Исследование технологических свойств процесса сварки дугой горящей в динамическом режиме

В процессе исследования проводился анализ методов повышения эффективности и способы сварки не плавящимся электродом с применением импульсного питания сварочной дуги, проведен анализ моделей столба дуги и предложено феноменологическое описание дуги. В результате исследования разработан способ сварки дугой горящей в динамическом режиме и оборудование, обеспечивающее его реализацию.In the process of research the methods of improving the efficiency and the procedure of welding with non-consumable electrode using welding arc pulsed supply were analyzes, the analysis of arc core models was realized and the arc phenomenal report was suggested. Results of research: the method of the welding arc burning in dynamic mode and equipment ensuring its implementation were developed

Numerical approximation of table functions on the basis of multidimensional optimization methods for modeling physics and technics problems

The aim of the article is to present an approximation method based on multidimensional optimization methods which does not require preliminary information about the derivatives of the approximating function. It is proposed to use a combination of the grid method, coordinate descent method and the golden section method to solve the task of optimizing the objective function (standard deviation in the nodes of the tabular function). The considered example of the approximation of the flight trajectory of a body in the atmosphere illustrates the comparability of the results of the proposed method and the least squares method

HIF1A reduces acute lung injury by optimizing carbohydrate metabolism in the alveolar epithelium

Background: While acute lung injury (ALI) contributes significantly to critical illness, it resolves spontaneously in many instances. The majority of patients experiencing ALI require mechanical ventilation. Therefore, we hypothesized that mechanical ventilation and concomitant stretch-exposure of pulmonary epithelia could activate endogenous pathways important in lung protection. Methods and Findings: To examine transcriptional responses during ALI, we exposed pulmonary epithelia to cyclic mechanical stretch conditions—an in vitro model resembling mechanical ventilation. A genome-wide screen revealed a transcriptional response similar to hypoxia signaling. Surprisingly, we found that stabilization of hypoxia-inducible factor 1A (HIF1A) during stretch conditions in vitro or during ventilator-induced ALI in vivo occurs under normoxic conditions. Extension of these findings identified a functional role for stretch-induced inhibition of succinate dehydrogenase (SDH) in mediating normoxic HIF1A stabilization, concomitant increases in glycolytic capacity, and improved tricarboxylic acid (TCA) cycle function. Pharmacologic studies with HIF activator or inhibitor treatment implicated HIF1A-stabilization in attenuating pulmonary edema and lung inflammation during ALI in vivo. Systematic deletion of HIF1A in the lungs, endothelia, myeloid cells, or pulmonary epithelia linked these findings to alveolar-epithelial HIF1A. In vivo analysis of 13C-glucose metabolites utilizing liquid-chromatography tandem mass-spectrometry demonstrated that increases in glycolytic capacity, improvement of mitochondrial respiration, and concomitant attenuation of lung inflammation during ALI were specific for alveolar-epithelial expressed HIF1A. Conclusions: These studies reveal a surprising role for HIF1A in lung protection during ALI, where normoxic HIF1A stabilization and HIF-dependent control of alveolar-epithelial glucose metabolism function as an endogenous feedback loop to dampen lung inflammation

Динамика фрикционных процессов при трении нержавеющей стали аустенитного класса 12Х18Н10Т с ультрамелкозернистой структурой

В работе рассматривается экспериментальное исследование динамики фрикционных процессов при трении объемных ультрамелкозернистых материалов. В качестве модельных образцов использовалась нержавеющая сталь аустенитного класса 12Х18Н10Т с ультрамелкозернистой структурой, сформированной методами ABC прессования и прокатки. В процессе сухого трения скольжения осуществлялась регистрация сигналов виброускорений и акустической эмиссии

ИССЛЕДОВАНИЕ РЕЖИМНыХ ПАРАМЕТРОВ СЕПАРАТОРА СісП-1,4-МПт

В настоящее время для переработки техногенных месторождений, содержащих уголь, применяются обогатительные установки на базе пневматических сепараторов

Estimation of field production profiles in case of asphaltene deposition

In this work, we aimed to predict possible field production scenarios in case of asphaltene deposition based on field data as well as recommend remediation and stimulation measures to mitigate the risks of asphaltene deposition in the reservoir. We considered the influence of asphaltene formation in the near-wellbore of producers on the production data without reservoir pressure maintenance system in one of the oil fields. The asphaltene envelope in the reservoir oil was obtained, and the operating conditions of the field were evaluated under the possibility of asphaltene deposition. According to the results of dynamic modeling, the pressure map was plotted and the low-pressure areas in the near-wellbore were shown, which contributes to the aggravation of the problem associated with the asphaltene envelope. Based on the geometrical features of the low-pressure area, the dependence of the permeability reduction in the near-wellbore of the production well on the operating time was obtained using the asphaltene deposition model proposed by Wang and Civan. Based on the Buckley-Leverett theory, the field production profiles were calculated with and without asphaltene deposition. A decrease in the oil rate and consequently, the decrease in cumulative oil production in the field is expected due to the damage formation by solids. Maintenance of the production level will be facilitated by treating the nearwellbore with aromatic solvents and maintaining the reservoir pressure above the asphaltene onset pressure