1996-2004 Trends in the Single-Family Housing Market: Spatial Analysis of the Residential Sector (open access)

1996-2004 Trends in the Single-Family Housing Market: Spatial Analysis of the Residential Sector

This report provides a detailed geographic analysis of two specific topics affecting the residential sector. First, we performed an analysis of new construction market trends using annual building permit data. We report summarized tables and national maps to help illustrate market conditions. Second, we performed a detailed geographic analysis of the housing finance market. We analyzed mortgage application data to provide citable statistics and detailed geographic summarization of the residential housing picture in the US for each year in the 1996-2004 period. The databases were linked to geographic information system tools to provide various map series detailing the results geographically. Looking at these results geographically may suggest potential new markets for TD programs addressing the residential sector that have not been considered previously. For example, we show which lenders affect which regions and which income or mortgage product classes. These results also highlight the issue of housing affordability. Energy efficiency R&D programs focused on developing new technology for the residential sector must be conscious of the costs of products resulting from research that will eventually impact the home owner or new home buyer. Results indicate that home values as a proportion of median family income in Building America communities are …
Date: September 5, 2006
Creator: Anderson, Dave M. & Elliott, Douglas B.
Object Type: Report
System: The UNT Digital Library
2004 Molecular and Ionic Clusters Gordon Conference - September 5-10, 2004 (open access)

2004 Molecular and Ionic Clusters Gordon Conference - September 5-10, 2004

This Report is Gordon Conference Molecular and Ionic Clusters Final Report and Agenda.
Date: September 5, 2004
Creator: Zwier, Timoty S.
Object Type: Article
System: The UNT Digital Library
2w Laser Propagation and Raman Backscatter in Underdense Gas Bag Plasmas (open access)

2w Laser Propagation and Raman Backscatter in Underdense Gas Bag Plasmas

Recent 2{omega} gasbag experiments on the Helen laser studied single-beam propagation and backscatter as a function of gas density. We present a comprehensive analysis of these experiments using simulations in HYDRA. Post-processed results agree well with experimental fast x-ray images (FXI) showing stable laser propagation across the bag. The measured total stimulated Raman backscatter (SRS) increases with initial gas density up to n{sub e} {approx} 0.08 n{sub c}, then decreases. Near-backscatter images (NBI) show that the decrease in total SRS with increasing density is not due to scatter outside of the collection optics. SRS gain spectra calculated from the HYDRA results agree well with experimental streak spectra. The tilt and spread in wavelength of the spectra appear to be explained by gasbag hydrodynamics only, with no need to invoke filamentation. Axial density gradients and laser pump absorption may combine to detune and limit SRS gain at high density.
Date: September 5, 2003
Creator: Meezan, N.; Divol, L.; Suter, L.; Miller, M.; Stevenson, R. M.; Slark, G. et al.
Object Type: Article
System: The UNT Digital Library
Abstract: Contaminant Travel Times From the Nevada Test Site to Yucca Mountain: Sensitivity to Porosity (open access)

Abstract: Contaminant Travel Times From the Nevada Test Site to Yucca Mountain: Sensitivity to Porosity

Yucca Mountain (YM), Nevada, has been proposed by the U.S. Department of Energy as a geologic repository for spent nuclear fuel and high-level radioactive waste. In this study, we investigate the potential for groundwater advective pathways from underground nuclear testing areas on the Nevada Test Site (NTS) to the YM area by estimating the timeframe for advective travel and its uncertainty resulting from porosity value uncertainty for hydrogeologic units (HGUs) in the region. We perform sensitivity analysis to determine the most influential HGUs on advective radionuclide travel times from the NTS to the YM area. Groundwater pathways and advective travel times are obtained using the particle tracking package MODPATH and flow results from the Death Valley Regional Flow System (DVRFS) model by the U.S. Geological Survey. Values and uncertainties of HGU porosities are quantified through evaluation of existing site porosity data and expert professional judgment and are incorporated through Monte Carlo simulations to estimate mean travel times and uncertainties. We base our simulations on two steady state flow scenarios for the purpose of long term prediction and monitoring. The first represents pre-pumping conditions prior to groundwater development in the area in 1912 (the initial stress period of the DVRFS model). …
Date: September 5, 2008
Creator: Pohlmann, Karl F.; Zhu, Jianting; Chapman, Jenny B.; Russell, Charles E.; Carroll, Rosemary W. H. & Shafer, David S.
Object Type: Article
System: The UNT Digital Library
Advanced Processing of CdTe- and CuIn{sub x}Ga{sub 1{minus}x}Se{sub 2}-Based Solar Cells; Phase I Report (open access)

