Determination of the propellant combustion law under ballistic experiment conditions

The main characteristics of ballistic experiment are the maximum pressure in the combustion chamber P max and the projectile velocity at the time of barrel leaving U M. During the work the burning law of the new high-energy fuel was determined in a ballistic experiment. This burning law was used for a parametric study of depending P max and U M from a powder charge mass and a traveling charge at initial temperature of + 20 °C was carried out. The optimal conditions for loading were obtained for improving the muzzle velocity by 14.9 %. Under optimal loading, there is defined the conditions, which is possible to get the greatest value muzzle velocity projectile at pressures up to 600 MPa

Mathematical model and software for investigation of internal ballistic processes in high-speed projectile installations

This paper describes a software package that allows to explore the interior ballistics processes occurring in a shot scheme with bulk charges using propellant pasty substances at various loading schemes, etc. As a mathematical model, a model of a polydisperse mixture of non-deformable particles and a carrier gas phase is used in the quasi-one-dimensional approximation. Writing the equations of the mathematical model allows to use it to describe a broad class of interior ballistics processes. Features of the using approach are illustrated by calculating the ignition period for the charge of tubular propellant

On the Wigner function of the relativistic finite-difference oscillator in an external field

The phase-space representation for a relativistic linear oscillator in a homogeneous external field expressed through the finite-difference equation is constructed. Explicit expressions of the relativistic oscillator Wigner quasi-distribution function for the stationary states as well as of states of thermodynamical equilibrium are obtained and their correct limits are shown.Comment: 12 pages, 6 figures, IOP styled LaTeX, to be published in Journal of Physics

Национальный атлас Арктики: структура и этапы разработки

On the instructions of President and Government of the Russian Federation, works for development of National Atlas of Arctic are started in the country. In this article the authors present their ideas from viewpoint of geographers who are well experienced in the field of cartographic works. A structure of future Atlas and lines of approaches to its development are proposed. The totality of experiences of preparation of other geographical atlases in both, the USSR and Russia, as well as the latest achievements of cartography, aerospace sources and GIS-technologies are recommended to be used. The National Atlas of Arctic is understood as a collection of knowledge of spatial-temporal information about geographical, ecological, economic, historical-ethnographic, cultural and social features of the Arctic. This cartographic model of the territory is designed for using in a wide range of scientific, managing, economic, defensive and social activities. A hard copy of the atlas is intended to be used as scientific-reference publication while its electronic version will make it possible to renovate its content and to improve it by means of actualization according to various directions of its practical use 16 sections proposed in a draft of the Atlas content are as follows: introductory, geological structure, relief, mineral resources, environment evolution, climate, land waters, seas, seashores, snow cover, glaciers, permafrost, soils, flora and fauna, state of the environment and the Nature protection, population, economics, and prospects for future. The popular-scientific edition of the Atlas is intended for use by wide circle of readers and also as a textbook for all levels of education. Presentation of material in the Atlas should combine a high scientific level and accessible language. In a popular form it will clarify traditions of careful treatment to the Nature and the nature-protective ethics of religious confessions of local people. Touristic maps will serve as guides for the Arctic with its bio-landscape and cultural diversity. Content of the Atlas should meet requirements of education standard in the field of geography. Ten sections are proposed for this version of the Atlas: introductory, geological structure, relief and resources, climate, permafrost and glaciers, land waters, seas of the Russian part of the Arctic, its flora and fauna, soils, population and economics, and conclusion Scientific and social results of the Atlas publication together with editorial and advertizing effects are demonstrated. Proposals for a format, scales of maps and type of edition are given, and potential participants of this project are indicated. Обосновывается необходимость создания Национального атласа Арктики. Приводится научно-справочный вариант издания с детальной характеристикой разделов атласа. Предлагается также его научно-популярный вариант, предназначенный для широкого круга пользователей, в том числе как пособие для всех уровней просвещения: от школ и вузов до общественных и государственных организаций, бизнес-школ, курсов повышения квалификации. Отмечается возможность создания системы поддержки принятия управленческих решений, основываясь на материалах научно-справочной версии Национального атлас

Endoscopic treatment for bulbar-membranous urethral obliteration: evaluation of the efficacy and safety

Introduction. The problem of endoscopic treatment for urethral strictures and obliterations remains unresolved. It is necessary to note that the effectiveness depends not only on the right indications, but also on the surgical technique and the study of the postoperative period management.Objective. To evaluate the efficacy and safety of endoscopic treatment of patients with bulbar-membranous urethral obliteration.Materials and methods. The study included 103 patients aged 20 to 89 years with bulbar-membrane urethral obliteration, who, for some reason or another, cannot perform urethroplasty. The patients underwent endoscopic recanalization of the urethra under X-ray control with further circular transurethral electroresection (TUR) of the scar tissues in the urethral obliteration zone (after 6 – 7 days).Results. The average age of the patients was 61.1 ± 18.3 years. After the operation, self-urination was restored in all patients. The average maximum urine flow rate (Q max) before discharge from the hospital was 12.6 ± 0.5 ml/s. Throughout the follow-up period, Q max tended to increase and at the end of the study (36 months) reached values of 16.5 ± 0.5 ml/s. During the first year of follow-up, 18 (17.5%) patients developed recurrent urethral stricture. Seventeen (16.5%) patients underwent repeated circular TUR of scar tissue in the zone of recurrent stricture. The effectiveness of the treatment was 90.0%.Conclusion. Endoscopic urethral recanalization followed by TUR of scar tissue in the obliteration zone is an effective and safe method in the treatment of bulbar-membranous urethral obliteration with length less than 1.0 cm

