Serial/Series Title
OIT Tip Sheets
10
Establishment of an Industry-Driven Consortium Focused on Improving the Production Performance of Domestic Stripper Wells Quarterly Report
8
Fiscal Year 2004
8
Enhanced Wellbore Stabilization and Reservoir Productivity with Aphron Drilling Fluid Technology
6
Fiscal Year 2003
6
Small Wind Electric Systems Consumers' Guides
6
Cost-Effective Reciprocating Engine Emissions Control and Monitoring for E&P Field and Gathering Engines Progress Report
4
Differential Soil Impedance Obstacle Detection Quarterly Report
4
Field Demonstration of a Membrane Process to Separate Nitrogen From Natural Gas Progress Report
4
Fundamentals of Reservoir Surface Energy as Related to Surface Properties, Wettability, Capillary Action, and Oil Recovery From Fractured Reservoirs by Spontaneous Imbibition Quarterly Report
4
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7,087 Matching Results
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Material dynamics at extreme pressures and strain rates
Solid state experiments at extreme pressures (10-100 GPa) and strain rates ({approx}10{sup 6}-10{sup 8}s{sup -1}) are being developed on high-energy laser facilities, and offer the possibility for exploring new regimes of materials science. [Re 2004] These extreme solid-state conditions can be accessed with either shock loading or with quasi-isentropic ramped pressure pulses being developed on the Omega laser. [Ed 2004] Velocity interferometer measurements establish the high strain rates. Constitutive models for solid-state strength under these conditions are tested by comparing 2D continuum simulations with experiments measuring perturbation growth due to the Rayleigh-Taylor instability in solid-state samples. Lattice compression, phase, and temperature are deduced from extended x-ray absorption fine structure (EXAFS) measurements, from which the shock-induced a-w phase transition in Ti is inferred to occur on sub-nanosecond time scales. [Ya 2004] Time resolved lattice response and phase can be inferred from dynamic x-ray diffraction measurements, where the elastic-plastic (1D-3D) lattice relaxation in shocked Cu is shown to occur promptly (< 1 ns). [Lo 2003] Subsequent large-scale MD simulations have elucidated the microscopic dynamics that underlie the 3D lattice relaxation. Deformation mechanisms are identified by examining the residual microstructure in recovered samples. [Re 2004] For example, the slip-twinning threshold in single-crystal Cu …
Date:
August 25, 2004
Creator:
Remington, Bruce A.; Cavallo, Rob M.; Edwards, Michael J.; Ho, David D.; Lasinski, Barbara F.; Lorenz, Karl T. et al.
Object Type:
Article
System:
The UNT Digital Library
Large plasma pressure perturbations and radial convective transport in a tokamak
Strongly localized plasma structures with large pressure inhomogeneities (such as plasma blobs in the scrape-off-layer (SOL)/shadow regions, pellet clouds, ELMs) observed in the tokamaks, stellarators and linear plasma devices. Experimental studies of these phenomena reveal striking similarities including more convective rather than diffusive radial plasma transport. We suggest that rather simple models can describe many essentials of blobs, ELMs, and pellet clouds dynamics. The main ingredient of these models is the effective plasma gravity caused by magnetic curvature, centrifugal or friction forces effects. As a result, the equations governing plasma transport in such localized structures appear to be rather similar to that used to describe nonlinear evolution of thermal convection in the Boussinesq approximation (directly related to the Rayleigh-Taylor instability).
Date:
February 4, 2004
Creator:
Krasheninnikov, S.; Ryutov, D. & Yu, G.
Object Type:
Article
System:
The UNT Digital Library
In-situ Diffraction Studies of Shock Compressed Single-Crystal Iron
The technique of in-situ wide angle diffraction has been used to study materials such as Si and Cu. We have extended our studies of shocked single crystal materials to include Fe (001) that is shock compressed by direct laser irradiation using the OMEGA and Janus lasers. A series of experiments was conducted in Fe at pressures above the Hugoniot Elastic Limit. Transient x-ray was used to record the response of multiple lattice planes simultaneously. This technique of wide-angle diffraction provides information on the lattice response both parallel and oblique to the shock propagation direction. In these experiments, compressions of up to 14% in the (002) planes were observed. Details on the experiments and analysis of the dynamic lattice compression will be presented.
Date:
July 16, 2004
Creator:
Kalantar, D H; Colvin, J D; Eggert, J; Lorenzana, H; Stolken, J; Hawreliak, J et al.
