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Results in Journal EUREKA: Physics and Engineering: 386

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, Ruslan Skrynkovskyy,
EUREKA: Physics and Engineering, Volume 4, pp 49-60;

Recommendations are worked out in relation to the evaluation of longevity and quality of underground metallic pipelines in the conditions of corrosion fatigue. The features of early exposure of crisis (before accident) situations are set. A complex qualimetric criterion is offered for determination of level of quality of pipeline by the account of his technological specific. The elements of investment project and methodology of estimation of resource are worked out. and also influences of factors of different nature on risks and possibility of accident of gas pipelines. The model of corrosion fatigue of metal is based on power criterion of destruction mechanics according to which there is an act of destruction in an arbitrary elemental volume of a material if the total irreversibly scattered energy of plastic deformation for all load cycles will reach a critical value equal to the energy of destruction. In order to control the corrosion process taking the polarization potential into account, a criterion relation is used to determine the rate of residual corrosion of a metal in the defect of the insulation coating, in particular, at the top of the crack, which is an anode region. The adhesive strength criteria of biocorrosive aggressive soil, mechanical criteria for the stress intensity factor, the criterion of corrosion resistance defect, criterion correlation for estimating the speed of residual corrosion in defect of insulation coating with imposed diagnostic weight characteristics and diagnostic value of tests, that complement, clarify and improve the corrosion monitoring system of pipelines, helpful for controlling and optimizing of the corrosion process, and Development of recommendations for anti-corrosion protection of metal are used in areas with non-stationary plastic deformation.
Vladimir Andreychuk, Yaroslav Filyuk
EUREKA: Physics and Engineering, Volume 4, pp 25-32;

An experimental facility for measuring and recording the flux density of solar radiation is designed and installed. An electrical circuit is developed and a pyranometer model is developed to measure the level of solar radiation, and it is graduated with a Soler Power Meter DT-1307 solar radiation flux meter. The time distribution of the flux density of solar energy is analyzed and the surface energy density of solar radiation is calculated for Ternopil. The influence of climatic conditions on the energy of solar radiation is determined. Analytical dependencies are obtained on the basis of comparison of the measured values of the flux density of solar radiation and the cloud cover taken from meteorological services. The energy potential of solar radiation during 2012-2015 in the western region of Ukraine is calculated, as well as the average monthly and average annual energy density of solar radiation. It is determined that the annual average density of the solar energy flux is 1045.9 kW∙h/m2, and its deviation does not exceed 5%. It is shown that the most favorable months for the use of solar energy are from March to September of each year.
, Viktor Marynchenko, Mariana Hyvel
EUREKA: Physics and Engineering, Volume 4, pp 3-10;

The possibility of using natural mineral adsorbents - clinoptilolite and schungite - in the adsorption purification of water-alcohol solutions of different concentrations was studied using the example of impurities of ethanol of acetaldehyde and ethyl acetate. The feasibility of studying the above-mentioned minerals for the adsorption of simple organic substances is justified. The best concentration of a water-alcohol solution for adsorption of acetaldehyde 80-85 vol.%, ethyl acetate-40 vol.% is experimentally established. The rational duration of phase contact for adsorption of acetaldehyde is from 10 to 20 minutes, for adsorption of ethyl acetate - 5 minutes. An explanation for the dependence of the sorption efficiency on the ethanol content in a water-alcohol solution is proposed based on the known dependencies of the rectification factor on the ethanol concentration. The larger the rectification factor, the less the hydrogen bond of this impurity with ethanol and the easier it is to sorb it from ethanol by mineral adsorbents. The practical and economic feasibility of using the mineral adsorbent clinoptilolite of Ukrainian origin in the preparation of alcoholic beverages instead of imported active coal is shown. It is determined that to purify water-alcohol solutions from aldehydes, which most worsen the taste of alcoholic beverages, it is more expedient to use clinoptilolite as an adsorbent. It is shown that the use of clinoptilolite for the preparation of vodkas from non-standard rectified alcohol will improve the tasting indicators of the final product.
Oleg Burdo, , Aleksandr Zykov, Igor Zozulyak, Julia Levtrinskaya, Elena Marenchenko
EUREKA: Physics and Engineering, Volume 4, pp 18-24;

The advantages of wave technologies in comparison with traditional thermal technologies are considered. The aim of research is using of innovative wave technologies to intensify the processes of heat and mass transfer in the processes of dehydration and extraction, while reducing energy costs. A classification of the mechanisms of intensification of heat and mass transfer processes is proposed. Technical methods for intensifying heat and mass transfer during the processing of plant raw materials using technologies for targeted delivery of energy are developed. Samples of equipment are presented that implement technologies of directed energy action and innovative products obtained at these facilities. The results of experimental studies of drying in the microwave and infrared fields are shown.
, Sərdar Yusub Qasımov
EUREKA: Physics and Engineering, Volume 4, pp 42-48;

The problem of synthesis of the boundary optimal control of the cooling process of media with heat conductive viscosity is investigated. In addition to the distributed parameters, the concentrated parameters act on the system. This is due to the fact that the temperature of the external environment is unknown and varies according to a given law. As a result, the process is described by a system of partial differential equations and ordinary differential equations. In this case, heat transfer occurs at the right end of the rod. This complicates the obtaining of a solution of this boundary-value problem in an explicit form. But it is possible to establish the existence and uniqueness of the solution of the corresponding boundary-value problem for concrete admissible controls. The criterion of quality is a quadratic functional and it is required to build control in the form of feedback. First by the Fourier method, the problem under consideration is formulated in an infinite-dimensional phase space. As a result, the problem of synthesis of optimal control in a functional space is obtained. To solve this problem, the dynamic programming method is used. To do this, let’s introduce the Bellman functional and obtain the Bellman equation, which this functional satisfies. The solution of this equation allows to find the control parameter in the form of a functional defined on the set of the state function. Further, by introducing the corresponding functions, feedback control is constructed for the original problem. Unlike program control, this allows to influence the behavior of the system at any time, that is, to ensure the self-regulation of the process. However, let’s note that the difficulties in solving this problem are connected with the justification of the proposed method. This is established by the investigation of a closed system.
Yulia Kharybina, Yaroslav Pitak
EUREKA: Physics and Engineering, Volume 4, pp 11-17;

