Miniature Chemical Sensor Combining Molecular Recognition with Evanescent Wave Cavity Ring-Down Spectroscopy (open access)

Miniature Chemical Sensor Combining Molecular Recognition with Evanescent Wave Cavity Ring-Down Spectroscopy

A new chemical detection technology has been realized through EMSP Projects 60231 and 73844 that addresses DOE environmental management needs. The new technology is based on a variant of the sensitive optical absorption technique, cavity ringdown spectroscopy (CRDS). Termed evanescent-wave cavity ring-down spectroscopy (EW-CRDS), the technology employs a miniature solid-state optical resonator having an extremely high Q-factor as the sensing element, where the high-Q is achieved by using ultra-low-attenuation optical materials, ultra-smooth surfaces, and ultra-high reflectivity coatings, as well as low-diffraction-loss designs. At least one total-internal reflection (TIR) mirror is integral to the resonator permitting the concomitant evanescent wave to probe the ambient environment. Several prototypes have been designed, fabricated, characterized, and applied to chemical detection. Moreover, extensions of the sensing concept have been explored to enhance selectivity, sensitivity, and range of application. Operating primarily in the visible and near IR regions, the technology inherently enables remote detection by optical fiber. Producing 11 archival publications, 4 conference proceedings, 5 patents, 19 invited talks, a CRADA, and a patent-license agreement, Projects 60231 and 73844 realized a new chemical detection technology providing >100 times more sensitivity than comparable technologies, while also providing practical advantages.
Date: December 31, 2004
Creator: Pipino, Andrew C. R. & Meuse, Curt W.
Object Type: Report
System: The UNT Digital Library
Nitrogen Control in Electric Arc Furnace Steelmaking by DRI (TRP 0009) (open access)

Nitrogen Control in Electric Arc Furnace Steelmaking by DRI (TRP 0009)

Nitrogen is difficult to remove in electric arc furnace (EAF) steelmaking, requiring the use of more energy in the oxygen steelmaking route to produce low-nitrogen steel. The objective of this work was to determine if the injection of directly reduced iron (DRI) fines into EAFs could reduce the nitrogen content by creating fine carbon monoxide bubbles that rinse nitrogen from the steel. The proposed work included physical and chemical characterization of DRI fines, pilot-scale injection into steel, and mathematical modeling to aid in scale-up of the process. Unfortunately, the pilot-scale injections were unsuccessful, but some full-scale data was obtained. Therefore, the original objectives were met, and presented in the form of recommendations to EAF steelmakers regarding: (1) The best composition and size of DRI fines to use; (2) The amount of DRI fines required to achieve a specific reduction in nitrogen content in the steel; and (3) The injection conditions. This information may be used by steelmakers in techno-economic assessments of the cost of reducing nitrogen with this technology.
Date: March 31, 2004
Creator: Irons, Gordon A.
Object Type: Report
System: The UNT Digital Library
Palladium/Copper Alloy Composite Membranes for High Temperature Hydrogen Separation Progress Report (open access)

Palladium/Copper Alloy Composite Membranes for High Temperature Hydrogen Separation Progress Report

This report summarizes progress made during the first year of research funding from DOE Grant No. DE-FG26-03NT41792 at the Colorado School of Mines. The period of performance was September 1, 2003 through August of 2004. Composite membranes, consisting of a thin Pd alloy film supported on a porous substrate have been investigated as a means of reducing the membrane cost and improving H{sub 2} flux. An electroless plating technique was utilized to deposit subsequent layers of palladium and copper over zirconia and alumina-based microfilters. The composite membranes thus made were annealed and tested at temperatures ranging from 250 to 500 C, under very high feed pressures (up to 450 psig) using pure gases and gaseous mixtures containing H{sub 2}, CO, CO{sub 2}, H{sub 2}O and H{sub 2}S, with the purpose of determining the effects these variables had on the H{sub 2} permeation rate, selectivity and percent recovery. The inhibition caused by CO/CO{sub 2} gases on a 7 {micro}m thick Pd-Cu composite membrane was less than 17% over a wide range of compositions at 350 C. H{sub 2}S caused a strong inhibition of the H{sub 2} flux of the same Pd-Cu composite membrane, which is accentuated at levels of 100 ppm …
Date: August 31, 2004
Creator: Way, J. Douglas
Object Type: Report
System: The UNT Digital Library
Reconstitution and Upgrade of the Thermal Neutron Irradiation Facility in the Basement Medical Room of the MIT Research Reactor (open access)

