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. Work on 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{endash}85 percent of the coal fuel is fired in the primary combustion zone. The balance of the 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: July 19, 1990
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Development of improved iron Fischer-Tropsch catalysts (open access)

Development of improved iron Fischer-Tropsch catalysts

The objective of proposed research is development of catalysts with enhanced slurry phase activity and better selectivity to fuel range products, through a more detailed understanding and systematic studies of the effects of pretreatment procedures and promoters/binders (silica) on catalyst performance.
Date: July 19, 1991
Creator: Bukur, D.B.
Object Type: Report
System: The UNT Digital Library
Ground wave propagation of a video pulse source: Part 2 (open access)

Ground wave propagation of a video pulse source: Part 2

In a previous paper we developed a simple model describing the far-field from a video-pulse source near the ground and for grazing incidence. We report here on a recent field test in which we attempted to verify the model. Our results show quantitative agreement with the model for most of the tested parameter space. We have also extended our model to include all elevation angles, including up to vertical. The computed engagement envelope shows three distinct regions: At grazing angles the field is small and diminishes to near zero at the earth's surface; at low-to moderate angles strong lobing occurs; at high angles the video-pulse field approaches its free-space form. 6 refs., 16 figs.
Date: July 19, 1991
Creator: Dreyer, K. A. & Buettner, H. M.
Object Type: Report
System: The UNT Digital Library
Housing Finance: Budget Savings From the Sale of HUD Loans (open access)

Housing Finance: Budget Savings From the Sale of HUD Loans

A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO the reviewed the reasonableness of the: (1) Department of Housing and Urban Development's (HUD) estimates of budgetary savings from the sale of its single-family loans; and (2) model HUD used to estimate savings from the sale of multifamily loans."
Date: July 19, 1999
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library
DOD Contract Management: Greater Attention Needed to Identify and Recover Overpayments (open access)

DOD Contract Management: Greater Attention Needed to Identify and Recover Overpayments

A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO updated its previous report on the Department of Defense's (DOD) overpayments to contractors and subsequent refunds to the Defense Finance Accounting Service (DFAS), focusing on: (1) DOD's efforts to identify and recover overpayments made through fiscal year (FY) 1998; and (2) whether 13 contractors were retaining overpayments and how quickly overpayments were refunded."
Date: July 19, 1999
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library
Texas Register, Volume 16, Number 54, Pages 3967-4030, July 19, 1991 (open access)

Texas Register, Volume 16, Number 54, Pages 3967-4030, July 19, 1991

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: July 19, 1991
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Texas Register, Volume 19, Number 53, Pages 5557-5664, July 19, 1994 (open access)

Texas Register, Volume 19, Number 53, Pages 5557-5664, July 19, 1994

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: July 19, 1994
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Texas Register, Volume 21, Number 53, Pages 6739-6854, July 19, 1996 (open access)

Texas Register, Volume 21, Number 53, Pages 6739-6854, July 19, 1996

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: July 19, 1996
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Texas Attorney General Opinion: JM-1187 (open access)

Texas Attorney General Opinion: JM-1187

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: Eligibility of a realtor to serve on the board of directors of an appraisal district (RQ-1880)
Date: July 19, 1990
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: LO90-45 (open access)

Texas Attorney General Opinion: LO90-45

Letter opinion 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; Whether an individual may serve simultaneously as chief of an appraisal district and chairman of the appraisal district's board of directors.
Date: July 19, 1990
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Thermal effects on the STAR electromagnetic calorimeter (open access)

Thermal effects on the STAR electromagnetic calorimeter

The STAR detector for the RHIC colliding beam accelerator is under construction at Brookhaven National Laboratory. This detector will consist of a number of subsystems. These include a silicon vertex detector (SVT) for charged particle tracks near the interaction region, a time projection chamber (TPC) for charged particle tracking, an array of plastic scintillation counters (CTB) in a layer around the TPC for triggering on charged particles, a conventional solenoidal magnet, and some additional small triggering detectors along the beam-line. An electromagnetic calorimeter (EMC) is an upgrade to the ``baseline`` detector configuration above. The conventional magnet and numerous electronic channels for the SVT and TPC subsystems will generate a considerable amount of heat during the operation of STAR. However, it is possible that a chiller for the magnet cooling water will not be available during some of the early STAR runs. As a result, the average magnet temperature may vary considerably between winter and summer. This note summarizes calculations and measurements performed to evaluate the effects of an elevated magnet temperature on the performance of the electromagnetic calorimeter.
Date: July 19, 1994
Creator: Fornek, T.; Guarino, V.; Spinka, H. & Underwood, D.
Object Type: Report
System: The UNT Digital Library
Enhancing the use of coals by gas reburning-sorbent injection. Quarterly report No. 11, April 1--June 30, 1990 (open access)

