bluuebunny/crossref_metadata_2025_split huggingface dataset:
MEASUREMENT OF CO AND NO2 GAS CONCENTRATION'S BY MULTISENSOR MICROSYSTEM IN THE MODE OF PULSE HEATING
Authors: Reutskaya O. G. , Pleskachevsky Y. M. 
Published: July 2018

The most promising for mass use in gas analysis equipment are semiconductor gas sensors due to their high reliability, easy operation and relatively low cost. Power consumption in the single-sensor mode, constant heating is from 250 to 600 W average and in pulsed mode heating – ≤ 20 W. The aim of this work was to study the effectiveness of the pulsed heating for multisensor microsystems consisting of two sensors on the substrate of the nanostructured aluminum oxide, compared with the mode of constant heating.For sensitive layers were chosen compositions: SnO2+Pt+Pd at the first sensor of the microsystem and In2O3+Al2O3+Pt on the second. Measuring the sensor response in the pulse heating mode was carried out as follows. Power on each sensor microsystem was installed 1.3 mW. Then the short-term heating (theat.. = 5 s) was performed at the power 61 mW. The detected gases CO and NO2 with the concentration 200 ppm and 4 ppm, correspondingly, were submitted to the microsystem after 15 minutes. The resistance values for each of the sensor were fixed. According to the results determine the sensitivity (sensor response) the maximum value is after 60 s for the sensor with a sensing layer SnO2+Pt+Pd when exposed to CO was 670 %, and for the sensor with In2O3+Al2O3+Pt – 380 %.Advantages of using pulsed heating from the point of view of a power consumption multisensor microsystem mW-range and high performance sensors on substrates of nanostructured alumina were established.
DEVELOPMENT AND ADAPTATION OF VORTEX REALIZABLE MEASUREMENT SYSTEM FOR BENCHMARK TEST WITH LARGE SCALE MODEL OF NUCLEAR REACTOR
Authors: Dmitriev S. M. , Khrobostov A. E. , Barinov A. A. , Glavny V. G. 
Published: July 2018

The last decades development of applied calculation methods of nuclear reactor thermal and hydraulic processes are marked by the rapid growth of the High Performance Computing (HPC), which contribute to the active introduction of Computational Fluid Dynamics (CFD). The use of such programs to justify technical and economic parameters and especially the safety of nuclear reactors requires comprehensive verification of mathematical models and CFD programs. The aim of the work was the development and adaptation of a measuring system having the characteristics necessary for its application in the verification test (experimental) facility. It’s main objective is to study the processes of coolant flow mixing with different physical properties (for example, the concentration of dissolved impurities) inside a large-scale reactor model. The basic method used for registration of the spatial concentration field in the mixing area is the method of spatial conductometry. In the course of the work, a measurement complex, including spatial conductometric sensors, a system of secondary converters and software, was created. Methods of calibration and normalization of measurement results are developed. Averaged concentration fields, nonstationary realizations of the measured local conductivity were obtained during the first experimental series, spectral and statistical analysis of the realizations were carried out.The acquired data are compared with pretest CFD-calculations performed in the ANSYS CFX program. A joint analysis of the obtained results made it possible to identify the main regularities of the process under study, and to demonstrate the capabilities of the designed measuring system to receive the experimental data of the «CFD-quality» required for verification.The carried out adaptation of spatial sensors allows to conduct a more extensive program of experimental tests, on the basis of which a databank and necessary generalizations will be created. The received information allows to answer a number of questions related to scaling up the results of CFD calculations at the fullscale parameters of pressurized nuclear reactors.
METROLOGICAL SUPPORT OF DOSIMETRY GAMMA-RAY WITH ENERGY TO 10 MEV FOR RADIATION PROTECTION DEVICES
Authors: Komar D. I. , Lukashevich R. V. , Guzov V. D. , Kutsen S. A. 
Published: July 2018

