States

Enhancing the use of coals by gas reburning-sorbent injection (open access)

Enhancing the use of coals by gas reburning-sorbent injection

The objective of this project is to evaluate and demonstrate a cost effective emission control technology for acid rain precursors, oxides of nitrogen (NO{sub x}) and sulfur (SO{sub x}), on two coal fired utility boilers in Illinois. The units selected are representative of pre-NSPS design practices: tangential and cyclone fired. A third unit, wall fired, is on hold'' because of funding limitations. The specific objectives are to demonstrate reductions of 60 percent in NO{sub x} and 50 percent in SO{sub x} emissions, by a combination of two developed technologies, gas reburning (GR) and sorbent injection (SI). With GR, about 80--85 percent of the coal fuel is fired in the primary combustion zone. The balance of this fuel is added downstream as natural gas to create a slightly fuel rich environment in which NO{sub x} is converted to N{sub 2}. The combustion process is completed by overfire air addition. SO{sub x} emissions are reduced by injecting dry sorbents (usually calcium based) into the upper furnace. The sorbents trap SO{sub x} as solid sulfates that are collected in the particulate control device.
Date: April 16, 1990
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Ornithological Survey of the Proposed Geothermal Well Site No. 2 (open access)

Ornithological Survey of the Proposed Geothermal Well Site No. 2

The U.S. Fish and Wildlife Service (USFWS 1983) and the State of Hawaii (DLNR 1986) have listed as endangered six forest bird species for the Island of Hawaii. Two of these birds, the O'u (Psittirostra psittacea) and the Hawaiian hawk (Buteo solitarius) may be present within the Geothermal resource sub-zone (Scott et al. 1986). Thus, their presence could impact future development within the resource area. This report presents the results of a bird survey conducted August 11 and 12, 1990 in the sub-zone in and around the proposed well site and pad for True/Mid Pacific Geothermal Well No.2.
Date: August 16, 1990
Creator: Jeffrey, Jack
Object Type: Report
System: The UNT Digital Library
Iterative methods for nonsymmetric systems on MIMD machines (open access)

Iterative methods for nonsymmetric systems on MIMD machines

A wide variety of physical phenomena arising within many scientific disciplines can be described by systems of coupled partial differential equations (PDEs). The numerical approximation of these PDEs often involves the solution of a system of algebraic equations (possibly nonlinear) which are typically large, sparse and nonsymmetric. The increasing computational demands required by the solution of such complex scientific applications has motivated the current direction toward large-scale parallel computers. We, therefore, consider solution techniques of representative systems of equations on large scale MIMD machines. Our primary emphasis in this study is the evaluation of iterative methods for the solution of nonsymmetric systems. In particular, we discuss two Krylov subspace methods, the conjugate gradient squared algorithm (CGS) and the generalized minimum residual method (GMRES), along with the multigrid algorithm (MG) on massively parallel MIMD architectures. The focus of this evaluation considers the performance of various algorithm and implementation variations over a broad selection of problems using a parallel machine.
Date: October 16, 1990
Creator: Shadid, J.N. & Tuminaro, R.S.
Object Type: Article
System: The UNT Digital Library
Study of O/Ni(100) with LEED (low-energy electron diffraction) and AES (auger electron spectroscopy) from chemisorption to oxidation (open access)

Study of O/Ni(100) with LEED (low-energy electron diffraction) and AES (auger electron spectroscopy) from chemisorption to oxidation

The structures formed on the Ni(100) surface during oxygen adsorption, leading to oxidation, are studied with Video-LEED (low-energy electron diffraction) and AES (Auger electron spectroscopy). The temperature- and exposure-dependence in the development of LEED patterns observed during oxidation of Ni(100), at oxidation temperatures of 80 to 400 K, are investigated extensively. Integrated diffraction spot intensities and fractional spot profiles are measured quantitatively and continuously, allowing unambiguous correlation of various surface processes. AES is used to measure the oxidation onset during adsorption and the final relative thickness of the oxide. 48 figs., 79 refs.
Date: November 16, 1990
Creator: Wang, Wen-Di.
Object Type: Report
System: The UNT Digital Library
Some observations concerning alpha instabilities and driven tokamak reactors (open access)

Some observations concerning alpha instabilities and driven tokamak reactors

While much research is needed to assess the reality and consequences of alpha-induced instabilities, crude transport estimates for the TAE mode indicate that as little as 10 percent of the alpha energy would be deposited in steady-state. Even so, CIT and the ITER technology phase would meet their minimal goals of Q = 5 if only the alphas themselves are ejected and not the fuel itself. Higher gain up to Q {approximately} 20 may be possible in driven reactors of a different design, depending on the effects of aspect ratio and other geometric features on confinement. Very high gain still requires alpha testing. 5 refs.
Date: July 16, 1990
Creator: Fowler, T.K. (California Univ., Berkeley, CA (USA))
Object Type: Report
System: The UNT Digital Library
The theory of temporal compression of intense pulses in a metal vapor (open access)

