Accounting Procedures for Foreign-owned Nuclear Material Located Temporarily in the Russian Federation (open access)

Accounting Procedures for Foreign-owned Nuclear Material Located Temporarily in the Russian Federation

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Date: May 31, 2005
Creator: Pitel, V. A.; Kasumova, L. A. & Babcock, R. A.
Object Type: Article
System: The UNT Digital Library
B physics: first evidence for b_s0 --> phi phi decay and measurements of branching ratio and a_cp for b+ --> phi k+ (open access)

B physics: first evidence for b_s0 --> phi phi decay and measurements of branching ratio and a_cp for b+ --> phi k+

We present the first evidence of charmless decays of the B{sub s}{sup 0} meson, the decay B{sub s}{sup 0} {yields} {phi}{phi}, and a measurement of the Branching Ratio BR(B{sub s}{sup 0} {yields} {phi}{phi}) using 180 pb{sup -1} of data collected by the CDF II experiment at the Fermilab Tevatron collider. In addition, the BR and direct CP asymmetry for the B{sup +} {yields} {phi}K{sup +} decay are measured.
Date: May 31, 2005
Creator: Acosta, D.
Object Type: Report
System: The UNT Digital Library
Bank Upgrade for Sspx at Llnl (open access)

Bank Upgrade for Sspx at Llnl

A new 5kV, 1.5MJ modular capacitor bank has been designed for the Sustained Spheromak Physics Experiment (SSPX) at LLNL. The new bank consists of thirty 4mF capacitors that are independently controlled by light-triggered thyristors. By closing all switches simultaneously, the bank will provide a mega-ampere discharge. The new bank will also allow additional capabilities to SSPX, including higher peak gun current, longer current pulses, and multi-pulse plasma buildup. Experiment results for a single stage prototype will be presented, deliver a single large current spike, or, switches can be triggered in sequence to deliver a longer lower current pulse. Multiple pulses can be created by triggering sections of the modular bank in intervals.
Date: May 31, 2005
Creator: Marchiano, M. M.; Cook, E. G.; Geer, R. W.; Kemptner, R. O.; McLean, H. S.; Martovetsky, N. N. et al.
Object Type: Article
System: The UNT Digital Library
The Barenblatt Turbulent Burst Problem in Kull (open access)

The Barenblatt Turbulent Burst Problem in Kull

Significant changes have recently been made to the way in which explicit diffusion is carried out for the turbulent mix model in Kull. That is, the upwind method of calculating divergences of drift/diffusion velocities has been replaced by a more standard treatment, where diffusion coefficients are averaged to the nodes, multiplied by the gradient of some field, and then the usual divergence of this product is taken. Boundary conditions are handled very differently in these two approaches, and for Rayleigh-Taylor problems, the upwind method leads to non-monotonic density profiles and an incorrect treatment of fluxes at mesh boundaries. The more standard approach to diffusion is also taking advantage of the new, more powerful region definition in Kull which puts buffer zones around the region at material boundaries (external zones) and also at mesh boundaries (external surface zones). This allows for much more control of the fluxes at these boundaries, and also saves considerable computer time and memory, since we can now take gradients and divergences of region based fields (rather than the old approach of creating a mesh based field to store the region quantity, performing the differential operators on the mesh based field, and finally storing the mesh based …
Date: May 31, 2005
Creator: Ulitsky, M
Object Type: Report
System: The UNT Digital Library
Breaking Barriers to Low-Cost Modular Inverter Production & Use (open access)

