Kee-Choo Chung

Viscosity and Volume Effects on Convective Flows in PGSE-NMR Self-Diffusion Measurements at High Temperature

The effects of the sample viscosity and volume on the convective flows induced by temperature gradient in PGSE-NMR self-diffusion measurements at high temperature have been investigated. The experimental results showed that the viscosity of the liquid sample strongly affects the magnitude of the convective flows as well as the diffusion coefficient itself. It was also found that the convective flows increase as the sample volume increase.

Conformational Characteristics of p-tert-Butylcalix(6)arene Mono-Alkyl Ester Derivatives

Conformational properties of several mono-alkyl ester derivatives of p-tert-butylcalix(6)arene depending on temperatures have been investigated by solution NMR spectroscopy. It is found out that all derivatives can adopt a cone-like conformation around room temperature, while the conformational characteristics at high temperatures seem to be quite different each other.