CONFORMITIES TO LAW OF FORMING LAYER FOR POLYDISPERSE PELLET CHARGE ON SINTER BELT

Motion of pellet charge on the loading tray on a sinter belt is accompanied not only by the change of its grain-size composition, but by segregation processes, id est. by the redistribution of charge of different size particles for the most part friable material. The result of this process is formation of local discontinuity with pre-dominance of content for particles of certain factions. The traditional method for analysis of work for loading tray on the basis of factious classification does not allow to educe and analyze appearing heterogeneity in the most part friable material. It results in errors at the calculation for action of the system of the automated control by sintering process and ignoring of notational of the use of segregation of particles of friable material for optimization of technological process. The use of balance method enables to specify and spread understanding of mechanism of processes which take place during motion of pellet charge in relation to the loading tray, and also to form theoretical pre-conditions for the choice of the rational modes of operations of agglomeration separation of sintering plant. It is set that at monotonous increase of angle of slope for loading tray the segregation phenomena increase in a pellet charge, and after achievement of the defined value – go down, id est. have extreme character. Mentioned features of forming of layer for polydisperse material in the conditions of inconstancy of mechanical properties of its separate factions it is possible to take into account at the use of balance of grain-size composition of charge, loaded on a sinter belt, and charge, being on it, when conditional middle diameters of particles of their components must be equal. On the basis of the set conformities to law of forming of friable of structure of layer the method of authentication of grain-size compositions of pellet charge mixture is in theory reasonable in every its horizon taking into account a segregation during loading.

An Effect of Fillers on the Structure and Abrasive Wear of Polyurethane Urea

The introduction of small amounts of calcium stearate and molybdenum disulfide into polyurethane ureas based on a oligoether of polyoxytetramethylenediol with a molecular weight M~1000 does not lead to a significant change in the abrasive wear mechanism of the polymer material. The concentration dependence of the wear degree on the filler content has an extreme character, which is associated with the different direction of the filler effect on the cohesive and frictional properties of the studied material.

UNIVERSAL METHOD FOR COMPUTATIONAL MODELING OF THRESHOLD PHENOMENON IN THE NONSTEADY BIOLOGICAL PROCESSES

Context. In modern conditions occur abrupt changes in ecosystems. The species composition of Caspian Sea is changing rapidly. The dynamics of populations acquires an extreme character with the development of rapid invasions. The mathematical description of scale transformations requires new modeling methods. Complicated population regimes of changes have features of the threshold phenomenon in process of its development. Objective. We set the goal of computational modeling of practically important scenarios – groups of situations that relate to extreme and transitional dynamics of ecosystems, like outbreaks at the onset of dangerous invasions. We are developing a method that, on the basis of the survival model of generations, will conduct a description of sudden transitions to rapid but limited outbreak of numbers or, on contrary, a collapse of stocks like Atlantic cod in 1992 or Peruan anchovy Engraulis ringens in 1985. The purpose of our modeling is to improve the accuracy of forecasts of the population size when experts are estimates a rational strategy for the exploitation of biological resources. Method. Situations of abrupt but short-term changes in population processes cannot be calculated by traditional mathematical models and expressed in terms of asymptotic dynamics – closed limit trajectory sets. The basis of the idea of the method proposed by us is the formalization of nonlinear efficiency of reproduction, which changes in a threshold manner only in strictly defined environmental conditions. We use continuous-discrete time in the model for early ontognosis of the cod fish and insect pests. The method with triggers allows us to take into account in simulation experiments logic and motivation of making decisions by experts, people who manage the strategy of exploiting biological resources. Models assess variability for development of situations Results. We have implemented new method of bounded trigger functionals into hybrid system of the equations, that acting in selected specific states of biosystems. Analysis of new model scenarios with modifications of functionals in the basic hybrid system for extreme situations in fish and insect pests is carried out. Conclusions. We consider the method to be universal, since selection of the functional can be adapted to a wide class of models using differential equations on a fixed interval.

Mathematical Model of Tubular Linear Induction Motor

Problem of calculation of distribution of magnetic field induction in clearance of tubular linear induction motor (TLIM) is considered. Mathematical model is represented by Fredholm integral equations of second kind for complexes of electric field strength and density of coupled magnetization currents at interface of environments. Algorithm of calculation of distribution of magnetic field induction in TLIM clearance has been developed. Dependence of magnetic field induction in motor clearance on value of pole division is investigated. There is area of optimum pole pitch. Reliability of results of calculations on mathematical model is confirmed by their comparison with results obtained on physical model. Calculated dependence of induction on thickness of runner's iron circuit also has extreme character. Given model can be used at design stage of TLIM. Model allows calculating its optimal geometric dimensions based on criterion of maximum induction in motor clearance, taking into account physical properties of applied materials.

Adhesion-strength and tribotechnical properties of machine-building composite polymer coatings

The article presents the results of studies of adhesive, strength and tribotechnical properties of composite polycaproamide polymer materials and coatings based on them for mechanical engineering purposes. It has been established that the relative change in the adhesion strength depends on the degree of filling in air and in argon has an extreme character passing through a maximum for coatings based on PCA with aluminum oxide, and for coatings made of PCA with copper oxide, it has a complex character. The formation of adhesive, strength, and tribotechnical properties of filled polycaproamide coatings was also studied. At the same time, it was found that by adjusting the temperature-time technological modes, it is possible to increase the adhesive, strength, and tribotechnical characteristics of composite polycaproamide coatings for machine-building purposes.

