Comparison of the results of interference and numerical determinations of stream density in a separation zone

Density fields in the separation zone are determined from interferograms of supersonic turbulent flow over a body. A comparison is made with the results of numerical calculations by a combined scheme.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 49, No. 5, pp. 769–773, November, 1985.     

The solubility and dissolution rate of alumina in acidic cryolite aluminous melts

The dissolution rate of alumina (v) is evaluated in cryolite alumina melts with a cryolite ratio (CR) lower than 2.1 to determine the possibility of further increasing the AlF₃ concentration in industrial electrolytes in order to increase the current efficiency of modern electrolyzers. The value of v was determined by the electrochemical method based on the measurement of equilibrium electromotive force of a concentration galvanic cell after loading the portion of alumina into the melt. It is established that the decrease in CR < 2.1 leads to the essential reduction of solubility of alumina and its dissolution rate. According to the dependence of v on the alumina content in the melt, it is shown that the processes of mass and heat transfers are the limiting stages.     

Electrical conductivity of NaF-AlF<Subscript>3</Subscript>-CaF<Subscript>2</Subscript>-Al<Subscript>2</Subscript>O<Subscript>3</Subscript> melts

The electrical conductivity of NaF-AlF₃-Al₂O₃ melts with a CaF₂ concentration of 5 wt % is measured at a continuously varying cell constant when the molar cryolitic ratio CR = [NaF]/[AlF₃] changes from 1.2 to 2.0 [1, 2]. The experimental data are used to obtain a regression equation to describe the dependence of the electrical conductivity of the melts under study on CR, the alumina content, and temperature {χ] = f(CR, [Al₂O₃], T)}.     

Some features of the ion-beam mixing during simultaneous ion implantation and metal deposition

Experimental results on the ion implantation of Ta and Cu ions into an Al substrate, accompanied by the deposition of these ions in the form of a surface coating are reported. The coatings composed of the implant elements exhibit a complicated structure and lead to an increase in the microhardness, adhesion properties, and corrosion resistance of the substrate. An analysis of data on the energy distribution of secondary ions shows that the surface layer of ion-implanted substrates contains intermetallic phases.     

Computational and experimental methods in the systems of current diagnostics of thermal stresses in elements of machines and structures

Application of the inverse-problem methods of experimental mechanics for diagnosing thermal states of elements and structures is considered. An inverse problem of nonstationary thermal conductivity and an iteration method for its solution on the basis of an alternating procedure are studied.     

Properties of clays for manufacturing sanitary ware

Clays from different producers are investigated. The chemical and mineral compositions and the granularity of the clays are analyzed. Their basic differences and the effect on the properties of the finished pastes are shown. The clay properties which are necessary to optimize the composition of ceramic pastes are determined. The rheological characteristics and how they affect the control of the technological process are examined. The main advantages and disadvantages of different clays—traditional domestic clays and some new ones—are established. __________ Translated from Steklo i Keramika, No. 3, pp. 10–13, March, 2007.