Object Type:
Article
System:
The UNT Digital Library
Monolithic Nickel (II) Oxide Aerogels Using an Organic Epoxide: The Importance of the Counter Ion
The synthesis and characterization of nickel (II) oxide aerogel materials prepared using the epoxide addition method is described. The addition of the organic epoxide propylene oxide to an ethanolic solution of NiCl{sub 2} 6H{sub 2}O resulted in the formation of an opaque light green monolithic gel and subsequent drying with supercritical CO{sub 2} gave a monolithic aerogel material of the same color. This material has been characterized using powder X-ray diffraction, electron microscopy, elemental analysis, and nitrogen adsorption/desorption analysis. The results indicate that the nickel (II) oxide aerogel has very low bulk density (98 kg/m{sup 3} ({approx}98 %porous)), high surface area (413 m{sup 2}/g), and has a particulate-type aerogel microstructure made up of very fine spherical particles with an open porous network. By comparison, a precipitate of Ni{sub 3}(NO{sub 3}){sub 2}(OH){sub 4} is obtained when the same preparation is attempted with the common Ni(NO{sub 3}){sub 2} 6H{sub 2}O salt as the precursor. The implications of the difference of reactivity of the two different precursors are discussed in the context of the mechanism of gel formation via the epoxide addition method. The synthesis of nickel (II) oxide aerogel, using the epoxide addition method, is especially unique in our experience. It is …
Date:
January 13, 2004
Creator:
Gash, A. E.; Satcher, J. H. & Simpson, R. L.
Object Type:
Article
System:
The UNT Digital Library
Mass by Energy Loss Quantitation as a Practical Sub-Microgram Balance
A simple device integrating a thin film support and a standard microcentrifuge tube can be used for making solutions of accurately known concentration of any organic compound in a single step, avoiding serial dilution and the use of microgram balances. Nanogram to microgram quantities of organic material deposited on the thin film are quantified by ion energy loss and transferred to the microcentrifuge tube with high recovery.
Date:
September 28, 2004
Creator:
Palmblad, M; Bench, G & Vogel, J S
Object Type:
Article
System:
The UNT Digital Library
Preventive Maintenance Strategies for Compressed Air Systems;Industrial Technologies Program (ITP) Compressed Air Tip Sheet No.6
BestPractices Program tip sheet discussing preventive maintenance strategies for compressed air systems.
Date:
August 1, 2004
Creator:
unknown
Object Type:
Text
System:
The UNT Digital Library
COG validation: SINBAD Benchmark Problems
We validated COG, a 3D Monte Carlo radiation transport code, against experimental data and MNCP4C simulations from the Shielding Integral Benchmark Archive Database (SINBAD) compiled by RSICC. We modeled three experiments: the Osaka Nickel and Aluminum sphere experiments conducted at the OKTAVIAN facility, and the liquid oxygen experiment conducted at the FNS facility. COG results are in good agreement with experimental data and generally within a few % of MCNP results. There are several possible sources of discrepancy between MCNP and COG results: (1) the cross-section database versions are different, MCNP uses ENDFB VI 1.1 while COG uses ENDFB VIR7, (2) the code implementations are different, and (3) the models may differ slightly. We also limited the use of variance reduction methods when running the COG version of the problems.
Date:
February 23, 2004
Creator:
Lent, E M; Sale, K E; Buck, R M & Descalle, M
Object Type:
Report
System:
The UNT Digital Library
Synthesis of Novel Extended Phases of Molecular Solids at High Pressures and Temperatures
This study is for in-situ investigation of chemical bonding and molecular structure of low z-elements and simple molecular solids at high pressures and temperatures using 3rd-generation synchrotron x-ray diffraction. To understand the contribution of the empty d-electron orbital of Mg in relation to the formation of molecular solids like MgO, which is one of the important Earth lower mantle materials and MgB{sub 2}, which has recently been the focus of intense superconducting material research, we have performed double-sided laser heating experiments using a diamond anvil cell (DAC). Understanding the structural stability and the formation of the above Mg-compounds requires studying Mg itself as well as the relevant compounds. BL10XU at the Spring-8 was used to study phase stability and make accurate equation of state (EOS) determinations of Mg coupled with external heating and the double-sided laser heating technique. Monochromatic x-ray at 30 keV (0.4135 {angstrom}) was focused to about 40 {micro}m at the sample and the diffracted x-ray were recorded using a high-resolution image plate (3000 x 3000 pixels with a 0.1 mm resolution per pixel). EOS parameters for hcp and bcc Mg were determined by fitting to a Birch-Murnaghan equation. An isothermal compression of Mg at 300 K up …
Date:
March 30, 2004
Creator:
Yoo, C; Evans, W & Cynn, H
Object Type:
Report
System:
The UNT Digital Library
Insights into the Dynamic Response of Tunnels in Jointed Rocks
Tunnels in jointed rocks can be subjected to severe dynamic loads because of rock bursts, coal bumps, and large earthquakes. A series of 3-dimensional simulations was performed, based on discrete element analysis to gain insights into the parameters that influence the response of such tunnels. The simulations looked at the effect of joint set orientation, the effect of joint spacing, the effect of pulse shape for a given displacement, and the influence of using rigid versus deformable blocks in the analyses. The results of this modeling were also compared to field evidence of dynamic tunnel failures. This comparison reinforced the notion that 3-dimensional discrete element analysis can capture very well the kinematics of structures in jointed rock under dynamic loading.
