A ditopic salt receptor that is known to bind and extract solid NaCl, KCl, NaBr, and KBr into organic solution as their contact ion pairs is now shown by NMR and X-ray crystallography to bind and extract solid LiCl and LiBr as water-separated ion pairs. The receptor can transport these salts from an aqueous phase through a liquid organic membrane with a cation selectivity of K+ > Na+ > Li+. How...

In this paper we calculate the volumes and energies of formation of Schottky defects in the alkali halides NaCl, NaBr, KC1 and KBr. Both the polarisable point-dipole and a simple shell model are evaluated. The calculation uses a generalised and extended Mott-Littleton approach in conjunction with results derived previously by the lattice statics method of Kanzaki. The polarisable point-dipole m...

Laser irradiation on hard tissue has produced a resistant surface that is likely to prevent caries. In this study, human enamel and dentine were exposed to nanosecond pulsed Nd:YAG laser with energy densities of 20-40 J/cm(2) and pulse width of 6 ns inducing chemical changes in these tissues. Infrared analysis of human dental enamel and dentine was performed using the KBr method (2mg sample/300...

1. When B. coli are irradiated by x-rays in a series of salt solutions of tenth molar concentration, the synergistic effect does not become appreciable until heavy salts are used. 2. When Pb(NO(3))(2) or KBr solutions are used in increasing concentrations, the synergistic effect is not appreciable until large concentrations or absorption coefficients are reached, whereupon the effect increases ...

Study of the effect of hydrostatic pressure on the rate of diffusion-limited processes gives in­ formation regarding the intrinsic volume changes associated with formation and motion of defects. While there are basic problems associated with interpretation of the motional volume, such effects may be measured directly in some cases and subtracted to give unambiguous results for the defect format...