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Spectral features of the original and irradiated with electrons with E = 2 MeV GaP light emitting diodes (LEDs) were studied. Recombination lines of the exciton bound on the N isoelectronic center and on the pair complexes NN1 were detected. The change in the spectral composition of radiation when passing through a section of negative differential resistance is analyzed. Dose dependences of luminescence intensity were obtained for green GaP(N) and red GaP(Zn-O) LEDs. The maximum critical radiation dose was established, after which the LEDs lost their characteristic exciton emission mechanism. The results of the annealing of irradiated LEDs are given.

Relevance. Modern approach to development of oil and gas fields. Digitalization and automation of hydrocarbon production allow not only to reducing the response time to possible deviations from the operating level of production, but also quickly making decisions on its further normalization. The use of modern software to create a reservoir model using the material balance method allows you to calculate current and predicted reservoir pressures depending on the amount of selected and injected fluid. With high-quality adaptation, the integration of the reservoir model, wells and collection system, in its turn, allows you to correctly approach the choice of a field development system, as well as correctly assess the possible potential of the field. Forecast calculations performed on an integrated model can form the basis for budget planning, as well as the basis for carrying out geological and technical activities on wells, commissioning new wells, and modernizing equipment and infrastructure. Moreover, group optimization calculation allows us to maximize additional oil production, taking into account all geological and technical constraints. Aim. Formation and analysis of an approach to setting up a reservoir model by adapting parameters using the material balance method; formation of a solution for adapting the integrated model, reconciliation of the results with actual data; carrying out an optimization calculation and obtaining additional oil production. Methods. Adjustment and adaptation of reservoir models using the material balance method; adjustment and adaptation of the integrated model of a field/group of fields; calculation of the forecast for a period of 30/90 days; optimization calculations. Results. The obtained results make it possible to adapt the components of the integrated model with an accuracy of ±5 %, which makes it possible to simulate the operating mode of the field. As a result of the analysis, tuning criteria were identified, and the minimum required set of parameters for a qualitative adaptation of the reservoir model and the collection system was presented. The effectiveness and accuracy of the tool are also proven by comparing actual data on operating modes with synthetic ones. Based on the work done, it can be concluded that the use of the integrated model shows us a high convergence with real data, which allows us to optimally approach the field development mode. Moreover, an optimization calculation was carried out to obtain additional oil production using the proposed solution, and a forecast for oil production for a period of 90 days was calculated, which was later confirmed when compared with actual data.

Introduction. One of basic technological operations in construction technology is a process of classification of fine grained mineral materials, for example, natural sand. The related actual problem is connected with increasing performance and effectiveness of screening of sand medium, in particular reducing the contamination of screening surface of vibrating screens from seal particles and sticking in sieve holes wedge-shaped grains. The solution of this problem concludes in performing by the use of vibroimpact screens of various operating principle. One of innovative vibroimpact screen constructions is a screen with vibroimpact lattice, mounted under sieve with a gap on spring elements, which provides an impulse impact on all sieve surface area. Such construction provides increasing the effectiveness of sieve cleaning due to the transfer to sieve impact impulse in each screen oscillation period and reducing its excessive damage and abrasion by increasing the area of vibroimpact lattice and sieve interaction. The purpose of the work is to determinate functional relationships of dynamical interaction between elements of three-mass vibroimpact ‘screen body – vibroimpact lattice – sieve’ system for providing the necessary value of impact impulse transferred to sieve in relation to screen body oscillation frequency and amount of gap between lattice and sieve.Materials and methods. The research is based on a method of mathematical modelling. On the first stage the research is being conducted with using two-mass ‘screen body – vibroimpact lattice’ model without consideration the impact between lattice and sieve for determination the oscillation frequency range of in-phase oscillation regime and gap values providing an impact between lattice and sieve. For the calculation of displacement of screen elements and for research the relationships of its parameters in selected range the three-mass model of vibroimpact model of screen with one impact pair is used on a second stage of research.Results. As a result of calculation obtained the functional relationships of correlation of the gap between vibroimpact lattice and screen sieve and oscillation frequency on the impact impulse transferred to sieve and sieve double amplitude were obtained. The developed recommendations for practical using of obtained relationships for adjustment operating regimes of vibroimpact screen which allow to establish the screen operating oscillation frequency and value of gap between lattice and sieve for providing high effectiveness of sieve holes cleaning from contaminating particles.Discussion and Conclusions. Performed mathematical modelling allowed to obtain dependencies of influence of gap between sieve and vibroimpact lattice and screen elements oscillation frequency on impulse transferred on screen sieve and sieve double amplitude. Developed practical recommendations of obtained dependencies allow to perform an effective adjustment of vibroimpact screen operating regimes and reduce the labor intensity of works being performed during its starting-up and maintenance.

