Demonstration of an improved subfilter stress closure for WRF (open access)

Demonstration of an improved subfilter stress closure for WRF

None
Date: September 5, 2007
Creator: Mirocha, J D; Lundquist, J K; Chow, F K & Lundquist, K A
Object Type: Article
System: The UNT Digital Library
A density functional theory study of the oxidation of methanol to formaldehyde over vanadia supported on silica, titania, and zirconia (open access)

A density functional theory study of the oxidation of methanol to formaldehyde over vanadia supported on silica, titania, and zirconia

Density functional theory was used to investigate the mechanism and kinetics of methanol oxidation to formaldehyde over vanadia supported on silica, titania, and zirconia. The catalytically active site was modeled as an isolated VO{sub 4} unit attached to the support. The calculated geometry and vibrational frequencies of the active site are in good agreement with experimental measurements both for model compounds and oxide-supported vanadia. Methanol adsorption is found to occur preferentially with the rupture of a V-O-M bond (M = Si, Ti, Zr) and with preferential attachment of a methoxy group to V. The vibrational frequencies of the methoxy group are in good agreement with those observed experimentally as are the calculated isobars. The formation of formaldehyde is assumed to occur via the transfer of an H atom of a methoxy group to the O atom of the V=O group. The activation energy for this process is found to be in the range of 199-214 kJ/mol and apparent activation energies for the overall oxidation of methanol to formaldehyde are predicted to lie in the range of 112-123 kJ/mol, which is significantly higher than that found experimentally. Moreover, the predicted turnover frequency (TOF) for methanol oxidation is found to be essentially …
Date: September 5, 2002
Creator: Khaliullin, Rustam Z. & Bell, Alexis T.
Object Type: Article
System: The UNT Digital Library
Design analysis supporting 101-SY Water Decon System (open access)

Design analysis supporting 101-SY Water Decon System

This document contains the results of stress analysis and component sizing for the 101-SY mitigation pump, Water Decon System. Calculations included are a stress analysis of the High Pressure Manifold, the threaded connection on the Yoke Water Connector and a sizing of an air receiver tank.
Date: September 5, 1995
Creator: Cleveland, K.J.
Object Type: Report
System: The UNT Digital Library
The design and construction of a gradient solenoid for the high powered RF cavity experiment for the muon collider (open access)

The design and construction of a gradient solenoid for the high powered RF cavity experiment for the muon collider

This report describes the construction and test of a split solenoid that has a warm bore of 440 mm and a cryostat length of 1088 mm. (A 750 mm section contains the magnetic field.) When the coils are hooked so the fields are additive, the central induction is 5.0 T at its design current. When the coils are hooked so that the fields are in opposition, the induction at the center of the solenoid is zero and the peak induction on the solenoid axis is {+-}3.7 T. The on-axis induction gradient is 25 T per meter when the coils are hooked in opposition. When the coils are operated at their design currents in opposition, the force pushing the two coils apart is about 3 MN. The force pushing the coils apart is carried by the aluminum coil mandrel and a solid aluminum sheath outside of the superconducting winding. The coil was wound as a wet lay-up coil using alumina filled epoxy (Stycast). A layer of hard aluminum wire wound on the outside of the superconducting coil carries some of the hoop forces and limits the strain so that training does not occur. At design current, at both polarities, the peak …
Date: September 5, 1999
Creator: Green, M. A.; Chen, J. Y. & Wang, S. T.
Object Type: Article
System: The UNT Digital Library
Design and Test of Advanced Multi-Layer Dielectric Gratings for High Energy Petawatt (open access)

Design and Test of Advanced Multi-Layer Dielectric Gratings for High Energy Petawatt

