Mathematical modelling of the spread of contamination during fires in forests exposed to radioactive contamination

The paper suggested in the context of the general mathematical model of forest fires [1] gives a new mathematical setting and method of numerical solution of a problem of a radioactive spread above the forest region. Numerical solution of problems of radioactive smoke spread during crown fire in exemplified heat energy release in the forest fire front was found. Heat energy release in the forest fire front was found to cause further radioactive particles spread by the action of wind. In the absence of wind, radioactive smoke particles deposit again on the underlying surface after a time. As a wind velocity increases, these particles are transferred in the ground layer over distances proportional to a wind velocity

Vortex-chain phases in layered superconductors

Layered superconductors in tilted magnetic field have a very rich spectrum of vortex lattice configurations. In the presence of in-plane magnetic field, a small c-axis field penetrates in the form of isolated vortex chains. The structure of a single chain is mainly determined by the ratio of the London [$\lambda$] and Josephson [$\lambda_{J}$] lengths, $\alpha= \lambda/\lambda_{J}$. At large $\alpha$ the chain is composed of tilted vortices [tilted chains] and at small $\alpha$ it consists of a crossing array of Josephson vortices and pancake stacks [crossing chains]. We studied the chain structures at intermediate $\alpha$'s and found two types of behavior. (I) In the range $0.4 < \alpha < 0.5$ a c-axis field first penetrates in the form of pancake-stack chains located on Josephson vortices. Due to attractive coupling between deformed stacks, their density jumps from zero to a finite value. With further increase of the c-axis field the chain structure smoothly evolves into modulated tilted vortices and then transforms via a second-order phase transition, into the tilted straight vortices. (II) In the range $0.5 < \alpha < 0.65$ a c-axis field first penetrates in the form of kinks creating kinked tilted vortices. With increasing the c-axis field this structure is replaced via a first-order phase transition by the strongly deformed crossing chain. This transition is accompanied by a large jump of pancake density. Further evolution of the chain structure is similar to the higher anisotropy scenario: it smoothly transforms back into the tilted straight vortices.Comment: Accepted to Phys. Rev. B, 20 pages 12 figures, animation of chain structure is available in http://mti.msd.anl.gov/movies/Chains/Nl8al06Im.gif (gif, 441 KB

Experimental study of the thermal stability of materials in high temperature oxygen-containing media

An experimental study is made of the interaction of several materials with a high temperature medium containing oxygen. The temperature of the surface was measured as a function of time. It is found that the higher the velocity of mass removal from the surface, the more effective is the material from the viewpoint of heat resistance

Lidar observations of atmospheric optical characteristics during Sichuan earthquake

The results of lidar observations of the atmosphere during the Sichuan (China) earthquake of 2008 are presented. It is shown that atmospheric parameters substantially changed during and after the earthquake. The profile of scattering characteristics formed in the lower troposphere differs from the original, which can serve as a predictor for earthquakes

Micro- and Nanocapillary Structures Based on Dielectric Materials to Focus the Ion Beams

The 255 keV and 150 keV proton beams transmission through tapered glass capillaries with 10 μm and 5 μm outlet diameters, respectively, were studied. The dependence of the output current on input current and the dependence of coefficient of proton beam transmission through capillary on the tilt angle of the capillary with respect to the beam axis were investigated. The focusing and guiding effects for transmitted proton beams were observed. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3521

Friendship and non-aggression treaty between the USSR and Yugoslavia

The article deals with the Soviet-Yugoslav relations on the eve of World War II, developed in adverse conditions. This was primarily due to the fact that the Yugoslav government headed by Cvetkovic had rapprochement to the Axis Powers. His trips together with the Minister of Foreign Affairs to Berchtesgaden, and later to Vienna led to Belgrade's accession to the Tripartite Pact. Rumors about the imminent catastrophe were spread immediately. Seeing that it is impossible to save the monarchical dictatorship, a group of Yugoslav generals and officers connected with the opposition bourgeois parties and the British Intelligence service decided to pre-empt the developments and eliminate the unpopular government. They staged a coup on March 27. The Regency Council headed by Prince Paul and pro-German cabinet of Cvetkovic-Macek was overthrown. The commander of the Yugoslav Air Force General Simovic headed the new government. It ran to signing of the Treaty of friendship and non-aggression with the Soviet Union, which has not entered into force as a result of German aggression against Yugoslavia.peer-reviewe

Soviet-hungarian economic and political relationships

In the document-based article is given the analysis of foreign policy of the USSR 1940-1941 which dwells on the Soviet-Hungarian relationships on the threshold of the Great Patriotic War. A special attention is paid to highlighting peaceful friendly aspirations – though bringing no positive results - of the Soviet Union in Hungarian direction. The document-based article underlines some facts discovering a dramatic character of Soviet-Hungarian relationships on the threshold of the Great Patriotic War – the war imposed by the Nazi Germany on the USSR. The details of negotiations between the USSR and Hungary in Budapest and Moscow are discovered; the role of politicians such as Molotov, Krishtoffi, Sharonov, Chaki, Vyshinsky is shown. The facts touching Hungarian interests in Romania and Yugoslavia before the war between Germany and the USSR are given. The details of negotiations about concluding a treaty on commerce between the USSR and Hungary are discussed. The motives of the Hungarian troops’ invasion to Yugoslavia are considered. A double-standard policy of Hungary under Khorti’s dictatorship, its proximity with the Nazi regime which influenced Hungary’s starting the war against the USSR are explained. The details on diplomacy policy of the Nazi Germany aimed at further plan-realization on occupying the territories of Eastern Europe are given.peer-reviewe