Resource Type

Investigation of the rank dependence of tar evolution (open access)

Investigation of the rank dependence of tar evolution

The objective of this study are to develop an improved understanding of the process of coal tar evolution, its relationship to the structural characteristics of the parent coal, and the dependence of the chemical and physical properties of the tar products on the conditions of devolatilization. Data from this study are expected to allow hypothesis testing and refinements of coal devolatilization models relevant to the pulverized coal combustion process. A range of coal ranks, from a Texas lignite to a Pennsylvania anthracite, are employed in the investigation. In addition, a high temperature polymer, a polyimide, is utilized as an additional reference case. The polyimide serves as a truly polymeric reference material for examining the nitrogen evolution behavior of coal. The samples are subjected to elemental composition determination, infrared absorbance characterization, calorific value measurement, high temperature ash analysis, and maceral composition. Potential tar yields are determined by long hold time heated grid investigations of each coal at a final temperature and heating rate observed to maximize tar yields for the reference coal. Relative tar evolution kinetic behavior is determined by zero hold time heated grid investigations of each coal. 4 refs., 13 figs., 2 tabs.
Date: January 1, 1990
Creator: Freihaut, J. D. & Proscia, W. M.
System: The UNT Digital Library
Injury experience in stone mining, 1989 (open access)

Injury experience in stone mining, 1989

This Mine Safety and Health Administration (MSHA) informational report reviews in detail occupational injury and illness experience of stone mining in the United States for 1989. Data reported by operators of mining establishments concerning work injuries are summarized by work location, accident classification, part of body injured, nature of injury, occupation, and principal type of mineral. Related information on employment, worktime, and operating activity also is presented. Data reported by independent contractors performing certain work at mining locations are depicted separately in this report. For ease of comparison with other metal and nonmetallic mineral mining industries and with coal mining, summary reference tabulations are included at the end of both the operator and the contractor sections of this report. 3 figs., 46 tabs.
Date: January 1, 1990
Creator: unknown
System: The UNT Digital Library
Ceramic fabrication R D (open access)

Ceramic fabrication R D

This project is separated into three tasks. The first task is a design and modeling effort to be carried out by MSE, Inc. The purpose of this task is to develop and analyze designs for various cohesive ceramic fabrication (CCF) components, including an MHD electrode for strategic defense initiative (SDI) applications and a high stress, low cost, reinforced ceramic component for armor applications. The MHD electrode design is substantially completed. A layered structure composed of molybdenum disilicide graded with quartz glass has been designed and analyzed using finite element methods. The design demonstrates the fabrication capabilities of the CCF process. The high stress, armor application component will be silicon carbide reinforced alumina in thick plates. 2 refs., 4 figs., 1 tab.
Date: January 1, 1990
Creator: unknown
System: The UNT Digital Library
TRW advanced slagging coal combustor utility demonstration (open access)

TRW advanced slagging coal combustor utility demonstration

The TRW Advanced Entrained Coal Combustor Demonstration Project consists of retrofitting Orange and Rockland (O R) Utility Corporation's Lovett Plant Unit No. 3 with four (4) slagging combustors which will allow the gas/oil unit to fire 2.5% sulfur coal. The slagging combustor process will provide NO{sub x} and SO{sub x} emissions that meet NSPS and New York State Environmental Standards. The TRW-Utility Demonstration Unit (UDU) is responsible for the implementation of program policies and overall direction of the project. The following projects will be carried out: process and design development of clean coal technology CCT-1 the development and operation of the entrained coal combustor will enable the boiler to burn low and medium sulfur coal while meeting all the Federal/State emission requirements; demonstrate sulfur dioxide emissions control by pulverized limestone injection into the entrained coal combustor system.
Date: January 1, 1990
Creator: unknown
System: The UNT Digital Library
An alternative approach to disturbances in boundary layers (open access)

An alternative approach to disturbances in boundary layers

By modelling the boundary layer on a flat plate as a piece-wise linear velocity profile it is possible to analyze disturbances in the flow in a systematic manner. The approach is that of an initial-value, boundary-value problem but, unlike classical normal modes employed in stability theory, the solutions here can be obtained in closed form and they are non separable. A specific example is treated where the vertical component of the perturbation velocity is prescribed as a localized pulse initially. The amplitude is then depicted as a function of time and the coordinates of the plane of the flat plate at a fixed vertical location. The role of three-dimensionality and the initial transient period of development -- heretofore unknown -- are both shown to be of significant importance in the dynamics. An argument is given to strongly suggest that the origin of large-scale oscillations known to be prevalent in turbulent shear flows may well be explained using these bases. 15 refs., 8 figs.
Date: January 1, 1990
Creator: Easthope, P.F. & Criminale, W.O.
System: The UNT Digital Library
(Energetics of silicate melts from thermal diffusion studies) (open access)

