On the stability of the system of linear domains in planar nematics under oscillatory compression

Stability under periodic compression strain is studied for the system of linear domains formed in the planar layer of a nematic liquid crystal due to periodic shear deformation. The critical amplitude of this oscillatory compression is found, at which this system becomes unstable and undergoes a transformation that is manifested in the formation of spatially modulated structures with various conformations.     

Oxidation of cyclohexene with Ce (IV) salts

Conclusions Together with the main products, namely cyclohexen-2-ol and cyclohexen-2-one, the oxidation of cyclo-hexene with cerium ammonium nitrate or cerium ammonium sulfate gives cyclohexanol and cyclohexanone, which are probably formed by the cation-radical mechanism.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1664–1666, July, 1977.     

Nonlinear effects of laser radiation and physical model of laser agglomeration process

Nonlinear effects of pulsed and continuous laser radiation on mineral samples from technogenic placers in the Amur river region, containing submicron gold which cannot be extracted by modern gravity separation methods, were studied. The formation of self-organized gold structures on the surface of silicate matrix was detected, and general relations for the agglomeration and concentration of “nonrecoverable” gold species were found. The agglomeration process was simulated by a nonlinear heat conduction equation for onedimensional case including laser radiation parameters.     

Mechanism for the formation of bubble domains

Abstract

The mechanism for the formation and stabilization of acoustic bubble domains is investigated experimentally within the framework of the Akahane and Tako model which is based on the assumption of the formation of a system of defects in the layer of a cholestric liquid crystal, these defects pin the bubble domains. The theory takes no account of the interaction between bubble domains, this being valid in the case of a low density of domain packing. The correlation between the experimental results and theory is quite satisfactory, especially in the region of d/P ₀ < 1.5 where the bubble domain packing density is very low (where d is the thickness of the cholestric layer and P ₀ is the pitch of the helix).     

Liposoluble pigments of edible roots of Beta vulgaris

The qualitative and quantitative comopsition of the chlorophylls and carotenoids of the edible roots of table beets of the varieties Bordeaux and Nosovskaya Ploskaya have been determined by chromatographic and spectral methods.M. V. Lomonosov Odessa Technological Institute of the Food Industry. A. V. Bogatskii Physicotechnical Institute, Ukrainian SSR Academy of Sciences, Odessa. Konservpromkompleks VINNPKI, Odessa. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 710–712, September–October, 1988.     

Oxidative cleavage of 1-alkylcyclopentanols by lead tetraacetate-metal chloride system

Conclusions Oxoalkyl radicals are generated when the lead tetraacetate-alkali or alkaline earth metal chloride system is reacted with 1-alkylcyclopentanols, which are oxidized to chloroketones.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2383–2385, October, 1979.     

Solid-phase oxoalkylation of pyridines and quinolines with 1-methylcycloalkanols under the action of lead tetraacetate

A new procedure was developed for the introduction of the oxoalkyl fragment into N-heteroaromatic compounds of the pyridine and quinoline series. The procedure is based on the solid-phase reactions of lead tetraacetate with aromatic N-heterocycles and tertiary cycloalkanols.