Temperature distribution in a triangular laser rod

Variational methods are applied to give approximate solutions for the temperature distribution in a right equilateral triangular prism.     

Topological transformation of phase diagrams in KBr–оxyethylated surfactant–water pseudo-ternary systems

A scheme was developed to explain the transformation of phase diagrams for KBr–oxyethylated surfactant–water systems in response to varying temperature. This scheme was shown to correspond with the respective scheme for salt–binary solvent systems. The surfactant structure was shown to have an effect on the temperature ranges of existence of a liquid–liquid two-phase equilibrium field and the positions of critical points. The elucidated trends serve as the basis for selecting components and optimizing parameters of surfactant- involving extraction processes.     

Synthesis of (2S, 5S)-2,5-dimethoxyadipic acid

Conclusions (2S,5S)-Dimethoxyadipic acid was synthesized from the D-mannitol derivative.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2151–2153, September, 1974.     

Lytic enzymes of staphylococcal phages: Correlation between secondary structure and stability

Lytic enzymes of bacteriophages K, phi11, and phi80α can lyse (destroy) cells of antibiotic-resistant strains of Staphylococcus aureus, which makes these enzymes promising antimicrobial agents. The stability of recombinant lysins of phages K, phi11, and phi80α was investigated under the conditions of storage and functioning, and the correlation between the stability and the secondary structure of the enzymes was found. It has been shown that the lower the content of disordered structures in the enzyme molecules, the greater the stability (half-inactivation time) of the lysins. At the storage temperature, the beta-structural lysin of phage phi11 shows the highest stability, while the phage K lysin with an alpha-helical structure and the phi80α lysin with a disordered secondary structure are less stable.     

Effect of the salting-out agent anion nature on the phase separation of a potassium salt–potassium bis(alkyl polyoxyethylene)phosphate–water systems

The effect the salting-out agent anion nature has on the temperature and concentration intervals of the existence of the separation area is established by analyzing the phase diagrams of pseudoternary KCl (KBr, KI, KNO₃, K₂SO₄, K₄P₂O₇)–potassium bis(alkyl polyoxyethylene)phosphate (oxyphos B)–water systems. It is concluded that the anionic salting-out capability is reduced in the order P₂O₇^4-> SO₄^2-> Cl^? > Br^?> NO₇^4-> SO₃^-> I^?. The thermodynamic parameters of phase separation used to interpret the results are calculated. The observed pattern of a change in the salting-out ability of the investigated salts relative to aqueous solutions of the surfactants is in good agreement with the lyotropic (Hofmeister) series.     

Investigation of intermolecular interactions in solutions by means of millimeter-wave spectroscopy 4. Negative and positive hydration in aqueous solutions of urea

Measurements have been made of the absorption of EHF radiation ( 5 cm^–1) by aqueous solutions of urea at 20–70°C, over the entire interval of urea solubility. Excess absorption has been found in comparison with the additive magnitude, and this has been attributed to an increase in the fraction of water molecules in the solution with rotational degrees of freedom. A model has been proposed for the hydration of urea, based on the concept of inhomogeneity of the hydrate shell of urea: stabilization of the structure of water under the influence of carbonyl oxygen and H_cis atoms (positive hydration) and a simultaneous breakdown of the structure of water in the region of two H_trans atoms that have approached to a distance of 2.14 » (negative hydration).For Previous Communication, See [1].Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 314–320, February, 1990.     

Modulation of the adsorption properties at air-water interfaces of complexes of egg white ovalbumin with pectin by the dielectric constant

The possibility of modulating the mesoscopic properties of food colloidal systems by the dielectric constant is studied by determining the impact of small amounts of ethanol (10%) on the adsorption of egg white ovalbumin onto the air-water interface in the absence and presence of pectin. The adsorption kinetics was monitored using tensiometry. The addition of ethanol resulted in considerably slower adsorption of the protein onto the interface, and this effect was enhanced when the protein was in complex with the pectin. Time-resolved fluorescence measurements demonstrated that in the case of noncomplexed ovalbumin the addition of ethanol resulted in a more condensed protein surface layer where ovalbumin adopted a preferred orientation at the interface. In contrast, the effect of ethanol on the ovalbumin-pectin complex suggested a pronounced multipoint electrostatic interaction between protein and polyelectrolyte and the formation of a more rigid spatial arrangement within the complex, thereby leading to suppressed protein-protein interactions. From this work it is concluded that by the enhanced binding affinity between ovalbumin and pectin a strong effect on the adsorption properties of the protein can be accomplished. This work does therefore illustrate how solvent quality can be exploited effectively to enhance or suppress protein functional behavior in complex applications containing air-water interfaces.