Supernova Ia: a Converging Delayed Detonation Wave

A model of a carbon-oxygen (C--O) presupernova core with an initial mass 1.33 M_\odot, an initial carbon mass fraction 0.27, and with an average mass growth-rate 5 x 10^{-7} M_\odot/yr due to accretion in a binary system was evolved from initial central density 10^9 g/cm^3, and temperature 2.05 x 10^8 K through convective core formation and its subsequent expansion to the carbon runaway at the center. The only thermonuclear reaction contained in the equations of evolution and runaway was the carbon burning reaction 12C + 12C with an energy release corresponding to the full transition of carbon and oxygen (with the same rate as carbon) into 56Ni. As a parameter we take \alpha_c - a ratio of a mixing length to the size of the convective zone. In spite of the crude assumptions, we obtained a pattern of the runaway acceptable for the supernova theory with the strong dependence of its duration on \alpha_c. In the variants with large enough values of \alpha_c=4.0 x 10^{-3} and 3.0 x 10^{-3} the fuel combustion occurred from the very beginning as a prompt detonation. In the range of 2.0 x 10^{-3} >= \alpha_c >= 3.0 x 10^{-4} the burning started as a deflagration with excitation of stellar pulsations with growing amplitude. Eventually, the detonation set in, which was activated near the surface layers of the presupernova (with m about 1.33 M_\odot) and penetrated into the star down to the deflagration front. Excitation of model pulsations and formation of a detonation front are described in detail for the variant with \alpha_c=1.0 x 10^{-3}.Comment: 13 pages, 11 figures, to appear in Astronomy Letter

Modern features of organization’s management system in Germany on the example of BASF LLC

An organization’s management system plays an important role in the activities of enterprises. In the context of changes in the production sector, it is necessary to adapt and modernize management system to maintain a company’s competitiveness, and it explains the relevance of the research topic. Without periodic research, analyzing trends and opportunities in markets where business activities are conducted, it is impossible to form an effective management model. Insider model of company organization and German company BASF were chosen for the study. The purpose of the study is to define the concept of management system, analyze and characterize insider management model and trace its features in the BASF management system. Among the research objectives are the following: to summarize, analyze and form the characteristics of the German management system, consider the BASF management system and trace the features of the German model in it. Such research methods as synthesis, analysis, structuring, and deduction have been used in the article. The study concludes that BASF management structure contains features of insider management model (social orientation, focus on high-quality products, implementation and improvement of technological developments, use of modernized management methods, and highly qualified personnel)

Designing pseudocubic perovskites with enhanced nanoscale polarization

A crystal-chemical framework has been proposed for the design of pseudocubic perovskites with nanoscale ferroelectric order, and its applicability has been demonstrated using a series of represen- tative solid solutions that combined ferroelectric (K 0.5 Bi 0.5 TiO 3 , BaTiO 3 , and PbTiO 3 ) and antifer- roelectric (Nd-substituted BiFeO 3 ) end members. The pseudocubic structures obtained in these systems exhibited distortions that were coherent on a scale ranging from sub-nanometer to tens of nanometers, but, in all cases, the macroscopic distortion remained unresolvable even if using high- resolution X-ray powder diffraction. Different coherence lengths for the local atomic displacements account for the distinctly different dielectric, ferroelectric, and electromechanical properties exhib- ited by the samples. The guidelines identified provide a rationale for chemically tuning the coher- ence length to obtain the desired functional response

CELL DEATH DIFFERENTIATION IN BLACK HEADED RAMS SPERMATOZOA, USING FLUORESCENT LABELED ANNEXIN V

Double staining kit of Annexin V Cy3.18/6-CFDA was used to investigate the changes in phospholipide asymmetry after treating sperm cells with dexamethasone. The % of spermatozoa with registered translocation of PS in treated with dexamethazone groups at the 10-th min and in control no treated varied from 2.74%±0.65 to 2.30%±0.89. After the 5 hour of incubation these % increased to 39.83±3.33 for the treated group and 23.44±1.12 for the control. It was concluded that Annexin V binding assay is more sensitive in the detection of deterioration in membrane function than other conventional methods such as motility analysis and supravital techniques

Surface structure of commercially pure VT1-0 titanium irradiated by an intense pulsed electron beam

It is shown that pulsed electron beam irradiation of commercially pure titanium at a beam energy density of 10 J/cm{2}, pulse duration of 150 [mu]s, number of pulses of N=5 pulses, and pulse repetition frequency of 0.3 Hz with attendant polymorphic [alpha]->[beta]->[ alpha] transformations allows a more than five-fold decrease in the grain and subgrain sizes of the material structure

Yang-Mills instantons and dyons on homogeneous G_2-manifolds

We consider Lie G-valued Yang-Mills fields on the space R x G/H, where G/H is a compact nearly K"ahler six-dimensional homogeneous space, and the manifold R x G/H carries a G_2-structure. After imposing a general G-invariance condition, Yang-Mills theory with torsion on R x G/H is reduced to Newtonian mechanics of a particle moving in R^6, R^4 or R^2 under the influence of an inverted double-well-type potential for the cases G/H = SU(3)/U(1)xU(1), Sp(2)/Sp(1)xU(1) or G_2/SU(3), respectively. We analyze all critical points and present analytical and numerical kink- and bounce-type solutions, which yield G-invariant instanton configurations on those cosets. Periodic solutions on S^1 x G/H and dyons on iR x G/H are also given.Comment: 1+26 pages, 14 figures, 6 miniplot