Breaking Barriers to Low-Cost Modular Inverter Production & Use

The goal of this cost share contract is to advance key technologies to reduce size, weight and cost while enhancing performance and reliability of Modular Inverter Product for Distributed Energy Resources (DER). Efforts address technology development to meet technical needs of DER market protection, isolation, reliability, and quality. Program activities build on SatCon Technology Corporation inverter experience (e.g., AIPM, Starsine, PowerGate) for Photovoltaic, Fuel Cell, Energy Storage applications. Efforts focused four technical areas, Capacitors, Cooling, Voltage Sensing and Control of Parallel Inverters. Capacitor efforts developed a hybrid capacitor approach for conditioning SatCon's AIPM unit supply voltages by incorporating several types and sizes to store energy and filter at high, medium and low frequencies while minimizing parasitics (ESR and ESL). Cooling efforts converted the liquid cooled AIPM module to an air-cooled unit using augmented fin, impingement flow cooling. Voltage sensing efforts successfully modified the existing AIPM sensor board to allow several, application dependent configurations and enabling voltage sensor galvanic isolation. Parallel inverter control efforts realized a reliable technique to control individual inverters, connected in a parallel configuration, without a communication link. Individual inverter currents, AC and DC, were balanced in the paralleled modules by introducing a delay to the individual PWM …
Date: May 31, 2005
Creator: Borowy, Bogdan; Casey, Leo; Foshage, Jerry; Nichols, Steve & Perkinson, Jim
Object Type: Report
System: The UNT Digital Library
Class B0631+519: Last of the Class Lenses (open access)

Class B0631+519: Last of the Class Lenses

We report the discovery of the new gravitational lens system CLASS B0631+519. Imaging with the VLA, MERLIN and the VLBA reveals a doubly-imaged flat-spectrum radio core, a doubly-imaged steep-spectrum radio lobe and possible quadruply-imaged emission from a second lobe. The maximum separation between the lensed images is 1.16 arcsec. High resolution mapping with the VLBA at 5 GHz resolves the most magnified image of the radio core into a number of sub-components spread across approximately 20 mas. No emission from the lensing galaxy or an odd image is detected down to 0.31 mJy (5{sigma}) at 8.4 GHz. Optical and near-infrared imaging with the ACS and NICMOS cameras on the HST show that there are two galaxies along the line of sight to the lensed source, as previously discovered by optical spectroscopy. We find that the foreground galaxy at z=0.0896 is a small irregular, and that the other, at z=0.6196 is a massive elliptical which appears to contribute the majority of the lensing effect. The host galaxy of the lensed source is detected in the HST near-infrared imaging as a set of arcs, which form a nearly complete Einstein ring. Mass modeling using non-parametric techniques can reproduce the near-infrared observations and …
Date: May 31, 2005
Creator: York, Tom; Jackson, N.; Browne, I. W. A.; Koopmans, L. V. E.; McKean, J. P.; Norbury, M. A. et al.
Object Type: Article
System: The UNT Digital Library
Compression Stripping of Flue Gas with Energy Recovery (open access)

Compression Stripping of Flue Gas with Energy Recovery

A method of remediating and recovering energy from combustion products from a fossil fuel power plant having at least one fossil fuel combustion chamber, at least one compressor, at least one turbine, at least one heat exchanger and a source of oxygen. Combustion products including non-condensable gases such as oxygen and nitrogen and condensable vapors such as water vapor and acid gases such as SO<sub>X</sub> and NO<sub>X</sub> and CO<sub>2</sub> and pollutants are produced and energy is recovered during the remediation which recycles combustion products and adds oxygen to support combustion. The temperature and/or pressure of the combustion products are changed by cooling through heat exchange with thermodynamic working fluids in the power generation cycle and/or compressing and/or heating and/or expanding the combustion products to a temperature/pressure combination below the dew point of at least some of the condensable vapors to condense liquid having some acid gases dissolved and/or entrained and/or directly condense acid gas vapors from the combustion products and to entrain and/or dissolve some of the pollutants while recovering sensible and/or latent heat from the combustion products through heat exchange between the combustion products and thermodynamic working fluids and/or cooling fluids used in the power generating cycle. Then the …
Date: May 31, 2005
Creator: Ochs, Thomas L. & O'Connor, William K.
Object Type: Patent
System: The UNT Digital Library
Design and Evaluation of Ionic Liquids as Novel CO2 Absorbents (open access)