A study was conducted to determine the level of knowledge and factors influencing awareness of Good Agriculture Practices among mandarin growers in Jajarkot, Nepal. For data collection, 60 commercial mandarin producers were interviewed using pre-tested semi-structured questionnaires. Based on their knowledge of GAP, the farmers were divided into two groups: GAP aware and GAP unaware. The data were analyzed using statistical tools such as binary logistic regression, t-test, and chi-square test. The results revealed that less than half of the respondents were aware of the Mandarin GAP. GAP linked to waste management was embraced by the majority of respondents, whereas GAP related to documents and records was determined to be the least adopted of the 10 standards. The t-test result showed a significant difference in dependency ratio between GAP aware and GAP unaware respondents. Similarly, number of bearing trees was significantly different between GAP aware and GAP unaware respondents. The Chi-square test revealed that training had a significant relationship with GAP awareness. The binary logit model's result indicated that education level and experience in mandarin farming have a substantial impact on GAP awareness. Lack of plantation material, followed by illness and insects, a lack of knowledge of new production techniques, lower productivity, a lack of subsidies, and a lack of insurance were the main production issues. Hence, subsidies and crop insurance must be provided to the farmers and GAP awareness programs and training are required to boost mandarin output.

The homo-transitional original and irradiated by electrons with E = 2 MeV; F = 5.9⋅1014 cm-2 ÷ 8.2⋅1016 cm-2 GaP LEDs were studied. The effect of radiation treatment on their electrical and optical characteristics was studied; the results of isochronous annealing of irradiated samples are given; the consequences of high-temperature annealing of output diodes are analyzed. Peculiarities of the formation of the current-voltage characteristics of red LEDs doped with Zn, O, and green LEDs doped with N under reverse bias, as well as features of the recovery of the reverse current during annealing of both types of LEDs, are revealed.

Heterostructures with lattice mismatched and compositionally different layers are widely used in modern electronic and optoelectronic device engineering. Generally such structures are manufactured by the methods of metal-organic vapor phase epitaxy, metal-organic chemical vapor deposition and molecular-beam epitaxy. However, the methods of deposition from a liquid phase are the most inexpensive and simple yet. Thus obtaining the above mentioned heterostructures from a liquid phase is still promising. In this work we demonstrated the possibility of using the method of scanning liquid phase epitaxy to grow continuous heteroepitaxial layers over the substrate surface highly mismatched by lattice constant and having different crystal-chemical properties. By controlling basic parameters of the method we created the conditions close to the solution-melt saturation limit. In other words, we created the conditions of ultra-fast solution-melt cooling and, respectively, high growth rate. We obtained the heterostructures of Ge layers grown on GaP substrates where the lattice mismatch made 3.7%. Gallium was used as the solvent for Germanium. The heterostructure was grown by the method of scanning liquid phase epitaxy in the conditions of ultra-fast initial cooling of the solution-melt. Overcooling at the crystallization front was controlled by an extra heater of the substrate back side. The growing time was 1 and 20 seconds for the two test samples. The layers thickness was determined by the spherical slice technique to be 1.2 and 1.5 μm for these two growing time values, accordingly. We showed that it was possible to obtain more perfect Ge layers on GaP substrate by lowering the growth rate in the final growth stage. This method can be used to grow heterostructures used in creating such modern electronic and optoelectronic devices as structures based on A3B5 compounds and their solid solutions, which cannot be obtained by other classical methods of liquid phase epitaxy due to significant differences in lattice constants and / or crystal-chemical properties.