The paper shows that presence of such phases as mullite, corundum is required in order to obtain high quality refractories that are able to work effectively under the conditions of the simultaneous effects of corrosive environments, high temperatures and pressure, sudden changes in temperature. The structures of Al2O3 – SiO2 – CaO – Р2O5 system are examined in the materials in which the formation of defined phases is probably. Based on data it is carried out partitioning of the system on the elementary tetrahedrons. The data on the lengths of tie lines, volumes, the asymmetry degree and the eutectic temperature of elementary tetrahedrons are given. The geometric-topological characteristic of the phases of this system are presented. The choice of oxides compositions areas for the production of refractories is justified based on the obtained results.
, Andrii Oliinyk
EUREKA: Physics and Engineering, Volume 4, pp 61-72;

In connection with the global increase in the intensity of use of working equipment related to high-risk facilities and the expiry of the service life limit, the question arises of determining the actual technical condition and forecasting the residual resource. From the analysis of the approaches to determining the technical state and on the analysis of regulatory documents, it becomes clear that the regulated methods of assessing the technical state are obsolete, such that they do not ensure the reliability of the obtained control results. A new technique for determining the actual technical state through monitoring the level of stresses in the body of high-risk objects is proposed. The new technique takes into account additional physical and mechanical parameters that affect the stress-strain state, and have not yet been used. In other words, the technique of multivariable control of stress determination was proposed. Mathematical models of the process of deformation and stress for cylindrical vessels with a spherical and conic dome operating under the action of high pressure are proposed.
, , Petro Lohvynenko, Volodymyr Dobryvechir
EUREKA: Physics and Engineering, Volume 4, pp 33-41;

In the paper the results of testing three types of FUCHS oils: Thermisol QH 120, Thermisol QH 10 and Thermisol QB 46 are discussed. The main attention is paid to critical heat flux densities evaluation because they create a basis for optimizing cooling intensity of any liquid quenchant. In the paper is underlined that any film boiling during quenching is undesirable since it is a reason for big distortion and non-uniform surface harness. It is shown that intensive quenching decreases distortion of steel parts during quenching. To eliminate film boiling during quenching in mineral oils, optimal temperature of oil should be chosen which maximize the first critical heat flux density and special additives should be used to decrease initial heat flux by creating surface micro-coating. Along with the evaluation of heat transfer coefficients, critical heat flux densities inherent to liquid quenchant must be measured first to optimize quenching processes. International DATABASE on cooling characteristics of liquid quenchants must include critical heat flux densities, initial heat flux densities, and heat transfer coefficients allowing optimizing and governing quenching processes.
Pavlo Katin
EUREKA: Physics and Engineering, Volume 3, pp 49-54;

As a result of the research, two directions for development of software architecture for low-power general purpose microcontrollers (LPGPM) are identified. The first, classical approach is the development using standard State patterns. The second is the development of programs, algorithms and structures based on mathematical analysis.The first direction is chosen in the work. The variant of the implementation of a typical pattern for development of software architecture (SA) in the form of a finite state machine (FSM) is proposed to discussion. This pattern allows to divide the development of the architectural part of the program for LPGPM and programming the LPGPM hardware. This approach makes it possible to divide the work of the software architect and the work of LPGPM hardware specialists. Advantage of the solution in comparison with the real time operating system (RTOS) is the saving of LPGPM hardware resources. In addition, it improves the readability of code and good testing prospects. The resulting architecture makes it possible to easily accompany the software and switch to other types of microcontroller. The disadvantage is an increase in the required amount of RAM with an increase in the number of states. It is this disadvantage that requires the application not only of experimental and engineering-intuitive methods, but also to continue research in the second direction.
Mourad Aouati
EUREKA: Physics and Engineering, Volume 3, pp 55-68;

A procedure for classifying objects in the space of N×2 factors-attributes that are incorrectly classified as a result of constructing a linear discriminant function is proposed. The classification accuracy is defined as the proportion of correctly classified objects that are incorrectly classified at the first stage of constructing a linear discriminant function. It is shown that, for improperly classified objects, the transition from use as the factors-attributes of their initial values to the use of the centers of gravity (COGs) of local clusters provides the possibility of improving the classification accuracy by 14%. The procedure for constructing local clusters and the principle of forming a classifying rule are proposed, the latter being based on converting the equation of the dividing line to the normal form and determining the sign of the deviation magnitude of the COGs of local clusters from the dividing line
Anton Silvestrov, Dmytro Zimenkov
EUREKA: Physics and Engineering, Volume 3, pp 12-21;

A complex physical phenomenon, first discovered by engineer J. Huber in 1951, is investigated. From the perspective of an external observer, the phenomenon is as follows: an electric current is passed through the wheel pairs of the car moving from the rail to the rail. The current, passing through the movable contacts of the wheels and rails, creates an additional (up to the moment of inertia) torque. The research task is to explain the reason for the occurrence of torque. Based on the analysis of individual components of the electrodynamic phenomenon discovered by Huber, an algorithm for the successive interaction of the individual components of the effect is found on the basis of the laws of classical electrodynamics: electric, ferromagnetic, and mechanical.The identity of the effect is explained, both for the wheel pair and for the bearing (Kosyrev-Milroy engine). For the first time, the cause of the appearance of the torque is revealed: relative movement of surface charges in the region of the movable electrical contact to the wheel body and the rails (or balls and guides). Moving charges unevenly magnetized ferromagnetic bodies according to the Biot-Savart-Laplace law. Due to the reduction in the clearance of the oncoming side of the wheel (or balls) and the increase on the trailing side, the pulling force from the oncoming side and, accordingly, the moment are more than on trailing side. The presented theoretical explanations completely correspond to the experimental investigation of the effect carried out by different scientists at different times.
Rahib Aqaqul Sailov, Fazil Ali Veliev, Qusni Kadir Kerimov
EUREKA: Physics and Engineering, Volume 3, pp 3-11;

