(Test and gather data on sweep spike combination tillage tool) (open access)

(Test and gather data on sweep spike combination tillage tool)

This summary presents the data accumulated to date with only brief comment. It is prepared with the intent that the viewers will offer advice on terminology, data presentation, methods and other. The year end analysis will detail changes in the data due to the tillage treatments. The data is incomplete due to equipment problems and time limitations due to the wet fall and early freeze up. The trial was not completed due to our inability to get the Mikkelsen Chisel Plow Shovel (MCP), a 16 inch sweep with an anhydrous knife, to penetrate untilled land. The MCP shovel penetrated to deep on plowed ground and pulled so hard that the front wheels of our JD4440 tractor were jerked off the ground. The Standard Chisel Plow Shovels (SCP), a 16 inch sweep, worked well and the data is included.
Date: June 19, 1992
Creator: Lukach, J.
Object Type: Report
System: The UNT Digital Library
High temperature ceramic membrane reactors for coal liquid upgrading (open access)

High temperature ceramic membrane reactors for coal liquid upgrading

In this project we well evaluate the performance of Sel-Gel alumina membranes in coal liquid upgrading processes under realistic temperature and pressure conditions and investigate the feasibility of using such membranes in a membrane reactor based coal liquid upgrading process. In addition, the development of novel ceramic membranes with enhanced catalytic activity for coal-liquid upgrading applications, such as carbon-coated alumina membranes, will be also investigated. (VC)
Date: June 19, 1992
Creator: Tsotsis, T.T.
Object Type: Report
System: The UNT Digital Library
Ferrules seals (open access)

Ferrules seals

A device is provided for sealing an inner tube and an outer tube without excessively deforming the tubes. The device includes two ferrules which cooperate to form a vacuum-tight seal between the inner tube and outer tube and having mating surfaces such that overtightening is not possible.
Date: June 19, 1981
Creator: Smith, J.L.
Object Type: Patent
System: The UNT Digital Library
Free-electron laser using rf-coupled accelerating and decelerating structures (open access)

Free-electron laser using rf-coupled accelerating and decelerating structures

A free electron laser and free electron laser amplifier using beam transport devices for guiding an electron beam to a wiggler of a free electron laser and returning the electron beam to decelerating cavities disposed adjacent to the accelerating cavities of the free electron laser. Rf energy is extracted from the electron beam after it emerges from the wiggler by means of the decelerating cavities which are closely coupled to the accelerating cavities, or by means of a second bore within a single set of cavities. Rf energy extracted from the decelerated electron beam is used to supplement energy provided by an external source, such as a klystron, to thereby enhance overall efficiency of the system.
Date: June 19, 1981
Creator: Brau, C.A.; Swenson, D.A. & Boyd, T.J. Jr.
Object Type: Patent
System: The UNT Digital Library
High temperature ceramic membrane reactors for coal liquid upgrading (open access)

High temperature ceramic membrane reactors for coal liquid upgrading

Ceramic membranes are a new class of materials, which have shown promise in a variety of industrial applications. Their mechanical and chemical stability coupled with a wide range of operating temperatures and pressures make them suitable for environments found in coal liquid upgrading. In this project we will evaluate the performance of Sel-Gel alumina membranes in coal liquid upgrading processes under realistic temperature and pressure conditions and investigate the feasibility of using such membranes in a membrane reactor based coal liquid upgrading process. In addition, the development of novel ceramic membranes with enhanced catalytic activity for coal-liquid upgrading applications, such as carbon-coated alumina membranes, will also be investigated.
Date: June 19, 1992
Creator: Tsotsis, T.T.
Object Type: Report
System: The UNT Digital Library
High temperature ceramic membrane reactors for coal liquid upgrading (open access)

