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Acceleration and deceleration phase nonlinear Rayleigh-Taylor growth at spherical interfaces (open access)

Acceleration and deceleration phase nonlinear Rayleigh-Taylor growth at spherical interfaces

The Layzer model for the nonlinear evolution of bubbles in the Rayleigh-Taylor instability has recently been generalized to the case of spherically imploding interfaces [D. S. Clark and M. Tabak, to appear, PRE (2005).]. The spherical case is more relevant to, e.g., inertial confinement fusion or various astrophysical phenomena when the convergence is strong or the perturbation wavelength is comparable to the interface curvature. Here, the model is further extended to the case of bubble growth during the deceleration (stagnation) phase of a spherical implosion and to the growth of spikes during both the acceleration and deceleration phases. Differences in the nonlinear growth rates for both bubbles and spikes are found when compared with planar results. The model predictions are verified by comparison with numerical hydrodynamics simulations.
Date: April 8, 2005
Creator: Clark, D S & Tabak, M
Object Type: Article
System: The UNT Digital Library
Acceleration of Amide Bond Rotation by Encapsulation in the Hydrophobic Interior of a Water-Soluble Supramolecular Assembly (open access)

Acceleration of Amide Bond Rotation by Encapsulation in the Hydrophobic Interior of a Water-Soluble Supramolecular Assembly

The hydrophobic interior cavity of a self-assembled supramolecular assembly exploits the hydrophobic effect for the encapsulation of tertiary amides. Variable temperature 1H NMR experiments reveal that the free energy barrier for rotation around the C-N amide bond is lowered by up to 3.6 kcal/mol upon encapsulation. The hydrophobic cavity of the assembly is able to stabilize the less polar transition state of the amide rotation process. Carbon-13 labeling studies showed that the {sup 13}C NMR carbonyl resonance increases with temperature for the encapsulated amides which suggests that the assembly is able to favor a twisted for of the amide.
Date: April 8, 2008
Creator: Pluth, Michael D.; Bergman, Robert G. & Raymond, Kenneth N.
Object Type: Article
System: The UNT Digital Library
Activation of Air and Utilities in the National Ignition Facility (open access)

Activation of Air and Utilities in the National Ignition Facility

Detailed 3-D modeling of the NIF facility is developed to accurately simulate the radiation environment within the NIF. Neutrons streaming outside the NIF Target Chamber will activate the air present inside the Target Bay and the Ar gas inside the laser tubes. Smaller levels of activity are also generated in the Switchyard air and in the Ar portion of the SY laser beam path. The impact of neutron activation of utilities located inside the Target Bay is analyzed for variety of shot types. The impact of activating TB utilities on dose received by maintenance personnel post-shot is analyzed. The current NIF facility model includes all important features of the Target Chamber, shielding system, and building configuration. Flow of activated air from the Target Bay is controlled by the HVAC system. The amount of activated Target Bay air released through the stack is very small and does not pose significant hazard to personnel or the environment. Activation of Switchyard air is negligible. Activation of Target Bay utilities result in a manageable dose rate environment post high yield (20 MJ) shots. The levels of activation generated in air and utilities during D-D and THD shots are small and do not impact work …
Date: April 8, 2010
Creator: Khater, H; Pohl, B & Brererton, S
Object Type: Article
System: The UNT Digital Library
ADVANCED ABRASION RESISTANT MATERIALS FOR MINING (open access)

ADVANCED ABRASION RESISTANT MATERIALS FOR MINING

The high-density infrared (HDI) transient-liquid coating (TLC) process was successfully developed and demonstrated excellent, enhanced (5 times higher than the current material and process) wear performance for the selected functionally graded material (FGM) coatings under laboratory simulated, in-service conditions. The mating steel component exhibited a wear rate improvement of approximately one and a half (1.5) times. After 8000 cycles of wear testing, the full-scale component testing demonstrated that the coating integrity was still excellent. Little or no spalling was observed to occur.
Date: April 8, 2004
Creator: Ludtka, G. M.
Object Type: Report
System: The UNT Digital Library
Advanced thermal barrier coating system development. Technical progress report, January 1, 1996--March 31, 1996 (open access)

Advanced thermal barrier coating system development. Technical progress report, January 1, 1996--March 31, 1996

Objectives of this program are to provide a thermal barrier coating system with increased temperature capability and improved reliability relative to current state of the art systems. This report describes the bond coat deposition process, manufacturing, and repair.
Date: April 8, 1996
Creator: unknown
Object Type: Report
System: The UNT Digital Library
The Ags High Power Upgrade Plan. (open access)

The Ags High Power Upgrade Plan.

