Binding of aroma compounds with legumin. III. Thermodynamics of competitive binding of aroma compounds with 11S globulin depending on the structure of aroma compounds

This paper considers the prominent features in competitive binding of aroma esters from their mixtures to 11S globulin of broad beans (legumin) in aqueous medium at pH 7.2 and ionic strength of 0.05 mol dm⁻³. Series of alkyl acetates (C₄–C₈) and methyl esters of carbonic acids (C₅–C₉), differing in the length of hydrocarbon chain, have been under our studying. To accomplish the ends of the study, a combination of ultrafiltration and gas–liquid chromatography (GC) has been used. An increase in the length of hydrocarbon chain of the aroma esters brought about greater binding affinity for the protein, the occurrence of some structural restrictions in the interior of the protein molecule, preventing binding, and the change in the binding mechanism of the aroma compounds at the specific critical length of hydrocarbon chain. Differential scanning microcalorimetry data suggested that the revealed changes in the binding mechanism of the studied aroma compounds were attributable to the conformational modification of the protein globule as a result of binding with the aroma compounds. A distinguishing feature in binding of methyl esters of carbonic acids with legumin was their greater binding affinity for the protein as compared with alkyl acetates. The mutual effect of aroma compounds on binding from their equimolar mixtures to the protein made itself evident, firstly, as a drastic increase in the binding extent of aroma esters, having rather long hydrocarbon chain and, secondly, as a dramatic change in the binding mechanism of the aroma esters with relatively short hydrocarbon chain.     

Experimental study of phase equilibria in the PbO-ZnO-“Fe2O3”-(CaO + SiO2) system in air for the lead and zinc blast furnace sinters (CaO/SiO2 weight ratio of 0.933 and PbO/(CaO + SiO2) ratios of 2.0 and 3.2)

Experimental studies on phase equilibria and liquidus in the multicomponent system PbO-ZnO-CaO-SiO₂-FeO-Fe₂O₃ in air have been conducted over the temperature range between 1323 K (1050 °C) and 1623 K (1350 °C) to characterize the phase relations of the complex slag systems encountered in lead and zinc blast furnace sinters. The liquidus in two pseudoternary sections ZnO-“Fe₂O₃”-(PbO + CaO + SiO₂) with the CaO/SiO₂ weight ratio of 0.933 and PbO/(CaO + SiO₂) weight ratios of 2.0 and 3.2 have been constructed.     

Precursor synthesis and properties of iron and lithium co-doped cadmium oxide

Journal of Electroceramics - Lithium and iron co-doped cadmium oxide Cd0.9(Li1-xFex)0.1O (x?=?0.1, 0.3, 0.5, 0.7) with NaCl structure has been synthesized using formate of the...     

Note: Utilizing Pb(Zr(0.95)Ti(0.05))O(3) ferroelectric ceramics to scale down autonomous explosive-driven shock-wave ferroelectric generators

Further miniaturization of recently designed autonomous ferroelectric generators (FEGs) [S. I. Shkuratov, J. Baird, and E. F. Talantsev, Rev. Sci. Instrum. 82, 086107 (2011)], which are based on the effect of explosive-shock-wave depolarization of poled ferroelectrics is achieved. The key miniaturization factor was the utilization of high-energy density Pb(Zr(0.95)Ti(0.05))O(3) (PZT 95∕5) ferroelectric ceramics as energy-carrying elements of FEGs instead of the previously used Pb(Zr(0.52)Ti(0.48))O(3) (PZT 52∕48). A series of experiments demonstrated that FEGs based on smaller PZT 95∕5 ferroelectric elements are capable of producing the same output voltage as those based on PZT 52∕48 elements twice as large. It follows from the experimental results that the FEG output voltage is directly proportional to the thickness of PZT 95∕5 samples. A comparison of the operation of FEGs based on PZT 95∕5 and on PZT 52∕48 ferroelectrics is presented.     

Manufacture of polymer composite materials using copolymeric latexes of different nature

The use of low-emulsifier latex obtained by radiation emulsion polymerization allows increasing the physicomechanical properties of finished fabrics at low binder weight gain. It was shown that the wave effect on latex composites of different composition increases the physicomechanical properties of latex films and nonwovens and improves their functional properties. __________ Translated from Khimicheskie Volokna, No. 3, pp. 12–14, May–June, 2007.     

Selected Phase Equilibria Studies in the Al2O3–CaO–SiO2 System

The Al₂O₃–CaO–SiO₂ system provides the basis for describing many important chemical processes. Although the system has previously been extensively studied, recent advances in experimental technique have provided the opportunity to obtain accurate liquidus measurements in the low‐silica region at fixed temperatures. The experimental procedures involve equilibration of high‐purity oxide powder mixtures at selected temperatures, rapid quenching, and accurate measurement of phase compositions using electron probe X‐ray microanalysis. The liquidus isotherms have been determined at selected temperatures between 1503 and 1873 K in the anorthite, gehlenite, pseudowollastonite, corundum, CaAl₁₂O₁₉, CaAl₂O₆, lime, Ca₃SiO₃, and Ca₂SiO₄ primary phase fields. The results are compared with currently available thermodynamic model predictions of the phase chemistry.     

Experimental phase equilibria studies of the PbO–SiO2 system

Phase equilibria of the PbO–SiO₂ system have been established for a wide range of compositions: (i) liquid in equilibrium with silica polymorphs (quartz, tridymite, and cristobalite) between 740°C and 1580°C, at 60‐90 mol% SiO₂; (ii) with lead silicates (PbSiO₃, Pb₂SiO₄, and Pb₁₁Si₃O₁₇) and lead oxide (PbO) between 700°C and 810°C. A high‐temperature equilibration/quenching/electron probe X‐ray microanalysis (EPMA) technique has been used to accurately determine the compositions of the phases in equilibrium in the system. Significantly, no liquid immiscibility has been found in the high‐silica range, and the liquidus in this high‐silica region has been accurately measured. The phase equilibria information in the PbO–SiO₂ system is of practical importance for the improvement of the existing thermodynamic database of lead‐containing slag systems (Pb–Zn–Fe–Cu–Si–Ca–Al–Mg–O).