Restoring Sustainable Forests on Appalachian Mined Lands for Wood Products, Renewable Energy, Carbon Sequestration, and Other Ecosystems Services Quarterly Report (open access)

Restoring Sustainable Forests on Appalachian Mined Lands for Wood Products, Renewable Energy, Carbon Sequestration, and Other Ecosystems Services Quarterly Report

The overall purpose of this project is to evaluate the biological and economic feasibility of restoring high-quality forests on mined land, and to measure carbon sequestration and wood production benefits that would be achieved from forest restoration procedures. In this quarterly report, we present a preliminary comparison of the carbon sequestration benefits for two forest types used to convert abandoned grasslands for carbon sequestration. Annual mixed hardwood benefits, based on total stand carbon volume present at the end of a given year, range from a minimum of $0/ton of carbon to a maximum of $5.26/ton of carbon (low prices). White pine benefits based on carbon volume range from a minimum of $0/ton of carbon to a maximum of $18.61/ton of carbon (high prices). The higher maximum white pine carbon payment can primarily be attributed to the fact that the shorter rotation means that payments for white pine carbon are being made on far less cumulative carbon tonnage than for that of the long-rotation hardwoods. Therefore, the payment per ton of white pine carbon needs to be higher than that of the hardwoods in order to render the conversion to white pine profitable by the end of a rotation. These carbon …
Date: December 18, 2003
Creator: Burger, J.; Galbraith, J.; Fox, T.; Amacher, G.; Sullivan, J. & Zipper, C.
Object Type: Report
System: The UNT Digital Library
Silica Scale Management: Lowering Operating Costs through Improved Scale Control, and Adding Value by Extracting Marketable By-Products (open access)

Silica Scale Management: Lowering Operating Costs through Improved Scale Control, and Adding Value by Extracting Marketable By-Products

We are using laboratory and field experiments to design modeling tools and technology that will improve silica scale management practices in geothermal plants. Our work will help to lower operating costs through improved scale prediction and add new revenue streams from sale of mineral byproducts extracted from geothermal fluids. Improving the economics and effectiveness of scale control programs and/or extraction systems in geothermal operations requires a coupled kinetic-thermodynamic model of silica behavior. Silica scale precipitation is a multi-step process, involving a nucleation-related induction period, aqueous polymerization, condensation of polymers to form colloids, and deposition onto a solid surface. Many chemical and physical variables influence the rates of these steps and their impacts must be quantified and predictable in order to optimally control silica behavior. To date, in laboratory studies, we have quantified the effects on silica polymerization of the following set of chemical variables: Na at 500 and 2000 ppm, pH values from 5 to 9, temperatures of 25 and 50 C, and silica saturation values from 1.2 to 6 at initial dissolved silica concentrations of 600 ppm. Lowering pH both increases the induction time prior to polymerization and decreases the polymerization rate. We have successfully used a multiple regression …
Date: June 18, 2003
Creator: Burton, E. A.; Bourcier, W. L.; Wallce, A.; Bruton, C. J. & Leif, R.
Object Type: Article
System: The UNT Digital Library
Massively-Parallel Dislocation Dynamics Simulations (open access)

Massively-Parallel Dislocation Dynamics Simulations

Prediction of the plastic strength of single crystals based on the collective dynamics of dislocations has been a challenge for computational materials science for a number of years. The difficulty lies in the inability of the existing dislocation dynamics (DD) codes to handle a sufficiently large number of dislocation lines, in order to be statistically representative and to reproduce experimentally observed microstructures. A new massively-parallel DD code is developed that is capable of modeling million-dislocation systems by employing thousands of processors. We discuss the general aspects of this code that make such large scale simulations possible, as well as a few initial simulation results.
Date: June 18, 2003
Creator: Cai, W; Bulatov, V V; Pierce, T G; Hiratani, M; Rhee, M; Bartelt, M et al.
Object Type: Article
System: The UNT Digital Library
Final technical report on Award No. DE-FG02-92ER45465 (open access)

Final technical report on Award No. DE-FG02-92ER45465

The motivation of the previous program was to develop methods which could be used in a systematic study of the interface between glass and crystalline oxides. It was recognized that since the mechanical properties of glass-containing oxides are particularly important, it would be desirable to have a method which would also allow a systematic comparison of the mechanical properties of the materials. We found that the geometry of a glass film on a crystalline surface gave several new possibilities: we could develop methods for examining the mechanical properties of the films and the interfaces and we could examine both the crystallization of glass films and their wetting/dewetting behavior. Also, the samples are amenable to examination by the characterization techniques which give information on the chemistry and structure over a wide range of length scales: both chemistry and crystallography can be controlled and changes monitored.
Date: June 18, 2003
Creator: Carter, C. Barry
Object Type: Report
System: The UNT Digital Library
Mixed Electromagnetic and Circuit Simulations using Higher-Order Elements and Bases (open access)

