Modelling and Assessment of Risk of Failure Auxiliaries Supply System of Nuclear Power Plant from External Independent Sources / Bardyk Ie.I. - K. Наукові вісті НТУУ “КПІ”. – 2015. – N 2. – P.
Problematics. In the conditions of objectively existing aging of electric equipment, climatic conditions deterioration, hard work schedule of operation personnel at modern EES of NPS, there grows the problem of ensuring reliability and safety of functioning of the NPS in the emergencies in a power supply system. That requires carrying out the complex risk analysis of EES subsystems and NPS operation in the case of refusal of electrical equipment.
Research objective. Development of mathematical support and software for assessment of circuits reliability and refusal risk of NPS MV external power supply system under conditions of internal MV power supply loss for providing the mode of shut-down cooling and cold start of the block.
Implementing procedure. In the condition of essential incompleteness and uncertainty of statistical information on refusals of external network electric equipment, the hybrid fuzzy-stochastic models of certain electrical equipment failure for an assessment of refusal risk of NPP MV external power source method of electrical equipment failure function of distribution is attached. It is based on use of statistical data on refusals of main population of certain type and voltage class electric equipment as well as the expert estimates of refusal intensity of certain units of equipment.
Results of research. The hybrid fuzzy-stochastic models of refusals of the main power and switching equipment of power supply systems and own needs of the NPS and fuzzy-stochastic models of refusal risk assessment of MV external power supply system are developed. The probability assessment of no-failure operation and fuzzy ranging on reliability is carried out for four versions of power supply circuits of the NPS HV distributing device; the refusal risk assessment of the external power supply system from remote power plants and substations is executed.
Conclusions. In order to estimate schemes reliability and risk failure of electrical equipment and system of power supply MV from external supplies, fuzzy mathematical models were developed and failure risk estimation of four power supplies schemes for high-voltage NPS highways.
Keywords: Nuclear Power Plant; reliability; risk; failure; fuzzy sets; probability; electric power supply.
Systemic Approach to Forecasting / Bidyuk P.I., Trofymchuk O.M., Bidiuk O.P. - K. Наукові вісті НТУУ “КПІ”. – 2015. – N 2. – P.
Background. Further enhancement of forecasts quality for dynamics of financial and economic processes requires development of new techniques and approaches in the frames of modern concepts for constructing informational decision support systems (DSS).
Objective. The main purpose of the study is as follows: to consider system analysis principles that are suitable for solving the problem of short-term forecasting; to develop effective data processing system that implements the system analysis principles selected in the frames of DSS; to analyze possible types of uncertainties that are encountered in model constructing and forecasts estimating, and to propose the methods for their description and taking into consideration.
Methods. To develop DSS for forecasting financial and economic processes and estimation of financial risks the following system analysis principles were hired: hierarchical architecture, the possibilities for identification and processing possible uncertainties, alternatives computing, and tracking the computational procedures for all stages of data processing. The system developed provides possibilities for taking into consideration statistical and parametric uncertainties. The DSS proposed has a modular architecture that could be easily expanded with new functions like preliminary data processing, model parameters estimation, and procedures for computing forecasts and financial risks.
Results. The main result of the study is systemic methodology of mathematical modeling financial and economic processes, that has been implemented in the frames of the DSS proposed. High quality of final results is achieved thanks to appropriate tracking of all computations using several sets of statistical quality criteria. An example is given for mathematical modeling, estimation and forecasting of financial risk. The results of estimation show that the systemic approach proposed has good perspectives for its practical use.
Conclusions. Thus, we proposed a systemic approach to mathematical modeling and forecasting financial and economic processes as well as estimation of financial risk. The use of the approach provides possibilities for computing estimate forecasts of high quality using statistical data.
Keywords: uncertainties in modeling and forecasting; systematic approach; decision support system.
Primitive Programing Algebra of Computable Functions at Records / Zakharchenko T.L., Redko D.I., Redko I.V., Iaganov P.O. - K. Наукові вісті НТУУ “КПІ”. – 2015. – N 2. – P.
Background. The research is conducted in the context of compositional approach to programming. Problematic of the research is development of scientific foundations of programmer’s problems solution genesis. Its basis is concept of composition.
