Resource Type

The cost of transportation`s oil dependence (open access)

The cost of transportation`s oil dependence

Transportation is critical to the world`s oil dependence problem because of the large share of world oil it consumes and because of its intense dependence on oil. This paper will focus on the economic costs of transportation`s oil dependence.
Date: May 1, 1995
Creator: Greene, D. L.
System: The UNT Digital Library
18th U.S. Department of Energy Low-Level Radioactive Waste Management Conference. Program (open access)

18th U.S. Department of Energy Low-Level Radioactive Waste Management Conference. Program

This conference explored the latest developments in low-level radioactive waste management through presentations from professionals in both the public and the private sectors and special guests. The conference included two continuing education seminars, a workshop, exhibits, and a tour of Envirocare of Utah, Inc., one of America's three commercial low-level radioactive waste depositories.
Date: May 20, 1997
Creator: unknown
System: The UNT Digital Library
TEM investigation of a ceramic waste form for immobilization of process salts generated during electrometallurgical treatment of spent nuclear fuel. (open access)

TEM investigation of a ceramic waste form for immobilization of process salts generated during electrometallurgical treatment of spent nuclear fuel.

Transmission electron microscopy (TEM) examination is presented of the microstructure of a ceramic waste form developed at Argonne National Lab - West for immobilization of actinides and fission products present in an electrorefiner salt. The material is produced by occluding the salt in zeolite granules, followed by hot isostatic pressing of the occluded zeolite in a mixture with a borosilicate glass. The paper presents results from a cold surrogate ceramic waste form, as well as {sup 239}Pu and {sup 238}Pu loaded samples.
Date: May 6, 1999
Creator: Esh, D. W.; Frank, S. M.; Goff, K. M.; Johnson, S. G.; Moschetti, T. L.; O'Holleran, T. P. et al.
System: The UNT Digital Library
Realtime tune measurements in slow-cycling accelerators (open access)

Realtime tune measurements in slow-cycling accelerators

None
Date: May 1, 1997
Creator: Herrup, D.
System: The UNT Digital Library
Laser induced damage in multilayer dielectric gratings due to ultrashort laser pulses (open access)

Laser induced damage in multilayer dielectric gratings due to ultrashort laser pulses

Chirped pulse amplification is increasingly used to produce intense ultrashort laser pulses. When high-efficiency gratings are the dispersive element, as in the LLNL Petawatt laser, their susceptibility to laser induced damage constitutes a limitation on the peak intensities that can be reached. To obtain robust gratings, it is necessary to understand the causes of short-pulse damage, and to recognize the range of design options for high efficiency gratings. Metal gratings owe their high efficiency to their high conductivity. To avoid the inevitable light absorption that accompanies conductivity, we have developed designs for high efficiency reflection gratings that use only transparent dielectric materials. These combine the reflectivity of a multilayer dielectric stack with a diffraction grating. We report here our present understanding of short-pulse laser induced damage, as it applies to dielectric gratings.
Date: May 26, 1995
Creator: Shore, B. W.; Stuart, B. C.; Feit, M. D.; Rubenchik, A. M. & Perry, M. D.
System: The UNT Digital Library
Dynamics sensor validation for reusable launch vehicle propulsion. (open access)

Dynamics sensor validation for reusable launch vehicle propulsion.

Expert Microsystems teamed with Argonne National Laboratory (ANL), a DOE contractor, to develop an innovative dynamics sensor validation system under a Small Business Technology Transfer (STTR) Phase I contract with NASA. The project improves launch vehicle mission safety and system dependability by enabling rapid development and cost effective maintenance of embeddable real-time software to reliably detect process-critical sensor failures. The project focused on verifying the feasibility of two innovative software methods developed by ANL to provide high fidelity sensor data validation for nuclear power generating stations, the Sequential Probability Ratio Test (SPRT) algorithm and the Multivariate State Estimation Technique (MSET) algorithm, as core elements of a commercial Dynamics Sensor Validation System (DSVS). The research verified that ANL algorithms enable highly reliable data validation for high frequency Space Shuttle Main Engine (SSME) dynamics sensors, such as accelerometers and strain gauges. Phase I culminated in production of a prototype run-time module which validates SSME flight accelerometer data with very high reliability. The resulting sensor validation development system is widely applicable to reusable launch vehicle (RLV) and ground support control and monitoring systems.
Date: May 27, 1998
Creator: Herzog, J. P.
System: The UNT Digital Library
Towards standardizing the measurement of electrochemical properties of solid state electrolytes in lithium batteries. (open access)

Towards standardizing the measurement of electrochemical properties of solid state electrolytes in lithium batteries.