As a result of experimental studies, a special mathematical model of raw cotton is developed. The effect of density change on the thermal conductivity coefficient is determined. A nonlinear differential equation of heat propagation in coils is obtained. The dependence of the density of raw cotton on the coil height is determined experimentally. The heat flux is intense propagating from denser layers of raw cotton to less dense ones. In a saturated form, the effect of density changes on the propagation of heat is less than in the coils. Pocket spontaneous heating occurs locally with sharp boundaries.An expression is found, which is the general solution of the mathematical model of heat propagation in raw cotton in coils, on the basis of which a number of physical real models can be constructed.The model allows to preliminarily give an estimation of the likely picture of the temperature field in the given microvolumes of raw cotton.
Dmytro Makarenko
EUREKA: Physics and Engineering, Volume 3, pp 41-48;

The article is devoted to the analysis of the composition and properties of dispersion-strengthened aluminum-based SAP-ISML composite materials, which are used in various industries, including the aviation. The properties of such materials have been analyzed with the aim of ensuring the management of their quality for rational use and subsequent disposal. Mathematical models of dependence of parameters of dispersed-hardened materials on the basis of aluminum of SAP-ISML type on the aluminum content and temperature are constructed.
Andrey Kholodkov, Aleksandr Titlov
EUREKA: Physics and Engineering, Volume 3, pp 31-40;

Currently, developers of modern refrigeration equipment, in accordance with the plans of the UN, are moving to natural refrigerants (hydrocarbons, carbon dioxide and ammonia) that do not have an adverse technological impact on the ecosystem of the planet. In domestic refrigeration technology, one of the options is absorption refrigeration units, the working body of which is an aqueous ammonia mixture with the hydrogen addition. Having a number of unique advantages over compression analogs, absorption systems are characterized by lower energy characteristics.As the analysis shows, the maximum thermodynamic losses in the absorption aggregates are concentrated in the generating unit when the ammonia is evaporated, it is purified from water vapor and transported to the evaporator. In this connection, the mathematical modeling of the thermal regimes of the reflux condenser is performed, which is responsible for purification and transportation of ammonia vapor.Modeling is carried out on standard designs of absorption refrigeration units taking into account reasonable assumptions and results of own experimental researches. A cellular model is used. Stationary operating modes are modeled due to the high thermal inertia of the processes in the reflux condenser.As a result, the perspective of the thermal insulation installation throughout the reflux section is shown, which makes it possible to increase the energy efficiency by 17 ... 22 %
Olena Teteriatnyk
EUREKA: Physics and Engineering, Volume 3, pp 22-30;

Conditions for the stabilizability of discrete almost conservative systems in which the coefficient matrix of a conservative part has no multiple eigenvalues are investigated.It is known that a controllable system will be stabilized if its coefficient matrix is asymptotically stable.The system stabilization algorithm is constructed on the basis of the solvability condition for the Lyapunov equation and the positive definiteness of P0 and Q1.This theorem shows how to find the parameters of a controlled system under which it will be asymptotically stable for sufficiently small values of the parameter e (P > 0, Q > 0).In addition, for a small parameter e that determines the almost conservatism of the system, an interval is found in which the conditions for its stabilizability are satisfied (Theorem 2).
Musbah Zaid Enweiji, Taras Lehinevych, Аndrey Glybovets
EUREKA: Physics and Engineering, Volume 2, pp 24-33;

Cross language classification is an important task in multilingual learning, where documents in different languages often share the same set of categories. The main goal is to reduce the labeling cost of training classification model for each individual language. The novel approach by using Convolutional Neural Networks for multilingual language classification is proposed in this article. It learns representation of knowledge gained from languages. Moreover, current method works for new individual language, which was not used in training. The results of empirical study on large dataset of 21 languages demonstrate robustness and competitiveness of the presented approach.
Iryna Svyatovets
EUREKA: Physics and Engineering, Volume 2, pp 9-15;

The problem is considered for constructing a minimax control for a linear stationary controlled dynamical almost conservative system (a conservative system with a weakly perturbed coefficient matrix) on which an unknown perturbation with bounded energy acts.To find the solution of the Riccati equation, an approach is proposed according to which the matrix-solution is represented as a series expansion in a small parameter and the unknown components of this matrix are determined from an infinite system of matrix equations.A necessary condition for the existence of a solution of the Riccati equation is formulated, as well as theorems on additive operations on definite parametric matrices. A condition is derived for estimating the parameter appearing in the Riccati equation.An example of a solution of the minimax control problem for a gyroscopic system is given. The system of differential equations, which describes the motion of a rotor rotating at a constant angular velocity, is chosen as the basis.
Obbozzhon Kuldashev, Ibrohimzhon Tojiboev
EUREKA: Physics and Engineering, Volume 2, pp 34-39;

The article presents the results of the development of the echolocation device for geophysical exploration at shallow depth. The principle of operation, block diagram and time diagrams of the echolocation device for geophysical exploration at shallow depths are outlined. The urgency of developing an echolocation device for geophysical exploration at shallow depth is revealed in the conditions of a lack of mineral resources, the need to replenish them with the help of discovering new deposits.It is analyzed that under the action of a shock wave, multi-frequency harmonic damped seismic waves are excited to the earth's surface, the frequency band of which is 1-200 Hz.When detonation generators are used to control the earth's crust, the duration of the impact pulse is on the order of one millisecond and the frequency range at 0.5 from the maximum amplitude of the echo signals is 20-400 Hz, which allows using higher-frequency harmonic components of echo signals to determine and classify the object at depth up to 100 m.Echolocation device for geophysical exploration is intended for detection and primary classification of objects by their acoustic rigidity and can be used for geophysical exploration at shallow depths (up to 100.0 m).
Alexander Goloskokov, Mykhailo Brodskyi
EUREKA: Physics and Engineering, Volume 2, pp 47-54;