When making welded joints, it is not always possible to press tightly elements to be joined before surfacing the weld. In normative documents on welded joints, the allowable gap between the elements to be connected can reach 3 mm when welding with a covered electrode and 2 mm when welding in shielded gases. At the same time the presence of a gap is not taken into account in the standards for calculation of welded joints. Experimental studies have been carried out to determine effect of the gap on the bearing capacity of the weld. Specimens have been made with welded joints of two types: for work in shear and pull-out. For the purpose of comparison, half of the specimens have been made without gaps, and the other half with gaps between the elements to be joined. The specimens have been made at the Minsk plant of technological metal structures, and their tests have been carried out in a research laboratory of the Belarusian National Technical University. Based on the results of the experiments, it has been concluded that the gaps between the elements to be joined significantly reduce the bearing capacity of the welded joints. In addition, inspection of fracture surfaces have shown that, in the presence of a gap, the cut surfaces of the weld pass along the fusion boundary of the base and deposited metals. It has been experimenttally established that the existing gap leads to a slight increase in the penetration depth. However, the latter factor does not compensate for the decrease in the bearing capacity of the welded joint due to the presence of a gap between the elements to be joined.

Nowadays the improvement of the design of liquid-propellant rocket engines (LPREs) depends on a variety of factors and activities, among which we can distinguish, for example, the improvement of energy characteristics of units and assemblies forming part of the LPREs. The article compares the operation of LPRE turbo-pump turbines using double-sided and single-sided labyrinth seals used in Energomash's engines. The key geometrical parameters of each seal variant, images of 3D-models of seals constructed for the calculations, the resulting computational grid for each seal variant, as well as graphs of the pressure distribution and velocity fields are presented for visual comparison. Sectoral leakage was calculated for each variant of the seal, the possibility of reducing the temperature of the turbine inlet working gas was assessed. In the future attention should be paid to a more detailed study of this type of seals with the use of modern computing power

In modern mobile power tools of domestic and foreign production, the torque from the engine to the working mechanisms is transferred, as a rule, by hydrostatic drives consisting of regulated and unregulated axial-plunger hydrounits. Their technical condition directly affects the performance of machinery in general. The analysis of the operability and longevity of controlled axial-plunger hydraulic units showed that in the pre-repair operation period the share of their failures is about 20 % of the total number of machine failures. According to scientific and technical sources, the average overhaul life of the repaired controlled axial-plunger hydrounits of the 313.3 series under actual operation does not exceed 60 % of the resource of the new product. The most vulnerable hydraulic drive units are the axial-plunger motor and pump, which include precision parts and make up more than 90 % of the cost of the entire drive. If the hydraulic drive fails and the malfunction can not be repaired directly in the operating conditions, the above mentioned units are sent to specialized enterprises for repair. Usually, because of the lack of diagnostic equipment, both at the operator enterprises and at repair enterprises both units are sent for repair without preliminary diagnosis. Repair companies explain the need to send both of units for repair as they have the same residual life. The results of our studies show the absence of such a pattern. At the repair enterprises, the repair is not carried out for the same reason — the lack of diagnostic equipment. Due to this, the two units sent for repair are subjected to complete disassembly, defects identification and repair. The available research results show that in more than 40 % of cases, the units require no repair. The purpose of the work is to develop a stand and a method for assessing the technical condition of hydraulic power units for mobile power equipment, to increase the functional reliability and efficiency of maintenance, to prevent failures during operation of the hydraulic drive and to ensure the prediction of the residual life of aggregates at specified operating intervals.