Objective. The objective of the research is general method development for function classes’ algebraic characteristics obtaining and application of the method for description of pragmatically important class of partially recursive functions on records.
Methods. Creations made in the paper are based on software analysis algebraic methods and compositional programming methodic. Problems of computable functions’ characteristics obtaining, problems of generative sets and bases finding, which are one of the most important questions in programmer’s problematic, are strictly stated and solved in the context of so called “program algebras”.
Results. In the paper method of mentioned problems solution was proposed in context of primitive program algebras (PPA) on different classes of computable functions. Received results are stated as sequence of original statements, lemmas, and theorems. They can be used for different classes of computable functions algebraic characteristics exploration in problems of programming languages semantics formalization.
Conclusions. Received results are foundations of adaptive programming environments development. Next steps in this direction will be connected with exploration of general concept of composition and development of related reduction methods of function exploration as environments of pragmatic depended programmer’s problems decomposition.
Keywords: fullness of calculable functions; fullness problem in PPA; complete system; pairs of natural numbers; pr-functions; pr-predicates.
Finish Polishing With Elbor Elastic Tape of Details of Antifriction Alloys Based on Aluminum for Printing Machines / Gavrish А.P., Roik Т.A., Zigulia S.M., Vitsuk Yu.Yu. - K. Наукові вісті НТУУ “КПІ”. – 2015. – N 2. – P.
Background. The technological process of the polish with elbor elastic tape on the base details of the rotation from new composite material on the base of utilized and regenerated grinding wastes production with aluminum АМ4,5Кд, АК12М2МгН, АК8МЗч and АК12ММгН + (9–12 %) MoS2 has been researched.
Objective. The influence on the parameters quality type elbor elastic tape, the characteristic of the cutting layer of the polish tape, grain micropowders and parameters of cutting on the detail surface was studied.
Methods. Surface treatment of printing machines parts made from wear-resistant aluminum composite finishing diamond grinding belts using ultrasound energy was used.
Results. New method of elbor polishing parts of aluminum-based composites and a new polishing tape based on polyethylene terephthalate for surface treatment of composite friction materials parts was created. It was established, that minimum values of surface work quality are achieved using polishing flexible elastic bands on the basis of polyethylene terephthalate and work cutting layer of elbor (LO) granularity of 0.5–1 micron (M0,5–M1) at 100 % the first concentration.
Conclusions. Also it was demonstrated, that the formation of high quality parameters of working surfaces of details, made from new composites on the base of aluminum, essentially depends from type of the polish tape, parameters cutting materials and material of elastic elbor tape base. The recommendation for the production was developed.
Keywords: elastic elbor tape; polish surfaces of details of rotation; surface roughness; parameters cool working; parameters cutting.
Estimation of the Elastic Properties of Traction Chains in Problems of Dynamics Conveying Vehicles / Gorbatenko J.P., Zakora O.V. - K. Наукові вісті НТУУ “КПІ”. – 2015. – N 2. – P.
Background. Tasks of the research of dynamic parameters of conveying vehicles with a chain traction body are usually solved without structural peculiarities of traction chains. Analysis of dynamic models of a number of escalators typical character concerned with the use of a significant amount of traction chains types and sizes, so there is need to create universal experimental and calculated methodology for assessing the elastic properties of traction chains.
Objective. Improving the reliability of the dynamic model parameters of the traction body of escalators by combination of methods for determining the stiffness coefficients of traction chains (physical and virtual simulation of the experiment).
Methods. Stiffness coefficient was determined using the experimental methods (physical experiment). Stiffness coefficient of traction was determined using the finite element method. The values of stiffness coefficients of traction chains, which are obtained experimentally for estimation of the dynamic characteristics of the escalator traction body.
Results. The coefficients of stiffness of virtual model chain were determined; correction factors with the data obtained as a result of physical experiment were determined. In order to analyze and compare the calculating methods of stiffness coefficient of chain, dynamic characteristics (AFR) traction chain for different values of stiffness coefficient were built.
Conclusions. Performed calculations and investigations of the dynamic model of escalator traction body confirm the possibility of determining the elastic properties (stiffness coefficients) of traction chains with the use of virtual method with an adjustment factor, which is calculated basing on the comparison and analysis of the values of the coefficient stiffness, which are determined experimentally and virtual methods.