The statement of the risk assessment problem of convergence trajectories of dynamic objects is formulated. An example of the solution assessment problem of the convergence trajectories of two dynamic objects is considered. Modeling of aircraft traffic taking into account the influence of random perturbations in MatLab is carried out. Relative projections of the trajectories of two aircrafts are constructed. An assessment of the occurrence of a conflict situation between two dynamic objects is obtained, the results of this problem are analyzed.The aim of research is developing an approach to risk assessment problem of convergence trajectories of dynamic objects.The problem is solved in the test case with the given initial conditions.Further development of the article consists in finding the probability of a conflict situation from the multidimensional Fokker-Planck-Kolmogorov equation.The process of aircraft traffic is described by the random Markov process of Ornstein-Uhlenbeck.conflict situation; forecasting; aircraft; conflict situation assessment; conflict probability; dynamic object; stochastic differential equation
Anna Danylchenko, Svetlana Kravchenko
EUREKA: Physics and Engineering, Volume 2, pp 16-23;

For the matching problem with vanishing arcs, an optimal algorithm based on the branch and bound method was developed to find the maximum matching in a bipartite graph [1].The algorithm takes into account the limits of compatibility procedures. The calculated experiment is aimed at proving the feasibility of paralleling of the optimal algorithm for solving the problem of scheduling the reception of medical procedures by patients for use in the sanatoriums of Ukraine.The experiment was carried out on computing platforms of different configurations with different computing power: a different number of processor cores, different amounts of memory, etc.Estimated minimum time scheduling, received at the computer platform with the maximum number of PCs is involved. Estimated time scheduling algorithm paralleling by using modifications of the branch and bound method is directly proportional to the number of vertices of a bipartite graph (which is equal to the sum of the number of procedures and the number of patients), the number of assigned procedures and restrictions.
Nikolai Kobasko
EUREKA: Physics and Engineering, Volume 2, pp 55-62;

Poly(Alkylene Glycol) polymers of inverse solubility (PAG) provide ideal uniform cooling for minimizing distortion and preventing crack formation during hardening machine components and tools. However, in spite of ideal cooling, from time to time, a big distortion takes place during hardening process. A reason for a big distortion development during hardening in PAG solutions is explained and an idea how to fix the problem is suggested. It is shown that at the end of cooling coating can be locally dissolved by a cold water flow creating local open area where martensite transformation starts first. Due to greater specific volume of martensite, it creates a big distortion. To solve the problem, one should interrupt cooling process or stop agitation before insulating coating is dissolved. To perform correctly proposed technology, cooling intensity of inverse solubility PAG polymers of 1–20 % were investigated on the basis of use of regular thermal condition theory. As a result, dimensionless effective numbers Kn were obtained for recipes development. A technique for solving the problem is proposed by author. Examples of calculations are provided.
Ganna Verovkina
EUREKA: Physics and Engineering, Volume 2, pp 3-8;

The article deals with some interpolation representations of stochastic processes with non-equidistance interpolation knots. Research is based on observations of the process and its derivatives of the first and second orders at some types of knots and observations of the process and its derivatives of the first orders at other types of knots. The necessary results from the theory of entire functions of complex variable are formulated. The function bounded on any bounded region of the complex plane is considered. The estimate of the residual of the interpolation series is obtained. The interpolation formula that uses the value of the process and its derivatives at the knots of interpolation is proved. Considering the separability of the process and the convergence of a row that the interpolation row converges to the stochastic process uniformly over in any bounded area of changing of parameter is obtained. The main purpose of this article is the obtained convergence with probability 1 of the corresponding interpolation series to a stochastic process in any bounded domain of changes of parameter. Obtained results may be applied in the modern theory of information transmission.
Iryna Shvedchykova, Julia Romanchenko, Inna Nikitchenko
EUREKA: Physics and Engineering, Volume 2, pp 40-46;

The distribution of the magnetic field in the working zones of synthesized polygradient media is studied using a computational experiment. The distribution of the magnetic field is carried out by the numerical finite element method, realized with the help of the ELCUT program complex. It is substantiated that instead of studying the field distribution in the entire interpolar zone of arbitrary structure, it can limited by the field studies in a characteristic, periodically repeating region, taking into account its symmetry. For the studied structural compositions of polygradient media using the ELCUT program tools, two-dimensional geometric models of the working interpolar zones have been developed, taking into account generally accepted engineering assumptions.A comparative analysis of the distribution of induction and force function of the magnetic field in the working gaps of the synthesized structures of a lamellar polygradient medium of a given configuration is performed.
EUREKA: Physics and Engineering, Volume 1, pp 61-68;

The article considers the non-stationary initial-boundary problem of thermal conductivity in axially symmetric domain in Minkowski space, formulated as equivalent boundary integral equation. Using the representation of the solution in the form of a Fourier series expansion, the problem is reformulated as an infinite system of two-dimensional singular integral equations regarding expansion coefficients. The paper presents and investigates the explicit form for fundamental solutions used in the integral representation of the solution in the domain and on the border. The obtained results can be used in the construction of efficient numerical boundary element method for estimation of structures behavior under the influence of intense thermal loads in real-time.
Denys Kukhtar
EUREKA: Physics and Engineering, Volume 1, pp 38-44;

The modern geodetic equipment allows observations as soon as possible, providing high accuracy and productivity. Achieving high accuracy of measurement is impossible without taking into account external factors that create influence on an observation object. Therefore, in order to evaluate an influence of thermal displacement on the results of geodetic monitoring a mathematical model of horizontal displacement of above-ground pipelines was theoretically grounded and built. In this paper we used data of experimental studies on the existing pipelines "Soyuz" and "Urengoy - Pomary - Uzhgorod". Above-ground pipeline was considered as a dynamic system "building - environment". Based on the characteristics of dynamic systems the correlation between the factors of thermal influence and horizontal displacement of the pipeline axis was defined.Establishing patterns between input factors and output response of the object can be useful not only for geodetic control, but also for their consideration in the design of new objects. It was investigated that the greatest influence on the accuracy of geodetic observations can create dispersion of high-frequency oscillations caused by daily thermal displacement. The magnitude of displacement exceeds actual measurement error.The article presents the results of calculation of high-frequency oscillations of above-ground gas pipeline.The result made it possible to substantiate the accuracy and methodology of geodetic observations of the horizontal displacement of pipeline axes taking into account an influence of cyclical thermal displacement.Research results were recommended for use in practice for enterprises that serve the main gas pipelines and successfully tested by specialists of PJSC "Ukrtransgaz" (Kharkiv, Ukraine) during the technical state control of aerial pipeline crossing in Ukraine and also can be used to form the relevant regulations.
Nikolay Poluyanenko
EUREKA: Physics and Engineering, Volume 1, pp 53-60;

