Encapsulation of Hazardous Wastes Into Agglomerates (open access)

Encapsulation of Hazardous Wastes Into Agglomerates

The objective of this study was to investigate the feasibility of using the cementitious properties and agglomeration characteristics of coal conversion byproducts to encapsulate and immobilize hazardous waste materials. The intention was to establish an economical way of co-utilization and co-disposal of wastes. In addition, it may aid in the eradication of air pollution problems associated with the fine-powdery nature of fly ash. Encapsulation into agglomerates is a novel approach of treating toxic waste. Although encapsulation itself is not a new concept, existing methods employ high-cost resins that render them economically unfeasible. In this investigation, the toxic waste was contained in a concrete-like matrix whereby fly ash and other cementitious waste materials were utilized. The method incorporates the principles of solidification, stabilization and agglomeration. Another aspect of the study is the evaluation of the agglomeration as possible lightweight aggregates. Since fly ash is commercially used as an aggregate, it would be interesting to study the effect of incorporating toxic wastes in the strength development of the granules. In the investigation, the fly ash self-cementation process was applied to electroplating sludges as the toxic waste. The process hoped to provide a basis for delisting of the waste as hazardous and, thereby …
Date: January 28, 1992
Creator: Guloy, Aida
System: The UNT Digital Library
Synthesis of higher alcohols from carbon monoxide and hydrogen in a slurry reactor (open access)

Synthesis of higher alcohols from carbon monoxide and hydrogen in a slurry reactor

Higher, i.e. C{sub 2{sup +}}, alcohols are desired as gasoline additives, feedstocks for producing ethers and as alternative fuels for automobiles. In all cases, the backbone branching of an alcohol improves octane rating, which is essential for good engine performance. These types of branched, higher alcohols are the desired products for a process converting synthesis gas, a CO and H{sub 2} mixture, often generated from coal gasification. Based on this premise, promoted ZnCr oxide catalysts appear to be as one of the best avenues for further investigation. Once this investigation is complete, a natural extension is to replace the Cr in the ZnCr oxide catalyst with Mo and W, both in the same elemental triad with Cr. Mo has already been shown as an active HAS catalyst, both on a SiO{sub 2} support and in the MoS{sub 2} form. The three catalyst combinations, ZnMo, ZnW, and MnCr oxides will be tested in the stirred autoclave system. However, if none of the three indicate any comparable activity and/or selectivity toward higher alcohols as compared with other HAS catalysts, then an investigation of the effects of Cs promotion on the ZnCr oxide methanol catalysts will be executed.
Date: August 28, 1992
Creator: McCutchen, M. S.
System: The UNT Digital Library
Efficient biased random bit generation for parallel processing (open access)

Efficient biased random bit generation for parallel processing

A lattice gas automaton was implemented on a massively parallel machine (the BBN TC2000) and a vector supercomputer (the CRAY C90). The automaton models Burgers equation {rho}t + {rho}{rho}{sub x} = {nu}{rho}{sub xx} in 1 dimension. The lattice gas evolves by advecting and colliding pseudo-particles on a 1-dimensional, periodic grid. The specific rules for colliding particles are stochastic in nature and require the generation of many billions of random numbers to create the random bits necessary for the lattice gas. The goal of the thesis was to speed up the process of generating the random bits and thereby lessen the computational bottleneck of the automaton.
Date: September 28, 1994
Creator: Slone, D.M.
System: The UNT Digital Library
Two-dimensional NMR investigations of the dynamic conformations of phospholipids and liquid crystals (open access)

Two-dimensional NMR investigations of the dynamic conformations of phospholipids and liquid crystals

None
Date: May 28, 1996
Creator: Hong, Mei
System: The UNT Digital Library
Solid state nuclear magnetic resonance studies of prion peptides and proteins (open access)

Solid state nuclear magnetic resonance studies of prion peptides and proteins

None
Date: August 28, 1997
Creator: Heller, J.
System: The UNT Digital Library