Keywords: tractive element; dynamic model; stiffness coefficient; dynamic characteristics (AFR).
The Vacancy Formation Energy in the Quasi-Harmonic Approximation from First Principles Calculations / Zamulko S.O - K. Наукові вісті НТУУ “КПІ”. – 2015. – N 2. – P.
Background. This work is related to the theoretical calculation of the vacancy formation energy in the context of finding an answer to two unsolved questions. Firstly, there is no single answer to the question of calculations accura-cy of the vacancy formation energy. Secondly, the existing phenomenological theories tacitly assume that the vacancy formation energy and entropy of vacancy formation do not depend on temperature.
Objective. The aim of the study was to investigate the effect of temperature factor on the free energy of vacancy for-mation and its components in a number of metals within the quasi-harmonic approximation.
Methods. The vacancy formation energy and entropy in FCC Al, Ag, and Pd are determined as a function of tem-perature using ab initio methods within a quasi-harmonic approximation.
Results. It was shown, that the vacancy formation energy substantially increases with temperature in all cases, which is related to the thermal lattice expansion. Such increase of the vacancy formation energy is compensated by the vi-brational vacancy formation entropy contribution. The latter appears to be strongly increasing with temperature in the case of Mo.
Conclusions. However, a thermodynamic analysis shows that such increase of vacancy formation energy in the process of calculation is largely underestimated. The latter is compensated by contribution from vibrating entropy of vacancy formation and strongly increases with temperature. Such underestimation is related to certain problems in quasi-harmonic approximation.
Keywords: density functional theory; vacancy formation energy; first principles; quasi-harmonic approximation.
Dependence Between Microhardness and Magnetic Resistance of Electrodeposited Fe-Cr and Fe-Ni Alloys / Kolesnyk Ie.V., Klymenko O.P., Dudka A.M. - K. Наукові вісті НТУУ “КПІ”. – 2015. – N 2. – P.
Background. For thin metal coatings indirect determination of mechanical properties is an actual task. Its accom-plishing requires establishing the dependencies between different groups of coatings properties.
Objective. The aim of research is identification of the dependence between characteristics of mechanical and magnet-ic properties of thin electrodeposited coatings, particularly – the iron-based alloys.
Methods. 50 mm thick Fe-Cr and Fe-Ni alloys obtained at the temperature of 55 °C and the cathode current density of 10 A/dm2 from the sulphate electrolytes, containing iron ions (80 g/l) and chromium or nickel ions (from 1 to 40 g/l), have been investigated with definition of microhardness, magnetic resistance, surface morphology, phase composition and preferred crystal orientations.
Results. The dependencies of microhardness and magnetic resistance of the Fe-Cr and Fe-Ni alloys on the concen-tration of the alloying elements in the electrolyte have common non-linear nature and correlate well with the results of precise measurement of the spacing of crystal lattice of the alloys. At that, the content of chromium and nickel in the coatings is not significant impact factor on the properties.
Conclusions. The found identical character of microhardness change and magnetic resistance of the alloys indicates significant influence of residual macrostrain on mechanical and magnetic properties of Fe-Cr and Fe-Ni alloys. The reason for non-linear changes in macrostrain in the investigated alloys are the features of structure formation, which can be observed in the formation of surface morphology and preferred crystal orientations.
Keywords: electrodeposited coatings; alloy; Fe-Cr; Fe-Ni; microhardness; magnetic resistance; macrostrain; surface morphology; preferred crystal orientations.
Regularities of Thinck Layer Creation Coating on the Rotation Details Surface /Stepanchuk A.М., Shevchuk M.B., Biriukovych L.О., Vorobey A.P. - K. Наукові вісті НТУУ “КПІ”. – 2015. – N 2. – P.
Background. Creation of theoretical and technological basics of obtaining thick layer coating from composite materials on the rotation details surface is actual task. In order to solve this problem, it is necessary to determine dependencies of coating properties from characteristics of material and obtaining conditions.
Objective. The purpose of this paper is conduction a model studies of thick layer coating of composite materials based on solid refractory compounds and self-fluxing alloys on the detail with a horizontal axis of rotation obtaining process. Investigation of the influence of density granules rotational angular velocity of shape, size of the particles (granules) form and size on the centrifugal force during sealing and impregnation, as a result, the density of the obtained products was assumed.
