2,000 research outputs found
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
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
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
Collective and fractal properties of pion jets in the four-velocity space at intermediate energies
Experimental results are presented for study of collective and fractal
properties of soft pion jets in the space of relative four-dimensional
velocities. Significant decreasing is obtained for mean square of second
particle distances from jet axis for pion-proton interactions at initial
energies GeV in comparison with hadron-nuclear collisions at close
energies. The decreasing results in power dependence of distance variable on
collision energy for range GeV. The observation allows us to
estimate the low boundary of manifestation of color degree of freedom in pion
jet production. Cluster dimension values were deduced for pion jets in various
reactions. Fractional values of this dimension indicate on the manifestation of
fractal-like properties by pion jets. Changing of mean kinetic energy of jet
particles and fractal dimension with initial energy increasing is consistent
with suggestion for presence of color degrees of freedom in pion jet production
at intermediate energies.Comment: The conference "Physics of fundamental interactions". ITEP, Moscow,
Russia. November 23 - 27, 200
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