Relation between the distribution of initiation sites of a discharge and the field nonuniformity at an electrode

The connection between the field nonuniformity at an electrode and the distribution of discharge initiation sites over its surface is described. The results of experiments on the breakdown of transformer oil in the cone-plane system of electrodes is analyzed within the framework of a multifractal model of the charge distribution [1]. The conclusion given in [1] that the regions with the maximum local field strength are not always the most probable sites for initiation of a discharge was experimentally confirmed. We observed the theoretically predicted transition of the discharge initiation sites at sharp points on the surface of a cone. For electrodes of stainless steel and transformer oil a value of the index relates the probability of initiation of a discharge to the local field strength was determined.Scientific — Research Institute of High Voltages at Tomsk Polytechnic Institute. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 32–35, April, 1995.     

Impulsive-discharge formation in water

This paper reports on research on an impulsive electrical discharge in deionized water (=2 × 10⁴ · m) in the voltage range 17–50 kV. The research showed that the discharge proceeds through the development of subsonic (U=17–22 kV) or supersonic (U=25–50 kV) streamers, depending on the electric-field strength at the surface of the tip. When voltage impulses having an amplitude of 20–25 kV are unleashed, the development of both types of streamers is observed in the discharge gap. The experiments carried out by the authors do not confirm the hydrodynamic origin of the disturbances at the initiating electrode that give rise to the discharge's development. The authors hypothesize that streamer development is due to the ionization of water molecules. The energy expenditures to ionize the molecules in the streamer channel are estimated.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 88–92, January, 1989.     

Polysaccharides of plant tissue cultures. III. Enzymatic hydrolysis of industrial wastes of the biomass of a ginseng tissue culture

Questions of the enzymatic hydrolysis of industrial wastes of the biomass of a ginseng tissue culture by Pektofoetidin P10× (I), Tsellyulaza P10× (II), and Tsellokoningin P10× (III) are discussed. The optimum conditions permitting the hydrolysis of the wastes by the following respective percentages have been selected: (I) 62; (II) 43; (III) 54. Subsequent treatment of the wastes with mineral acids raises the total degree of hydrolysis to 84–88%. The monocarbohydrate compositions of the hydrolysates have been studied by chromatographic methods. Student I. B. Smirnova took part in the work.     

Modification of the titrimetric method of analyzing pectin substances

A potentiometric variant of the titrimetric method of analyzing pectin substances has been developed which is distinguished by adequate accuracy and good reproducibility. The modified method has been tested on methyl (methyl 2,3-di-O-methyl-,-galactopyranosid)uronate and has been used for determining the free (K_f) and esterified (K_e) carboxy groups of the pectin substances of mint. The methods of isolating, purifying, and fractionating the pectin substances and determining their K_f and K_e values are given. Formulas are presented for calculating the percentage values of K_f and K_e.M. V. Frunze Simferopol' State University. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 428–431, July–August, 1984.     

Luminescence Investigations of the Effect of the Structure of the Molecules on their Stability during Interaction with Electrons in the Gas Phase

Journal of Applied Spectroscopy - By luminescence spectroscopy of the decomposition products during excitation by monochromatic electrons with various energies in the gas phase it was shown that...     

Interaction of pectin substances with copper,mercury, zinc,and cadmium salts

The interaction of the sage, mint, apple, and ginseng pectins, isolated from tissue culture wastes and purified with copper, mercury, zinc, and cadmium salts, has been studied by the amperometric method with two metal indicator electrodes. The optimum conditions of titration have been determined: pH 3.5–5.0; concentration of pectin substances 5·10^–5-1·10^–3 g/ml of solution. It has been established by graphical and mathematical methods that the interaction is accompanied by the formation of compounds with a ratio of the carboxy groups of pectins to the metal cation of two. The IR spectra of sage pectin and of copper and mercury pectinates are given.M. V. Frunze, Simferopol' State University. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 171–175, March–April, 1988.