The article deals with the phenomenon of gaps in legal terminology of the English language from the point of view of its Russian translation. The author analyzes the approaches to understanding lexical gaps. Examples of terminological gaps have been selected from English-English explanatory dictionaries. The selected terminological units have no equivalents in legal terminology of the Russian language. The study reveals the role of the commentary in rendering the meaning of terminological gaps. While considering the factors determining the existence of gaps, the author pays attention to both linguistic and extra-linguistic factors. The research revealed a number of lexical gaps among the terms of international law. English-Russian termninological dictionaries in some cases contain the explanations of notional gaps. The use of transliteration is a signal of notional gap. The conclusion is made about the connection between the perception of gaps and the structures of one’s mother tongue. The social and historical character of the gaps under study has been proved to be well-grounded. The author emphasizes the importance of detailed definitions for adequate rendering of the gaps.

It is stated results of control in the course of repair of technical condition of cylinders of engines. Need of diagnosing of cylinders in structural parameters by direct measurements with partial or full dismantling of engines is proved. The description of an order of performance of direct measurements of cylinders, the formed wear forms, possible errors of a relative positioning of surfaces and axes of details of tsilindroporshnevy group, a crank – the conrod mechanism and their influence on process of wear of cylinders is made.

Copyright of Technical Electrodynamics / Tekhnichna Elektrodynamika is the property of National Academy of Sciences of Ukraine, Institute of Electrodynamics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the Pleasure of the text (1973) Roland Barthes makes an extensive use of psychoanalytic concepts and it allows him to talk about text, writer, writing, readers and critics. Roland Barthes says little about desire, although in psychoanalysis it is closely linked to the notion of jouissance and pleasure. The main question to be examined in the given article is the following: What does psychoanalytic optics means for Roland Barthes in his reflections on the Text? Several key concepts of his writing are to be analyzed, namely: jouissance (enjoyment), pleasure, perversion, fetishism, gap. [ABSTRACT FROM AUTHOR]

The article considers regularities of the influence of forces of viscous resistance generated by the damper device in the cylindrical hinges of the nodes connect the links of the crane-manipulator units mobile transport-technological ma-chines. The specified effect is considered on the efficiency of the damping of oscillations of the metal in the process of operation, due to the presence of increased clearances due to wear of the holes of the hinge eyes. It is shown that the force of viscous resistance should be considered in addition to the generated damping devices forces of elastic resis-tance, as the latter determine the effectiveness of damping in general. The main role of forces of viscous resistance is the dissipation of energy of an oscillatory turning movement of the mating parts of the metal structures due to oscilla-tory displacement of the hinge pin within the hinge gap until the complete decay of oscillations. Considered in relation to the crane-manipulator installing mobile transport-technological machines AST-4-A the effect of the action of forces of viscous resistance is almost not observed when the coefficient of viscous damping less than 0.01 MN∙s/m, in the range 0,01...0,05 MN∙s/m this influence begins to manifest itself more and more noticeable, in the range of 0,05...0,4 MN∙s/m has a lot of damping vibrational displacement of the hinge pin within the gap, while the coefficient of viscous damping more than 0.4 MN∙s/m oscillatory process becomes aperiodic with an almost complete attenuation in the range of one oscillation of the hinged finger.

The article considers the problems of designing an original damping devices worn for cylindrical hinges in crane-manipulating installations of mobile machines. These devices can significantly reduce the additional impact load on a steel structure manipulators due to the presence of increased gaps in the hinges. Formulated the general formulation of nonlinear constrained optimization of the sizes of the elastic elements of the damping devices. Considered a promising design variants of elastic elements. For circular and arc elastic elements with circular and rectangular cross-section for-mulated the problems of optimal design including criterion functions and systems of geometric, technological, stiffness and strength penalty constraints. Analysis of the impact of various operating and design parameters on the results of optimal design of elastic elements was performed. Were set to the recommended the use of the constructive types of elastic elements to generate the required stiffness of the damper devices.