Reconstitution and Upgrade of the Thermal Neutron Irradiation Facility in the Basement Medical Room of the MIT Research Reactor

The M-011 thermal neutron beam has been reconstituted and upgraded to provide a high intensity and high quality facility for preclinical and certain clinical studies. Intensities of thermal neutrons in the beam range from 5.0-8.5 x 109 n cm-2 s-1. Beam contamination is at a low level where it has no practical influence on beam performance. New computer controlled dose and beam monitoring systems have been implemented which assure precise dose delivery and redundant safety interlocks. An additional beam shutter and massive shielding in the back of the medical room have been added which significantly reduce room background and now permit staff entry without the necessity for lowering the reactor power. This system is needed for BNCT research by the MIT group as well as other US groups. This need became acute with the closure of the BMRR which previously had the only high quality thermal neutron irradiation facility for BNCT in the USA.
Date: December 31, 2004
Creator: Harling, Otto, K.; Riley, Kent, J. & Binns, Peter J.
Object Type: Report
System: The UNT Digital Library
Environmental Biosciences Program Third Quarter Report (open access)

Environmental Biosciences Program Third Quarter Report

In May 2002, the United States Department of Energy (DOE) signed Assistance Instrument Number DE-FC09-02CH11109 with the Medical University of South Carolina (MUSC) to support the Environmental Biosciences Program (EBP). This funding instrument replaces DOE Assistance Instrument Number DE-FC02-98CH10902. EBP is an integrated, multidisciplinary scientific research program, employing a range of research initiatives to identify, study and resolve environmental health risks. These initiatives are consistent with the MUSC role as a comprehensive state-supported health sciences institution and with the nation's need for new and better approaches to the solution of a complex and expansive array of environment-related health problems. The intrinsic capabilities of a comprehensive health sciences institution enable MUSC to be a national resource for the scientific investigation of environmental health issues. EBPs success as a nationally prominent research program is due, in part, to its ability to task-organize scientific expertise from multiple disciplines in addressing these complex problems Current research projects have focused EBP talent and resources on providing the scientific basis for risk-based standards, risk-based decision making and the accelerated clean-up of widespread environmental hazards. These hazards include trichloroethylene (TCE), polychlorinated biphenyls (PCBs), asbestos and low-dose ionizing radiation. A project is also being conducted in the use …
Date: March 31, 2004
Creator: Mohr, Lawrence C.
Object Type: Text
System: The UNT Digital Library
Impermeable Thin Al2O3 Overlay for TBC Protection From Sulfate and Vanadate Attack in Gas Turbines Quarterly Report (open access)

Impermeable Thin Al2O3 Overlay for TBC Protection From Sulfate and Vanadate Attack in Gas Turbines Quarterly Report

To improve the hot corrosion resistance of YSZ thermal barrier coatings, a 25 {micro}m thick Al{sub 2}O{sub 3} overlay were deposited by HVOF thermal spray, respectively, onto to the surface of YSZ coating. In the next reporting period, we will measure or calculate the residue stress within Al{sub 2}O{sub 3} overlay and YSZ coating to study the mechanism of effect of Al{sub 2}O{sub 3} overlay on spalling of YSZ coating. However, due to the thermal expansion mismatch between YSZ coating and Al{sub 2}O{sub 3} overlay, such surface modification using Al{sub 2}O{sub 3} overlay might deteriorate strain tolerance of the TBC. In the present work, in order to investigate the effect of Al{sub 2}O{sub 3} overlay on residual stress developed in the samples during cooling after hot corrosion at high temperature, Finite Element method (FEM) was employed to determine the detailed stress states in the test specimens after cooling. The results showed that there is no high stress concentration at the interface between the YSZ and the bond coat for TBCs system without Al{sub 2}O{sub 3} overlay. On the other hand, the maximum compressive stress with a value of approximately, -330 MPa occurred within the Al{sub 2}O{sub 3} overlay. The maximum …
Date: March 31, 2004
Creator: Mao, Scott X.
Object Type: Report
System: The UNT Digital Library
Pharmacokinetics of Genetically Engineered Antibody Forms Using Positron Emission Tomography (open access)

