KPI Science News最新文献

{"title":"METHOD OF QUALIFICATION IN THE CONDITIONS OF TWO-PHASE MODES OF PASSIVE SAFETY SYSTEMS OF NUCLEAR POWER PLANTS","authors":"V. Filatov","doi":"10.20535/kpisn.2022.1-2.270364","DOIUrl":"https://doi.org/10.20535/kpisn.2022.1-2.270364","url":null,"abstract":"","PeriodicalId":33112,"journal":{"name":"KPI Science News","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41926245","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":"DESIGNS OF HEAT EXCHANGER DEVICES ON TWO-PHASE HEAT TRANSFER ELEMENTS FOR AIR HEAT DISPOSAL IN VENTILATION SYSTEMS: OVERVIEW","authors":"Yevgeny Alekseik","doi":"10.20535/kpisn.2022.1-2.264595","DOIUrl":"https://doi.org/10.20535/kpisn.2022.1-2.264595","url":null,"abstract":"Background. Heat exchangers-utilizers for recovery of ventilation air heat are widely used for increasing of buildings energy efficiency. Two-phase elements, such as: thermosyphons, heat pipes and pulsating heat pipes are applied to these heat exchangers for increasing of efficiency of heat transfer between hot and cold air. But such heat exchangers should have high temperature efficiency, enthalpy efficiency and energy efficiency at low aerodynamic drag. Moreover, working conditions of ventilation systems, such as: relatively low working temperatures and low temperature difference between hot and cold air, make it difficult to choose heat carriers for two-phase elements. Thus, it is necessary to solve a number of complex problems for designing of effective heat exchangers-utilizers based on two-phase elements. \u0000Objective. To find out unresolved and understudied issues of designing of heat exchangers-utilizers based on two-phase elements for ventilation systems. \u0000Methods. Analysis of described in literature designs, their characteristics and results of investigations. \u0000Results. General features of two-phase elements based heat exchangers-utilizers designs and a number of issues which need further investigation were detected as a result of literature sources analysis. \u0000Conclusions. Heat exchangers based on two-phase heat transfer elements have wide perspective of applying and provide full heat efficiency up to 85%. But there is a number of unsolved issues connected with: optimization of two-phase elements and heat exchangers design, ribbing optimization, investigation of heat transfer intensity and heat transfer coefficients, investigation of aerodynamic drag, condensate rejecting.","PeriodicalId":33112,"journal":{"name":"KPI Science News","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47178662","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":"CORROSION RESISTANCE OF GALVANIC NICKEL DEPOSITS AND ELECTROCHEMICAL ACTIVITY OF THEIR CORROSION PRODUCTS","authors":"Dmytro Uschapovskyi, O. Linyucheva, G. Vasiliev, Oleksander Liniuchev, A. Kushmyruk, R. Redko, Gleb Pidvashetsky, Taras Kurochenko","doi":"10.20535/kpisn.2022.1-2.253045","DOIUrl":"https://doi.org/10.20535/kpisn.2022.1-2.253045","url":null,"abstract":"D.Yu. Ushchapovskyi, A.I. Kushmyruk, G.S. Vasiliev, O.V. Linyucheva, R.M. Redko, O.G. Linyuchev, G.Yu. Pidvashetsky, T.A. Kurochenko\u0000CORROSION RESISTANCE OF GALVANIC NICKEL DEPOSITS AND ELECTROCHEMICAL ACTIVITY OF THEIR CORROSION PRODUCTS\u0000Background. Bright galvanic nickel coatings, with high sulphur content, are less corrosion resistant than matte. Bright nickel coatings are particularly susceptible to corrosion damage in conditions that simulate tropical humid climates and are characterized by the presence of acetic acid vapours.\u0000Objective. The purpose of the paper is to investigate: corrosion resistance of galvanic nickel deposits in concentrated acetic acid and its vapours, electrochemical activity of sulphide-containing corrosion products of bright nickel coatings.\u0000Methods. Potentiodynamic and cyclic volt-amperometry have been used to study the electrochemical activity of galvanic nickel deposits and their corrosion products. The corrosion rate of galvanic nickel deposits has been determined by gravimetric method. Investigation of surface morphology and composition of galvanic deposits were performed using scanning electron microscopy and X-ray fluorescence analysis.\u0000Results.The increased electrochemical activity of sulphide corrosion products of bright nickel coatings is evidenced by an order of magnitude higher cathodic current densities of CVA curves obtained in acetate buffer solutions, in comparison with bright and matte nickel galvanic deposits. It has been shown that at the deposition of sulphide corrosion products of bright nickel coatings on matte nickel foil the corrosion rate of last one increase at the exposition in concentrated acetic acid and its vapours.\u0000Conclusions. Significant intensifying effect of sulphur on the corrosion of galvanic nickel deposits in concentrated acetic acid and its vapours has been established. In particular, this can be explained by the decomposition of nickel sulphide (which incorporates in the coating) in acetic acid. Sulphur in the oxidation state (-2) interacts with passive oxide coatings to form an adsorbed monolayer, which leads to the transition of nickel to the active state. Further research will focus on a deeper study of the electrochemical properties of corrosion products of bright nickel coatings.