Vital and health statistics. Ser. 4, Documents and committee reports最新文献

{"title":"Positive Deviation of the Hall-Petch Relationship for Aluminum Condensates Alloyed with Iron","authors":"E. Lutsenko, A. Zubkov, Maria Zhadko, E. Zozulya","doi":"10.26565/2312-4334-2021-4-17","DOIUrl":"https://doi.org/10.26565/2312-4334-2021-4-17","url":null,"abstract":"The structure and strength properties of vacuum aluminum condensates alloyed with iron in the concentration range of 0.1 – 3.2 at. % is studied in the paper. It is shown that up to a concentration of about 2 at. % Fe, the grain size decreases, the strength properties increase and the lattice parameter values of these objects remain unchanged. It is found that at an iron concentration of up to ~ 2 at. % its atoms are concentrated in the grain boundaries of the aluminum matrix metal in the form of grain boundary segregation. At high concentrations, the structure of condensates is a supersaturated solution of iron in the FCC crystal lattice of aluminum. Highly dispersed Al13Fe4 intermetallic compounds are present at the grain boundaries and within the volume of grains. It has been found that the Hall-Petch coefficient for one-component aluminum condensates is 0.04 MPa·m1/2, which is typical for this metal. For Al-Fe condensates, a positive deviation from the Hall-Petch dependence is observed and the coefficient k increases to 0.4 MPa·m1/2 for a structure with grain boundary segregations and to 0.14 MPa·m1/2 for condensates containing intermetallic compounds. The obtained experimental results are explained by the different structural-phase state of the grain boundaries of the aluminum matrix.","PeriodicalId":76806,"journal":{"name":"Vital and health statistics. Ser. 4, Documents and committee reports","volume":"64 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85025485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"GEANT4 Modeling of the Bremsstrahlung Converter Optimal Thickness for Studying the Radiation Damage Processes in Organic Dyes Solutions","authors":"T. Malykhina, V. Kovtun, V. Kasilov, S. Gokov","doi":"10.26565/2312-4334-2021-4-10","DOIUrl":"https://doi.org/10.26565/2312-4334-2021-4-10","url":null,"abstract":"The study of the processes occurring in a matter when ionizing radiation passes through is important for solving various problems. Examples of such problems are applied and fundamental problems in the field of radiation physics, chemistry, biology, medicine and dosimetry. This work is dedicated to computer modeling of the parameters of a tungsten converter for studying the processes of radiation damage during the interaction of ionizing radiation with solutions of organic dyes. Simulation was carried out in order to determine the optimal thickness of the converter under predetermined experimental conditions. Experimental conditions include: energies and type of primary particles, radiation intensity, target dimensions, relative position of the radiation source and target. Experimental studies of the processes of radiation damage occurring in solutions of organic dyes are planned to be carried out using the linear electron accelerator \"LINAC-300\" of the National Scientific Center \"Kharkov Institute of Physics and Technology\". Electrons with 15 MeV energy are chosen as primary particles. The interaction of electrons with the irradiated target substances is planned to be studied in the first series of experiments. Investigations of the interaction of gamma quanta with the target matter will be carried out in the second series of experiments. The tungsten converter is used to generate a flux of bremsstrahlung gamma rays. One modeling problem is determination of the converter thickness at which the flux of bremsstrahlung gamma will be maximal in front of the target. At the same time, the flow of electrons and positrons in front of the target should be as low as possible. Another important task of the work is to identify the possibility of determining the relative amount of radiation damage in the target material by the Geant4-modeling method. Radiation damage of the target substance can occur due to the effect of bremsstrahlung, as well as electrons and positrons. Computational experiments were carried out for various values of the converter thickness – from 0 mm (no converter) to 8 mm with a step of 1 mm. A detailed analysis of the obtained data has been performed. As a result of the data analysis, the optimal value of the tungsten converter thickness was obtained. The bremsstrahlung flux in front of the target is maximum at a converter thickness of 2 mm. But at the same time, the flux of electrons and positrons crossing the boundaries of the target does not significantly affect the target. The computational experiment was carried out by the Monte Carlo method. A computer program in C++ that uses the Geant4 toolkit was developed to perform calculations. The developed program operates in a multithreaded mode. The multithreaded mode is necessary to reduce the computation time when using a large number of primary electrons. The G4EmStandardPhysics_option3 model of the PhysicsList was used in the calculations. The calculations necessary for solving the p","PeriodicalId":76806,"journal":{"name":"Vital and health statistics. Ser. 4, Documents and committee reports","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81578280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of the Structural Composition of Fe-Mn-Si-Ti-Al-N-C Alloys and the Solubility of Elements in