Application of a World Wide Web technology to environmental remediation (open access)

Application of a World Wide Web technology to environmental remediation

As part of the Formerly Utilized Site Remedial Action Program (FUSRAP), the United States Army Corps of Engineers (USACE), Buffalo District, is responsible for overseeing the remediation of several sites within its jurisdiction. FUSRAP sites are largely privately held facilities that were contaminated by activities associated with the nuclear weapons program in the 1940s, 50s, and 60s. The presence of soils and structures contaminated with low levels of radionuclides is a common problem at these sites. Typically, contaminated materials must be disposed of off-site at considerable expense (up to several hundred dollars per cubic yard of waste material). FUSRAP is on an aggressive schedule, with most sites scheduled for close-out in the next couple of years. Among the multitude of tasks involved in a typical remediation project is the need to inform and coordinate with active stakeholder communities, including local, state, and federal regulators.
Date: March 9, 2000
Creator: Johnson, R. & Durham, L. A.
System: The UNT Digital Library
Automating the management of environmental compliance reporting: Making the complex simple (open access)

Automating the management of environmental compliance reporting: Making the complex simple

Environmental compliance reporting requirements are notoriously complex. This reporting complexity is compounded by organizational and functional complexity at Rocky Mountain Arsenal (RMA), where the Department of the Army has undertaken a multi billion dollar environmental cleanup action. This site is subject to both fixed and contingent federal, state, and local reporting requirements. Management and operation of the site is characterized by numerous organizational layers, and compliance information is generated by many different contractors and subcontractors. This information must be compiled by various managers and reported to either regulators or Department of the Army offices. The RMA Environmental Compliance Office and top-level management must be assured that these reports are being promptly generated and submitted. With over 1,500 individual reporting requirements forecasted for over the next 11 years, the managerial challenge is immense. To facilitate the collation of data and issuance of compliance reports, an intranet-based database is being developed. This database is designed to be available to all personnel with access to the site's environmental compliance intranet. It presents all applicable reporting requirements in an easily sortable format. Information available for each report includes deadlines, report status, recipients, individuals responsible for report generation, and other relevant data fields. Reports can …
Date: March 9, 2000
Creator: Perkins, S.
System: The UNT Digital Library
Degradation of EBR-II driver fuel during wet storage (open access)

Degradation of EBR-II driver fuel during wet storage

Characterization data are reported for sodium bonded EBR-II reactor fuel which had been stored underwater in containers since the 1981--1982 timeframe. Ten stainless steel storage containers, which had leaked water during storage due to improper sealing, were retrieved from the ICPP-603 storage basin at the Idaho National Engineering and Environmental Laboratory (INEEL) in Idaho. In the container chosen for detailed destructive analysis, the stainless steel cladding on the uranium alloy fuel had ruptured and fuel oxide sludge filled the bottom of the container. Headspace gas sampling determined that greater than 99% hydrogen was present. Cesium 137, which had leached out of the fuel during the aqueous corrosion process, dominated the radionuclide source term of the water. The metallic sodium from the fuel element bond had reacted with the water, forming a concentrated caustic solution of NaOH.
Date: March 9, 2000
Creator: Pahl, R. G.
System: The UNT Digital Library
Development of a coupled dynamics code with transport theory capability and application to accelerator driven systems transients (open access)

Development of a coupled dynamics code with transport theory capability and application to accelerator driven systems transients

The VARIANT-K and DIF3D-K nodal spatial kinetics computer codes have been coupled to the SAS4A and SASSYS-1 liquid metal reactor accident and systems analysis codes. SAS4A and SASSYS-1 have been extended with the addition of heavy liquid metal (Pb and Pb-Bi) thermophysical properties, heat transfer correlations, and fluid dynamics correlations. The coupling methodology and heavy liquid metal modeling additions are described. The new computer code suite has been applied to analysis of neutron source and thermal-hydraulics transients in a model of an accelerator-driven minor actinide burner design proposed in an OECD/NEA/NSC benchmark specification. Modeling assumptions and input data generation procedures are described. Results of transient analyses are reported, with emphasis on comparison of P1 and P3 variational nodal transport theory results with nodal diffusion theory results, and on significance of spatial kinetics effects.
Date: March 9, 2000
Creator: Cahalan, J. E.; Ama, T.; Palmiotti, G.; Taiwo, T. A. & Yang, W. S.
System: The UNT Digital Library
The Monoclinic Phase in PZT: New Light on Morphotropic Phase Boundaries (open access)