Enhancing the use of coals by gas reburning-sorbent injection. Quarterly report No. 11, April 1--June 30, 1990

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. Work on 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{endash}85 percent of the coal fuel is fired in the primary combustion zone. The balance of the 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: July 19, 1990
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Core-level spectroscopy of thin oxides and oxynitrides (open access)

Core-level spectroscopy of thin oxides and oxynitrides

Several spectroscopic methods are discussed that use core levels, such as photoelectron spectroscopy and absorption spectroscopy with photoelectron or fluorescence detection. Measurements are presented on the desorption of a chemical oxide and the growth of oxynitrides with N{sub 2}0 on Si(100). The stoichiometry is found to change strongly with thickness, from a nitrogen-terminated Si surface to a nearly-pure oxide in the outer region of 40--60 {Angstrom} films. Using a third generation synchrotron beam line a sensitivity of better than a tenth of a monolayer is achieved by a simple photocurrent measurement.
Date: July 19, 1994
Creator: Himpsel, F. J.; Akatsu, H. & Carlisle, J. A.
Object Type: Article
System: The UNT Digital Library
Integrated low emissions cleanup system for direct coal fueled turbines (moving bed, fluid bed contactor/ceramic filter). Twenty-third quarterly status report, April--June 1993 (open access)

Integrated low emissions cleanup system for direct coal fueled turbines (moving bed, fluid bed contactor/ceramic filter). Twenty-third quarterly status report, April--June 1993

The United States Department of Energy, Morgantown Energy Research Center (DOE/METC), is sponsoring the development of direct coal-fired turbine power plants as part of their Heat Engines program. A major technical challenge remaining for the development of the direct coal-fired turbine is high-temperature combustion gas cleaning to meet environmental standards for sulfur oxides and particulate emissions, as well as to provide acceptable turbine life. The Westinghouse Electric Corporation, Science & Technology Center, is evaluating two Integrated Low Emissions Cleanup (ILEC) concepts that have been configured to meet this technical challenge: A baseline ceramic barrier filter ILEC concept, and a fluidized bed ILEC concept. These ILEC concepts simultaneously control sulfur, particulate, and alkali contaminants in the high-pressure combustion gases at turbine inlet temperatures up to 2300{degrees}F. This document reports the status of a program in the nineteenth quarter to develop this ILEC technology for direct coal-fired turbine power plants.
Date: July 19, 1993
Creator: Newby, R. A.; Alvin, M. A.; Bachovchin, D. M.; Yang, W. C.; Smeltzer, E. E. & Lippert, T. E.
Object Type: Report
System: The UNT Digital Library
Development of improved iron Fischer-Tropsch catalysts. Quarterly technical progress report, 1 April 1991--30 June 1991 (open access)

Development of improved iron Fischer-Tropsch catalysts. Quarterly technical progress report, 1 April 1991--30 June 1991

The objective of proposed research is development of catalysts with enhanced slurry phase activity and better selectivity to fuel range products, through a more detailed understanding and systematic studies of the effects of pretreatment procedures and promoters/binders (silica) on catalyst performance.
Date: July 19, 1991
Creator: Bukur, D. B.
Object Type: Report
System: The UNT Digital Library
Hanford emergency management plan - release 15 (open access)

Hanford emergency management plan - release 15

The Hanford emergency management plan for the US Department of Energy Richland, WA and Office of River Protection. The program was developed in accordance with DOE Orders as well as Federal and State regulations to protect workers and public health and safety.
Date: July 19, 1999
Creator: CARPENTER, G.A.
Object Type: Report
System: The UNT Digital Library
Organic end state analysis of tank 241-U-103 (open access)