The field of high-energy gamma-ray for the calibration of radiation protection devices can be obtained by capturing thermal neutrons from titanium target (to 7 MeV) and nickel target (to 10 MeV). The aim of this work was to determine the metrological characteristics of capture gamma-ray fields from titanium target and nickel target obtained at the AT140 Neutron Calibration Facility to provide dosimetry up to 10 MeV.We have chosen energy intervals in which we can calibrate dosimetry devices taking into account the accompanying generation of gamma-ray neutrons by the fast neutron source 238PuBe, the capture radiation of collimator materials and capture radiation from targets.We measured air kerma rate with the aid of the reference AT5350 dosimeter with the ionization chamber TM32002. Using the Monte-Carlo simulation, we obtained the energy distribution of the air kerma rate for targets. We determined the geometric dimensions of the uniform field and the interval of operating distances of the facility.We investigated the metrological characteristics of capture gamma-ray fields from titanium target and nickel target obtained at the AT140 Neutron Calibration Facility for dosimetric radiation protection devices. We showed that in such fields it is possible to calibrate dosimetry devices in the extended energy range up to 10 MeV.
DETERMINATION OF THE THICKNESS OF THE COMPONENTS OF A DOUBLE-LAYER NICKEL-CHROMIUM COATING BY MAGNETIC PONDEROMOTIVE METHOD WITH UNILATERAL ACCESS TO THE CONTROLLED SURFACE
Authors: Gnutenko Y. V. , Rudnitsky V. A. 
Published: July 2018

The application of thick-layer nickel (up to 700 μm) and chromium (up to 200 μm) coatings has been widely used to give the combustion chamber of a liquid-propellant rocket engine the required operational properties. The main parameter that determines the ability of a coating to fulfill its function is its thickness and uniformity of its distribution. The main problem of current nondestructive methods for determining the thickness of coatings under consideration is that they can be used only at the stage of production of rocket engineering products, when there is an access to the product from the side of the inner wall of the combustion chamber before and after applying a chromium coating to the nickel sublayer. However, when an already finished product arrives at subsequent stages of assembly to another enterprise, there is often a need of incoming control of the thicknesses of coatings from nickel and chromium. In this case, it is not possible to apply existing control techniques to a finished product, or the use of these techniques leads to unacceptable errors in the results of measurements. The goal of the research was to develop a technique for nondestructive determination of the thickness of each component of the two-layer nickel-chromium coating by the magnetic ponderomotive method under conditions of unilateral access to the finished product from the side of the chromium coating.A new technique for nondestructive determination of the thicknesses of nickel and chromium coatings of the double-layer structure on a finished product without a priori data on the properties or thicknesses of these coatings or a product in general is proposed using a magnetic ponderomotive method.This newly developed technique is implemented in the thickness gauge TEP-XN1 of double-layer nickel- chromium coatings, which is successfully used by enterprises of the rocket and space industry of the Russian Federation.
ANALYSIS OF THE ELECTROPHYSICAL AND PHOTOELECTRIC PROPERTIES OF NANOCOMPOSITE POLYMERS BY THE MODIFIED KELVIN PROBE
Authors: Pantsialeyeu K. U. , Krautsevich A. U. , Rovba I. A. , Lysenko V. I. , Vorobey R. I. , Gusev O. K. , Zharin A. L. 
Published: July 2018

At present for analysis of the homogeneity of materials properties are becoming widely used various modifications of a scanning Kelvin probe. These methods allow mapping the spatial distribution of the electrostatic potential. Analysis of the electropotential profile is not sufficient to describe any specific physical parameters of the polymer nanocomposites. Therefore, we use an external energy impact, such as light. Purpose of paper is the modification of the Kelvin scanning probe and the conduct of experimental studies of the spatial distribution and response of the electrostatic potential of the actual polymer nanocomposites to the optical probing.Carried out the investigations on experimental Low density polyethylene composites. Carbon nanomaterials and nanoparticles of silicon dioxide or aluminum as fillers are used. As a result, maps of the spatial distribution of the electrostatic potential relative values and the surface photovoltage. Statistical analysis of the electrophysical and photoelectric properties homogeneity, depending on the component composition of the composites carried out. In addition, with reference to matrix polymers, the Kelvin scanning probe, in combination with the optical probing, made it possible to detect a piezoelectric effect. The latter, can used as a basis for the development of new methods for studying the mechanical properties of matrix polymers.
DEVICE FOR BINARY DATA TRANSMITTING AND RECEIVING OVER A FIBEROPTIC COMMUNICATION CHANNEL
Authors: Timofeev A. M. 
Published: July 2018