Design and Evaluation of Ionic Liquids as Novel CO2 Absorbents

Ionic liquids are a new and exciting class of compound that have the potential to overcome many of the problems associated with current CO{sub 2}-capture techniques. Ionic liquids (ILs) are organic salts that are liquid in their pure state near ambient conditions. ILs are regarded as potentially environmentally-benign solvents due to their immeasurably low vapor pressure, which essentially eliminates the opportunity for solvent release to the atmosphere. The goal of this project is to obtain a fundamental understanding of the solubility of CO{sub 2} and other components present in flue gas in ILs, with the practical objective of tailoring the properties of the liquid to maximize the engineering properties for this process. Our plan is to do this through a combination of synthesis and experimental measurements, molecular simulation and applications development. This third quarterly technical report (Q2 2005) describes the results of our work on this project from 01/01/2005 through the end of the third quarter (03/31/05).
Date: May 31, 2005
Creator: Maginn, Edward J.
Object Type: Report
System: The UNT Digital Library
Determination of the Structure of Vitrified Hydroceramic/CBC Waste Form Glasses Manufactured from DOE Reprocessing Waste (open access)

Determination of the Structure of Vitrified Hydroceramic/CBC Waste Form Glasses Manufactured from DOE Reprocessing Waste

The selection of a glass-making option for the solidification of nuclear waste has dominated DOE waste form programs since the early 1980's. Both West Valley and Savannah River are routinely manufacturing glass logs from the high level waste inventory in tank sludges. However, for some wastes, direct conversion to glass is clearly not the optimum strategy for immobilization. INEEL, for example, has approximately 4400 m{sup 3} of calcined high level waste with an activity that produces approximately 45 watts/m{sup 3}, a rather low concentration of radioactive constituents. For these wastes, there is value in seeking alternatives to glass. An alternative approach has been developed and the efficacy of the process demonstrated that offers a significant savings in both human health and safety exposures and also a lower cost relative to the vitrification option. The alternative approach utilizes the intrinsic chemical reactivity of the highly alkaline waste with the addition of aluminosilicate admixtures in the appropriate proportions to form zeolites. The process is one in which a chemically bonded ceramic is produced. The driving force for reaction is derived from the chemical system itself at very modest temperatures and yet forms predominantly crystalline phases. Because the chemically bonded ceramic requires an …
Date: May 31, 2005
Creator: Scheetz, B.E.; White, W. B.; Chesleigh, M.; Portanova, A. & Olanrewaju, J.
Object Type: Report
System: The UNT Digital Library
Development of the household sample for furnace and boilerlife-cycle cost analysis (open access)

Development of the household sample for furnace and boilerlife-cycle cost analysis

Residential household space heating energy use comprises close to half of all residential energy consumption. Currently, average space heating use by household is 43.9 Mbtu for a year. An average, however, does not reflect regional variation in heating practices, energy costs, or fuel type. Indeed, a national average does not capture regional or consumer group cost impacts from changing efficiency levels of heating equipment. The US Department of Energy sets energy standards for residential appliances in, what is called, a rulemaking process. The residential furnace and boiler efficiency rulemaking process investigates the costs and benefits of possible updates to the current minimum efficiency regulations. Lawrence Berkeley National Laboratory (LBNL) selected the sample used in the residential furnace and boiler efficiency rulemaking from publically available data representing United States residences. The sample represents 107 million households in the country. The data sample provides the household energy consumption and energy price inputs to the life-cycle cost analysis segment of the furnace and boiler rulemaking. This paper describes the choice of criteria to select the sample of houses used in the rulemaking process. The process of data extraction is detailed in the appendices and is easily duplicated. The life-cycle cost is calculated in …
Date: May 31, 2005
Creator: Whitehead, Camilla Dunham; Franco, Victor; Lekov, Alex & Lutz, Jim
Object Type: Report
System: The UNT Digital Library
Electronic Position Sensor for Power Operated Accessory (open access)

