Interaction of Oxide Melt with External-Trap Zirconium Dioxide Refractories

The results of an investigation of the interaction of zirconium dioxide refractories – ceramic and concrete with iron oxides – are presented. The investigations showed that starting at 1600 K in an argon atmosphere contact of a mixture of iron oxides with refractories gives rise to erosion of the latter. Under isothermal conditions (2270 K), ceramic with 16% porosity completely absorbs a melt with mass 1/7 of the ceramic mass. The concrete confines the same melt mass with a lower temperature 1870 K and, in the process, unlike the ceramic, it loses strength.The results obtained and the published data were used to analyze the operation of a refractory protective layer of an EPR trap.     

Underground Mining of Kimberlite Pipes under Alluvia

The scheme is proposed for underground mining of kimberlite pipe under alluvia 80-100 m in thickness. The main features of the technology are the refusal to carry out filling operations and use ore vibration discharge ensuring its simultaneous flow over the pipe cross-section.     

Passivation of the GaP(111) surface by treatment in selenium vapors

Results of examination of structural phase transitions on the GaP(111) surface after heat treatment in selenium vapors in a vacuum chamber with a quasi-closed volume are described. The electrophysical characteristics of Schottky-barrier diodes on GaP(111) are studied before and after treatment in selenium vapors by measuring the current-voltage characteristics and by deep-level transient spectroscopy. It is found that, after treatment in selenium vapors, the Schottky-barrier height becomes dependent on the work function of the metal in accordance with the Schottky-Mott rule for an ideal diode. It is shown that a decrease in the density of surface electronic states in GaP(111) results from the formation of a Ga₂Se₃(111)(√3 × √3)-R30° surface phase with ordered stoichiometric gallium vacancies.     

Innovative technologies for full utilization of ash generated at coal-fired thermal power stations for producing alumina and construction materials

The possibility of full 100% usage of ash from coal-fired thermal power stations for producing raw materials for the cement and alumina industries is considered, and it is shown that comprehensive processing of ash from coal-fired thermal power stations is required for this purpose.     

Increasing the resolution in images of two mutually coherent sources

It is shown that the use of the spatial phase shifting method for determining the distance between two mutually coherent point sources serves to improve resolution more than ten-fold. __________ Translated from Izmeritel’naya Tekhnika, No. 3, pp. 19–21, March, 2008.