The theory of temporal compression of intense pulses in a metal vapor

We examine compression of near-resonant pulses in metal vapor in the nonlinear regime. Our calculations examine nonlinear effects on compression of optimally-chirped pulses of various fluences. In addition, we compare model predictions with experimental results for compression of 4 nsec Nd:YAG pumped dye pulses.
Date: November 16, 1990
Creator: Shaw, M.J. & Crane, J.K.
Object Type: Article
System: The UNT Digital Library
First-principles study of the contractive reconstruction of gold and silver monolayers on gold, silver and aluminum (open access)

First-principles study of the contractive reconstruction of gold and silver monolayers on gold, silver and aluminum

Using first-principles calculations in conjunction with modeling techniques, the author has investigated the structures of Au and Ag monolayers on a number of metal surfaces. Au(100) has a c(26 {times} 68) surface unit cell and the reconstruction has been interpreted as the top layer transforming to a contracted hexagonal-close-packed layer, superimposed on the square lattice of the underlying substrate atoms. Similar reconstructions have been observed on the 5d fcc metals Ir and Pt, but not in the 4d Rh, Pd, and Ag. The author studied the energetics of a monolayer of Au and Ag using first-principles calculations. The author found that it is energetically favorable for both Au and Ag to transform from a square to hexagonal arrangement and to contract to a higher surface density, but Au gains substantially more energy than Ag. This is true both for a monolayer in isolation as well as on top of a jellium surface. The author also calculated the mismatch energy (energy loss when the top layer loses registry with the substrate) for Au and Ag, and found that Ag has a slightly higher mismatch energy. The first-principles results thus offer a strong indication that Au(100) can reconstruct but Ag will not. …
Date: November 16, 1990
Creator: Takeuchi, Noboru.
Object Type: Report
System: The UNT Digital Library
Massively parallel Fokker-Planck calculations epilogue (open access)

Massively parallel Fokker-Planck calculations epilogue

The purpose of this writeup is to supplement the publication, Massively Parallel Fokker-Planck Calculations,'' which appeared in the Proceedings of the Fifth Distributed Memory Computing Conference. Results obtained subsequent to that presentation are reported. This work is not self-contained; the reader should refer to that publication.
Date: October 16, 1990
Creator: Mirin, A. A.
Object Type: Report
System: The UNT Digital Library
Photoion-photoelectron coincidence studies clusters and transient molecules (open access)

Photoion-photoelectron coincidence studies clusters and transient molecules

Experimental photoion-photoelectron coincidence (PIPECO) spectra have been obtained at different nozzle stagnation pressures for Ar, Kr, Xe, and CO dimers and trimers in the wavelength regions corresponding to the respective ground states through all states accessible with a photon energy of 20 eV. Ionization energies for all ground states were measured and agree well with previously reported values. The formation of stable dimer ions from fragmentation of larger cluster ions initially produced by photoionization is efficient. For nozzle expansion conditions which minimize the formation of clusters larger than dimers, the intensities of the excited PIPECO bands for all clusters, except Ar{sub 2}{sup +} and Ar{sub 3}{sup +}, are found to be negligible with respect to the ground state PIPECO bands. The PIPECO technique has been used successfully to obtain the mass-selected threshold photoelectron spectra of the SO and S{sub 2}O transient molecules formed from a microwave discharge, effusive beam source. Analysis of the PIPECO spectra of all the clusters and transient molecules are presented. 177 refs., 32 figs., 6 tabs.
Date: November 16, 1990
Creator: Norwood, K.
Object Type: Report
System: The UNT Digital Library
Measuring the efficacy of a root biobarrier with x-ray computed tomography (open access)

Measuring the efficacy of a root biobarrier with x-ray computed tomography

X-ray computed tomography is a useful tool for investigating soil physical properties nondestructively. There is a need to develop proper calibration relationships between soil properties and the x-ray absorption coefficient. The objective of the work was to evaluate soil factors affecting the x-ray absorption coefficient. Based on a theoretical analysis, experimental data from five soils and on results of several other investigators, it was concluded that for many applications, one calibration relationship is applicable to a wide range of soils. The montmorillinitic clay used in the study required special handling due to the extreme shrinkage of this soil upon drying. Knowledge of chemical composition enables approximations but not exact predictions of the x-ray absorption coefficient. The results suggested some reasonable alternative to exhaustive calibration for each anticipated soil condition. Quantification of root activity in terms of root growth and indirectly through water uptake is necessary for understanding plant growth dynamics. X-ray computed tomography (CT) enables qualitative as well as two quantitative outputs, one of which can lead to conclusions regarding root activity. A greenhouse study involving soil columns (Lakeland sand, bulk density 1.4 Mg/m{sup 3}) planted to soybean, Bahiagras, and control (no vegetation) was conducted in 1989. A treflan based …
Date: August 16, 1990
Creator: Tollner, E. W. & Murphy, C. E. Jr.
Object Type: Report
System: The UNT Digital Library
Laser pulse compression in strontium and calcium vapor (open access)

