Waste cooking oil (WCO) was used as a potential feedstock for biodiesel production. High levels of free fatty acids (9.85% w/w) in WCO made it an undesirable substrate for direct transesterification reaction. To solve this issue, a two-step process was implemented in this research. Firstly, esterification reaction was performed in presence of sulfuric acid as a common acid catalyst to reduce th...

Experimental data for the unimolecular decomposition of CS2 from the literature are analyzed by unimolecular rate theory with the goal of obtaining rate constants for the reverse reaction S + CS (+M) → CS2 (+M) over wide temperature and pressure ranges. The results constitute an important input for the kinetic modeling of CS2 oxidation. CS2 dissociation proceeds as a spin-forbidden process whos...

Temperature-dependent free radical reactions were investigated using nitroxyl radicals as redox probes. Reactions of two types of nitroxyl radicals, TEMPOL (4-hydroxyl-2,2,6,6-tetramethylpiperidine-N-oxyl) and carbamoyl-PROXYL (3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-N-oxyl), were tested in this paper. Heating a solution containing a nitroxyl radical and a reduced form of glutathione (GSH) c...

Does it matter in what order the four irrigations are conducted in the caloric test? It has been suggested that warm water (44 degrees C) elicits stronger reactions than does cold water (30 degrees C), which might be explained simply by slight differences in water temperatures. However, if it can be shown that starting with cold water diminishes the difference between the warm and cold irrigati...

in this study, the conditions for producing invert syrup were optimized and factors such as type of acid citric, hydrochloridric and tartaric (each at two levels), reaction time (1 and 1.5 h) and temperature (70 and 80°c) were studied. the properties of invert syrups which produced by different methods were compared with each other and a standard and optimized method, for inversion reaction, wa...

A thermostatted reaction cuvet, operating under computerized or manual temperature control in the ultraviolet or visible region, is described and evaluated. The cell was designed for use with the automated chemistry system described earlier [Clin. Chem. 19, 1114 (1973)], but can readily be adapted for other applications. The entire 3-ml cuvet assembly warms from ambient temperature to 37 degree...

the kinetics and mechanism of the reaction between benzaldehyde 1, malononitrile 2 and dimedone 3 in a mixture of ethanol and water as solvents in the presence of fructose as a biodegradable catalyst has been studied by the spectroscopic method (uv-vis spectrophotometry method). the influence of various parameters (temperature, solvent and concentration) was studied on the reaction by means of ...

F(1)-ATPase is a rotary molecular motor that makes 120 degrees stepping rotations, with each step being driven by a single-ATP hydrolysis. In this study, a new reaction intermediate of F(1)-ATPase was discovered at a temperature below 4 degrees C, which makes a pause at the same angle in its rotation as when ATP binds. The rate constant of the intermediate reaction was strongly dependent on tem...

Using the thermodynamics of DNA melting, a technique is proposed to choose a reaction temperature for the DNA computation that minimizes the potential for mishybridizations. Adleman[Adleman, 1994] showed the computational potential of the hybridization reaction and other molecular biology protocols. A basic framework for a computation based on oligonucleotide template matching reactions, or hyb...