High temperature ceramic membrane reactors for coal liquid upgrading

Ceramic membranes are a new class of materials, which have shown promise in a variety of industrial applications. Their mechanical and chemical stability coupled with a wide range of operating temperatures and pressures make them suitable for environments found in coal liquid upgrading. In this project we will evaluate the performance of Sel-Gel alumina membranes in coal liquid upgrading processes under realistic temperature and pressure conditions and investigate the feasibility of using such membranes in a membrane reactor based coal liquid upgrading process. In addition, the development of novel ceramic membranes with enhanced catalytic activity for coal-liquid upgrading applications, such as carbon-coated alumina membranes, will be also investigated.
Date: June 19, 1992
Creator: Tsotsis, T.T.
Object Type: Report
System: The UNT Digital Library
PREPARATION AND FABRICATION OF ThO$sub 2$ FUELS (open access)

PREPARATION AND FABRICATION OF ThO$sub 2$ FUELS

Dense partricles of ThO/sub 2/-UO/sub 2/ were prepared by a sol-gel process and vibratorily compacted into metal tubes to a density approaching 9.0 g/ cc. The steps in this method are all simple and can be carried out behind shielding, which is necessary for refabricating U/sup 233/ fuels. The sol-gel process consists of preparing a hydrous thoria sol, adding the U/sup 233/ as nitrate solution, evaporating to a gel, and finally calcining to almost theoretically dense oxide particles at orly 1150 deg C. The sol-gel-prepared oxide, after being sized, was compacted with a simple, inexpensive pneumatic vibrator. (auth)
Date: June 19, 1962
Creator: Ferguson, D.E.; Arnold, E.D.; Ernst, W.S. Jr. & Dean, O.C.
Object Type: Report
System: The UNT Digital Library
Accelerometer and strain gage evaluation (open access)

Accelerometer and strain gage evaluation

This document describes the method developed by Sandia National Laboratories (SNL) to evaluate transducer used in the design certification testing of nuclear material shipping packages. This testing project was performed by SNL for the Office of Civilian Radioactive Waste Management (OCRWM). This evaluation is based on the results of tests conducted to measure ruggedness, failure frequency, repeatability, and manufacturers' calibration data under both field and laboratory conditions. The results of these tests are provided and discussed. The transducer were selected for testing by surveying cask contractors and testing facilities. Important insights relating to operational characteristics of accelerometer types were gained during field testing. 11 refs., 105 figs., 16 tabs.
Date: June 19, 1991
Creator: Ammerman, D. J.; Madsen, M. M.; Uncapher, W. L.; Stenberg, D. R. & Bronowski, D. R.
Object Type: Report
System: The UNT Digital Library
Discrete-event simulation of nuclear-waste transport in geologic sites subject to disruptive events. Final report (open access)

Discrete-event simulation of nuclear-waste transport in geologic sites subject to disruptive events. Final report

This report outlines a methodology to study the effects of disruptive events on nuclear waste material in stable geologic sites. The methodology is based upon developing a discrete events model that can be simulated on the computer. This methodology allows a natural development of simulation models that use computer resources in an efficient manner. Accurate modeling in this area depends in large part upon accurate modeling of ion transport behavior in the storage media. Unfortunately, developments in this area are not at a stage where there is any consensus on proper models for such transport. Consequently, our work is directed primarily towards showing how disruptive events can be properly incorporated in such a model, rather than as a predictive tool at this stage. When and if proper geologic parameters can be determined, then it would be possible to use this as a predictive model. Assumptions and their bases are discussed, and the mathematical and computer model are described.
Date: June 19, 1980
Creator: Aggarwal, S.; Ryland, S. & Peck, R.
Object Type: Report
System: The UNT Digital Library
High-temperature electrically conductive ceramic and method for making same (open access)

High-temperature electrically conductive ceramic and method for making same

It is the primary objective or aim of the present invention to provide an electrically conductive composition for the fabrication of susceptors useful for induction melting of uranium and uranium alloys and to also provide such a composition for forming crucibles and other containment vessels utilized to contain uranium at elevated temperatures. This composition does not appear to interact with molten uranium, since there is no significant reaction between the compositional consituents of the susceptor or containment vessel and the confined uranium. This objective is achieved by utilizing a sintered ceramic composition which consists essentially of about 13-67 vol. % of a refractory metal carbide and a nonconductive oxide selected from a group consisting of zirconium oxide, calcium aluminate, yttria, and combinations thereof.
Date: June 19, 1981
Creator: Holcombe, C.E. Jr. & Masters, D.R.
Object Type: Patent
System: The UNT Digital Library
High temperature ceramic membrane reactors for coal liquid upgrading (open access)