Pharmacokinetics of Genetically Engineered Antibody Forms Using Positron Emission Tomography

In the last grant period we have focused on multi-step targeting methodologies (MST), as a method for delivery of high dose to the tumor, with low dose to the bone marrow. We have explored uptake in colorectal, pancreatic and prostate cancer, using an special preparation, developed in collaboration with NeoRex A high tumor/bone marrow ratio is clearly achieved with MST, but with a cost, namely the higher dose to normal kidney. For this reason, we have in particular, (a) looked dosimetry for both tumor and normal organ, and especially renal dosimetry, which appears to be the target organ, for Y-90. (b) In parallel with this we have explored the dosimetry of very high dose rate radionuclides, including Holmium-166. (c) In addition, with NaiKong Cheung, we have developed a new MST construct based on the anti-GD2 targeting 5F11; (d) we have successfully completed development of s-factor tables for mice. In summary, renal dosimetry is dominated by about 4-5% of the injected dose being held long-term in the renal cortex, probably in the proximal tubule, due to the universal uptake of small proteins. This appears to be a function of a biotynlated protein binding of the strept-avidin construct, to HSP70. This cortical …
Date: August 31, 2004
Creator: Steven M. Larson, M.D. Nai-Kong Cheung, M.D., Ph.D.
Object Type: Report
System: The UNT Digital Library
Porous Medium Analysis or Interstitial Liquid Removal from Tank 41 and Tank 3 (open access)

Porous Medium Analysis or Interstitial Liquid Removal from Tank 41 and Tank 3

During Tank 41 interstitial liquid removal in fall 2002 and early 2003, analytical analyses of capillary liquid retention and fluid flow in porous saltcake were performed to guide waste processing under the Low Curie Salt program. Tank drainage was completed in June 2003 with the interstitial level at about 68 in. In late June and early July, flush water was added to dissolve hard salt for later liquid retrieval. Data from these subsequent operations has been used to validate the earlier analytical models and assess model uncertainty. Data comparisons suggest the analytical drain model performs well when empirical data are available to calibrate the model. Subsequent model forecasts can be expected to be reasonably accurate, provided the pumping rate is steady.
Date: March 31, 2004
Creator: FLACH, GREGORY
Object Type: Report
System: The UNT Digital Library
Life-Cycle Cost and Payback Period Analysis for Commercial Unitary Air Conditioners (open access)

Life-Cycle Cost and Payback Period Analysis for Commercial Unitary Air Conditioners

This report describes an analysis of the economic impacts of possible energy efficiency standards for commercial unitary air conditioners and heat pumps on individual customers in terms of two metrics: life-cycle cost (LCC) and payback period (PBP). For each of the two equipment classes considered, the 11.5 EER provides the largest mean LCC savings. The results show how the savings vary among customers facing different electricity prices and other conditions. At 11.5 EER, at least 80% of the users achieve a positive LCC savings. At 12.0 EER, the maximum efficiency analyzed, mean LCC savings are lower but still positive. For the {ge} $65,000 Btu/h to <135,000 Btu/h equipment class, 59% of users achieve a positive LCC savings. For the $135,000 Btu/h to <240,000 Btu/h equipment class, 91% of users achieve a positive LCC savings.
Date: March 31, 2004
Creator: Rosenquist, Greg; Coughlin, Katie; Dale, Larry; McMahon, James & Meyers, Steve
Object Type: Report
System: The UNT Digital Library
Range-wide success of red-cockaded woodpecker translocations. (open access)

Range-wide success of red-cockaded woodpecker translocations.

