Influence Of Various Values Research Articles

Structure of the Device and Experimental Research of Verifying the Functionality of Elements of Easy-Dropped Construction

This article analyzes the current state of explosion protection in the world. As a result of the analysis, it was determined that the main modern method of explosion protection is the use of easy-dropped construction (hereinafter - EDC). There are various methods for calculating the required area of the EDC, but to confirm the reliability of the calculations, the selection of the material that performs the function of the EDC, geometrical parameters and excess pressure of operation, it is necessary to conduct experimental research. The existing experimental devices for testing EDC for excess explosion pressure are given. The designs and drawbacks of these devices are considered. The design features of the constructed unit for checking the functionality of elements of easy-dropped construction (hereinafter referred to as the unit) and the main advantages compared to other experimental units are described. A scheme of the device and its structure is given. The required amount of propane-butane was calculated to obtain an excess explosion pressure of 5 kPa. Based on the results of the tests, a graph of the change in the excess pressure of the explosion over time is plotted and the value of the excess pressure of the explosion in a closed volume depending on the concentration of the gas mixture of propane-butane with air, which is formed in the closed volume, and the change in the excess pressure of the explosion after the activation of the EDC were investigated. A graph of the influence of the concentration of the gas-air mixture on the excess pressure acting on the EDC is plotted. The design parameters of the device and its location, the limit values of the excess pressure of the explosion, the minimum amount of gas to create the required excess pressure of the explosion are substantiated. The considered device provides an experimental determination of the values of the overpressure of the operation of EDC of typical sizes and allows conducting experimental research of the operation of the EDC under the influence of various values of the overpressure of the explosion with the required accuracy.

IMPACT OF FRICTION COEFFICIENT VARIATION ON TEMPERATURE FIELD IN ROTARY FRICTION WELDING OF METALS – FEM STUDY

A mathematical model is presented for investigating the temperature field caused by the rotary friction welding of dissimilar metals. For this purpose, an axisymmetric, nonlinear, boundary value problem of heat conduction is formulated with allowance for the frictional heating of two cylindrical specimens of finite length made of Al 6061 aluminium alloy and 304 stainless steel. The thermo-physical properties of materials change with increasing temperature. It was assumed that the coefficient of friction does not depend on the temperature. The mechanism of heat generation due to friction on the contact surface with the temperature field of samples is considered. The boundary problem of heat conduction was reduced to the set of nonlinear ordinary differential equations at time t relative to the values of temperature T at the finite elements nodes. The numerical solution of the problem was obtained with the inverse 2nd order differentiation method implemented in COMSOL FEM system (finite element method), with time step ∆t=0.1 (s). The influence of various values of friction coefficient is presented.

On the Question of the Attitude to Sports Practices in Orthodoxy

Introduction. The article is aimed at a comprehensive and holistic analysis of the judgments existing in Orthodox circles regarding physical culture and sports, reflecting the Orthodox worldview and its values. The novelty of the article lies in the empirical substantiation of the role of the physical and spiritual development of believers against the background of sports practices, as well as the substantiation of contradictions and problems of perception, sports practices in the conditions of the Orthodox worldview. Methodology and sources. A comprehensive approach to the problem of studying and analyzing sports practices is used as a methodological basis. The main research method in the work is an Internet survey.Results and discussion. According to the study, it should be noted that there is no unity among Orthodox people in understanding the role of physical culture in Orthodox spiritual development. Most people believe that the call for the development of their body is not the work of the church, they do not see any sin in the underdevelopment of their body. This is the result of the influence of various values that are in one or another society in which people live. Therefore, it is especially important to emphasize the role of the church in the educational process of physical culture among young people and the younger generation.Conclusion. In general, the author of the article comes to the conclusion that there is no unity among Orthodox people in understanding the role of physical culture in Orthodox spiritual development.

