Kinetic properties of soluble and immobilizedCandida rugosa lipase

Immobilized lipase (triacylglycerol ester hydrolase, EC 3.1.1.3) fromCandida rugosa has been immobilized on commercially available microporous polypropylene and used for the batch hydrolysis of different animal fats. The effect of the reaction products at concentrations similar to those obtained at 90% hydrolysis, both on soluble and immobilized lipase, was studied. Glycerol showed low inhibitory effect but oleic acid caused 50% inhibition. A mixture of free fatty acids present in the complete hydrolysis of beef tallow inhibited lipase activity more than 70%. The stability of the enzyme (both soluble and immobilized) was highest in the presence of 20% isooctane. The apparent Michaelis constant for each substrate for the soluble enzyme did not change on immobilization.     

Anomalies in transport properties of EuO under hydrostatic pressure due to bound magnetic polaron

Resistivity vs hydrostatic pressure has been measured at room temperature for several EuO samples which span a large range of resistivity. We show that the pressure coefficient of activation energy of resistivity β = KT (d log ?/d p) varies continuously with room temperature resistivity. The samples which present an insulator-metal Transition have unusual values of β. We relate these values to the presence of bound magnetic polaron or molecular bound magnetic polaron.     

Study of structural and electronic transport properties of Ce-doped LaMnO3

The structural and electronic transport properties of La_1−x Ce _x MnO₃ (x=0.0–1.0) have been studied. All the samples exhibit orthorhombic crystal symmetry and the unit cell volume decreases with Ce doping. They also make a metal-insulator transition (MIT) and transition temperature increases with increase in Ce concentration up to 50% doping. The system La_0.5Ce_0.5MnO₃ also exhibits MIT instead of charge-ordered state as observed in the hole doped systems of the same composition.     

Spectral photoconductivity in high manganese concentration Cd0.27Mn0.73Te

Photoconductivity results are reported for samples of Cd_0.27Mn_0.73Te. They are compared to the absorption ones, in the range 1.8–3 eV. The frequency response study allows us to present a model consistent with both phenomena: the minimum observed in the photoconductivity spectrum is attributed to a competition between the intrinsic absorption and the intra- manganese transitions. In addition the transitions between 6_A1?4_T1 and 6_A2?4_T2 could be separated; they are unresolved in the absorption spectrum giving a wide bump.