BNL could provide a Megawatt class neutrino beam from the AGS for very long baseline neutrino experiments. We have studied two possible approaches to upgrade the AGS to 1.0 MW beam power. The first is the linac option, comprising a new superconducting linac injector of 1.2 GeV, accelerating 9 x 10{sup 3} proton per pulse in the AGS to 28 GeV at 2.5 Hz. The second option is to extend the existing 200 MeV linac to 400 MeV. ramp the Booster to 2.5 GeV at 6 Hz. add a new 2.5 GeV accumulator ring in the AGS tunnel. and finally ramp the AGS to 28 GeV at 2.5 Hz. Due to the simplicity of the linac approach and minimum interference with the on going research program. the linac option is the preferred one.
Date: April 8, 2002
Creator: Weng, W. T. & Roser, T.
Object Type: Article
System: The UNT Digital Library
Alternative Neutron Detection Testing Summary (open access)

Alternative Neutron Detection Testing Summary

Radiation portal monitors used for interdiction of illicit materials at borders include highly sensitive neutron detection systems. The main reason for having neutron detection capability is to detect fission neutrons from plutonium. Most currently deployed radiation portal monitors (RPMs) use neutron detectors based upon 3He-filled gas proportional counters, which are the most common large area neutron detector. This type of neutron detector is used in the TSA and other RPMs installed in international locations and in the Ludlum and Science Applications International Corporation RPMs deployed primarily for domestic applications. There is a declining supply of 3He in the world and, thus, methods to reduce the use of this gas in RPMs with minimal changes to the current system designs and sensitivity to cargo-borne neutrons are being investigated. Four technologies have been identified as being currently commercially available, potential alternative neutron detectors to replace the use of 3He in RPMs. These technologies are: 1) Boron trifluoride-filled proportional counters, 2) Boron-lined proportional counters, 3) Lithium-loaded glass fibers, and 4) Coated wavelength-shifting plastic fibers. Reported here is a summary of the testing carried out at Pacific Northwest National Laboratory on these technologies to date, as well as measurements on 3He tubes at various …
Date: April 8, 2010
Creator: Kouzes, Richard T.; Ely, James H.; Erikson, Luke E.; Kernan, Warnick J.; Lintereur, Azaree T.; Siciliano, Edward R. et al.
Object Type: Report
System: The UNT Digital Library
Alternatives for sodium-potassium alloy treatment (open access)

Alternatives for sodium-potassium alloy treatment

Sodium-potassium alloy (NaK) is currently treated at the Y-12 Plant by open burning. Due to uncertainties with future permits for this process alternative treatment methods were investigated, revealing that two treatment processes are feasible. One process reacts the NaK with water in a highly concentrated molten caustic solution (sodium and potassium hydroxide). The final waste is a caustic that may be used elsewhere in the plant. This process has two safety concerns: Hot corrosive materials used throughout the process present handling difficulties and the process must be carefully controlled (temperature and water content) to avoid explosive NaK reactions. To avoid these problems a second process was developed that dissolves NaK in a mixture of propylene glycol and water at room temperature. While this process is safer, it generates more waste than the caustic process. The waste may possibly be used as a carbon food source in biological waste treatment operations at the Y-12 Plant. Experiments were conducted to demonstrate both processes, and they showed that both processes are feasible alternatives for NaK treatment. Process flow sheets with mass balances were generated for both processes and compared. While the caustic process generates less waste, the propylene glycol process is safer in …
Date: April 8, 1993
Creator: Takacs, T. J. & Johnson, M. E.
Object Type: Report
System: The UNT Digital Library
An Analysis of Surface and Subsurface Lineaments and Fractures for Oil and Gas Exploration in the Mid-Continent Region (open access)

An Analysis of Surface and Subsurface Lineaments and Fractures for Oil and Gas Exploration in the Mid-Continent Region

An extensive literature search was conducted and geological and mathematical analyses were performed to investigate the significance of using surface lineaments and fractures for delineating oil and gas reservoirs in the Mid-Continent region. Tremendous amount of data were acquired including surface lineaments, surface major fracture zones, surface fracture traces, gravity and magnetic lineaments, and Precambrian basement fault systems. An orientation analysis of these surface and subsurface linear features was performed to detect the basic structural grains of the region. The correlation between surface linear features and subsurface oil and gas traps was assessed, and the implication of using surface lineament and fracture analysis for delineating hydrocarbon reservoirs in the Mid-Continent region discussed. It was observed that the surface linear features were extremely consistent in orientation with the gravity and magnetic lineaments and the basement faults in the Mid-Continent region. They all consist of two major sets bending northeast and northwest, representing, therefore, the basic structural grains of the region. This consistency in orientation between the surface and subsurface linear features suggests that the systematic fault systems at the basement in the Mid-Continent region have probably been reactivated many times and have propagated upward all the way to the surface. They …
Date: April 8, 1999
Creator: Guo, Genliang & and George, S.A.
Object Type: Report
System: The UNT Digital Library
Angularly resolved measurements of ion energy of vacuum arc plasmas (open access)

