Baryon deceleration by strong chromofields in ultrarelativistic nuclear collisions

It is assumed that strong chromofields are generated at early stages of ultrarelativistic heavy-ion collisions which give rise to a collective deceleration of net baryons from colliding nuclei. We have solved classical equations of motion for baryonic slabs under the action of a time-dependent longitudinal chromoelectric field. It is demonstrated that the slab final rapidities are rather sensitive to the strength and decay time of the chromofield as well as to the back reaction of the produced partonic plasma. The net-baryon rapidity loss of about 2 units, found for most central Au-Au collisions at RHIC, can be explained by the action of chromofields with the initial energy density of about 50 GeV/fm^3. Predictions for the baryon stopping at the LHC are made.Comment: 10 pages in revtex, 3 eps figure

Efficiency of Grinding and Mechanical Activation of Solids in Planetary Ball Mills

We develop the algorithm of the procedure for determin-ing the efficiency of operation of planetary mills which is based on the analysis of the movement of the entire load(balls and material) in drums, with the calculation of energy and frequency characteristics of the interaction between milling bodies and material under treatment. We describe the procedure of determination of the efficient power input consumed for driving the ball load of a plane-tary mill and thus for performing the work of grinding and mechanical activation of the material, and some practical examples of industrial applications of planetary-type mills

Space storms as natural hazards

Eruptive activity of the Sun produces a chain of extreme geophysical events: high-speed solar wind, magnetic field disturbances in the interplanetary space and in the geomagnetic field and also intense fluxes of energetic particles. Space storms can potentially destroy spacecrafts, adversely affect astronauts and airline crew and human health on the Earth, lead to pipeline breaking, melt electricity transformers, and discontinue transmission. In this paper we deal with two consequences of space storms: (i) rise in failures in the operation of railway devices and (ii) rise in myocardial infarction and stroke incidences

trans-Dichloridotetrakis­[1-(2-hydroxy­ethyl)-1H-tetrazole-κN 4]cobalt(II)

The title cobalt(II) complex, [CoCl2(C3H6N4O)4], was obtained from metallic cobalt by direct synthesis. There are two Co atoms in the asymmetric unit, each lying on an inversion centre and adopting a distorted octa­hedral coordination. Classical and non-classical hydrogen bonds are responsible for formation of a three-dimensional polymeric network in the crystal

catena-Poly[cobalt(II)-di-μ-chlorido-κ4 Cl:Cl-μ-1,5-dimethyl-1H-tetra­zole-κ2 N 3:N 4]: an X-ray powder investigation

The asymmetric unit of the title compound, [CoCl2(C3H6N4)]n, contains two Co atoms, both lying on inversion centres, two Cl atoms and one 1,5-dimethyl­tetra­zole ligand. The coordination polyhedra of both Co atoms adopt flattened octa­hedral geometry, with two N atoms from two ligands in axial positions and four Cl atoms in equatorial sites. Neighbouring Co atoms are linked together via two bridging Cl atoms and one tetra­zole ring to form polymeric chains running along the a axis

Mechanochemical Synthesis of Intermetallic Compounds in the System Gallium – Ruthenium

Received: 28.12.2020. Revised: 05.02.2021. Accepted: 05.02.2021. Available online: 08.02.2021.This article belongs to the PCEE-2020 Special Issue.The interaction of a solid inert metal Ru with liquid active metal Ga during mechanical activation in a high-energy planetary ball mill was studied using the X-ray diffraction and the high resolution scanning electron microscopy with energy dispersive X-ray microanalyses. This paper considers mechanical activation effects on formation of intermetallic compounds GaxRuy and their solubility in concentrated acids. Gallium is a surface-active substance with respect to Ruthenium. Under intensive mechanical treatment, liquid Gallium penetrates into grain boundaries of polycrystalline Ruthenium particles and sharply reduces their strength. Because of severe mechanical deformation, an intensive increase of contact surface between solid and liquid metals observed, which a place of rapid formation of intermetallic compounds. This processing leads to high reactive products of mechanical activation of Ga + Ru. Their interaction with a mixed concentrated hydrochloric and nitric acid allows Ruthenium (~37%) to pass into an acidic solution, forming complex compounds of the HxRuCly type (H2RuCl6).The research was carried out within the state assignment to ISSCM SB RAS (project No. 0237-2021-0002)

catena-Poly[[bis­[1-(2-hydroxy­ethyl)-1H-tetra­zole-κN 4]copper(II)]-di-μ-chlorido]: a powder study

The crystal structure of the title polymeric complex, [CuCl2(C3H6N4O)2]n, was obtained by the Rietveld refinement from laboratory X-ray powder diffraction data collected at room temperature. The unique CuII ion lies on an inversion center and is in a slightly distorted octa­hedral coordination environment. In the hydroxy­ethyl group, all H atoms, the O atom and its attached C atom are disordered over two positions; the site occupancy factors are ca 0.6 and 0.4. The OH group is involved in an intra­molecular O—H⋯N hydrogen bond

Wettability of amorphous and nanocrystalline Fe78B13Si9 substrates by molten Sn and Bi

The wettability of amorphous and annealing-induced nanocrystalline Fe78B13Si9 ribbons by molten Sn and Bi at 600 K was measured using an improved sessile drop method. The results demonstrate that the structural relaxation and crystallization in the amorphous substrates do not substantially change the wettability with molten Bi because of their invariable physical interaction, but remarkably deteriorate the wettability and interfacial bonding with molten Sn as a result of changing a chemical interaction to a physical one for the atoms at the interface