In this paper we discuss recent work on the development of high damage threshold, high efficiency MLD (multilayer dielectric) diffraction gratings for use in high energy, petawatt laser systems. This effort involves a close integration between modeling, fabrication, and testing. The modeling work is used to identify grating designs that satisfy the constraints of high efficiency (>94%) and low field enhancement which is a necessary condition for high damage threshold. Subscale MLD gratings for test are being fabricated in an advanced ion-etch machine we have recently built. The testing effort is being conducted in a dedicated laboratory. The laser beam used to test the samples is based on an OPCPA (optical parametric chirped-pulse amplifier) and a compressor that can provide pulse energies up to 50mJ with pulse lengths variable from 0.3-20 ps. This test station is equipped with diagnostics to fully characterize both the spatial and temporal characteristics of the test beam at the plane of the sample. Initial results have demonstrated a dependence of damage threshold on incident angle that is in good agreement with the field enhancement calculations. We have demonstrated a grating design with a damage threshold of 3J/cm{sup 2} and are investigating manufacturability and reproducibility issues …
Date: September 5, 2003
Creator: Molander, W.; Komashko, A.; Britten, J.; Jones, L.; Brown, C.; Caird, J. et al.
Object Type: Article
System: The UNT Digital Library
Design & Fabrication of a High-Voltage Photovoltaic Cell (open access)

Design & Fabrication of a High-Voltage Photovoltaic Cell

Silicon photovoltaic (PV) cells are alternative energy sources that are important in sustainable power generation. Currently, applications of PV cells are limited by the low output voltage and somewhat low efficiency of such devices. In light of this fact, this project investigates the possibility of fabricating high-voltage PV cells on float-zone silicon wafers having output voltages ranging from 50 V to 2000 V. Three designs with different geometries of diffusion layers were simulated and compared in terms of metal coverage, recombination, built-in potential, and conduction current density. One design was then chosen and optimized to be implemented in the final device design. The results of the simulation serve as a feasibility test for the design concept and provide supportive evidence of the effectiveness of silicon PV cells as high-voltage power supplies.
Date: September 5, 2012
Creator: Felder, Jennifer & /SLAC, /North Carolina State U.
Object Type: Report
System: The UNT Digital Library
DEVELOPMENT PRACTICES FOR OPTIMIZED MEOR IN SHALLOW HEAVY OIL RESERVOIRS (open access)

DEVELOPMENT PRACTICES FOR OPTIMIZED MEOR IN SHALLOW HEAVY OIL RESERVOIRS

The objective of this research project is to demonstrate an economically viable and sustainable method of producing shallow heavy oil reserves in western Missouri and southeastern Kansas, using an integrated approach including surface geochemical surveys, conventional MEOR treatments, horizontal fracturing in vertical wells, electrical resistivity tomography (ERT), and reservoir simulation to optimize the recovery process. The objective also includes transferring the knowledge gained from the project to other local landowners, to demonstrate how they may identify and develop their own heavy oil resources with minimal capital investment. Tasks completed in the first six-month period include soil sampling, geochemical analysis, construction of ERT arrays, collection of background ERT surveys, and analysis of core samples to develop a geomechanical model for designing the hydraulic fracturing treatment. Five wells were to be drilled in phase I. However, weather and funding delays resulted in drilling shifting to the second phase of the project. Work performed to date demonstrates that surface geochemical methods can be used to differentiate between productive and non-productive areas of the Warner Sand and that ERT can be used to successfully image through the Warner Sand.
Date: September 5, 2003
Creator: Dunn-Norman, Shari
Object Type: Report
System: The UNT Digital Library
DISCO: An object-oriented system for music composition and sound design (open access)

DISCO: An object-oriented system for music composition and sound design

This paper describes an object-oriented approach to music composition and sound design. The approach unifies the processes of music making and instrument building by using similar logic, objects, and procedures. The composition modules use an abstract representation of musical data, which can be easily mapped onto different synthesis languages or a traditionally notated score. An abstract base class is used to derive classes on different time scales. Objects can be related to act across time scales, as well as across an entire piece, and relationships between similar objects can replicate traditional music operations or introduce new ones. The DISCO (Digital Instrument for Sonification and Composition) system is an open-ended work in progress.
Date: September 5, 2000
Creator: Kaper, H. G.; Tipei, S. & Wright, J. M.
Object Type: Article
System: The UNT Digital Library
Dispersion and interbunch energy variation for an E sup + E sup minus linear collider (open access)

Dispersion and interbunch energy variation for an E sup + E sup minus linear collider

