Electroerosive Powder Obtained from Alloy VK8 Waste into Butanol

The results of studies of the properties of the powders obtained by electroerosive dispersing of the hard alloy wastes of mark VK8 in butanol. It is found that the powder particles obtained by electroerosive dispersing of waste carbide grade VK8 in butyl alcohol, consist of the following major elements: W, Co, Fe, C and O

Structure, Substructure, Hardness and Adhesion Strength of Multiperiod Composite Coatings MoN / CrN

A comprehensive study of the influence of the thickness of the layers, Us and PN on the structural engineering to obtain high mechanical properties in multilayer composite MoN / CrN vacuum-arc coatings has been conducted by means of scanning electron microscopy with energy analysis, X-ray diffraction studies microindentation and scratch testing methods. It has been determined that in the studied PN (2- 30) 10 – 4 Torr, the content of nitrogen in the coatings varies from 6.3 to 33 at. %, which leads even at the greatest nitrogen content to the formation of lower phase by nitrogen, -Mo2N and isostructural CrN with the vacant sites in the nitrogen sublattice. The increase of thickness of the layers applied on the substrate in a stationary state promotes the increase of nitrogen content. Along with this, the lowest microdeformation and the average size of crystallites are formed at Ub – 300 V, which defines the achievement of greater hardness of 35 GPa and high adhesion strength, which resists the destruction, Lc5 187.6 N

Экономическая эффективность селекции и семеноводства овощных культур

The subject of breeding and seed production has been studied as an innovative process, the result of which is new varieties and hybrids. At All-Russian Research Institute of Vegetable Breeding Production where the results of this complex system work can be exemplified. Cost efficiency of selection and seed production is analyzed, and methods of its perfection are offered. It has been proven that there is a necessity to build a State Corporation for seed production as a main link between modern economics and the seed production sector.Раскрыта сущность селекционно-семеноводческой деятельности как инновационного процесса, итогом которого является новая продукция - сорт (гибрид). На примере Всероссийского НИИ селекции и семеноводства овощных культур показаны результаты этой комплексной, системной работы. Дана оценка экономической эффективности селекции и семеноводства, предложены методы её совершенствования. Предлагается создание государственной корпорации семеноводства овощных культур

Physical and Mechanical Properties of (Ti-Zr-Nb)N Coatings, Fabricated by Vacuum-Arc Deposition

The coatings based on (Ti-Zr-Nb)N were fabricated by vacuum-arc deposition of the Ti+Zr+Nb cathodes in the nitrogen atmosphere. Their physical and mechanical properties as well as tribological characteristics have been studied. The coatings are characterized by a columnar structure, their hardness reaches 44.57 GPa. The adhesion strength of coatings reaches 66.77 GPa, the friction coefficient of the «cover – Al2O3» is 1.1. It has been determined, that the hardness of the investigated coatings significantly depends on the pressure of the reaction gas. The coatings are promising as protective coatings for friction pairs and cutting tools

Physical and Mechanical Properties of (Ti-Zr-Nb)N Coatings, Fabricated by Vacuum-Arc Deposition

The coatings based on (Ti-Zr-Nb)N were fabricated by vacuum-arc deposition of the Ti+Zr+Nb cathodes in the nitrogen atmosphere. Their physical and mechanical properties as well as tribological characteristics have been studied. The coatings are characterized by a columnar structure, their hardness reaches 44.57 GPa. The adhesion strength of coatings reaches 66.77 GPa, the friction coefficient of the «cover – Al2O3» is 1.1. It has been determined, that the hardness of the investigated coatings significantly depends on the pressure of the reaction gas. The coatings are promising as protective coatings for friction pairs and cutting tools