Edwards, John W.; Costa, Ralph. 2004. Range-wide success of red-cockaded woodpecker translocations. In: Red-cockaded woodpecker; Road to Recovery. Proceedings of the 4th Red-cockaded woodpecker Symposium. Ralph Costa and Susan J. Daniels, eds. Savannah, Georgia. January, 2003. Chapter 6. Translocation. Pp 307-311. Abstract: Red-cockaded woodpeckers (Picoides borealis) have declined range-wide during the past century, suffering from habitat loss and the effects of fire exclusion in older southern pine forests. Red-cockaded woodpecker translocations are a potentially important tool in conservation efforts to reestablish red-cockaded woodpeckers in areas from which they have been extirpated. Currently, translocations are critical in ongoing efforts to save and restore the many existing small populations. We examined the effects of demographic and environmental factors on the range-wide success of translocations between 1989 and 1995.
Date: December 31, 2004
Creator: Edwards, John W. & Costa, Ralph
Object Type: Article
System: The UNT Digital Library
Mechanisms of Heavy Metal Sequestration in Soils: Plant-Microbe Interactions and Organic Matter Aging (open access)

Mechanisms of Heavy Metal Sequestration in Soils: Plant-Microbe Interactions and Organic Matter Aging

For stabilization of heavy metals at contaminated sites, the three way interaction among soil organic matter (OM)-microbes-plants, and their effect on heavy metal binding is critically important for long-term sustainability, a factor that is poorly understood at the molecular level. Using a soil aging system, the humification of plant matter such as wheat straw was probed along with the effect on microbial community on soil from the former McClellan Air Force Base.
Date: December 31, 2004
Creator: Fan, Teresa W.-M.; Higashi, Richard M.; Crowley, David; Cassel, Andrew N. Lane: Teresa A. & Green, Peter G.
Object Type: Report
System: The UNT Digital Library
Tracing Geothermal Fluids (open access)

Tracing Geothermal Fluids

Chemical compounds have been designed under this contract that can be used to trace water that has been injected into vapor-dominated and two-phase geothermal fields. Increased knowledge of the injection flow is provided by the tracers, and this augments the power that can be produced. Details on the stability and use of these tracers are included in this report.
Date: March 31, 2004
Creator: Nash, Michael C. Adams Greg
Object Type: Report
System: The UNT Digital Library
Availability and abundance of prey for the red-cockaded woodpecker. (open access)

Availability and abundance of prey for the red-cockaded woodpecker.

Red-cockaded woodpecker; Road to Recovery. Proceedings of the 4th Red-cockaded woodpecker Symposium. Ralph Costa and Susan J. Daniels, eds. Savannah, Georgia. January, 2003. Chapter 11. Prey, Fire, and Community Ecology. Pp 633-645. Abstract: Over a 10-year period we investigated red-cockaded woodpecker (Picoides borealis) prey use, sources of prey, prey distribution within trees and stands, and how forest management decisions affect prey abundance in South Carolina, Alabama, Georgia and Florida. Cameras were operated at 31 nest cavities to record nest visits with prey in 4 locations that ranged in foraging habitat from pine stands established in old fields to an old-growth stand in South Georgia. Examination of nearly 12,000 photographs recorded over 5 years revealed that, although red-cockaded woodpeckers used over 40 arthropods for food, the majority of the nestling diet is comprised of a relatively small number of common arthropods.
Date: December 31, 2004
Creator: Hanula, James, L. & Horn, Scott.
Object Type: Article
System: The UNT Digital Library
SYNTHESIS AND CHARACTERIZATION OF CO-AND H2S-TOLERANT ELECTROCATALYSTS FOR PEM FUEL CELL (open access)

