their rational use. This paper analyzes the potential for reducing water consumption of thermal power plants by applying heat pumps in the condenser cooling system of a steam turbine plant. The calculations were performed for two CCGT-450 power units with three main options for technical water supply systems. The greatest environmental and economic effects are provided by the use of heat pumps at TPPs with a once-through water supply system. Utilization of all low-grade heat of the condenser cooling system of a steam turbine plant is irrational due to an increase in energy consumption for TPP own needs. With a further growth of tax rates for water intake from surface water bodies, positive effect of application of heat pumps in the condenser cooling system of a steam turbine plant will increase by an order of magnitude.
Weniger Kohlenhydrate in der Therapie des Diabetes?
Authors: Bosy-Westphal Anja , Müller Manfred J.
Published: December 2019

Lifestyle-Diäten mit einer Einschränkung des Kohlenhydratverzehrs (Low Carb, Paleo, ketogen) erfreuen sich insbesondere zur Kontrolle des Körpergewichts zunehmender Beliebtheit. Bei Patienten mit Typ-2-Diabetes sollen sie nicht nur zur Gewichtsreduktion beitragen, sondern auch zu einer verbesserten Einstellung der Glykämie und einer Senkung des Insulinbedarfs führen. Was sind die Vor- und Nachteile einer Reduktion der Kohlenhydrataufnahme bei Patienten mit Typ-2-Diabetes? Wenn die Kohlenhydrate ersetzt werden, wovon sollte stattdessen mehr verzehrt werden? Kann eine kohlenhydratreiche Diät bei Patienten mit Typ-2-Diabetes heute noch empfohlen werden? Der Beitrag versucht, diese Fragen in Kürze zu beantworten und rückt den Fokus der Diskussion weg von der reinen Betrachtung der Makronährstoffrelation hin zur Bedeutung der Kohlenhydrat- und Fettqualität und einer individualisierten Ernährungstherapie. Darüber hinaus bieten sowohl die Stratifizierung metabolischer Phänotypen des Prädiabetes als auch die differenzierte bioinformatische Analyse von Ernährungsmustern anstelle von rein korrelativen nährstoffbasierten Auswertungen neue Ansätze für die Ernährungsforschung.
Development of a voltage controlled resistor for use in a self-balancing resistance bridge
Authors: Tadić A. , Reyes Borunda A. , Ray M. W.
Published: December 2019

We report on a simple design for a voltage controlled resistor that can operate in a continuous range from ∼50 Ω to over ∼100 kΩ. The device consists of a light emitting diode (LED) placed near a photocell. Varying the voltage across the LED changes its brightness, which, in turn, changes the resistance of the photocell. The resistance of the photoresistor is measured by calibrating the output of a nearby phototransistor against the photoresistor resistance, allowing for an independent measurement of the resistance. The performance of the device is tested in the context of a temperature measuring system involving a Wheatstone bridge.
Microwave heating and spark plasma sintering as non-conventional synthesis methods to access thermoelectric and magnetic materials
Authors: Siebert Jan P. , Hamm Christin M. , Birkel Christina S.
Published: December 2019

The development of new—cheaper, more efficient, more sustainable, and more reliable—functional materials with useful properties calls for ever-improving, smart, and innovative synthesis strategies. A multitude of inorganic compounds are already used as energy materials, i.e., electrodes, catalysts, permanent magnets, and many more are considered highly promising for these and similar applications. Innovative synthesis techniques are developed, resulting in new compounds as well as known ones with unique structures and morphologies. Here, we will discuss the nonconventional solid-state methods, microwave heating and spark plasma sintering, highlighting their potential for the preparation of a plethora of inorganic compounds. Thermoelectric and magnetic materials are chosen as two examples of energy materials that are relevant for several different areas, such as waste heat recovery, energy generation, and refrigeration. The goal is to provide an overview of the inorganic compounds, ranging from intermetallics to chalcogenides and oxides, which have been prepared using these two nonconventional synthesis techniques. Furthermore, the reaction conditions as well as key properties regarding their thermoelectric and magnetic behavior are summarized.
Accurate phase retrieval of complex 3D point spread functions with deep residual neural networks
Authors: Möckl Leonhard , Petrov Petar N. , Moerner W. E.
Published: December 2019

Phase retrieval, i.e., the reconstruction of phase information from intensity information, is a central problem in many optical systems. Imaging the emission from a point source such as a single molecule is one example. Here, we demonstrate that a deep residual neural net is able to quickly and accurately extract the hidden phase for general point spread functions (PSFs) formed by Zernike-type phase modulations. Five slices of the 3D PSF at different focal positions within a two micrometer range around the focus are sufficient to retrieve the first six orders of Zernike coefficients.
Flying wing flow separation control by microsecond pulsed dielectric barrier discharge at high Reynolds number
Authors: Niu Zhong-guo , Liu Jie , Liang Hua , Xie Li-ke , Su Zhi
Published: December 2019

