DETERMINATION OF CHAMBER AND PISTON GEOMETRY FOR A ROTARY TYPE EXPANSION MACHINE

The article deals with the determination of chamber and piston geometry for a rotary expansion machine. Analytical expressions for the working surface area of piston and for chamber volume are derived. Three defining parameters of the expansion machine were obtained: gas dynamic machine constant Cp; constant M0 connecting torque and Cp; the main dimensionless parameter of the machine Q0, which relates the volume of the chamber and the torque

CONSTRUCTION OF PISTON OUTER PROFILE FOR ROTARY TYPE EXPANSION MACHINE

The article discusses methods for constructing piston outer profile for the rotary type expansion machine in order to reduce unwanted (parasitic) volumes and offers options for constructing outer profile of piston using analytical and geometric methods

OPTIMIZATION OF MECHANICAL STRENGTH OF ROTARY-VANE ENGINE

The article discusses a rotory-vane heat engine with a lever-cam mechanism motion conversion (an engine may be an internal combustion or external combustion). The output shaft of the engine adds drive torque from the working fluid pressure forces acting on the blade and the inertial moment of the forces of inertia of engine components. The mechanical strength of the motor is dependent on the magnitude and phase of these two torque. The purpose of the article is to determine the conditions under which mechanical strength is minimized

Multifunctional Spirocyclic Systems

New spiropyrans with different substituents in the benzopyran fragment have been synthesized and investigated. It was shown that introduction of aldehyde group in the structure of spiropyrans gives a possibility to obtain new functionalized compounds. Effects of the substituents on the photochromic behavior were studied

Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTIC‐HF: baseline characteristics and comparison with contemporary clinical trials

Aims: The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC‐HF) trial. Here we describe the baseline characteristics of participants in GALACTIC‐HF and how these compare with other contemporary trials. Methods and Results: Adults with established HFrEF, New York Heart Association functional class (NYHA) ≥ II, EF ≤35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic‐guided dosing: 25, 37.5 or 50 mg bid). 8256 patients [male (79%), non‐white (22%), mean age 65 years] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NT‐proBNP 1971 pg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTIC‐HF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure < 100 mmHg (n = 1127), estimated glomerular filtration rate < 30 mL/min/1.73 m2 (n = 528), and treated with sacubitril‐valsartan at baseline (n = 1594). Conclusions: GALACTIC‐HF enrolled a well‐treated, high‐risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation

DESIGN OF WELDED JOINTS PROVIDING LOW-CYCLE FATIGUE AT THE LEVEL OF BASE METAL

The test data of welded joints with butt and fillet welds on l ow - cycle fatigue under biaxial tension in the corrosive environment are considered. Some constructive techniques for improving the fatigue strength of welde d joints through changing the weld geometrical parameters are offered

On the issue of conversion of metal deposit development techniques

The relevance of providing industry with metals for supplying the needs of population increases in radical changes in the economic system and continuous deterioration of conditions for exploring mineral deposits using the underground method. The aim of the research is to substantiate the appropriateness of organizational-economic and production-technological measures to convert mining industry to innovative techniques in mineral deposits exploration by the underground method. Research methods include the analysis of international experience and literature, obtaining and processing data based on multiple regression and correlation analysis, pilot plant testing of alternative technologies. Results. It was ascertained that the directions of mining industry conversion include application of solid mixtures for laying-out space and leaching of metals from ores. It is shown that the environmental concept of technological upgrading consists in transferring the processing of the main volume of ores into underground conditions; the efficiency of utilization of tailings consists in reducing the level of damage from tailings, the value of metals and non-metals obtained in processing, raw materials for construction industry and associated commercial products. The feasibility of development of conversion technologies is determined by the ratio of the compensation of costs and damages from waste storage, production capacity of the disposal enterprise and its technological level. Diversification of mining production to underground mining of deposits in near-term perspective requires the correction in engineering support of mining on mountain specialties. Production activities of mining engineers is related to the efficient use of resources, therefore, a mining engineer should be a technologist and processor, hydrogeologist, ecologist, etc. Conversion of technologies is implemented, provided that: the efficiency of ore extraction is based on the value of recoverable and not recoverable metals, and taking into account the effective quantity of damage to the environment. Conclusions: restoration of mining industry potential depends on implementation of innovative technologies, provided adequate engineers of the new generation