\u0000Key words: nickel coatings, corrosion products, nickel sulphides, corrosion activity, catalyst.","PeriodicalId":33112,"journal":{"name":"KPI Science News","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47062281","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":"USE OF MODELS OF THE STRUCTURE OF PARTING SURFACES IN STEEL WHEN PRODUCING PRODUCTS WITH A SPECIFIED LIFE CYCLE","authors":"M. Kuzin","doi":"10.20535/kpisn.2022.1-2.270358","DOIUrl":"https://doi.org/10.20535/kpisn.2022.1-2.270358","url":null,"abstract":"","PeriodicalId":33112,"journal":{"name":"KPI Science News","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67680210","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":"THERMOMETRIC MODEL OF DIODE TEMPERATURE SENSOR","authors":"P. Yaganov","doi":"10.20535/kpisn.2022.1-2.251016","DOIUrl":"https://doi.org/10.20535/kpisn.2022.1-2.251016","url":null,"abstract":"Pavlov L.M., Yahanov P.O. \u0000THERMOMETRIC MODEL OF DIODE TEMPERATURE SENSOR \u0000  \u0000Background.  Microelectronic technologies make it possible to create structures with high sensitivity to external influences. In semiconductor microelectronics, these are structures of the type of potential barrier at the p-n junction. Silicon diode sensors have high temperature sensitivity in a wide temperature range. Both physical and formal mathematical models of the thermometric characteristic of the diode sensor have been developed. The temperature measurement error of some of these methods was not acceptable for the control of many processes. It is relevant to conduct studies of the temperature properties of the p-n transition in a non-equilibrium state to formalize the new thermometric characteristic of the diode sensor. \u0000Objective. The purpose of the work is a model of thermometric characteristics of silicon diode sensors based on the results of measurements of volt-ampere characteristics in the temperature range. \u0000Methods. Analysis of methods of calibration of thermometric characteristic of diode sensors by volt-ampere characteristics was carried out, factors affecting temperature measurement accuracy were revealed, regression analysis method for formation of polynomial model of thermometric characteristic was substantiated. \u0000Results. As a result of studies of the volt-ampere characteristics of silicon diodes in the temperature range (248... 393) K, it was found that the error in measuring temperature by diode sensors is associated with the dependence of the non-ideality factor of the p-n transition on temperature. The accuracy of the thermometric characteristic is estimated, where this functional dependence is represented as an approximation polynomial. \u0000Conclusions.  An alternative model of thermometric characterization of diode temperature sensors by the second degree regression equation is presented. The arguments of the function are the current and voltage of the diode in the direct displacement mode. Current stability in the p-n junction circuit is not assumed. The temperature determination accuracy in the temperature range (248... 393) K is within ± (0.2... 0,256) K. \u0000Keywords: diode temperature sensors; volt-ampere characteristic; non-ideality factor; regression; thermometric characteristic model. \u0000 ","PeriodicalId":33112,"journal":{"name":"KPI Science News","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42664871","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":"SIMULATION OF DIFFUSION-DRIFF PROCESSES IN THE ELECTRON-HOLE PLASMA OF THE P-I-N-DIODES ACTIVE REGION UNDER THE CONDITIONS OF A MW PENETRATING IN THE PLASMA BY THE PERTURBATION THEORY METHODS","authors":"I. Moroz, A. Bomba","doi":"10.20535/kpisn.2022.1-2.268688","DOIUrl":"https://doi.org/10.20535/kpisn.2022.1-2.268688","url":null,"abstract":"Background. The problem of developing tools for mathematical modeling of the state of electron-hole plasma in the p-i-n structures active region under the influence of an additional factor - a powerful microwave electromagnetic field is considered. The task is important for specialists in the field of microwave electronics, since p-i-n structures are used, in particular, for switching powerful electromagnetic fields and as protective devices for the input paths of radio engineering systems. \u0000Objective. It consists in developing a methodology for modeling the electron-hole plasma concentration distribution in the p-i-n- diodes active region taking into account the effect on the dynamics of charge carriers of microwave radiation penetrating into the active region and developing asymptotic methods for solving the corresponding singularly perturbed nonlinear problems. \u0000Methods. Achieving the goal is ensured by the use of boundary layer method, complex amplitudes method and classical analytic-numerical methods for solving boundary value problems for systems of ordinary differential equations. \u0000Results. A generalized mathematical model of the electron-hole plasma stationary state in the p-i-n diodes active region in the hydrodynamic approximation, which takes into account the effect of microwave radiation on processes in the plasma, is proposed. The model basis is a nonlinear singularly perturbed boundary value problem for the system of electron-hole currents continuity equations and the Poisson. The model boundary value problem is reduced to a recurrent sequence of linear boundary value problems. Solutions of the stated problem are found in the form of asymptotic series containing stationary and non-stationary components. A feature of the proposed mathematical model is that it reflects the effect of detecting an electromagnetic microwave TE-like wave on the charge carrier concentration distribution inhomogeneity in the p-i-n-diode active region. \u0000Conclusions. The methodology for modeling the electron-hole plasma stationary state in the p-i-n-diodes active region taking into account the effect on the charge