The Monoclinic Phase in PZT: New Light on Morphotropic Phase Boundaries

A summary of the work recently carried out on the morphotropic phase boundary (MPB) of PZT is presented. By means of x-ray powder diffraction on ceramic samples of excellent quality, the MPB has been successfully characterized by changing temperature in a series of closely spaced compositions. As a result, an unexpected monoclinic phase has been found to exist in between the well-known tetragonal and rhombohedral PZT phases. A detailed structural analysis, together with the investigation of the field effect in this region of compositions, have led to an important advance in understanding the mechanisms responsible for the physical properties of PZT as well as other piezoelectric materials with similar morphotropic phase boundaries.
Date: March 9, 2000
Creator: Noheda, B.; Gonzalo, J. A.; Guo, R.; Park, S. E.; Cross, L. E.; Cox, D. E. et al.
System: The UNT Digital Library
Monolithic GaAs surface acoustic wave chemical microsensor array (open access)

Monolithic GaAs surface acoustic wave chemical microsensor array

A four-channel surface acoustic wave (SAW) chemical sensor array with associated RF electronics is monolithically integrated onto one GaAs IC. The sensor operates at 690 MHz from an on-chip SAW based oscillator and provides simple DC voltage outputs by using integrated phase detectors. This sensor array represents a significant advance in microsensor technology offering miniaturization, increased chemical selectivity, simplified system assembly, improved sensitivity, and inherent temperature compensation.
Date: March 9, 2000
Creator: Hietala, Vincent M.; Casalnuovo, Stephen A.; Heller, Edwin J.; Wendt, Joel R.; Frye-Mason, Gregory Charles & Baca, Albert G.
System: The UNT Digital Library
New 500-kV Ion Source Test Strand for HIF (open access)

New 500-kV Ion Source Test Strand for HIF

One of the most challenging aspects of ion beam driven inertial fusion energy is the reliable and efficient generation of low emittance, high current ion beams. The primary ion source requirements include a rise time of order 1-{micro}sec, a pulse width of at least 20-{micro}sec, a flattop ripple of less than 0.1% and a repetition rate of at least 5-HZ. Naturally, at such a repetition rate, the duty cycle of the source must be greater than 10{sup 8} pulses. Although these specifications do not appear to exceed the state-of-the-art for pulsed power, considerable effort remains to develop a suitable high current ion source. Therefore, we are constructing a 500-kV test stand specifically for studying various ion source concepts including surface, plasma and metal vapor arc. This paper will describe the test stand design specifications as well as the details of the various subsystems and components.
Date: March 9, 2000
Creator: Sangster, T. C.; Ahle, L. E.; Halaxa, E. F.; Karpenko, V. P.; Oldaker, M. E.; Mitchell, J. W. et al.
System: The UNT Digital Library
Opto-acoustic cell permeation (open access)

Opto-acoustic cell permeation

Optically generated acoustic waves have been used to temporarily permeate biological cells. This technique may be useful for enhancing transfection of DNA into cells or enhancing the absorption of locally delivered drugs. A diode-pumped frequency-doubled Nd:YAG laser operating at kHz repetition rates was used to produce a series of acoustic pulses. An acoustic wave was formed via thermoelastic expansion by depositing laser radiation into an absorbing dye. Generated pressures were measured with a PVDF hydrophone. The acoustic waves were transmitted to cultured and plated cells. The cell media contained a selection of normally- impermeable fluorescent-labeled dextran dyes. Following treatment with the opto-acoustic technique, cellular incorporation of dyes, up to 40,000 Molecular Weight, was noted. Control cells that did not receive opto-acoustic treatment had unremarkable dye incorporation. Uptake of dye was quantified via fluorescent microscopic analysis. Trypan Blue membrane exclusion assays and fluorescent labeling assays confirmed the vitality of cells following treatment. This method of enhanced drug delivery has the potential to dramatically reduce required drug dosages and associated side effects and enable revolutionary therapies.
Date: March 9, 2000
Creator: Visuri, S R & Heredia, N
System: The UNT Digital Library
Pulse radiolysis studies in supercritical CO{sub 2} (open access)

Pulse radiolysis studies in supercritical CO{sub 2}

The pulse radiolysis technique has been applied to study reactions of ions in supercritical solutions. Evidence for the formation of C{sub 2}O{sub 4}{sup +} has been found in supercritical CO{sub 2}. The rate of the electron transfer reaction from dimethyl aniline to the C{sub 2}O{sub 4}{sup +} was measured over the density range of 0.17--0.7 g/cm{sup 3}. The reaction rate was measured to be close to diffusion-controlled at the lowest density; at higher densities, the rate was considerably below the apparent diffusion-controlled rate. Similar behavior was found for the reaction of the anion (presumably C{sub 2}O{sub 4}{sup {minus}}) with benzoquinone. The reaction of O{sub 2} with C{sub 2}O{sub 4}{sup +} was considerably slower than the expected diffusion-controlled rate.
Date: March 9, 2000
Creator: Jonah, C. D.; Dimitrijevic, N. M.; Bartels, D. M. & Takahashi, K.
System: The UNT Digital Library
Soft Mode Anomalies in the Perovskite Relaxor Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3} (open access)

