Engineering Science and Materials Commons^™

Scanning Electron Microscopy And X-Ray Energy Dispersive Spectroscopic Analysis Of Selected Sorbent Materials, Elhamy Amin Sedhom

Theses

A previous study⁽¹⁾ showed that a combination of acidic and basic sorbents in a layered system is required to reduce to safe levels the contaminants present in the leachates emanating from industrial landfills. The sorbents used were fly ash, vermiculite, kaolinite, illite, zeolite, apautagite, bentonite, activated carbon and bauxite.

The purpose of this investigation is to study the physical properties, elemental composition and the distribution of the aforementioned solid sorbents. Properties of interest are particle size, shape and distribution and also the chemical composition and the distribution of the elements within the sample particles.

Scanning Electron Microscopy (SEM) and …

High Temperature Resistant Crosslinked Phenol, O-Chlorophenol And Formaldehyde Copolymer Fiber, Suh Joon Han

Theses

Phenolic copolymer fibers which possess clearly distinguishable physical and chemical properties from other synthetic and natural fibers were prepared. Acid catalyzed condensation polymerization of phenol, formaldehyde and o-chiorophenol was carried out by a two-stage polymerization. Initially, phenol-formaldehyde and o-chlorophenol-formaldehyde oligomers were separately prepared by refluxing the corresponding monomers at 100°C under strong agitation. At the second stage, these two oligomers were combined and vacuum-distilled to form a block copolymer which was then melt spinned into fibers and subsequently cured by succinyl chloride in a mineral spirit. Using a flame test and thermogravimetric analysis, it was found that these cured fibers …

Molecular Modeling In Anatoxin And Other Semirigid Agonists, Wen-Chung Shang

Theses

Conformational search and molecular mechanics calculations were combined to investigate the structural flexibility of isoquinolone, the anatoxin series, and the ferruginine series. Ring searching allow all rational conformations to be generated.

Isoquinolone shows conformational similarity to isoarecolone but is much less potent which suggests that the proximity of the methyl group beta to the carbonyl groups affects the bioactivity of isoquinolone. The very active agonist-anatoxin, without a similar conformation as isoarecolone, shared a similar electrostatic potential contour in the vicinity between the two atoms connected to the electro-positive nitrogen and hydrogen bonding site. These phenomena were not found in ferruginine …