MINIMIZING NET CO2 EMISSIONS BY OXIDATIVE CO-PYROLYSIS OF COAL / BIOMASS BLENDS (open access)

MINIMIZING NET CO2 EMISSIONS BY OXIDATIVE CO-PYROLYSIS OF COAL / BIOMASS BLENDS

This study presents a set of thermodynamic calculations on the optimal mode of solid fuel utilization considering a wide range of fuel types and processing technologies. The technologies include stand-alone combustion, biomass/coal cofiring, oxidative pyrolysis, and straight carbonization with no energy recovery but with elemental carbon storage. The results show that the thermodynamically optimal way to process solid fuels depends strongly on the specific fuels and technologies available, the local demand for heat or for electricity, and the local baseline energy-production method. Burning renewable fuels reduces anthropogenic CO{sub 2} emissions as widely recognized. In certain cases, however, other processing methods are equally or more effective, including the simple carbonization or oxidative pyrolysis of biomass fuels.
Date: December 23, 2001
Creator: Lang, Todd & Hurt, Robert
Object Type: Report
System: The UNT Digital Library
Accuracy of the Quasistatic Method for Two-Dimensional Thermal Reactor Transients with Feedback (open access)

Accuracy of the Quasistatic Method for Two-Dimensional Thermal Reactor Transients with Feedback

An important aspect in the design and safe operation of a nuclear reactor is the behavior of a reactor in a transient, or nonsteady state, condition. This study shows that the quasistatic method is capable of producing highly accurate results, relative to the direct finite-difference method, for two-dimensional thermal reactor transients with feedback.
Date: October 23, 2001
Creator: Dodds, H.L. Jr.
Object Type: Article
System: The UNT Digital Library
The charm quark mass to two-loop order (open access)

The charm quark mass to two-loop order

The truncation of the perturbative series at one loop order for the mass renormalization constants remain a significant systematic uncertainty in the determination of heavy quark masses in lattice QCD. We present here a high beta Monte Carlo calculation of the two loop mass renormalization constant for clover-improved fermions near the charm mass in the Fermilab heavy quark formalism. A preliminary value for the charm quark mass in the {ovr MS} scheme at two loop order is reported.
Date: October 23, 2001
Creator: Juge, Keisuke Jimmy
Object Type: Article
System: The UNT Digital Library
Computational Modeling in Support of National Ignition Facility Operations (open access)

Computational Modeling in Support of National Ignition Facility Operations

Numerical simulation of the National Ignition Facility (NIF) laser performance and automated control of laser setup process are crucial to the project's success. These functions will be performed by two closely coupled computer codes: the virtual beamline (VBL) and the laser operations performance model (LPOM).
Date: October 23, 2001
Creator: Shaw, M J; Sacks, R A; Haynam, C A & Williams, W H
Object Type: Article
System: The UNT Digital Library
Current trends in scintillator detectors and materials (open access)

Current trends in scintillator detectors and materials

The last decade has seen a renaissance in inorganic scintillator development for gamma ray detection. Lead tungstate (PbWO4) has been developed for high energy physics experiments, and possesses exceptionally high density and radiation hardness, albeit with low luminous efficiency. Lutetium orthosilicate or LSO (Lu2SiO5:Ce) possesses a unique combination of high luminous efficiency, high density, and reasonably short decay time, and is now incorporated in commercial positron emission tomography (PET) cameras. There have been advances in understanding the fundamental mechanisms that limit energy resolution, and several recently discovered materials (such as LaBr3:Ce) possess energy resolution that approaches that of direct solid state detectors. Finally, there are indications that a neglected class of scintillator materials that exhibit near band-edge fluorescence could provide scintillators with sub-nanosecond decay times and high luminescent efficiency.
Date: October 23, 2001
Creator: Moses, William W.
Object Type: Article
System: The UNT Digital Library
Determination of Parts-Per-Million Cesium in Simulated Nuclear Waste with the Cesium-Selective Electrode (open access)

Determination of Parts-Per-Million Cesium in Simulated Nuclear Waste with the Cesium-Selective Electrode

Because the molybdophosphate electrode was not sufficiently sensitive, and the reliability of the ''liquid state'' electrode for routine analysis was uncertain, a cesium-selective electrode of the proven liquid membrane type was developed. This paper describes preparation and testing of a liquid membrane electrode that contains cesium tetraphenylboron dissolved in 4-ethylnitrobenzene.
Date: October 23, 2001
Creator: Baumann, E. W.
Object Type: Article
System: The UNT Digital Library
A DTA, TGA, and Metallurgical Study of the Exothermic Reactions Between Aluminum and Uranium Compounds: The Solid State Reactions of Uranium Oxides and Uranates with Aluminum (open access)

