The prtnonation constant values of tryptophan were studied at 25 C. different ionic strengths. 0.1-1.0 moldm", and various ionic media of NaCIO, and N4N01, using a combination of spectrophotometrie andpotentiometric techniques. The general vend for the two protonation con Slant Vai net of tryptophan is in theorder of NaC104 > NaNO3 in different ionic media. The dependence of protonation constan...

H3 plays a key role in interstellar chemistry as the initiator of ion–molecule chemistry. The amount of H3 observed in dense interstellar clouds is consistent with expectations, but the large abundance of H3 seen in diffuse clouds is not easily explained by simple chemical models. A crucial parameter in predicting the abundance of H3 in diffuse clouds is the rate constant for dissociative recom...

The quenching constant for the iodide quenching of the fluorescence of riboflavin phosphate was measured at pH 5 and at pH 8. The value of the constant at the lower pH (where the phosphate group is unionized), k' = 23 M~ , was independent of the ionic strength, |i. The ratio k"/k' = f (k" the quenching constant at pH 8, where the phosphate group carries a single negative charge) was found to he...

This straightforward extension of the T = 0 renormalizat ion group ( R G ) results is not completely satisfactory. In ref. [ 2 ], Matsumoto et al. generalize the RG approach at finite T i n the framework of the real t ime formalism [3]. In this framework, the ultraviolet divergences are the same as at T = 0 but in addit ion to the freedom of choosing the usual m o m e n t u m renormalizat ion p...

The ion-sensitive field-effect transistor (ISFET) that is designed to detect a specific ionic activity is susceptible to interfering ions in mixed-ion environments causing the sensor to produce deceptive signals. The objective of this work is to improve the interpretation of ISFET signals in mixed-ion environments. The focus of the research is relating sensor signal to the targeted ion concentr...

The collision frequency should definitely be taken into account in high pressure discharges. In this work by using forth order of Rung Kuta method, and two-fluid model, temperature dependence of the characteristics of a collisional DC plasma sheath, such as electric field, electric potential, ion and electron number density, and ion velocity, has been studied. It will be shown in the constant c...

The motion of an ion bunch trapped between two electrostatic mirrors in an ion-trap resonator is analyzed both experimentally and via numerical simulations. It is found that under certain conditions it is possible to achieve either synchronization of the ion motion, which causes the size of the bunch to remain constant, or enhanced diffusion, which leads to rapid debunching. These effects are a...

A spectrophotometric method has been used to determ in e the dissociat ion constants of o-chloroanilinium ion, m-n itroanilini um ion , and 4-chloro-2,6-din itrophenol in methanolwater solvents at 25 °C. The ranges of solvent composition s (in weigh t percent metha nol) were as follows: o-ehloroan ilinium ion , 0 to 99.9; ?n-nitroanilinium ion, 0 to 93.7; and 4-ehloro-2,6-dinitrophenol, 0 to 33...

A concept for a charge state multiplier, to be used for the production of energetic radioactive ion beams based on the ISOL+post-accelerator system, is discussed. The charge state breeder implies external ion injection into an Electron Beam Ion Source (EBIS). The total efficiency, measured by injecting a low-energy nitrogen (Q=1+ ) beam, reached 14.5% and was essentially constant for confinemen...