Date:
November 1, 2004
Creator:
Heuze, F E
Object Type:
Article
System:
The UNT Digital Library
Small Wind Electric Systems: An Idaho Consumer's Guide (Revised)
Small Wind Electric Systems: An Idaho Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and their economics. Topics discussed in the guide include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a regional wind resource map and a list of incentives and contacts for more information.
Date:
August 1, 2004
Creator:
unknown
Object Type:
Text
System:
The UNT Digital Library
The 1997/98 El Nino: A Test for Climate Models
Version 3 of the Hadley Centre Atmospheric Model (HadAM3) has been used to demonstrate one means of comparing a general circulation model with observations for a specific climate perturbation, namely the strong 1997/98 El Nino. This event was characterized by the collapse of the tropical Pacific's Walker circulation, caused by the lack of a zonal sea surface temperature gradient during the El Nino. Relative to normal years, cloud altitudes were lower in the western portion of the Pacific and higher in the eastern portion. HadAM3 likewise produced the observed collapse of the Walker circulation, and it did a reasonable job of reproducing the west/east cloud structure changes. This illustrates that the 1997/98 El Nino serves as a useful means of testing cloud-climate interactions in climate models.
Date:
March 5, 2004
Creator:
Lu, R; Dong, B; Cess, R D & Potter, G L
Object Type:
Article
System:
The UNT Digital Library
Toward understanding environmental effects in SDSS clusters
We find clusters and superclusters of galaxies using the Data Release 1 of the Sloan Digital Sky Survey. We determine the luminosity function of clusters and find that clusters in a high-density environment have a luminosity a factor of {approx}5 higher than in a low-density environment. We also study clusters and superclusters in numerical simulations. Simulated clusters in a high-density environment are also more massive than those in a low-density environment. Comparison of the density distribution at various epochs in simulations shows that in large low-density regions (voids) dynamical evolution is very slow and stops at an early epoch. In contrast, in large regions of higher density (superclusters) dynamical evolution starts early and continues until the present; here particles cluster early, and by merging of smaller groups very rich systems of galaxies form.
Date:
November 1, 2004
Creator:
Einasto, Jaan; Tago, E.; Einasto, M.; Saar, E.; Suhhonenko, I.; Heinamaki, P. et al.
Object Type:
Article
System:
The UNT Digital Library
Manifestation of the Color Glass Condensate in Particle Production at RHIC.
In this paper we discuss the experimental signatures of the new form of nuclear matter--the Color Glass Condensate (CGC) in particle production at RHIC. We show that predictions for particle production in p(d)A and AA collisions derived from these properties are in agreement with data collected at RHIC.
Date:
July 26, 2004
Creator:
Tuchin, K.
Object Type:
Article
System:
The UNT Digital Library
EVALUATING ENVIRONMENTAL DECISION SUPPORT TOOLS.
Effective contaminated land management requires a number of decisions addressing a suite of technical, economic, and social concerns. These concerns include human health risks, ecological risks, economic costs, technical feasibility of proposed remedial actions, and the value society places on clean-up and re-use of formerly contaminated lands. Decision making, in the face of uncertainty and multiple and often conflicting objectives, is a vital and challenging role in environmental management that affects a significant economic activity. Although each environmental remediation problem is unique and requires a site-specific analysis, many of the key decisions are similar in structure. This has led many to attempt to develop standard approaches. As part of the standardization process, attempts have been made to codify specialist expertise into decision support tools. This activity is intended to facilitate reproducible and transparent decision making. The process of codifying procedures has also been found to be a useful activity for establishing and rationalizing management processes. This study will have two primary objectives. The first is to develop taxonomy for Decision Support Tools (DST) to provide a framework for understanding the different tools and what they are designed to address in the context of environmental remediation problems. The taxonomy will have …
Date:
October 1, 2004
Creator:
SULLIVAN, T.
