The Formation of Low-Mass Double White Dwarfs through an Initial Phase of Stable Non-Conservative Mass Transfer

Although many double white dwarfs (DWDs) have been observed, the evolutionary channel by which they are formed from low-mass/long-period red-giant-main-sequence (RG-MS) binaries remains uncertain. The canonical explanations involve some variant of double common-envelope (CE) evolution, however it has been found that such a mechanism cannot produce the observed distribution. We present a model for the initial episode of mass transfer (MT) in RG-MS binaries, and demonstrate that their evolution into double white dwarfs need not arise through a double-CE process, as long as the initial primary's core mass (Md,c) does not exceed 0.46M$_{\odot}$. Instead, the first episode of dramatic mass loss may be stable, non-conservative MT. We find a lower bound on the fraction of transferred mass that must be lost from the system in order to provide for MT, and demonstrate the feasibility of this channel in producing observed low-mass (with M$_{d,c}$ < 0.46M$_{\odot}$) DWD systems.Comment: 2 pages, 1 figure, Conference Proceedings for the International Conference on Binaries, Mykonos, Greec

Emotional paths leading to opportunity desirability and feasibility beliefs through controllability

This is the final version. Available from Sage Publications via the DOI in this record.Extant studies promote opportunity belief as an antecedent of entrepreneurial action. However, we do not sufficiently understand how beliefs about the desirability and feasibility of an entrepreneurial opportunity are formed. We argue that desirability and feasibility are related but distinct micro-foundations of entrepreneurial action formed through different cognitive-emotional mechanisms. Drawing on the appraisal tendency framework, we investigate the indirect effects of three basic emotions (anger, fear and happiness) on desirability and feasibility through the appraisal tendency of controllability. In an experimental study (N= 191), we find evidence for the distinctiveness and interconnectedness of desirability and feasibility beliefs. In addition, our findings show that desirability can be predicted by emotions through controllability, but we cannot predict feasibility through the same appraisal process. Our study seeks insights concerning how desirability and feasibility beliefs regarding an entrepreneurial opportunity are distinctively formed based on the inner cognitive and emotional processes of individuals

Self-dual Yang-Mills fields in pseudoeuclidean spaces

The self-duality Yang-Mills equations in pseudoeuclidean spaces of dimensions $d\leq 8$ are investigated. New classes of solutions of the equations are found. Extended solutions to the D=10, N=1 supergravity and super Yang-Mills equations are constructed from these solutions.Comment: 9 pages, LaTeX, no figure

Research on solid biofuels from cotton waste biomass – alternative for Tajikistan’s energy sector development

ArticleAn increasing awareness of the negative environmental cost associated with the combustion of fossil fuels and concerns over the geopolitical instability of the main oil producing regions is driving the development of renewable energy sources and biofuels. Use of solid biofuels made of different types of biomass became perspective alternative to conventional fuels in many countries. Such positive indicators as low cost of the final product that meets the quality of standards, not capital intensive production, possibility of producing briquettes/pellets from almost any agricultural waste or combination of raw materials are undoubted advantages of biomass based fuels. The main challenges for Tajikistan’s energy sector, which is depended on energy imports, are: to increase energy supply through better exploitation of hydropower and other renewable energy sources such as wind, solar and primary biofuels. Within the agricultural sector of Tajikistan, which is highly agrarian country, cotton accounts for 60% of agricultural output. According to the Ministry of Agriculture of Tajikistan 199,400 hectares of lands have been allocated to cotton cultivation in the year of 2014. Plenty of unused cotton residual biomass could be effectively utilized for winter heating in rural areas. The main focus of the research was to investigate and assess physical, chemical and mechanical properties of pellets and briquettes produced form cotton waste biomass

Carrying out thermodynamic calculations and definition of the main reactions of decomposition of vapours of ethyl alcohol

Thermodynamic opportunities of course of chemical reactions of decomposition of the vapors of ethyl alcohol necessary at development of devices where these reactions will take place are considered. The entalpiyny method of calculation of constants of balance of probable chemical reactions is given in the Excel editor. Independent reactions of process of oxidation are defined. By result of thermodynamic calculation of each reaction schedules of dependence of a constant of balance on environment temperature from which follows are constructed that one reactions proceed until the end of aside formation of the final products, and others are improbable or impossible. The analysis of the received results shows that reactions of oxidation will successfully proceed in the established directions, and for an intensification of process of decomposition it is necessary to provide a supply of some energy which quantity will be sufficient for oxidation of vapors of ethyl alcohol. Results of calculations showed good convergence with programs of thermodynamic calculations like "Aster-4" and "TERRA"

Content of biologically active substances in sweet cherry fruits at different stages of fruit development in the conditions of the living mulch

Received: August 19th, 2022 ; Accepted: October 7th, 2022 ; Published: October 19th, 2022 ; Correspondence: [email protected]Сontent of soluble solids, sugars, titrated acids, ascorbate, glutathione, phenolic substances, anthocyanins, total reducing activity of fruits tissues in sweet cherry fruits studied at different stages of fruit development during 2018 and 2019 in an organic sweet cherry orchard (Prunus avium L. / Prunus mahaleb) in the Southern Steppe of Ukraine. The aim of the research was to determine how the living much conditions (compared to bare fallow) affect the content of biologically active substances in sweet cherry fruits at different stages of ripening. It was determined that the fruits of sweet cherry accumulated significantly more ascorbate, phenolic substances and anthocyanins in the conditions of living mulch (compared to the fruits of the trees on bare fallow). So, at the stage of picking ripeness, the content of ascorbate in sweet cherry fruits in the conditions of living mulch was 29 and 22% more compared to bare fallow (respectively, in 2018 and 2019), phenolic substances - by 47 and 23%, anthocyanins - by 36 and 26%. The revealed regularities can be explained by stressful conditions of competition with natural herbs, which activate the synthesis of anti-stress, antioxidant biologically active substances in plant tissues (including fruits). Since it is the antioxidants of the fruits that have a physiological value for humans, it can be stated that the fruits grown in the conditions of living mulch have a higher therapeutic and preventive value than the fruits grown on bare fallow

Expertise of the documentation substantiating the equipment safety containing radioactive substances

It is stated that expertise of the documentation substantiating the equipment safety containing radioactive substances is impossible without a license from the expert organization for this type of activity. It is underlined that one of the compulsory requirements for obtaining a license is the development, deployment and implementation of the quality assurance program, which also contributes to the quality of work for the expertise of documentationУтверждается, что проведение экспертизы документации, обосновывающей безопасность оборудования, содержащего радиоактивные вещества, невозможно без наличия у экспертной организации лицензии на осуществление данного вида деятельности. Подчеркивается, что одним из обязательных условий получения лицензии является разработка, ввод в действие и выполнение программы обеспечения качества, которая к тому же способствует обеспечению качественного выполнения работ по проведению экспертизы документаци