The nonlinear feedback shift registers of the second order inare considered, because based on them it can be developed a generator of stream ciphers with enhanced cryptographic strength.Feasibility of nonlinear feedback shift register search is analyzed. These registers form a maximal length sequence, using programmable logic devices.Performance evaluation of programmable logic devices in the generation of pseudo-random sequence by nonlinear feedback shift registers is given. Recommendations to increase this performance are given. The dependence of the maximum generation rate (clock frequency), programmable logic devices on the number of concurrent nonlinear registers is analyzed.A comparison of the generation rate of the sequences that are generated by nonlinear feedback shift registers is done using hardware and software.The author suggests, describes and explores the search method of nonlinear feedback shift registers, generating a sequence with a maximum period. As the main result are found non-linear 26, 27, 28 and 29 degrees polynomials.
Petro Venherskyi
EUREKA: Physics and Engineering, Volume 1, pp 45-52;

Based on the laws of conservation of mass and momentum the basic equations of motion with unknown quantities velocity and piezometric pressure are written. These equations are supplemented with boundary and initial conditions describing the motion of compatible flows. Based on the laws of motion continuum, received conditions contact on the common border interaction of surface and groundwater flows. Variational problems formulated compatible flow. Energy norms of basic components of variational problem are analyzed. Correctness of constructing variational problem arising from construction of the energy system of equations that allow to investigate properties of the problem solution, its uniqueness, stability, dependence on initial data and more. Energy equation of motion of surface and groundwater flows are derived and investigated. It is shown that the total energy compatible flow depends on sources that are located inside the domain or on its border.
Hadi Amineh, Nataliya Kosach
EUREKA: Physics and Engineering, Volume 1, pp 21-29;

Issues on building an integrated model of the automotive product quality assessment are studied herein basing on widely applicable methods and models of the quality assessment. A conceptual model of the automotive product quality system meeting customer requirements has been developed. Typical characteristics of modern industrial production are an increase in the production dynamism that determines the product properties; a continuous increase in the volume of information required for decision-making, an increased role of knowledge and high technologies implementing absolutely new scientific and technical ideas. To solve the problem of increasing the automotive product quality, a conceptual structural and hierarchical model is offered to ensure its quality as a closed system with feedback between the regulatory, manufacturing, and information modules, responsible for formation of the product quality at all stages of its life cycle. The three module model of the system of the industrial product quality assurance is considered to be universal and to give the opportunity to explore processes of any complexity while solving theoretical and practical problems of the quality assessment and prediction for products for various purposes, including automotive.
Oksana Yegorova
EUREKA: Physics and Engineering, Volume 1, pp 30-37;

Chitosan is a cationic polymer derived by deacetylation of chitin obtained from crustaceans. Biodegradable and mucoadhesion properties of chitosan have recently led to increasing the interest. Chitosan can be used as raw material for the manufacture of films, membranes and fibers, in such branches as medicine, agriculture, veterinary medicine, biotechnology, cosmetics and pulp, and paper industry. Previously it was investigated that in Aspergillus Niger cell wall constituents, chitin comprises of 42 % and also researchers confirmed that the chitosan content of fungi depends on fungal strains, mycelial age, cultivation medium and conditions [1]. In the paper the results of the study of physical and chemical properties of obtained samples of chitosan are shown. The influence of initial parameters of the process on the quality of chitosan is investigated. Use of the biomass to produce chitosan on the basis of the developed methodology is shown. It is found that the resulting chitosan is characterized by low values of ash content, moisture content and the value is within 75–82 %. A further development of the scientific basis for the creation of an efficient, competitive and environmentally safe technologies for utilization mycelial biomass of the fungus Aspergillus Niger with the production of a valuable product is chitosan, which is in contrast to the known allows to reduce production costs by 10–80 % (by using not concentrated solutions of chemicals and low temperature process. This leads to reducing the cost of reagents and electricity. The calculation was performed on indicators such as net present value, internal rate of return and payback period.) The use of the developed technological schemes in practice allows utilization of mycelial waste with the aim of obtaining from them valuable product of chitosan, and to ensure the improvement of ecological situation in the region.
Andrii Shkop, Musii Tseitlin, , Valentina Raiko
EUREKA: Physics and Engineering, Volume 1, pp 13-20;

The effect of the concentration and disperse composition on the flocculation strength to mechanical influence is investigated. It is found that the residual rate of floccules sedimentation after the mechanical influence at a constant rate of flocculant has a maximum value at a concentration of solids in the slime in the range of 7-30 g/dm3. The best results are obtained in all the experiments at a solids concentration of 10 g/l. It is found that at a concentration up to 7 g/l and more than 30 g/l, the floccules is formed. They have the lowest residual rate after mechanical influences. With increasing content of the solid fraction of 40-100 microns over 15%, the strength of floccules increases. They retain their shape and relatively high sedimentation rate even after mechanical influence. The obtained data allow to recommend correction of the slime composition before flocculant injection both the concentration close to the optimum, and the content of size fraction of 40-100 mm more than 15 %.
Nikolai Kobasko
EUREKA: Physics and Engineering, Volume 1, pp 3-12;