Angularly resolved measurements of ion energy of vacuum arc plasmas

None
Date: April 8, 2005
Creator: Anders, Andre & Yushkov, George Yu.
Object Type: Article
System: The UNT Digital Library
Anode Sheath Switching in a Carbon Nanotube Arc Plasma (open access)

Anode Sheath Switching in a Carbon Nanotube Arc Plasma

The anode ablation rate is investigated as a function of anode diameter for a carbon nanotube arc plasma. It is found that anomalously high ablation occurs for small anode diameters. This result is explained by the formation of a positive anode sheath. The increased ablation rate due to this positive anode sheath could imply greater production rate for carbon nanotubes.
Date: April 8, 2008
Creator: Abe Fetterman, Yevgeny Raitses, and Michael Keidar
Object Type: Report
System: The UNT Digital Library
Application of CZT detectors in nuclear materials safeguards (open access)

Application of CZT detectors in nuclear materials safeguards

High-resolution, gamma- and X-my spectrometry are used routinely in nuclear materials safeguards vetication measurements. These measurements are mostly performed with high-purity germanium (HJ?Ge) detectors, which require cooling at liquid-nitrogen temperatures, thus limiting their utility in field and unattended safeguards measurement applications. Sodium iodide (NaI) scintillation detectors do not require cooling, but their energy resolution (10% at 122 keV) is insu&ient for many verification measurements. Semiconductor detectors that operate at room temperatures, such as cadmium-zinc-telhuide (CZT) detectors, with energy resolution performance reaching 2.0% at 122 keV may be used for certain safeguards verification applications. We have developed hardware to utilize CZT detectors in X- and gamma-ray measurement, systems and software to apply such a system in measuring 215U enrichment for safeguards verification purposes. The paper reports on the CZT detector-based measurement system and measurement results obtained with it. The paper also discusses work on additional improvements to broaden the applications of the
Date: April 8, 1998
Creator: Clark, D; Lavietes, A D & Ruhter, W D
Object Type: Article
System: The UNT Digital Library
Application of RAM to Facility/Laboratory Design (open access)

Application of RAM to Facility/Laboratory Design

None
Date: April 8, 2008
Creator: Mohammadi, Kazem
Object Type: Article
System: The UNT Digital Library
Approximate option pricing (open access)

Approximate option pricing

As increasingly large volumes of sophisticated options (called derivative securities) are traded in world financial markets, determining a fair price for these options has become an important and difficult computational problem. Many valuation codes use the binomial pricing model, in which the stock price is driven by a random walk. In this model, the value of an n-period option on a stock is the expected time-discounted value of the future cash flow on an n-period stock price path. Path-dependent options are particularly difficult to value since the future cash flow depends on the entire stock price path rather than on just the final stock price. Currently such options are approximately priced by Monte carlo methods with error bounds that hold only with high probability and which are reduced by increasing the number of simulation runs. In this paper the authors show that pricing an arbitrary path-dependent option is {number_sign}-P hard. They show that certain types f path-dependent options can be valued exactly in polynomial time. Asian options are path-dependent options that are particularly hard to price, and for these they design deterministic polynomial-time approximate algorithms. They show that the value of a perpetual American put option (which can be computed …
Date: April 8, 1996
Creator: Chalasani, P.; Saias, I. & Jha, S.
Object Type: Report
System: The UNT Digital Library
Aquaculture Report:1976 (open access)

Aquaculture Report:1976

Growth of channel catfish (Ictalurus punctatus) and Tilapia zillii in the Reft River Geothermal Area (RRGT) geothermal waters can equal or surpass that in a commercial aquaculture facility. Fish and prawn mortality over the course of the intermediate term preliminary study did not appear to be related to any inherent geothermal water chemistry conditions. Temperature control was a problem but does not appear to be beyond design control. The absence of temperature-related mortality in channel catfish, Tilapia zilli, and yellow perch (Perca flavescens) indicates increased survival and suggests reduced expenditures for disease control. It may also allow higher fish densities in commercial aquaculture operations using geothermal water. Results of this study indicate potential for commercial aquaculture development at the Raft River Geothermal Testing Site.
Date: April 8, 1977
Creator: Campbell, Donald K.; Watson, Lynn; Kent, James C. & Johnson, Donald W.
Object Type: Report
System: The UNT Digital Library
Aspects of Holography for Theories with Hyperscaling Violation (open access)