Laser pulse compression in strontium and calcium vapor

Application of vapor pulse compression for increasing the intensity of a large copper vapor laser pumped dye laser for x-ray generation is limited by collisional absorption and nonlinear pulse breakup. We discuss measurements of these effects. 7 refs., 1 fig., 11 tabs.
Date: November 16, 1990
Creator: Crane, J. K.; Cooke, J. D.; Shaw, M. J.; Presta, R. W.; Christensen, J. J.; Johnson, M. A. et al.
Object Type: Article
System: The UNT Digital Library
Fast Shutdown System tests in the Georgia Tech Research Reactor (open access)

Fast Shutdown System tests in the Georgia Tech Research Reactor

The Fast Shutdown System (FSS) is a new safety system design concept being considered for in installation in the Savannah River (SRS) production reactors. This system is expected to mitigate the consequences of a Design Basis Loss of Coolant Accident, and therefore allow higher operational power levels. A test of this system in the Georgia Tech Research Reactor is proposed to demonstrate the efficacy of this concept. Three tests will be conducted at full power (5MW) and one at low power (100kw). Two full power tests will be conducted with the FSS rod backfilled with one (1) atmosphere of He-4, and one with the rod evacuated. The low power conducted with the FSS rod evacuated. Neutron flux and pressure data will be collected with an independent data acquisition system (DAS). Safety issues associated with the performance of the Fast Shutdown System experiments are addressed in this report. The credible accident scenarios were analyzed using worst case scenarios to demonstrate that no significant nuclear or personnel safety hazards would result from the performance of the proposed experiments.
Date: March 16, 1990
Creator: Wallace, J.M.
Object Type: Report
System: The UNT Digital Library
The structure and properties of grain boundaries in B2 ordered alloys (open access)

The structure and properties of grain boundaries in B2 ordered alloys

This report covers the period from April 1, 1989 to March 30, 1990. During this period further extrusions of fine-grained alloys of FeAl and NiAl with different aluminum contents were produced. Thus far, researchers have (1) completed room temperature mechanical testing which shows that the yield strength, {sigma}{sub y}, of FeAl shows a minimum near Fe-45Al while that for NiAl increases with increasing (nickel-rich) deviation from stoichiometry; (2) showed that the grain boundary strengthening parameter, k, in the Hall-Petch relationship, {sigma}{sub y} = {sigma}{sub 0} + k d{sup {minus}{1/2}} (where {sigma}{sub 0} is the lattice resistance and d the grain size), in FeAl shows a minimum at Fe-45Al whilst in NiAl it decreases with increasing deviation from stoichiometry; (3) studied grain boundary chemistry in near-stoichiometric NiAl and FeAl using scanning Auger electron spectroscopy at Oak Ridge National Laboratory, with the aid of Mr. R.A. Padgett, Jr.; studied grain boundary chemistry using EDS and Z-contrast imaging on field emission gun high resolution scanning transmission electron microscopes; (5) continued in-situ straining experiments in the transmission electron microscope to examine dislocation/grain boundary interactions; (6) examined dislocation structures in lightly-deformed NiAl and FeAl and, based on observations in the latter, proposed a mechanism for …
Date: April 16, 1990
Creator: Baker, I.
Object Type: Report
System: The UNT Digital Library
The spatial evaluation of neighborhood clusters of birth defects (open access)

The spatial evaluation of neighborhood clusters of birth defects

Spatial statistics have recently been applied in epidemiology to evaluate clusters of cancer and birth defects. Their use requires a comparison population, drawn from the population at risk for disease, that may not always be readily available. In this dissertation the plausibility of using data on all birth defects, available from birth defects registries, as a surrogate for the spatial distribution of all live births in the analysis of clusters is assessed. Three spatial statistics that have been applied in epidemiologic investigations of clusters, nearest neighbor distance, average interpoint distance, and average distance to a fixed point, were evaluated by computer simulation for their properties in a unit square, and in a zip code region. Comparison of spatial distributions of live births and birth defects was performed by drawing samples of live births and birth defects from Santa Clara County, determining the street address at birth, geocoding this address and evaluating the resultant maps using various statistical techniques. The proposed method was then demonstrated on a previously confirmed cluster of oral cleft cases. All live births for the neighborhood were geocoded, as were all birth defects. Evaluation of this cluster using the nearest neighbor and average interpoint distance statistics was …
Date: April 16, 1990
Creator: Frisch, J. D.
Object Type: Report
System: The UNT Digital Library
The alias method: A fast, efficient Monte Carlo sampling technique (open access)

