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Shielding of a hadron in a finite e-beam (open access)

Shielding of a hadron in a finite e-beam

The thorough study of coherent electron cooling, the modern cooling technique capable to deal with accelerators operating in the range of few TeVs, rises many interesting questions. One of them is a shielding dynamics of a hadron in an electron beam. Now this effect is computed analytically in the infinite beam approximation. Many effects are drastically different in finite and infinite plasmas. Here we propose a method to compute the dynamical shielding effect in a finite cylindrical plasma - the realistic model of an electron beam in accelerators.
Date: May 20, 2012
Creator: A., Elizarov; Litvinenko, V. & Wang, G.
System: The UNT Digital Library
Diagnostics for the Biased Electrode Experiment on NSTX (open access)

Diagnostics for the Biased Electrode Experiment on NSTX

A linear array of four small biased electrodes was installed in NSTX in an attempt to control the width of the scrape-off layer (SOL) by creating a strong local poloidal electric field. The set of electrodes were separated poloidally by a 1 cm gap between electrodes and were located slightly below the midplane of NSTX, 1 cm behind the RF antenna and oriented so that each electrode is facing approximately normal to the magnetic field. Each electrode can be independently biased to ±100 volts. Present power supplies limit the current on two electrodes to 30 amps the other two to 10 amps each. The effect of local biasing was measured with a set of Langmuir probes placed between the electrodes and another set extending radially outward from the electrodes, and also by the gas puff imaging diagnostic (GPI) located 1 m away along the magnetic field lines intersecting the electrodes. Two fast cameras were also aimed directly at the electrode array. The hardware and controls of the biasing experiment will be presented and the initial effects on local plasma parameters will be discussed.
Date: March 20, 2009
Creator: A.L. Roquemore, S.J. Zweben, C.E. Bush, R. Kaita, R. J. Marsalsa, and R.J. Maqueda
System: The UNT Digital Library
Chemometric Analysis of Nuclear Magnetic Resonance Spectroscopy Data (open access)

Chemometric Analysis of Nuclear Magnetic Resonance Spectroscopy Data

Chemometric analysis of nuclear magnetic resonance (NMR) spectroscopy has increased dramatically in recent years. A variety of different chemometric techniques have been applied to a wide range of problems in food, agricultural, medical, process and industrial systems. This article gives a brief review of chemometric analysis of NMR spectral data, including a summary of the types of mixtures and experiments analyzed with chemometric techniques. Common experimental problems encountered during the chemometric analysis of NMR data are also discussed.
Date: July 20, 2000
Creator: ALAM,TODD M. & ALAM,M. KATHLEEN
System: The UNT Digital Library
Evaluation of cracking in the 241-AZ tank farm ventilation line at the Hanford Site (open access)

Evaluation of cracking in the 241-AZ tank farm ventilation line at the Hanford Site

In the period from April to October of 1988, a series of welding operations on the outside of the AZ Tank Farm ventilation line piping at the Hanford Site produced unexpected and repeated cracking of the austenitic stainless steel base metal and of a seam weld in the pipe. The ventilation line is fabricated from type 304L stainless steel pipe of 24 inch diameter and 0.25 inch wall thickness. The pipe was wrapped in polyethylene bubble wrap and buried approximately 12 feet below grade. Except for the time period between 1980 and 1987, impressed current cathodic protection has been applied to the pipe since its installation in 1974. The paper describes the history of the cracking of the pipe, the probable cracking mechanisms, and the recommended future action for repair/replacement of the pipe.
Date: October 20, 1999
Creator: ANANTATMULA, R.P.
System: The UNT Digital Library
Land-Based Geologic Emplacement of Mercury Wastes (open access)

Land-Based Geologic Emplacement of Mercury Wastes

None
Date: July 20, 2000
Creator: ANDERSON,D. RICHARD
System: The UNT Digital Library
Bipolaron Hopping Conduction in Boron Carbides (open access)

Bipolaron Hopping Conduction in Boron Carbides

The electrical conductivities of boron carbides, B{sub 12+x}C{sub 3{minus}x} with 0.1 < x < 1.7, between 300 and 1200K suggest the hopping of a nearly temperature-independent density of small (bi)polarons. The activation energies of the nobilities are low, {approx} 0.16 eV, and are nearly independent of the composition. At lower temperatures, conductivities have non-Arrhenius temperature dependencies and strong sensitivity to carbon concentration. Percolative aspects of low-temperature hopping are evident in this sensitivity to composition. Boron carbides' Seebeck coefficients are anomalous in that (1) they are much larger than expected from boron carbides' large carrier densities and (2) they depend only weakly on the carrier density. Carrier-induced softening of local vibrations gives contributions to the Seebeck coefficient that mirror the magnitudes and temperature dependencies found in boron carbides.
Date: September 20, 1999
Creator: ASELAGE, TERRENCE L.; EMIN, D. & MCCREADY, STEVEN S.
System: The UNT Digital Library
Conductivities and Seebeck Coefficients of Boron Carbides: ''Softening-Bipolaron'' Hopping (open access)

