Vapour condensation in cloud cores produces small droplets that are close to one another in size. Droplets are believed to grow to raindrop size by coalescence due to collision. Air turbulence is ...thought to be the main cause for collisions of similar-sized droplets exceeding radii of a few micrometres, and therefore rain prediction requires a quantitative description of droplet collision in turbulence. Turbulent vortices act as small centrifuges that spin heavy droplets out, creating concentration inhomogeneities and jets of droplets, both of which increase the mean collision rate. Here we derive a formula for the collision rate of small heavy particles in a turbulent flow, using a recently developed formalism for tracing random trajectories. We describe an enhancement of inertial effects by turbulence intermittency and an interplay between turbulence and gravity that determines the collision rate. We present a new mechanism, the 'sling effect', for collisions due to jets of droplets that become detached from the air flow. We conclude that air turbulence can substantially accelerate the appearance of large droplets that trigger rain.
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The properties of angular noise of radar reflections from the rotor head are considered. On the basis of a multipoint geometric model of the rotor head, analytical expressions are obtained that allow ...calculating the parameters of the probability distribution density of angular noise for the azimuth planes and the elevation of the rotor head of a single-bladed screw at an undirected angle of the control sleeve. Correlation obtained for one blade rotor head is generalized to the case of a rotor head with an arbitrary number of blades. It is shown that the rotor head angular noise is a random process with periodically changing parameters. The theoretical results are confirmed by mathematical modeling.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Automatic control systems are created as optimality for the execution of the set operation. Change of operating conditions leads to loss of optimality. The self-configured (adaptive) systems are not ...always effective. They have the predetermined structure of a control algorithm. However, in new conditions it cannot meet the new requirements. The Intellectual Self-organizing Automatic Control Systems (ISACS) are capable to rebuild also structure of the control law. It is reached by the automated solution of a problem of synthesis of the control law. At creation of the interface of the developer of intellectual systems it is necessary to consider many factors, for example, ways of representation of knowledge, features of algorithms of processing of knowledge, etc. For development and the research ISACS the software "Modeling of Intellectual Self-organizing Automatic Control Systems" (MISACS) is created. This article is devoted to consideration of implementation in the MISACS system of the interface of the ISACS developer. The structures of representation of knowledge, elements of the mechanism of planning of actions on the basis of the artificial neural planning networks and the interface of the debugger of knowledge are presented.
The article deals with a new phenomenon for the legal science – the institute of legal regulation of the genesis of digital identity.The subject of the research is the relations that emerge in the ...process of such regulation. The aim of the research is to analyze the legal regulation of the institute of digital identity at the international, regional and national levels, including in the Russian Federation.The methodological basis of the research is the logical and systematic methods of scientific knowledge, as well as methods of analysis and synthesis, formal-dogmatic and comparative-legal methods.International, foreign and domestic experience in the genesis of digital identity is studied. The features of legal regulation of each of the elements of digital identity – digital profile, digital image, digital footprint – are analyzed. At the same time, the legal regulation of the relevant relations is considered in their dynamics. As a result of the study, conclusions were made about the peculiarities of international legal regulation of relations related to the genesis of a legal identity, the legal regulation of these relations in the European Union and China. It is noted that international legal regulation of relations related to the genesis of legal personality is carried out, as a rule, only in connection with the need to protect human rights and freedoms in the digital age, including in virtual space; in the European Union the legal regulation is mainly subject to the digital profile of the person, based on his personal data; at the level of individual states the most holistic and systemic regulation of relations related to digital identity is carried out in the People's Republic of China on the Special attention is given to the problems of legal regulation of the genesis of digital identity in the Russian Federation. It is noted that the problems of legal regulation of the genesis of digital identity are becoming particularly relevant at the present time. Its theoretical comprehension is a prerequisite for improving current legislation and law enforcement practice in the Russian Federation.It is pointed out that there are significant gaps in the legal regulation of relations related to the digital footprint in Russia, the most regulated relations in the area of digital profile and digital image; further lack of legal regulation of the collection and processing of information that constitutes the content of the digital identity footprint in Russia will lead to a massive violation of individual rights and freedoms.The study also found that the international legal regulation of relations related to the genesis of the legal personality is usually carried out only in connection with the need to protect human rights and freedoms in the digital age, including in virtual space, and in the European Union the legal regulation is mainly subject to the digital profile of the person, which is based on his personal data.