The purpose of this paper is to stimulate thought and discussion in the technical community on standardization of the experimental determination of the pertinent electrochemical properties of solid electrolytes in lithium batteries. This standardization is needed for comparison and modeling of solid electrolytes in a practical lithium battery. The appropriate electrochemical properties include transport, thermodynamic, and physical parameters that generally depend on concentration and temperature. While it is beyond the scope of this work to put forward definitive measurement techniques for all types of solid electrolytes, it is hoped that comparisons between various techniques to examine a dissolved binary lithium salt in a dry polymer solvent will lead to improved understanding and methodology for examining solid electrolytes.
Date: May 6, 1999
Creator: Dees, D. W. & Henriksen, G. L.
System: The UNT Digital Library
Some results from the second iteration of total-system performance assessment for Yucca Mountain (open access)

Some results from the second iteration of total-system performance assessment for Yucca Mountain

The second preliminary total-system performance assessment for the potential radioactive-waste-repository site at Yucca Mountain has recently been completed. This paper summarizes results for nominal aqueous and gaseous releases using the composite-porosity flow model. The results are found to be sensitive to the type of unsaturated-zone flow, to percolation flux and climate change, to saturated-zone dilution, to container-wetting processes and container-corrosion processes, to fuel-matrix alteration rate and radionuclide solubilities (especially for {sup 237}Np), and to bulk permeability and retardation of gaseous {sup 14}C. These are areas that should be given priority in the site-characterization program. Specific recommendations are given in the full report of the study.
Date: May 1, 1994
Creator: Wilson, M. L.
System: The UNT Digital Library
Applications of texture mapping to volume and flow visualization (open access)

Applications of texture mapping to volume and flow visualization

The authors describe six visualization methods which take advantage of hardware polygon scan conversion, texture mapping, and compositing, to give interactive viewing of 3D scalar fields, and motion for 3D flows. For volume rendering, these are splatting of an optimized 3D reconstruction filter, and tetrahedral cell projection using a texture map to provide the exponential per pixel necessary for accurate opacity calculation. For flows, these are the above tetrahedral projection method for rendering the ``flow volume`` dyed after passing through a dye releasing polygon, ``splatting`` of cycled anisotropic textures to provide flow direction and motion visualization, splatting motion blurred particles to indicate flow velocity, and advecting a texture directly to show the flow motion. All these techniques are tailored to take advantage of existing graphics pipelines to produce interactive visualization tools.
Date: May 1, 1995
Creator: Max, N.; Crawfis, R. & Becker, B.
System: The UNT Digital Library
Metal waste forms from treatment of EBR-II spent fuel. (open access)

Metal waste forms from treatment of EBR-II spent fuel.

Demonstration of Argonne National Laboratory's electrometallurgical treatment of spent nuclear fuel is currently being conducted on irradiated, metallic driver fuel and blanket fuel elements from the Experimental Breeder Reactor-II (EBR-II) in Idaho. The residual metallic material from the electrometallurgical treatment process is consolidated into an ingot, the metal waste form (MWF), by employing an induction furnace in a hot cell. Scanning electron microscopy (SEM) and chemical analyses have been performed on irradiated cladding hulls from the driver fuel, and on samples from the alloy ingots. This paper presents the microstructures of the radioactive ingots and compares them with observations on simulated waste forms prepared using non-irradiated material. These simulated waste forms have the baseline composition of stainless steel - 15 wt % zirconium (SS-15Zr). Additions of noble metal elements, which serve as surrogates for fission products, and actinides are made to that baseline composition. The partitioning of noble metal and actinide elements into alloy phases and the role of zirconium for incorporating these elements is discussed in this paper.
Date: May 18, 1998
Creator: Abraham, D. P.
System: The UNT Digital Library
Photorefractivity in polymer-stabilized liquid crystals films. (open access)

Photorefractivity in polymer-stabilized liquid crystals films.

