On the Cholesky Decomposition for electron propagator methods: General aspects and application on C60

To treat the electronic structure of large molecules by electron propagator methods we developed a parallel computer program called P-RICD$\Sigma$. The program exploits the sparsity of the two-electron integral matrix by using Cholesky decomposition techniques. The advantage of these techniques is that the error introduced is controlled only by one parameter which can be chosen as small as needed. We verify the tolerance of electron propagator methods to the Cholesky decomposition threshold and demonstrate the power of the P-RICD$\Sigma$ program for a representative example (C60). All decomposition schemes addressed in the literature are investigated. Even with moderate thresholds the maximal error encountered in the calculated electron affinities and ionization potentials amount to a few meV only, and the error becomes negligible for small thresholds.Comment: 30 pages, 6 figures submitted to J.Chem. Phy

Effect of pre-strain rolling path on abnormal grain growth in friction-stir welded AL-MG-SI alloy

The fine-grained microstructures evolved during friction stir welding of aluminum alloys often exhibit abnormal grain growth during post-weld heat treatment. To avoid this undesirable phenomenon, a pre-strain rolling approach has been employed in the present stud

On the local variation of mechanical properties in friction-stir welded 6061 aluminum alloy

In this work, digital image correlation technique was applied to investigate local variations of mechanical properties in friction-stir welded 6061 aluminium alloy. A pronounced strain concentration in the bottom section of stir zone was revealed during transverse tensile tests. This effect was suggested to be associated with residual stress generated in this microstructural region during friction-stir weldin

Grain structure evolution during friction-stir welding of 6061-T6 aluminum alloy

In this work, electron backscattered diffraction (EBSD) was used to examine theevolution of the grain structure during friction stir welding of aluminum alloy 6061-T6. In the entire FSW range studied, the microstructure evolution was found to be governed by continuous recrystallization. An increase in the welding temperature resulted only in microstructural coarsenin

Morphological estimation of changes in cancellous raduis bone for forensic age determination

Visual researches showed that the cancellous bone of the distal radius has significant morphological changes with the increase of years. Revealed structural changes of cancellous bone allows to differentiate the age of an object and to direct a medical expert towards the proposed age group at the identification study. As a result of photocolorimetric research of involution changes of cancellous bone of the distal radius we found statistically significant increase of light transmission with the increase of years which is associated with an increase of osteoporosis. The correlation coefficient ranged from 0,63 to 0,80. On the basis of these data mathematical models that allow to determine the person's age in the forensic identification researches of the distal radius were developed (standard mean square error in determination of the age was from 6,6 to 8,2 years)

Inter-year variation in pup production of Caspian seals (Pusa caspica) 2005-2012 determined from aerial surveys

Assessing species abundance and reproductive output is crucial for evaluations of population dynamics, conservation status and the development of management objectives. The Caspian seal (Pusa caspica) is a key predator in the Caspian Sea ecosystem and is listed as “Endangered” by IUCN. Here we report on fixed-wing aerial strip transect surveys of the breeding population on the Caspian Sea winter ice field carried out in February 2005-2012. Potential detection biases were estimated by applying a Petersen mark-recapture estimator to the counts from double photographic observations. We also tested for effects of weather conditions on count results, and for correlations between pup production and ice conditions and net primary productivity (npp). Fluctuations in pup production estimates were observed among years, ranging from 8,200 pups (95% CI 7,130-9342) in 2010 to 34,000 (95% CI 31,275-36,814) in 2005. Total adults on the ice ranged from 14,500 in 2010 to 66,300 in 2012. We did not detect significant associations between pup production and either ice summary data (ice season length, and ice area) or npp. The observed inter-year variation may be partly due to underlying biological drivers influencing the fecundity of the population, although measurement errors arising from observation bias, plus variation in survey timing and weather conditions may also have contributed. Identifying the potential drivers of Caspian seal population dynamics will require extending both the survey time series and the quality of supporting data. However, inter-year fluctuations should still cause concern that the population may be vulnerable to environmental variability and ecosystem dynamics

Microstructure-strength relationship in friction-stir welded 6061-T6 aluminum alloy

In this work, a structural response of 6061-T6 aluminum alloy to friction-stir welding (FSW) was studied in wide range of processing conditions in order to establish a better foundation for the microstructure-strength relationship in produced welds. In contrast to the widely-accepted conception of the FSW-induced precipitation behavior, the welding temperature was found to be often below the dissolution threshold and thus no particle dissolution took plac

Regularities of structural-cellular structure of ovaries in ontogenesis

The article presents the examination of the ovaries of embryos, ovaries of human feti and ovaries of children of the tender age. The researches revealed the increase of the surface of follicles, nucleus and primary oocyte's cytoplasm that tells about the fact that further follicular maturation continues in the ovaries of a child of 2-4 months old. Also we registered the increase of nuclear cytoplasmic ratio, appearance of single mature follicles with cumulus oophorus that testifies to the fact that the ovary is functionally mature. Furthermore the research revealed increased content of lipids and DNA in follicular epithelium that also tells aboutfunctional maturity of the ovary. It was found that incretory activity of an ovary during the first year of life is provided by the cells originated from the connective tissue membrane of atresic follicles

Analysis of doctors’ appeals on the issues of countering doping in sports

Objective: the main topics of the doctors’ questions were the preparation of medical documents for a TUE application, the determination of the anti­doping status of various substances and methods, as well as the use of dietary supplements in sports.Materials and methods: an analysis was carried out of more than 400 appeals of doctors providing medical assistance to athletes of various levels on the issues of countering doping in sports. The aim of the work was to identify ways to improve educational and informational activities aimed at improving the quality of medical documents for TUE applications.Results: the need for continuous work to improve the level of doctors’ knowledge in countering doping in sports was confirmed, including clarification of the procedure for using documents from anti­doping organizations, the need to use TUE guidelines for physicians and the specifics of prescribing substances prohibited only during the competitive period