Organic end state analysis of tank 241-U-103

This document provides a record of the organic end state analysis of tank 2414-103. Tank 241-U-103 is one of twelve 22.9-meter (75-feet) diameter single-shell tanks in the 241-U Tank Farm in the 200 West Area of Hanford. This tank was built in 1943-1944 and has a capacity of 2,006 kiloliter (E) (530 kilogallon [kgal]). According to Hanlon (1999), tank 241-U-103 currently contains 1840 kL (468 kgal) of waste comprised of 1639 kL (443 kgal) saltcake, 45 kL (12 kgal) sludge, and 49 kL (13 kgal) Supernatant. Included in those volumes is 867 kL (229 kgal) drainable liquid. The pumpable volume is estimated at 825 kL (218 kgal). The waste is designated as non-complexed (NCPLX). Tank 241-U-103 is a flammable gas Watch List tank. Tank 241-U-103 has not been declared as a leaker.
Date: July 19, 1999
Creator: FOWLER, K.D.
Object Type: Report
System: The UNT Digital Library
Radcalc for windows benchmark study: A comparison of software results with Rocky Flats hydrogen gas generation data (open access)

Radcalc for windows benchmark study: A comparison of software results with Rocky Flats hydrogen gas generation data

Radcalc for Windows Version 2.01 is a user-friendly software program developed by Waste Management Federal Services, Inc., Northwest Operations for the U.S. Department of Energy (McFadden et al. 1998). It is used for transportation and packaging applications in the shipment of radioactive waste materials. Among its applications are the classification of waste per the US. Department of Transportation regulations, the calculation of decay heat and daughter products, and the calculation of the radiolytic production of hydrogen gas. The Radcalc program has been extensively tested and validated (Green et al. 1995, McFadden et al. 1998) by comparison of each Radcalc algorithm to hand calculations. An opportunity to benchmark Radcalc hydrogen gas generation calculations to experimental data arose when the Rocky Flats Environmental Technology Site (RFETS) Residue Stabilization Program collected hydrogen gas generation data to determine compliance with requirements for shipment of waste in the TRUPACT-II (Schierloh 1998). The residue/waste drums tested at RFETS contain contaminated, solid, inorganic materials in polyethylene bags. The contamination is predominantly due to plutonium and americium isotopes. The information provided by Schierloh (1 998) of RFETS includes decay heat, hydrogen gas generation rates, calculated G{sub eff} values, and waste material type, making the experimental data ideal for …
Date: July 19, 1999
Creator: MCFADDEN, J.G.
Object Type: Article
System: The UNT Digital Library
Silicon Nitride Membranes for Filtration and Separation (open access)

Silicon Nitride Membranes for Filtration and Separation

Semi-Permeable silicon nitride membranes have been developed using a Bosch etch process followed by a reactive ion etch (NE) process. These membranes were observed to allow air but not water to pass through them into surface micromachined, silicon nitride microfluidic channels. Membranes with this property have potential use in microfluidic systems as gas bubble traps and vents, filters to remove particles and gas partitioning membranes. Membrane permeation was measured as 1.6 x 10{sup {minus}8} mol/m{sup 2}Pa s of helium for inline membranes at the entrance and exit of the silicon nitride microfluidic channels.
Date: July 19, 1999
Creator: Galambos, Paul; Zavadil, Kevin; Shul, Randy; Willison, Christi Gober & Miller, Sam
Object Type: Article
System: The UNT Digital Library
Conversion of Phase II Unsteady Aerodynamics Experiment Data to Common Format (open access)

Conversion of Phase II Unsteady Aerodynamics Experiment Data to Common Format

A vast amount of aerodynamic, structural, and turbine performance data were collected during three phases of the National Renewable Energy Laboratory's Unsteady Aerodynamics Experiment (UAE). To compare data from the three phases, a similar format of engineering unit data is required. The process of converting Phase II data from a previous engineering unit format to raw integer counts is discussed. The integer count files can then be input to the new post-processing software, MUNCH. The resulting Phase II engineering unit files are in a common format with current and future UAE engineering unit files. An additional objective for changing the file format was to convert the Phase II data from English units to SI units of measurement.
Date: July 19, 1999
Creator: Hand, M. M.
Object Type: Report
System: The UNT Digital Library
Cooperation Between the Russia Federation and the United States to Enhance the Existing Nuclear-Material Protection, Control, and Accounting Systems at Mayak Production Association (open access)