A DTA, TGA, and Metallurgical Study of the Exothermic Reactions Between Aluminum and Uranium Compounds: The Solid State Reactions of Uranium Oxides and Uranates with Aluminum

Because recent experience at the Savannah River Plant revealed the pseudo-hexagonal uranates Na2U2O7 and Na6U7O2 will react exothermically in the solid state with aluminum, a systematic thermal study of the aluminothermic reactions of the three crystal classes of uranates and their relationships was begun at the Savannah River Laboratory. This paper discusses that study.
Date: October 23, 2001
Creator: Gray, L.W.
Object Type: Article
System: The UNT Digital Library
Ductile Fracture of Cracked Steel Plates (open access)

Ductile Fracture of Cracked Steel Plates

A simple relationship between loading for crack initiation, or onset of ductile tear, and crack length is presented for center-cracked plates of mild steel. Formulation of the nonlinear boundary-value problem is based on incremental theory of plasticity for Prandtl-Reuss materials. Quasi-static solutions corresponding to a series of incremental loading conditions are obtained by the method of finite elements. Tests conducted on plates of two types of mild steel agree with numerical results.
Date: October 23, 2001
Creator: Yau, W. F.
Object Type: Article
System: The UNT Digital Library
E1 Working Group Summary: Neutrino factories and muon colliders (open access)

E1 Working Group Summary: Neutrino factories and muon colliders

We are in the middle of a time of exciting discovery, namely that neutrinos have mass and oscillate. In order to take the next steps to understand this potential window onto what well might be the mechanism that links the quarks and leptons, we need both new neutrino beams and new detectors. The new beamlines can and should also provide new laboratories for doing charged lepton flavor physics, and the new detectors can and should also provide laboratories for doing other physics like proton decay, supernovae searches, etc. The new neutrino beams serve as milestones along the way to a muon collider, which can answer questions in yet another sector of particle physics, namely the Higgs sector or ultimately the energy frontier. In this report we discuss the current status of neutrino oscillation physics, what other oscillation measurements are needed to fully explore the phenomenon, and finally, what other new physics can be explored as a result of building of these facilities.
Date: October 23, 2001
Creator: al., Todd Adams et
Object Type: Article
System: The UNT Digital Library
ENDF/B Thermal Data Testing (open access)

ENDF/B Thermal Data Testing

The thermal data testing group is concerned with establishing the merit of ENDF/B cross sections for the analysis of thermal systems. The integral experiments used in the testing are designed to analyze each of the phenomena identified in the familiar four-factor formula. For brevity, only the testing of the cross sections in uranium systems is described in this report.
Date: October 23, 2001
Creator: McCrosson, F.J.
Object Type: Report
System: The UNT Digital Library
Equilibrium and Kinetic Studies of Systems of Hydrogen Isotopes, Lithium Hydrides, Aluminum and LiAlO2 (open access)

Equilibrium and Kinetic Studies of Systems of Hydrogen Isotopes, Lithium Hydrides, Aluminum and LiAlO2

This paper described measurements of (1) the distribution of tritium and helium throughout both phases of irradiated Li-Al alloy, (2) the migration rate of tritium during moderate heating, (3) equilibrium pressures as functions of temperature of H2, D2, or T2 in contact with lithium hydrides + aluminum, Li-Al alloy, or irradiated Li-Al alloy, (4) the equilibrium constant for the reaction as a function of temperature, and (5) extraction rates of tritium from irradiated LiAlO2 targets at elevated temperatures.
Date: October 23, 2001
Creator: Owen, J.H.
Object Type: Article
System: The UNT Digital Library
Final technical report for Interagency Agreement No. DE-AI02-98ER62683: Development of a functional genomics approach to use radiation-induced changes in gene expression to monitor for low dose and low dose-rate exposures (open access)

Final technical report for Interagency Agreement No. DE-AI02-98ER62683: Development of a functional genomics approach to use radiation-induced changes in gene expression to monitor for low dose and low dose-rate exposures

Microarray analysis and other molecular biology techniques were used to investigate the regulation of gene expression following ionizing radiation exposure.
Date: October 23, 2001
Creator: Albert J. Fornace, Jr.
Object Type: Report
System: The UNT Digital Library
Gas Pressure Forming of Titanium Alloys and Composites by Transformation Superplasticity (open access)