(Energetics of silicate melts from thermal diffusion studies)

The first year of this three year renewal award has been used to continue data collection and analysis of thermal (Soret) diffusion in silicate liquid and explore the related process of thermal migration in subliquidus magmas and isothermal interdiffusion. Data collection efforts have been materially aided by advances in thermal insulation in the pressure media outside our pressurized cylindrical heaters. BaCO{sub 3} is very effective in protecting the pressure vessel core from thermal deterioration with the result that the heater inside and outside diameters can be substantially increased. This permits several charges to be run simultaneously in an axisymmetric cluster around a double or triple junction thermocouple which can measure axial thermal gradients in situ. Research during the past year has concentrated in four major areas: Modelling thermal diffusion in multi-component silicate liquids, Soret fractionation of major and minor chemical components, characterization of thermal diffusion in naturally-occurring magmas with an emphasis on volatile bearing rhyolitic melts, and the effects of thermal gradients on silicate magma in the melting interval.
Date: January 1, 1990
Creator: unknown
System: The UNT Digital Library
Transport of heavy metals in process wastewaters (open access)

Transport of heavy metals in process wastewaters

This paper focuses on: (1) preparing and analyzing synthetic solutions of resorcinol and copper to simulate waste water results from coal liquefaction processes; (2) analyze the complexes formed between resorcinol and copper to determine coordination numbers, formation constants and other polarographic and electrochemical parameters; and (3) study the extraction efficiency of the aforementioned complex from waste water into removing solvents. The goal of this project is to provide a procedure for systematic separation and removal of resorcinol from coal conversion waste waters based on extractability, formation constants, and acceptable toxic levels. 2 figs.
Date: January 1, 1990
Creator: Wilson, R.F.
System: The UNT Digital Library
US nuclear engineering education: Status and prospects (open access)

US nuclear engineering education: Status and prospects

This study, conducted under the auspices of the Energy Engineering Board of the National Research Council, examines the status of and outlook for nuclear engineering education in the United States. The study resulted from a widely felt concern about the downward trends in student enrollments in nuclear engineering, in both graduate and undergraduate programs. Concerns have also been expressed about the declining number of US university nuclear engineering departments and programs, the aging of their faculties, the appropriateness of their curricula and research funding for industry and government needs, the availability of scholarships and research funding, and the increasing ratio of foreign to US graduate students. A fundamental issue is whether the supply of nuclear engineering graduates will be adequate for the future. Although such issues are more general, pertaining to all areas of US science and engineering education, they are especially acute for nuclear engineering education. 30 refs., 12 figs., 20 tabs.
Date: January 1, 1990
Creator: unknown
System: The UNT Digital Library
(Photoexcited Charge Pair Escape and Recombination) (open access)

(Photoexcited Charge Pair Escape and Recombination)

Progress in four research areas on this project are summarized under the following topics: (1) Geminate charge pair recombination in hexane; (2) Fast current measurements resulting from excitation of charge transfer (CT) states; (3) Measurement of the dipole moment of excited states by DC conductivity; and (4) Charge separation at macroscopic interfaces between electron donor and acceptor solids. In a final section, personnel who have contributed to the project during the past budget period are described.
Date: January 1, 1990
Creator: Braun, C. L.
System: The UNT Digital Library
(Aerodynamic focusing of particles and heavy molecules) (open access)

(Aerodynamic focusing of particles and heavy molecules)

By accelerating a gas containing suspended particles or large molecules through a converging nozzle, the suspended species may be focused and therefore used to write fine lines on a surface. Our objective was to study the limits on how narrow this focal region could be as a function of particle size. We find that, for monodisperse particles with masses m{sub p} some 3.6 {times} 10{sup 5} times larger than the molecular mass m of the carrier gas (diameters above some 100{angstrom}), there is no fundamental obstacle to directly write submicron features. However, this conclusion has been verified experimentally only with particles larger than 0.1 {mu}m. Experimental, theoretical and numerical studies on the defocusing role of Brownian motion for very small particles or heavy molecules have shown that high resolution (purely aerodynamic) focusing is impossible with volatile molecules whose masses are typically smaller than 1000 Dalton. For these, the minimal focal diameter after optimization appears to be 5{radical}(m/m{sub p}) times the nozzle diameter d{sub n}. But combinations of focused lasers and aerodynamic focusing appear as promising for direct writing with molecular precursors. Theoretical and numerical schemes capable of predicting the evolution of the focusing beam, including Brownian motion effects, have been …
Date: January 8, 1990
Creator: de la Mora, J.F.
System: The UNT Digital Library
Magnetohydrodynamic projects at the CDIF (Component Development and Integration Facility) (open access)