Aspects of Holography for Theories with Hyperscaling Violation

None
Date: April 8, 2013
Creator: Dong, Xi; Harrison, Sarah; Kachru, Shamit; Torroba, Gonzalo; Wang, Huajia & /Stanford U., ITP /Stanford U., Phys. Dept. /SLAC
Object Type: Article
System: The UNT Digital Library
[Assessment of effects of surfactants in a heavy oil reservoir] (open access)

[Assessment of effects of surfactants in a heavy oil reservoir]

During the past three months we have carefully negotiated a joint venture to implement a pilot for testing the two enhanced oil recovery processes developed at CLD Technology, Inc. The technical staff at CLD Technology, Inc. has decided to model the heavy oil reserve on the Cantleberry Lease, the Jasmin oil field in Kern County, California. Staff members have designed a new sand pack to represent one-eighth (1/8) of a one, ten-acre, five-spot well pattern that will represent the sands of the Cantleberry lease. All calculated parameters are listed in Table 1. The 3-dimensional scaled physical model design represents a typical Cantleberry steamflood pattern. The design of the model will allow the creation of zones identical to those in the Cantleberry lease which will represent the shale break between the Cantleberry A'' and B'' sands. The last 3-dimensional scaled physical model experiment, needed to design the pilot, is ready to go awaiting continuous funding from the DOE.
Date: April 8, 1991
Creator: Kostura, J.A.
Object Type: Report
System: The UNT Digital Library
[Assessment of effects of surfactants in a heavy oil reservoir]. Third quarterly report, March 30, 1991 (open access)

[Assessment of effects of surfactants in a heavy oil reservoir]. Third quarterly report, March 30, 1991

During the past three months we have carefully negotiated a joint venture to implement a pilot for testing the two enhanced oil recovery processes developed at CLD Technology, Inc. The technical staff at CLD Technology, Inc. has decided to model the heavy oil reserve on the Cantleberry Lease, the Jasmin oil field in Kern County, California. Staff members have designed a new sand pack to represent one-eighth (1/8) of a one, ten-acre, five-spot well pattern that will represent the sands of the Cantleberry lease. All calculated parameters are listed in Table 1. The 3-dimensional scaled physical model design represents a typical Cantleberry steamflood pattern. The design of the model will allow the creation of zones identical to those in the Cantleberry lease which will represent the shale break between the Cantleberry ``A`` and ``B`` sands. The last 3-dimensional scaled physical model experiment, needed to design the pilot, is ready to go awaiting continuous funding from the DOE.
Date: April 8, 1991
Creator: Kostura, J. A.
Object Type: Report
System: The UNT Digital Library
Atmospheric Radiation Measurement Program Climate Research Facility Operations Quarterly Report January 1–March 31, 2010 (open access)

Atmospheric Radiation Measurement Program Climate Research Facility Operations Quarterly Report January 1–March 31, 2010

The U.S. Department of Energy (DOE) requires national user facilities to report time-based operating data. The requirements concern the actual hours of operation (ACTUAL); the estimated maximum operation or uptime goal (OPSMAX), which accounts for planned downtime; and the VARIANCE [1 – (ACTUAL/OPSMAX)], which accounts for unplanned downtime.
Date: April 8, 2010
Creator: Sisterson, D. L.
Object Type: Report
System: The UNT Digital Library
Authorized Limits for the Release of a 25 Ton Locomotive, Serial Number 21547, at the Area 25 Engine Maintenance, Assembly, and Disassembly Facility, Nevada Test Site, Nevada (open access)

Authorized Limits for the Release of a 25 Ton Locomotive, Serial Number 21547, at the Area 25 Engine Maintenance, Assembly, and Disassembly Facility, Nevada Test Site, Nevada