When transferring data over optical fiber communication channels, it is required to provide data security and the authenticity of their source. To limit the access to the data for a third party, there can be applied quantum-cryptographical systems which are supposed to transfer every data bit by means of low power optical signals containing radiation photons the number of which could be in the range from 10 to 1, however, are far from being perfect and suffer from shortcomings, the main of which being a large number of errors due to the depolarization effect of optical radiation. The aim of this work was, therefore, to create device for sending and receiving confidential data which could provide complete security of transferred data, inherent to quantum-cryptographical communication systems at the same time could have a low number of such errors.A device for quantum-cryptographic communication system with a photon counter applied as a receiving module has been proposed. The possibility to use silicon avalanche photodetectors operating in the photon counting mode for confidential information transmission systems and defining authenticity of the source of transmitted information has been shown.I develop modern optical fiber communication system incorporating avalanche photodetector photon counter as a receiving module, that allow to detect unauthorized access to information and violation of its integrity and speed up the exchange of information in comparison with well-known quantum-cryptographical communication systems.
THE INFLUENCE OF SOIL DENSITY AND THE CHARACTER OF RADIOACTIVE 134Cs And 137Cs POLLUTION’S DISTRIBUTION ON in situ MEASUREMENTS
Authors: Zhukouski A. I. , Anshakou O. M. , Nichyparchuk A. O. , Marozik P. M. , Kuten S. A. 
Published: July 2018

Periodic radiation monitoring of soils today is a priority task not only for Belarus, but also for Japan, suffered by Fukushima nuclear power plant accident. Use of portable and light spectrometers with ability to perform in situ measurements makes it possible to quickly estimate specific activity of measured radionuclides with required accuracy in particular soil site. Basic information of a gamma radiation source (radionuclides content, effective radius of measurement area and thickness of contaminated layer) can be obtained directly during measurement. The purpose of this research is to test the feasibility of using algorithms for determination of specific activity and thickness of contaminated layer under conditions of soil measurement with variable density parameters and radiocesium distribution in soil.Monte-Carlo simulating allowed to estimate the degree of deviation of the shape of simulated spectra obtained with the use of Monte-Carlo soil model with uniformly distributed radionuclide in it, and for the case when the radionuclide distribution by soil profile can be described by an exponential function. For these cases of natural distribution of radiocesium, the pulse-amplitude spectrum is formed by an effective thickness of the contaminated site, which contains more than 90 % of radionuclides.The developed Monte-Carlo model of a probe and contaminated soil site allows to estimate the effect of the variability of soil density on the total count rate of the pulse-amplitude spectrum. As a result of theoretical estimations, the relationship between the effective radius of contaminated site is determined as a function of soil density.Analysis of the influence of radial zones of the cylindrical gamma source on in situ gamma-spectrometer showed that the main contribution to the total count rate of the pulse-amplitude spectrum is made by the radial zone with radius of up to 40 cm from the center of the probe, regardless of the thickness of the contaminated layer in geometry «Probe is located on the soil surface». A small site facilitates the selection of measurement area of land with a sufficiently flat surface, which is desirable during surveying the territories, especially with complex terrain.
CALCULATION OF STATIC PARAMETERS OF SILICON DIODE CONTAINING δ-LAYER OF TRIPLE-CHARGED POINT DEFECTS IN SYMMETRIC p–n-JUNCTION
Authors: Poklonski N. A. , Kovalev A. I. , Gorbachuk N. I. , Shpakovski S. V. 
Published: July 2018