Object Type:
Report
System:
The UNT Digital Library
Seismic Response Prediction of Nupec's Field Model Tests of Npp Structures With Adjacent Building Effect.
As part of a verification test program for seismic analysis computer codes for Nuclear Power Plant (NPP) structures, the Nuclear Power Engineering Corporation (NUPEC) of Japan has conducted a series of field model tests to address the dynamic cross interaction (DCI) effect on the seismic response of NPP structures built in close proximity to each other. The program provided field data to study the methodologies commonly associated with seismic analyses considering the DCI effect. As part of a collaborative program between the United States and Japan on seismic issues related to NPP applications, the U.S. Nuclear Regulatory Commission sponsored a program at Brookhaven National Laboratory (BNL) to perform independent seismic analyses which applied common analysis procedures to predict the building response to recorded earthquake events for the test models with DCI effect. In this study, two large-scale DCI test model configurations were analyzed: (1) twin reactor buildings in close proximity and (2) adjacent reactor and turbine buildings. This paper describes the NUPEC DCI test models, the BNL analysis using the SASSI 2000 program, and comparisons between the BNL analysis results and recorded field responses. To account for large variability in the soil properties, the conventional approach of computing seismic responses …
Date:
March 4, 2004
Creator:
Xu, J.; Hofmayer, C. & Ali, S.
Object Type:
Article
System:
The UNT Digital Library
Analysis and Comparison of Test Results from the Small Wind Research Turbine Test Project: Preprint
Most small wind turbines furl (yaw or tilt out of the wind) as a means of limiting power and rotor speeds in high winds. The Small Wind Research Turbine (SWRT) testing project was initiated in 2003 with the goal of better characterizing both small wind turbine loads (including thrust) and dynamic behavior, specifically as they relate to furling. The main purpose of the testing was to produce high-quality data sets for model development and validation and to help the wind industry further their understanding of small wind turbine behavior. Testing was conducted on a modified Bergey Excel 10-kW wind turbine. A special shaft sensor was designed to measure shaft loads including thrust, torque, and shaft bending. Analysis of 10-minute mean data showed a strong correlation between furling and center of thrust location, as calculated from the shaft-bending and thrust measurements. Data were collected for three different turbine configurations that included a change in the lateral furling offset and the blades. An analysis of inflow conditions indicated that organized atmospheric turbulence had some impact on furling.
Date:
November 1, 2004
Creator:
Corbus, D. & Prascher, D.
Object Type:
Article
System:
The UNT Digital Library
A Tightly Coupled Particle-Fluid Model for DNA-Laden Flows in Complex Microscale Geometries
We present a stable and convergent method for the computation of flows of DNA-laden fluids in microchannels with complex geometry. The numerical strategy combines a ball-rod model representation for polymers tightly coupled with a projection method for incompressible viscous flow. We use Cartesian grid embedded boundary methods to discretize the fluid equations in the presence of complex domain boundaries. A sample calculation is presented showing flow through a packed array microchannel in 2D.
Date:
November 18, 2004
Creator:
Trebotich, D; Miller, G H; Colella, P; Graves, D T; Martin, D F & Schwartz, P O
Object Type:
Article
System:
The UNT Digital Library
Rapid Qualitative Risk Assessment for Contaminant Leakage From Coal Seams During Underground Coal Gasification and CO2 Injection
One of the major risks associated with underground coal gasification is contamination of local aquifers with a variety of toxic compounds. It is likely that the rate, volume, extent, and concentrations of contaminant plumes will depend on the local permeability field near the point of gasification. This field depends heavily on the geological history of stratigraphic deposition and the specifics of stratigraphic succession. Some coals are thick and isolated, whereas others are thinner and more regionally expressed. Some coals are overlain by impermeable units, such as marine or lacustrine shales, whereas others are overlain by permeable zones associated with deltaic or fluvial successions. Rapid stratigraphic characterization of the succession provides first order information as to the general risk of contaminant escape, which provides a means of ranking coal contaminant risks by their depositional context. This risk categorization could also be used for ranking the relative risk of CO{sub 2} escape from injected coal seams. Further work is needed to verify accuracy and provide some quantification of risks.