This document contains process knowledge and radiological data and analysis to support approval for release of the 25-ton locomotive, Serial Number 21547, at the Area 25 Engine Maintenance, Assembly, and Disassembly (EMAD) Facility, located on the Nevada Test Site (NTS). The 25-ton locomotive is a small, one-of-a-kind locomotive used to move railcars in support of the Nuclear Engine for Rocket Vehicle Application project. This locomotive was identified as having significant historical value by the Nevada State Railroad Museum in Boulder City, Nevada, where it will be used as a display piece. A substantial effort to characterize the radiological conditions of the locomotive was undertaken by the NTS Management and Operations Contractor, National Security Technologies, LLC (NSTec). During this characterization process, seven small areas on the locomotive had contamination levels that exceeded the NTS release criteria (limits consistent with U.S. Department of Energy [DOE] Order DOE O 5400.5, “Radiation Protection of the Public and the Environment”). The decision was made to perform radiological decontamination of these known accessible impacted areas to further the release process. On February 9, 2010, NSTec personnel completed decontamination of these seven areas to within the NTS release criteria. Although all accessible areas of the locomotive had …
Date: April 8, 2010
Creator: Frenette, Jeremy Gwin and Douglas
Object Type: Report
System: The UNT Digital Library
Automated solar panel assembly line. LSA task: production processes and equipment. Quarterly report No. 1 (open access)

Automated solar panel assembly line. LSA task: production processes and equipment. Quarterly report No. 1

The objective of this program is to design, fabricate and demonstrate an automated solar cell module production line with the ultimate goal of reducing module assembly costs. During this reporting period the automated module design was completed. The design of the solar cell assembly prototype (SCAP) was about 75% completed and the solar panel lamination prototype (SPLP) was built and tested.
Date: April 8, 1979
Creator: Somberg, H.
Object Type: Report
System: The UNT Digital Library
Basin Analysis of the Mississippi Interior Salt Basin and Petroleum System Modeling of the Jurassic Smackover Formation, Eastern Gulf Coastal Plain (open access)

Basin Analysis of the Mississippi Interior Salt Basin and Petroleum System Modeling of the Jurassic Smackover Formation, Eastern Gulf Coastal Plain

The objective is to provide a comprehensive geologic analysis of the Mississippi Interior Salt Basin.
Date: April 8, 1998
Creator: Mancini, Ernest A.
Object Type: Report
System: The UNT Digital Library
Beam Transfer Lines for the Spallation Neutron Source. (open access)

Beam Transfer Lines for the Spallation Neutron Source.

Beam transfer lines for the Spallation Neutron Source (SNS) are designed to have low beam losses for hand on maintenance while satisfying the facility footprint requirements. There are two main beam transfer lines, High Energy Beam Transport (HEBT) line which connect super conducting linac to the accumulator ring and Ring to Target Beam transport (RTBT) which transfers beam from accumulator ring to the target. HEBT line not only transfer the beam from linac to ring but also prepare beam for ring injection, correct the energy jitter from the linac, provide required energy spread for the ring injection, clean the transverse and longitudinal halo particles from the beam, determine the linac beam quality, and provide the protection to the accumulator ring. RTBT line transport the beam from ring to target while fulfilling the target requirements of beam size, maximum current density, beam moment on the target in case of ring extraction kicker failure. and protect the target from the ring fault conditions.
Date: April 8, 2002
Creator: Raparia, D.; Lee, Y. Y.; Weng, W. T. & Wei, J.
Object Type: Article
System: The UNT Digital Library
Biotic and Abiotic Transformation of a Volatile Organics Plume in a Semi-Arid Vadose Zone (open access)

Biotic and Abiotic Transformation of a Volatile Organics Plume in a Semi-Arid Vadose Zone

An evaluation of biotic and abiotic attenuation processes potentially important to chlorinated and non-chlorinated volatile organic compound (VOC) fate and transport in the 148 meter thick vadose zone beneath the Chemical Waste Landfill (CWL) was conducted. A unique feature of this evaluation is the comparison of two estimates of VOC mass present in the soil gas, pore-water, and solid phases (but not including mass as non-aqueous phase liquid [NAPL]) of the vadose zone in 1993. One estimate, 1,800 kg, was obtained from vadose zone transport modeling that incorporated molecular diffusion and volatilization to the atmosphere, but not biotic or chemical processes. The other estimate, 2,120 kg, was obtained from the sum of VOC mass physically removed during soil vapor extraction and an estimate of VOC mass remaining in the vadose zone in 1998, both adjusted to exclude NAPL mass. This comparison indicates that biogeochemical processes were at best slightly important to historical VOC plume development. Some evidence of aerobic degradation of non-chlorinated VOCs and abiotic transformation of 1,1,1-Trichloroethane was identified. Despite potentially amenable site conditions, no evidence was found of cometabolic and anaerobic transformation pathways. Relying principally on soil-gas analytical results, an upper-bound estimate of 21% mass reduction due to …
Date: April 8, 1999
Creator: Studer, J. E.; Singletary, M.A. & Miller, D. R.
Object Type: Article
System: The UNT Digital Library