Mixed Electromagnetic and Circuit Simulations using Higher-Order Elements and Bases

In this paper, an approach to couple higher-order electromagnetic surface integral equations to circuit simulations is presented. Terminals are defined that connect circuit elements to contacts modeled on the distributed electromagnetic domain. A modified charge-current continuity equation is proposed for a generalized KCL connection at the contacts. The distributive electromagnetic integral equations are developed using higher-order bases and elements that allow both better convergence and accuracy for modeling. The resulting scheme enables simultaneous solution of electromagnetic integral equations for arbitrarily-shaped objects and SPICE-like modeling for lumped circuits, and permits design iterations and visualization of the interaction between the two domains.
Date: June 18, 2003
Creator: Champagne, N J; Rockway, J D & Jandhyala, V
Object Type: Article
System: The UNT Digital Library
Geochemical Characterization Using Geophysical Data and Markov Chain Monte Carolo methods: A Case Study at the South Oyster Bacterial Transport Site in Virginia (open access)

Geochemical Characterization Using Geophysical Data and Markov Chain Monte Carolo methods: A Case Study at the South Oyster Bacterial Transport Site in Virginia

The spatial distribution of field-scale geochemical parameters, such as extractable Fe(II) and Fe(III), influences microbial processes and thus the efficacy of bioremediation. Because traditional characterization of those parameters is invasive and laborious, it is rarely performed sufficiently at the field-scale. Since both geochemical and geophysical parameters often correlate to some common physical properties (such as lithofacies), we investigated the utility of tomographic radar attenuation data for improving estimation of geochemical parameters using a Markov Chain Monte Carlo (MCMC) approach. The data used in this study included physical, geophysical, and geochemical measurements collected in and between several boreholes at the DOE South Oyster Bacterial Transport Site in Virginia. Results show that geophysical data, constrained by physical data, provided field-scale information about extractable Fe(II) and Fe(III) in a minimally invasive manner and with a resolution unparalleled by other geochemical characterization methods. This study presents our estimation framework for estimating Fe(II) and Fe(III), and its application to a specific site. Our hypothesis--that geochemical parameters and geophysical attributes can be linked through their mutual dependence on physical properties--should be applicable for estimating other geochemical parameters at other sites.
Date: November 18, 2003
Creator: Chen, Jinsong; Hubbard, Susan; Rubin, Yoram; Murray, Chris; Roden, Eric & Majer, Ernest
Object Type: Article
System: The UNT Digital Library
Handbook for operating a spectra-physics{trademark} quanta-ray pro-series Nd-YAG laser and MOPO-SL (master oscillator power oscillator) utilizing WinSpec{trademark} (open access)

Handbook for operating a spectra-physics{trademark} quanta-ray pro-series Nd-YAG laser and MOPO-SL (master oscillator power oscillator) utilizing WinSpec{trademark}

None
Date: October 18, 2003
Creator: Chen, Samuel Weisheng
Object Type: Report
System: The UNT Digital Library
Single Chain FV Constructs of Anti-Ganglioside GD2 Antibodies for Radioimaging and Radioimmunotherapy (open access)

Single Chain FV Constructs of Anti-Ganglioside GD2 Antibodies for Radioimaging and Radioimmunotherapy

Single chain FV constructs of anti-ganglioside GD2 antibodies for radioimaging
Date: March 18, 2003
Creator: Cheung, Nai-Kong
Object Type: Report
System: The UNT Digital Library
Ventilation Model and Analysis Report (open access)

Ventilation Model and Analysis Report

This model and analysis report develops, validates, and implements a conceptual model for heat transfer in and around a ventilated emplacement drift. This conceptual model includes thermal radiation between the waste package and the drift wall, convection from the waste package and drift wall surfaces into the flowing air, and conduction in the surrounding host rock. These heat transfer processes are coupled and vary both temporally and spatially, so numerical and analytical methods are used to implement the mathematical equations which describe the conceptual model. These numerical and analytical methods predict the transient response of the system, at the drift scale, in terms of spatially varying temperatures and ventilation efficiencies. The ventilation efficiency describes the effectiveness of the ventilation process in removing radionuclide decay heat from the drift environment. An alternative conceptual model is also developed which evaluates the influence of water and water vapor mass transport on the ventilation efficiency. These effects are described using analytical methods which bound the contribution of latent heat to the system, quantify the effects of varying degrees of host rock saturation (and hence host rock thermal conductivity) on the ventilation efficiency, and evaluate the effects of vapor and enhanced vapor diffusion on the …
Date: July 18, 2003
Creator: Chipman, V.
Object Type: Report
System: The UNT Digital Library
Dairy Policy Issues (open access)