Gas Pressure Forming of Titanium Alloys and Composites by Transformation Superplasticity

By thermally cycling through their transformation temperature range, coarse-grained, polymorphic materials can be deformed superplastically, owing to the emergence of transformation mismatch plasticity (or transformation superplasticity) as a deformation mechanism. This mechanism is investigated under biaxial stress conditions during thermal cycling of unalloyed titanium, Ti-6Al-4V, and their composites (Ti/10 vol.% TiC{sub p}, Ti-6Al-4V/10 vol% TiC{sub p} and Ti-6Al-4V/5 vol.% TiB{sub w}). During gas-pressure dome bulging experiments, the dome height was measured as a function of forming time. Adapting existing models of biaxial doming to the case of transformation superplasticity where the strain-rate sensitivity is unity, we verify the operation of this deformation mechanism in all experimental materials, and compare the biaxial results to uniaxial thermal cycling results on the same materials. Finally, existing thickness distribution models are compared with experimentally measured profiles.
Date: October 23, 2001
Creator: Frary, M; Schuh, C & Dunand, D C
Object Type: Article
System: The UNT Digital Library
Highly improved naive and staggered fermions (open access)

Highly improved naive and staggered fermions

We present a new action for highly improved staggered fermions. We show that perturbative calculations for the new action are well-behaved where those of the conventional staggered action are badly behaved. We discuss the effects of the new terms in controlling flavor mixing, and discuss the design of operators for the action.
Date: October 23, 2001
Creator: al., Howard D. Trottier et
Object Type: Article
System: The UNT Digital Library
Hydrogen Transport in Copper (open access)

Hydrogen Transport in Copper

Hydrogen interaction with oxygen in copper exerts a significant influence on the apparent hydrogen diffusivity and the quantity of hydrogen absorbed. Correlation of the amount of absorbed tritium with oxygen content and dependence of permeation transients on both oxygen content and prior treatment indicate that both reversible and irreversible interactions occur between hydrogen and dissolved oxygen. This paper discusses results of that study.
Date: October 23, 2001
Creator: Caskey, G. R., Jr.
Object Type: Article
System: The UNT Digital Library
HyperCP at Fermilab -- A status report (open access)

HyperCP at Fermilab -- A status report

The primary purpose of the HyperCP experiment at Fermilab is to test CP in hyperon decays by comparing the alpha parameters for {Xi}{sup -} and {Xi}{sup +} decays in the decay sequence: {Xi}{sup -} {yields} {pi} + {Lambda}{sup 0}, {Lambda}{sup 0} {yields} {pi}{sup -} + p. In addition, we can test CP in charged kaon decays by comparing the slopes of the Dalitz plot for K{sup +} and K{sup -} decays. They are also looking at rare decay modes of charged kaons and hyperons, particularly those involving muons.
Date: October 23, 2001
Creator: al., M. J. Longo et
Object Type: Article
System: The UNT Digital Library
Method to regenerate ammonia for the capture of carbon dioxide (open access)

Method to regenerate ammonia for the capture of carbon dioxide

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Date: October 23, 2001
Creator: Huang, Houping; Chang, Shih-Ger & Dorchak, Thomas
Object Type: Article
System: The UNT Digital Library
Midwest Superconductivity Consortium - Final Progress Report October 2001 (open access)

Midwest Superconductivity Consortium - Final Progress Report October 2001

The basic mission of the Consortium was to advance the science and understanding of high-T{sub c} superconductivity and to promote the development of new materials and improved processing technology. Focused group efforts were the key element of the research program. One program area is the understanding of the layered structures involved in candidate materials and the factors that control their formation, stability and relationship superconductor properties. The other program area had a focus upon factors that limit or control the transport properties such as weak links, flux lattice behavior, and interfaces. Interactions among Consortium d with industrial armiates were an integral part of the program.
Date: October 23, 2001
Creator: Bement, Arden L.
Object Type: Report
System: The UNT Digital Library
Procedure for Determining Leachabilities of Radioactive Waste Forms (open access)

Procedure for Determining Leachabilities of Radioactive Waste Forms

Integrity and durability of solid radioactive wastes are related principally to rates at which waste constituents are leached into environmental water. This paper discusses a new and improved procedure which was developed for determining leachabilities of proposed radioactive waste forms. While no laboratory procedure can be expected to duplicate all possible environmental conditions, a single test is desirable to compare the leaching properties of solid waste forms produced in different laboratories.
Date: October 23, 2001
Creator: Kelley, J. A. & Wallace, R. M.
Object Type: Article
System: The UNT Digital Library
Small scale anisotropies of UHECRs from super-heavy halo dark matter (open access)