α-Iron","authors":"N. Filonenko, O. Babachenko, H. Kononenko, A. Baskevich","doi":"10.26565/2312-4334-2021-4-14","DOIUrl":"https://doi.org/10.26565/2312-4334-2021-4-14","url":null,"abstract":"The study of the structural components of Fe-Mn-Si-Ti-Al-N-C with the carbon content of 0.50-0.60% (wt.), Silicon 0.80-0.90% (wt.), Manganese 0.90-0.95% ( wt. ), Aluminum - 0.20-0.30% (wt.), Titanium - 0.02-0.03% (wt.), Nitrogen - 0.015-0.02% (wt.), the rest - iron. Microstructural, micro-X-ray spectral and X-ray phase analyzes were used to determine the structural state of the alloys. It is shown that after crystallization and a number of phase transformations the structure of the alloy was presenteda - iron alloyed with cementite, oxides, nitrides and carbonitrides. Using the quasi-chemical method, the free energy dependence of the solid solution of α-iron alloyed with silicon, manganese and titanium was obtained. In α-iron, it can dissolve up to 0.016% (at.) Carbon, manganese up to 1.3% (at.), Silicon - 1.0% (at.), and titanium up to 0.5% (at.), which is consistent with experimental results.","PeriodicalId":76806,"journal":{"name":"Vital and health statistics. Ser. 4, Documents and committee reports","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80989924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing Si Solar Cells Efficiency by Adding SiO2 / TiO2 Thin Films Using Transfer Matrix Method","authors":"Wedad Ahmed Abdullah Garhoom, Z. Shadidi","doi":"10.26565/2312-4334-2021-4-22","DOIUrl":"https://doi.org/10.26565/2312-4334-2021-4-22","url":null,"abstract":"Thin film silicon solar cells are nowadays the best choice to get electricity due to their low cost compared to the crystalline solar cells. However, thin film silicon solar cells have weak absorption of incident light. To deal with such a weakness and get better efficiency of these cells, an efficient back reflector composed of multilayer thin films (Silver, Silicon dioxide (SiO2) and Titanium dioxide (TiO2)) will be used. The transmitted light from the first silicon layer will be reflected by the next layer, and the reflected light will go back to the first silicon layer. By this way, the absorbance of the silicon solar cell can be increased by an increase in the probability of the light reflection from the SiO2, TiO2 and Ag. The transfer matrix method (TMM) by Matlab program will be used to analyze the results of the reflectance, transmittance and absorbance of the thin film layer and these results can prove the efficiency of the cells by using MATLAB codes.","PeriodicalId":76806,"journal":{"name":"Vital and health statistics. Ser. 4, Documents and committee reports","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89495118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of Particular Solutions of the Burgers Equation to Describe the Evolution of Shock Waves of Density of Elementary Steps","authors":"O. Andrieieva, V. Tkachenko, O. Kulyk, O. Podshyvalova, V. Gnatyuk, T. Aoki","doi":"10.26565/2312-4334-2021-4-06","DOIUrl":"https://doi.org/10.26565/2312-4334-2021-4-06","url":null,"abstract":"Particular solutions of the Burgers equations (BE) with zero boundary conditions are investigated in an analytical form. For values of the shape parameter greater than 1, but approximately equal to 1, the amplitude of the initial periodic perturbations depends nonmonotonically on the spatial coordinate, i.e. the initial perturbation can be considered as a shock wave. Particular BE solutions with zero boundary conditions describe a time decrease of the amplitude of initial nonmonotonic perturbations, which indicates the decay of the initial shock wave. At large values of the shape parameter , the amplitude of the initial periodic perturbations depends harmoniously on the spatial coordinate. It is shown that over time, the amplitude and the spatial derivative of the profile of such a perturbation decrease and tend to zero. Emphasis was put on the fact that particular BE solutions can be used to control numerical calculations related to the BE-based description of shock waves in the region of large spatial gradients, that is, under conditions of a manifold increase in spatial derivatives. These solutions are employed to describe the profile of a one-dimensional train of elementary steps with an orientation near <100>, formed during the growth of a NaCl single crystal from the vapor phase at the base of a macroscopic cleavage step. It is shown that the distribution of the step concentration with distance from the initial position of the macrostep adequately reflects the shock wave profile at the decay stage. The dimensionless parameters of the wave are determined, on the basis of which the estimates of the characteristic time of the shock wave decay are made.","PeriodicalId":76806,"journal":{"name":"Vital and health statistics. Ser. 4, Documents and committee reports","volume":"56 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76209260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrical and Photoelectric Properties of Organic-Inorganic Heterojunctions PEDOT:PSS/n-CdTe","authors":"H. Parkhomenko, M. Solovan, A. Mostovyi, I. Orletskyi, V. Brus","doi":"10.26565/2312-4334-2021-4-04","DOIUrl":"https://doi.org/10.26565/2312-4334-2021-4-04","url":null,"abstract":"PEDOT: PSS thin films are widely used as transparent coatings in flexible semiconductor devices including solar cells. However, they are not widely used as transparent coatings in combination with crystal substrates. This work shows the possibility