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Determination of Abraham model solute descriptors for the monomeric and dimeric forms of trans-cinnamic acid using measured solubilities from the Open Notebook Science Challenge

Description: Article on the determination of Abraham model solute descriptors for the monomeric and dimeric forms of trans-cinnamic acid using measured solubilities from the Open Notebook Science Challenge.
Date: September 25, 2014
Creator: Bradley, Jean-Claude; Abraham, M. H. (Michael H.); Acree, William E. (William Eugene); Lang, Andrew S. I. D.; Beck, Samantha N.; Bulger, David A. et al.
Partner: UNT College of Arts and Sciences

Predicting Abraham model solvent coefficients

Description: Article on predicting Abraham model solvent coefficients.
Date: October 10, 2014
Creator: Bradley, Jean-Claude; Abraham, M. H. (Michael H.); Acree, William E. (William Eugene) & Lang, Andrew S. I. D.
Partner: UNT College of Arts and Sciences

A note on simulation and dynamical hierarchies

Description: This paper summarizes some of the problems associated with the generation of higher order emergent structures in formal dynamical systems as well as some of the formal properties of dynamical systems capable of generating higher order structures.
Date: February 22, 1996
Creator: Rasmussen, S.; Barrett, C. L.; Baas, N. A. & Olesen, M. W.
Partner: UNT Libraries Government Documents Department

Meson spectrum from the Bethe-Salpeter equation

Description: We present details of a model for calculating the mass spectrum of light-quark mesons and decay constants of the pseudoscalar meson octet from a phenomenological model based on Dyson-Schwinger and Bethe-Salpeter equations. In this model the Bethe-Salpeter kernel is approximated by a separable ansatz obtained from input quark propagators. 13 refs., 2 tabs.
Date: January 22, 1996
Creator: Burden, C. J.; Qian, L.; Tandy, P. C.; Roberts, C. D. & Thomson, M. J.
Partner: UNT Libraries Government Documents Department

Lessons Learned from Characterization, Performance Assessment, and EPA Regulatory Review of the 1996 Actinide Source Term for the Waste Isolation Pilot Plant

Description: The Waste Isolation Pilot Plant (WIPP) is a US Department of Energy (DOE) facility for the permanent disposal of transuranic waste from defense activities. In 1996, the DOE submitted the Title 40 CFR Part 191 Compliance Certification Application for the Waste Isolation Pilot Plant (CCA) to the US Environmental Protection Agency (EPA). The CCA included a probabilistic performance assessment (PA) conducted by Sandia National Laboratories to establish compliance with the quantitative release limits defined in 40 CFR 191.13. An experimental program to collect data relevant to the actinide source term began around 1989, which eventually supported the 1996 CCA PA actinide source term model. The actinide source term provided an estimate of mobile dissolved and colloidal Pu, Am, U, Th, and Np concentrations in their stable oxidation states, and accounted for effects of uncertainty in the chemistry of brines in waste disposal areas. The experimental program and the actinide source term included in the CCA PA underwent EPA review lasting more than 1 year. Experiments were initially conducted to develop data relevant to the wide range of potential future conditions in waste disposal areas. Interim, preliminary performance assessments and actinide source term models provided insight allowing refinement of experiments and models. Expert peer review provided additional feedback and confidence in the evolving experimental program. By 1995, the chemical database and PA predictions of WIPP performance were considered reliable enough to support the decision to add an MgO backfill to waste rooms to control chemical conditions and reduce uncertainty in actinide concentrations, especially for Pu and Am. Important lessons learned through the characterization, PA modeling, and regulatory review of the actinide source term are (1) experimental characterization and PA should evolve together, with neither activity completely dominating the other, (2) the understanding of physical processes required to develop conceptual models is ...
Date: March 22, 1999
Creator: Larson, K.W.; Moore, R.C.; Nowak, E.J.; Papenguth, H.W. & Jow, H.
Partner: UNT Libraries Government Documents Department