Recent studies concerning optimization parameters for e{sup +}e{sup {minus}} super linear colliders use multiple particle bunches for each rf pulse to increase the luminosity and overall efficiency. Requirements for final focusing of the beams severely restrict the bunch to bunch energy variation during the rf pulse. To accurately determine the accelerating fields and energy variation, the dispersion related transient behavior of the rf drive pulse must be considered. A numerical study of dispersion effects on several different accelerating structures is presented.
Date: September 5, 1990
Creator: Houck, T.L.
Object Type: Article
System: The UNT Digital Library
Douglas United Nuclear, Inc. Report of the working committee to the Fuel Element Development Committee for activities associated with the small and K Hanford Reactors (open access)

Douglas United Nuclear, Inc. Report of the working committee to the Fuel Element Development Committee for activities associated with the small and K Hanford Reactors

Currently the B, C, KE and KW reactors are in operation. The B and C reactors are operating to produce 12% Pu-240 in both the E metal (0.95) and natural loadings. Some columns will be taken to 15% Pu 240 on a test basis. Production of 12% Pu-240 will result in exposures of 1400 MWD/ton on natural metal and 2,000 MWD/Ton on E metal. Currently exposures are such that 10 1/2% Pu-240 has been achieved. Some control problems and temperature cycling have been encountered with this mode of operation. Both K reactors are on enriched-depleted loads. The depleted metal is scheduled for irradiation to produce 27-30% Pu-240 (about 3,000 MWD/Ton; 15 months residence) and is currently at 30% of goal. The E metal drivers (0.95) will be discharged at weapons grade Pu exposures. The relatively small quantity of natural uranium in the K reactors will be exposed to produce 12% Pu-240.
Date: September 5, 1967
Creator: Stringer, J. T.
Object Type: Report
System: The UNT Digital Library
Dynamic Characterizations of an 8-frame Half-Strip High-speed X-ray Microchannel Plate Imager (open access)

Dynamic Characterizations of an 8-frame Half-Strip High-speed X-ray Microchannel Plate Imager

High-speed microchannel plate (MCP)–based imagers are critical detectors for x-ray diagnostics employed on Z-experiments at Sandia National Laboratories (SNL) to measure time-resolved x-ray spectra and to image dynamic hohlraums. A multiframe design using eight half strips in one imager permits recordings of radiation events in discrete temporal snapshots to yield a time-evolved movie. We present data using various facilities to characterize the performance of this design. These characterization studies include DC and pulsed-voltage biased measurements in both saturated and linear operational regimes using an intense, short-pulsed UV laser. Electrical probe measurements taken to characterize the shape of the HV pulse propagating across the strips help to corroborate the spatial gain dependence.
Date: September 5, 2008
Creator: Ken Moy, Ming Wu, Craig Kruschwitz, Aric Tibbits, Matt Griffin, Greg Rochau
Object Type: Article
System: The UNT Digital Library
Dynamic Volume Holography and Optical Information Processing by Raman Scattering (open access)

Dynamic Volume Holography and Optical Information Processing by Raman Scattering

A method of producing holograms of three-dimensional optical pulses is proposed. It is shown that both the amplitude and the phase profile of three-dimensional optical pulse can be stored in dynamic perturbations of a Raman medium, such as plasma. By employing Raman scattering in a nonlinear medium, information carried by a laser pulse can be captured in the form of a slowly propagating low-frequency wave that persists for a time large compared with the pulse duration. If such a hologram is then probed with a short laser pulse, the information stored in the medium can be retrieved in a second scattered electromagnetic wave. The recording and retrieving processes can conserve robustly the pulse shape, thus enabling the recording and retrieving with fidelity of information stored in optical signals. While storing or reading the pulse structure, the optical information can be processed as an analogue or digital signal, which allows simultaneous transformation of three-dimensional continuous images or computing discrete arrays of binary data. By adjusting the phase fronts of the reference pulses, one can also perform focusing, redirecting, and other types of transformation of the output pulses.
Date: September 5, 2002
Creator: Dodin, I. Y. & Fisch, N. J.
Object Type: Report
System: The UNT Digital Library
DYNSYL: a general-purpose dynamic simulator for chemical processes (open access)