We have shown that PSLCs are capable of forming photorefractive gratings that operate in the thick grating regime. Polymer stabilization alters the charge transport and trapping characteristics of LCs, resulting in longer lived gratings, while maintaining the advantages of high orientational birefringence within LCs. Furthermore, very low applied electric fields (800 V/cm) and low optical intensities (100 mW/cm{sup 2}) are required to create large photorefractive effects in these materials. It is expected that optimization of the redox potentials of the chromophores within the PSLCs will continue to improve the performance of these materials.
Date: May 8, 1998
Creator: Wasielewski, M. R.
System: The UNT Digital Library
A new approach in utilizing a computer data acquisition system for criticality safety control (open access)

A new approach in utilizing a computer data acquisition system for criticality safety control

A new approach in utilizing a computer data acquisition system is proposed to address many issues associated with criticality safety control. This Criticality Safety Support System (CSSS) utilizes many features of computer and information process technology such as digital pictures, barcodes, voice data entry, etc. to enhance criticality safety in an R and D environment. Due to on-line data retrieving, data recording, and data management offered by new technology, the CSSS would provide a framework to design new solutions to old problems. This pilot program is the first step in developing this application for the years to come.
Date: May 6, 1999
Creator: Hopkins, H; Song, H & Warren, F
System: The UNT Digital Library
An inverse Cherenkov accelerator using a dielectric channeled waveguide. (open access)

An inverse Cherenkov accelerator using a dielectric channeled waveguide.

None
Date: May 22, 1998
Creator: Gai, W.
System: The UNT Digital Library
Success criteria for the electrometallurgical treatment demonstration. (open access)

Success criteria for the electrometallurgical treatment demonstration.

Argonne National Laboratory is demonstrating the application of electrometallurgical treatment processes to Experimental Breeder Reactor-II spent nuclear fuel. Begun in June 1996, 100 driver fuel assemblies and 25 blanket fuel assemblies will be conditioned during this demonstration project. In order to validate the technical and economic viability of the technology, the Department of Energy has established four success criteria with specific supporting goals. The results from both laboratory-scale and engineering-scale testing are being used to evaluate the processes, products and equipment against the target goals. The interim results have provided confidence that the integrated electrometallurgical processes will prove to be a viable option for treating problematic spent nuclear fuels for geologic disposal.
Date: May 4, 1998
Creator: Benedict, R. W.
System: The UNT Digital Library
Structure and property relationship in the mixed-conducting Sr-Fe-Co-O system. (open access)

Structure and property relationship in the mixed-conducting Sr-Fe-Co-O system.

Mixed-conducting ceramic oxides have potential uses in high-temperature electrochemical applications such as solid oxide fuel cells, advanced batteries, sensors, and oxygen-permeable membranes. The Sr-Fe-Co-O system combines high electronic/ionic conductivity with appreciable oxygen permeability at elevated temperatures. Dense ceramic membranes made of this material can be used to separate high-purity oxygen from air without the need for external electrical circuitry, or to partially oxidize methane to produce syngas. Samples of Sr{sub 2}Fe{sub 3{minus}x}Co{sub x}O{sub y} (with x = 0, 0.6, 1.0, and 1.4) were prepared by solid-state reaction in atmospheres with various oxygen partial pressures (pO{sub 2}) and were characterized by X-ray diffraction, scanning electron microscopy, and electrical conductivity measurements. Phase components of the samples are dependent on cobalt concentration and synthesis pO{sub 2}. Total conductivity increases with increasing temperature and cobalt content in the material. Higher ionic transference numbers have been observed in samples with lower cobalt contents. Current-voltage characteristics determined in a gas-tight cell indicate that a bulk effect, rather than a surface exchange effect, is the main limiting factor for oxygen permeation through membranes made of Sr{sub 2}Fe{sub 2}CoO{sub y}. Oxygen permeability measurements at various temperatures showed that oxygen permeability increases with increasing temperature, as expected. At 900 …
Date: May 18, 1998
Creator: Ma, B.
System: The UNT Digital Library
Precision analog signal processor for beam position measurements in electron storage rings (open access)