Dairy Policy Issues

Many dairy farmer groups are concerned that imports of milk protein concentrates (MPCs) are displacing domestic dairy ingredients and thus depressing farm milk prices. S.560 and H.R. 1160 would impose tariff rate quotas on certain MPCs, and S. 40 would prohibit the use of dry MPC in domestic cheese production. Dairy processor groups are opposed to these bills. A dairy producer group challenged the Customs Service classification of MPCs, but Customs ruled that current classifications are correct.
Date: April 18, 2003
Creator: Chite, Ralph M.
Object Type: Report
System: The UNT Digital Library
Physical Property Models of Concentrated Cesium Eluate Solutions (open access)

Physical Property Models of Concentrated Cesium Eluate Solutions

Major analytes expected to be present in the WTP cesium ion-exchange eluate solutions were identified from the available analytical data collected during radioactive bench-scale runs, and a test matrix of cesium eluate solutions was designed within the bounding concentration ranges of those major analytes. A computer model describing the semi-batch evaporation of cesium eluate solutions was built using the Environmental Simulation Program (ESP), licensed by OLI Systems, Inc., and was run to calculate the physical properties of each test matrix solution concentrated to the target endpoints of 80 percent and 100 percent bulk saturation. The calculated physical properties were then analyzed statistically and fitted into predetermined mathematical expressions for the bulk solubility, density, viscosity and heat capacity as a function of temperature and feed concentration of each species considered in the matrix. In addition, the volume reduction factor, which is defined as the ratio of total cumulative feed volume to that of the initial acid charge, was calculated and modeled for the 80 percent saturation case. The R2 of the resulting physical property models ranged from 0.89 to 0.99. Validation of these physical property models against the true experimental data was not part of the current work scope; instead, the …
Date: June 18, 2003
Creator: Choi, A.S.
Object Type: Report
System: The UNT Digital Library
Clean Water Act Issues in the 108th Congress (open access)

Clean Water Act Issues in the 108th Congress

The Clean Water Act Issues has again received attention in the 108th Congress. At issue is how the federal government will assist states and cities in meeting needs to rebuild, repair, and upgrade wastewater treatment plants, especially in light of capital costs which are projected to be as much as $390 billion over the next two decades. In October 2004, the Senate Environment and Public Works Committee reported legislation to authorize $20 billion in funding for clean water infrastructure (S. 2550), while in July 2003, a House Transportation and Infrastructure subcommittee also approved a water infrastructure financing bill (H.R. 1560). Still, prospects for further action during the 108th Congress are uncertain.
Date: July 18, 2003
Creator: Copeland, Claudia
Object Type: Report
System: The UNT Digital Library
HIV/AIDS International Programs: Appropriations, FY2002-FY2004 (open access)

HIV/AIDS International Programs: Appropriations, FY2002-FY2004

This is a report on the administration's requests for international HIV/AIDS programs in the fiscal year 2004.
Date: July 18, 2003
Creator: Copson, Raymond W.
Object Type: Report
System: The UNT Digital Library
Thermophotovoltaic Arrays for Electrical Power Generation (open access)

Thermophotovoltaic Arrays for Electrical Power Generation

Sarnoff has designed an integrated array of thermophotovoltaic (TPV) cells based on the In(Al)GaAsSb/GaSb materials system. These arrays will be used in a system to generate electrical power from a radioisotope heat source that radiates at temperatures from 700 to 1000 C. Two arrays sandwich the slab heat source and will be connected in series to build voltage. Between the arrays and the heat source is a spectral control filter that transmits above-bandgap radiation and reflects below-bandgap radiation. The goal is to generate 5 mW of electrical power at 3 V from a 700 C radiant source. Sarnoff is a leader in antimonide-based TPV cell development. InGaAsSb cells with a bandgap of 0.53 eV have operated at system conversion efficiencies greater than 17%. The system included a front-surface filter, and a 905 C radiation source. The cells were grown via organo-metallic vapor-phase epitaxy. Sarnoff will bring this experience to bear on the proposed project. The authors first describe array and cell architecture. They then present calculated results showing that about 80 mW of power can be obtained from a 700 C radiator. Using a conservative array design, a 5-V output is possible.
Date: November 18, 2003
Creator: Corporation, Sarnoff
Object Type: Report
System: The UNT Digital Library
Tevatron separator beam impedance (open access)