Date:
July 2, 2004
Creator:
Friedmann, S J
Object Type:
Report
System:
The UNT Digital Library
Measurement of Electron Impact Collisional Excitation Cross Sections of Ni to Ga-Like Gold
None
Date:
August 24, 2004
Creator:
May, M.; Beiersdorfer, P.; Jordan, N.; Scofield, J.; Reed, K.; Hansen, S. et al.
Object Type:
Article
System:
The UNT Digital Library
Theoretical study of the electronic states of Nb4, Nb5 clusters and their anions (Nb4?, Nb5?)
Geometries and energy separations of the various low-lying electronic states of Nb{sub n} and Nb{sub n}{sup -} (n = 4, 5) clusters with various structural arrangements have been investigated. The complete active space multi-configuration self-consistent field (CASMCSCF) method followed by multi-reference singles and doubles configuration interaction (MRSDCI) calculations that included up to 52 million configuration spin functions have been used to compute several electronic states of these clusters. The ground states of both Nb{sub 4} ({sup 1}A', pyramidal) and Nb{sub 4}{sup -} ({sup 2}B{sub 3g}, rhombus) are low-spin states at the MRSDCI level. The ground state of Nb{sub 5} cluster is a doublet with a distorted trigonal bipyramid (DTB) structure. The anionic cluster of Nb{sub 5} has two competitive ground states with singlet and triplet multiplicities (DTB). The low-lying electronic states of these clusters have been found to be distorted due to Jahn-Teller effect. On the basis of the energy separations of our computed electronic states of Nb{sub 4} and Nb{sub 5}, we have assigned the observed photoelectron spectrum of Nb{sub n}{sup -}(n = 4, 5) clusters. We have also compared our MRSDCI results with density functional calculations. The electron affinity, ionization potential, dissociation and atomization energies of Nb{sub 4} …
Date:
May 6, 2004
Creator:
Balasubramanian, K & Majumdar, D
Object Type:
Article
System:
The UNT Digital Library
ESTIMATES FOR RELEASE OF RADIONUCLIDES FROM POTENTIALLY CONTAMINATED CONCRETE AT THE HADDAM NECK NUCLEAR PLANT.
Decommissioning of the Haddam Neck Nuclear Power Plant operated by Connecticut Yankee is in progress. Figure 1 shows a schematic of the Containment Building and Spent Fuel Pool (SFP) Building. Consideration is being given to leaving some subsurface concrete from the Containment, Spent Fuel and certain other buildings in place following NRC license termination. Characterization data of most of these structures show small amounts of residual contamination. The In-Core Sump area of the Containment Building has shown elevated levels of tritium, Co-60, Fe-55, and Eu-152 and lesser quantities of other radionuclides due to neutron activation of the concrete in this area. This analysis is provided to determine levels of residual contamination that will not cause releases to the groundwater in excess of the acceptable dose limits. The objective is to calculate a conservative relationship between the radionuclide concentration of subsurface concrete and the maximum groundwater concentration (pCi/L) for the concrete that may remain following license termination at Connecticut Yankee.
Date:
September 15, 2004
Creator:
SULLIVAN, T.
Object Type:
Report
System:
The UNT Digital Library
Pore Fluid Effects on Shear Modulus for Sandstones with Soft Anisotropy
None
Date:
March 25, 2004
Creator:
Berger, E. L.
Object Type:
Article
System:
The UNT Digital Library
Formulation of the Linear Response Theory in Relativistic LAPW Method. Calculation of Forces in Alpha-Pu
Linear-response (LR) theory in combination with the first-principles band structure codes allows to calculate phonons in an efficient way. In this report a formalism which enables us to apply LR theory within an all-electron framework utilizing the relativistic full-potential linearized augmented plane-wave (RFLAPW) method is presented. As first part, the equations for the calculations of the atomic forces are given and they are used for the calculation of forces in {alpha}-Pu. As a second step, a complete set of formulaes for the dynamic matrices calculation is presented.
Date:
January 8, 2004
Creator:
Kutepov, A L
Object Type:
Report
System:
The UNT Digital Library
Field Verification Project for Small Wind Turbines, Quarterly Report, October-December 2001, 4th Quarter, Issue No.7
This newsletter provides a brief overview of the Field Verification Project for Small Wind Turbines conducted at the NWTC, along with a description of activities and case studies of projects.
Date:
December 1, 2004
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library