Precision analog signal processor for beam position measurements in electron storage rings

Beam position monitors (BPM) in electron and positron storage rings have evolved from simple systems composed of beam pickups, coaxial cables, multiplexing relays, and a single receiver (usually a analyzer) into very complex and costly systems of multiple receivers and processors. The older may have taken minutes to measure the circulating beam closed orbit. Today instrumentation designers are required to provide high-speed measurements of the beam orbit, often at the ring revolution frequency. In addition the instruments must have very high accuracy and resolution. A BPM has been developed for the Advanced Light Source (ALS) in Berkeley which features high resolution and relatively low cost. The instrument has a single purpose; to measure position of a stable stored beam. Because the pickup signals are multiplexed into a single receiver, and due to its narrow bandwidth, the receiver is not intended for single-turn studies. The receiver delivers normalized measurements of X and Y posit ion entirely by analog means at nominally 1 V/mm. No computers are involved. No software is required. Bergoz, a French company specializing in precision beam instrumentation, integrated the ALS design m their new BPM analog signal processor module. Performance comparisons were made on the ALS. In this …
Date: May 1, 1995
Creator: Hinkson, J. A. & Unser, K. B.
System: The UNT Digital Library
Fermi surfaces, Fermi patches, and Fermi arcs in high T{sub c} superconductors. (open access)

Fermi surfaces, Fermi patches, and Fermi arcs in high T{sub c} superconductors.

A defining property of metals is the existence of a Fermi surface: for two dimensions, a continuous contour in momentum space which separates occupied from unoccupied states. In this paper, I discuss angle resolved photoemission data on the cuprate superconductor BSCCO and argue that it is not best thought of in this conventional picture. Rather, the data are consistent with patches of finite area connected by more conventional arcs. Novel physics is associated with the patches, in that the states contained in a patch are dispersionless and thus interaction dominated. In the pseudogap phase, the patches are gapped out, leaving the Fermi arcs disconnected. This unusual situation may be the key to understanding the microscopic physics of the high temperature superconductors, in that the pairing correlations are strongest in the patches, yet the superfluid density lives only on the arcs.
Date: May 19, 1999
Creator: Norman, M. R.
System: The UNT Digital Library
Effect of ionizing radiation on the waste package environment (open access)

Effect of ionizing radiation on the waste package environment

The radiolytic production of nitrogen oxides, nitrogen acids and ammonia are discussed in relation to the expected environment in a high-level waste repository that may be constructed at the Yucca Mountain site if it is found to be suitable. Both literature data and repository-relevant data are summarized for air-water vapor systems. The limiting cases of a dry air and a pure water vapor gas phase are also discussed. Design guidelines and recommendations, based solely on the potential consequence of radiation enhancement of corrosion, are given. 13 refs., 5 figs., 1 tab.
Date: May 1, 1991
Creator: Reed, D.T. & Van Konynenburg, R.A.
System: The UNT Digital Library
Measurement of the top quark mass (open access)

Measurement of the top quark mass

The first evidence and subsequent discovery of the top quark was reported nearly 4 years ago. Since then, CDF and D0 have analyzed their full Run 1 data samples, and analysis techniques have been refined to make optimal use of the information. In this paper, we report on the most recent measurements of the top quark mass, performed by the CDF and D0 collaborations at the Fermilab Tevatron. The CDF collaboration has performed measurements of the top quark mass in three decay channels from which the top quark mass is measured to be 175.5 {+-} 6.9 GeV=c{sup 2}. The D0 collaboration combines measurements from two decay channels to obtain a top quark mass of 172.1 {+-} 7.1 GeV/c{sup 2}. Combining the measurements from the two experiments, assuming a 2 GeV GeV/c{sup 2} correlated systematic uncertainty, the measurement of the top quark mass at the Tevatron is 173.9 {+-} 5.2 GeV/c{sup 2}. This report presents the measurements of the top quark mass from each of the decay channels which contribute to this measurement.
Date: May 1, 1998
Creator: Blusk, Steven R.
System: The UNT Digital Library
International shipment of plutonium by air (open access)