SYNTHESIS AND CHARACTERIZATION OF CO-AND H2S-TOLERANT ELECTROCATALYSTS FOR PEM FUEL CELL

The present state-of-art Proton Exchange Membrane Fuel Cell (PEMFC) technology is based on platinum (Pt) as a catalyst for both the fuel (anode) and air (cathode) electrodes. This catalyst is highly active but susceptible to poisoning by CO, which may be present in the H{sub 2}-fuel used or may be introduced during the fuel processing. Presence of trace amount of CO and H{sub 2}S in the H{sub 2}-fuel poisons the anode irreversibly and decreases the performance of the PEMFCs. In an effort to reduce the Pt-loading and improve the PEMFC performance, we propose to synthesize a number of Pt-based binary, ternary, and quaternary electrocatalysts using Ru, Mo, Ir, Ni, and Co as a substitute for Pt. By fine-tuning the metal loadings and compositions of candidate electrocatalysts, we plan to minimize the cost and optimize the catalyst activity and performance in PEMFC. The feasibility of the novel electrocatalysts will be demonstrated in the proposed effort with gas phase CO and H{sub 2}S concentrations typical of those found in reformed fuel gas with coal/natural gas/methanol feedstocks. During this reporting period several bi-metallic electrocatalysts were synthesized and tested in MEAs. From Galvonstatic study the catalytic activity was found in the order of: Pt/Ru/C …
Date: March 31, 2004
Creator: Ilias, Shamsuddin
Object Type: Report
System: The UNT Digital Library
A Pseudo-Random Number Generator Based on Normal Numbers (open access)

A Pseudo-Random Number Generator Based on Normal Numbers

In a recent paper, Richard Crandall and the present author established that each of a certain class of explicitly given real constants, uncountably infinite in number, is b-normal, for an integer that appears in the formula defining the constant. A b-normal constant is one where every string of m digits appears in the base-b expansion of the constant with limiting frequency b{sup -m}. This paper shows how this result can be used to fashion an efficient and effective pseudo-random number generator, which generates successive strings of binary digits from one of the constants in this class. The resulting generator, which tests slightly faster than a conventional linear congruential generator, avoids difficulties with large power-of-two data access strides that may occur when using conventional generators. It is also well suited for parallel processing--each processor can quickly and independently compute its starting value, with the collective sequence generated by all processors being the same as that generated by a single processor.
Date: December 31, 2004
Creator: Bailey, David H.
Object Type: Report
System: The UNT Digital Library
DOWNHOLE VIBRATION MONITORING & CONTROL SYSTEM (open access)

DOWNHOLE VIBRATION MONITORING & CONTROL SYSTEM

The deep hard rock drilling environment induces severe vibrations into the drillstring, which can cause reduced rates of penetration (ROP) and premature failure of the equipment. The only current means of controlling vibration under varying conditions is to change either the rotary speed or the weight-on-bit (WOB). These changes often reduce drilling efficiency. Conventional shock subs are useful in some situations, but often exacerbate the problems. The objective of this project is development of a unique system to monitor and control drilling vibrations in a ''smart'' drilling system. This system has two primary elements: (1) The first is an active vibration damper (AVD) to minimize harmful axial, lateral and torsional vibrations. The hardness of this damper will be continuously adjusted using a robust, fast-acting and reliable unique technology. (2) The second is a real-time system to monitor drillstring vibration, and related parameters. This monitor adjusts the damper according to local conditions. In some configurations, it may also send diagnostic information to the surface via real-time telemetry. The AVD is implemented in a configuration using magnetorheological (MR) fluid. By applying a current to the magnetic coils in the damper, the viscosity of the fluid can be changed rapidly, thereby altering the …
Date: August 31, 2004
Creator: Cobern, Martin E.
Object Type: Report
System: The UNT Digital Library
Development of On-line Instrumentation and Techniques to Detect and Measure Particulates Quarterly Report (open access)

Development of On-line Instrumentation and Techniques to Detect and Measure Particulates Quarterly Report

In this quarter, we have constructed the first field deployable PM measurement system. This system is retrofit from the system that we designed and tested in the lab, and by adding light blocking covers and rugged electronic boxes, we are now ready to test the instrument in our industrial collaborator's site with real engines. We have also collected tons of data on standard PM particles with our lab instrument.
Date: July 31, 2004
Creator: Wu, Sheng; Palm, Steve; Tang, Yongchun & Goddard, William A., III
Object Type: Report
System: The UNT Digital Library
A NEW APPROACH TO RADIONUCLIDE ANALYSIS IN GROUNDWATERS (open access)

