The kinetic characteristics of soil urease have attracted great attention, but little information was available on its kinetic and thermodynamic behaviors as affected by urease inhibitors and temperature. With black soil (Pachic Udic Mollisol) in Heilongjiang Province of Northeast China as a test soil, an incubation test was conducted to investigate the effect of urease inhibitors (hydroquinone...

A previously developed kinetic model for two-component vapour and background gas (air) is applied to the analysis of droplet heating and evaporation in Diesel engine-like conditions. The model used in the analysis is based on the introduction of the kinetic region in the immediate vicinity of the droplets and the hydrodynamic region. The presence of two components in the vapour, finite thermal ...

The first ultraviolet sources in the universe are expected to have coupled the H i spin temperature to the gas kinetic temperature via scattering in the Lyα resonance (the “Wouthuysen-Field effect”). By establishing an H i spin temperature different from the temperature of the cosmic microwave background, the Wouthuysen-Field effect should allow observations of H i during the reionization epoch...

Laser wave mixing is presented as an effective technique for spatially resolved kinetic temperature measurements in an atmospheric-pressure radio-frequency inductively-coupled plasma. Measurements are performed in a 1 kW, 27 MHz RF plasma using a continuous-wave, tunable 811.5-nm diode laser to excite the 4sP2 4pD3 argon transition. Kinetic temperature measurements are made at five radial steps...

It is shown that the degree of regulatory kinetic behavior of rabbit muscle phosphofructokinase increases at a given pH and lower temperatures, as well as at a given temperature and lower pH values. It is also shown that the regulatory kinetic behavior which appears at lower pH values is inherent in the tetrameric (active) form of the enzyme. We conclude that a portion of the mechanism proposed...

The extracts of Piper sarmentosum, a medicinal plant, are being used to prepare phytopharmaceuticals while the information about chemical kinetics of constituents of the extract is unavailable to assign precise shelf life (t90) and find optimum storage conditions of the product for patient safety, and to avoid economic repercussions of launching an unstable product. The extract was exposed to t...

A detailed kinetic study of hydroxymethylfurfural, lactulose and furosine formation was performed upon heating milk at temperatures between 90 degrees C and 140 degrees C. In case of prolonged heating, formation kinetics could be described by a fractional conversion model. Considering only the first phase of the model, kinetics could be simplified to a pseudo-zero order model. A first assessmen...