carriers dynamics of microwave radiation penetrating into the active region has been developed. \u0000 ","PeriodicalId":33112,"journal":{"name":"KPI Science News","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45655933","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":"Automated design of zoom riflescope with extended parameters","authors":"V. Sokurenko","doi":"10.20535/kpisn.2022.1-2.252085","DOIUrl":"https://doi.org/10.20535/kpisn.2022.1-2.252085","url":null,"abstract":"Sokurenko V. M., Sokurenko O. M. \u0000AUTOMАТED DESIGN OF ZOOM RIFLESCOPE WITH EXTENDED PARAMETERS \u0000Background. Designing an arbitrary afocal zoom optical system is a complex and multidimensional problem. It cannot be solved analytically and requires the essential experience and efforts of the designer. \u0000Objective. The purpose of the paper is to present and verify by simulation the method and means to perform an automated design of complex multi-lens afocal zoom optical systems having variable parameters and characteristics. \u0000Methods. Using the developed specialized software with implemented modification of the adaptive Cauchy differential evolution algorithm for the parametric synthesis of multi-component optical systems of zoom riflescopes with extended functional parameters. \u0000Results. The developed optical system of the riflescope provides the 5× magnification ratio and the angular field of view in the object space from 3.26° to 0.83°. It has a reticle located in the first focal plane, the entrance pupil diameter of 60 mm, the eye relief within the range 106...111 mm, and the maximum system length of 390 mm. The riflescope contains 13 lenses in 10 components. The performed simulations showed that the time interval required for direct automated design of the riflescope’s optical system is about 30 hours for the total number of unknown parameters (variables) equal to 91. The root-mean-square values ​​of the angular aberrations of axial beams in all (five) configurations of the synthesized zoom system do not exceed 1.25 arc minute in the whole spectral range. The algorithm helps to determine the prescription data of optical systems, taking into account the technical requirements and restrictions specified by the designer. \u0000Conclusions: Computer simulations of the development of the zoom riflescope with the magnification of 5-25×, the entrance pupil diameter of 60 mm, and the reticle located in the first focal plane have confirmed the effectiveness of the proposed algorithm to design automatically complex multi-lens optical systems with variable parameters. The obtained results proved the high image quality of the generated 13-lens riflescope with the long eye relief. The implemented modification of the adaptive Cauchy differential evolution method can be considered a powerful tool that helps to automate the parametric synthesis of multicomponent optical systems of zoom riflescopes, taking into account the requirements set by the designer. Future research should test the feasibility of automated design of other riflescopes containing more lenses and providing extreme performances.","PeriodicalId":33112,"journal":{"name":"KPI Science News","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48479816","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":"FINITE APPROXIMATION OF NONCOOPERATIVE 2-PERSON GAMES PLAYED IN STAIRCASE-FUNCTION CONTINUOUS SPACES","authors":"V. Romanuke","doi":"10.20535/kpisn.2022.1-2.270281","DOIUrl":"https://doi.org/10.20535/kpisn.2022.1-2.270281","url":null,"abstract":"V. Romanuke \u0000Finite approximation of noncooperative 2-person games played in staircase-function continuous spaces \u0000Background. There is a known method of approximating continuous noncooperative 2-person games, wherein an approximate solution (an equilibrium situation) is considered acceptable if it changes minimally by changing the sampling step minimally. However, the method cannot be applied straightforwardly to a 2-person game played with staircase-function strategies. Besides, the independence of the player’s sampling step selection should be taken into account. \u0000Objective. The objective is to develop a method of finite approximation of 2-person games played in staircase-function continuous spaces by taking into account that the players are likely to independently sample their pure strategy sets. \u0000Methods. To achieve the said objective, a 2-person game, in which the players’ strategies are staircase functions of time, is formalized. In such a game, the set of the player’s pure strategies is a continuum of staircase functions of time, and the time is thought of as it is discrete. The conditions of sampling the set of possible values of the player’s pure strategy are stated so that the game becomes defined on a product of staircase-function finite spaces. In general, the sampling step is different at each player and the distribution of the sampled points (function-strategy values) is non-uniform. \u0000Results. A method of finite approximation of 2-person games played in staircase-function continuous spaces is presented. The method consists in irregularly sampling the player’s pure strategy value set, finding the best equilibria in “smaller” bimatrix games, each defined on a subinterval where the pure strategy value is constant, and stacking the equilibrium situations if they are consistent. The stack of the “smaller” bimatrix game equilibria is an approximate equilibrium in the initial staircase game. The (weak) consistency of the approximate equilibrium is studied by how much the payoff and equilibrium situation change as the sampling