the photocatalytic degradation of a common analgesic (acetaminophen) with titanium dioxide irradiated with low energy ultraviolet light (365 nm) was studied in order to determine the effect of several parameters such as catalyst’s weight, photochemical effect, and initial concentration. the results indicate that acetaminophen is degraded in the order of 4% by the photochemical effect. the pres...

The extent of cooperativity among the polypeptide chain components in the overall reaction catalyzed by the pyruvate dehydrogenase multienzyme complex from Escherichia coli has been studied. Selective inactivation of the pyruvate dehydrogenase component with thiamin thiazolone pyrophosphate demonstrates that no cooperativity between this component and the overall catalytic reaction occurs: the ...

1. A method was devised for preparing pig heart pyruvate dehydrogenase free of thiamin pyrophosphate (TPP), permitting studies of the binding of [35S]TPP to pyruvate dehydrogenase and pyruvate dehydrogenase phosphate. The Kd of TPP for pyruvate dehydrogenase was in the range 6.2-8.2 muM, whereas that for pyruvate dehydrogenase phosphate was approximately 15 muM; both forms of the complex contai...

a superhydrophobic aluminum surface was fabricated through an enhanced low-cost approach and the effects of several relevant factors on static contact angle and sliding angle were investigated. first, the operating parameters including the etching time as well as the reaction time and temperature were varied. next, the so-called chemical factors including three different fatty acids and five di...

The information has always been a valuable patrimony for the information systems that every company tries to capitalize as much as possible. With the web, the amount of information is increased and several problems arise for instance for the safety of the exchanged data but also to the semantic heterogeneity: the same information is very often represented in different ways in different informat...

Photoionization methods have been used to study the reactions of the molecular ion in vinyl fluoride to yield the ionic products C3H 3F{, C3H 4F+, and C3Ht. Quantitative measurements are reported of the effect of the vibrational state of the reactant ion on the product distribution and overall reaction cross section. Reaction cross sections for all three channels decrease with reactant internal...

Reaction enthalpies and reaction volumes of proton-transfer reactions in aqueous solutions of 3-hydroxypyridine have been estimated by measuring UV-visible absorption spectra at different temperatures, pressures, and pH values. Using these results together with published thermodynamic and kinetic data, we have simulated the relaxation spectrum of the proton-transfer reactions of 3-hydroxypyridi...

Cyclic voltammogram and differential pulse polarograph of octaethyl porphyrin iron(III) chloride in dichloromethane was investigated in the presence of pyridine, imidazole and collidine. Values of E1/2 for FeIII/FeII redox reaction were monitored as a function of axial group concentration, and on the basis of these data, an overall oxidation-reduction and ligand addition scheme was formulated. ...

The entropy production in a non-equilibrium state based on the reversible Oregonator model of the BelousovZhabotinskii (BZ) reaction system has been studied. The reaction affinity and the reaction rate for the individual steps have been calculated by varying the concentrations of key variables in the system. The result shows a linear relationship between the reaction affinity and the reaction r...