Soft Mode Anomalies in the Perovskite Relaxor Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}

Neutron inelastic scattering measurements of the polar TO phonon mode in the cubic relaxor Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}, at room temperature, reveal anomalous behavior similar to that recently observed in Pb(Zn{sub 1/3}Nb{sub 2/3}){sub 0.92}Ti{sub 0.08}O{sub 3} in which the optic branch appears to drop precipitously into the acoustic branch at a finite value of the momentum transfer q = 0.2 {angstrom}{sub {minus}1}, measured from the zone center. By contrast, a recent neutron study indicates that PMN exhibits a normal TO phonon dispersion at 800 K. The authors speculate this behavior is common to all relaxor materials, and is the result of the presence of nanometer-scale polarized domains in the crystal that form below a temperature T{sub d}, which effectively prevent the propagation of long wavelength (q = 0) phonons.
Date: March 9, 2000
Creator: Gehring, P. M.; Vakrushev, S. B. & Shirane, G.
System: The UNT Digital Library
The solvated electron in supercritical water (open access)

The solvated electron in supercritical water

In order to investigate the feasibility for high-efficiency supercritical-water-cooled nuclear reactors, a study of radiation chemistry in supercritical water has been undertaken. Preliminary results in measurement of the optical absorption of the hydrated electron are reported, and compared with recent anion cluster data.
Date: March 9, 2000
Creator: Bartels, D. M.; Takahashi, K.; Cline, J. & Jonah, C. D.
System: The UNT Digital Library
Solvated electrons formed in methanol cluster in ethane (open access)

Solvated electrons formed in methanol cluster in ethane

The authors have studied the spectral shift of the solvated electron in MeOH/C{sub 2}H{sub 6} mixture using pulse radiolysis. The solvated electrons were formed by ionizing the solution. The spectral shift can be explained in terms of MeOH cluster size formed in the solution. With increasing temperature at constant mole fraction of MeOH, the spectral maximum shifts toward low energy. The width at red side increased with increasing temperature, however, there is no significant changes in the blue side of the spectra with temperature.
Date: March 9, 2000
Creator: Takahashi, K.; Bartels, D. M.; Jonah, C. D. & Dimitrijevic, N. A.
System: The UNT Digital Library
Visualization of micro-scale phase displacement processes in retention and outflow experiments: Non-uniqueness of unsaturated flow properties (open access)

Visualization of micro-scale phase displacement processes in retention and outflow experiments: Non-uniqueness of unsaturated flow properties

Methods to determine unsaturated hydraulic properties can exhibit random and non-unique behavior. The authors assess the causes for these behaviors by visualizing micro-scale phase displacement processes during equilibrium retention and transient outflow experiments. They observe that the drainage process is composed of a fast fingering followed by a slower backfilling. The influence of each these processes is controlled by the size and the speed of the applied boundary step, the initial saturation and its structure and by small-scale heterogeneities. Because the mixture of these micro-scale processes yields macro-scale effective behavior, measured unsaturated flow properties are also a function of these controls. These results suggest limitations on the current definitions and uniqueness of unsaturated hydraulic properties.
Date: March 9, 2000
Creator: MORTENSEN,ANNETTE P.; GLASS JR.,ROBERT J.; HOLLENBECK,KARL & JENSEN,KARSTEN H.
System: The UNT Digital Library
18th IAEA Fusion Energy Conference Summary of Technology and Power Plans (open access)

18th IAEA Fusion Energy Conference Summary of Technology and Power Plans

There were 90 papers presented at the Conference in the category of Technology and Power Plants accounting for about 25% of the total number of contributions. As was the case at the previous meeting, a large number of papers dealt with the ITER-Engineering Design Activity (EDA) and ITER technology R&D. In the author's opinion, the rapid progress made during the ITER EDA extension on the completion of the new ITER-FEAT design and its physics and technology R&D validation stands out as the highlight of the meeting. Steady progress is being made on several other technology fronts as well. The results point towards emerging research trends in the following areas: steady-state operation with advanced performance and the increasingly important role of enabling technologies in achieving this goal, advanced, high-performance, environmentally attractive materials for the fusion energy goal, reactor and near-term applications studies that exploit advances both in the physics and technology fronts for lower cost of electricity and improved safety and environmental features, and socioeconomic studies that are helping to promote the attractive features of fusion and its public acceptance. The remaining sections of this paper are organized along the lines of these major themes; namely, ITER EDA Design, ITER Technology …
Date: March 9, 2001
Creator: Milora, S. L.
System: The UNT Digital Library
Analysis of Americium in Transplutonium Process Solutions (open access)