On the issue of conversion of metal deposit development techniques

Актуальность проблемы обеспечения промышленности металлами для удовлетворения нужд населения повышается в условиях радикальных изменений в системе хозяйствования и продолжающегося ухудшения условий разработки месторождений полезных ископаемых подземным способом. Цель работы: обоснование целесообразности организационно-экономических и производственно-технологических мероприятий по переходу горной отрасли на инновационные технологии разработки месторождений полезных ископаемых подземным способом. Методы исследования включают в себя анализ мирового опыта и литературных публикаций, получение и обработку данных на основе множественного регрессионного и корреляционного анализа, полупромышленные испытания вариантов альтернативных технологий. Результаты. Определено, что направления конверсии горного производства включают в себя применение твердеющих смесей для закладки выработанного пространства и выщелачивание металлов из руд. Показано, что природоохранный концепт технологического перевооружения состоит в перенесении процессов переработки основного объема руд в подземные условия; эффективность утилизации хвостов обогащения складывается из снижения величины ущерба от хранения хвостов, стоимости полученных при переработке металлов и неметаллов, сырья для строительной индустрии и попутной товарной продукции. Целесообразность освоения конверсионных технологий определяется соотношением компенсационных затрат и ущерба от хранения отходов, производственной мощности утилизирующего предприятия и его технологического уровня. Отмечено, что диверсификация горного производства на подземную разработку месторождений в близкой перспективе требует корректировки инженерного обеспечения горных работ по горным специальностям. Производственная деятельность горных инженеров связана с эффективностью использования природных ресурсов, поэтому горному инженеру надо быть технологом-переработчиком, гидрогеологом, экологом и т. д. Конверсия технологий реализуется при условии: эффективность добычи руд определяется с учетом ценности извлекаемых и не извлекаемых металлов, а также с учетом величины действительного ущерба окружающей среде. Выводы: восстановление потенциала горной отрасли зависит от реализации инновационных технологий при условии надлежащего обеспечения специалистами нового поколения.The relevance of providing industry with metals for supplying the needs of population increases in radical changes in the economic system and continuous deterioration of conditions for exploring mineral deposits using the underground method. The aim of the research is to substantiate the appropriateness of organizational-economic and production-technological measures to convert mining industry to innovative techniques in mineral deposits exploration by the underground method. Research methods include the analysis of international experience and literature, obtaining and processing data based on multiple regression and correlation analysis, pilot plant testing of alternative technologies. Results. It was ascertained that the directions of mining industry conversion include application of solid mixtures for laying-out space and leaching of metals from ores. It is shown that the environmental concept of technological upgrading consists in transferring the processing of the main volume of ores into underground conditions; the efficiency of utilization of tailings consists in reducing the level of damage from tailings, the value of metals and non-metals obtained in processing, raw materials for construction industry and associated commercial products. The feasibility of development of conversion technologies is determined by the ratio of the compensation of costs and damages from waste storage, production capacity of the disposal enterprise and its technological level. Diversification of mining production to underground mining of deposits in near-term perspective requires the correction in engineering support of mining on mountain specialties. Production activities of mining engineers is related to the efficient use of resources, therefore, a mining engineer should be a technologist and processor, hydrogeologist, ecologist, etc. Conversion of technologies is implemented, provided that: the efficiency of ore extraction is based on the value of recoverable and not recoverable metals, and taking into account the effective quantity of damage to the environment. Conclusions: restoration of mining industry potential depends on implementation of innovative technologies, provided adequate engineers of the new generation

Live-Cell STED Microscopy with Genetically Encoded Biosensor

Of the various super-resolution techniques, stimulated emission depletion (STED) microscopy achieves the best temporal resolution at high spatial resolution, enabling live-cell imaging beyond the diffraction limit. However, STED and most other super-resolution imaging methods utilize a particular type of information extractable from the raw data, namely the positions of fluorophores. To expand on the use of super-resolution techniques, we report here the live-cell STED microscopy of a dynamic biosensor. Using the fluorescent H₂O₂ sensor HyPer2 for subdiffraction imaging, we were able not only to image filaments with superior resolution by localizing emission but also to trace H₂O₂ produced within living cell by monitoring brightness of the probe. STED microscopy of HyPer2 demonstrates potential utility of FP-based biosensors for super-resolution experiments in situ and in vivo