Совершенствование методики тренировки гиревиков 18-20 лет на этапе спортивного совершенствования

Совершенствование методики тренировки гиревиков 18-20 лет на этапе спортивного совершенствованияImprovement of techniques weightlifters 18-20 years at a stage of sports perfectio

Study of the microstructure resulting from brazed aluminium materials used in heat exchangers

Re-solidification of AA4343 cladding after brazing as well as the related precipitation in the modified AA3003 core material have been investigated. Analysis of the re-solidified material showed that partial dissolution of the core alloy occurs in both the brazing joints and away of them. Far from the brazing joints, the dissolution is, however, limited and diffusion of silicon from the liquid into the core material leads to solid-state precipitation in the so-called “band of dense precipitates” (BDP). On the contrary, the dissolution is enhanced in the brazing joint to such an extent that no BDP could be observed. The intermetallic phases present in the resolidified areas as well as in the core material have been analyzed and found to be mainly cubic alpha-Al(Mn,Fe)Si. These results were then compared to predictions made with available phase diagram information

Numerical evolution of multiple black holes with accurate initial data

We present numerical evolutions of three equal-mass black holes using the moving puncture approach. We calculate puncture initial data for three black holes solving the constraint equations by means of a high-order multigrid elliptic solver. Using these initial data, we show the results for three black hole evolutions with sixth-order waveform convergence. We compare results obtained with the BAM and AMSS-NCKU codes with previous results. The approximate analytic solution to the Hamiltonian constraint used in previous simulations of three black holes leads to different dynamics and waveforms. We present some numerical experiments showing the evolution of four black holes and the resulting gravitational waveform.Comment: Published in PR

Study of errors in the integration of the two-body problem using generalized Sundman's anomalies

[EN] As is well known, the numerical integration of the two body problem with constant step presents problems depending on the type of coordinates chosen. It is usual that errors in Runge-Lenz's vector cause an artificial and secular precession of the periaster although the form remains symplectic, theoretically, even when using symplectic methods. Provided that it is impossible to preserve the exact form and all the constants of the problem using a numerical method, a possible option is to make a change in the variable of integration, enabling the errors in the position of the periaster and in the speed in the apoaster to be minimized for any eccentricity value between 0 and 1. The present work considers this casuistry. We provide the errors in norm infinite, of different quantities such as the Energy, the module of the Angular Moment vector and the components of Runge-Lenz's vector, for a large enough number of orbital revolutions.Lopez Orti, JA.; Marco Castillo, FJ.; Martínez Uso, MJ. (2014). Study of errors in the integration of the two-body problem using generalized Sundman's anomalies. SEMA SIMAI Springer Series. 4:105-112. doi:10.1007/978-3-319-06953-1_11S1051124Brower, D., Clemence, G.M.: Celestial Mechanics. Academic, New York (1965)Brumberg, E.V.: Length of arc as independent argument for highly eccentric orbits. Celest. Mech. 53, 323–328 (1992)Fehlberg, E., Marsall, G.C.: Classical fifth, sixth, seventh and eighth Runge–Kutta formulas with stepsize control. Technical report, NASA, R-287 (1968)Ferrándiz, J.M., Ferrer, S., Sein-Echaluce, M.L.: Generalized elliptic anomalies. Celest. Mech. 40, 315–328 (1987)Gragg, W.B.: Repeated extrapolation to the limit in the numerical solution of ordinary differential equations. SIAM J. Numer. Anal. 2, 384–403 (1965)Janin, G.: Accurate computation of highly eccentric satellite orbits. Celest. Mech. 10, 451–467 (1974)Janin, G., Bond, V.R.: The elliptic anomaly. Technical memorandum, NASA, n. 58228 (1980)Levallois, J.J., Kovalevsky, J.: Géodésie Générale, vol. 4. Eyrolles, Paris (1971)López, J.A., Agost, V., Barreda, M.: A note on the use of the generalized Sundman transformations as temporal variables in celestial mechanics. Int. J. Comput. Math. 89, 433–442 (2012)López, J.A., Marco, F.J., Martínez, M.J.: A study about the integration of the elliptical orbital motion based on a special one-parametric family of anomalies. Abstr. Appl. Anal. 2014, ID 162060, 1–11 (2014)Nacozy, P.: The intermediate anomaly. Celest. Mech. 16, 309–313 (1977)Sundman, K.: Memoire sur le probleme des trois corps. Acta Math. 36, 105–179 (1912)Tisserand, F.F.: Traité de Mecanique Celeste. Gauthier-Villars, Paris (1896)Velez, C.E., Hilinski, S.: Time transformation and Cowell’s method. Celest. Mech. 17, 83–99 (1978

Characterization of a new metallo-β-lactamase gene, blaNDM-1, and a novel erythromycin esterase gene carried on a unique genetic structure in klebsiella pneumoniae sequence Type 14 from India

A Swedish patient of Indian origin traveled to New Delhi, India, and acquired a urinary tract infection caused by a carbapenem-resistant Klebsiella pneumoniae strain that typed to the sequence type 14 complex. The isolate, Klebsiella pneumoniae 05-506, was shown to possess a metallo-β-lactamase (MBL) but was negative for previously known MBL genes. Gene libraries and amplification of class 1 integrons revealed three resistance-conferring regions; the first contained blaCMY-4 flanked by ISEcP1 and blc. The second region of 4.8 kb contained a complex class 1 integron with the gene cassettes arr-2, a new erythromycin esterase gene; ereC; aadA1; and cmlA7. An intact ISCR1 element was shown to be downstream from the qac/sul genes. The third region consisted of a new MBL gene, designated blaNDM-1, flanked on one side by K. pneumoniae DNA and a truncated IS26 element on its other side. The last two regions lie adjacent to one another, and all three regions are found on a 180-kb region that is easily transferable to recipient strains and that confers resistance to all antibiotics except fluoroquinolones and colistin. NDM-1 shares very little identity with other MBLs, with the most similar MBLs being VIM-1/VIM-2, with which it has only 32.4% identity. As well as possessing unique residues near the active site, NDM-1 also has an additional insert between positions 162 and 166 not present in other MBLs. NDM-1 has a molecular mass of 28 kDa, is monomeric, and can hydrolyze all β-lactams except aztreonam. Compared to VIM-2, NDM-1 displays tighter binding to most cephalosporins, in particular, cefuroxime, cefotaxime, and cephalothin (cefalotin), and also to the penicillins. NDM-1 does not bind to the carbapenems as tightly as IMP-1 or VIM-2 and turns over the carbapenems at a rate similar to that of VIM-2. In addition to K. pneumoniae 05-506, blaNDM-1 was found on a 140-kb plasmid in an Escherichia coli strain isolated from the patient's feces, inferring the possibility of in vivo conjugation. The broad resistance carried on these plasmids is a further worrying development for India, which already has high levels of antibiotic resistance