The study of semiconductor materials and devices containing a narrow layer of impurity atoms and/or intrinsic point defects of the crystal lattice is of fundamental and practical interest. The aim of the study is to calculate the electric parameters of a symmetric silicon diode, in the flat p–n-junction of which a δ-layer of point triple-charged t-defects is formed. Such a diode is called p–t–n-diode, similarly to p–i–n-diode.Each t-defect can be in one of the three charge states (−1, 0, and +1; in the units of the elementary charge). It is assumed that at room temperature all hydrogen-like acceptors in p-region and hydrogen-like donors in n-region are ionized. It was assumed that the cross-section for v-band hole capture on t-defects is greater than the cross-section for c-band electron capture on t-defects.The system of stationary nonlinear differential equations, which describe in the drift-diffusion approximation a migration of electrons and holes in semiconductors, is solved numerically. The static capacityvoltage and current-voltage characteristics of the silicon diode with nondegenerate regions of pand n-type of electrical conductivity are calculated for forward and reverse electric bias voltage.It is shown by calculation that in the p–t–n-diode containing the δ-layer of t-defects, at the forward bias a region of current density stabilization occurs. At the reverse bias the current density in such a diode is much greater than the one in a p–n-diode without t-defects. With the reverse bias the capacitance of the p–t–n-diode, in contrast to the p–n-diode, increases at first and then decreases.
ANALYTICAL SYNTHESIS OF FORCED PULSE ELECTRONIC DRIVE CONTROL OF A TRACKING SYSTEM
Authors: Abufanas A. S. , Lobaty A. A. , Yacina Y. F. 
Published: July 2018

The problem of analytical synthesis of a control signal by a linear dynamical system is considered. As an optimization criterion, it is proposed to consider the transition time of the system from the initial state to a given final state. This type of control is called forced, providing the maximum system speed. The principle of solving this problem is considered on the basis of application of uncertain Lagrange multipliers and the Pontryagin maximum principle. Expressions are obtained for the matrix of transitions of the system and the control signal in a vector form.As an example, the electric drive described by the widespread second-order mathematical model is considered to evaluate the efficiency of the proposed method. Qualitative illustrations of the operability of the proposed approach, obtained by modeling in the Mathcad environment, and quantitative characteristics of the change in the input and output signals of the hypothetical control system are presented. It is shown that the use of forced control does not lead to the output of variables characterizing the state of the system, beyond the limits of admissible values.The use of forced control makes it possible to synthesize the control law in the form of a sequence of rectangular pulses of constant amplitude determined by the power source, variable duty cycle and polarity. This approach can be used for the control of DC-type DC motors used in various tracking systems used on unmanned aerial vehicles. Key words: forced control, target function, electric drive, pulse train. The use of forced control makes it possible to synthesize the control law in the form of a sequence of rectangular pulses of constant amplitude determined by the power source, variable duty cycle and polarity. This approach can be used for the control of DC-type DC motors used in various tracking systems used on unmanned aerial vehicles.
ONLINE-SERVICES AND INFORMATION TECHNOLOGIES IN DISTANCE LEARNING
Authors: Vishniakou U. A. , Kovalev A. P. 
Published: July 2018

The article deals with the analysis of distance learning (DL) methods, approaches, technologies, tools, the use as known online services so and developing the new ones. The terminology in area of DL is discussed and differences between correspondence course and DL are done. The development tendencies of distance learning are analyzed. Their technical and organization components are done. The course programs for DL are realizing by software which functions are shown. The typical lines of DL, their advances and lacks are conceded. As DL advances are self activity, individuality, independence and so on. As DL lacks are insufficiently individual, psychological, practical aspects, writing forms of DL and so on.Technologies and organization of DL including IT are discussed. The tutor activity is divided on two stages: decision of methodological, organizational problems and realization of distance courses. The various kind of online services in DL such as chats, web, TV, video conferences multimedia, robot learning, web-services are shown. Such IT for DL as CD, net, TV, satellite, cloud are discussed.The models of integration decisions for DL development such as Remote Procedure Calls (RPS), Enterprise Application Integration (EAL), Web-Services (WS), Enterprise Service Bus (ESB) are proposed. The content of e-learning online services including intellectual technologies and cloud computing are done. As new one integration method for DL is Semantic Web and Web-service (SWWS) with knowledge representation support on ontology base and knowledge processing on agents support are representation.
Plant Species Diversity of Naturalized Roughs as Affected by Conversion Strategies
Authors: Pornaro Cristina , Macolino Stefano , De Luca Alessandro , Sallenave Rossana , Leinauer Bernhard 
Published: July 2018

