A Gas-Discharge Plasma Source for the Modification of the Potential on the Surface of an Insulator

A gas-discharge source of low-temperature plasma with the charged particle concentration of 10¹¹–10¹³ m^–3 is described. The operating characteristics of the source are considered. Experiments showed that the developed plasma source can be effectively used for the soft (without breakdowns) neutralization of both surface and bulk excess charge accumulated by insulating materials.     

Numerical modeling of the detonation of a submerged hydrogen-air jet

Moscow. Translated from Fizika Goreniya i Vzryva, Vol. 26, No. 4, pp. 110–116, July–August, 1990.     

Electroflotation extraction of low-soluble copper compounds from PCB production flushing water

The influence of the internal phase nature and electrolyte solution on the electroflotation extraction of the low-soluble copper compounds from the PCB production flushing water of the electronic technology was specified. Electroflotation activity decreases in the series Cu(OH)₂, CuCO₃, Cu₃PO₄, CuS. The influence of the surfactants (SAT) on the kinetics of the electroflotation process, on the particle size of the internal phase and electrokinetic potential has been studied. The change in the ξ-potential (for anion and cation SAT) and particle size (1.5–2 times) was specified for SAT. The electroflotation efficiency of Cu(OH)₂, Cu₃PO₄, and CuS under the optimum conditions is 98.5 and 90%, correspondingly.     

Depolarization of broadband radiation in optical fibers with the twisted structure of birefringence

The depolarization of broadband linearly polarized radiation that propagates in optical fibers with the twisted structure of birefringence is investigated. The basic relationships for calculating the degree of radiation polarization at the fiber output at arbitrary fiber lengths and arbitrary azimuths of the input linear polarization are obtained. The depolarization length (on the order of several meters) at which the degree of polarization decreases from unity to a certain residual level is found. It is shown that the depolarization length depends on the width of the spectrum of a radiation source, the magnitude of the fiber’s built-in linear birefringence, and the twist pitch. For long fibers (of a length exceeding 50 m), the residual degree of polarization depends on the azimuth of the input linear polarization.     

Nanomaterials based on CdS nanoparticles in polyethylene matrix

The synthesis of CdS nanoparticles stabilized in the bulk of a polyethylene matrix is described. The size of synthesized nanoparticles is determined by means of transmission electron microscopy. The composition of nanoparticles is defined by X-ray phase analysis. It is shown that the variation of the process-dependent parameters during synthesis of nanoparticles in a polymer + oil solution melt results in the formation of CdS nanoparticles with average sizes of 4.9, 5.4, and 6.2 nm with a reasonably narrow size distribution and well-formed structure. The optical properties of synthesized nanomaterials are investigated. The investigation of Raman scattering reveals softening of the LO-phonon mode with decreasing CdS nanoparticle size. A broad high-energy band of photoluminescence connected with the exciton annihilation in conditions of size quantization is detected.     

Formation of residual stresses in coatings during high-energy treatment: A survey

The appearance of residual stresses in metals is one of the effects accompanying the action of high-energy treatment. Under both electrospark and laser treatments, temperature is a prevailing factor affecting the formation of residual stresses. High rates of heating and cooling of a metal in the melting zone result in the appearance of thermal stresses determined by the difference between the coefficients of thermal expansion of the metal. A combined electrospark and laser treatment creates a stressed state in the surface layer with better characteristics than each treatment does separately. The value, sign, and distribution of the residual stresses substantially influence the service properties of machine parts. Frantsevich Institute of Problems of Materials Science, Ukrainian Academy of Sciences, Kiev. Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 35, No. 6, pp. 72–78, November–December, 1999.     

Fiber-optic gyroscope with suppression of excess noise from the radiation source

A new optical system is proposed and investigated experimentally for a Sagnac fiber interferometer in which the excess noise of the wide-band radiation source is suppressed. A tenfold improvement in the sensitivity of a fiber-optic gyroscope with an erbium/ytterbium fiber superfluorescent light source was achieved experimentally. It is shown that the identity of the polarization characteristics of the interferometer channels plays an important role. Pis’ma Zh. Tekh. Fiz. 24, 30–35 (September 26, 1998)