Electronic Position Sensor for Power Operated Accessory

An electronic position sensor for use with a power operated vehicle accessory, such as a power liftgate. The position sensor includes an elongated resistive circuit that is mounted such that it is stationary and extends along the path of a track portion of the power operated accessory. The position sensor further includes a contact nub mounted to a link member that moves within the track portion such that the contact nub is slidingly biased against the elongated circuit. As the link member moves under the force of a motor-driven output gear, the contact nub slides along the surface of the resistive circuit, thereby affecting the overall resistance of the circuit. The position sensor uses the overall resistance to provide an electronic position signal to an ECU, wherein the signal is indicative of the absolute position of the power operated accessory. Accordingly, the electronic position sensor is capable of providing an electronic signal that enables the ECU to track the absolute position of the power operated accessory.
Date: May 31, 2005
Creator: Haag, Ronald H. & Chia, Michael I.
Object Type: Text
System: The UNT Digital Library
Evaluation of Alternate Stainless Steel Surface Passivation Methods (open access)

Evaluation of Alternate Stainless Steel Surface Passivation Methods

Stainless steel containers were assembled from parts passivated by four commercial vendors using three passivation methods. The performance of these containers in storing hydrogen isotope mixtures was evaluated by monitoring the composition of initially 50% H{sub 2} 50% D{sub 2} gas with time using mass spectroscopy. Commercial passivation by electropolishing appears to result in surfaces that do not catalyze hydrogen isotope exchange. This method of surface passivation shows promise for tritium service, and should be studied further and considered for use. On the other hand, nitric acid passivation and citric acid passivation may not result in surfaces that do not catalyze the isotope exchange reaction H{sub 2} + D{sub 2} {yields} 2HD. These methods should not be considered to replace the proprietary passivation processes of the two current vendors used at the Savannah River Site Tritium Facility.
Date: May 31, 2005
Creator: Clark, Elliot A.
Object Type: Report
System: The UNT Digital Library
Evaluation of Alternate Surface Passivation Methods (U) (open access)

Evaluation of Alternate Surface Passivation Methods (U)

Stainless steel containers were assembled from parts passivated by four commercial vendors using three passivation methods. The performance of these containers in storing hydrogen isotope mixtures was evaluated by monitoring the composition of initially 50% H{sub 2} 50% D{sub 2} gas with time using mass spectroscopy. Commercial passivation by electropolishing appears to result in surfaces that do not catalyze hydrogen isotope exchange. This method of surface passivation shows promise for tritium service, and should be studied further and considered for use. On the other hand, nitric acid passivation and citric acid passivation may not result in surfaces that do not catalyze the isotope exchange reaction H{sub 2} + D{sub 2} {yields} 2HD. These methods should not be considered to replace the proprietary passivation processes of the two current vendors used at the Savannah River Site Tritium Facility.
Date: May 31, 2005
Creator: Clark, E
Object Type: Report
System: The UNT Digital Library
Experimental Measurement of the Flow Field of Heavy Trucks (open access)

Experimental Measurement of the Flow Field of Heavy Trucks

Flat flaps that enclose the trailer base on the sides and top are known to reduce truck drag and reduce fuel consumption. Such flapped-truck geometries have been studied in laboratory wind tunnels and in field tests. A recent review of wind tunnel data for a variety of truck geometries and flow Reynolds numbers show roughly similar values of peak drag reduction, but differ in the determination of the optimum flap angle. Optimum angles lie in the range 12 degrees-20 degrees, and may be sensitive to Reynolds number and truck geometry. The present field test is undertaken to provide additional estimates of the magnitude of the savings to be expected on a typical truck for five flap angles 10, 13, 16, 19, and 22 degrees. The flaps are constructed from a fiberglass-epoxy-matrix material and are one-quarter of the base width in length (about 61 cm, or 2 feet). They are attached along the rear door hinge lines on either side of the trailer, so that no gap appears at the joint between the flap and the side of the trailer The flap angle is adjusted by means of two aluminum supports. The present test is performed on the NASA Crows Landing …
Date: May 31, 2005
Creator: Browand, Fred & Radovich, Charles
Object Type: Report
System: The UNT Digital Library
Innovative Methodology for Detection of Fracture-Controlled Sweet Spots in the Northern Appalachian Basin (open access)

Innovative Methodology for Detection of Fracture-Controlled Sweet Spots in the Northern Appalachian Basin