Investigation of onset of velocity transition in free convection over an inclined flat plate by PIV

In this work, the experimental investigation of onset of velocity transition in free convection boundary layer over a 45° inclined plate has been carried out. Experiments were performed on a 150 mm long flat plate with uniform heat flux ranging from 100 W/m2 to 5000 W/m2. Particle image velocimetry (PIV) technique was used to determine the flow characteristics over an inclined plate. The impact of various hydrodynamic parameters such as shear stress and velocity boundary layer thickness for defining or identifying the onset of velocity transition has been discussed. Also, the influence of various values of the heat fluxes on the onset of transition has been examined. It has been observed that the initiation of transition is first manifested as an increase in the overall velocity boundary layer thickness. Therefore, the thickness of the velocity boundary layer has been used as a hydrodynamic measure to determine the streamwise distance from the leading edge where the transition begins. This distance decreases with an increase of heat flux. The critical Rayleigh number for the onset of the transition under various heating conditions has been reported. For example, the critical Rayleigh numbers for the beginning of transition at heat fluxes of 100 W/m2 and 5000 W/m2 are 6.07 × 108 and 2.73 × 109 respectively.

Decision-Making Analysis Based on Fermatean Fuzzy Yager Aggregation Operators with Application in COVID-19 Testing Facility

This research article is devoted to establish some general aggregation operators, based on Yager’s t-norm and t-conorm, to cumulate the Fermatean fuzzy data in decision-making environments. The Fermatean fuzzy sets (FFSs), an extension of the orthopair fuzzy sets, are characterized by both membership degree (MD) and nonmembership degree (NMD) that enable them to serve as an excellent tool to represent inexact human opinions in the decision-making process. In this article, the valuable properties of the FFS are merged with the Yager operator to propose six new operators, namely, Fermatean fuzzy Yager weighted average (FFYWA), Fermatean fuzzy Yager ordered weighted average (FFYOWA), Fermatean fuzzy Yager hybrid weighted average (FFYHWA), Fermatean fuzzy Yager weighted geometric (FFYWG), Fermatean fuzzy Yager ordered weighted geometric (FFYOWG), and Fermatean fuzzy Yager hybrid weighted geometric (FFYHWG) operators. A comprehensive discussion is made to elaborate the dominant properties of the proposed operators. To verify the importance of the proposed operators, an MADM strategy is presented along with an application for selecting an authentic lab for the COVID-19 test. The superiorities of the proposed operators and limitations of the existing operators are discussed with the help of a comparative study. Moreover, we have explained comparison between the proposed theory and the Fermatean fuzzy TOPSIS method to check the accuracy and validity of the proposed operators. The influence of various values of the parameter in the Yager operator on decision-making results is also examined.

Development of Conditions of Surface Biosynthesis of Prodigiosin Pigment Serratia marcescens

Background. Prodigiosin is a red pigment produced as a secondary metabolite by Serratia marcescens , characterized with unique tripyrrole structure and exhibits such pharmacological characteristics as antitumor, antimicrobial, antioxidant, immunodepressant, and also used in various branches of biotechnology as a natural dye or marker of petroleum products. However, pigmentation is only present in a small percentage of isolated cultures among different S. marcescens strain, therefore, the effectiveness of biotechnological productivity is primarily determined by the producer strain, as well as the rational conditions for biosynthesis. Pigment production levels are strongly influenced by various factors, such as the set and ratio of the components of the culture medium (concentration of a particular substrate, C:N ratio) and cultivation conditions (temperature, pH). Besides, the use of relatively low-cost substrates is an important condition for reducing financial costs for the production of culture media and increasing the level of biosynthesis of the target product. Therefore, the determination of the influence of the culture medium for the strains of S. marcescens and the identification of the main factors contributing to the accumulation of the pigment prodigiosin to develop biotechnologies for the production of drugs for therapeutic purposes is relevant. Objective. The purpose of the paper is investigation of pigment-forming strain of S. marcescens under cultivation conditions on the surface of solid nutrient media, determination of biochemical features, and rational cultivation conditions that contribute to the accumulation of the pigment prodigiosin. Methods. The strain of S. marcescens isolated from the bentonite clays of Kurtsivskyi deposit (Crimea, Ukraine) was cultured in Petri dishes on solid nutrient media with different temperatures, pH, carbon and nitrogen sources. The influence of various values of the studied factors was established by the level of pigment accumulation, which was determined by the gravimetric method. The acidity of the nutrient medium was determined by the potentiometric method. Results. The influence of the initial pH values of solid nutrient medium, temperature, and various sources of carbon and nitrogen on the accumulation of pigment during the cultivation of the strain S. marcescens was studied. The temperature, pH, and compounds, sources of carbon and nitrogen, favorable for obtaining the pigment, were determined. Conclusions. It was found that the rational parameters for cultivation are the temperature +27–28 °C and the acidity of the nutrient medium of 6–7, and the best sources of carbon and nitrogen for prodigiosin accumulation are glycerin and peptone (as well as casein hydrolysate, yeast extract or ammonium (nitrate) inorganic compounds), respectively.

