Synthesis of 2-Substituted Benzimidazoles, Benzoxazoles, and Benzothiazoles from Arylsulfonyl(thio)propionitriles

The reaction of nitriles and of methyl imino ester hydrochlorides of arylsulfonyl(thio)propionic acids with o-phenylenediamine, o-aminophenol, and o-aminothiophenol has been studied. A series of new 2-substituted benzazoles has been synthesized containing arylsulfonyl(thio)propionic acid fragments.     

Reduction of the sonic boom level by heating the flow in front of the body

A numerical study of the possibility of reducing the sonic boom level in the case of local heat release to a supersonic gas flow at Mach number equal to 2 ahead of a body is described. The computations are performed for a spherical heat supply zone located on the flight trajectory ahead of the tip of an axisymmetric thin body. For the numerical study the combined method of “phantom bodies” is used. Different magnitudes of heat supply to the incoming flow are tested. These calculations are performed with allowance for interaction of shock waves emanating from the heated gas region and from the body in the far field. The computational results show that the local heat supply to a supersonic gas flow ahead of a body can reduce the sonic boom level by more than 20 %. The reduction of the sonic boom level is ensured by changing the free-stream parameters ahead of the body and by preventing the coalescence of shock waves from the heat supply zone and from the body in the far field.     

Ionic Liquids in Electrophoretic Separation and Preconcentration Processes

Journal of Analytical Chemistry - Ionic liquids (ILs) are widely used in separation methods such as chromatography and capillary electrophoresis due to their unique properties. This review...     

Investigation of mechanical properties of anodized aluminum using dilatometric measurements

Mechanical properties of anodized aluminum were studied using the results of dilatometric measurements of thermal expansion of anodized Al (the symmetric structure Al(2)O(3)-Al-Al(2)O(3)). The 100-microm-thick Al(2)O(3 )oxide layer was formed in 4% aqueous solution of oxalic acid in the galvanostatic regime at a current density of 20 mA cm(-2). Measurements of thermal expansion of anodized Al (Al and Mg alloy of 2.7-3.2%, and 0.3-0.6% Mn, and 0.5-0.8% Si) with the thickness of initial Al from 0.6 to 3.7 mm and ceramic from Al(2)O(3) in the temperature range of 20-500 degrees C were conducted using an automatic quartz dilatometer. Intrinsic stress in the Al layer, the values of the modulus of elasticity, and the porosity of Al oxide formed on Al of different thickness are calculated.     

A method of impedance measurements for study of curing of ED-20 epoxy resin

The method of impedance measurements was tested in a study of curing of ED-20 epoxy resin with 1,2,3,6-tetrahydro-3-methylphthalic anhydride (CAS 5333-84-6) in a thin layer between capacitor plates. A new equivalent electric circuit was suggested to describe the dielectric properties of the resin without using empirical equations.     

Effect of High Temperature Thermomechanical Treatment on the Tendency of Low-Activation 12% Cr Ferritic-Martensitic Steel EK-181 to Low-Temperature Embrittlement

Russian Physics Journal - The effect of high-temperature thermomechanical treatment (HTMT) with deformation in the austenitic region on the regularities of low-temperature embrittlement of...     

Energy of local uniaxial distortions in the crystal lattices of 5d metals

A simple model is proposed for estimation of the internal-energy change that takes place in paramagnetic transition metals in real and virtual high-symmetry crystalline modifications under uniaxial distortions of the lattice. This change is analyzed as a function of electron concentration against the background of energy competition between the phases considered. V. D. Kuznetsov Siberian Physicotechnical Institute, Tomsk State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 50–53, June, 1998.