The primary goal was to enter Phase 2 by analyzing geophysical logs and sidewall cores from a verification well drilled into the Trenton/Black River section along lineaments. However, the well has not yet been drilled; Phase 2 has therefore not been accomplished. We have switched oil and gas exploration and production companies, and are now in continued negotiations with Fortuna concerning a plan to retrieve 18 m of horizontal core across a gas-charged zone in the Trenton/Black River in central New York State, the ''hottest'' play in the Appalachian Basin. We completed analysis of remote sensing images to determine, by using the weights-of-evidence method, which images and processing techniques result in lineaments that best reflect the fractures found in outcrop. The conclusions do not differ from the preliminary conclusions reported in the previous progress report. These data continue to demonstrate that integration of aeromagnetic and remote sensing lineaments, surface structure, and soil gas and seismic allows us to extrapolate Trenton-Black River trends away from confirmatory seismic lines.
Date: May 31, 2005
Creator: Jacobi, Robert
Object Type: Report
System: The UNT Digital Library
Interwell Connectivity and Diagnosis Using Correlation of Production and Injection Rate Data in Hydrocarbon Production (open access)

Interwell Connectivity and Diagnosis Using Correlation of Production and Injection Rate Data in Hydrocarbon Production

This report details progress on inferring interwell communication from well rate fluctuations. Starting with the procedure of Albertoni and Lake (2003) as a foundation, the goal of the project is to develop further procedures to infer reservoir properties through weights derived from correlations between injection and production rates. A modified method, described in Jensen et al. (2005) and Yousef et al. (2005), and herein referred to as the ''capacitance model'', produces two quantities, {lambda} and {tau}, for each injector-producer well pair. We have focused on the following items: (1) Approaches to integrate {lambda} and {tau} to improve connectivity evaluations. Interpretations have been developed using Lorenz-style and log-log plots to assess heterogeneity. Testing shows the interpretations can identify whether interwell connectivity is controlled by flow through fractures, high-permeability layers, or due to partial completion of wells. Applications to the South Wasson and North Buck Draw Fields show promising results. (2) Optimization of waterflood injection rates using the capacitance model and a power law relationship for watercut to maximize economic return. Initial tests using simulated data and a range of oil prices show the approach is working. (3) Spectral analysis of injection and production data to estimate interwell connectivity and to assess …
Date: May 31, 2005
Creator: Jensen, Jerry L.; Lake, Larry W.; Al-Yousef, Ali; Gentil, Pablo & Demiroren, Nazli
Object Type: Report
System: The UNT Digital Library
The Last of the Finite Loop Amplitudes in QCD (open access)

The Last of the Finite Loop Amplitudes in QCD

We use on-shell recursion relations to determine the one-loop QCD scattering amplitudes with a massless external quark pair and an arbitrary number (n - 2) of positive-helicity gluons. These amplitudes are the last of the unknown infrared- and ultraviolet-finite loop amplitudes of QCD. The recursion relations are similar to ones applied at tree level, but contain new non-trivial features corresponding to poles present for complex momentum arguments but absent for real momenta. We present the relations and the compact solutions to them, valid for all n. We also present compact forms for the previously-computed one-loop n-gluon amplitudes with a single negative helicity and the rest positive helicity.
Date: May 31, 2005
Creator: Bern, Zvi; Dixon, Lance J. & Kosower, David A.
Object Type: Article
System: The UNT Digital Library
A Novel Process to Use Salt Caverns to Receive Ship Borne LNG: Final Report (open access)