Demulsification of Liquid Membrane Emulsion using High Voltage Glass Coated Electrode in Batch System

Demulsification is one of the key processes in emulsion liquid membrane application. This study involved the effect of electrical field on demulsification of water in oil using batch high voltage demulsifier system. This technique widely used because of its advantages of easy manipulation of applied field direction and strength, offers cost–effective separation and minimal environmental impact combined with mechanical simplicity. Influence of various values of frequency (400–1500 Hz) and voltage was studied experimentally using Alternate Current (AC) High Voltage Demulsifier with insulated electrode. The emulsion consists of kerosene as organic phase, sulfuric acid as internal phase and span 80 (3 and 5 w/v %) as a surfactant. The effect of emulsion preparation such as homogenizer speed, internal phase and surfactant concentrations on the stability of water–in–oil emulsion was also investigated. The results showed that the attractive forces between the water droplets under an electrical field increase by raising the applied electrical field strength. Meanwhile, the time required for the emulsion to separate and coalescence under electrical field increased when the stability of emulsion increased.

Effect of supplemental damping on seismic response of base isolated frames under near & far field accelerations

The seismic isolation, as a passive control method of structures and an innovative approach in resistant seismic design, significantly reduces the response of structural systems induced by strong ground motions. The performance of these systems in Near Fault (NF) ground motions with large pulses is different from that of Far Fault (FF) ground motions. It is indicated that the effects of near field earthquake with large velocity pulses can bring the seismic isolation devices to critical working conditions. To overcome this problem, the application of viscous damper is represented as an approach to improve the performance of these systems in near field earthquakes. In the present paper, through modeling six base isolated structures, the seismic responses were studied under near field and far field earthquakes. Nonlinear time history analyses were performed, applying the finite element software of ABAQUS to study the influence of various values of supplemental damping (5% ∼ 40%) on the responses of base isolated structures. The results demonstrated that, generally, by increasing supplemental damping ratio under near field earthquakes, the base displacement decreases; however, the stories relative displacements and accelerations increase. It is observed that by increasing supplemental damping ratio under far field earthquakes, the base displacement and the stories relative displacements decreases; however, the stories accelerations increase. Based on the analyses, these variations proved to be more prevalent under near field earthquakes and taller structures.

A combined effect of frictional and elastic moment against truck turning on forced hunting of a bogie car.

In this paper, the authors theoretically analyze the forced hunting of a high-speed vehicle, which runs on a rail with sinusoidal irregularity, in reference to lateral direction of the rail. The authors used the half-body vehicle model having a small clearance in the connection position between the truck frame and the bolster anchor, where the spring and friction are connected in series against truck turning. Consequently, the authors clearly showed that there appeared some very complicated nonlinear phenomena in comparison with the resonance curves of no body. Then, the authors showed the influence of various values on the vehicle vibration, for example, the frictional force of the side bearer, the wheel tread conicity, the yawing damper, and the turning stiffness of the truck. Further-more, the authors proposed target values for the designing of vehicles.