Tevatron separator beam impedance

None
Date: March 18, 2003
Creator: Crisp, James L & Fellenz, Brian
Object Type: Report
System: The UNT Digital Library
Sudan: Humanitarian Crisis, Peace Talks, Terrorism, and U.S. Policy (open access)

Sudan: Humanitarian Crisis, Peace Talks, Terrorism, and U.S. Policy

None
Date: July 18, 2003
Creator: Dagne, Theodore S.
Object Type: Report
System: The UNT Digital Library
Development of a Cast Iron Fatigue Properties Database for use with Modern Design Methods (open access)

Development of a Cast Iron Fatigue Properties Database for use with Modern Design Methods

A reliable and comprehensive database of design properties for cast iron is key to full and efficient utilization of this versatile family of high production-volume engineering materials. A database of strain-life fatigue properties and supporting data for a wide range of structural cast irons representing industry standard quality was developed in this program. The database primarily covers ASTM/SAE standard structural grades of ADI, CGI, ductile iron and gray iron as well as an austempered gray iron. Twenty-two carefully chosen materials provided by commercial foundries were tested and fifteen additional datasets were contributed by private industry. The test materials are principally distinguished on the basis of grade designation; most grades were tested in a 25 mm section size and in a single material condition common for the particular grade. Selected grades were tested in multiple sections-sizes and/or material conditions to delineate the properties associated with a range of materials for the given grade. The cyclic properties are presented in terms of the conventional strain-life formalism (e.g., SAE J1099). Additionally, cyclic properties for gray iron and CGI are presented in terms of the Downing Model, which was specifically developed to treat the unique stress-strain response associated with gray iron (and to a …
Date: September 18, 2003
Creator: DeLa'O, James, D.; Gundlach, Richard, B. & Tartaglia, John, M.
Object Type: Report
System: The UNT Digital Library
Appropriations for FY2004: Legislative Branch (open access)

Appropriations for FY2004: Legislative Branch

Appropriations are one part of a complex federal budget process that includes budget resolutions, appropriations (regular, supplemental, and continuing) bills, rescissions, and budget reconciliation bills. This Report is a guide to one of the 13 regular appropriations bills that Congress passes each year. It is designed to supplement the information provided by the House and Senate Appropriations Subcommittees on Legislative Branch Appropriations.
Date: July 18, 2003
Creator: Dwyer, Paul E.
Object Type: Report
System: The UNT Digital Library
State Department and Related Agencies: FY2003 Appropriations and FY2004 Request (open access)

State Department and Related Agencies: FY2003 Appropriations and FY2004 Request

None
Date: July 18, 2003
Creator: Epstein, Susan B.
Object Type: Report
System: The UNT Digital Library
Coupled Geochemical and Hydrological Processes Governing the Fate and Transport of Radionuclides and Toxic Metals Beneath the Hanford Tank Farms (open access)

Coupled Geochemical and Hydrological Processes Governing the Fate and Transport of Radionuclides and Toxic Metals Beneath the Hanford Tank Farms

Provide an improved understanding of how preferential vertical and lateral flow, and the formation of immobile water influence the transport of radionuclides and toxic metals in heterogeneous, laminated sediments. Quantify the rates and mechanisms of radionuclide and toxic metal interaction with the solid phase under various hydrologic conditions. Provide new insights into how physical and mineralogical heterogeneities (e.g. stratification, pore regime connectivity, mineral composition along flowpaths) influence contaminant retardation and the degree of geochemical nonequilibrium during transport.
Date: July 18, 2003
Creator: Fendorf, Scott & Jardine, Phil
Object Type: Report
System: The UNT Digital Library
Automatic segmentation of histological structures in normal and neoplastic mammary gland tissue sections (open access)

Automatic segmentation of histological structures in normal and neoplastic mammary gland tissue sections