Hadrons with Charm and Beauty

By combining potential models and QCD spectral sum rules (QSSR), we discuss the spectroscopy of the $(b\bar c)$ mesons and of the $(bcq)$, $(ccq)$ and $(bbq)$ baryons (${q}\equiv {d}$ or $s$), the decay constant and the (semi)leptonic decay modes of the $B_c$ meson. For the masses, the best predictions come from potential models and read: $M_{B_c} = (6255 \pm 20)$~MeV, $M_{B^*_c} = (6330 \pm 20)$~MeV, $M_{\Lambda(bcu)} = (6.93\pm 0.05)$~GeV, $M_{\Omega(bcs)} = (7.00\pm 0.05)$~GeV, $M_{\Xi^*(ccu)} =(3.63\pm 0.05)$~GeV and $M_{\Xi^*(bbu)} = (10.21\pm 0.05)$~GeV. The decay constant $f_{B_c} = (2.94 \pm 0.21) f_\pi$ is well determined from QSSR and leads to: $\Gamma(B_c \rightarrow \nu_\tau \tau) = (3.0 \pm 0.4)( V_{cb}/0.037 )^2$ $\times 10^{10}$ s$^{-1}$.The uses of the vertex sum rules for the semileptonic decays of the $B_c$ show that the $t$-dependence of the form factors is much stronger than predicted by vector meson dominance. It also predicts the almost equal strength of about 0.30 $\times 10^{10}$ sec$^{-1}$ for the semileptonic rates $B_c$ into $B_s, B^*_s,\eta_c$ and J/$\psi$. Besides these phenomenological results, we also show explicitly how the Wilson coefficients of the $\langle\alpha_s G^2\rangle$ and $\langle G^3\rangle$ gluon condensates already contain the full heavy quark- ($\langle\bar QQ\rangle$) and mixed- ($\langle\bar QGQ\rangle$) condensate contributions in the OPE.}Comment: 32 pages, LaTeX, no changes in the 1994 paper, latex errors corrected in 201

Quantum phase transitions from topology in momentum space

Many quantum condensed matter systems are strongly correlated and strongly interacting fermionic systems, which cannot be treated perturbatively. However, physics which emerges in the low-energy corner does not depend on the complicated details of the system and is relatively simple. It is determined by the nodes in the fermionic spectrum, which are protected by topology in momentum space (in some cases, in combination with the vacuum symmetry). Close to the nodes the behavior of the system becomes universal; and the universality classes are determined by the toplogical invariants in momentum space. When one changes the parameters of the system, the transitions are expected to occur between the vacua with the same symmetry but which belong to different universality classes. Different types of quantum phase transitions governed by topology in momentum space are discussed in this Chapter. They involve Fermi surfaces, Fermi points, Fermi lines, and also the topological transitions between the fully gapped states. The consideration based on the momentum space topology of the Green's function is general and is applicable to the vacua of relativistic quantum fields. This is illustrated by the possible quantum phase transition governed by topology of nodes in the spectrum of elementary particles of Standard Model.Comment: 45 pages, 17 figures, 83 references, Chapter for the book "Quantum Simulations via Analogues: From Phase Transitions to Black Holes", to appear in Springer lecture notes in physics (LNP

Structure, Substructure, Hardness and Adhesion Strength of Multiperiod Composite Coatings MoN / CrN

A comprehensive study of the influence of the thickness of the layers, Us and PN on the structural engineering to obtain high mechanical properties in multilayer composite MoN / CrN vacuum-arc coatings has been conducted by means of scanning electron microscopy with energy analysis, X-ray diffraction studies microindentation and scratch testing methods. It has been determined that in the studied PN (2- 30) 10 – 4 Torr, the content of nitrogen in the coatings varies from 6.3 to 33 at. %, which leads even at the greatest nitrogen content to the formation of lower phase by nitrogen, -Mo2N and isostructural CrN with the vacant sites in the nitrogen sublattice. The increase of thickness of the layers applied on the substrate in a stationary state promotes the increase of nitrogen content. Along with this, the lowest microdeformation and the average size of crystallites are formed at Ub – 300 V, which defines the achievement of greater hardness of 35 GPa and high adhesion strength, which resists the destruction, Lc5 187.6 N

Using Heavy Quark Spin Symmetry in Semileptonic BcB_c Decays

The form factors parameterizing the B_c semileptonic matrix elements can be related to a few invariant functions if the decoupling of the spin of the heavy quarks in B_c and in the mesons produced in the semileptonic decays is exploited. We compute the form factors as overlap integral of the meson wave-functions obtained using a QCD relativistic potential model, and give predictions for semileptonic and non-leptonic B_c decay modes. We also discuss possible experimental tests of the heavy quark spin symmetry in B_c decays.Comment: RevTex, 22 pages, 2 figure

Current Status of Simulations

As the title suggests, the purpose of this chapter is to review the current status of numerical simulations of black hole accretion disks. This chapter focuses exclusively on global simulations of the accretion process within a few tens of gravitational radii of the black hole. Most of the simulations discussed are performed using general relativistic magnetohydrodynamic (MHD) schemes, although some mention is made of Newtonian radiation MHD simulations and smoothed particle hydrodynamics. The goal is to convey some of the exciting work that has been going on in the past few years and provide some speculation on future directions.Comment: 15 pages, 14 figures, to appear in the proceedings of the ISSI-Bern workshop on "The Physics of Accretion onto Black Holes" (8-12 October 2012