The alias method: A fast, efficient Monte Carlo sampling technique

The alias method is a Monte Carlo sampling technique that offers significant advantages over more traditional methods. It equals the accuracy of table lookup and the speed of equal probable bins. The original formulation of this method sampled from discrete distributions and was easily extended to histogram distributions. We have extended the method further to applications more germane to Monte Carlo particle transport codes: continuous distributions. This paper presents the alias method as originally derived and our extensions to simple continuous distributions represented by piecewise linear functions. We also present a method to interpolate accurately between distributions tabulated at points other than the point of interest. We present timing studies that demonstrate the method's increased efficiency over table lookup and show further speedup achieved through vectorization. 6 refs., 2 figs., 1 tab.
Date: November 16, 1990
Creator: Rathkopf, James A.; Edwards, Arthur L. & Smidt, Rorbert K.
Object Type: Article
System: The UNT Digital Library
Radiation Laboratory, University of Notre Dame (open access)

Radiation Laboratory, University of Notre Dame

The Notre Dame Radiation Laboratory is a facility of the Department of Energy operated for DOE by the University of Notre Dame. The majority of the programs within the Laboratory are supported by the Office of Basic Energy Sciences of DOE and, unless otherwise noted in the following, support can be attributed to the Office of Basic Energy Sciences. Certain additional programs, so indicated, are supported by the Office of Standard Reference Data of the National Institute of Standards and Technology. Research programs conducted at the laboratory are briefly described.
Date: October 16, 1990
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Solving the Fokker-Planck equation on a massively parallel computer (open access)

Solving the Fokker-Planck equation on a massively parallel computer

The Fokker-Planck package FPPAC had been converted to the Connection Machine 2 (CM2). For fine mesh cases the CM2 outperforms the Cray-2 when it comes to time-integrating the difference equations. For long Legendre expansions the CM2 is also faster at computing the Fokker-Planck coefficients. 3 refs.
Date: October 16, 1990
Creator: Mirin, A. A.
Object Type: Article
System: The UNT Digital Library
(Boiling water reactor (BWR) CORA experiments) (open access)

(Boiling water reactor (BWR) CORA experiments)

To participate in the 1990 CORA Workshop at Kernforschungszentrum Karlsruhe (KfK) GmbH, Karlsruhe, FRG, on October 1--4, and to participate in detailed discussions on October 5 with the KfK CORA Boiling Water Reactor (BWR) experiments. The traveler attended the 1990 CORA Workshop at KfK, FRG. Participation included the presentation of a paper on work performed by the Boiling Water Reactor Core Melt Progression Phenomena Program at Oak Ridge National Laboratory (ORNL) on posttest analyses of CORA BWR experiments. The Statement of Work (November 1989) for the BWR Core Melt Progression Phenomena Program provides for pretest and posttest analyses of the BWR CORA experiments performed at KfK. Additionally, it is intended that ORNL personnel participate in the planning process for future CORA BWR experiments. For these purposes, meetings were held with KfK staff to discuss such topics as (1) experimental test schedule, (2) BWR test conduct, (3) perceived BWR experimental needs, and (4) KfK operational staff needs with respect to ORNL support. 19 refs.
Date: October 16, 1990
Creator: Ott, L.J.
Object Type: Report
System: The UNT Digital Library
Texas Register, Volume 15, Number 79, Pages 6045-6088, October 16, 1990 (open access)

Texas Register, Volume 15, Number 79, Pages 6045-6088, October 16, 1990

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.
Date: October 16, 1990
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Texas Register, Volume 15, Number 86, Pages 6541-6629, November 16, 1990 (open access)

Texas Register, Volume 15, Number 86, Pages 6541-6629, November 16, 1990

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.
Date: November 16, 1990
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Texas Register, Volume 15, Number 21, Pages 1427-1548, March 16, 1990 (open access)

Texas Register, Volume 15, Number 21, Pages 1427-1548, March 16, 1990

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.
Date: March 16, 1990
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Texas Register, Volume 15, Number 13, Pages 789-904, February 16, 1990 (open access)

Texas Register, Volume 15, Number 13, Pages 789-904, February 16, 1990

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.
Date: February 16, 1990
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Texas Register, Volume 15, Number 5, Pages 241-290, January 16, 1990 (open access)

Texas Register, Volume 15, Number 5, Pages 241-290, January 16, 1990

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.
Date: January 16, 1990
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Texas Attorney General Opinion: JM-1156 (open access)

Texas Attorney General Opinion: JM-1156

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Jim Mattox, regarding a legal question submitted for clarification: Child care facilities in building owned or leased by the State of Texas (RQ-1905)
Date: April 16, 1990
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History