High temperature ceramic membrane reactors for coal liquid upgrading

Ceramic membranes are a new class of materials, which have shown promise in a variety of industrial applications. Their mechanical and chemical stability coupled with a wide range of operating temperatures and pressures make them suitable for environments found in coal liquid upgrading. In this project we will evaluate the performance of Sel-Gel alumina membranes in coal liquid upgrading processes under realistic temperature and pressure conditions and investigate the feasibility of using such membranes in a membrane reactor based coal liquid upgrading process. In addition, the development of novel ceramic membranes with enhanced catalytic activity for coal-liquid upgrading applications, such as carbon-coated alumina membranes, will be also investigated.
Date: June 19, 1992
Creator: Tsotsis, T.T.
Object Type: Report
System: The UNT Digital Library
GENERATION OF SUBPICOSECOND X-RAY PULSES IN STORAGE RINGS (open access)

GENERATION OF SUBPICOSECOND X-RAY PULSES IN STORAGE RINGS

Supicosecond x-ray pulses are routinely produced at ALS,BESSY and SLS with slicing technique and used in pump-probe experimentswith controlled delay between laser pump pulses and x-ray probe pulses.New development aiming for a production of a subpicosecond x-ray pulsesusing rf orbit deflection technique is under way at APS. Both techniqueswill be reviewed here.
Date: June 19, 2007
Creator: Zholents, Alexander A.
Object Type: Article
System: The UNT Digital Library
CARBON NANOMATERIALS AS CATALYSTS FOR HYDROGEN UPTAKE AND RELEASE IN NAALH4 (open access)

CARBON NANOMATERIALS AS CATALYSTS FOR HYDROGEN UPTAKE AND RELEASE IN NAALH4

A synergistic approach involving experiment and first-principles theory not only shows that carbon nanostructures can be used as catalysts for hydrogen uptake and release in complex metal hydrides such as sodium alanate, NaAlH{sub 4}, but also provides an unambiguous understanding of how the catalysts work. The stability of NaAlH{sub 4} originates from the charge transfer from Na to the AlH{sub 4} moiety, resulting in an ionic bond between Na{sup +} and AlH{sub 4}{sup -} and a covalent bond between Al and H. Interaction of NaAlH{sub 4} with an electro-negative substrate such as carbon fullerene or nanotube affects the ability of Na to donate its charge to AlH{sub 4}, consequently weakening the Al-H bond and causing hydrogen to desorb at lower temperatures as well as facilitating the absorption of H{sub 2} to reverse the dehydrogenation reaction. Ab initio molecular dynamics simulation further reveals the time evolution of the charge transfer process with hydrogen desorption occurring when the charge transfer is complete.
Date: June 19, 2008
Creator: Berseth, P; Ragaiy Zidan, R & Andrew Harter, A
Object Type: Article
System: The UNT Digital Library
Qcd Spin Physics in Hadronic Interactions. (open access)

Qcd Spin Physics in Hadronic Interactions.

We discuss spin phenomena in high-energy hadronic scattering, with a particular emphasis on the spin physics program now underway at the first polarized proton-proton collider, RHIC. Experiments at RHIC unravel the spin structure of the nucleon in new ways. Prime goals are to determine the contribution of gluon spins to the proton spin, to elucidate the flavor structure of quark and antiquark polarizations in the nucleon, and to help clarify the origin of transverse-spin phenomena in QCD. These lectures describe some aspects of this program and of the associated physics.
Date: June 19, 2007
Creator: Vogelsang, W.
Object Type: Article
System: The UNT Digital Library
Final Report for "Implimentation and Evaluation of Multigrid Linear Solvers into Extended Magnetohydrodynamic Codes for Petascale Computing" (open access)

Final Report for "Implimentation and Evaluation of Multigrid Linear Solvers into Extended Magnetohydrodynamic Codes for Petascale Computing"