Environmental Measurement-While-Drilling System for Real-Time Field Screening of Contaminants

Description: Sampling during environmental drilling is essential to fully characterize the spatial distribution and migration of near surface contaminants. However, analysis of the samples is expensive and time-consuming: off-site laboratory analysis can take weeks or months. An alternative screening technology, Environmental Measurement-While-Drilling (EMWD), could save money and valuable time by quickly distinguishing between contaminated and uncontaminated areas. Real time measurements provided by an EMWD system enable on-the-spot decisions to be made regarding sampling strategies. The system also enhances worker safety and provides the added flexibility of being able to steer a drill bit in or out of hazardous zones.
Date: February 22, 1999
Creator: Bishop, L.B.; Lockwood, G.J.; Normann, R.A.; Selph, M.M. & Williams, C.V.
Partner: UNT Libraries Government Documents Department

Managing Performance Analysis with Dynamic Statistical Projection Pursuit

Description: Computer systems and applications are growing more complex. Consequently, performance analysis has become more difficult due to the complex, transient interrelationships among runtime components. To diagnose these types of performance issues, developers must use detailed instrumentation to capture a large number of performance metrics. Unfortunately, this instrumentation may actually influence the performance analysis, leading the developer to an ambiguous conclusion. In this paper, we introduce a technique for focusing a performance analysis on interesting performance metrics. This technique, called dynamic statistical projection pursuit, identifies interesting performance metrics that the monitoring system should capture across some number of processors. By reducing the number of performance metrics, projection pursuit can limit the impact of instrumentation on the performance of the target system and can reduce the volume of performance data.
Date: May 22, 2000
Creator: Vetter, J.S. & Reed, D.A.
Partner: UNT Libraries Government Documents Department

METALLIZATION OF CERAMIC VACUUM CHAMBERS FOR SNS RING INJECTION KICKER MAGNETS.

Description: Ceramic chambers will be used in the pulsed kicker magnets for the injection of H{sup -} into the US Spallation Neutron Source (SNS) accumulator ring. There are two reasons for using ceramic chambers in kickers: (1) to avoid shielding of a fast-changing external magnetic field by metallic chamber walls; and (2) to reduce heating due to eddy currents. The inner surfaces of the ceramic chambers will be coated with a conductive layer, possibly titanium (Ti) or copper with a titanium nitride (TiN) overlayer, to reduce the beam coupling impedance and provide passage for beam image current. This paper describes the development of sputtering method for the 0.83m long 16cm inner diameter ceramic chambers. Coatings of Ti, Cu and TiN with thicknesses up to 10 {micro}m were produced by means of DC magnetron sputtering. The difficulty of coating insulators was overcome with the introduction of an anode screen. Films with good adhesion, uniform longitudinal thickness, and conductivity were produced.
Date: April 22, 2002
Creator: He, P.; Hseuh, H. C. & Todd, R. J.
Partner: UNT Libraries Government Documents Department

Utilizing Strong Tight Intermodal Waste Packaging to Meet Accelerated Cleanup Goals at The Savannah River Site

Description: In support of the accelerated cleanup challenge, personnel at the Savannah River Site have been working diligently to identify and acquire cost-effective waste containers that can be used to package a voluminous amount of low level radioactive waste that needs to be disposed. In so doing, personnel have transformed their paradigm in packaging low level radioactive waste in traditional 45-cubic-foot and 90-cubic-foot containers and utilizing refurbished intermodal containers instead. The transition has increased efficiencies in the processing, packaging, transportation, storage, and disposal of low level radioactive waste, while providing decreased procurement costs. Since large items do not have to be size-reduced to fit into the large containers, additional cost savings are being realized by minimizing void space, labor, time, equipment, and risks if size reduction techniques were performed. Cost savings for fiscal year 2003 exceeded one million dollars. Additional savings are estimated to be between 3 million dollars and 4 million dollars through fiscal year 2006.
Date: January 22, 2004
Creator: Kinney, JosephC.
Partner: UNT Libraries Government Documents Department

