Coagulation in lipid- and protein-containing systems

The behavior of real disperse systems with organic impurities was examined under conditions of destabilization by inorganic coagulants. A number of physicochemical methods of analysis and a simulation method were used to identify the character and type of the complexes formed and to calculate their stability constants.     

Solubility of ammonium palmitate in supercritical carbon dioxide

The solubility of ammonium palmitate in supercritical carbon dioxide is studied in the dynamic regime at 308.15–333.15 K and 10.0–35.0 MPa. Experimental data are described in the framework of the Peng–Robinson equation of state.     

Preparing biodiesel fuel in supercritical fluid conditions with heterogeneous catalysts

Noncatalytic and catalytic transesterification of rape oil were studied in an ethanol medium under supercritical fluid conditions, ultrasonic effect, temperature range from 623 to 653 K, 30 MPa, and with 12: 1 and 18: 1 alcohol to oil mole ratios. An effect of heterogeneous catalysts on the reaction rate was defined. Correlation dependence between the amount of fatty acid ethyl esters in biodiesel fuel and kinematical viscosity of the reaction product was determined.     

Effect of treatment in supercritical CO<Subscript>2</Subscript> on the composition and structure of tealeaf and cellulose

The influence of the pretreatment procedures with supercritical CO₂ (SC-CO₂) on the elemental composition of tealeaf is studied. Fourier-transform infrared absorption spectroscopy is used to examine the effect of SC-CO₂ on the structure of Chinese green tea and cellulose.     

Intermolecular interactions in metal-containing polymers based on 2,4-toluylene diisocyanate and open-chain analogs of crown ethers

The interaction of 2,4-toluylene diisocyanate with open-chain analogs of crown ethers containing potassium alcoholate groups is studied, and the mechanism of stabilization of the formed O-polyisocyanate end units via intermolecular interactions is proposed. The electron delocalization in intermolecular cyclic structures may be responsible for electron-transfer processes in the polymers under study.     

Self-similar growth of a gas hydrate layer separating gas and liquid

The plane one-dimensional Stefan-type problem of the growth of a layer of solid phase separating a gas and a liquid is studied. A self-similar solution and the necessary conditions of its existence are obtained. A number of estimates of the characteristic rates of growth of the layer and the concentration and temperature gradients in the phases are presented, and the results of calculating the growth of the hydrate layer in a water-methane system at a pressure of 10 MPa and a temperature of 283°K are analyzed.Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No.5, pp. 78–85, September–October, 1992.