Magnetohydrodynamic projects at the CDIF (Component Development and Integration Facility)

This quarterly technical progress report presents the tasks accomplished at the Component Development and Integration Facility during the fourth quarter of FY90. Areas of technical progress this quarter included: coal system development; seed system development; test bay modification; channel power dissipation and distribution system development; oxygen system storage upgrade; iron core magnet thermal protection system oxygen checkout; TRW slag rejector/CDIF slag removal project; stack gas/environmental compliance upgrade; coal-fired combustor support; 1A channels fabrication and assembly; support of Mississippi State University diagnostic testing; test operations and results; data enhancement; data analysis and modeling; technical papers; and projected activities. 2 tabs.
Date: January 1, 1990
Creator: unknown
System: The UNT Digital Library
Correlation of stability/rheology relationship with coal properties and chemical additives (open access)

Correlation of stability/rheology relationship with coal properties and chemical additives

The overall objective of this project is to perform experiments to evaluate the necessary boundary conditions in the preparation and utilization of Coal Water Slurries and also develop a data base for the conceptual analysis of a prescription to predict slurry quality for a given coal candidate.
Date: January 1, 1990
Creator: Ohene, F.
System: The UNT Digital Library
Studies of relativistic heavy ion collisions at the AGS (Experiment 814) (open access)

Studies of relativistic heavy ion collisions at the AGS (Experiment 814)

This report discusses the experimental setup of experiment 814 at Brookhaven AGS. This experiment involves the collision of silicon ions with target nuclei. The detector systems are discussed primarily. (LSP)
Date: January 1, 1990
Creator: Cleland, W.E.
System: The UNT Digital Library
(Comparison of group transfer, inner sphere and outer sphere electron transfer mechanisms of organometallic complexes) (open access)

(Comparison of group transfer, inner sphere and outer sphere electron transfer mechanisms of organometallic complexes)

During the course of Grant ER13775 we have constructed an infrared stopped-flow spectrophotometer and initiated a study of the mechanisms of reactions that involve a change in the oxidation state of organometallic complexes. The spectrometer combined conventional stopped-flow techniques with an infrared optical system comprised of a carbon monoxide laser, an IRTRAN flow-through cell and a mercury-cadium-telluride detector. In this summary we will highlight our results on reactions: (1) that formally involve exchange of a charged species between two metal carbonyl anions, (2) that involve additional of an electron to, or removal of an electron from organometallic complexes that contain a metal-metal bond, and (3) between coordination complexes and metal carbonyl anions. 12 refs.
Date: January 1, 1990
Creator: Atwood, J.
System: The UNT Digital Library
Coherent-state description of free-electron lasers (open access)

Coherent-state description of free-electron lasers

Free-electron lasers (FEL) have great advantages over traditional lasers because they have proved to be by far the most efficient way to generate coherent radiations which are also tunable over the widest range of frequencies. This is made possible by eliminating the middle-man,'' i.e., the atoms, molecules, or crystals in the traditional laser systems. Using quantum mechanical analysis, Maydey first explained the gain mechanism in propagating relativistic electrons through a static periodic magnetic field, the wiggler, of an FEL system. Then the first operative FEL amplifier indicated that the most essential features of FEL can be understood in terms of classical mechanics. However, the problem of photon statistics of FEL and, consequently, the very question of whether or not an FEL is a laser, in the sense that it produces coherent-state radiation, can only be studied quantum mechanically; and coherent properties of a laser beam are very important, especially if it is intended to be transported through a long distance. Furthermore, as the experiments are expanded to new frontiers, it is highly probable that questions will arise which can only be answered by quantum-mechanical description. This research project has been concerned mainly about the quantum aspects of FEL. 8 refs., …
Date: January 1990
Creator: Lee, Ching Tsung (Alabama A and M Univ., Normal, AL (United States))
System: The UNT Digital Library
Double-shell tank space analysis of Hanford Site operating scenarios (open access)

