Physical Processes of Generating Electric and Magnetic Fields in the Channel of СО2-Laser Pulse Propagation

Russian Physics Journal - Mechanisms of generating electric and magnetic fields during propagation of microsecond CO2-laser pulses in the atmosphere along long paths are considered. The wavelength...     

Electrical Parameters of a Laser Beam Channel in the Atmosphere. I

Russian Physics Journal - Results of measurements of the conductivity in the laser radiation propagation channel not only in laboratory, but also outdoors for laser radiation focused in the free...     

Remote Detection of Asymmetric Dimethylhydrazine in the Atmosphere

The possibility of remote atmospheric detection of an ecotoxicant (asymmetric dimethylhydrazine) by means of a fluorescing mark is considered. The effect of asymmetric dimethylhydrazine on the spectral-luminescent properties of rhodamine 6G, nonsubstituted rhodamine, and amino- and hydroxysubstituted derivative of phenalenone is studied. It is shown that the molecules containing amino groups change their spectral properties and lose emitting properties in the presence of dimethylhydrazine. The hydroxysubstituted derivative of phenalenone in dimethylhydrazine generates laser radiation when pumped by a Nd:YAG-laser and shows the stimulated fluorescence effect in aerosols.     

Calibration of a holographic disdrometer

The factors giving rise to error in the determination of microparticle size from an image-plane holographic disdrometer are examined. A method of calibration is proposed and experimentally confirmed that lowers the average error to 10%.Tomsk University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 94–97, May, 1992.     

Chemiluminescence determination of the in vivo and in vitro antioxidant activity of RoseOx and carnosic acid

Lipid free-radical oxidation has been studied in vivo in the mitochondrial fractions of the liver of rats fed RoseOx (carnosic acid nutritional supplement) by measuring chemiluminescence. The kinetics of the lipid chemiluminescence in rats fed RoseOx are significantly different from those of the control. The intensity of the chemiluminescence fast flash decreases by 45% (p < 0.01), which indicates a reduction of lipid peroxides. The time between fast and slow flashes increases by 96% (p < 0.05), which indicates a higher content of antioxidants in the lipid membrane. The in vitro experiments in rat liver mitochondrial fraction display more effective antioxidant action of alpha-tocopherol in 1 microM concentration than 1 microM carnosic acid by an increase of the time between fast and slow chemiluminescence flashes (p < 0.01). However, the higher antioxidant activity of 1 microM carnosic acid by a decrease of intensity of the chemiluminescence fast (p < 0.05) and slow (p < 0.05) flashes in comparison with alpha-tocopherol is revealed in these experimental conditions in vitro. Carnosic acid has antioxidant effects on homogeneous oxidation in vitro as well. The chemiluminescence of methyl oleate initiated by 2,2'-azobis(2-methylpropionitrile) decreases by 25% (p < 0.01) in the presence of 13.5 microM carnosic acid. 13.5 microM alpha-tocopherol decreases the methyl oleate chemiluminescence by 45%. A higher antioxidant activity of alpha-tocopherol in comparison with carnosic acid (p < 0.001) is found in this system. These results indicate that RoseOx reduces free-radical-induced lipid peroxidation in vivo. In vitro data show that carnosic acid has direct action as an antioxidant, rather than as a membrane-structure modifier.     

Electrical Parameters of a Laser Beam Channel in the Atmosphere. II

Russian Physics Journal - Results of measurements of the conductivity and electric field strength in the laser radiation propagation channel and near it are presented. An experimental setup and...     

Energy Parameters and Spectral Characteristics of Lasing of a Liquid Dye Drop Incorporating Nanoparticles

The spectral characteristics and the energy parameters of the fluorescence of a liquid rhodamine-6G dye drop incorporating suspended TiO₂ nanoparticles are presented. It is demonstrated that the lasing threshold for modes of the whispering gallery of liquid dye drops is halved in the presence of nanoparticles.     

A decrease in the superluminescence threshold of composites of an organic dye with nanoparticles

It is established that admixture of Ag, Al, Cu, Ni, Zn, and Fe ₃ O ₄ nanoparticles to a rhodamine 6G solution in ethanol with a concentration of 10⁻² mol/L that fills a cell with a thickness of 600 μm results in a decrease in the superluminescence thresholds by no less than 50 folds. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 77–82, September, 2008.