A mathematical model of joint servicing of priority real-time traffic and elastic data traffic in multiservice access nodes has been constructed and studied. Definitions of quality indicators for ...joint servicing of incoming requests for information services are provided. A system of statistical equilibrium equations is formed and its use for calculating the exact values of the introduced characteristics is considered. A method for approximate calculation of characteristics is proposed, based on the construction of a system of simplified equilibrium equations. It has been established that the obtained estimates of customer service indicators are asymptotically accurate in the region of large and small losses. The use of the developed method is shown to solve the problem of estimating the volume of traffic offloaded in an overload situation to other access nodes or to other frequency ranges in order to achieve values of specified QoS indicators and to solve the problem of planning the volume of required transmission resource of a multiservice access node.
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Bastnasite REE(CO3)F is the main mineral of REE ore deposits in carbonatites. Synthetic bastnasite-like compounds were precipitated from aqueous solutions by many different methods, but previous ...attempts to model magmatic crystallization of bastnasite from hydrous calciocarbonatite melts were unsuccessful. Here we present the first experimental evidence that bastnasite and two other REE carbonates, burbankite, and lukechangite, can crystallize from carbonatite melt in the synthetic system La(CO3)F-CaCO3-Na2CO3 at temperatures between 580 and 850°C and a pressure 100 MPa. The experiments on starting mixtures of reagent-grade CaCO3, Na2CO3, La2(CO3)3, and LaF3 were carried out in cold-seal rapid-quench pressure vessels. The studied system is an isobaric pseudoternary join of a quinary system where CO2 and fluorides act as independent components. Liquidus phases in the run products are calcite, nyerereite, Na carbonate, bastnasite, burbankite solid solution (Na,Ca)3(Ca,La)3(CO3)5, and lukechangite Na3La2(CO3)4F. Calcite and bastnasite form a eutectic in the boundary join La(CO3)F-CaCO3 at 780±20°C and 58 wt% La(CO3)F. Phase equilibria in the boundary join La(CO3)F-Na2CO3 are complicated by peritectic reaction between Ca-free end-member of burbankite solid solution petersenite (Pet) and lukechangite (Luk) with liquid (L): Na4La2(CO3)5(Pet) + NaF(L) = Na3La2(CO3)4F(LuK) + Na2CO3(Nc). The right-hand-side assemblage becomes stable below 600±20°C. In ternary mixtures, bastnasite (Bst), burbankite (Bur), and calcite (Cc) are involved in another peritectic reaction: 2La(CO3)F(Bst) + CaCO3(Cc) + 2Na2CO3(L) = Na2CaLa2(CO3)5(Bur) + 2NaF(L). Burbankite in equilibrium with calcite replaces bastnasite below 730±20°C. Stable solidus assemblages in the pseudoternary system are: basnasite-burbankite-fluorite-calcite, basnasite-burbankite-fluorite-lukechangite, bastnasite-burbankite-lukechangite, burbankite-lukechangite-nyerereitecalcite, and burbankite-lukechangite-nyerereite-natrite. Addition of 10 wt% Ca3(PO4)2 to one of the ternary mixtures resulted in massive crystallization of La-bearing apatite and monazite and complete disappearance of bastnasite and burbankite. Our results confirm that REE-bearing phosphates are much more stable than carbonates and fluorocarbonates. Therefore, primary crystallization of the latter from common carbonatite magmas is unlikely. Possible exceptions are carbonatites at Mountain Pass that are characterized by very low P2O5 concentrations (usually at or below 0.5 wt%) and extremely high REE contents in the order of a few weight percent or more. In other carbonatites, bastnasite and burbankite probably crystallized from highly concentrated alkaline carbonate-chloride brines that were found in melt inclusions and are thought to be responsible for widespread fenitization around carbonatite bodies.
