Chronopharmacokinetics of rifampicin was studied in four healthy adult male human volunteers after drug (2.0 g) ingestion at 6.00, 12.00, 18.00 and 24.00 hr. The absorption rate constant was found to be lower and the time to reach peak concentration was longer after drug administration at 24.00 hr than at other dosing times. A second peak was observed in all individual volunteers between 6-12 h...

The kinetics of electron attachment to CF(3) as a function of temperature (300-600 K) and pressure (0.75-2.5 Torr) were studied by variable electron and neutral density attachment mass spectrometry exploiting dissociative electron attachment to CF(3)Br as a radical source. Attachment occurs through competing dissociative (CF(3) + e(-) → CF(2) + F(-)) and non-dissociative channels (CF(3) + e(-) ...

The virtual instrument system based on LabVIEW 8.0 for ion analyzer which can measure and analyze ion concentrations in solution is developed and comprises homemade conditioning circuit, data acquiring board, and computer. It can calibrate slope, temperature, and positioning automatically. When applied to determine the reaction rate constant by pX, it achieved live acquiring, real-time displayi...

A generalized kinetic model for fly ash native carbon oxidation is developed. It is shown that the conversion of fly ash native carbon to CO2 is the result of two simultaneous processes taking place on fly ash surface: the first process (rate constant k2) is the direct oxygen transfer from a metal oxide site to a vacant carbon active site leading to immediate carbon gasification; the second one...

T4 DNA ligase catalyzes phosphodiester bond formation between juxtaposed 5'-phosphate and 3'-hydroxyl termini in duplex DNA in three steps: 1) enzyme-adenylylate formation by reaction with ATP; 2) adenylyl transfer to a 5'-phosphorylated polynucleotide to generate adenylylated DNA; and 3) phosphodiester bond formation with release of AMP. This investigation used synthetic, nicked DNA substrates...

     In this study, the stability of trinitroglycerin (TNG) in polyethylene (PEG) 400 was investigated according to Arrhenius approach. The reaction rate constant (k) for the thermal disintegration of TNG in PEG 400 at various temperatures was counted based on the percents of remaining TNG at different intervals of time at a specific temperature. The results showed that “k” at 40, 50, 60, 70, 8...

abstract the aim of this study, is to evaluate the effect of loss methods application on run-off volume and hydrograph shape used by hydrologic models. in this research, four loss methods including constant loss (φ index), initial loss-loss rate, scs and constant fraction approach were applied to be evaluated. to do this, clark rainfall-runoff model was applied for 24 storm events from kasilain...