Method for the Optimal Design of Vacuum-Evaporative Heat Pumps

A method is developed for optimally designing vacuum-evaporative heat pumps that use water (R718) as a refrigerant. This method is based on the autonomous method of the thermoeconomic optimization of thermodynamic systems, and makes it possible, when optimizing the design and choosing economical modes of system operation, to simultaneously take into account both thermodynamic and economic parameters.На базі автономного методу термоекономічної оптимізації термодинамічних систем розроблена методика оптимального проектування вакуумно-випарних теплових насосів, що використовують воду (R718) як холодоагент. Ця методика дозволяє під час оптимізації конструкції і вибору економічних режимів роботи системи одночасно враховувати як термодинамічні, так і економічні параметри.На базе автономного метода термоэкономической оптимизации термодинамических систем разработана методика оптимального проектирования вакуумно-испарительных тепловых насосов, использующих в качестве хладагента воду (R718). Эта методика позволяет при оптимизации конструкции и выборе экономичных режимов работы системы одновременно учитывать как термодинамические, так и экономические параметры

Instanton bundles on Fano threefolds

We introduce the notion of an instanton bundle on a Fano threefold of index 2. For such bundles we give an analogue of a monadic description and discuss the curve of jumping lines. The cases of threefolds of degree 5 and 4 are considered in a greater detail.Comment: 31 page, to appear in CEJ

Semiclassical Study of Baryon and Lepton Number Violation in High-Energy Electroweak Collisions

We make use of a semiclassical method for calculating the suppression exponent for topology changing transitions in high-energy electroweak collisions. In the Standard Model these processes are accompanied by violation of baryon and lepton number. By using a suitable computational technique we obtain results for s-wave scattering in a large region of initial data. Our results show that baryon and lepton number violation remains exponentially suppressed up to very high energies of at least 30 sphaleron masses (250 TeV). We also conclude that the known analytic approaches inferred from low energy expansion provide reasonably good approximations up to the sphaleron energy (8 TeV) only.Comment: 23 pages, 18 figures. Phys.Rev.D journal version (two references added

Copper Recovery from Water of Soryinskoye Tailing Pond

The large volume of recycling waters from the Soryinskoye tailing pond (up to 1300 m3/h) offers interesting possibilities for processing concentrates despite the low copper content (5.2-16.4 mg/l). Sulfides precipitation is the most efficient method of heavy metal ions removal from water. In this study, a sulfur solution in sodium hydroxide was used as a sulfidizing agent for precipitation. Commercial liquid alkali (NaOH – 46) and commercial sulfur were the initial agents. Due to the concentrated alkali, dissolution could be carried out at 115-120∘С, which is higher than the melting point of sulfur. Stable solutions were obtained at a weight ratio of NaOH: S = 1: 1 and a sulfur concentration of 350 g/l. During the laboratory and scale-up laboratory tests, the optimal consumption of sulfidizing agent was determined (110% of the stoichiometry for the formation of Cu2S, and copper extraction into the precipitate from the solution was more than 90.0% with high selectivity towards Zn and Fe). An extended analysis of the composition of the sediment (x-ray fluorescence spectrometer SPECTRO XEPOS) obtained during pilot trials showed that the main elements are, %: sulfur 58.4; oxygen 16.2; copper 8.9; iron 5.7; calcium 4.7 and arsenic 3.8. The total fraction of impurity elements does not exceed 2.3%. This study assumes use of the product conditioning to obtain concentrate with increased copper content and sulfur return to sulfidation stage. Keywords: acid mine drainage, copper recovery, chemical treatment, sulfide precipitatio

Multipoint Vernier VISAR Interferometer System for Measuring Mass Velocity in Shock Wave Experiments

AbstractThe results of development of a laser interferometer designed to measure the mass velocity of condensed substances in shock wave experiments in the field of high energy density physics are presented. The developed laser system allows measurements of the velocity of free surfaces of samples in shockwave experiments with accuracy no worse than 10 m/s for the entire range of velocities attained experimentally. The time resolution of measurements is limited by the response speed of the used PMTs and amounts to 2.5 ns

История и современность кафедры ботаники, физиологии растений и агробиотехнологии

The article presents the formation and development history, modern educational and scientific activity of the Chair of botany, plant physiology and agrobiotechnology - the oldest chair of the Agrarian faculty of PFUR.В статье представлена история становления и развития, а также современная образовательная и научная деятельность кафедры ботаники, физиологии растений и агробиотехнологии - старейшей кафедры аграрного факультета РУДН

Electrophysical properties of meso-porous silicon free standing films modified with palladium

Resistivity and complex impedance voltage dependences for thick mesoporous silicon free layers were studied in this work. The asymmetrical by the sign of applied voltage experimental curves at low frequencies have been obtained. Modification of electrophysical properties due to introduction of palladium particles into the porous matrix is observed. Impedance change regularities during oxidation of the samples have been measured. The explanation of experimental results by asymmetrical distribution of charge carrier traps in the bulk of porous silicon has been suggested. Energy band diagrams and charge transfer mechanisms of these heterostructures are discussed

Instanton propagator and instanton induced processes in scalar model

The propagator in the instanton background in the $(- \lambda \phi^{4})$ scalar model in four dimensions is studied.Leading and sub-leading terms of its asymptotics for large momenta and its on-shell double residue are calculated analytically. These results are applied to the analysis of the initial-state and initial-final-state corrections and the calculation of the next-to-leading (propagator) correction to the exponent of the cross section of instanton induced multiparticle scattering processes.Comment: 44 pages, 7 postscript figures, LaTe

Instabilities in the two-dimensional cubic nonlinear Schrodinger equation

The two-dimensional cubic nonlinear Schrodinger equation (NLS) can be used as a model of phenomena in physical systems ranging from waves on deep water to pulses in optical fibers. In this paper, we establish that every one-dimensional traveling wave solution of NLS with trivial phase is unstable with respect to some infinitesimal perturbation with two-dimensional structure. If the coefficients of the linear dispersion terms have the same sign then the only unstable perturbations have transverse wavelength longer than a well-defined cut-off. If the coefficients of the linear dispersion terms have opposite signs, then there is no such cut-off and as the wavelength decreases, the maximum growth rate approaches a well-defined limit.Comment: 4 pages, 4 figure