Conductivities and Seebeck Coefficients of Boron Carbides: ''Softening-Bipolaron'' Hopping

The most conspicuous feature of boron carbides' electronic transport properties is their having both high carrier densities and large Seebeck coefficients. The magnitudes and temperature dependencies of the Seebeck coefficients are consistent with large contributions from softening bipolarons: singlet bipolarons whose stabilization is significantly affected by their softening of local vibrations. Boron carbides' high carrier densities, small activation energies for hopping ({approx} 0.16 eV), and anomalously large Seebeck coefficients combine with their low, glass-like thermal conductivities to make them unexpectedly efficient high-temperature thermoelectrics.
Date: July 20, 2000
Creator: ASELAGE,TERRENCE L.; EMIN,DAVID JACOB & MCCREADY,STEVEN S.
System: The UNT Digital Library
Search for Strong Gravity Signatures in Same-Sign Dimuon Final States Using the ATLAS Detector at the LHC (open access)

Search for Strong Gravity Signatures in Same-Sign Dimuon Final States Using the ATLAS Detector at the LHC

None
Date: May 20, 2013
Creator: Aad, Georges
System: The UNT Digital Library
Search for High-Mass States with One Lepton Plus Missing Transverse Momentum in Proton-Proton Collisions at $\sqrt{s} with the ATLAS Detector (open access)

Search for High-Mass States with One Lepton Plus Missing Transverse Momentum in Proton-Proton Collisions at $\sqrt{s} with the ATLAS Detector

The ATLAS detector is used to search for high-mass states, such as heavy charged gauge bosons (W{prime},W*), decaying to a charged lepton (electron or muon) and a neutrino. Results are presented based on the analysis of ppcollisions at a center-of-mass energy of 7 TeV corresponding to an integrated luminosity of 36 pb{sup -1}. No excess beyond standard model expectations is observed. A W{prime} with sequential standard model couplings is excluded at 95% confidence level for masses below 1.49 TeV, and a W* (charged chiral boson) for masses below 1.35 TeV.
Date: June 20, 2012
Creator: Aad, Georges; Abbott, Brad; Abdallah, Jalal; Abdelalim, Ahmed Ali; Abdesselam, Abdelouahab; Abdinov, Ovsat et al.
System: The UNT Digital Library
Combination of CDF and D0 Measurements of the $W$ Boson Helicity in Top Quark Decays (open access)

Combination of CDF and D0 Measurements of the $W$ Boson Helicity in Top Quark Decays

This report talks about Combination of CDF and D0 Measurements of the $W$ Boson Helicity in Top Quark Decays
Date: April 20, 2012
Creator: Aaltonen, T
System: The UNT Digital Library
Plasma-Enhanced SCR of NOx in Simulated Heavy-Duty Exhaust: Sulfur, Hydrocarbon, and Temperature Effects (open access)

Plasma-Enhanced SCR of NOx in Simulated Heavy-Duty Exhaust: Sulfur, Hydrocarbon, and Temperature Effects

None
Date: August 20, 2000
Creator: Aardahl, C. L.
System: The UNT Digital Library
An Extensible Business Process Approach for Managing Institutional Roles & Responsibilities ? A New Horizon for LLNL (open access)

An Extensible Business Process Approach for Managing Institutional Roles & Responsibilities ? A New Horizon for LLNL

None
Date: September 20, 2006
Creator: Aaron, C
System: The UNT Digital Library
Developing a Panelboard Trainer Using SIMVOX and PROVOX (open access)

Developing a Panelboard Trainer Using SIMVOX and PROVOX

Several challenges existed in creating a system that would be valuable for training operators: the robustness and accuracy of the process model, the operator interface to the process, and the communication between the operator interface and the process models. Cost and implementation time were also important factors. Two possible implementation plans were examined. The first option was to develop a computer tool through which the operator could operate the process through interaction with the mouse and keyboard. The entire panel board system could be created in computer graphics and a process model attached. The second option was to construct a complete replica of the control room panelboard in a training environment. Operations personnel expressed a strong preference for creating the panel board replica. Concerns were expressed about the comfort level of the operators training on a computer tool, and the value of the operators becoming thoroughly familiar with the physical location of the equipment in the panelboard was believed to be high. It was therefore decided to create a replica of the control room panelboard.
Date: November 20, 1995
Creator: Abbott, L. A.
System: The UNT Digital Library
Provably Secure Password-based Authentication in TLS (open access)

