Clarification Of Aqueous Suspensions With A High Content Of Suspended Solids In Rapid Sand Filters

The presented work is devoted to solving the actual problem of increasing the efficiency of rapid sand filters with granular filling, which operate at a constant filtration rate when cleaning suspensions with a relatively high concentration of contaminants. The proposed mathematical model for clarifying the suspension by filtration consists of three interconnected blocks: clarified, filtration, and hydraulic. Convenient dimensionless mathematical dependencies are obtained for calculating the concentrations of contaminants and sediment from the height of the filter and suspension in the filtrate; head loss in the filter loading; the effective time of the filter (the duration of the filter cycle). The design of the experimental setup and the methodology for conducting experimental studies and mathematical processing of the results are valid. The results of experimental studies of the suspension filtering process through the granular loading are presented, and the obtained data is analyzed. Measurement of pressure losses in the filter loading is performed when a suspension is passed with a relatively high concentration of contaminants at various filtration rates. The nature of the change in the filtration rate with time and height (length) loading at various filtration rates and initial contamination concentrations is determined. Measured variable concentration of suspended matter in filtered water and retained contamination over time. As a result of the experiments, it is confirmed that an increase in the concentration of retained contaminants S leads to an increase in the parameter Δn/n. Upon reaching a certain value of the concentration of the retained sediment S (in our case S=30 g/dm3), an increase in the relative specific volume of the sediment greater than Δn/n0=0.65 is not observed. It is established that an important characteristic of the retained sediment is the ratio of the volume concentration of the sediment to the volume concentration of solid particles in this sediment γ=Csd/Сs. The values of the adhesion and detachment of particles of contaminant in the particles of the material loading =4,9; =0,009. The results of experimental studies in general confirm the correctness and reliability of the obtained analytical dependencies

Vortex Polarity Switching in Magnets with Surface Anisotropy

Vortex core reversal in magnetic particle is essentially influenced by a surface anisotropy. Under the action of a perpendicular static magnetic field the vortex core undergoes a shape deformationof pillow- or barrel-shaped type, depending on the type of the surface anisotropy. This deformation plays a key point in the switching mechanism: We predict that the vortex polarity switching is accompanied (i) by a linear singularity in case of Heisenberg magnet with bulk anisotropy only and (ii) by a point singularities in case of surface anisotropy or exchange anisotropy. We study in details the switching process using spin-lattice simulations and propose a simple analytical description using a wired core model, which provides an adequate description of the Bloch point statics, its dynamics and the Bloch point mediated switching process. Our analytical predictions are confirmed by spin-lattice simulations for Heisenberg magnet and micromagnetic simulations for nanomagnet with account of a dipolar interaction.Comment: 17 pages, 15 figure

Педагогічна діагностика в системі фізичного виховання учнів загальноосвітніх навчальних закладів

У монографії розкрито зміст і механізми реалізації педагогічної діагностики в навчально-виховному процесі учнів загальноосвітніх закладів. Визначено сутність її змісту й структури та спрямованість під час вивчення фізичної культури в школі. Для викладачів вищих навчальних закладів, учителів загальноосвітніх закладів,аспірантів, студентів, усіх, хто цікавиться проблемою навчання фізичної культури

Justification of the Methodological Bases for the Management of the Radio Resource of Special Purpose Radio Communication Systems Under Conditions of Prior Uncertainty

The problem of substantiation of methodological bases of radio resource management of military radio communication systems in the conditions of a priori uncertainty is solved in the work. The object of research is the military radio communication system. One of the most problematic places in the management of military radio resources is the inability to carry out a hierarchical management of the parameters and modes of operation of both individual radios and the military radio system as a whole. This reduces the efficiency of the system itself and the efficiency of its application. The scientific problem is solved by substantiating the methodological principles of radio resource management of military radio communication systems in conditions of a priori uncertainty. During the research, the authors used the main provisions of the theory of queuing, the theory of automation, the theory of complex technical systems, as well as general scientific methods of cognition, namely analysis and synthesis. The novelty is that in the course of work: – the purpose of functioning of an operative management subsystem of a radio resource of military radio communication systems is formulated; – indicators and criteria of functioning efficiency of military radio communication systems are determined; – decomposition of the solution of this problem into problems depending on the signal and noise situation is carried out. An approach based on the hierarchical decomposition of the functional structure of networks, the behavior of which is described by stochastic differential (or difference) equations of the high dimension state, into a number of interconnected but simpler functional structures is used for the functional description of military radio communication systems. It will allow to make a decomposition of the state of the military radio system and increase the efficiency of decision-making on adjusting the modes of operation and parameters of the military radio system in real time. The research results should be used at the stage of operational management of parameters and modes of these systems operation

Justification of Ways Increasing the Immunity of Special Purpose Radio Communications

The object of research is the military radio communication system. One of the most problematic areas in the military radio resources management is the interference of military radio systems and facilities. A number of works have been devoted to the study of ways to increase the noise immunity of military radio communication systems and facilities. However, the known works contain some research results by scientists, which are aimed at increasing the noise immunity of military radio communication systems and devices and do not have a comprehensive approach. This work solves the problem of substantiating ways to increase the noise immunity of military radio communication systems and facilities. The scientific problem is solved by substantiating the methodological principles of increasing the noise immunity of military radio communication systems in conditions of a priori uncertainty. During the research, the authors used the main provisions of the queuing theory, the theory of automation, the theory of complex technical systems, as well as general scientific methods of cognition, namely analysis and synthesis. The novelty is that in the course of work: – the purpose of functioning of the noise protection system of military radio communication systems is formulated; – indicators and criteria for increasing the noise immunity of military radio communication systems have been determined; – decomposition of the solution of this problem into problems depending on the signal and noise situation is carried out. An approach based on the hierarchical decomposition of the networks functional structure, the behavior of which is described by stochastic differential (or difference) equations of the high dimension state, into a number of interconnected but simpler functional structures is used for the functional description of military radio communication systems. The proposed approach to describe the behavior of military radio systems will allow to decompose the military radio system state and increase the efficiency of decision-making to adjust operating modes and parameters in real time. The results of the research should be used at the stage of parameters operational management and modes of the system operation