Advanced Processing of CdTe- and CuIn{sub x}Ga{sub 1{minus}x}Se{sub 2}-Based Solar Cells; Phase I Report

The main tasks of the cadmium telluride portion of this project include the development of simplified processing for fabricating high-efficiency CdTe solar cells, studies on the long-term stability of CdTe devices, and the development of alternative transparent conducting oxides, window layers, and back contacts. The second portion of this project focused on CIGS solar cells. The main tasks include the development of a manufacturable process for CIGS devices and the development of high-band-gap alloys for use in tandem cell structures. Additional objectives include development of improved junction formation processing and contributing to the overall understanding of these materials and devices. Because the processing is manufacturing-driven, the authors use an all solid-state, simplified two-step process that relaxes the level of deposition control required.
Date: September 5, 2000
Creator: Morel, D. L. & Ferekides, C. S.
Object Type: Report
System: The UNT Digital Library
Air Conditioner Compressor Performance Model (open access)

Air Conditioner Compressor Performance Model

During the past three years, the Western Electricity Coordinating Council (WECC) Load Modeling Task Force (LMTF) has led the effort to develop the new modeling approach. As part of this effort, the Bonneville Power Administration (BPA), Southern California Edison (SCE), and Electric Power Research Institute (EPRI) Solutions tested 27 residential air-conditioning units to assess their response to delayed voltage recovery transients. After completing these tests, different modeling approaches were proposed, among them a performance modeling approach that proved to be one of the three favored for its simplicity and ability to recreate different SVR events satisfactorily. Funded by the California Energy Commission (CEC) under its load modeling project, researchers at Pacific Northwest National Laboratory (PNNL) led the follow-on task to analyze the motor testing data to derive the parameters needed to develop a performance models for the single-phase air-conditioning (SPAC) unit. To derive the performance model, PNNL researchers first used the motor voltage and frequency ramping test data to obtain the real (P) and reactive (Q) power versus voltage (V) and frequency (f) curves. Then, curve fitting was used to develop the P-V, Q-V, P-f, and Q-f relationships for motor running and stalling states. The resulting performance model ignores the …
Date: September 5, 2008
Creator: Lu, Ning; Xie, YuLong & Huang, Zhenyu
Object Type: Report
System: The UNT Digital Library
All Fiber Technology for High-Energy Petawatt Front End Laser Systems (open access)

All Fiber Technology for High-Energy Petawatt Front End Laser Systems

We are developing an all fiber front end for the next generation high-energy petawatt (HEPW) laser at Lawrence Livermore National Laboratory (LLNL). The ultimate goal of the LLNL HEPW effort is to generate 5-kJ pulses capable of compression to 5ps at 1053nm, enabling advanced x-ray backlighters and possible demonstration of fast ignition. We discuss the front-end of the laser design from the fiber master oscillator, which generates the mode-locked 20nm bandwidth initial pulses through the 10mJ output of the large flattened mode (LFM) fiber amplifier. Development of an all fiber front end requires technological breakthroughs in the key areas of the master oscillator and fiber amplification. Chirped pulse amplification in optical fibers has been demonstrated to 1mJ. Further increase is limited by the onset of stimulated Raman scattering (SRS). We have recently demonstrated a new flattened mode fiber technology, which reduces peak power for a given energy and thus the onset of SRS. Controlled experiments with 1st generation fibers yielded 0.5mJ of energy while significantly increasing the point at which nonlinear optical effects degrade the amplified pulse. In this paper we will discuss our efforts to extend this work to greater than 20mJ using our large flattened mode fiber amplifier.
Date: September 5, 2003
Creator: Dawson, J W; Liao, Z M; Jovanovic, I; Wattellier, B; Beach, R; Payne, S A et al.
Object Type: Article
System: The UNT Digital Library
Ambient Air Radionuclide Concentrations at and near TA-50 from 2003 through the First Quarter of 2004 (open access)