of using PEDOT:PSS thin films as a frontal transparent conducting layer in hybrid organic-inorganic Schottky type heterojunctions of the PEDOT:PSS/n‑CdTe, which were prepared by deposition of PEDOT:PSS thin films (using the spin-coating method) on crystalline cadmium telluride substrates. The current-voltage (in a wide temperature range) and capacitance-voltage (at room temperature) characteristics of heterojunctions were measurement and analyzed. It has been established that PEDOT:PSS/n-CdTe heterojunctions have good diode properties with a high rectification ratio RR≈105, a potential barrier height φ0 = 0.95 eV, and series Rs = 91 Ohm and shunt Rsh = 5.7 × 107 Ohm resistances. Analysis of the forward branches of the I–V characteristics of heterojunctions showed that the dominant charge transfer mechanisms are determined by the processes of radiative recombination at low biases (3kT/e <V <0.3 V) and tunneling through a thin depleted layer at high biases (0.3 V <V <0.6 V). Capacity-voltage characteristics are plotted in the Mott-Schottky coordinate, taking into account the influence of series resistance, measured at a frequency of 1 MHz. Used the C-V characteristic was determined the value of the built-in potential Vc = 1.32 V (it correlates well with the cutoff voltage determined from the current-voltage characteristics) and the concentration of uncompensated donors in the n-CdTe substrate ND-NA = 8.79 × 1014 cm-3. Although the photoelectric parameters of unoptimized PEDOT:PSS/n-CdTe heterojunctions are low, their photodiode characteristics (Detectivity D*> 1013 Jones) are very promising for further detailed analysis and improvement. The proposed concept of a hybrid organic-inorganic heterojunction also has potential for use in inexpensive γ- and X-ray detectors.","PeriodicalId":76806,"journal":{"name":"Vital and health statistics. Ser. 4, Documents and committee reports","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84258050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Concept of Neutron Source Creation for Nuclear Medicine on the Basis of Linear Electron Accelerator","authors":"V.Y. Kasilov, S. Gokov, S. Kalenik, S. Kochetov, Leonid Saliy, V. Tsyats'ko, Evgen Tsyats'ko, O. Shopen","doi":"10.26565/2312-4334-2021-4-21","DOIUrl":"https://doi.org/10.26565/2312-4334-2021-4-21","url":null,"abstract":"We review the current status of the development of sources of epithermal neutrons sources based on reactors and accelerators for boron neutron capture therapy (BNCT), a promising method of malignant tumor treatment. The scheme is proposed of the source prototype for the production of thermal and epithermal neutrons using the delayed neutrons generated with help of linear electron accelerator at the target containing the fissile material. The results of an experiment are presented in which the half-life curves of radioactive nuclei formed during fission and emitting delayed neutrons are measured. It is shown that an activated target containing fissile material is a compact small-sized source of delayed neutrons. It can be delivered to the shaper, where, using a moderator, an absorber, and a collimator, neutrons of thermal or epithermal energies are formed over a certain period of time, after which this target is sent to the activator, and another target comes in its place. Thus, a pulsed neutron flux is formed. Such a neutron beam can be used in nuclear medicine, in particular, in neutron capture therapy in the treatment of cancer. An important task in the implementation of neutron capture therapy, when irradiating patients, is to control both the intensity and the energy spectrum of the neutron flux. To solve this problem, an earlier developed activation-type neutron ball spectrometer can be used, which will allow optimization of various parameters of the shaper, collimator and filters in order to obtain the most powerful neutron fluxes.","PeriodicalId":76806,"journal":{"name":"Vital and health statistics. Ser. 4, Documents and committee reports","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76299567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the Impact Parameter Dependence of the Ionization Energy Loss of Fast Negatively Charged Particles in an Oriented Crystal","authors":"S. Trofymenko, I. Kyryllin, O. Shchus","doi":"10.26565/2312-4334-2021-4-07","DOIUrl":"https://doi.org/10.26565/2312-4334-2021-4-07","url":null,"abstract":"When a fast charged particle passes through matter, it loses some of its energy to the excitation and ionization of atoms. This energy loss is called ionization energy loss. In rather thin layers of matter, the value of such energy loss is stochastic. It is distributed in accordance with the law, which was first received by L.D. Landau. In amorphous substances, such a distribution (or spectrum), known as the Landau distribution, has a single maximum that corresponds to the most probable value of particle energy loss. When a particle moves in crystal in a planar channeling mode, the probability of close collisions of the particle with atoms decreases (for a positive particle charge) or increases (for a negative charge), which leads to a change in the most probable energy loss compared to an amorphous target. It has recently been shown that during planar channeling of negatively charged particles in a crystal, the distribution of ionization energy loss of the particles is much wider than in the amorphous target. In this case, this distribution can be two-humped, if we neglect the incoherent scattering of