Analysis of Americium in Transplutonium Process Solutions

One of the more difficult analyses in the transplutonium field is the determination of americium at trace levels in a complex matrix such as a process dissolver solution. Because of these conditions a highly selective separation must precede the measurement of americium. The separation technique should be mechanically simple to permit remote operation with master-slave manipulators. For subsequent americium measurement by the mass spectroscopic isotopic-dilution technique, plutonium and curium interferences must also have been removed.
Date: March 9, 2001
Creator: Ferguson, R.B.
System: The UNT Digital Library
Composition-structure-property-performance relationship inMn-substituted LiMn2O4 (open access)

Composition-structure-property-performance relationship inMn-substituted LiMn2O4

The spinel LiMn{sub 2}O{sub 4} has been extensively studied as a positive electrode active material in lithium rechargeable batteries. Partial substitution of Mn by another metal has also been the subject of recent study in an effort to improve the cycling performance. In general, the literature has shown that Mn substitution results in improved cycling stability at the expense of capacity (1,2). Resistance to the formation of tetragonal phase upon lithiation of the starting spinel (via a higher nominal Mn oxidation state in the substituted spinel) has been suggested as a mechanism for the improved performance. The degree of substitution is an important factor to optimize in order to minimize capacity loss and costs. The spectroscopic investigations on LiMn{sub 2}O{sub 4} described in the previous paper (LixMn2O4) confirmed that the cooperative Jahn-Teller effect (CJTE) from the [Mn{sup 3+}O{sub 6}] octahedra is the mechanism for the cubic to tetragonal phase transformation. The driving force for the CJTE is based upon the electronic structure, therefore changes in electronic structure should lead to changes in the phase behavior. The fact that the LiMn{sub 1.5}Ni{sub 0.5}O{sub 4} does not form tetragonal phase upon discharging (FUJI3, MUCK?), unlike the 100% Mn{sup 4+} spinel Li{sub 4}Mn{sub …
Date: March 9, 2001
Creator: Horne, Craig R.; Richardson, Thomas J.; Gee, B.; Tucker, Mike; Grush, Melissa M.; Bergmann, Uwe et al.
System: The UNT Digital Library
Evaluation of Creep Property of AS800 Silicon Nitride from As-Processed Surface Regions (open access)

Evaluation of Creep Property of AS800 Silicon Nitride from As-Processed Surface Regions

Tensile creep studies were carried out to evaluate the creep performance of AS800 silicon nitride samples extracted from the surface and bulk regions of as-processed billets at 1350 C in air. The objective of this study was to understand the creep properties of the silicon nitride in the as-processed surface region and determine if they are comparable to those obtained from the bulk region. The results indicated that samples from the as-processed surface region exhibited higher creep rates and shorter lifetimes as compared with those obtained from the bulk region. The poor creep performance of material from the as-processed surface region was due to the higher content of glassy phase enriched with oxygen and sintering additive elements.
Date: March 9, 2001
Creator: Lin, H. T.
System: The UNT Digital Library
Mobile Measurement of an Atmospheric Tracer (open access)

Mobile Measurement of an Atmospheric Tracer

This paper describes a mobile analyzer for sulfur hexafluoride, an atmospheric tracer. A commercial instrument is used on-board a moving vehicle to measure tracer concentrations in the parts per trillion (ppt) range. This instrument provides rapid, in-the-field data at minimum cost.
Date: March 9, 2001
Creator: Milham, R. C.
System: The UNT Digital Library
Regulatory Aspects of Borosilicate Glass High-Level Waste Forms the Process, the Product and the Disposal (open access)

Regulatory Aspects of Borosilicate Glass High-Level Waste Forms the Process, the Product and the Disposal

Immobilization of high-level radioactive waste (HLW) in borosilicate glass is acknowledged world-wide as an acceptable method for preparing HLW for geologic disposal. A waste acceptance process is underway in the United States that will provide specifications and procedures for waste producers well in advance of the availability of a federal repository. Extensive experimental data and rigorous quality assurance and control for plant operation are expected to provide convincing evidence that borosilicate glass waste forms produced in the vitrification plants meet the specifications and can be disposed of safely in a geologic repository.
Date: March 9, 2001
Creator: Hennelly, E.J.
System: The UNT Digital Library
Some Nonlinear Reconstruction Algorithms for Electrical Impedance Tomography (open access)

