Modification of zinc sulfide phosphors by irradiation with gamma-ray photons and electrons

The effect of γ-ray photons and electron beams on electroluminescence of the ZnS:(Cu, Br) and ZnS:(Cu, Al, Br) phosphors is studied. Irradiation of both samples with γ-ray photons and of the ZnS(Cu, Br) sample with electrons makes it possible to increase the emission intensity by 20–35% at the optimal radiation dose of 5–10 Mrad. In this case, the relative intensity of the green-emission band increases in the electroluminescence spectra of all samples, presumably due to dissociation of the Cu_I-Cu_Zn and Br_Zn-V _Zn donor-acceptor pairs. Thus, irradiation makes it possible to control the intensity and spectrum of phosphors’ emission, which can be used for nonchemical lithography of luminescent layers.     

Multisalt-carbon chemical cooler for space applications

Conclusions  The conclusions are summarized as follows:

Making blast-furnace smelting more efficient through the injection of heated natural gas

Subjecting natural gas to multi-stage heating by passing it through the cooled cavities of certain tuyere elements instead of coolant water is technically simple to accomplish and makes it possible to heat the gas to 300°C or more, the exact temperature depending on the amount of gas used. The cost of instituting this technology is an order of magnitude lower than the savings realized by injecting heated natural gas into blast furnaces. The injection of heated natural gas into a blast furnace introduces additional heat into the furnace and makes it possible to use more natural gas in the smelting process without reducing the theoretical combustion temperature. It also increases the value of the coefficient that characterizes the replacement of coke by natural gas, since the gas undergoes more complete combustion in this case. Finally, the injection of heated natural gas results in a more uniform distribution of hydrogen across the furnace and allows fuller use of this element in the smelting operation.     

Imbalance detection and classification system based on wavelet analysis and artificial neural networks

We present a robust algorithm for sequential imbalance detection (detecting a change of properties) for random processes with a wavelet packet transform. Based on this detector and artificial neural networks, we develop a classification system for different types of imbalance. We compare the resulting system with Shewhart control charts. The resulting system can be successfully used in selective control and under other conditions of imbalance detection and classification related to insufficient information about the signal before and after the change.     

Dispersion of optical and acoustic phonons in diamond and germanium crystals

The dispersion laws of the optical and acoustic branches in diamond-like crystals have been derived using idealized models of crystal lattices. Two types of analytical expressions have been proposed, whose parameters can be derived from inelastic neutron scattering experiments and the properties of acoustic waves. The calculation results are in satisfactory agreement with experimental data for the crystallographic directions [100], [110], and [111]. The group velocities of optical and acoustic phonons have been determined, and expressions for the effective mass of optical phonons have been derived.     

Synthesis of vanadium dioxide films by a modified sol-gel process

Vanadium dioxide films have been grown on silicon substrates and on SiO₂ layers on silicon by a modified sol-gel process using methyl cellosolve as a solvent. We have failed to obtain vanadium dioxide layers on Pt/TiO _x /SiO₂/Si substrates. For all of the substrates studied, we have examined the effect of synthesis conditions (initial solution concentration, deposition procedure, and oxidation and reduction anneals) on the phase composition, thickness, and surface morphology of the films.     

Acoustic emission in hafnium under tensile deformation

The paper addresses the dependence of acoustic emission produced in rolled hafnium GFé-1 under tensile deformation on the material’s structural state. A correlation has been established between the material structure, the level of mechanical properties and the values of acoustic parameters. Acoustic emission in non-recrystallized hafnium under tensile deformation is recorded only at the stages that precede fracture. Upon recrystallization annealing at temperatures of 1123 and 1373 K acoustic emission occurs at all the stages of tensile deformation. The highest level of acoustic emission activity in hafnium is observed during the transition from elastic to elastic-plastic strain.     

Deep grinding of incomplete-cycle surfaces, with periodic straightening of the wheel

The formation of the force components in opposed and unidirectional deep grinding is considered, taking account of wear of the wheel. The influence of the direction of table supply on the grinding force and stability of the tool edges is shown. In considering the results, the impact at initial contact of the abrasive grains with the blank is taken into account.     

Properties of vapor-deposited borophosphorosilicate glass layers employed in technology of silicon integrated circuits

The data of investigations on the physicochemical and electrophysical properties of borophosphosilicate glass layers deposited from mixtures of tetraethoxysilane and esters of boric and phosphoric acids in an oxygen-ozone medium (temperature, 400–440°C; atmospheric and subatmospheric pressures) have been generalized. The empirical relationships are obtained for determining the boundaries of the optimum dopant concentration region when the glass is used as a reflow interlayer dielectric in integrated circuit technology. The assumption is made that the structure of borophosphosilicate glass layers is formed by a porous network involving dopant clusters.