A method for optimizing chemical composition of steel is proposed and a correlation is established to reduce cardinally alloy elements in existing steel grades that results in high compressive residual stresses at the surface of intensively quenched steel parts and increasing strength and ductility of material due to super- strengthening phenomenon. The algorithm of optimization consists in reducing alloy elements in existing alloy steel in 1.5 – 2 times and then lowering step-by-step content of steel, beginning from the most costly alloy element and ending the most cheaper one, until established correlation is satisfied. The range of reduction is minimal and during computer calculations can be chosen as 0,001wt%. The proposed approach can save alloy elements, energy, increase service life of machine components and improve environmental condition. The method is a basis for development of the new low hardenability (LH) and optimal hardenability (OH) steels.
Nikolai Kobasko
EUREKA: Physics and Engineering, Volume 6, pp 29-36;

The paper discusses patented in Ukraine a new intensive quenching IQ–2 technology based on film boiling resonance effect [1]. Namely, the paper discusses improving of the batch intensive quenching (IQ) process known as IQ-2 method by the use of hydrodynamic emitters installed in quench tanks. The hydrodynamic emitters produce oscillating waves in the quench media with the frequency of the film boiling process creating a resonance effect. Two- and three-step IQ-2 processes are considered. Specifics of the heat transfer during the IQ-2 process are presented with focusing on the first stage of quenching where film and nucleate boiling processes are taking place. Examples of production IQ-2 equipment and loads processed are also presented. Application of hydrodynamic emitters in the IQ water tanks in addition to currently used propellers is considered in details. It is shown that the proposed new method can fully eliminate the film boiling process resulting in significant reduction of part distortion during quenching. Further evaluation of the proposed method is needed for its implementation in heat treating practice.
, Vitaly Yevdokymenko, Ievgen Polunkin
EUREKA: Physics and Engineering, Volume 6, pp 11-18;

The catalytic process for methanol production by synthesis gas conversion under the conditions of mechanochemical activation (MCA) of copper-zinc-aluminum oxide catalyst in the temperature range 160–280 °C at a pressure of 0.1 MPa are investigated. The use of mechanical action force is one of the promising ways to improve the activity of heterogeneous catalysts designed to simplify the manufacturing process lines, improving the efficiency of catalytic processes and reduce the cost of the target product. Given the importance of technology for methanol production on copper-zinc-aluminum oxide catalysts and high demand for methanol in the world [1–3], clarification of the peculiarities of the process of methanol production by synthesis gas conversion in terms of mechanical load on the catalyst is important in scientific and applied ways.It is established that specific catalytic activity, performance of methanol synthesis catalyst and the conversion of initial reagents are increased in the conditions of mechanochemical activation, because of the increasing concentration of defects and formation of additional active centers. It is revealed that mechanochemical treatment of copper-zinc-aluminum oxide catalyst can reduce reaction initiation temperature and optimum temperature synthesis by 20–30 °C, and increase the maximum performance of the catalytic system.Increase of the catalyst activity under mechanical stress is explored by increase of defect concentration of crystal lattice of the catalyst, as confirmed by the tests of catalyst surface structure by scanning electron microscopy, Raman spectroscopy and X-ray analysis.A new effective method for synthesis gas conversion into the methanol under conditions of mechanochemical activation of the catalyst can be used in industry as an alternative to methanol production at high pressures.
Anatoly Nadtoshy
EUREKA: Physics and Engineering, Volume 6, pp 59-64;

An analysis is conducted of the basic risks that occur when managing the projects of deep-sea archeological research. It is proposed to consider possible risks of such projects in the form of a general set of risks that contains subsets of the identified and unidentified risks. Based on the generalization of existing experience of conducting underwater archaeological research and with regard to the peculiarities of their execution by using TV-controlled unmanned underwater vehicles, the main risks of such operations are identified. A classification of risk factors is proposed, which takes into account weather and hydrological conditions in the area of operations, peculiarities of the underwater situation, technological and technical provision of underwater archaeological research, possible obstacles from the navigation in the explored area and errors in geographical coordinates of fulfilled work, as well as the human factor. Additionally, environmental, organizational and financial risks, which the project team is aware of, are defined as directly related to planning the projects of deep-sea archeological research. A generalized risk register is developed of the projects' deep-sea archaeological studies as theoretical foundation for designing the models of risk management and their quantitative evaluation when planning financial and temporal resources for such projects.
Yaroslav Yakymechko, Myroslav Sanytsky, Bohdan Chekanskyi
EUREKA: Physics and Engineering, Volume 6, pp 19-28;

The processes of CaO hydration have been investigated under various temperature conditions and while introducing of H3PO4, H2SO4,H2SiO3, H3BO3 and their sodium salts into water. The binding composites were obtained based on thin-grinded quicklime with 95.6 % of active CaO and MgO. The phase composition of the hydration products were clearly confirmed mainly by XRD and thermal analyses. Under cryogenic conditions (temperature –4˚C) the rate of the reaction between CaO and CO2 of the air increased and extra amount of calcite was formed. During CaO hydration with the introduction of additives containing SO42- and BO33- anions the formation of Portlandite crystals (mainly of lamellar habit) was observed. Rietveld method demonstrates the increase in half-width of 01–2, 02–1, 01–3, 022 and 122 reflections in Portlandite stone indicating the occurrence of stresses that alter the rate of crystals growth in definite directions. The formation of Ca(OH)2 fine crystals of hexagonal lamellae shape results in the increase of their surface, the contact area and bond strength that leads, in its turn, to the increase in mechanical strength of the structure.
EUREKA: Physics and Engineering, Volume 6, pp 46-52;