Core Ideas
Natural rough areas on a golf course contained 131 plant species.
The botanical composition of the naturalized areas is dominated by only a few species.
Cultural practices can improve species richness and botanical composition.
The efficacy of cultural practices in naturalized roughs depends on the dominant species.
A single cut can improve biodiversity, but can not reduce dominant species.
Golf courses can be characterized as plant communities with a simplified botanical composition. Improving roughs to achieve more naturalized areas can help to enhance the botanical biodiversity on golf courses. A 3‐yr study was conducted in a Mediterranean climate zone with the objectives of investigating the botanical composition of naturalized roughs by analyzing species richness and effective species number, and assessing the effectiveness of different cultural practices to increase biodiversity. Two sites dominated by either Elytrigia repens (L.) Nevski (Site 1) or by Festuca rubra L. (Site 2) were selected for the study. Three management practices were randomly assigned to plots within each site in May 2013: (i) mowing followed by biomass removal and verticutting, and subsequent supply of hay to provide seeds of local species; (ii) mowing followed by biomass removal and verticutting; and (iii) areas left unmowed (control). Cultural practices had a significant effect on biodiversity in the short‐term. The number of plant species at Site 1 was higher in plots receiving Management Practices A and B, and at Site 2 in plots receiving Management Practice A. In contrast, management practice had no effect on the percentages of dominant species. The principal component analysis (PCA) indicated a shift in botanical composition in plots receiving treatments A and B in the second year, while in the last year of the study, the botanical composition of all plots returned to its original state. A single cut in spring was not sufficient to counteract the dominance of highly competitive species.
Summary of Advances in the Heat‐Pulse Technique: Improvements in Measuring Soil Thermal Properties
Authors: Wen Minmin , Liu Gang , Horton Robert , Lu Yili , Ren Tusheng 
Published: July 2018

Core Ideas
The dual probe heat‐pulse (DPHP) method is used to measure soil thermal properties.
Special care is needed to obtain accurate DPHP measurements in field soil.
A review of theory, instrumentation and procedures needed is presented for DPHP.
This essay provides a summary of “Advances in the Heat‐Pulse Technique: Improvements in Measuring Soil Thermal Properties” recently appearing in Methods of Soil Analysis. Series.
Freely Accessible Chemical Database Resources of Compounds for In Silico Drug Discovery
Authors: Yang JingFang , Wang Di , Jia Chenyang , Wang Mengyao , Hao GeFei , Yang GuangFu 
Published: July 2018

Background:
In silico drug discovery has been proved to be a solidly established
key component in early drug discovery. However, this task is hampered by the limitation of
quantity and quality of compound databases for screening. In order to overcome these obstacles,
freely accessible database resources of compounds have bloomed in recent years. Nevertheless,
how to choose appropriate tools to treat these freely accessible databases is crucial. To
the best of our knowledge, this is the first systematic review on this issue.

Objective:
The existed advantages and drawbacks of chemical databases were analyzed and
summarized based on the collected six categories of freely accessible chemical databases from
literature in this review.

Results:
Suggestions on how and in which conditions the usage of these databases could be
reasonable were provided. Tools and procedures for building 3D structure chemical libraries
were also introduced.

Conclusion:
In this review, we described the freely accessible chemical database resources
for in silico drug discovery. In particular, the chemical information for building chemical database
appears as attractive resources for drug design to alleviate experimental pressure.