DYNSYL: a general-purpose dynamic simulator for chemical processes

Lawrence Livermore Laboratory is conducting a safeguards program for the Nuclear Regulatory Commission. The goal of the Material Control Project of this program is to evaluate material control and accounting (MCA) methods in plants that handle special nuclear material (SNM). To this end we designed and implemented the dynamic chemical plant simulation program DYNSYL. This program can be used to generate process data or to provide estimates of process performance; it simulates both steady-state and dynamic behavior. The MCA methods that may have to be evaluated range from sophisticated on-line material trackers such as Kalman filter estimators, to relatively simple material balance procedures. This report describes the overall structure of DYNSYL and includes some example problems. The code is still in the experimental stage and revision is continuing.
Date: September 5, 1978
Creator: Patterson, G.K. & Rozsa, R.B.
Object Type: Report
System: The UNT Digital Library
Effect of SOFC Interconnect-Coating Interactions on Coating Properties and Performance (open access)

Effect of SOFC Interconnect-Coating Interactions on Coating Properties and Performance

The high operating temperature of solid oxide fuel cells (SOFCs) provides good fuel flexibility which expands potential applications, but also creates materials challenges. One such challenge is the interconnect material, which was the focus of this project. In particular, the objective of the project was to understand the interaction between the interconnect alloy and ceramic coatings which are needed to minimize chromium volatilization and the associated chromium poisoning of the SOFC cathode. This project focused on coatings based on manganese cobalt oxide spinel phases (Mn,Co)3O4, which have been shown to be effective as coatings for ferritic stainless steel alloys. Analysis of diffusion couples was used to develop a model to describe the interaction between (Mn,Co)3O4 and Cr2O3 in which a two-layer reaction zone is formed. Both layers form the spinel structure, but the concentration gradients at the interface appear like a two-phase boundary suggesting that a miscibility gap is present in the spinel solid solution. A high-chromium spinel layer forms in contact with Cr2O3 and grows by diffusion of manganese and cobalt from the coating material to the Cr2O3. The effect of coating composition, including the addition of dopants, was evaluated and indicated that the reaction rate could be decreased …
Date: September 5, 2012
Creator: Fergus, Jeffrey W.
Object Type: Report
System: The UNT Digital Library
The effects of selenium on glutathione peroxidase activity and radioprotection in mammalian cells (open access)

The effects of selenium on glutathione peroxidase activity and radioprotection in mammalian cells

The media of representative mammalian cell lines were supplemented with low levels of selenium in the form of sodium selenite in order to investigate the effects of selenium on mammalian cells. Following incubation in 30 nM sodium selenite, these cells were assayed for changes in glutathione peroxidase (GPx) activity. The cells examined included NIH 3T3 mouse fibroblasts, PC12 rat sympathetic precursor cells, SupT-1 human lymphocytes, MCF-7{sup adr} human breast carcinoma cells and AA8 Chinese hamster ovary cells. Selenium supplementation resulted in a marginal increase in GPx activity for the NIH 3T3, MCF-7{sup adr} and Supt-1 cells but stimulated GPx activity approximately 5-fold in PC12 and AA8 cells. AA8 cells were selected to evaluate whether selenium supplementation was radioprotective against {sup 60}cobalt gamma irradiation. Protection against radiation-induced mutation was measured by evaluating mutation frequency at the hprt locus. In this assay, preincubation of AA8 CHO cells significantly protected these cells from exposure to 8 Gy.
Date: September 5, 1995
Creator: Diamond, A. M.; Murray, J. L.; Dale, P.; Tritz, R. & Grdina, D. J.
Object Type: Report
System: The UNT Digital Library
The Effects of Void Shape on the Mechanical Properties of Rock (open access)

The Effects of Void Shape on the Mechanical Properties of Rock

The bonded-particle model for rock (Potyondy and Cundall, 2004) represents rock by a dense packing of non-uniform-sized circular or spherical particles that are bonded together at their contact points and whose mechanical behavior is simulated by the distinct-element method using the two- and three-dimensional programs PFC2D and PFC3D. A bonded-particle model of lithophysal tuff has been used to study the effect of lithophysae (hollow, bubble-like voids) on the mechanical properties (Young's modulus and unconfined compressive strength) of this rock, and to quantify the variability of these properties. The model reproduces the failure mechanisms observed in the laboratory and exhibits a reduction of strength and modulus with increasing lithophysal volume fraction. The effect of void shape on mechanical properties is studied by inserting randomly distributed voids of simple shape (circle, triangle and star) and by inserting voids corresponding with lithophysal cavities identified in panel maps of the walls of a tunnel through this material. These studies address tunnel-stability issues associated with mechanical degradation of planned emplacement drifts at Yucca Mountain, which is the designated site for the proposed US high-level nuclear waste repository.
Date: September 5, 2006
Creator: Potyondy, D.O.
Object Type: Report
System: The UNT Digital Library
Employee Handbook (open access)