In this study, a microsecond pulsed dielectric barrier discharge (μs-DBD) plasma actuator is utilized to improve the aerodynamic performance of a flying wing. The wind tunnel experiments were conducted by the μs-DBD plasma actuator at a high Reynolds number (Re = 2.61 × 106). The effects of discharge position and pulse frequency on the flow control performance were studied by force measurements. The particle image velocimetry test was used to reveal the influence of plasma actuation on the detailed velocity field at the suction side of the flying wing. Results show that plasma actuation can significantly improve the aerodynamic performance of the flying wing under high Reynolds number. The best flow control effect is obtained when the plasma actuator is mounted near stagnation point (0.1% C). There is an optimal excitation frequency (100 Hz) at Re = 2.61 × 106 (corresponding to the wind speed of 70 m/s), at which the flow instability can be effectively excited. In the optimal situation, the relative improvement of the maximum lift coefficient reaches 20.51% and the stall angle is delayed by 6°. The flow control performance is mainly achieved at the outer part of the wing because the flow separation develops gradually from the wing tip to the root. These experimental results contribute to the free flight test in the wind tunnel and the flight test in real air conditions.
Phase evolution and thermal stability of high Curie temperature BiScO3-PbTiO3-Pb(Cd1/3Nb2/3)O3 ceramics near MPB
Authors: Lan Zhencheng , Chen Kaiyuan , He Xiafeng , Zhou Shuo , Zheng Xiande , Liu Jia , Fang Liang , Lei Xiuyun , Wang Dawei , Peng Biaolin , Liu Laijun
Published: December 2019

Piezoelectric and ferroelectric ceramics with a high Curie temperature (Tc) have attracted much attention owing to their applications in severe environments. In this work, phase structure and dielectric, ferroelectric, and piezoelectric properties of (0.975 − x)BiScO3-xPbTiO3-0.025Pb(Cd1/3Nb2/3)O3 (BS-xPT-PCN) ceramics (x = 0.58–0.64) were studied. A composition-induced structural transformation occurs from the rhombohedral to tetragonal phase through an intermediate monoclinic phase with the increasing PT concentration. The relationship between the structure and electrical properties of the system was discussed. The BS-xPT-PCN system near the morphotropic phase boundary (MPB) (x = 0.62) exhibits excellent piezoelectric and ferroelectric performances with d33 = 508 pC/N, kp = 56%, and Pr = 40 μC/cm2. The high-temperature piezoelectricity of the sample with MPB (x = 0.62) was characterized by an in situ XRD. The excellent thermal stability of the crystal structure and the piezoelectric property indicate that the BS-xPT-PCN system is a promising candidate for high-temperature piezoelectric applications.
Schottky barrier height of epitaxial lattice-matched TiN/Al0.72Sc0.28N metal/semiconductor superlattice interfaces for thermionic energy conversion
Authors: Nayak Sanjay , Acharya Shashidhara , Baral Madhusmita , Garbrecht Magnus , Ganguli Tapas , Shivaprasad S. M. , Saha Bivas
Published: December 2019

Since the initial development of semiconductor heterostructures in the 1960s, researchers exploring the potential of artificially structured materials for applications in quantum electronic, optoelectronic, and energy conversion devices have sought a combination of metals and semiconductors, which could be integrated at the nanoscale with atomically sharp interfaces. Initial demonstration of such metal/semiconductor heterostructures employed elemental polycrystalline metal and amorphous semiconductors that demonstrated electronic tunneling devices, and more recently, such heterostructures were utilized to demonstrate several exotic optical phenomena. However, these metal/semiconductor multilayers are not amenable to atomic-scale control of interfaces, and defects limit their device efficiencies and hinder the possibilities of superlattice growth. Epitaxial single-crystalline TiN/Al0.72Sc0.28N metal/semiconductor superlattices have been developed recently and are actively researched for thermionic emission-based waste heat to electrical energy conversion, optical hyperbolic metamaterial, and hot-electron solar-to-electrical energy conversion devices. Most of these applications require controlled Schottky barrier heights that determine current flow along the cross-plane directions. In this Letter, the electronic band alignments and Schottky barrier heights in TiN/Al0.72Sc0.28N superlattice interfaces are determined by a combination of spectroscopic and first-principles density functional theory analyses. The experimental EF(TiN)-EVBM(Al0.72Sc0.28N) at the interfaces was measured to be 1.8 ± 0.2 eV, which is a bit smaller than that of the first-principles calculation of 2.5 eV. Based on the valence band offset and the bandgap of cubic-Al0.72Sc0.28N, an n-type Schottky barrier height of 1.7 ± 0.2 eV is measured for the TiN/Al0.72Sc0.28N interfaces. These results are important and useful for designing TiN/Al0.72Sc0.28N metal/semiconductor superlattice based thermionic and other energy conversion devices.