Ambient Air Radionuclide Concentrations at and near TA-50 from 2003 through the First Quarter of 2004

The Meteorology and Air Quality (MAQ) group at Los Alamos National Laboratory maintains and operates a large network of environmental air samplers called AIRNET. Some of these samplers are located near Material Disposal Area C at TA-50, a low-level radioactive waste burial site in the semiarid environment of the Pajarito Plateau, near Los Alamos. AIRNET sampling media consist of a filter and silica gel. They are exchanged once every 2 weeks. Presented are 5 months of air sampling results for 5 stations operating in the vicinity of Material Disposal Area C.
Date: September 5, 2005
Creator: Jacobson, Keith W. & Eberhart, Craig F.
Object Type: Report
System: The UNT Digital Library
Analysis of Constrained Optimization Variants of the Map-Seeking Circuit Algorithm (open access)

Analysis of Constrained Optimization Variants of the Map-Seeking Circuit Algorithm

The map-seeking circuit algorithm (MSC) was developed by Arathorn to efficiently solve the combinatorial problem of correspondence maximization, which arises in applications like computer vision, motion estimation, image matching, and automatic speech recognition [D. W. Arathorn, Map-Seeking Circuits in Visual Cognition: A Computational Mechanism for Biological and Machine Vision, Stanford University Press, 2002]. Given an input image, a template image, and a discrete set of transformations, the goal is to find a composition of transformations which gives the best fit between the transformed input and the template. We imbed the associated combinatorial search problem within a continuous framework by using superposition, and we analyze a resulting constrained optimization problem. We present several numerical schemes to compute local solutions, and we compare their performance on a pair of test problems: an image matching problem and the challenging problem of automatically solving a Rubik's cube.
Date: September 5, 2005
Creator: Harker, S.R.; Vogel, C.R. & Gedeon, T.
Object Type: Report
System: The UNT Digital Library
Approaches to Beam Stabilization in X-Band Linear Colliders (open access)

Approaches to Beam Stabilization in X-Band Linear Colliders

In order to stabilize the beams at the interaction point, the X-band linear collider proposes to use a combination of techniques: inter-train and intra-train beam-beam feedback, passive vibration isolation, and active vibration stabilization based on either accelerometers or laser interferometers. These systems operate in a technologically redundant fashion: simulations indicate that if one technique proves unusable in the final machine, the others will still support adequate luminosity. Experiments underway for all of these technologies have already demonstrated adequate performance.
Date: September 5, 2006
Creator: Frisch, Josef; Hendrickson, Linda; Himel, Thomas; Markiewicz, Thomas; Raubenheimer, Tor; Seryi, Andrei et al.
Object Type: Article
System: The UNT Digital Library
Biodiesel Handling and Use Guidelines (open access)

Biodiesel Handling and Use Guidelines

Placeholder for an out-of-date document.
Date: September 5, 2001
Creator: Tyson, S.
Object Type: Report
System: The UNT Digital Library
Biofuels for Your State: Helping the Economy and the Environment (open access)

Biofuels for Your State: Helping the Economy and the Environment

A fact sheet that describes the advantages of using ethanol and biodiesel to solve local problems such as smog, ozone, and carbon monoxide.
Date: September 5, 2001
Creator: Brown, H.
Object Type: Book
System: The UNT Digital Library
BSW Well Evaluation Report (open access)