Effect of Initial Disturbance on The Detonation Front Structure of a Narrow Duct

The effect of an initial disturbance on the detonation front structure in a narrow duct is studied by three-dimensional numerical simulation. The numerical method used includes a high resolution fifth-order weighted essentially non-oscillatory scheme for spatial discretization, coupled with a third order total variation diminishing Runge-Kutta time stepping method. Two types of disturbances are used for the initial perturbation. One is a random disturbance which is imposed on the whole area of the detonation front, and the other is a symmetrical disturbance imposed within a band along the diagonal direction on the front. The results show that the two types of disturbances lead to different processes. For the random disturbance, the detonation front evolves into a stable spinning detonation. For the symmetrical diagonal disturbance, the detonation front displays a diagonal pattern at an early stage, but this pattern is unstable. It breaks down after a short while and it finally evolves into a spinning detonation. The spinning detonation structure ultimately formed due to the two types of disturbances is the same. This means that spinning detonation is the most stable mode for the simulated narrow duct. Therefore, in a narrow duct, triggering a spinning detonation can be an effective way to produce a stable detonation as well as to speed up the deflagration to detonation transition process.Comment: 30 pages and 11 figure

Chlamydia psittaci st24: clonal strains of one health importance dominate in Australian horse, bird and human infections

Chlamydia psittaci is traditionally regarded as a globally distributed avian pathogen that can cause zoonotic spill-over. Molecular research has identified an extended global host range and significant genetic diversity. However, Australia has reported a reduced host range (avian, horse, and human) with a dominance of clonal strains, denoted ST24. To better understand the widespread of this strain type in Australia, multilocus sequence typing (MLST) and ompA genotyping were applied on samples from a range of hosts (avian, equine, marsupial, and bovine) from Australia. MLST confirms that clonal ST24 strains dominate infections of Australian psittacine and equine hosts (82/88; 93.18%). However, this study also found novel hosts (Australian white ibis, King parrots, racing pigeon, bovine, and a wallaby) and demonstrated that strain diversity does exist in Australia. The discovery of a C. psittaci novel strain (ST306) in a novel host, the Western brush wallaby, is the first detection in a marsupial. Analysis of the results of this study applied a multidisciplinary approach regarding Chlamydia infections, equine infectious disease, ecology, and One Health. Recommendations include an update for the descriptive framework of C. psittaci disease and cell biology work to inform pathogenicity and complement molecular epidemiologySusan I. Anstey, Vasilli Kasimov, Cheryl Jenkins, Alistair Legione, Joanne Devlin, Jemima Amery-Gale ... et al

Introduction : The Pan-Eurasian Experiment (PEEX) - multidisciplinary, multiscale and multicomponent research and capacity-building initiative

The Pan-Eurasian Experiment (PEEX) is a multidisciplinary, multiscale and multicomponent research, research infrastructure and capacity-building program. PEEX has originated from a bottom-up approach by the science communities and is aiming at resolving the major uncertainties in Earth system science and global sustainability issues concerning the Arctic and boreal pan-Eurasian regions, as well as China. The vision of PEEX is to solve interlinked, global grand challenges influencing human well-being and societies in northern Eurasia and China. Such challenges include climate change; air quality; biodiversity loss; urbanization; chemicalization; food and freshwater availability; energy production; and use of natural resources by mining, industry, energy production and transport sectors. Our approach is integrative and supra-disciplinary, recognizing the important role of the Arctic and boreal ecosystems in the Earth system. The PEEX vision includes establishing and maintaining long-term, coherent and coordinated research activities as well as continuous, comprehensive research and educational infrastructure and related capacity-building across the PEEX domain. In this paper we present the PEEX structure and summarize its motivation, objectives and future outlook.Peer reviewe

Overview: Recent advances in the understanding of the northern Eurasian environments and of the urban air quality in China – a Pan-Eurasian Experiment (PEEX) programme perspective

The Pan-Eurasian Experiment (PEEX) Science Plan, released in 2015, addressed a need for a holistic system understanding and outlined the most urgent research needs for the rapidly changing Arctic-boreal region. Air quality in China, together with the long-range transport of atmospheric pollutants, was also indicated as one of the most crucial topics of the research agenda. These two geographical regions, the northern Eurasian Arctic-boreal region and China, especially the megacities in China, were identified as a “PEEX region”. It is also important to recognize that the PEEX geographical region is an area where science-based policy actions would have significant impacts on the global climate. This paper summarizes results obtained during the last 5 years in the northern Eurasian region, together with recent observations of the air quality in the urban environments in China, in the context of the PEEX programme. The main regions of interest are the Russian Arctic, northern Eurasian boreal forests (Siberia) and peatlands, and the megacities in China. We frame our analysis against research themes introduced in the PEEX Science Plan in 2015. We summarize recent progress towards an enhanced holistic understanding of the land–atmosphere–ocean systems feedbacks. We conclude that although the scientific knowledge in these regions has increased, the new results are in many cases insufficient, and there are still gaps in our understanding of large-scale climate–Earth surface interactions and feedbacks. This arises from limitations in research infrastructures, especially the lack of coordinated, continuous and comprehensive in situ observations of the study region as well as integrative data analyses, hindering a comprehensive system analysis. The fast-changing environment and ecosystem changes driven by climate change, socio-economic activities like the China Silk Road Initiative, and the global trends like urbanization further complicate such analyses. We recognize new topics with an increasing importance in the near future, especially “the enhancing biological sequestration capacity of greenhouse gases into forests and soils to mitigate climate change” and the “socio-economic development to tackle air quality issues”