Materials Science and Engineering Commons^™

The Effects Of Electron Radiation On The Glass Transition Temperature Of A Polyetherimide, Kristen Tulloch Kern

Physics Theses & Dissertations

The effects of electron radiation on a polyetherimide (PEI), Ultem*, were investigated. In particular, the changes in the glass transition temperature (T_g) with absorbed radiation dose were studied. The polymer was exposed to mono-energetic beams of 100-keV electrons and 1.0-MeV electrons for doses up to 100 megagray (MGy). Dosimetry for the exposures was based on Monte-Carlo simulations of the transfer of energy from an energetic electron to the polymer and on comparison to Nylon standards. Dynamic mechanical analysis was used to determine the (T_g) for non-exposed PEI and the changes in (T_g) resulting from …

Prediction Of Paper Color: A Process Simulation Approach, Mayank Chaturvedi

Masters Theses

A simulation model was developed for a dye mixing process and for the prediction of the optical properties of the paper. The model was integrated with the MAPPS (Modular Analysis of Pulp and Paper Systems) simulation software package. The model was validated using dyed handsheets made in a laboratory and dyed paper made on a pilot papermachine. Validation comprised of prediction of the optical properties of the handsheets and the machine-made paper which contained various combinations of three non-fluorescent dyes. Sheet reflectances were predicted at 20 nanometer intervals for discrete light wavelength range of 400 to 700 nanometers and verified …

High Temperature Alloys Synthesis By Electro-Discharge Compaction, Kenji Okazaki

Chemical and Materials Engineering Faculty Patents

A method is provided for synthesizing high temperature alloys from elemental powders. The method includes the steps of placing the elemental powders to be processed in a die. A relatively high pressure is then applied to the powders. Substantially simultaneously, an electrical discharge is applied to the powders. The discharge is of relatively high voltage and current density to provide alloying. A product fabricated by the present method is also described and claimed.

Thermal Characterization Of Carbon Monoxide Oxidation Catalysts Using Thermogravimetric Analysts And Differential Scanning Calorimetry, Rene A. Bartgis

Chemistry & Biochemistry Theses & Dissertations

Catalysts composed of platinum and/or palladium on tin (IV) oxide supports, with and without silica gel, as well as catalysts composed of gold on manganese oxide, have been developed for the recombination of carbon monoxide and oxygen to form carbon dioxide for use in carbon dioxide lasers. A thermogravimetric method and a differential scanning calorimetric method have been developed for the thermal characterization of these catalysts. The mass loss data and the enthalpy changes determined as the catalysts lost water were then related to existing activity data for these catalysts. No relationship was found between the thermal data and the …

Solutal Partition Coefficients In Nickel-Based Superalloy Pwa-1480, Surendra N. Tewari, M. Vijayakumar, James E. Lee, P. A. Curreri

Chemical & Biomedical Engineering Faculty Publications

Solutal profiles in dendritic single-crystal specimens of PWA-1480 nickel-base superalloy, which were directionally solidified and quenched, were examined on several transverse cross-sections to obtain the partition coefficients. Similar to their nickel-base binaries, the partition coefficients of tantalum, titanium, and aluminum were found to be less than unity; those of tungsten and cobalt were greater than unity. The partition coefficients were temperature independent in the range 1584-1608 K. The contribution of solid-state diffusion to microsegregation was observed to be negligible.

Removal Of Chlorine From Chlorine-Nitrogen Mixture In A Film Of Liquid Water, Sarwan S. Sandhu

Chemical and Materials Engineering Faculty Publications

In industry there are many examples of absorption of a gas with or without chemical reaction in the liquid phase. In physical absorption, a particular gaseous component is removed from a gas mixture due to its larger solubility in the liquid phase solvent. The removal of butane and pentane from a refinery gas mixture by a heavy oil in the liquid phase is an example of physical absorption. In absorption with chemical reaction, the gaseous component to be removed transfers across the gas-liquid interface due to a difference in the bulk chemical potentials or concentrations in the two phases. The …

Dendrite Spacings In Directionally Solidified Superalloy Pwa-1480, M. Vijayakumar, Surendra N. Tewari, James E. Lee, P. A. Curreri

Chemical & Biomedical Engineering Faculty Publications

Primary dendrite spacings and side-branch coarsening kinetics were examined in specimens of the single-crystal multicomponent commercial superalloy PWA-1480, which were directionally solidified in a positive thermal gradient. The experimentally observed dependence of primary dendrite spacings and side-branch coarsening kinetics on growth rate and thermal gradient were in agreement with the behavior predicted by analytical models developed for binary alloys.