Observations on the luminosity lifetimes, emittance growth rates and intra-beam scattering at the Tevatron

Description: A record luminosity of 4.2 10{sup 31}has been reached at the Fermilab p-{bar p} collider. The lifetime of this luminosity at the beginning of the store is about 10 hours. This lifetime can be explained by the measured loss of anti-protons and protons due to collisions and emittance growths. We report on transverse emittance growth rates based on our Synchrotron Light Monitor. Longitudinal emittance growth rate measurements are based on the TeV Sampled Bunch Display data. It is shown that Intra Beam Scattering is a significant source of emittance growth rates. We comment on other possible factors for these observed emittance growth rates. Finally, we comment on future luminosity lifetimes, as we hope to further increase our peak luminosity.
Date: May 22, 2003
Creator: al., Paul L.G. Lebrun et
Partner: UNT Libraries Government Documents Department

Optics of a Proton Driver

Description: In a four month study, a design for a Proton Driver was developed as a possible replacement for Fermilab's Booster. Its optical properties are summarized briefly.
Date: May 22, 2003
Creator: al., Leo Michelotti et
Partner: UNT Libraries Government Documents Department

Energy levels of isoelectronic impurities by large scale LDA calculations

Description: Isoelectronic impurity states are localized states induced by stoichiometric single atom substitution in bulk semiconductor. Photoluminescence spectra indicate deep impurity levels of 0.5 to 0.9eV above the top of valence band for systems like: GaN:As, GaN:P, CdS:Te, ZnS:Te. Previous calculations based on small supercells seemingly confirmed these experimental results. However, the current ab initio calculations based on thousand atom supercells indicate that the impurity levels of the above systems are actually much shallower(0.04 to 0.23 eV), and these impurity levels should be compared with photoluminescence excitation spectra, not photoluminescence spectra.
Date: November 22, 2002
Creator: Li, Jingbo & Wang, Lin-Wang
Partner: UNT Libraries Government Documents Department

Jet production at CDF

Description: In this talk I present the results from the measurement of the inclusive jet cross section and strong coupling constant based on the CDF Run 1B data, and discuss prospects for Run 2.
Date: April 22, 2002
Creator: Mesropian, Christina
Partner: UNT Libraries Government Documents Department

Progress in heavy-ion drivers for inertial fusion

Description: Heavy-ion induction accelerators are being developed as fusion drivers for ICF power production in the US Inertial Fusion Energy (IFE) program, in the Office of Fusion Energy of the US Department of Energy. In addition, they represent an attractive driver option for a high-yield microfusion facility for defense research. This paper describes recent progress in induction drivers for Heavy-Ion Fusion (HIF), and plans for future work. It presents research aimed at developing drivers having reduced cost and size, specifically advanced induction linacs and recirculating induction accelerators (recirculators). The goals and design of the Elise accelerator being built at Lawrence Berkeley Laboratory (LBL), as the first stage of the ILSE (Induction Linac Systems Experiments) program, are described. Elise will accelerate, for the first time, space-charge-dominated ion beams which are of full driver scale in line-charge density and diameter. Elise will be a platform on which the critical beam manipulations of the induction approach can be explored. An experimental program at Lawrence Livermore National Laboratory (LLNL) exploring the recirculator principle on a small scale is described in some detail; it is expected that these studies will result ultimately in an operational prototype recirculating induction accelerator. In addition, other elements of the US HIF program are described.
Date: December 22, 1994
Creator: Friedman, A.; Bangerter, R.O. & Herrmannsfeldt, W.B.
Partner: UNT Libraries Government Documents Department

Research perspectives on the evaluation of steam generator tube integrity.