The aim of the article is a hardening of the surface steel layers due to the combination treatment. Samples of steel 38Cr2MoAl were hardened by complex chemical and thermal treatment such as carburizing and subsequent boriding. It was established that surface double-layer hardening for steel 38Cr2MoAl with sequential saturation with atomic carbon (during carburizing) and atomic boron (during furnace boriding) at different temperatures allowed to form a boride layer with transition zone.The obtaining transition zone can improve operational properties of machine parts and tools by micro-friability reduction of diffusion layer. An optimal mode of complex chemical-thermal treatment (CTT) was obtained for the regime, which includes carburizing at 950 °C for 2 hours, boriding at 950 °C for 2 hours, which allows to get the best value for the surface hardness of 22 GPa with a maximum overall diffusion layer 1.4 mm. Due to the technology of combined treatment we can significantly reduce treatment time compared to traditional hardening means and significantly improve product performance properties due to the transition zone between the borides and the matrix of machine elements. The technology can be used in enterprises where there is any hardening furnace without additional installation or conversion of equipment.
Ganna Shchutska
EUREKA: Physics and Engineering, Volume 6, pp 37-45;

The work proved computer photometric method for determining the water concentration in the line textile samples. The aim of the article is the testing of computer visualization techniques to determine the sorption characteristics of textile structural components. The main result is the determination of the actual empirical distribution functions in linear liquid samples. For this purpose one of the boundaries of the test material was set in contact with coloured water. Thanks to the diffusion properties of the material, water spread along the sample changing its brightness. Using of visualization enabled to determine the concentration in the textile sample. Experimental regressive dependence of concentration in a sample of different factors was developed. The proposed concentration dependence of the water from the coordinates and time has the form of exponential function. Exponent index is a characteristic feature of this material, which is characterized its absorption properties. Constants that describe the intensity of a linear sorption of the sample of material were defined. The results can be used in predicting of the water distribution and process modeling of discrete material structure.
Grigoriy Zrazhevsky,
EUREKA: Physics and Engineering, Volume 6, pp 53-58;

Technological processes in the energy sector and engineering require the calculation of temperature regime of functioning of different constructions. Mathematical model of thermal loading of constructions is reduced to a non-stationary initial-boundary value problem of thermal conductivity. The article examines the formulation of the non-stationary initial-boundary value problem of thermal conductivity in the form of a boundary integral equation, analyzes the singular equation and builds the fundamental solution. To build the integral representation of the solution the method of weighted residuals is used. The correctness of the obtained integral representation of the solution in Minkowski space is confirmed. Singularity of the fundamental solution is investigated. The boundary integral equation and fundamental solution for axially symmetric domain for internal problem is built. The results of the article can be useful for numerical implementation of boundary element method.
Olga Haidai, Vladimir Pilyavskiy, Yevgenij Shelud’Ko, Yevgenij Polunkin
EUREKA: Physics and Engineering, Volume 6, pp 3-10;

A new way to overcome the disadvantages of ethanol motor fuels by introducing of multifunctional additives based on carbon nanoscale clusters in their composition is given. It is shown that the modified nanoclusters contribute to the formation of supramolecular structure of ethanol fuels in the form of solvent domains around the nanoparticles. Orientation local ordering of these supramolecular structures changes such physicochemical properties of oxygenate fuels as dielectric constant and the load-bearing capacity of the liquid phase in the dynamic mechanical load.The influence of synthetic carbon spheroidal clusters on the corrosive properties of ethanol fuels is studied. It is shown that by using small amounts (0.01 % wt.) of nanocluster-based additives in the composition of mixed fuel E–85 it is unnecessary to introduce the anticorrosion additives.The effect of nanocarbon clusters on the tribological properties of ethanol motor fuels is studied. A decrease in damage of the metal surface for friction pairs of the fuel pumps is observed with the introduction of carboxylic nanoclusters into the ethanol fuel. This indicates the occurrence of friction processes in the hydrodynamic regime due to the increased bearing capacity of the fuel.It is shown that the introduction of additives based on carbon nanoscale clusters into the ethanol fuel allows to create a high-performance motor fuel with improved performance.
Published: 30 September 2016
EUREKA: Physics and Engineering, Volume 5, pp 67-80;

The most popular methods for dynamic risk measures – Value-at-Risk (VaR) and Conditional VaR (CVaR) estimating were analyzed, description and comparative analysis of the methods were fulfilled, recommendations on the use were given. Results of the research were presented in the form of a classification scheme of dynamic risk measures estimating that facilitates the choice of an estimation method. The GARCH-based models of dynamic risk measures VaR and CVaR evaluation for artificially generated series and two time series of log return on a daily basis of the most well-known Asian stock indexes Nikkey225 Stock Index and CSI30 were constructed to illustrate the effectiveness of the proposed scheme. A qualitative analysis of the proposed models was conducted. To analyze the quality of the dynamic VaR estimations the Cupets test and the Cristoffersen test were used. For CVaR estimations the V-test was used as quality test. The tests results confirm the high quality of obtained estimations. The proposed classification scheme of dynamic risk measures VaR and CVaR estimating may be useful for risk managers of different financial institutions.
Kateryna Fesenko, Volodymir Mogylatenko, Anatoliy Fesenko, Vyacheslav Kosyachkov, Maksym Fesenko
EUREKA: Physics and Engineering pp 55-60;

The paper proposes a new method of production of bilayer and double-sided castings with differentiated structure and properties using the technology of in-mold modification of the initial melt, smelted in a single melting furnace, which ensures formation of hard wear-resistant white iron as the working layer, and formation of ductile shock-resistant cast iron with nodular graphite as the core or the mounting part. Numerous laboratory studies confirm the feasibility of the proposed method and provide conditions ensuring differentiation of structure and properties in local parts or layers of castings. The prospects of the method for manufacturing a wide range of industrial castings are indicated.
Sergii Koval, Sergii Gedulyan
EUREKA: Physics and Engineering pp 16-21;

Using computer modeling it is analyzed an influence of additives - modifiers, developed a technique of search and compositions of multicomponent polymer-cement composites from dry mixes for repair of building structures to the levels of performance of rheological, mechanical and operational properties in excess of regulatory, while ensuring compatibility with the concrete base.
Pavel Khristo
EUREKA: Physics and Engineering pp 60-78;