Method Of Processing Superconducting Materials And Its Products, Kenji Okazaki, Robert J. De Angelis, Charles E. Hamrin Jr.

Chemical and Materials Engineering Faculty Patents

A method for fabricating relatively dense monoliths of superconducting material and relatively dense composite monoliths of superconducting material and binder material. The method includes the steps of placing the material to be processed in a die. A relatively high pressure is then applied to the material. Substantially simultaneously, an electrical discharge is applied to the material. The discharge is of a relatively high voltage and current density to provide sharp bonding while maintaining the superconducting properties of the material in the monolith product. A product fabricated by the present method is also described.

Dendrite Tip Radii In Directionally Solidified Pb-8.4-Atmospheric-Percent-Au, Surendra N. Tewari

Chemical & Biomedical Engineering Faculty Publications

The cell/dendrite tip radii in directionally solidified Pb-8.4at.%Au have been investigated as a function of the growth speed and thermal gradient in the liquid at the tip. Dendrite growth models are not able to predict quantitatively the tip radii and tip compositions separately because of the occurrence of thermosolutal convection during growth. However, the relationship between the destabilizing solutal gradient, the stabilizing thermal gradient and the capillarity at the tip assumed using the ''marginal stability'' criterion is supported by the experimental data.

Production Of Anhydrous 1,4-Dioxane, Jean Yamanis

Chemical and Materials Engineering Faculty Patents

This invention relates to the production of anhydrous 1,4-dioxane by the dimerization of ethylene oxide in the presence of an acidic type of cation exchanger, preferably an acidic cation exchanger resin having sulfonic acid groups associated therewith. The 1,4-dioxane is formed by contacting ethylene oxide in the liquid phase with an acidic-type cation exchanger at a first temperature and for a time sufficient to yield a reaction product of the ethylene oxide and the cation exchanger, and thereafter heating the reaction product at a second temperature higher than the first temperature and for a time period sufficient to dissociate the …

The Use Of Thermal Analysis In The Identification And Characterization Of Fibers Of Forensic Interest, Ronald J. Coffey

All-Inclusive List of Electronic Theses and Dissertations

This study investigates the use of thermal analysis for the identification and characterization of fibers for forensic purposes. Fibers such as polyesters, polyacrylics, polypropylenes and nylon were investigated by Differential Thermal Analysis (D.T.A.) and Thermogravimetric Analysis (T.G.A.) to see if their resulting thermograms were characteristic of each fiber. Also, infrared analysis was performed on each fiber. In addition, such factors as heating rate and sample size along with fiber blends were studied as to their effect on thermograms. As a result of this study several important conclusions may be drawn. Although it was found that for the most part D.T.A. …

Inhibitors And Retarders For The Free Radical Polymerization Of Alpha-Methylstyrene, Alexander Accetta

Masters Theses

No abstract provided.

Film Formation On Anodically Polarized Lead, H. Vaidyanathan, Ram A. Narasagoudar, Thomas J. O'Keefe, William Joseph James, James W. Johnson

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

New Genera And Species Of Myripristid Fishes, In The Gulf Coast Cenozoic, Known From Otoliths (Pisces, Beryciformes)

School of Mines and Metallurgy Bulletins

Studies of fossil and Recent otoliths (sagittae) supply an important line of evidence, bearing on classification of teleost fishes, supplementary to that of anatomy, osteology, and "phylogenetic" paleoichthyology.

Squirrelfishes ( " Holocentridae" of authors) are generalized forms in which evolutionary divergence of some mag nitude is reflected in unpreservable details of anatomy, inconspicuous skeletal structures, and striking differentiation of the sagittae. Otoliths show the holocentroid complex to consist of one homogeneous unit (l\fyripristidae, elevated) and another more heterogeneous group (Holocentridae, restricted). These lineages have been separate. at least since the middle Eocene.

A revised classification, based on available lines of …

Crustacean Gastroliths From The Jackson Eocene Of Louisiana

School of Mines and Metallurgy Bulletins

Wechesia louisianae, n. sp., is described from upper Eocene beds at Montgomery, Louisiana. Second species of the genus, it extends the range of Wechesia Frizzell and Exline from Claiborne (middle) Eocene and validates the generic diagnosis.

Spilitic Rocks And Mineral Deposits

School of Mines and Metallurgy Bulletins

The principal results of research work on spilitic rocks and mineral deposits carried on since 1945 are briefly summarized. Emphasis is placed on the influence of the results on the theories of rock and ore genesis, particularly the change of "philosophy of exploration" based on the existence of hydromagmatic ore deposition. A re-classification of magmatic mineral deposits is offered.