Description: Industry effects have been largely successful in managing degradation of steam generator tubes due to wastage, pitting, and denting, but fretting, SCC and intergranular attack have proved more difficult to manage. Although steam generator replacements are proceeding there is substantial industry interest in operating with degraded steam generators, and significant numbers of plants will continue to do so. In most cases degradation of steam generator tubing by stress corrosion cracking is still managed by plug or repair on detection, because current NDE techniques for characterization of flaws are not accurate enough to permit continued operation. This paper reviews some of the historical background that underlies current steam generator degradation management strategies and outlines some of the additional research that must be done to provide more effective management of degradation in current generators and provide greater assurance of satisfactory performance in replacement steam generators.
Date: February 22, 2001
Creator: Muscara, J.; Diercks, D. R.; Majumdar, S.; Kupperman, D. S.; Bakhtiari, S. & Shack, W. J.
Partner: UNT Libraries Government Documents Department

Uranium Co-Precipitation with Iron Oxide Minerals

Description: In oxidizing environments, the toxic and radioactive element uranium is most soluble and mobile in the hexavalent oxidation state. These processes also affect the biological availability of U(VI) species toward reduction and precipitation as the less soluble U(IV) species by metal-reducing bacteria. The results provide compelling evidence of U incorporation within the hematite structure.
Date: May 22, 2002
Creator: Duff, M.C.
Partner: UNT Libraries Government Documents Department

Non-neutral plasma science issues for heavy ion drivers

Description: The main non-neutral plasma science issue in heavy ion drivers is focusability at the target. Considerations of the intrinsic six-dimensional phase volume at the beginning of the accelerator, and the required six dimensional phase volume required at the target, suggests there exists accelerator designs in which there is a reasonably large leeway to allow adequate focusability. Space-charge effects may also be controlled by properly designed neutralization methods, or large beam numbers, or high beam kinetic energy (and hence reduced currents for fixed target yield). Known beam instabilities also must be considered in the accelerator design. Errors in the focusing and accelerating systems also contribute to emittance growth. Simulations must play a crucial role in determining the level of errors that allow the accelerator to meet the focusing requirements, and in ensuring that beam instabilities are benign.
Date: January 22, 1999
Creator: Barnard, J J
Partner: UNT Libraries Government Documents Department

Numerical simulation studies of gas production scenarios from hydrate accumulations at the Mallik Site, McKenzie Delta, Canada

Description: The Mallik site represents an onshore permafrost-associated gas hydrate accumulation in the Mackenzie Delta, Northwest Territories, Canada. An 1150 m deep gas hydrate research well was drilled at the site in 1998. The objective of this study is the analysis of various gas production scenarios from several gas-hydrate-bearing zones at the Mallik site. The TOUGH2 general-purpose simulator with the EOSHYDR2 module were used for the analysis. EOSHYDR2 is designed to model the non-isothermal CH{sub 4} (methane) release, phase behavior and flow under conditions typical of methane-hydrate deposits by solving the coupled equations of mass and heat balance, and can describe any combination of gas hydrate dissociation mechanisms. Numerical simulations indicated that significant gas hydrate production at the Mallik site was possible by drawing down the pressure on a thin free-gas zone at the base of the hydrate stability field. Gas hydrate zones with underlying aquifers yielded significant gas production entirely from dissociated gas hydrate, but large amounts of produced water. Lithologically isolated gas-hydrate-bearing reservoirs with no underlying free gas or water zones, and gas-hydrate saturations of at least 50% were also studied. In these cases, it was assumed that thermal stimulation by circulating hot water in the well was the method used to induce dissociation. Sensitivity studies indicated that the methane release from the hydrate accumulations increases with gas-hydrate saturation, the initial formation temperature, the temperature of the circulating water in the well, and the formation thermal conductivity. Methane production appears to be less sensitive to the rock and hydrate specific heat and permeability of the formation.
Date: March 22, 2002
Creator: Moridis, George J.; Collett, Timothy S.; Dallimore, Scott R.; Satoh, Tohru; Hancock, Stephen & Weatherill, Brian
Partner: UNT Libraries Government Documents Department