Double-shell tank space analysis of Hanford Site operating scenarios

Several operating cases were evaluated to determine the Hanford Site activities that can be supported given two 242-A Evaporator operating assumption: (1) the evaporator does not restart and (2) the evaporator does not restart until December 1990. These cases included variation in production facility operation and Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement) commitments. The cases that evaluated the no evaporator restart'' operating assumptions determined that even the minimal double-shell tank waste generating activities cannot be supported. For the minimal waste generation rate, double-shell tank space would be depleted by December 1991. The cases that evaluated the evaporator restart would support all production mission with the exception of the plutonium-uranium extraction (PUREX) processing. A delay in the evaporator restart and/or increased waste generation could significantly impact the above conclusions. Actions to reduce waste generation rates, minimize stored volumes in the double-shell tanks, and optimize use of double-shell tanks must be pursued. 1 ref., 8 figs.
Date: January 1, 1990
Creator: McKenney, D. E.; Riley, D. C.; Shaver, R. L. & Strode, J. N.
System: The UNT Digital Library
Johnsonville Fossil Plant (JOF): Supplement to the environmental assessment (EA) for the new ash dredge pond (open access)

Johnsonville Fossil Plant (JOF): Supplement to the environmental assessment (EA) for the new ash dredge pond

In 1989, TVA prepared an EA for development of a new ash dredge pond at JOF. On June 19, 1990, a Finding of No Significant Impact (FONSI) was released which indicated that the project was not considered to be a major federal action significantly affecting the quality of the environment. Since the original EA for this project considered the environmental impacts of only the first phase of construction, the purpose of this supplement is to consider any additional impacts associated with the second phase. It was concluded in the EA that minor air quality impacts (primarily fugitive dust and vehicular emissions) would be created during construction and operation of the first phase of the disposal area. These same impacts would be temporarily created during construction of the second phase of the project. Watering open areas and haul roads and minimization of active areas will reduce fugitive dust. No additional impacts to other environmental media are anticipated from development of the second phase with the exception of potential impacts to groundwater resources. In order to evaluate groundwater impacts of the second phase, groundwater modeling studies conducted in the EA were re-run using estimates based on the conditions expected for the second …
Date: January 1, 1990
Creator: unknown
System: The UNT Digital Library
Activation of oncogenes by radon progeny and x-rays (open access)

Activation of oncogenes by radon progeny and x-rays

The overall goal of this proposal is to study the carcinogenic effect of both high and low LET radiation at the molecular level, utilizing techniques developed in molecular biology, cancer cell biology and radiation biology. The underlying assumption is that malignant transformation of normal cells is a multistep process requiring two or more molecular events in the genomic DNA. We hypothesize that radiation may induce such events in one or more steps of the multistep process. We will use in vitro models of transformation that reproduce the stepwise progression of normal cells toward the transformed phenotype and ask whether radiation can provide the necessary activating function at discrete steps along this path. Our strategy involves transfecting into normal primary cells a variety of cloned oncogenes that are known to supply only some of the functions necessary for full transformation. These partially transformed'' cells will be the targets for irradiation by x-rays and alpha particles. The results will provide the basis for assessing the ability of ionizing radiation to activate oncogenic functions that complement'' the oncogene already present in the transfected cells and produce the fully transformed phenotype. Progress is described. 121 refs.
Date: January 1, 1990
Creator: Ling, C. C.
System: The UNT Digital Library
Configurational Diffusion of Coal Macromolecules (open access)

Configurational Diffusion of Coal Macromolecules

As shown in last quarter's report on the configurational diffusion of coal macromolecules, the hindered diffusion data for both TPP and coal macromolecules were significantly different from the theoretical correlations. In order to evaluate the factors which could lead to this difference an error analysis was conducted, and the detailed results reported herein. Generally, we did not find any errors which could account for the deviation from the theory, and thus we conclude that this deviation is real and can be ascribed to some factor not considered by the hindered diffusion theory, i.e., attractive or repulsive forces. 2 refs., 4 figs., 4 tabs.
Date: January 1, 1990
Creator: Guin, J. A.; Curtis, C. W. & Tarrer, A. R.
System: The UNT Digital Library
Control of fine particulate emissions from coal-fired utility boilers: Spin filter collection device (rotary cyclone) (open access)

Control of fine particulate emissions from coal-fired utility boilers: Spin filter collection device (rotary cyclone)

A bench-scale test program has been performed to evaluate the concept of placing a porous cylindrical surface (such as a metal screen) at the core of a container and spinning the surface with an external motor for fine particulate/gas separation. The rotating surface enhances the centrifugal effects in the annular region and provides a smooth transition between the flow in the annular and core regions and acts like an enhanced cyclone. It is therefore called a rotary cyclone.'' The porous surface is self-cleaning and offers good steady-state pressure drop characteristics. Objectives of this project are: (1) to carry out theoretical and experimental investigations using the rotary cyclone concept to capture particulates in the 0.5 to 10 micron size range; and (2) to evaluate its economic feasibility based on an engineering scale-up and comparison with conventional fabric filter and electrostatic precipitator systems. It was demonstrated that the efficiency in separating fine particulates is governed by two major characteristics, i.e., the magnitude of the centrifugal force and the approach velocity or the gas-to-surface area ratio. Results from the bench-scale tests have shown a collection efficiency of well over 99% for a typical fly ash. A preliminary conceptual design for a 40 MW …
Date: January 1, 1990
Creator: He, Bo X.
System: The UNT Digital Library
Solvent Extraction of Southern U.S. Tar Sands (open access)