Cooperation Between the Russia Federation and the United States to Enhance the Existing Nuclear-Material Protection, Control, and Accounting Systems at Mayak Production Association

The Ministry of the Russian Federation for Atomic Energy (MINATOM) and the US Department of Energy (DOE) are engaged in joint, cooperative efforts to reduce the likelihood of nuclear proliferation by enhancing Material Protection, Control and Accounting (MPC&A) systems in both countries. Mayak Production Association (Mayak) is a major Russian nuclear enterprise within the nuclear complex that is operated by lylINATOM. This paper describes the nature, scope, and status of the joint, cooperative efforts to enhance existing MPC&A systems at Mayak. Current cooperative efforts are focused on enhancements to the existing MPC&A systems at two of the plants operated by Mayak that work with proliferation-sensitive nuclear materials.
Date: July 19, 1999
Creator: Cahalane, P. T.; Ehinger, M. H.; James, L. T.; Jarrett, J. H.; Lundgren, R. A.; Manatt, D. R. et al.
Object Type: Article
System: The UNT Digital Library
How the K(d) Approach Undermines Groundwater Cleanup (open access)

How the K(d) Approach Undermines Groundwater Cleanup

Environmental scientists have long appreciated that the distribution coefficient (the ''K{sub d}'' or ''constant K{sub d}'') approach predicts the partitioning of heavy metals between sediment and groundwater inaccurately; nonetheless, transport models applied to problems of environmental protection and groundwater remediation almost invariably employ this technique. To examine the consequences of this practice, we consider transport in one dimension of Pb and other heavy metals through an aquifer containing hydrous ferric oxide, onto which heavy metals sorb strongly. We compare the predictions of models calculated using the K{sub d} approach to those given by surface complexation theory, which is more realistic physically and chemically. The two modeling techniques give qualitatively differing results that lead to divergent cleanup strategies. The results for surface complexation theory show that water flushing is ineffective at displacing significant amounts of Pb from the sorbing surface. The effluent from such treatment contains a ''tail'' of small but significant levels of contamination that persists indefinitely. Subsurface zones of Pb contamination, furthermore, are largely immobile in flowing groundwater. These results stand in sharp contrast to the predictions of models constructed using the k{sub d} approach, yet are consistent with experience in the laboratory and field.
Date: July 19, 1999
Creator: Bethke, Craig M. & Brady, Patrick V.
Object Type: Article
System: The UNT Digital Library
Exactly conservative integrators (open access)

Exactly conservative integrators

Traditional numerical discretizations of conservative systems generically yield an artificial secular drift of any nonlinear invariants. In this work we present an explicit nontraditional algorithm that exactly conserves invariants. We illustrate the general method by applying it to the Three-Wave truncation of the Euler equations, the Volterra-Lotka predator-prey model, and the Kepler problem. We discuss our method in the context of symplectic (phase space conserving) integration methods as well as nonsymplectic conservative methods. We comment on the application of our method to general conservative systems.
Date: July 19, 1995
Creator: Shadwick, B. A.; Bowman, J. C. & Morrison, P. J.
Object Type: Report
System: The UNT Digital Library
Sorption Energy Maps of Clay Mineral Surfaces (open access)

Sorption Energy Maps of Clay Mineral Surfaces

A molecular-level understanding of mineral-water interactions is critical for the evaluation and prediction of the sorption properties of clay minerals that may be used in various chemical and radioactive waste disposal methods. Molecular models of metal sorption incorporate empirical energy force fields, based on molecular orbital calculations and spectroscopic data, that account for Coulombic, van der Waals attractive, and short-range repulsive energies. The summation of the non-bonded energy terms at equally-spaced grid points surrounding a mineral substrate provides a three dimensional potential energy grid. The energy map can be used to determine the optimal sorption sites of metal ions on the exposed surfaces of the mineral. By using this approach, we have evaluated the crystallographic and compositional control of metal sorption on the surfaces of kaolinite and illite. Estimates of the relative sorption energy and most stable sorption sites are derived based on a rigid ion approximation.
Date: July 19, 1999
Creator: Cygan, Randall T. & Kirkpatrick, R. James
Object Type: Article
System: The UNT Digital Library