Provably Secure Password-based Authentication in TLS

In this paper, we show how to design an efficient, provably secure password-based authenticated key exchange mechanism specifically for the TLS (Transport Layer Security) protocol. The goal is to provide a technique that allows users to employ (short) passwords to securely identify themselves to servers. As our main contribution, we describe a new password-based technique for user authentication in TLS, called Simple Open Key Exchange (SOKE). Loosely speaking, the SOKE ciphersuites are unauthenticated Diffie-Hellman ciphersuites in which the client's Diffie-Hellman ephemeral public value is encrypted using a simple mask generation function. The mask is simply a constant value raised to the power of (a hash of) the password.The SOKE ciphersuites, in advantage over previous pass-word-based authentication ciphersuites for TLS, combine the following features. First, SOKE has formal security arguments; the proof of security based on the computational Diffie-Hellman assumption is in the random oracle model, and holds for concurrent executions and for arbitrarily large password dictionaries. Second, SOKE is computationally efficient; in particular, it only needs operations in a sufficiently large prime-order subgroup for its Diffie-Hellman computations (no safe primes). Third, SOKE provides good protocol flexibility because the user identity and password are only required once a SOKE ciphersuite has …
Date: December 20, 2005
Creator: Abdalla, Michel; Emmanuel, Bresson; Chevassut, Olivier; Moeller,Bodo & Pointcheval, David
System: The UNT Digital Library
Birth Order and Divergent Thinking: A Meta-Analysis (open access)

Birth Order and Divergent Thinking: A Meta-Analysis

This article is a meta-analysis examining the association of birth order and divergent thinking (DT). The main purpose was to examine how ordinal position (only, first, middle, or last-born) is related to creativity. Results showed that first-borns had higher DT scores than later-born children.
Date: April 20, 2021
Creator: Abdulla Alabbasi, Ahmed M.; Tadik, Harun; Acar, Selcuk & Runco, Mark A.
System: The UNT Digital Library
Using the Antenna Effect as a Spectroscopic Tool; Photophysics and Solution Thermodynamics of the Model Luminescent Hydroxypyridonate Complex [EuIII(3,4,3-LI(1,2-HOPO))]- (open access)

Using the Antenna Effect as a Spectroscopic Tool; Photophysics and Solution Thermodynamics of the Model Luminescent Hydroxypyridonate Complex [EuIII(3,4,3-LI(1,2-HOPO))]-

While widely used in bioassays, the spectrofluorimetric method described here uses the antenna effect as a tool to probe the thermodynamic parameters of ligands that sensitize lanthanide luminescence. The Eu3+ coordination chemistry, solution thermodynamic stability and photophysical properties of the spermine-based hydroxypyridonate octadentate chelator 3,4,3-LI(1,2-HOPO) are reported. The complex [EuIII(3,4,3-LI(1,2-HOPO))]- luminesces with a long lifetime (805 mu s) and a quantum yield of 7.0percent in aqueous solution, at pH 7.4. These remarkable optical properties were exploited to determine the high (and proton-independent) stability of the complex (log beta 110 = 20.2(2)) and to define the influence of the ligand scaffold on the stability and photophysical properties.
Date: November 20, 2009
Creator: Abergel, Rebecca J.; D'Aleo, Anthony; Ng Pak Leung, Clara; Shuh, David & Raymond, Kenneth
System: The UNT Digital Library
Model for the prediction of the pressure-volume relationship of porous rocks (open access)

Model for the prediction of the pressure-volume relationship of porous rocks

Several models have been suggested to describe the volume behavior of porous materials under hydrostatic loading. The model presented here accounts for variations in both porosity and the amount of fluid contained within that porosity. The model also attempts to predict the one-dimensional strain loading pressure-volume relationship and the stress difference-confining pressure curve. Only the simplest assumptions were used for the development of this model. These assumptions are discussed and the predictions for Mt. Helen tuff are compared to experimental data.
Date: July 20, 1976
Creator: Abey, A. E.
System: The UNT Digital Library
Influence of EGR on Component Durability (open access)

Influence of EGR on Component Durability

None
Date: August 20, 2000
Creator: Abi-Akar, Hind
System: The UNT Digital Library
Characterization of oxidation products on a ZrFe{sub 2}-type laves intermetallic exposed to 200{degree}C steam. (open access)

Characterization of oxidation products on a ZrFe{sub 2}-type laves intermetallic exposed to 200{degree}C steam.