Solvent Extraction of Southern U.S. Tar Sands

The Department of Chemical Engineering at the University of Arkansas, in association with Diversified Petroleum Recovery, Inc. (DPR) of Little Rock, Arkansas, has been developing a solvent extraction process for the recovery of bitumen from tar sands for the past five years. The unique feature of the process is that the bitumen is recovered from the solvent by contacting with a co-solvent, which causes the bitumen to precipitate. The overall purpose of this project is to study both the technical and economic feasibility of applying this technology for recovery of bitumen from tar sands by (1) investigating the socioeconmic factors which affect (a) plant siting and (b) the market value of recovered bitumen; (2) operating a process demonstration unit at the rate of 1 lb/hr recovered bitumen while producing clean sand and recyclable solvents; and (3) determine the economic conditions which will make a bitumen recovery project economical. DPR has analyzed the historical trends of domestic production, consumption, discoveries and reserves of crude oil. They have started an investigation of the volatility in the price of crude oil and of gasoline prices and of the differential between gasoline and crude oil. DPR continues to analyze the geographical movement and demand …
Date: January 1, 1990
Creator: Penney, W. R.
System: The UNT Digital Library
Topics in theoretical physics. [High energy physics] (open access)

Topics in theoretical physics. [High energy physics]

This report discusses: covariant, chirally symmetric, confining model of mesons; polarization observables in deuteron photo and electrodisintegration; undetermining the pion form factor at high Q{sup 2}; and model solutions of regularized relativistic transport equations. (LSP)
Date: January 1, 1990
Creator: unknown
System: The UNT Digital Library
Numerical solution of nonlinear algebraic equations in stiff ODE solving (1986--89)---Quasi-Newton updating for large scale nonlinear systems (1989--90) (open access)

Numerical solution of nonlinear algebraic equations in stiff ODE solving (1986--89)---Quasi-Newton updating for large scale nonlinear systems (1989--90)

During the 1986--1989 project period, two major areas of research developed into which most of the work fell: matrix-free'' methods for solving linear systems, by which we mean iterative methods that require only the action of the coefficient matrix on vectors and not the coefficient matrix itself, and Newton-like methods for underdetermined nonlinear systems. In the 1990 project period of the renewal grant, a third major area of research developed: inexact Newton and Newton iterative methods and their applications to large-scale nonlinear systems, especially those arising in discretized problems. An inexact Newton method is any method in which each step reduces the norm of the local linear model of the function of interest. A Newton iterative method is any implementation of Newton's method in which the linear systems that characterize Newton steps (the Newton equations'') are solved only approximately using an iterative linear solver. Newton iterative methods are properly considered special cases of inexact Newton methods. We describe the work in these areas and in other areas in this paper.
Date: January 1, 1990
Creator: Walker, H.F.
System: The UNT Digital Library
Monochromosomal hybrids for the analysis of the human genome (open access)

Monochromosomal hybrids for the analysis of the human genome

In this research project the authors proposed to develop rodent/human hybrid cell lines each containing a single different human chromosome. The human chromosomes will be marked with Ecogpt and stably maintained by selection in the hybrid cells. The experimental approach to produce the proposed cell lines involve the following: they will first transfer a cloned selectable marker, Ecogpt (an E. coli gene for xanthine-guanine phosphoribosyltransferase: XGPRT) to normal diploid human cells using a retroviral vector. The transferred gene will integrate at random into multiple sites in the recipient cell genome. Clonal cell lines from independent transgenotes will each carry the selectable marker integrated into a different site and perhaps a different chromosome. The chromosome carrying the selectable marker will then be transferred further to mouse cells by microcell fusion. In addition they also use directed integration of Ecogpt into the chromosome present in rodent cells, otherwise not marked with a selectable marker. This allows them to complete the bank of proposed cell line. The human chromosome, since it will be marked with a selectable marker, can be transferred to any other cell line of interest for complementation analysis. Clones of each cell line, containing varying size segments of the same …
Date: January 1, 1990
Creator: Athwal, R. S.
System: The UNT Digital Library