International shipment of plutonium by air

In support of the United States (US) Government`s decision to place excess plutonium oxide at the US Department of Energy`s (DOE) Hanford Site under International Atomic Energy Agency (IAEA) safeguards, the Department of State notified the Congress that a plutonium storage vault at the Plutonium Finishing Plant at the Hanford Site would be added to the eligible facilities list. As part of the preparations to transfer the plutonium oxide under IAEA safeguards, samples of the powder were taken from the inventory to be shipped to the IAEA headquarters in Vienna, Austria, for laboratory analysis. The analysis of these samples was of high priority, and the IAEA requested that the material be shipped by aircraft, the most expeditious method.
Date: May 1, 1995
Creator: Mercado, J.E. & McGrogan, J.P.
System: The UNT Digital Library
Theoretical investigations of silver clusters and silver-ligand systems. (open access)

Theoretical investigations of silver clusters and silver-ligand systems.

Studies directed at understanding structural and electronic properties of silver clusters have been and remain the subject of an active theoretical [1-22] and experimental [23- 38] effort. One of the reasons is the (still) important role these systems play in the photographic process. Investigations of interactions of silver clusters with different atoms and molecules are motivated primarily by a possible utility of these clusters in catalytic processes. The important role of silver in the selective oxidation of ethylene into ethylene oxide, the feedstock for polyester production, is well-known [39]. Possible variations in chemical reactivity with the cluster size and understanding of the mechanisms of interactions with different ligands may lead to new and more efficient applications. Investigations of cluster-ligand systems also contribute a great deal to a better understanding of gas-surface interactions. Accordingly, theoretical studies of silver clusters and cluster-ligand systems [40-44] fall into two categories--those that use clusters as models for silver surfaces [40], and those that target clusters and cluster-ligand interactions as subjects in their own right [41-44]. The common goal of all these studies is to elucidate the nature of the interatomic interactions and bonding at the microscopic level and thereby arrive at a fundamental understanding and …
Date: May 19, 1999
Creator: Jellinek, J.; Salian, U. & Srinivas, S.
System: The UNT Digital Library
Calculation of the Invariant Spin Field by Adiabatically Blowing Up the Beam With an RF Dipole (open access)

Calculation of the Invariant Spin Field by Adiabatically Blowing Up the Beam With an RF Dipole

The Relativistic Heavy Ion Collider RHIC will collide polarized proton beams up to a maximum beam energy of 250 GeV [1]. The invariant spin field in a high energy ring can vary substantially across the beam. This decreases the amount of polarization provided to experiments and makes the polarization strongly dependent on the position in phase space. This paper describes a method to compute the invariant spin field by adiabatically blowing up the beam with an rf dipole. This method will also allow measuring the invariant spin field in RHIC.
Date: May 17, 1999
Creator: Lehrach, A.
System: The UNT Digital Library
Coupling various methods for convection-diffusion problems with applications to flows in porous media (open access)

Coupling various methods for convection-diffusion problems with applications to flows in porous media

None
Date: May 6, 1999
Creator: Lazrov, R D; Pasciak, J E & Vassilevski, P S
System: The UNT Digital Library
Development of mixed-conducting ceramic membranes for hydrogen separation. (open access)

Development of mixed-conducting ceramic membranes for hydrogen separation.

SrCeO{sub 3}- and BaCeO{sub 3}-based proton conductors have been prepared and their transport properties have been investigated by impedance spectroscopy in conjunction with open circuit voltage and water vapor evolution measurements. BaCe{sub 0.8}Y{sub 0.2}O{sub 3-{delta}} exhibits the highest conductivity in a hydrogen-containing atmosphere; however, its electronic conductivity is not adequate for hydrogen separation in a nongalvanic mode. In an effort to enhance ambipolar conductivity and improve interfacial catalytic properties, BaCe{sub 0.8}Y{sub 0.2}O{sub 3-{delta}} cermets have been fabricated into membranes. The effects of ambipolar conductivity, membrane thickness, and interfacial resistance on permeation rates have been investigated. In particular, the significance of interfacial resistance is emphasized.
Date: May 18, 1998
Creator: Guan, J.
System: The UNT Digital Library