density minimally increases by the three ways of the sampling increment: only the first player’s increment, only the second player’s increment, both the players’ increment. The consistency is decomposed into the payoff, equilibrium strategy support cardinality, equilibrium strategy sampling density, and support probability consistency. It is practically reasonable to consider a relaxed payoff consistency. \u0000Conclusions. The suggested method of finite approximation of staircase 2-person games consists in the independent samplings, solving “smaller” bimatrix games in a reasonable time span, and stacking their solutions if they are consistent. The finite approximation is regarded appropriate if at least the respective approximate (stacked) equilibrium is -payoff consistent. \u0000Keywords: game theory; payoff functional; staircase-function strategy; bimatrix game; irregular sampling; approximate equilibrium consistency.","PeriodicalId":33112,"journal":{"name":"KPI Science News","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42290607","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":"Use of implementations of arbitrary bitness permutations for cryptographic transformations","authors":"Maxim Bondarchuk, O. Teslenko","doi":"10.20535/kpisn.2022.1-2.263225","DOIUrl":"https://doi.org/10.20535/kpisn.2022.1-2.263225","url":null,"abstract":"Background. Cryptographic transformations have always aroused the interest of the educated part of humanity and are an integral part of modern communications. A lot of different cryptographic algorithms exist for different tasks and requirements. Permutation functions are useful for cases where transformation speed is more critical than theoretical secrecy. Hardware implementation of such substitutions is quite simple. \u0000Objective. Investigate the model and combinational circuits for hardware implementation. Investigate algorithms for permutation functions software implementation. Investigate attack algorithms and cracking of permutation functions for cryptanalysis. \u0000Methods. The paper reviews algorithms of cryptographic transformations and their cryptanalysis for bijective permutations implemented by means of regular combinational structures of linear complexity. The proposed algorithms provide the rate of processing up to gigabits per second. The paper clarifies the algorithm of formation of elements of regular structures of permutations, specifies volumes of public and private data, reviews data formats, methods of their transfer and hardware implementation of one of the methods. The paper reviews attack types and permutation regular structure schemes cracking algorithms with experimental calculation of necessary operations quantity. The software implementation of the proposed algorithms for results calculation was developed. \u0000Results. Numerical results of the number of keys, the amount of memory required for hardware implementation and the number of required operations for cryptanalysis were obtained. \u0000Conclusions. The results show that the proposed algorithms for cryptographic transformations have a sufficient level of protection with a high-speed encryption and decryption.","PeriodicalId":33112,"journal":{"name":"KPI Science News","volume":"61 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41269572","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":"SOFTWARE METHODS ANALYSIS OF OPTIMIZING THE LOCAL STATE OF DATA WEB APPLICATIONS MANAGEMENT","authors":"Lyubov Оleshchenko","doi":"10.20535/kpisn.2022.1-2.260552","DOIUrl":"https://doi.org/10.20535/kpisn.2022.1-2.260552","url":null,"abstract":"Background. The use of various libraries often leads to a decrease in the speed of the web application and the complexity of the execution of the program code. The object of this study is the process of storing and managing the data of the client part of the web application, the subject of the research is the software methods of managing the local state of the data of the web application. \u0000Objective. The goal of the article is the reduction in the data processing time of web applications relative to existing software methods. \u0000Methods. The main idea of ​​the proposed method is to use an atomic approach to the state of the web application data. Having an arbitrary entity, in the general state of the web application, a state fragment is created that is responsible only for this entity. Such a fragment is independent of other state fragments and can only work with the encapsulated entity. Using encapsulation, the configuration of an entity is passed to the React Context API as an object containing data and functions that modify it. \u0000Results. The developed framework method was compared with popular state management libraries Redux, MobXState-Tree and Recoil. Comparing each of the test scenarios in a percentage ratio, an average decrease in program execution time by 17% was obtained. \u0000Conclusions. The Redux, MobXState-Tree, and Recoil libraries were selected for the research of existing software methods. The analysis of methods was performed using the SonarQube utility. To evaluate the results of the software methods, the Google Chrome browser utility DevTools was used. The proposed optimized software method allows to reduce the data processing time and optimize the state management of web applications. \u0000  Keywords: web application, optimization, local state of data, Redux, MobXState-Tree, Recoil.","PeriodicalId":33112,"journal":{"name":"KPI Science News","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44921644","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}