Employee Handbook

Welcome to Berkeley Lab. You are joining or are already a part of a laboratory with a sterling tradition of scientific achievement, including eleven Nobel Laureates and thirteen National Medal of Science winners. No matter what job you do, you make Berkeley Lab the outstanding organization that it is. Without your hard work and dedication, we could not achieve all that we have. We value you and thank you for choosing to be part of our community. This Employee Handbook is designed to help you navigate the Lab. With over 3,000 employees, an additional 3,000 guests visiting from countries around the world, a 200-acre campus and many policies and procedures, learning all the ins and outs may seem overwhelming, especially if you're a new employee. However, even if you have been here for a while, this Handbook should be a useful reference tool. It is meant to serve as a guide, highlighting and summarizing what you need to know and informing you where you can go for more detailed information. The general information provided in this Handbook serves only as a brief description of many of the Lab's policies. Policies, procedures and information are found in the Lab's Regulations and …
Date: September 5, 2008
Creator: Bello, Madelyn
Object Type: Report
System: The UNT Digital Library
The Enemy Below - The Global Diffusion of Submarines and Related Technology (open access)

The Enemy Below - The Global Diffusion of Submarines and Related Technology

The end of the Cold War seemed to create a more peaceful international environment. September 11 reminded us of the dangers of complacency. Indeed, even before September 11 US forces had intervened in a number of wars and crises, including Panama, the Persian Gulf War, Somalia, Rwanda, Bosnia, Kosovo, several Taiwan Straits crises, the North Korea nuclear weapons crisis, and most recently Afghanistan. US ability to intervene in remote areas of the world is often dependent on the Navy's ability to project power ashore. As a result, US ability to influence events in crisis situations, especially between or among nuclear powers, may become more difficult along with our ability to conduct littoral warfare. Although the numbers of potentially hostile submarines have declined with the end of the Cold War, US anti-submarine warfare capabilities have also declined. Moreover, foreign submarines and related technologies are likely to diffuse globally. New technologies like Air Independent Propulsion (AIP), improved weapons and sensors will make conventional submarines more dangerous, and the spread of nuclear submarines even to a few more countries raise political, military, environmental, and safety concerns. Submarines are one of the key weapon systems used alone or in combination with other weapon systems …
Date: September 5, 2002
Creator: Weiss, K G
Object Type: Article
System: The UNT Digital Library
Enhanced Oil Recovery by Horizontal Waterflooding (open access)

Enhanced Oil Recovery by Horizontal Waterflooding

Solar energy has become a major alternative for supplying a substantial fraction of the nation's future energy needs. The U.S. Department of Energy (DOE) supports activities ranging from the demonstration of existing technology to research on future possibilities. At Lawrence Berkeley Laboratory (LBL), projects are in progress that span a wide range of activities, with the emphasis on research to extend the scientific basis for solar energy applications, and on preliminary development of new approaches to solar energy conversion. To assess various solar applications, it is important to quantify the solar resource. Special instruments have been developed and are now in use to measure both direct solar radiation and circum-solar radiation, i.e., the radiation from near the sun resulting from the scattering of sunlight by small particles in the atmosphere. These measurements serve to predict the performance of solar designs that use focusing collectors employing mirrors or lenses to concentrate the sunlight. Efforts have continued at a low level to assist DOE in demonstrating existing solar technology by providing the San Francisco Operations Office (SAN) with technical support for its management of commercial-building solar demonstration projects. Also, a hot water and space-heating system has been installed on an LBL building …
Date: September 5, 2005
Creator: Robinowitz, Scott; Dauben, Dwight & Schmeling, June
Object Type: Report
System: The UNT Digital Library
Environmental application of stable xenon and radioxenonmonitoring (open access)