Extended magnetohydrodynamic (MHD) codes are used to model the large, slow-growing instabilities that are projected to limit the performance of International Thermonuclear Experimental Reactor (ITER). The multiscale nature of the extended MHD equations requires an implicit approach. The current linear solvers needed for the implicit algorithm scale poorly because the resultant matrices are so ill-conditioned. A new solver is needed, especially one that scales to the petascale. The most successful scalable parallel processor solvers to date are multigrid solvers. Applying multigrid techniques to a set of equations whose fundamental modes are dispersive waves is a promising solution to CEMM problems. For the Phase 1, we implemented multigrid preconditioners from the HYPRE project of the Center for Applied Scientific Computing at LLNL via PETSc of the DOE SciDAC TOPS for the real matrix systems of the extended MHD code NIMROD which is a one of the primary modeling codes of the OFES-funded Center for Extended Magnetohydrodynamic Modeling (CEMM) SciDAC. We implemented the multigrid solvers on the fusion test problem that allows for real matrix systems with success, and in the process learned about the details of NIMROD data structures and the difficulties of inverting NIMROD operators. The further success of this …
Date: June 19, 2008
Creator: Vadlamani, Srinath; Kruger, Scott & Austin, Travis
Object Type: Report
System: The UNT Digital Library
Three-Dimensional Quasistatic Model for High Brightness Beam Dynamics Simulation (open access)

Three-Dimensional Quasistatic Model for High Brightness Beam Dynamics Simulation

In this paper, we present a three-dimensional quasistatic model for high brightness beam dynamics simulation in rf/dc photoinjectors, rf linacs, and similar devices on parallel computers. In this model, electrostatic space-charge forces within a charged particle beam are calculated self-consistently at each time step by solving the three-dimensional Poisson equation in the beam frame and then transforming back to the laboratory frame. When the beam has a large energy spread, it is divided into a number of energy bins or slices so that the space-charge forces are calculated from the contribution of each bin and summed together. Image-charge effects from conducting photocathode are also included efficiently using a shifted-Green function method. For a beam with large aspect ratio, e.g., during emission, an integrated Green function method is used to solve the three-dimensional Poisson equation. Using this model, we studied beam transport in one Linac Coherent Light Sources photoinjector design through the first traveling wave linac with initial misalignment with respect to the accelerating axis.
Date: June 19, 2006
Creator: Qiang, Ji; Lidia, S.; Ryne, R. D. & Limborg-Deprey, C.
Object Type: Article
System: The UNT Digital Library
CLOSURE OF HLW TANKS PHASE 2 FULL SCALE COOLING COILS GROUT FILL DEMONSTATIONS (open access)

CLOSURE OF HLW TANKS PHASE 2 FULL SCALE COOLING COILS GROUT FILL DEMONSTATIONS

This report documents the Savannah River National Laboratory (SRNL) support for the Tank Closure and Technology Development (TCTD) group's strategy for closing high level radioactive waste (HLW) tanks at the Savannah River Site (SRS). Specifically, this task addresses the ability to successfully fill intact cooling coils, presently within the HLW tanks, with grout that satisfies the fresh and cured grout requirements [1] under simulated field conditions. The overall task was divided into two phases. The first phase was the development of a grout formulation that satisfies the processing requirements for filling the HLW tank cooling coils [5]. The second phase of the task, which is documented in this report, was the filling of full scale cooling coils under simulated field conditions using the grout formulation developed in the first phase. SRS Type I tank cooling coil assembly design drawings and pressure drop calculations were provided by the Liquid Waste (LW) customer to be used as the basis for configuring the test assemblies. The current concept for closing tanks equipped with internal cooling coils is to pump grout into the coils to inhibit pathways for infiltrating water. Access to the cooling coil assemblies is through the existing supply/return manifold headers located …
Date: June 19, 2008
Creator: Hansen, E & Alex Cozzi, A
Object Type: Report
System: The UNT Digital Library
Measurements and Analysis of Helium-Like Triplet Ratios in the X-Ray Spectra of O-Type Stars (open access)

Measurements and Analysis of Helium-Like Triplet Ratios in the X-Ray Spectra of O-Type Stars

