Lie group analysis for multi-scale plasma dynamics

An application of approximate transformation groups to study dynamics of a system with distinct time scales is discussed. The utilization of the Krylov-Bogoliubov-Mitropolsky method of averaging to find solutions of the Lie equations is considered. Physical illustrations from the plasma kinetic theory demonstrate the potentialities of the suggested approach. Several examples of invariant solutions for the system of the Vlasov-Maxwell equations for the two-component (electron-ion) plasma are presented.Comment: Latex, 15 pages, 7 figure. This is an enlarged contribution to Journal of Nonlinear Mathematical Physics v.18, Suppl. 1 (2011) p.163-175 with modest stylistic corrections introduced mainly in the third Sectio

Use of reinforcing elements to improve fatigue strength of steel structures of mine hoisting machines (MHM)

The article discusses the issues of fatigue fracture of steel structures and the method of increasing their strength through the use of reinforcing elements. The authors set the search for ways to improve steel structures and to reduce their metal intensity without reducing strength and increasing their resistance to fatigue failure, except for the use of expensive high-strength alloys. They have proposed a method for strengthening the structure and searching for its optimal shape of the loaded part, capable with a smaller wall thickness to withstand fatigue failure of steel structures of mine hoisting machines used to transport metallurgical coke in long-term operation. The results of computer modeling the stress-strain state of a steel beam under operating loads are given

Immunogenic and Protective Features of the Recombinant Vaccinia Virus Strain Expressing Cassette of Genes of Marburg Virus Structural Proteins

The aim of the study was to create a highly immunogenic vaccine construct based on a recombinant variant of a replication-defective MVA strain of vaccinia virus, expressing virus-like particles that mimic natural infection with Marburg virus. Materials and methods. The recombinant virus was obtained through recombination between homologous viral DNA sequences and the insertion plasmid pDel2-GP-VP-Pat which carries transgenes of the structural proteins GP and VP40 of Marburg virus, flanked by fragments of MVA strain genome. Structure of the recombinant virus was confirmed in PCR and using sequencing, transgenes expression was analyzed by Western blotting, viruslike particles formation was recorded using electron microscopy. Evaluation of immunogenicity and protectivity was carried out using a guinea pig model. The antibody titer was determined in enzyme-linked immunosorbent assay. To assess T-cell response, the intracellular staining of cytokines was used, followed by analysis of samples on a flow cytometer. Results and discussion. On the basis of highly attenuated MVA strain of vaccinia virus a recombinant variant MVA-GP-VP40-MARV has been constructed, carrying a cassette of transgenes, GP and VP40, of Marburg virus in the region of deletion II of the genome. The expression of transgenes in MVA-permissive CER cells infected with recombinant MVA-GP-VP40-MARV strain and secretion of GP and VP40 proteins into culture medium have been demonstrated. Electron microscopy analysis has revealed the presence of Marburg virus-like particles in the culture medium of cells 12 hours after infection. Double vaccination of guinea pigs with MVA-GP-VP40-MARV strain at a dose of 108 PFU/animal induced the formation of antibodies to Marburg and vaccinia viruses, as well as 100 % protection against lethal Marburg virus infection (50 LD50). Using original TEpredict software, the structure of T-helper epitopes of GP protein has been predicted. Using the ICS method, the biological activity of these epitopes has been experimentally confirmed and it was shown that they provide the induction of a T-cell immune response as part of the MVA-GP-VP40-MARV vaccine construct