Mathematical modeling of heat and mass transfer in a thermal protection coating with gas flow fluctuations

The thermochemical destruction of a carbon fiber-reinforced polymer when affected by a high enthalpy fluctuating gas flow is simulated numerically. The possibility of controlling the heat transfer process in the composite material is studied

Spine-sheath polarization structures in four active galactic nuclei jets

We present the results of multifrequency (15 + 8 + 5 GHz) polarization Very Long Baseline Array (VLBA) observations of the three BL Lacertae objects 0745 + 241, 1418 + 546 and 1652 + 398 together with 5-GHz VLBI Space Observatory Programme (VSOP) observations of 1418 + 546 and 1.6- and 5-GHz VSOP observations of the blazar 1055 + 018. The jets of all these sources have polarization structure transverse to the jet axis, with the polarization E vectors aligned with the jet along the jet spine and 'sheaths' of orthogonal E vectors at one or both edges of the jet. The presence of polarization aligned with the jet near the 'spine' may indicate that the jets are associated with helical B fields that propogate outward with the jet flow; the presence of orthogonal polarization near the edges of the jet may likewise be a consequence of a helical jet B field, or may be owing to an interaction with the ambient medium on parsec scales. We have tentatively detected interknot polarization in 1055 + 018 with E aligned with the local jet direction, consistent with the possibility that the jet of this source is associated with a helical B field

Density of States and Conductivity of Granular Metal or Array of Quantum Dots

The conductivity of a granular metal or an array of quantum dots usually has the temperature dependence associated with variable range hopping within the soft Coulomb gap of density of states. This is difficult to explain because neutral dots have a hard charging gap at the Fermi level. We show that uncontrolled or intentional doping of the insulator around dots by donors leads to random charging of dots and finite bare density of states at the Fermi level. Then Coulomb interactions between electrons of distant dots results in the a soft Coulomb gap. We show that in a sparse array of dots the bare density of states oscillates as a function of concentration of donors and causes periodic changes in the temperature dependence of conductivity. In a dense array of dots the bare density of states is totally smeared if there are several donors per dot in the insulator.Comment: 13 pages, 15 figures. Some misprints are fixed. Some figures are dropped. Some small changes are given to improve the organizatio

Physicochemical aspects of recycling tree leaf litter in the south of Western Siberia by the Eisenia fetida (Savigny) vermiculture

The utility of the compost worm Eisenia fetida (Savigny) for recycling mixed leaf litter of the tree species characteristic of the forests in the south of Western Siberia and used in the landscaping in the city of Tomsk has been demonstrated. The tree species that are the major contributors to the leaf litter in the examined area include the genera Populus, Salix, and Betula. Two-fraction substrates for leaf litter vermicomposting and conventional composting (decomposition with and without earthworms) were prepared of the harvested and dried leaf litter. The feeding fraction consisted of leaf litter moistened with distilled water and the absorbing fraction, of alluvial river sand. The physicochemical properties of the studied leaf litter were weakly acidic pH of aqueous extracts, a very low content of nitrate nitrogen, and a relatively low K + concentration. The prevalent cation in the assayed leaf litter was Ca 2+ . The leaf litter was partially decomposed on the surface of sand substrates during 35-day incubation under humid conditions; accumulation of inorganic ions in the sand was one of the signs indicating this decomposition. Ca 2+ was also prevalent among these ions

Behaviour of rare earth elements in molten salts in relation to pyrochemical reprocessing of spent nuclear fuels

The kinetics of chlorination of lanthanide oxides (by Cl2 and HCl) and precipitation of lanthanide phosphates was studied by in situ electronic absorption spectroscopy in 3LiC1-2KC1 and NaCl-KCl melts at 400-750°C Products of the chlorination are the corresponding hexachlorospecies, LnCl63-, and the rate of chlorination increases with increasing temperature. Composition of the precipitated phosphates depends on the melt composition and 1.5-5 fold excess of phosphate, depending on the nature of lanthanide, is needed for the complete removal of the lanthanides from the melt. Over three hours are required for completing the reaction of phosphate precipitation. copyright The Electrochemical Society.Electrochemical Society, Phys. Anal. Electrochem. Div.;Electrochemical Society, Electrodeposition Division;Electrochemical Society, High Temperature Materials Division;Electrochemical Society, Battery Division;Electrochemical Society, Energy Technology Divisio

The place of anatomical museum in teaching phisiology for non-medical specialities students: traditionsand innovations

Рассмотрен опыт сотрудничества кафедры иммунохимии УрФУ с анатомическим музеем УГМА. Проведение практических занятий по физиологии человека для студентов немедицинских специальностей на базе музея позволяет повысить наглядность преподавания и активизировать познавательную деятельность студентов.Experience of co-working of immunochemistry chair of UrFU and anatomical museum of USMA is described. Teaching physiology in museum for non-medical specialities students increases illustrativity of teaching and studying activity of students

Correlated electron states and transport in triangular arrays

We study correlated electron states in frustrated geometry of a triangular lattice. The interplay of long range interactions and finite residual entropy of a classical system gives rise to unusual effects in equilibrium ordering as well as in transport. A novel correlated fluid phase is identified in a wide range of densities and temperatures above freezing into commensurate solid phases. The charge dynamics in the correlated phase is described in terms of a height field, its fluctuations, and topological defects. We demonstrate that the height field fluctuations give rise to a ``free'' charge flow and finite dc conductivity. We show that freezing into the solid phase, controlled by the long range interactions, manifests itself in singularities of transport properties.Comment: 19 pages, 10 figure