Methods. Acting stand for obtaining thick layer coatings by centrifugal impregnation of solid granules of refractory compounds melts of metals and alloys using induction heating in the external and internal surfaces of revolution was developed. Study of the properties and structure of the obtained materials was carried out using modern methods of determining the density of composite materials and optical and electron microscopy, computer technology.
Results. Physical and mathematical models of obtaining thick layer coatings on the surfaces of details of rotation were developed. It allows evaluation of the influence of pellets density, the angular velocity of shape rotation, particles (pellets) size and mold size to centrifugal force during sealing and impregnation, as a result, obtained products density. The dependence of the sealing force of the powder density is linear, the radius of the particles – cubic, the angular velocity – quadratic, and shape radius – a linear dependence. Real samples of coatings have been got and density and structure depending on the particle size distribution of solids part of coatings were studied. Obtained results are adequate for the proposed theoretical dependences in this work.
Conclusions. The regularities of structure formation and composite thick layer coatings properties, obtained by centrifugal impregnation of starting materials composition, and conditions of receipt.
Keywords: thick layer coating; solid refractory compounds; self-fluxing alloys; centrifugal impregnation; grain size; structure; density.
Method of Designing of Multiorder Diffractive Lenses / Kolobrodov V.G., Kuchugura I.O., Kuchugura Ie.O. - K. Наукові вісті НТУУ “КПІ”. – 2015. – N 2. – P.
Background. Multiorder diffractive lenses differ from conventional diffractive lenses by operating simultaneously in several diffractive orders, which is achieved by increasing of the lens thickness. This is improved the manufacturability of lens.
Objective. The purpose of this paper is to develop a method of designing of multiorder diffractive lenses that provides the given optical performance of the lens.
Methods. The theoretical research of the lens properties is carried out. The dependence of the energy distribution in diffractive orders on the thickness coefficient μ is found. It is proposed a method for calculating multiorder diffractive lenses according to which the lens simulation is performed.
Results. It is determined that calculating the optimal coefficient thickness can send the required amount of energy to neighboring diffractive orders. It was shown the example of the energy distribution by 40.5 % on each point. It was presented calculating method of the number of phase jumps m, which determines the thickness of the lens.
Conclusions. The paper describes a method of designing of multiorder diffractive lenses by which multifocality can be achieved; in particular it was shown the example of bifocal lens calculation. Bifocal lens designed by the proposed method provides sharp vision of objects located at a distance of 33 cm and infinity. It can be used as an intraocular lens in the optical system of the eye model “cornea + lens”.
Keywords: multiorder diffractive lens; intraocular lens; coefficient of thickness; diffractive order.
Diffuse Radiator of Variable Brightness Based on Matrix of Light-Emitting Diodes with the Scatterer /Mikheenko L.A., Kalmykova O.V. - K. Наукові вісті НТУУ “КПІ”. – 2015. – N 2. – P.
Background. Lately there has been a rapid development of digital optoelectronic systems with matrix photodetectors, but further improvement of these systems is largely constrained by insufficient methods and tools for measuring their energy characteristics.
Objective. The purpose of this article is to develop a new method of calculation and analysis of the radiator of varia-ble brightness based on matrix of light-emitting diods with the scatterer.
Methods. A system with the matrix light-emitting diodes and the scattering glass is used as a diagram of the radiator. The dependence of the brightness on the output aperture of the radiator on its design parameters is investigated. Its mathematical modeling and search for the most appropriate values of the individual parameters are carried out.
Results. A new method of calculation and analysis of the radiator with the scatterer based on the account of influence of the spatial structure of the matrix and the point spread function or function scattering line of the scattering ele-ment was worked out. The basic parameters of the radiator with the scatterer were given. There were the step of the matrix of light-emitting diodes and coefficient of the indicatrix providing the minimum heterogeneity of radiation and the maximum brightness of the output aperture.
Conclusions. The results have shown that the proposed scheme of the radiator is perspective for measuring the energy characteristics of the matrix photodetectors of the digital optoelectronic systems.
Keywords: metrology; radiometric measurements; digital optoelectronic systems; optical radiometry; matrix photo-detectors.