In this paper we present a scheme for real time segmentation of histological structures in microscopic images of normal and neoplastic mammary gland sections. Paraffin embedded or frozen tissue blocks are sliced, and sections are stained with hematoxylin and eosin (H&E). The sections are then imaged using conventional bright field microscopy. The background of the images is corrected by arithmetic manipulation using a ''phantom.'' Then we use the fast marching method with a speed function that depends on the brightness gradient of the image to obtain a preliminary approximation to the boundaries of the structures of interest within a region of interest (ROI) of the entire section manually selected by the user. We use the result of the fast marching method as the initial condition for the level set motion equation. We run this last method for a few steps and obtain the final result of the segmentation. These results can be connected from section to section to build a three-dimensional reconstruction of the entire tissue block that we are studying.
Date: January 18, 2003
Creator: Fernandez-Gonzalez, Rodrigo; Deschamps, Thomas; Idica, Adam K.; Malladi, Ravi & Ortiz de Solorzano, Carlos
Object Type: Article
System: The UNT Digital Library
Overview of Neutrino Factory Simulations. (open access)

Overview of Neutrino Factory Simulations.

Recent simulations have shown that muon cooling rings can effectively reduce both longitudinal and transverse emittance. The muon collaboration is investigating several varieties of muon cooling rings. This study looks at the first of these ring cooling scenarios that was proposed by V. Balbekov. This simulation of this ring shows significant cooling in the hard-edge field approximation. We discuss the status of using realistic fields in the tetra simulation.
Date: November 18, 2003
Creator: Fernow, R.C.
Object Type: Article
System: The UNT Digital Library
Efficient Multi-keV X-ray Sources from Ti-doped Aerogel Targets (open access)

Efficient Multi-keV X-ray Sources from Ti-doped Aerogel Targets

We have measured the production of h{nu} {approx}> 4.5 keV x-rays from low-density Ti-doped aerogel targets at the OMEGA laser facility (University of Rochester). The targets were 2.2 mm long by 2 mm diameter beryllium cylinders filled with Ti-doped (3 atomic percent) SiO{sub 2} foam. The doped-foam density was {approx} 3 mg/cc. Forty beams of the OMEGA laser ({gamma} = 351 nm) illuminated the two cylindrical faces of the target with a total power that ranged from 7 to 14 TW. The laser interaction fully ionizes the target (n{sub e}/n{sub crit} {approx}< 0.1), and allows the laser-bleaching wave to excite, supersonically, the high-Z emitter ions in the sample. The heating of the target was imaged with a gated (200 ps time resolution) x-ray framing camera filtered to observe > 4 keV. 2-D radiative hydrodynamic calculations predict rapid and uniform heating over the whole target volume with minimal energy losses into hydrodynamic motion. An x-ray streak camera, also filtered to observe > 4 keV, was used to measure the rate of heat propagation in the target. Ti K-shell x-ray emission was spectrally resolved with a two-channel crystal spectrometer and recorded with a set of calibrated aluminum x-ray diodes. Back-scattered laser energy …
Date: July 18, 2003
Creator: Fournier, K. B.; Constantin, C.; Poco, J.; Miller, M. C.; Back, C.; Suter, L. J. et al.
Object Type: Article
System: The UNT Digital Library
FIELD EVALUATION OF IMPROVED METHODS FOR MEASURING THE AIR LEAKAGE OF DUCT SYSTEMS UNDER NORMAL OPERATING CONDITIONS IN 51 HOMES (open access)

FIELD EVALUATION OF IMPROVED METHODS FOR MEASURING THE AIR LEAKAGE OF DUCT SYSTEMS UNDER NORMAL OPERATING CONDITIONS IN 51 HOMES

Duct leakage in forced-air distribution systems has been recognized for years as a major source of energy losses in residential buildings. Unfortunately, the distribution of leakage across homes is far from uniform, and measuring duct leakage under normal operating conditions has proven to be difficult. Recently, two new methods for estimating duct leakage at normal operating conditions have been devised. These are called the nulling test and the Delta-Q test. Small exploratory studies have been done to evaluate these tests, but previously no large-scale study on a broad variety of homes has been performed to determine the accuracy of these new methods in the field against an independent benchmark of leakage. This sort of study is important because it is difficult in a laboratory setting to replicate the range of leakage types found in real homes. This report presents the results of a study on 51 homes to evaluate these new methods relative to an independent benchmark and a method that is currently used. An evaluation of the benchmark procedure found that it worked very well for supply-side leakage measurements, but not as well on the return side. The nulling test was found to perform well, as long as wind …
Date: October 18, 2003
Creator: Francisco, Paul W.; Palmiter, Larry; Kruse, Erin & Davis, Bob
Object Type: Report
System: The UNT Digital Library