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

SOME AGE PECULIARITIES OF THE WALL STRUCTURE OF ILIAC ARTERIES

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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

Self-Duality in D <= 8-dimensional Euclidean Gravity

In the context of D-dimensional Euclidean gravity, we define the natural generalisation to D-dimensions of the self-dual Yang-Mills equations, as duality conditions on the curvature 2-form of a Riemannian manifold. Solutions to these self-duality equations are provided by manifolds of SU(2), SU(3), G_2 and Spin(7) holonomy. The equations in eight dimensions are a master set for those in lower dimensions. By considering gauge fields propagating on these self-dual manifolds and embedding the spin connection in the gauge connection, solutions to the D-dimensional equations for self-dual Yang-Mills fields are found. We show that the Yang-Mills action on such manifolds is topologically bounded from below, with the bound saturated precisely when the Yang-Mills field is self-dual. These results have a natural interpretation in supersymmetric string theory.Comment: 9 pages, Latex, factors in eqn. (6) corrected, acknowledgement and reference added, typos fixe

Risk assessment in the formation of motivational programs aimed at retaining the heads of organizations

The relevance of the study is determined by the increasing role of risks in the formation of motivation programs aimed at retaining managers of the middle and top levels of organization management. The purpose of the study was to identify risks that arise in the process of implementing motivation programs for managerial personnel. In the study, the following tasks were solved: determining the sources and risk factors; assessing the probability of risks and the level of possible consequences of a risk event; identifying the risks that are most priority for management based on building a risk map; development of ways to reduce risks that reduce the effectiveness of the implementation of motivational programs to retain managers of the organization. The work uses systematic and situational approaches, expert assessment, the survey method and the Delphi method, risk mapping. The developed measures to eliminate risks will allow organizations to prevent reputational and financial losses and analyze the effectiveness of each implemented motivational tool to retain the leaders of the organization

Theoretical basis for composition of economic strategy for industry development

The article deals with the issues related to analysis of domestic engineering problems with the assessment of the current state of the industry as a whole. Considering the prospects of exiting the current crisis, as well as long-term economic growth we expect general welfare within the sector. As the object of the study the authors have selected the engineering industry of the country. The subject of research is the economic relations between producers and consumers of engineering products, as well as issues of strategy formation and development of the engineering industry. The authors analyzed the state of machine-manufacture and highlighted the problems, the solution of which is most relevant given the government policy of increased import substitution and enhanced productivity. Further analysis was carried out in the sphere of sources of financing and attraction of investment resources for all kinds of enterprises of mechanical engineering, on the basis of which economic development strategy for the industry may be constructed. In addition, the authors propose measures and concrete ways of solving the problems identified by the formation of economic strategy of development of the industry, involving plans of achievement of all the defined targets. As a result of the study authors concluded that the need to stop subsidizing loss-making enterprises, creating a favorable climate for the development of venture companies, in order t introduce innovative technology as soon as possible. These technologies could subsequently be exported together with products of greater added value.peer-reviewe