charged particles on the thermal oscillations of the crystal atoms and the electronic subsystem of the crystal. This paper explains the reason for this distribution of ionization energy loss of particles. The ionization energy loss distribution of high-energy negatively charged particles which move in the planar channeling mode in a silicon crystal are studied with the use of numerical simulation. The dependence of this distribution on the impact parameter of the particles with respect to atomic planes is considered. The dependence of the most probable ionization energy loss of particles on the impact parameter is found. It is shown that, for a large group of particles, the most probable ionization energy loss during planar channeling in a crystal is lower than in an amorphous target.","PeriodicalId":76806,"journal":{"name":"Vital and health statistics. Ser. 4, Documents and committee reports","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81246432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plasma Conversion of CO2 in DC Glow Discharge with Distributed Gas Injection and Pumping","authors":"V. Lisovskiy, S. Dudin, P. Platonov, V. Yegorenkov","doi":"10.26565/2312-4334-2021-4-20","DOIUrl":"https://doi.org/10.26565/2312-4334-2021-4-20","url":null,"abstract":"Accumulation of carbon dioxide in the Earth's atmosphere leads to an increase in the greenhouse effect and, as a consequence, to significant climate change. Thus, the demand to develop effective technologies of carbon dioxide conversion grows year to year. Additional reason for research in this direction is the intention of Mars exploration, since 96% of the Martian atmosphere is just carbon dioxide, which can be a source of oxygen, rocket fuel, and raw materials for further chemical utilization. In the present paper, the plasma conversion of carbon dioxide have been studied in the dc glow discharge at the gas pressure of 5 Torr in a chamber with distributed gas injection and evacuation from the same side for the case of narrow interelectrode gap. The conversion coefficient and the energy efficiency of the conversion were determined using mass spectrometry of the exhaust gas mixture in dependence on CO2 flow rate and the discharge current and voltage. Maximum conversion rate was up to 78% while the energy efficiency of the conversion was always less than 2%. It was found that the discharge at this pressure can operate in normal and abnormal modes and the transition between the modes corresponds just to the maximum value of the conversion coefficient for a given gas flow. It was shown that even in anomalous regime, when the cathode is completely covered by the discharge, the discharge contraction occurs in whole range of parameters studied. The anode glow and the plasma column outside the cathode layer occupy the central part of the discharge only that reduces the conversion efficiency. Optical emission spectra from the carbon dioxide plasma were measured in the range of 200-1000 nm, which allowed to make a conclusion that the Oxygen atom emission is mostly origins from the exited atoms appearing after dissociation rather than after electron impact excitation.","PeriodicalId":76806,"journal":{"name":"Vital and health statistics. Ser. 4, Documents and committee reports","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85432835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal-Vacuum Method for Obtaining Nanodispersed Zirconium Dioxide","authors":"V. Kutovyi, D. Malykhin, V. Virych, R. Vasilenko","doi":"10.26565/2312-4334-2021-4-09","DOIUrl":"https://doi.org/10.26565/2312-4334-2021-4-09","url":null,"abstract":"An energy-efficient thermal-vacuum method for continuous production of nanodispersed powder of amorphous zirconium dioxide from zirconium hydroxide has been developed. This approach is based on a principle of creating an aerodynamic flow with an initial powder-like material in the cavity of the heating element of a thermal-vacuum installation. In this way, short-term contacts of particles of zirconium hydroxide with the inner surface of the heating element made in the form of the winding helical are created. As a result, the crushing of the particles is carried out due to the high thermal stresses in the particles contacted. This process is aggravated by the presence of residual moisture in the original powdery material. Transformations of the zirconium hydroxide in the process of thermal-vacuum treatment have been investigated. Amorphous dioxide has been obtained. The study of structural composition of the material in the initial state and processed in a thermal-vacuum installation was carried out using X-ray analysis and scanning microscopy. Experimental data on the structural-phase composition of the original material and data on the closest structural prototypes of crystalline-impurity compounds are presented. They are also given data on the volume of crystal cells and estimates of the molar concentration of the components. A mass spectrometric assessment of the elemental composition of the obtained zirconium dioxide is given. Thermal-vacuum method allows toobtain highly dispersed zirconium dioxide in its amorphous state directly from zirconium hydroxide without using liquid media and, moreover, in a short time – within 15...20 s.","PeriodicalId":76806,"journal":{"name":"Vital and health statistics. Ser. 4, Documents and committee reports","volume":"71 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86383862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}