Dependence of the Surface Morphology and Structure of CuIn0.95Ga0.05Se2 Films on the Selenization Temperature

Semiconductors - Depending on the choice of the technology for producing CuInxGa1 – xSe2 films, a spread in the electrophysical and photoelectric parameters of...     

Unsteady-state combustion of a granulated solid propellant in a cylindrical channel

The unsteady-state combustion of a granulated solid propellant (GSP) in a cylindrical confined vessel with a uniformly perforated lateral surface is considered. The vessel is placed in a simulation chamber. The GSP specimens are heated by incandescent particles supplied by a hot gas flow through the left perforated face of the vessel. The right face of the vessel is either blank or perforated. The one-dimensional gasdynamic problem is solved by the method of large particles, with the solution of the Euler problem being modified. The one-dimensional thermal problem is solved for individual granules of the propellant in each gasdynamic unit. The behavior of the unsteady-state combustion of the GST affected by variations in the initial temperature and initial burning web of propellant granules as well as the mass and the number of granules in the tested volume has been analyzed numerically. The results of the analysis are reported.Institute of Applied Mathematics, Ural Branch, Russian Academy of Sciences, Izhevsk 426001. Translated from Fizika Goreniya i Vzryva, Vol. 30, No. 6, pp. 43–51, November–December, 1994.     

Continuous Selective Heating of the Solid Phase of a Dispersion

A new technique is suggested for the continuous and selective heating of the solid phase in a flowing dispersion. This technique is implemented in a heater–valve-pulsed apparatus unit. Mathematical models are developed for the cocurrent and countercurrent designs of the heater. Analytical solutions are obtained for the model equations, and parameters governing the continuous selective heating of the solid phase are determined. A design algorithm is suggested for the unit.     

Synthesis and properties of calcium hydroxyapatite/silk fibroin organomineral composites

The coprecipitation of calcium hydroxyapatite (HA) (Ca₁₀(PO₄)₆(OH)₃) and silk fibroin (SF) from an aqueous solution in the Ca(NO₃)₂–(NH₄)₂HPO₄–NH₃–H₂O–SF system has been used to synthesize HA/SF organomineral composites based on nanocrystalline HA, containing 2, 5, and 10 wt % SF. The synthesis products were characterized by X-ray diffraction, thermogravimetric analysis, infrared spectroscopy, scanning electron microscopy, and electron spectroscopy for chemical analysis.     

Monocyclic Quinone Structure-Activity Patterns: Synthesis of Catalytic Inhibitors of Topoisomerase II with Potent Antiproliferative Activity

The monocyclic 1,4-benzoquinone, HU-331, the direct oxidation product of cannabidiol, inhibits the catalytic activity of topoisomerase II but without inducing DNA strand breaks or generating free radicals, and unlike many fused-ring quinones exhibits minimal cardiotoxicity. Thus, monocyclic quinones have potential as anticancer agents, and investigation of the structural origins of their biological activity is warranted. New syntheses of cannabidiol and (±)-HU-331 are here reported. Integrated synthetic protocols afforded a wide range of polysubstituted resorcinol derivatives; many of the corresponding novel 2-hydroxy-1,4-benzoquinone derivatives are potent inhibitors of the catalytic activity of topoisomerase II, some more so than HU-331, whose monoterpene unit replaced by a 3-cycloalkyl unit conferred increased antiproliferative properties in cell lines with IC₅₀ values extending below 1 mM, and greater stability in solution than HU-331. The principal pharmacophore of quinones related to HU-331 was identified. Selected monocyclic quinones show potential for the development of new anticancer agents.     

Development and application of a new lead-free steel for making distributor parts of Otto engines

Metal Science and Heat Treatment - Results of the development and introduction into commercial production of lead-free fine-machining steel to replace the lead-bearing steel AS45G2 for making...     

The fill factor of load current-voltage performance of solar cells and its role for determining their temperature properties

The experimental and calculated relationships between the no-load voltage, the fill factor of the solar cell current-voltage performance, and the temperature are compared. A new expression that describes the relationship between the fill factor of the solar cell current-voltage performance and the temperature, which can be used for describing the parameters of a solar cell based on different semiconductors, is created.     

Domestic Hydrotreating Units. Status and Modernization Methods

Data on use of domestic hydrotreating units are generalized. Ways of enhancing operation of the units to improve their technical and economic indexes are indicated. The results of operation of the L-24-6 unit at Angarsk Petrochemical Co. on AGKD-205A catalyst for manufacture of diesel fuel with a sulfur content of less than 0.05% are reported.__________Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 3, pp. 15 – 17, May – June, 2005.