Control system design for complex technical plants includes execution of computationally complicated procedure sets. Many of those demand repeated iterative execution. Iterations are caused by ...uncertainty of a control task, incompleteness of the information on control plant and conditions of its functioning. Another important reason is related to insufficiently perfect methods of the automatic control theory, because of its ongoing active development. Therefore, the task of developing the computer-aided control system design is as relevant as before. The publication is devoted to the statement of an approach to expansion of GAMMA-3 multipurpose system opportunities. An important feature of GAMMA-3 system includes opportunities for solving the tasks via both traditionally procedural and non-procedural statements. At the first stage, the proposed approach provides the expansion of classes of procedural task statements as the most formalized process. At the following stage, formalization and generalization of saved procedural knowledge in new expanded model of the subject domain takes place. The domain in question allows for non-procedural task statement. Solving non-procedural declared tasks requires using intellectual components of GAMMA-3 system. In this paper, we illustrate the first stage of the proposed approach on the example of creating GAMMA-3 software package for solving the problems on the synthesis of a control system by modeling UAV movement on defined trajectory. One of the main tasks conducted by UAV is surveying remote areas, where data acquisition by habitual ways is complicated or there is a danger to lives and health of the people.
The mechanisms of intragrain plastic deformation occurring in local micro-volumes of metal under the influence of temperature stresses during high-speed heating due to high-energy exposure are ...studied. The temperature distribution over the thickness of the sample is calculated and its experimental verification is carried out. Samples of steel 12Cr18Ni10, which does not undergo phase transformations during heating and cooling, are examined after a treatment with scanning air-plasma arc. It is shown that the intragrain plastic deformation during heating of austenitic steel is caused by thermoelastic stresses arising in the heated layer and in the volumes bordering it and manifests itself in the appearance of sliding traces in the grains. The mechanisms of the appearance of temperature stresses in the metal are proposed and substantiated.
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We construct and study a mathematical model for the distribution of information transmission resource in a multiservice access node. The model considers an arbitrary number of multimedia traffic ...streams, which differ in the intensity of claims arrival, the amount of resource used to service one claim, and the resource occupation time. The time intervals between the arrival of claims have an exponential distribution with a parameter depending on the number of claims being serviced in the considered flow. We construct a recursive algorithm for evaluating the characteristics. Relations are established between the integral and flow characteristics of the quality of service for the claims. We construct an efficient algorithm for estimating the amount of resource required to service given traffic flows with required quality. The efficiency of the computational procedure is achieved as a result of organizing recursion over the volume of resource and the use of normalized values of state probabilities. We consider a solution to the problem of estimating the required amount of resource for a multiservice node model, which allows to use resource reservation and dynamic distribution mechanisms when servicing elastic traffic. We show numerical examples that illustrate the features of the implementation of the constructed computational procedures.
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Microarc surface alloying of steel is performed in carbon powder under electric current flow conditions, which leads to accelerated surface material impregnation with carbon. For surface impregnation ...with other alloying elements, a coating containing a diffusion agent is used, which is previously applied to a strengthened component. The purpose of this work is a study the effect of microarc diffusion impregnation temperature of steel with boron combined with carbide-forming elements on coating structure, phase composition and microhardness. Cylindrical steel 20 specimens are subjected to multicomponent impregnation with B + Cr, B + Mo, B + V, B + W at 950, 1100 and 1250 °C. Duration of the impregnation process is varied from 2 to 8 min. A coating containing boric acid H
3
BO
3
powder and ferroalloy powders of carbide-forming elements in a ratio of 1:1 by volume based upon an electrically conductive binder is used for alloying. It is found that after microarc multicomponent impregnation at 950 and 1100 °C a diffusion layer consists of a base in the form of a fine ferrite-carbide mixture with microhardness up to 9.4 GPa, within which there are high hardness finely dispersed inclusions of iron and carbide-forming element carbides and borides having a higher microhardness (up to 16.5 GPa) compared with single-component boriding. Then there is a carburized layer with a eutectoid structure, passing into the original ferrite-pearlite structure of steel 20. After multicomponent impregnation at 1250 °C a diffusion layer additionally contains sections of carbide forming eutectic existing within the Fe–C–B system, with an increased content of chromium and boron as a result of predominant diffusion along grain boundaries. Therefore, microarc surface impregnation of steel with boron combined with a carbide-forming elements increases the temperature of boride eutectic formation, which may lead to increased layer brittleness compared with single-component boriding. The greatest diffusion layer thickness is obtained after 6 min of the microarc multicomponent impregnation process and then it hardly increases due to carbon particle combustion and depletion of the diffusion agent source within a coating.
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