Subject of Research.The paper deals with questions of operation safety for continuous welded rail track under dynamic loads. We study the gap value formed in the rail bar in view of its possible break under the conditions of dynamic loads caused by the moving train and varying temperatures. Occurring strains are linked to a variable stiffness of the rail track base (ballast). Methods. We studied longitudinal oscillations in a semi-infinite rod under dynamic loads and in the process of thermal expansion of the finite length rod on the elastic-damped foundation. Oscillatory processes in a semi-infinite rod on an elastic foundation was modeled using the extended equation of longitudinal vibrations, taking into account the reaction of the foundation, performing the role of a damper. To determine the state of the model after the damping of oscillations we used the time limiting transition. In solving the problem of thermal expansion of the finite length rod on the elastic foundation we used equilibrium equation for small fragment, which takes into account the thermal load and the elastic force of both the rod and the foundation. Main Results. We have calculated the maximum value of the dynamic displacement of the rod end at different values of parameters. We have obtained the distributions of stresses and displacements along the rod length for different stiffness distribution in the elastic foundation. In the event of accidental break in the rail, the gap value after the damping of oscillations is set at the level of 5-7 cm. We have shown that the amplitude of these oscillations can reach 10-12 cm. The availability of limited stiffness change zones in the rail base causes no significant deformation of rail bars, but can lead to the growth of the gap in the rail bar break. Practical Relevance. The proposed model can be used in the calculation and design of continuous welded rail tracks.

The article was the analysis of dynamic processes in the cylindrical hinges with large gaps in the cargo boom crane-manipulating installations of mobile machines in operation. Consider the design of damping device for articulated joints, which creates a braking force of elastic resistance to the displacement of the hinge pin within the large gap. The mechanism of action of the damping devices was considered. Analysis of the effectiveness of damping device for re-ducing the dynamic stress state in the elements of cargo boom metal structures depending on the gap size and the stiff-ness of the damping device was performed. Damping device with an elastic shock absorbing elements substantially reduces the additional impact load at the time of selection of the gap in the joint, slow the growth of clearance in the pivot joint, limit the size of the gap specified value, which must not be exceeded during the entire service life of swivel independently from the intensity of his load.

Results of reverse electrophysical characteristics study of red and green LEDs, initial and irradiated with 2 MeV electrons were given. It was found that reverse current was predominantly caused by carriers tunneling at Urev ≤ 9 V, and by the avalanche multiplication at Urev ≥ 13 V, in the range U = 9 ÷ 13 V both mechanisms are available. Current increase at high voltage areas (Urev > 19 V) is limited by the base resistance of diode. In the case of significant reverse currents (I > 1 mA) irradiation of diodes leads to the shift of reverse current-voltage characteristics into the high voltages direction.

Copyright of Mohyla Mathematical Journal / Могилянський математичний журнал is the property of National University of Kyiv-Mohyla Academy, Faculty of Humanities and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Almost simple {SM}_m -groups are considered. A group G is called {SM}_m -group if the tensor square of any irreducible representation is decomposed into the sum of all characters with multiplicities not greater than m. It turned out that if G is an almost simple {SM}_2 -group, then G congruence {PGL}_2(q).

Almost simple SM_m-groups are considered. A group G is called a SM_m-group if the tensor square of any irreducible representation is decomposed into the sum of its irreducible representations with multiplicities not greater than m. In the first part of this article we consider simple groups. It turned out that among them only groups L_2(q), q = 2^t, t > 1, are SM_2-groups.

The method of reception of p+–n-diode epitaxial structures of GaP from liquid phase is developed. In the temperature range of 80—520 K thermometric and current-voltage characteristics of test models of diode temperature sensors are measured and their basic technical parameters are determined. Perspectivity of developed GaP-diodes application as sensitive elements of high-temperature sensor is shown.

Aim. To examine electrophysiological characteristics of the phenomenon of the atrioventricular curve gap (ACG) in patients with metabolic syndrome (MS). Material and methods. The study included patients aged over 15 years with ACG. Electrophysiological characteristics of this phenomenon were compared in 55 patients with MS (by NCEP ATP III 2001 criteria) and 47 free of MS. Patients with coronary heart disease and/or diabetes mellitus were not included. Results. MS was associated with increased gaps and their duration. Gap distribution by the curve in MS-free patients was extreme. Most gaps occurred in the zone close to effective refractory period of atrioventricular connection. In MS this phenomenon occurred along the whole curve. Conclusion. MS influences characteristics of ACG. This must be taken into consideration in conduction of electrophysiological test.