The Problem of Hydraulic Calculation of Pressure Distribution Pipelines

Most production technologies require a uniform flow path of liquid from pressure distribution pipelines. To achieve this goal, it is proposed to introduce polymer additives into the liquid flow or to use converging distribution pipelines with a continuous longitudinal slot in the wall. To reduce the uneven operation of the distribution pipeline during discrete liquid dispensing, it is proposed to use cylindrical output rotary nozzles with a lateral orthogonal entry of the jet into the nozzle. The problem is the lack of methods for accurate hydraulic calculation of the operation of distribution pipelines. Adequate calculation methods are based on differential equations. Finding the exact solution of the differential equation of fluid motion with variable path flow rate for perforated distribution pipelines is urgent, because it still does not exist. The available calculation methods take into account only the right angles of separation of the jets from the flow in the distribution pipeline. These methods are based on the assumption that the coefficient of hydraulic friction and the coefficient of resistance of the outlets are constant along the flow. A calculation method is proposed that takes into account the change in the values of these resistance coefficients along the distribution pipeline. The kinematic and physical characteristics of the flow outside the distribution pipeline are also taken into account. The accuracy of calculating the value of the flow rate of water distributed from the distribution pipeline has been experimentally verified. The error in calculating the water consumption by the method assuming that the values of the resistance coefficients are unchanged along the distribution pipeline reaches 18.75 %. According to the proposed calculation method, this error does not exceed 6.25 %. However, both methods are suitable for the design of pressure distribution pipelines, provided that the jet separation angles are straight. Taking into account the change from 90° to 360° of the angle of separation of the jets from the flow in the distribution pipeline will expand the scope and accuracy of calculation methods

Computational modeling and molecular dynamics simulations of mammalian cytoplasmic tyrosyl-tRNA synthetase and its complexes with substrates

<p>Cytoplasmic tyrosyl-tRNA synthetase (TyrRS) is one of the key enzymes of protein biosynthesis. TyrRSs of pathogenic organisms have gained attention as potential targets for drug development. Identifying structural differences between various TyrRSs will facilitate the development of specific inhibitors for the TyrRSs of pathogenic organisms. However, there is a deficiency in structural data for mammalian cytoplasmic TyrRS in complexes with substrates. In this work, we constructed spatial structure of full-length <i>Bos taurus</i> TyrRS (<i>Bt</i>TyrRS) and its complexes with substrates using the set of computational modeling techniques. Special attention was paid to <i>Bt</i>TyrRS complexes with substrates [L-tyrosine, K⁺ and ATP:Mg²⁺] and intermediate products [tyrosyl-adenylate (Tyr-AMP), K⁺ and PP_i:Mg²⁺] with the different catalytic loop conformations. In order to analyze their dynamical properties, we performed 100 ns of molecular dynamics (MD) simulations. MD simulations revealed new structural data concerning the tyrosine activation reaction in mammalian TyrRS. Formation of strong interaction between Lys154 and <i>γ</i>-phosphate suggests the additional role of CP1 insertion as an important factor for ATP binding. The presence of a potassium-binding pocket within the active site of mammalian TyrRS compensates the absence of the second lysine in the KMSKS motif. Our data provide new details concerning a role of K⁺ ions at different stages of the first step of the tyrosylation reaction, including the coordination of substrates and involvement in the PP_i releasing. The results of this work suggest that differences between ATP-binding sites of mammalian and bacterial TyrRSs are meaningful and could be exploited in the drug design.</p

Development of the Method of Structural-parametric Synthesis of the Subsystem of Interference of Special Purpose Radio Communication Systems

The object of research is the military radio communication system. One of the most problematic areas in the management of military radio resources is the interference of military radio systems and facilities. A number of works have been devoted to the research of ways to increase the noise immunity of military radio communication systems and facilities. However, the known works contain some results of research by scientists aimed at increasing the noise immunity of military radio systems and facilities and do not have a comprehensive approach. In this article, the problem of developing a method of structural-parametric synthesis of the noise protection subsystem of special purpose radio communication systems is solved. The scientific problem is solved by formalizing the problem of structural-parametric synthesis of the noise protection subsystem of military radio communication systems, starting with its mathematical description and synthesis of the quantitative and qualitative structure of the noise protection subsystem. In the course of the research, the authors used the main provisions of the queuing theory, the theory of automation, the theory of complex technical systems and general scientific methods of cognition, namely analysis and synthesis. The novelty of this technique is the synthesis of the structure of the military radio system and the parameters of the radio system in the context of electronic conflict. This technique is multi-criteria, in which the parameters are different in importance. The basis of this technique is the principle of nonlinear scheme of A. Voronin compromises. This technique allows to: – to synthesize the structure of the radio communication system in the conditions of electronic conflict; – to determine the optimal number of radio communication devices to ensure management tasks in the conditions of electronic conflict; – to substantiate a set of mechanisms to increase the noise immunity of the noise protection subsystem in the conditions of electronic conflict. The results of the research should be used at the stage of planning and operational management of the structure and parameters of military radio communication systems