Влияние структурно-морфологических характеристик на сенсорные свойства пленок Cd-=SUB=-x-=/SUB=-Pb-=SUB=-1-x-=/SUB=-S

Polycrystalline films of CdxPb1−x S (0.021 ≤ x ≤ 0.090) supersaturated substitutional solid solutions with a cubic structure B1 (Fm3¯m space group) have been obtained with varying cadmium acetate salt Cd(CH3COO)2 in the reaction mixture within 0.01−0.1 mol/l on the sitall substrates. Their thickness changed from ∼ 0.4 to ∼ 1.0 microns. A correlation has been established between the structural-morphological and functional properties of CdxPb1−x S thin-film layers. The extreme character of the voltage sensitivity dependence on the cadmium salt concentration in the reaction bath is associated with the nonmonotonic introduction of cadmium into the PbS crystal lattice. It is shown that the maximum photocurrent is possessed by CdxPb1−x S thin-film layers formed from crystallites with pronounced faceting. We have found the surface sensitivity of the CdxPb1−xS films to the presence of ∼ 0.02 mg/m3 NO2 in the air, which is significantly lower than the maximum allowable concentration.

Структурные и электрофизические свойства пленок PbS, легированных Cr-=SUP=-3+-=/SUP=- в процессе химического осаждения

The evolution of the morphology, composition, structural characteristics (lattice constant, microstrains, texturing), optical and photoelectric properties of the PbS films obtained by chemical bath deposition in the presence of ammonium iodide and chromium (III) chloride at a concentration of up to 0.02 M has been studied. According to the elemental analysis by an energy dispersive X-ray spectroscopy, the chromium content in the PbS films has a nonmonotonic dependence on the CrCl3 concentration, and the largest amount is 1.08 at%. The particle size distribution is monomodal, and the average size of the particles forming the films varies from ~ 100 to ~ 225 nm with a content of 2–6% of nanoparticles. The introduction of NH4I and CrCl3 into the reactor preserves the cubic B1 structure of lead sulfide and results in an increase in the band gap Eg by 0.16–0.20 eV, a decrease in the dark resistance Rd, and an increase in the voltage sensitivity Us. The dependences of Eg and Us on the concentration of the chromium salt in the reaction bath have an extreme character with a maximum at 0.016 M, which is associated with the nonmonotonic incorporation of chromium into the PbS lattice. The results of studying the current-voltage characteristics of thin-film PbS(I) and PbS(I, Cr) layers are in good agreement with the results of the structural, optical, and photosensitive properties.

MOBILIZATION POTENTIAL OF THE VIRTUAL NETWORK SPACE

The article analyzes the mechanisms of deploying mobilization processes in the virtual space of the Internet: the features of these processes are considered, models of distribution of mobilization content are highlighted, and techniques and tools of network mobilization are characterized. Mobilization processes online are characterized by a high degree of anonymity, the complexity of countering them, as well as low predictability of occurrence and development. Considering the problem of mobilization messages’ impact effectiveness on various types of target audiences, the special importance of the content of these messages, and above all, its characteristics such as extremeness, extraordinary nature, extreme character of information messages, is emphasized. A special place in the process of transmitting information is occupied by the virality of content – the possibility of replicating posts by users, which allows stimulating community members to unite. From the point of view of semantic content, it is advisable to consider mobilization content through the prism of a cognitive scheme – a key element of the frame, a kind of template through which a person receives and comprehends information: once in a similar situation, people act according to an already formed scheme. Mobilization messages in the context of cognitive schemes can have different variants; however, the analysis allows us to identify their universal components: the enemy, whose image is demonized; actions that need to be performed; forces that must unite to perform actions. One of the most urgent problems in the subject field of political mobilization is the communicative models for the dissemination of mobilization messages in online media. It is the study of the information transmission processes that allows us to identify the most effective methods and tools of influence. At the same time, recently, the trend of politicizing absolutely any virtual platforms and online tools that were not originally intended for mobilization purposes has become obvious.

MAGNETOCALORIC EFFECT AND HEAT CAPACITY OF MAGNETIC FLUIDS

The magnetic fluids based on magnetite nanoparticles were synthesized using mixed surfactants (oleic acid/alkenyl succinic anhydride) dispersed in different carrier media (polyethylsiloxane and dialkyldiphenyl). The physicochemical properties of magnetic fluids (density, viscosity, saturation magnetization, magnetic phase concentration, magnetic core size) were determined. Magnetic fluids are stable in a wide temperature range. All the samples of the magnetic fluids exhibit typical superparamagnetic behavior. The magnetocaloric effect and the specific heat capacity of the magnetic fluids were first direct determined at 288–350 K in a magnetic field of 0–1.0 T. The field dependences of the magnetocaloric effect have a classic linear form. The temperature dependences of the magnetocaloric effect of magnetic fluids in magnetic fields have an extreme character. Thermodynamic parameters of magnetic fluids (magnetization namely enthalpy/entropy change) were determined. The specific heat capacity of magnetic fluid samples in a zero magnetic field was obtained at different temperatures (at 278–350 K) on a differential scanning calorimeter and on the original microcalorimeter. The temperature dependences of the heat capacity of magnetic fluids in magnetic fields have an extreme character. It was established that the difference in heat capacity values obtained in and without the magnetic field is within the experimental error. The extreme character of the heat capacity is reflected in the magnetocaloric effect temperature dependences.