Small scale anisotropies of UHECRs from super-heavy halo dark matter

The decay of very heavy metastable relics of the Early Universe can produce ultra-high energy cosmic rays (UHECRs) in the halo of our own Galaxy. In this model, no Greisen-Zatsepin-Kuzmin cutoff is expected because of the short propagation distances. They show here that, as a consequence of the hierarchical build up of the halo, this scenario predicts the existence of small scale anisotropies in the arrival directions of UHECRs, in addition to a large scale anisotropy, known from previous studies. They also suggest some other observable consequences of this scenario which will be testable with upcoming experiments, as Auguer, EUSO and OWL.
Date: October 23, 2001
Creator: Blasi, P. & Sheth, R. K.
Object Type: Article
System: The UNT Digital Library
Some Features of Transverse Instability of Partly Compensated Proton Beams (open access)

Some Features of Transverse Instability of Partly Compensated Proton Beams

suppression of generation and accumulation of secondary particles is a traditional method for suppression the transverse electron-proton instability: improve the vacuum, use a gap in beam for electron removing, use cleaning electrodes, suppressing secondary emission. But opposite solution is also possible. Transverse e-p instability in proton rings can be damped by increasing beam density and the rate of secondary particles generation above a threshold level, with decrease of the unstable wavelength below a transverse beam size. In high current Proton Storage Rings (PSR) such as, the LANSCE PSR it is possible to reach this island of stability by multiturn, concentrated charge exchange injection without painting and by enhanced generation of secondary plasma. This possibility was demonstrated in smaller scale PSR at the INP, Novosibirisk [1]. Damping of the e-p instability allowed to accumulate a coasting, space charge compensated, circulating proton beam with intensity, corresponding to the Laslett tune shift of {Delta}{nu} = 5 in the ring with original tune of {nu} = 0.85. In the other PSR transverse instability of bunched beam was damped by a simple feed back [2,3]. In this article they discuss experimental observations of transverse instability of proton beams in different accelerators and storage rings and …
Date: October 23, 2001
Creator: Dudnikov, Vadim
Object Type: Article
System: The UNT Digital Library
ULTRA-LIGHTWEIGHT CEMENT (open access)

ULTRA-LIGHTWEIGHT CEMENT

The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). Work reported herein addresses tasks performed in the fourth quarter as well as the other three quarters of the past year. The subjects that were covered in previous reports and that are also discussed in this report include: Analysis of field laboratory data of active cement applications from three oil-well service companies; Preliminary findings from a literature review focusing on problems associated with ultra-lightweight cements; Summary of pertinent information from Russian ultra-lightweight cement literature review; and Comparison of compressive strengths of ULHS systems using ultrasonic and crush methods Results reported from the fourth quarter include laboratory testing of ULHS systems along with other lightweight cement systems--foamed and sodium silicate slurries. These comparison studies were completed for two different densities (10.0 and 11.5 lb/gal) and three different field application scenarios. Additional testing included the mechanical properties of ULHS systems and other lightweight systems. Studies were also performed to examine the effect that circulation by centrifugal pump during mixing has on breakage of ULHS.
Date: October 23, 2001
Creator: Sabins, Fred
Object Type: Report
System: The UNT Digital Library
Zone of Interaction Between Hanford Site Groundwater and Adjacent Columbia River (open access)

Zone of Interaction Between Hanford Site Groundwater and Adjacent Columbia River

This report describes the FY 2000 results of a Science and Technology investigation of the groundwater/river interface at the Hanford Site. The investigation focused on (1) a 2-D simulation of water flowpaths beneath the shoreline region under the influence of a transient river stage, and (2) mixing between groundwater and river water.
Date: October 23, 2001
Creator: Peterson, Robert E. & Connelly, Michael P.
Object Type: Report
System: The UNT Digital Library
Zone of Interaction Between Hanford Site Groundwater and Adjacent Columbia River (open access)

Zone of Interaction Between Hanford Site Groundwater and Adjacent Columbia River

This report describes the FY 2000 results of a Science and Technology investigation of the groundwater/river interface at the Hanford Site. The investigation focused on (1) a 2-D simulation of water flowpaths beneath the shoreline region under the influence of a transient river stage, and (2) mixing between groundwater and river water.
Date: October 23, 2001
Creator: Peterson, Robert E.
Object Type: Report
System: The UNT Digital Library