Investigation of the conditions of efficient I*<Subscript>2</Subscript> (342 nm) luminescence in a barrier discharge in a Kr-I<Subscript>2</Subscript> mixture

The energy and spectral characteristics of a barrier discharge in a mixture of iodine vapor with krypton have been investigated theoretically and experimentally. The emission spectrum consists of the single I*₂ molecular band D′ → A′ peaking at 342 nm, the iodine resonance line at 206.2 nm, and the group of bands corresponding to iodine emission. The highest intensity of the I*₂ (342 nm) band was obtained at a mixture pressure near 450 Torr. A mean output power and an efficiency of 550 mW and 1.6%, respectively, have been achieved. It is shown that, for the I₂ barrier-discharge excilamp, the homogeneous, rather than filamentary form of discharge glow is optimal from the viewpoint of the highest mean output power. The maximal calculated value of the emission efficiency for the 342-nm band was 5%. The main processes determining energy losses in plasma have been found, and ways to increase the efficiency of emission in the D′ → A′ band of the I*₂ molecule have been proposed.     

Phenomenon of apokamp discharge

A new phenomenon has been discovered where a bend of a plasma channel becomes of a source of one or several diffuse jets that have a length (at a given voltage) up to 4–6 cm and are directed across the plasma channel at a pulse-periodic spark discharge in air under normal conditions. The phenomenon is called apokamp discharge (apokamp). The spectrum of radiation of the apokamp includes primarily the bands of electron-vibrational transitions of the second positive system of molecular nitrogen. The conditions of the formation of apokamp have been experimentally revealed and it has been established that it consists of plasma bunches moving from the plasma channel at each pulse at a velocity of about 220 km/s.     

Source of an atmospheric-pressure plasma jet formed in air or nitrogen under barrier discharge excitation

We analyzed the atmospheric pressure plasma jet excited in air and nitrogen by a barrier discharge. The source forming stable plasma jets of length up to 4 cm in air and nitrogen is constructed, and its energy and spectral characteristics are measured.     

Methanol photomineralization in a Xe2 photoreactor (λ = 172 nm) with aeration of a solution

It is demonstrated that mineralization of methanol in a water solution in a Xe₂* photoreactor (λ ∼ 172 nm) upon exposure to vacuum ultraviolet radiation with aeration allows the process to be to intensified and the exposure time to be reduced by several times. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 95–97, October, 2006.     

Centrifugal enrichment of sulfur isotopes

This work contains the results of the research for the complete cycle of the centrifuge enrichment process of all sulfur isotopes. As a result of this work there was obtained, and made available (by centrifuge enrichment process), for the first time hundreds of grams of all the isotopes of sulfur to high enrichment.     

Phototransformations of Phenols in Aqueous Solutions under Different Excitation Modes

The photolysis of aqueous solutions of two widespread environmental organic ecotoxicants—phenol and 4-chlorophenol—on excitation by UV radiation from a KrCl exciplex laser and a glow-discharge KrCl excilplex lamp was studied. The irradiated solutions were studied by spectroscopic techniques. The laser and lamp photolyses were compared.     

Neutron yields from massive lead and uranium targets irradiated with relativistic protons

Long-lived isotopes can be transmuted into stable or short-lived elements either by neutron captures or neutron induced fission. The need of a large excess of neutrons has led to the use of accelerator driven sources (ADS). A series of experiments were carried out at the Synchrophasotron/Nuclotron of the Joint Institute for Nuclear Research (JINR) Dubna, using protons of 1.0 GeV. Solid Lead and Uranium targets surrounded by paraffin moderator were irradiated. On the outer surface of the moderator a number of Solid State Track Detectors were placed to monitor neutron spatial distribution. The results showed that the maximum neutron production was reached within the range of one to two proton mean free paths in the target. Then decreasing neutron production follows the proton beam attenuation along the target. Moreover, the results showed both targets neutron production evolution along the target, to be the same. However, neutron flux per incident proton is depended on the target mass, which was found to be higher for the heavier target.     

Determining the energy balance in barrier-discharge Xe<Subscript>2</Subscript> excilamp by the pressure jump method

The energy redistribution in barrier-discharge Xe₂ excilamp in various excitation regimes is investigated using the pressure jump method. Analytic expressions are derived for calculating power W dissipated in the excilamp discharge plasma in the form of heat and for calculating total discharge heat power P_T spent on heating the excilamp. It is shown that the mechanism of the thermal energy dissipation gradually changes upon an increase in the xenon pressure in the excilamp. The conditions for generating the maximal radiation power of the excilamp are determined. It is shown that the maximum of the average radiation power is attained for an excitation pulse duration of 500 ns and the maximal pulse power is attained for a pulse duration of 100 ns. It is found that the optimal operation regime for the excilamp corresponds to the maximal values of the P_T–W difference.     

Mathematical Modeling of Some Applied Problems in Haemodynamics

The present study discusses some basic issues of mathematical modeling in medicine and describes examples of specific results of analytical and numerical investigations in haemodynamics. It briefly describes a method for constructing exact solutions of the linearized equations of haemodynamics on a graph, an analysis of these solutions, and a particular application of the proposed theory for solving practical medical problems. A number of nonspecific aortoarteritis syndromes are simulated. Examples of mathematical modeling of blood flow in the systemic circulatory circuit under the action of a periodically contracting heart are presented. These examples reproduce some of the main physiological regularities of the circulatory system as a whole. One of the applications of mathematical modeling in haemodynamics includes the stealing of cerebral blood supply during a temporary occlusion of the subclavian artery.