It was conducted a calculation of the parameters of the T-shaped equivalent circuit of a large asynchronous engine with the use of precise G-shaped equivalent circuit for nominal data and some characteristic sizes of the machines. It was chosen the calculation method of the control value of the multiplicity of a critical moment on the basis of a comparison of different options to determine this value was done. It was obtained a dependence of the multiplicity of the critical moment from the estimated value of the magnetizing current, taking into account the effect of displacement and saturation of leakage flux flow of stator and rotor windings due to the analytical interpretation of graphical method for finding the critical moment of the pie chart on the basis of experimental data of idle speed experiment and three experiments with short circuit.
Dmitriy Odarchenko, Andriy Odarchenko, Tatyana Karbivnychaya, Alina Sergienko
EUREKA: Physics and Engineering pp 31-41;

The article is devoted to the improvement of methodological approaches to the assessment of the quality and authenticity of food raw materials and frozen products through scientific justification of signatures of properties of reversible liquid part of them. For the first time it is introduced the concept of "signature" to assess the quality and authenticity of raw materials in technologies of frozen semi-finished and food products, which is a physical quantity and has a quantitative value and indicator of the state and properties of the subject of research in whole and indicates the growing and storage conditions, species and authenticity. Method of sample preparation is developed and scientifically proved. This method involves cyclic use of freezing and centrifugation of animal and plant origin and provides a liquid phase, which is colloidal solutions and is characterized by resistance to sedimentation during freezing, thawing, and therefore can be used as a sample at quality assessment. Theoretical and practical knowledge about the changes of electrical and physical, optical, cryoscopic and thermodynamic properties in meat, fish, vegetables, berries and mushrooms are received further development.
Haider Ali Muse, Yuri Machehin
EUREKA: Physics and Engineering pp 3-15;

Wave propagation is a fundamental phenomenon occurring in several physical systems. The spectra have been used by others to develop optical frequency standards. The process can potentially be used for frequency conversion in fiber optic network. In this system the dispersive properties can be controlled by the optical lattice making it possible to achieve phase-matched four wave mixing, like look the process taking place in the photonic crystal fibers (PCFs). In this paper will focus on two such systems the propagation nonlinear wave in photonic crystal fibers and the propagation of matter waves in optical lattices.
Inna Pitak, Valery Shaporev, Tetiana Novozhylova, Dmytro Nechyporenko
EUREKA: Physics and Engineering pp 22-30;

The article describes methods to intensify the processes of biodegradation. The results of the investigations of waste biodegradation process modeling of waste and the intensification of these processes are given. Generalized mathematical model of emission of biogas at the landfill is developed and methods of process intensification in the body of the landfill are proved. As a result of research, microbiological and biochemical processes in the body of the landfill are analyzed, the main factors affecting the intensity of the processes are revealed and their impact is analyzed. It was concluded that the landfill is a biochemical reactor, where interrelated heat and mass transfer processes occur in the dense bed through which the gas is filtered and internal sources of heat. It was developed a complete mathematical model allowing estimating based on the equations of material and heat balances, the rate of biogas reactor. A model and calculation method for the analysis of heat and mass transfer processes in a dense bed with internal heat sources and to calculate the emission of biogas at design and operation of the landfill-reactor were given. Possible ways of intensifying the process of biodegradation in the reactor were revealed on the basis of analysis of the equations of the mathematical model describing the process in the reactor and the theory of microbiological processes of this class.
Olga Serdiuk
EUREKA: Physics and Engineering pp 42-48;

The paper presents the concept of approach to the research and evaluation of the processes of intellectual activity associated with the enrichment of the knowledge base. A feature of the research of the process dynamics is the need of simultaneous consideration of such diverse factors as the complexity of information perception, the presence of the deviations of the response from the standard in the process of reproduction and accounting of the test time. A significant influence on the methods of optimization of the knowledge base enrichment process is exerted by a considerable duration of the task learning process. This causes the use of the multifactor experimental design theory to accelerate the progress towards the optimum. The research results can be used in the development of technologies for efficient knowledge assimilation, automation of skills, and also in the development of expert systems for diagnostics of the processes of intellectual activity.
Volodymyr Koval
EUREKA: Physics and Engineering pp 49-54;

The basic stages of developing an information model of finishing work of the interior of industrial and housing buildings under the control of the developer agent on the construction site are considered in the article. The automation levels in modern CAD systems, which are necessary to ensure the implementation of each stage, are analyzed. It is proposed a sub-system of formation of information model of decision-making for finishing work, which is able to provide automation of the use of standards, selection of the most optimal solutions based on the algorithm of greed, as well as design solutions to minimize execution time of finishing work with ensuring appropriate quality
Oleg Avrunin, Maksym Tymkovych, Tetiana Kononenko
EUREKA: Physics and Engineering, Volume 1, pp 21-30;

During the work we analyze the process of neuronavigation in terms of using different approaches for aligning the operational volume at surgical stage in respective to the preplanning data. The work is dedicated to capabilities to visualize the operating region of surgical intervention relatively to cranial landmarks for neuronavigation. We analyzed the principles of selection of anatomical landmarks. We give practical advice on the choice of anatomical landmarks with respect to system of image analysis. Based on processes of image analysis and image processing we show necessity of utilization specialized anatomical landmarks. At this research we propose utilize the cranial landmarks on outer edge of cranium. It was confirmed the possibility of their automated determination. Was shown the necessity of intracerebral landmarks binding to the cranial landmarks. The proposed approach to selection of anatomical landmarks can be applied in neuronavigation for simplification process of their extraction and their calculation.
Haider Ali Muse Ali Muse
EUREKA: Physics and Engineering, Volume 1, pp 3-13;

The development of all optical communications could benefit from the index guiding photonic crystal fibers. In communication the photonic crystal fibers could provide many new solutions. Conventional optical fibers have within the last decades revolutionized the communications industry and it is today a mature technology being pushed to its limit with respect to properties such as losses, single mode operation and dispersion. The spectra have been used by others to develop optical frequency standards. The process can potentially be used for frequency conversion in fiber optic network. In this system the dispersive properties can be controlled by the optical lattice making it possible to achieve phase-matched four wave mixing, like look the process taking place in the photonic crystal fibers. In this paper we will discuss the use of photonic crystal fibers in communications.
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