Now showing items 1-10 of 179
Structural and Synthetic Studies of Potential Antitumor Natural Products
(Virginia Tech, 1998-08-13)
Bioassay directed fractionation of the methyl ethyl ketone extract of Chiloscyphus rivularis yielded eight sesquiterpenoids, and detailed spectroscopic interpretation led to the assignment of their structures as ...
Investigation of the supercritical fluid extraction and detection of metals in contaminated soils
(Virginia Tech, 1996-08-05)
In this work the Supercritical Fluid Extraction (SFE) and detection of sorbed metals in contaminated soils is explored. Iron containing samples were spiked onto sea sand and extracted with Supercritical Fluid CO₂. On-line ...
Effect of chain structure on the thermodynamics and kinetics of polymer crystallization
(Virginia Tech, 1995)
Studies in the stereoselective synthesis of 1,1-disubstituted 1,2,3,4-tetrahydroisoquinolines
(Virginia Tech, 1992-10-06)
Isoquinoline alkaloids and analogs play an important role in today's pharmaceutical industry. The need to synthesize single stereoisomers of these alkaloids is important. Many times only a single stereoisomer exhibits the ...
Equilibrium Melting Temperature Determination of Semicrystalline Polymers through Nonlinear Hoffman-Weeks Extrapolation and Secondary Crystallization of Ethylene/Styrene Copolymers
(Virginia Tech, 1999-10-21)
The applicability of the conventional Hoffman-Weeks (HW) linear extrapolation for the determination of the equilibrium melting temperatures of semicrystalline polymers is critically reviewed. It is shown that the linear ...
Impact of modified carbon dioxide mobile phases on detection on packed-column supercritical fluid chromatography
(Virginia Tech, 1995-10-15)
Modified carbon dioxide mobile phases have been shown to affect both chromatography and detection in packed-column SFC.
Investigation into the quantitative aspects of supercritical fluids as mobile phases for chromatography and extraction
(Virginia Tech, 1990-05-05)
Supercritical fluids were introduced as mobile phases for chromatography and extractions in the early sixties. Over the past decade the technique has received increased attention, largely owing to the introduction of several ...