We discuss new methods of measuring and interpreting the forbidden-to-intercombination line ratios of helium-like triplets in the X-ray spectra of O-type stars, including accounting for the spatial distribution of the X-ray emitting plasma and using the detailed photospheric UV spectrum. Measurements are made for four O stars using archival Chandra HETGS data. We assume an X-ray emitting plasma spatially distributed in the wind above some minimum radius R{sub 0}. We find minimum radii of formation typically in the range of 1.25 < R{sub 0}/R{sub *} < 1.67, which is consistent with results obtained independently from line profile fits. We find no evidence for anomalously low f/i ratios and we do not require the existence of X-ray emitting plasmas at radii that are too small to generate sufficiently strong shocks.
Date: June 19, 2006
Creator: Leutenegger, Maurice A.; Paerels, Frits B. S.; Kahn, Steven M. & Cohen, David H.
Object Type: Article
System: The UNT Digital Library
The New Element Californium (Atomic Number 98) (open access)

The New Element Californium (Atomic Number 98)

Definite identification has been made of an isotope of the element with atomic number 98 through the irradiation of Cm{sup 242} with about 35-Mev helium ions in the Berkeley Crocker Laboratory 60-inch cyclotron. The isotope which has been identified has an observed half-life of about 45 minutes and is thought to have the mass number 244. The observed mode of decay of 98{sup 244} is through the emission of alpha-particles, with energy of about 7.1 Mev, which agrees with predictions. Other considerations involving the systematics of radioactivity in this region indicate that it should also be unstable toward decay by electron capture. The chemical separation and identification of the new element was accomplished through the use of ion exchange adsorption methods employing the resin Dowex-50. The element 98 isotope appears in the eka-dysprosium position on elution curves containing berkelium and curium as reference points--that is, it precedes berkelium and curium off the column in like manner that dysprosium precedes terbium and gadolinium. The experiments so far have revealed only the tripositive oxidation state of eka-dysprosium character and suggest either that higher oxidation states are not stable in aqueous solutions or that the rates of oxidation are slow. The successful identification …
Date: June 19, 1950
Creator: Thompson, S. G.; Street Jr., K.; Ghiorso, A. & Seaborg, G. T.
Object Type: Report
System: The UNT Digital Library
Isotopically controlled semiconductors (open access)

Isotopically controlled semiconductors

The following article is an edited transcript based on the Turnbull Lecture given by Eugene E. Haller at the 2005 Materials Research Society Fall Meeting in Boston on November 29, 2005. The David Turnbull Lectureship is awarded to recognize the career of a scientist who has made outstanding contributions to understanding materials phenomena and properties through research, writing, and lecturing, as exemplified by the life work of David Turnbull. Haller was named the 2005 David Turnbull Lecturer for his 'pioneering achievements and leadership in establishing the field of isotopically engineered semiconductors; for outstanding contributions to materials growth, doping and diffusion; and for excellence in lecturing, writing, and fostering international collaborations'. The scientific interest, increased availability, and technological promise of highly enriched isotopes have led to a sharp rise in the number of experimental and theoretical studies with isotopically controlled semiconductor crystals. This article reviews results obtained with isotopically controlled semiconductor bulk and thin-film heterostructures. Isotopic composition affects several properties such as phonon energies, band structure, and lattice constant in subtle, but, for their physical understanding, significant ways. Large isotope-related effects are observed for thermal conductivity in local vibrational modes of impurities and after neutron transmutation doping. Spectacularly sharp photoluminescence lines …
Date: June 19, 2006
Creator: Haller, Eugene E.
Object Type: Article
System: The UNT Digital Library
First Wall and Operational Diagnostics (open access)

First Wall and Operational Diagnostics

In this chapter we review numerous diagnostics capable of measurements at or near the first wall, many of which contribute information useful for safe operation of a tokamak. There are sections discussing infrared cameras, visible and VUV cameras, pressure gauges and RGAs, Langmuir probes, thermocouples, and erosion and deposition measurements by insertable probes and quartz microbalance. Also discussed are dust measurements by electrostatic detectors, laser scattering, visible and IR cameras, and manual collection of samples after machine opening. In each case the diagnostic is discussed with a view toward application to a burning plasma machine such as ITER.
Date: June 19, 2006
Creator: Lasnier, C.; Allen, S.; Boedo, J.; Groth, M.; Brooks, N.; McLean, A. et al.
Object Type: Article
System: The UNT Digital Library
Synthesis and Electrochemistry of Li3MnO4: Mn in the +5 OxidationState (open access)