BSW Well Evaluation Report

The BSW series wells are located in the Mixed Waste Management Facility and are part of the groundwater monitoring program at Savannah River Site. These wells have had persistent problems that prevent successful sampling that dates back to their installation. Only thirty-two of the fifty-three BSW wells were successfully sampled during 4th quarter, 2001. These problems were previously investigated by looking at field sampling logbooks from 4th quarter 2001 and other background information to try to identify causes for the high rate of sampling failure. Several possible causes were identified and reported in memorandum, SRT-EST-2002-00059. The memorandum recommended that an evaluation be performed on each well to identify problems and their causes and to correct them when possible. Environmental Restoration Division followed up on this recommendation and requested Savannah River Technology Center to perform an evaluation. This report includes the results of the evaluation performed on the BSW wells.
Date: September 5, 2002
Creator: Noonkester, J.V.
Object Type: Report
System: The UNT Digital Library
Characterization Activities to Determine the Extent of DNAPL in the Vadose Zone at the A-014 Outfall of A/M Area (open access)

Characterization Activities to Determine the Extent of DNAPL in the Vadose Zone at the A-014 Outfall of A/M Area

The purpose of this investigation was to perform characterization activities necessary to confirm the presence and extent of DNAPL in the shallow vadose zone near the headwaters of the A-014 Outfall. Following the characterization, additional soil vapor extraction wells and vadose monitoring probes were installed to promote and monitor remediation activities in regions of identified DNAPL.
Date: September 5, 2000
Creator: Jackson, D. G.
Object Type: Report
System: The UNT Digital Library
Characterization of high performance electrochemical systems for portable power. Final report for period September 15, 1993 - December 31, 2001 (open access)

Characterization of high performance electrochemical systems for portable power. Final report for period September 15, 1993 - December 31, 2001

The long-term objective of research has been to perform the enabling materials research necessary for the development of a battery oriented to the consumer market with special requirements in terms of safety, cycling life, and high specific energy and power. We have discovered novel processing of V{sub 2}O{sub 5} gels that leads to aerogel (ARG) and xerogel (XRG) films with specific energy and Li insertion capacity that are much higher than for other amorphous or crystalline forms of V{sub 2}O{sub 5}. We have also found that the new materials will host Mg{sup +2} and other cations which should be the basis for novel high-energy, high-power consumer battery systems. The investigation has examined (1) low-temperature synthesis of V{sub 2}O{sub 5} aerogel host materials, (2) characterization of insertion of Mg{sup 2+}, Zn{sup 2+}, and Al{sup 3+} into the V{sub 2}O{sub 5} hosts, (3) anode materials for the new systems, and alternate anode materials to replace the intrinsically unsafe lithium metal for lithium batteries, and (4) the feasibility of safer, nonaqueous, high-performance battery designs.
Date: September 5, 2002
Creator: Smyrl, W. H. & Owens, B. B.
Object Type: Report
System: The UNT Digital Library
Charged pion electroproduction on H,{sup 2}H, and {sup 3}He. (open access)

Charged pion electroproduction on H,{sup 2}H, and {sup 3}He.

None
Date: September 5, 2000
Creator: Jackson, H. E.
Object Type: Article
System: The UNT Digital Library
Combining Equations of State in Kull (open access)

Combining Equations of State in Kull

For ICF applications, the temperatures are hot enough that materials can transition to an atomic state or plasma. If we are simulating an ICF capsule, then either thru ALE, physical diffusion, transmutation by nuclear reactions, a mix model, or numerical diffusion (if we are running an Eulerian code), we will generate zones that contain multiple materials. It may be desired to treat certain mixtures of materials or mixed zones as atomic mixtures rather than as chunk mixtures. For example, suppose we have a deuterated material that is initially separated from a tritiated material. As these quantities come into contact at the atomic level, high energy neutrons will be generated from the D + T reaction. However, if we had a chunk of deuterium and a chunk of tritium in the same computational zone, then the D + T reaction would not take place. In dealing with atomic mixtures, two topics that immediately come to mind are mixed equations of state and mixed opacities. This report will only focus on the equation of state (EOS) aspect and its implementation in the Kull code. Imagine we have a zone that contains an atomic mixture of plastic and steel. If we know the …
Date: September 5, 2006
Creator: Ulitsky, M; Zimmerman, G & Renard, P
Object Type: Report
System: The UNT Digital Library
Comparison of MTI and Ground Truth Sea Surface Temperatures at Nauru (open access)