A NEW APPROACH TO RADIONUCLIDE ANALYSIS IN GROUNDWATERS

A method using liquid scintillation spectral analysis (LSSA) for analyzing mixtures of radionuclides in groundwater samples, which is fast, simple, and inexpensive, was developed and bench-tested. Samples can be measured in a field laboratory with a new commercial portable liquid scintillation instrument that provides advanced analysis, display, and computational features previously found only in large expensive laboratory models. Results can be available within hours from the time samples are collected. The analysis provides a good measure of total sample activity and a spectral index value that may detect changes in radionuclide distributions from previous analyses when counting statistic are adequate. If a sample shows no change, further analytical costs for it may be avoided. A method that rapidly and quantitatively concentrates very low levels of activity from liter-size samples in minutes was also tested. With some modest improvements in this step, this work offers a completely new methodology and approach to groundwater remediation, which can dramatically reduce analytical costs and speed monitored cleanup and closure in many types of radiological work programs.
Date: August 31, 2004
Creator: HOCHEL, ROBERTC.
Object Type: Article
System: The UNT Digital Library
Evaluation of the TiO2 Limit for DWPF Glass (open access)

Evaluation of the TiO2 Limit for DWPF Glass

The titanium dioxide (TiO2) solubility limit for Defense Waste Processing Facility (DWPF) glasses evaluated in this report. Based on the analyses of existing data, the solubility limit can be raised from 1 wt percent to 2 wt percent. This work has been prepared to address technical issues discussed in Technical Task Request SPTTR-2003-00004 (Lilliston, 2003) and in accordance with the Task Technical and Quality Assurance Plan (Lorier, 2003).
Date: March 31, 2004
Creator: LORIER, TROY
Object Type: Report
System: The UNT Digital Library
Vortices, Reconnection and Turbulence in High Electron-Beta Plasmas (open access)

Vortices, Reconnection and Turbulence in High Electron-Beta Plasmas

Plasmas in which the kinetic energy exceeds the magnetic energy by a significant factor are common in space and in the laboratory. Such plasmas can convect magnetic fields and create null points in whose vicinity first the ions become unmagnetized, then the electrons. This project focuses on the detailed study of the transition regime of these plasmas.
Date: August 31, 2004
Creator: Stenzel, R. L.
Object Type: Report
System: The UNT Digital Library
Development of a 400 Level 3C Clamped Downhole Seismic Receiver Array for 3D Borehole Seismic Imaging of Gas Reservoirs, Quarterly Report: January 1 - March 31, 2004 (open access)

Development of a 400 Level 3C Clamped Downhole Seismic Receiver Array for 3D Borehole Seismic Imaging of Gas Reservoirs, Quarterly Report: January 1 - March 31, 2004

Borehole seismology is the highest resolution geophysical imaging technique available today to the oil and gas industry for characterization and monitoring of oil and gas reservoirs. However, the industry's ability to economically do high resolution 3D imaging of deep and complex gas reservoirs using borehole seismology is currently frustrated by the lack of the acquisition technology necessary to record the large volumes of the high frequency, high signal-to-noise-ratio borehole seismic data needed to do 3D imaging. This project takes direct aim at this shortcoming by developing a 400 level 3C clamped downhole seismic receiver array, and accompanying software, for borehole seismic 3D imaging. This large borehole seismic array will remove the technical acquisition barrier for recording the necessary volumes of data to do high resolution 3D VSP or 3D cross well seismic imaging. 3D VSP and long range Cross-Well Seismology (CWS) are two of the borehole seismic techniques that will allow the Gas industry to take the next step in their quest for higher resolution images of the gas reservoirs for the purpose of improving the recovery of the natural gas resources. Today only a fraction of the original Oil or Gas in place is produced when reservoirs are considered …
Date: May 31, 2004
Creator: Paulsson, Bjorn N. P.
Object Type: Report
System: The UNT Digital Library
Monitoring interactions between red-cockaded woodpeckers and southern flying squirrels. (open access)

Monitoring interactions between red-cockaded woodpeckers and southern flying squirrels.