Synthesis and Electrochemistry of Li3MnO4: Mn in the +5 OxidationState

Computational and experimental work directed at exploringthe electrochemical properties of tetrahedrally coordinated Mn in the +5oxidation state is presented. Specific capacities of nearly 700 mAh/g arepredicted for the redox processes of LixMnO4 complexes based on twotwo-phase reactions. One is topotactic extractionof Li from Li3MnO4 toform LiMnO4 and the second is topotactic insertion of Li into Li3MnO4 toform Li5MnO4. In experiments, it is found that the redox behavior ofLi3MnO4 is complicated by disproportionation of Mn5+ in solution to formMn4+ and Mn7+ and byother irreversible processes; although an initialcapacity of about 275 mAh/g in lithiumcells was achieved. Strategiesbased on structural considerations to improve the electrochemicalproperties of MnO4n- complexes are given.
Date: June 19, 2007
Creator: Saint, Juliette.A.; Doeff, Marca M. & Reed, John
Object Type: Article
System: The UNT Digital Library
Survey of Collective Instabilities and Beam-Plasma Interactions in Intense Heavy Ion Beams (open access)

Survey of Collective Instabilities and Beam-Plasma Interactions in Intense Heavy Ion Beams

This paper presents a survey of the present theoretical understanding based on advanced analytical and numerical studies of collective processes and beam-plasma interactions in intense heavy ion beams for applications to ion-beam-driven high energy density physics and heavy ion fusion. The topics include: discussion of the conditions for quiescent beam propagation over long distances; and the electrostatic Harris instability and the transverse electromagnetic Weibel instability in highly anisotropic, intense one-component ion beams. In the longitudinal drift compression and transverse compression regions, collective processes associated with the interaction of the intense ion beam with a charge-neutralizing background plasma are described, including the electrostatic electron-ion two-stream instability, the multispecies electromagnetic Weibel instability, and collective excitations in the presence of a solenoidal magnetic field. The effects of a velocity tilt on reducing two-stream instability growth rates are also discussed. Operating regimes are identified where the possible deleterious effects of collective processes on beam quality are minimized.
Date: June 19, 2008
Creator: Davidson, Ronald C.; Dorf, Mikhail A.; Kaganovich, Igor D.; Qin, Hong; Startsev, Edward A.; Rose, David V. et al.
Object Type: Article
System: The UNT Digital Library
Integrated Global Nuclear Materials Management Preliminary Concepts (open access)

Integrated Global Nuclear Materials Management Preliminary Concepts

The world is at a turning point, moving away from the Cold War nuclear legacy towards a future global nuclear enterprise; and this presents a transformational challenge for nuclear materials management. Achieving safety and security during this transition is complicated by the diversified spectrum of threat 'players' that has greatly impacted nonproliferation, counterterrorism, and homeland security requirements. Rogue states and non-state actors no longer need self-contained national nuclear expertise, materials, and equipment due to availability from various sources in the nuclear market, thereby reducing the time, effort and cost for acquiring a nuclear weapon (i.e., manifestations of latency). The terrorist threat has changed the nature of military and national security requirements to protect these materials. An Integrated Global Nuclear Materials Management (IGNMM) approach would address the existing legacy nuclear materials and the evolution towards a nuclear energy future, while strengthening a regime to prevent nuclear weapon proliferation. In this paper, some preliminary concepts and studies of IGNMM will be presented. A systematic analysis of nuclear materials, activities, and controls can lead to a tractable, integrated global nuclear materials management architecture that can help remediate the past and manage the future. A systems approach is best suited to achieve multi-dimensional and …
Date: June 19, 2006
Creator: Jones, E & Dreicer, M
Object Type: Article
System: The UNT Digital Library