Some Nonlinear Reconstruction Algorithms for Electrical Impedance Tomography

An impedance camera [Henderson and Webster, 1978; Dines and Lytle, 1981]--or what is now more commonly called electrical impedance tomography--attempts to image the electrical impedance (or just the conductivity) distribution inside a body using electrical measurements on its boundary. The method has been used successfully in both biomedical [Brown, 1983; Barber and Brown, 1986; J. C. Newell, D. G. Gisser, and D. Isaacson, 1988; Webster, 1990] and geophysical applications [Wexler, Fry, and Neurnan, 1985; Daily, Lin, and Buscheck, 1987], but the analysis of optimal reconstruction algorithms is still progressing [Murai and Kagawa, 1985; Wexler, Fry, and Neurnan, 1985; Kohn and Vogelius, 1987; Yorkey and Webster, 1987; Yorkey, Webster, and Tompkins, 1987; Berryman and Kohn, 1990; Kohn and McKenney, 1990; Santosa and Vogelius, 1990; Yorkey, 1990]. The most common application is monitoring the influx or efflux of a highly conducting fluid (such as brine in a porous rock or blood in the human body) through the volume being imaged. For biomedical applications, this met hod does not have the resolution of radiological methods, but it is comparatively safe and inexpensive and therefore provides a valuable alternative when continuous monitoring of a patient or process is desired. The following discussion is intended …
Date: March 9, 2001
Creator: Berger, E. L.
System: The UNT Digital Library
Treatment of Water in Nuclear Fuel Storage Basins to Control Radioactivity Release (open access)

Treatment of Water in Nuclear Fuel Storage Basins to Control Radioactivity Release

Visibility and radioactivity control in the fuel component storage and disassembly basins at the Savannah River Plant are maintained with a newly developed purification system. Experimental work was performed to develop the application of sand filters to operate at high flow rates with an effluent turbidity below 0.1 JTU squared. Filtration efficiency of SRP sand filters is dependent on the characteristics of the solids in the feed water and the degree to which filterability can be improved by addition of coagulant aids. It is independent of flow up to flow rates of 15 gpm/square feet (higher flow rates have not been tested). Effluent turbidity remains below 0.1 JTU with no indication of breakthrough. Total water throughput is dependent on the amount of solids removed and is independent of flow rate and concentration of solids.
Date: March 9, 2001
Creator: Bertsche, E.C.
System: The UNT Digital Library
Tritium Separation Using Metal Hydrides (open access)

Tritium Separation Using Metal Hydrides

This paper discusses some of the metal hydride and intermetallic compounds which readily absorb the hydrogen gas by a simple contact to form metal hydrides. Metal hydrides have several important properties for the hydrogen isotope separation.
Date: March 9, 2001
Creator: Lee, M.W.
System: The UNT Digital Library
The Effects of Radiation Induced Carbon Contamination on the Performance of an EUV Lithographic Optic (open access)

The Effects of Radiation Induced Carbon Contamination on the Performance of an EUV Lithographic Optic

Carbon deposition in EUVL is known to occur when optical surfaces in a hydrocarbon environment are exposed to EUV light. Carbon contamination on EUV optical elements affects both the absorption and phase of the reflected light. Because the carbon deposition alters the phase structure of the reflected EUV light it effectively alters the figure of these optics and, thus, the aberrations as well. Absorption by deposited carbon not only reduces throughput but also leads to apodisation of the pupil, which in turn affects imaging performance.
Date: March 9, 2003
Creator: Barty, A. & Goldberg, K.
System: The UNT Digital Library
Anisotropic flow in the forward directions at {radical}s{sub NN} = 200 GeV (open access)

Anisotropic flow in the forward directions at {radical}s{sub NN} = 200 GeV

The addition of the two Forward TPCs to the STAR detector allows one to measure anisotropic flow at forward pseudorapidities. This made possible the first measurement of directed flow at collision energies of {radical}s{sub NN} = 200 GeV. PHOBOS' results on elliptic flow at forward rapidities were confirmed, and the sign of v{sub 2} was determined to be positive for the first time at RHIC energies. The higher harmonic, v{sub 4}, is consistent with the recently suggested v{sub 2}2 scaling behavior.
Date: March 9, 2004
Creator: Oldenburg, Markus D.
System: The UNT Digital Library