Technique of Strength Increasing of Working Pipeline Parts with the Help of Well-Bond Goints / Tymchik G.S., Podolian A.A. - K. Наукові вісті НТУУ “КПІ”. – 2015. – N 2. – P.
Background. Getting high efficiency of enhancing pipeline of small and medium diameter using well-bond joints is complicated, because of the low modulus of elasticity compounds used to form the under-join layer.
Objective. Development of the strength increasing technique of the high pressure pipelines parts using the well-bond joints is the aim of this study.
Methods. Strength increasing technique of a working pipeline with the help of well-bond joints was used.
Results. The strength increasing technique of the high pressure pipelines parts using the well-bond joints, which are filled with molten metal with a high modulus of elasticity, is offered. The operations of forming the under-joint layer with parameters providing achievement of maximum tension decrease level in strengthened pipe providing and equal load distribution between a side of a pipe part under repair and joint covering are considered.
Conclusions. The offered technique gives an opportunity to increase efficiency of strengthening the medium and small pipes diameter pipes.
Keywords: coupling; nondestructive control; diagnostics; repair; gas passage line; pipeline; pressure.
Projection-Grid Method of Elasticity Problems Solution in Flight Dynamics / Tsybenko A.S., Konyukhov A.S. - K. Наукові вісті НТУУ “КПІ”. – 2015. – N 2. – P.
Background. The development of efficient projection-grid method for solving initial-boundary value problems of the elastic dynamics of the aircraft.
Objective. Theoretical study of numerical methods for solving the elastic dynamics of aircraft in order to create a ge-neralized method of numerical integration of initial-boundary value problems for discrete-continuum.
Methods. As a generalized mathematical description of the initial-boundary value problem by using the operator for-mulation of the first order main part. Approximate solution of initial value problems of elastic dynamics of aircraft represented as a linear form on the class of admissible functions of non-degenerate projective basis. Algebraization of the spatial variables is realized because of orthogonalization residuals of equations and boundary conditions for the system of functions defining non-degenerate weight basis. The greatest effect is achieved by computing the matching item in the projection and a weight basis in conjunction with the "weak" formulation of the Galerkin method in the form of the finite element method. The general form of the finite difference method is used for algebraization of un-known functions on a temporary argument. For solving systems of nonlinear algebraic equations on time layers, Newton's method and its modifications were applied.
Results. A general approach to solving the problems of the elastic dynamics of aircraft using the procedure of alge-braization based on projection-grid schemes of the method of weighted residuals. A posteriori estimates for the accu-racy, convergence and stability of numerical solutions of the elastic dynamics of aircraft were presented.
Conclusions. The developed technique of algebraization tasks in elastic dynamics of aircraft can be widely used in the simulation of the dynamics of liquid carrier rockets in different parts of the flight.
Keywords: dynamics of aircraft; initial-boundary value problem; Galerkin method; finite element method; finite-difference schemes; accuracy; convergence; stability.
Astrelin I.M., Krimets G.V., Molyuga A.I., Suprunchuk V.I.
Recycling of Phosphogypsum in Complex Mineral Fertilizer
Background. In the production of phosphate fertilizers and phosphoric acid accumulation environmentally unsafe on the course – hosphogypsum. To date, in the territory of Ukraine is in the dumps about 30 million tons of phosphogypsum.
Objective. To get from phosphogypsum with using waste technologies complex NPCaS-fertilizer.
Methods. Processing phosphogypsum in a relatively “soft” operating conditions, without the involvement of high-temperature (1173–1753 K) processes. Conducted a research of two-stage utilization processing of typical phosphogypsum into complex fertilizer with composition 7,9 % N, 37 % P2O5, 35 % Ca, 1,8 % S, containing phosphorus in the form of Сa(H2PO4)2, СaHPO4 (at a ratio P2O5(w-soluble)/P2O5(overall) = 94%), and the nitrogen – in the form (NH4)2SO4. The first stage of the process is implemented decomposition of phosphogypsum at temperature (323 ± 5) K by solutions of (NH4)2СO3 at pH > 5,1 with formed a precipitate (suspension) СаСO3 in solution (NH4)2SO4. In the second stage formed a thick slurry is processed (without filtration separation СаСO3) by solutions of sub-standard phosphoric acid without external heating at the support of the pH of the medium to 6,8–6,9. The final solid fertilizer is drying of slurry in apparatus of type “fluid process” at temperature (390–423) K.
