Analysis of the influence of warming on the quality of soldered instruments

The study is focused on the analysis of the influence of short-term exposure to high temperature on tungstenless hard alloy metal plates while soldering iron-carbon. According to dness deviation amounted to( + -) 3%

Methodology of strength calculation under alternating stresses using the diagram of limiting amplitudes

The work proposes the algorithm to calculate strength under alternating stresses using the developed methodology of building the diagram of limiting stresses. The overall safety factor is defined by the suggested formula. Strength calculations of components working under alternating stresses in the great majority of cases are conducted as the checking ones. It is primarily explained by the fact that the overall fatigue strength reduction factor can only be chosen approximately during the component design as the engineer at this stage of work has just the approximate idea on the component size and shape

Lending system for agricultural enterprises: Prospects for development and transformation

The article examines the current situation of using lending, leasing and factoring instruments for agricultural producers in modern Russia. The authors note that the current lending and leasing system requires transformation to take into account the conditions for the activities of agricultural enterprises, taking into account seasonality and the delayed effect of obtaining results. A transformation system for leasing is also proposed to make the instrument more flexible through the introduction of commercial instruments and the abandonment of exclusively government regulation of the activity in question. The authors note the effectiveness of the transformation of the proposed methods of lending, leasing and factoring by increasing demand and reducing the risk of repayment for both enterprises and participants in the banking sector

The necessity and complexity of standardization

-The standards are one of the most important infrastructural elements of the economy. The relationship between all factors ensuring product quality and safety is carried out by using complex standardization. The standards establish and ensure the technically achievable level of safety, quality and competitiveness of products. The main factors of standardization object: the object composition, object production and monitoring, in their turn, form the following more precise groups of factors, determining the object quality: primary products and materials, component nodes and parts, production technology, equipment, tools and appliances, measurement means, and test methods. On the example of a specific standard, the "tree of references" of the first and second levels and the problems of an integrated approach for establishing quality requirements for a specific product is considered. The necessity and complexity of updating the requirements that ensure the systematization, optimization and coordination of all interacting factors influencing a specific object of standardization and providing an economically optimal level of quality of the object are demonstrated. © 2020, World Scientific and Engineering Academy and Society. All rights reserved

Melatonin and its regulatory effect on the hormone, tissue and cellular levels

Проведен анализ ряда работ отечественной и зарубежной литературы, посвященных изучению регуляторного влияния мелатонина на организм. Показана возрастная динамика синтеза мелатонина, определенные механизмы влияния на репродуктивную функцию, антиоксидантные и иммуномодулирующие свойства, участие в процессах канцерогенеза, посредством изменения пролиферативной и апоптозной активности, угнетения активности теломеразы. В результате проведенного анализа можно заключить наличие у мелатонина способности регулировать биологические ритмы, антиоксидантной и противоопухолевой активности, контроля над эндокринной, нервной, иммунной системами, способности обеспечивать естественную структуру сна, замедлять процессы старения, влияния на развитие беременности и плод.The analysis of a number of works of domestic and foreign literature devoted to the study of regulatory impact on melatonin hormone, tissue and cellular levels. Has been shown age dynamics of the synthesis of melatonin, has been highlighted certain mechanisms of influence on the reproductive function, antioxidant and immunomodulatory properties. The results of many studies melatonin has confirmed participation in the carcinogenesis process, by changing the proliferative and apoptotic activity, inhibition of telomerase activity. As a result of the carried-out analysis it is possible to conclude existence at melatonin of ability to regulate biological rhythms, antioxidatic and antitumoral activity, control over endocrine, nervous, immune systems, ability to provide natural structure of a dream, to slow down processes of aging, influence on development of pregnancy and a fetus

Approximation by the Lamé-Gielis formula of the shell contours at superplastic forming of sheet blanks

Анищенко А. С. Аппроксимация формулами Ляме-Гелиса контура оболочек при сверхпластической формовке листовых заготовок / А. С. Анищенко, В. В. Кухарь, Е. А. Мкртчян // Вісник Приазовського державного технічного університету : зб. наукових праць / ПДТУ. – Маріуполь, 2017. – Вип. 34. – С. 7–17. – (Серія : Технічні науки).Показано, что контур заготовки на всех стадиях сверхпластической формовки может быть описан универсальными формулами, известными как «суперформула» Гелиса и «суперэллипс» Ляме. Определены диапазоны значений коэффициентов, входящих в эти формулы. Проведена аппроксимация предложенными формулами контура оболочек, изготовленных сверхпластической формовкой различными авторами. Показано, что контуры оболочек могут иметь параболообразный и эллипсоидный вид.Показано, що контур заготовки на всіх стадіях надпластичного формування може бути описаний універсальними формулами, що відомі як «суперформула» Геліса або «супереліпс» Ляме. Визначені діапазони значень коефіцієнтів, які входять в ці формули. Проведена апроксимація наданими формулами контуру оболонок, що виготовлені надпластичним формуванням різними авторами. Показано, що контури оболонок можуть мати параболоподібний та еліпсоподібний вигляд.The paper shows that the contour of a sheet blank at all stages of superplastic forming can be described using universal formulas known as a «superformula» Gielis and «superellipse» Lamé. The work provides information on the values range of the coefficients entering into these formulas. The paper shows the results of approximation by means of the proposed formulas of shell contours manufactured by superplastic forming by different methods. The application of the «superformula» to approximate the spherical shell contours in the first stage of molding has been tested. The graphs that show the ratio of the ordinates of the contours of the spherical shells and the hemisphere are given. It is shown that the contours of the shells from the AlMg5 and Pb-38%Sn alloys are rejected in the direction of the formation of parabolas. It was found that the deviations increase with decreasing the coefficient of high-speed hardening of the alloy of the shell. The contour of AMg6 alloy shells and blanks of variable thickness, with maximum in the central zone, is diverted from the hemisphere towards the ellipse. The first stage of forming in a non-uniform temperature field forms a contour of shells, similar to an ellipse. Forming shells with the ratio of the height (H) and the radius (R) as H = 0,6R in the angular zones of the matrix forms intermediate contours of different shapes. This shape depends on the presence of lubricant between the shell and the bottom of the matrix

Effect of Laser Radiation on the Energy Spectrum of 2D Electrons with Rashba Interaction

Abstract Quasienergy spectrum of the 2D electron gas with Rashba interaction under the influence of high-frequency electromagnetic wave polarized elliptically was obtained. Splitting of energy subbands in the material at the presence of high-frequency laser radiation was revealed. Magnetoconductivity as function of wave intensity was calculated. Conductivity of 2D electron gas was shown to have minimum at the certain values of amplitude of high-frequency electric field