Environmental application of stable xenon and radioxenonmonitoring

Characterization of transuranic waste is needed to makedecisions about waste site remediation. Soil-gas sampling for xenonisotopes can be used to define the locations of spent fuel andtransuranic wastes. Radioxenon in the subsurface is characteristic oftransuranic waste and can be measured with extreme sensitivity usinglarge-volume soilgas samples. Measurements at the Hanford Site showed133Xe and 135Xe levels indicative of 240Pu spontaneous fission. Stablexenon isotopic ratios from fission are distinct from atmospheric xenonbackground. Neutron capture by 135Xe produces an excess of 136Xe inreactor-produced xenon providing a means of distinguishing spent fuelfrom separated transuranic materials.
Date: September 5, 2006
Creator: Dresel, P. Evan; Olsen, Khris B.; Hayes, James C.; McIntyre,Justin I.; Waichler, Scott R.; Milbrath, Brian D. et al.
Object Type: Article
System: The UNT Digital Library
EUVE Observations of Nonmagnetic Cataclysmic Variables (open access)

EUVE Observations of Nonmagnetic Cataclysmic Variables

The authors summarize EUVE's contribution to the study of the boundary layer emission of high accretion-rate nonmagnetic cataclysmic variables, especially the dwarf novae SS Cyg, U Gem, VW Hyi, and OY Car in outburst. They discuss the optical and EUV light curves of dwarf nova outbursts, the quasi-coherent oscillations of the EUV flux of SS Cyg, the EUV spectra of dwarf novae, and the future of EUV observations of cataclysmic variables.
Date: September 5, 2001
Creator: Mauche, C W
Object Type: Article
System: The UNT Digital Library
Experimental Neutrino Physics: Final Report (open access)

Experimental Neutrino Physics: Final Report

Experimental studies of neutrino properties, with particular emphasis on neutrino oscillation, mass and mixing parameters. This research was pursued by means of underground detectors for reactor anti-neutrinos, measuring the flux and energy spectra of the neutrinos. More recent investigations have been aimed and developing detector technologies for a long-baseline neutrino experiment (LBNE) using a neutrino beam from Fermilab.
Date: September 5, 2012
Creator: Lane, Charles E. & Maricic, Jelena
Object Type: Report
System: The UNT Digital Library
Experimental Studies of ICF Indirect-Drive Be and High Density C Candidate Ablators (open access)

Experimental Studies of ICF Indirect-Drive Be and High Density C Candidate Ablators

To validate our modeling of the macroscopic and microscopic hydrodynamic and equation of state response of these candidate ablators to NIC-relevant x-ray drive, a multi-lab experimental program has been verifying the behavior of these new ablators. First, the pressures for onset and termination of melt for both Be and HDC under single or double shock drive has been measured at the Z and Omega facilities. Second, the level and effect of hard x-ray preheat has been quantified in scaled experiments at the Omega facility. Third, a long planar x-ray drive has been developed to check 2D and 3D perturbation growth at the ablation front upon acceleration. The concept has been extended to study growth at and near the ablator-ice interface upon deceleration. In addition, experimental designs for validating the expected low level of perturbation seeding due to possible residual microstructure after melt during first and second shock transit in Be and HDC have been completed. Results so far suggest both Be and HDC can remain ablator choices and have guided pulse shaping designs.
Date: September 5, 2007
Creator: Landen, O. L.; Bradley, D. K.; Braun, D. G.; Smalyuk, V. A.; Hicks, D. G.; Celliers, P. M. et al.
Object Type: Article
System: The UNT Digital Library
Exploratory coprocessing research (open access)

Exploratory coprocessing research

The objectives of this project were to (1) study the scope of the beneficial effects of hydrothermal pretreatment of coal on subsequent conversion, (2) identify and study the chemical or physical causes of this effect, and (3) attempt to elucidate the chemistry responsible for any coal-resid synergisms.
Date: September 5, 1991
Creator: Hirschon, A. S.; Tse, D. S.; Malhotra, R.; McMillen, D. F. & Ross, D. S.
Object Type: Report
System: The UNT Digital Library