A Novel Process to Use Salt Caverns to Receive Ship Borne LNG: Final Report

This cooperative research project validates use of man made salt caverns to receive and store the cargoes of LNG ships in lieu of large liquid LNG tanks. Salt caverns will not tolerate direct injection of LNG because it is a cryogenic liquid, too cold for contact with salt. This research confirmed the technical processes and the economic benefits of pressuring the LNG up to dense phase, warming it to salt compatible temperatures and then directly injecting the dense phase gas into salt caverns for storage. The use of salt caverns to store natural gas sourced from LNG imports, particularly when located offshore, provides a highly secure, large scale and lower cost import facility as an alternative to tank based LNG import terminals. This design can unload a ship in the same time as unloading at a tank based terminal. The Strategic Petroleum Reserve uses man made salt caverns to securely store large quantities of crude oil. Similarly, this project describes a novel application of salt cavern gas storage technologies used for the first time in conjunction with LNG receiving. The energy industry uses man made salt caverns to store an array of gases and liquids but has never used man …
Date: May 31, 2005
Creator: McCall, Michael M.; Bishop, William M.; Krekel, Marcus; Davis, James F. & Scherz, D. Braxton
Object Type: Report
System: The UNT Digital Library
Ocean carbon sequestration by fertilization: An integrated bioeochemical assessment (open access)

Ocean carbon sequestration by fertilization: An integrated bioeochemical assessment

Under this grant, the authors investigated a range of issues associated with the proposal to fertilize the ocean with nutrients (such as iron) in order to increase the export of organic matter from the ocean's near surface waters and consequently increase the uptake of CO{sub 2} from the atmosphere. There are several critical scientific questions that have the potential to be make-or-break issues for this proposed carbon sequestration mechanism: (1) If iron is added to the ocean, will export of organic carbon from the surface actually occur? Clearly, if no export occurs, then there will be no sequestration. (2) if iron fertilization does lead to export of organic carbon from the surface of the ocean, how much CO{sub 2} will actually be removed from the atmosphere? Even if carbon is removed from the surface of the ocean, this does not guarantee that there will be significant removal of CO{sub 2} from the atmosphere, since the CO{sub 2} may be supplied by a realignment of dissolved inorganic carbon within the ocean. (3) What is the time scale of any sequestration that occurs? If sequestered CO{sub 2} returns to the atmosphere on a relatively short time scale, iron fertilization will not contribute …
Date: May 31, 2005
Creator: Gruber, N.; Sarmiento, J.L. & Gnandesikan, A.
Object Type: Report
System: The UNT Digital Library
Optimum model-E-GAMS for Distributed Energy System by Using GAMSMethod (open access)

Optimum model-E-GAMS for Distributed Energy System by Using GAMSMethod

DER-CAM Developed by the Lawrence Berkeley National Laboratory (LBNL), is an optimization tool for DER technology selection. However it can not be simply applied to the Japanese case because of the different climate and the utility tariff. This research aims to develop an optimization tool for distributed energy for Japanese buildings using GAMS, a high-level modeling system for mathematical programming and optimization. This paper describes how we apply and demonstrate the tool to the energy center at Kitakyushu Research city, where has installed a fuel cell and a gas engine. An analysis has also been conducted to see how the utility tarriff and the equipment efficiency can affect the operation of the DER system.
Date: May 31, 2005
Creator: Yang, Yongwen; Gao, Weijun; Ruan, Yingjun; Zhou, Nan; Xuan, Ji & Marnay, Chris
Object Type: Article
System: The UNT Digital Library
Parallel Measurement and Modeling of Transport in the Darht Ii Beamline on Eta Ii (open access)

Parallel Measurement and Modeling of Transport in the Darht Ii Beamline on Eta Ii

To successfully tune the DARHT II transport beamline requires the close coupling of a model of the beam transport and the measurement of the beam observables as the beam conditions and magnet settings are varied. For the ETA II experiment using the DARHT II beamline components this was achieved using the SUICIDE (Simple User Interface Connecting to an Integrated Data Environment) data analysis environment and the FITS (Fully Integrated Transport Simulation) model. The SUICIDE environment has direct access to the experimental beam transport data at acquisition and the FITS predictions of the transport for immediate comparison. The FITS model is coupled into the control system where it can read magnet current settings for real time modeling. We find this integrated coupling is essential for model verification and the successful development of a tuning aid for the efficient convergence on a useable tune. We show the real time comparisons of simulation and experiment and explore the successes and limitations of this close coupled approach.
Date: May 31, 2005
Creator: Chambers, F. W.; Raymond, B. A.; Falabella, S.; Lee, B. S.; Richardson, R. A.; Weir, J. T. et al.
Object Type: Article
System: The UNT Digital Library
Simulation of Hypervelocity Penetration in Limestone (open access)