Results. The final solid fertilizer, consumer quality is tested on samples of soil for agricultural purposes. Conclusions. On the base of phosphogypsum is received a complete fertilizer for little-stage non-waste technology in environmentally sound conditions.
Keywords: phosphogypsum; complex fertilizers; suspension; little-stage technology; substandard phosphate acid.
Technology of Obtaining Microcrystalline Cellulose from Non-Wood Plant Raw Material / Barbash V.A., Nagorna Ju.M. - K. Наукові вісті НТУУ “КПІ”. – 2015. – N 2. – P.
Background. For the countries without free timber storage, Ukraine in particular, there is an actual problem of searching alternative sources of plant raw material for production of cellulose-containing products, microcrystalline cellulose (MCC) specifically. Nowadays imported cotton and sulfate bleached cellulose are the main raw materials for MCC production.
Objective. The purpose of research is to study the possibility of obtaining MCC from more cheap, annually renewable plant material growing in Ukraine in huge amount, fibers of technical plants and stalks of grain plants (flax, hemp, kenaf, corn, miscanthus) using ecologically safe methods of its obtaining.
Methods. Technology of obtaining MCC from technical and grain plants was performed with using of alkali-sulfite-alcohol delignification and oxide-organosolvent treatment. The quantity of stages obtaining microcrystalline cellulose technological process was decreased due to combining of bleaching and hydrolysis processes using mixture of acetic acid and hydrogen peroxide with ratio 70:30 % respectively.
Results. MCC from flax and hemp fibers meet the requirements of national and European Pharmacopoeia. MCC from kenaf fibers, corn and miscanthus stalks don’t meet indices by their sulfate ash content and electrical conductivity, which is related to still high ash content in these fiber samples.
Conclusions. Technological conditions of obtaining MCC from bast fibers, which meets the requirements of national and European Pharmacopoeia, was proposed. It is recommended to use this product as filler for drugs production in pharmaceutical industry.
Keywords: organosolvent delignification; raw plant material; oxide-organosolvent treatment; microcrystalline cellulose.
Remediation of Anionic Dye (Bromphenol Blue) from Aqueous Solutions by Solvent Sublation / Obushenko T.I., Tolstopalova N.M., Kulesha O.Yu., Astrelin I.M. - K. Наукові вісті НТУУ “КПІ”. – 2015. – N 2. – P.
Background. The accumulation of toxic effluent components is a considerable hazard to water resources potential of the country. It particularly relates to waste water pollutants belonging to II–IV hazard classes such as organic dyes and diluents.
Objective. The goal of this research was to investigate the main principles of Bromphenol Blue remediation from water by solvent sublation technique and to determine optimum process conditions.
Methods. Bromophenol blue (BB), an anionic dye, was removed from aqueous solution by solvent sublation of a BB – hexadecylpyridium complex (sublate) into isopentanol. The pH of the solution was determined by potentiometric method. Dye concentrations of the sample solutions were measured with the use of absorption spectroscopy.
Results. The effects of the following parameters on the solvent sublation were experimentally studied: the molar ratio of hexadecylpyridium chloride (HPC) to BB, pH of the aqueous phase, the removal process duration, type of organic solvent, the size of bubbles generated in the sparger and the addition of electrolytes (like KCl) and nonhydrophobic organic compounds (like ethanol). By making central composite orthogonal design and deriving second order mathematical model with the aid of MS Excel 2003 it was found that the maximum efficiency of depicted process can be attained in a case of carrying it out under the following optimum conditions: temperature 10 °C, surfactant/dye molar ratio 1.94:1; process duration – 15.3 min.
Conclusions. Within this research the main principles of Bromophenol Blue removal from water by solvent sublation were investigated. The second order experiment statistical model was derived with the use of central composite orthogonal design. The maximum relative standard deviation was equal to 4,7 %. Optimum conditions were determined: According to obtained results the highest level of BB elimination reached within the experiment was equal to 97.5 % and the residual dye content didn’t exceed the maximum allowable concentration (the M.A.C.) of acidic dyes 0.25 mg/dm3.
Keywords: dye; Bromphenol Blue; optimum conditions; mathematical model; sublatе spectrophotometry.