Risch, Thomas S., and Susan C. Loeb. 2004. Monitoring interactions between red-cockaded woodpeckers and southern flying squirrels. In: Red-cockaded woodpecker; Road to Recovery. Proceedings of the 4th Red-cockaded woodpecker Symposium. Ralph Costa and Susan J. Daniels, eds. Savannah, Georgia. January, 2003. Chapter 8. Cavities, Cavity Trees, and Cavity Communities. Pp 504-505. Abstract: Although several studies have suggested that southern flying squirrels (Glaucomys volans) may have a significant negative impact on red-cockades woodpeckers (Picoides borealsi) (Loeb and Hooper 1997, Laves and Loeb 1999), the nature of the interactions between the species remains unclear. Particularly lacking are data that address if southern flying squirrels directly usurp red-cockaded woodpecker s from cavities, or simply occupy cavities previously abandoned by red-cockaded woodpeckers. Ridley et al. (1997) observed the displacement of a red-cockaded woodpecker by a southern flying squirrel that was released after being captured. Observations of nocturnal displacements of red-cockaded woodpeckers by flying squirrels, however, are lacking. Due to the difficulty of observing interspecific interactions, determining the mechanisims by which flying squirrels impact red-cockaded woodpeckers is problematic.
Date: December 31, 2004
Creator: Risch, Thomas S. & Loeb, Susan C.
Object Type: Article
System: The UNT Digital Library
Cupola Furnace Computer Process Model (open access)

Cupola Furnace Computer Process Model

The cupola furnace generates more than 50% of the liquid iron used to produce the 9+ million tons of castings annually. The cupola converts iron and steel into cast iron. The main advantages of the cupola furnace are lower energy costs than those of competing furnaces (electric) and the ability to melt less expensive metallic scrap than the competing furnaces. However the chemical and physical processes that take place in the cupola furnace are highly complex making it difficult to operate the furnace in optimal fashion. The results are low energy efficiency and poor recovery of important and expensive alloy elements due to oxidation. Between 1990 and 2004 under the auspices of the Department of Energy, the American Foundry Society and General Motors Corp. a computer simulation of the cupola furnace was developed that accurately describes the complex behavior of the furnace. When provided with the furnace input conditions the model provides accurate values of the output conditions in a matter of seconds. It also provides key diagnostics. Using clues from the diagnostics a trained specialist can infer changes in the operation that will move the system toward higher efficiency. Repeating the process in an iterative fashion leads to near …
Date: December 31, 2004
Creator: Katz, S.
Object Type: Report
System: The UNT Digital Library
Novel Fission-Product Separation based on Room-Temperature Ionic Liquids (open access)

Novel Fission-Product Separation based on Room-Temperature Ionic Liquids

U.S. DOE's underground storage tanks at Hanford, SRS, and INEEL contain liquid wastes with high concentrations of radioactive cesium-137 and strontium-90. Because the primary chemical components of alkaline supernatants are sodium nitrate and sodium hydroxide, the majority of this could be disposed of as low level waste if radioactive cesium-137 and strontium- 90 could be selectively removed. The underlying goal of this project was to investigate the application of ionic liquids as novel solvents for new solvent extraction processes for separation of cesium-137 and strontium-90 from tank wastes. Ionic liquids are a distinct sub-set of liquids, comprising only of cations and anions they are proving to be increasingly interesting fluids for application in systems from electrochemistry to energetic materials, and are also rapidly establishing their promise as viable media for synthesis and separations operations. Properties including low melting points, electrochemical conductivity, wide liquid ranges, lack of vapor-pressure, and chemical tunability have encouraged researchers to explore the uses of ILs in place of volatile organic solvents. The most promising current developments arise from control of the unique combinations of chemical and physical properties characteristic of ionic liquids.
Date: December 31, 2004
Creator: Rogers, Robin D.
Object Type: Report
System: The UNT Digital Library