The release of radioactive elements from the stainless steel-15 wt% zirconium (SS-15Zr) metal waste form will be governed by the corrosion behavior of ZrFe{sub 2}-type intermetallics phases present in the alloy. In this article, oxidation products that formed on a ZrFe{sub 2}-type intermetallic sample exposed to 200 C steam were characterized by Auger Electron Spectroscopy (AES) and Transmission Electron Microscopy (TEM). The data revealed two oxide layers on the sample surface: an outer crystalline iron-oxide layer and an inner amorphous zirconium-rich layer believed to be zirconium oxide. Thermodynamic considerations indicate that the zirconium-rich layer formed first. The iron-oxide layer appears to have resulted from the diffusion of iron through the zirconium-rich layer to the oxide-vapor interface.
Date: November 20, 2000
Creator: Abraham, D. P.; Dietz, N. & Finnegan, N.
System: The UNT Digital Library
Air to Muscle and Blood/Plasma to Muscle Distribution of Volatile Organic Compounds and Drugs: Linear Free Energy Analyses (open access)

Air to Muscle and Blood/Plasma to Muscle Distribution of Volatile Organic Compounds and Drugs: Linear Free Energy Analyses

Article on air to muscle and blood/plasma to muscle distribution of volatile organic compounds and drugs and linear free energy analyses.
Date: April 20, 2006
Creator: Abraham, M. H. (Michael H.); Ibrahim, Adam & Acree, William E. (William Eugene)
System: The UNT Digital Library
U.S./Russian cooperative efforts to enhance nuclear MPC&A at VNIITF, (Chelyabinsk-70) (open access)

U.S./Russian cooperative efforts to enhance nuclear MPC&A at VNIITF, (Chelyabinsk-70)

The work described here is part of an effort called the Nuclear Materials Protection, Control, and Accounting (MPC&A) Program, a cooperative program between the US Department of Eenrgy (DOE) and Russia's Ministry of Atomic Energy (MinAtom). The objective of the program is to reduce the risk of nuclear proliferation by strengthening MPC&A systems at Russian nuclear Facilities. This paper describes that portion of the MPC&A program that is directed specifically to the needs of the All Russian Scientific Research Institute of Technical Physics (VNIITF), also called Chelyabinsk-70. A major MPC&A milestone was met at VNIITF when the MPC&A improvements were commissioned at the Pulse Research Reactor Facility in May of this year.
Date: April 20, 1999
Creator: Abramson, B.; Apt, K.; Blasy, J.; Bukin, D.; Churikov, Y.; Curtis, D. et al.
System: The UNT Digital Library
Optimum flywheel sizing for parallel and series hybrid vehicles (open access)

Optimum flywheel sizing for parallel and series hybrid vehicles

Flywheels have the possibility of providing high turnaround efficiency and high specific power output. These characteristics are very important for the successful manufacture of parallel and series hybrid vehicles, which have the potential for providing high fuel economy and very low emissions with range and performance comparable to today`s light-duty vehicles. Flywheels have a high specific power output, but relatively low specific energy output. Therefore, it is of importance to determine energy and power requirements for flywheels applied to light-duty vehicles. Vehicle applications that require an energy storage system with high power and low energy are likely to benefit from a flywheel. In this paper, a vehicle simulation code and a flywheel model are applied to the calculation of optimum flywheel energy storage capacity for a parallel and a series hybrid vehicle. A conventional vehicle is also evaluated as a base-case, to provide an indication of the fuel economy gains that can be obtained with flywheel hybrid vehicles. The results of the analysis indicate that the optimum flywheel energy storage capacity is relatively small. This results in a low weight unit that has a significant power output and high efficiency. Emissions generated by the hybrid vehicles are not calculated, but …
Date: December 20, 1996
Creator: Aceves, S. M. & Smith, J. R.
System: The UNT Digital Library
Spatial Analysis of Emissions Sources for HCCI Combustion at Low Loads Using a Multi-Zone Model (open access)

Spatial Analysis of Emissions Sources for HCCI Combustion at Low Loads Using a Multi-Zone Model

We have conducted a detailed numerical analysis of HCCI engine operation at low loads to investigate the sources of HC and CO emissions and the associated combustion inefficiencies. Engine performance and emissions are evaluated as fueling is reduced from typical HCCI conditions, with an equivalence ratio f = 0.26 to very low loads (f = 0.04). Calculations are conducted using a segregated multi-zone methodology and a detailed chemical kinetic mechanism for iso-octane with 859 chemical species. The computational results agree very well with recent experimental results. Pressure traces, heat release rates, burn duration, combustion efficiency and emissions of hydrocarbon, oxygenated hydrocarbon, and carbon monoxide are generally well predicted for the whole range of equivalence ratios. The computational model also shows where the pollutants originate within the combustion chamber, thereby explaining the changes in the HC and CO emissions as a function of equivalence ratio. The results of this paper contribute to the understanding of the high emission behavior of HCCI engines at low equivalence ratios and are important for characterizing this previously little explored, yet important range of operation.
Date: February 20, 2004
Creator: Aceves, S. M.; Flowers, D. L.; Espinosa-Loza, F.; Martinez-Frias, J.; Dec, J. E.; Sjoberg, M. et al.
System: The UNT Digital Library