Simulation of Hypervelocity Penetration in Limestone

A parameter study was performed to examine the (shock) damage obtained with long-rod and spherical mono-material penetrators impacting two varieties of limestone. In all cases, the impacts were assumed to be normal to the plane of the rock and at zero angle of attack (in the case of the rods). Impact velocities ranged to 15 km/s but most calculations were performed at 4 and 6 km/s and the penetrator mass was fixed at 1000 kg. For unlined underground structures, incipient damage was defined to occur when the peak stress, {sigma}{sub pk}, exceeds 1 kb (100 MPa) and the applied impulse per unit area, I{sub pk}, exceeds 1 ktap (1 kb-{micro}s). Severe damage was assumed to occur when {sigma}{sub pk} exceeds 1 kb and I{sub pk} exceeds 1000 ktaps. Using the latter definition it was found that severe damage in hard, non-porous limestone with spherical impactors extended to a depth of 9 m on-axis for an impact velocity of 4 km/s and 12 m at 6 km/s. Cylinders with length-to-diameter (L/D) ratio of 8.75 achieved depth to severe damage of 23 m and 40 m, respectively under the same conditions. For a limestone medium with 2% initial gas porosity, the latter …
Date: May 31, 2005
Creator: Antoun, T; Glenn, L; Walton, O; Goldstein, P; Lomov, I & Liu, B
Object Type: Article
System: The UNT Digital Library
Simulation of penetration into porous geologic media (open access)

Simulation of penetration into porous geologic media

We present a computational study on the penetration of steel projectiles into porous geologic materials. The purpose of the study is to extend the range of applicability of a recently developed constitutive model to simulations involving projectile penetration into geologic media. The constitutive model is non-linear, thermodynamically consistent, and properly invariant under superposed rigid body motions. The equations are valid for large deformations and they are hyperelastic in the sense that the stress tensor is related to a derivative of the Helmholtz free energy. The model uses the mathematical structure of plasticity theory to capture the basic features of the mechanical response of geological materials including the effects of bulking, yielding, damage, porous compaction and loading rate on the material response. The new constitutive model has been successfully used to simulate static laboratory tests under a wide range of triaxial loading conditions, and dynamic spherical wave propagation tests in both dry and saturated geologic media.
Date: May 31, 2005
Creator: Vorobiev, O Y; Liu, B T; Lomov, I N & Antoun, T
Object Type: Article
System: The UNT Digital Library
Sources, Speciation and Mobility of Plutonium and Other Transuranics in the Groundwater at the Savannah River Site (open access)

Sources, Speciation and Mobility of Plutonium and Other Transuranics in the Groundwater at the Savannah River Site

This annual report summarizes work to date on our EMSP project: ?Sources, Speciation and Mobility of Plutonium and Other Transuranics in the Groundwater at the Savannah River Site? (Sept. 2003-Sept. 2006 ABSTRACT Our research focus is to further evaluate the sources and fate of Pu and other transuranics in groundwater at the Savannah River Site (SRS). Our overarching goal is to understand Pu speciation and mobility well enough to support safe remediation, containment and long term stewardship at any site with transuranic wastes and sources. Methods developed under prior funding for the determination Pu isotopes, oxidation state and size fractionation in groundwater are providing the best direct evidence for rejecting or not, hypotheses concerning whether colloids enhance the transport of Pu and other transuranics in groundwater. Survey samples collected in the fall of 2003 from F-area well FSB 78 had a 240/239 Pu atom ratio 7.087 +/-0.048 and reflects the continued presences of decayed 244Cm. In October 2004, we returned to the F-area and completed comprehensive field sampling of 7 wells. Field experiments included 6 different extraction rates at well 92D to test sensitivity to artifacts related to well pumping rates, and an aging experiment to evaluate Pu behavior by …
Date: May 31, 2005
Creator: Buesseler, Ken O.
Object Type: Report
System: The UNT Digital Library