Comparison of MTI and Ground Truth Sea Surface Temperatures at Nauru

This report evaluates MTI-derived surface water temperature near the tropical Pacific island of Nauru. The MTI sea-surface temperatures were determined by the Los Alamos National Laboratory based on the robust retrieval.
Date: September 5, 2002
Creator: Kurzeja, R.
Object Type: Report
System: The UNT Digital Library
Compilation of Data on Radionuclide Data for Specific Activity, Specific Heat and Fission Product Yields (open access)

Compilation of Data on Radionuclide Data for Specific Activity, Specific Heat and Fission Product Yields

This compilation was undertaken to update the data used in calculation of curie and heat loadings of waste containers in the Solid Waste Management Facility. The data has broad general use and has been cross-checked extensively in order to be of use in the Materials Accountability arena. The fission product cross-sections have been included because they are of use in the Environmental Remediation and Waste Management areas where radionuclides which are not readily detectable need to be calculated from the relative fission yields and material dispersion data.
Date: September 5, 2000
Creator: Gibbs, A. & Thomason, R.S.
Object Type: Report
System: The UNT Digital Library
The complete genome sequence of Staphylothermus marinus reveals differences in sulfur metabolism among heterotrophic Crenarchaeota (open access)

The complete genome sequence of Staphylothermus marinus reveals differences in sulfur metabolism among heterotrophic Crenarchaeota

Staphylothermus marinus is an anaerobic, sulfur-reducing peptide fermenter of the archaeal phylum Crenarchaeota. It is the third heterotrophic, obligate sulfur reducing crenarchaeote to be sequenced and provides an opportunity for comparative analysis of the three genomes. The 1.57 Mbp genome of the hyperthermophilic crenarchaeote Staphylothermus marinus has been completely sequenced. The main energy generating pathways likely involve 2-oxoacid:ferredoxin oxidoreductases and ADP-forming acetyl-CoA synthases. S. marinus possesses several enzymes not present in other crenarchaeotes including a sodium ion-translocating decarboxylase likely to be involved in amino acid degradation. S. marinus lacks sulfur-reducing enzymes present in the other two sulfur-reducing crenarchaeotes that have been sequenced - Thermofilum pendens and Hyperthermus butylicus. Instead it has three operons similar to the mbh and mbx operons of Pyrococcus furiosus, which may play a role in sulfur reduction and/or hydrogen production. The two marine organisms, S. marinus and H. butylicus, possess more sodium-dependent transporters than T. pendens and use symporters for potassium uptake while T. pendens uses an ATP-dependent potassium transporter. T. pendens has adapted to a nutrient-rich environment while H. butylicus is adapted to a nutrient-poor environment, and S. marinus lies between these two extremes. The three heterotrophic sulfur-reducing crenarchaeotes have adapted to their habitats, terrestrial …
Date: September 5, 2008
Creator: Anderson, iain J.; Dharmarajan, Lakshmi; Rodriguez, Jason; Hooper, Sean; Porat, Iris; Ulrich, Luke E. et al.
Object Type: Article
System: The UNT Digital Library
Comprehensive Approaches to Multiphase Flows in Geophysics - Application to nonisothermal, nonhomogenous, unsteady, large-scale, turbulent dusty clouds I. Hydrodynamic and Thermodynamic RANS and LES Models (open access)

Comprehensive Approaches to Multiphase Flows in Geophysics - Application to nonisothermal, nonhomogenous, unsteady, large-scale, turbulent dusty clouds I. Hydrodynamic and Thermodynamic RANS and LES Models

The objective of this manuscript is to fully derive a geophysical multiphase model able to ''accommodate'' different multiphase turbulence approaches; viz., the Reynolds Averaged Navier-Stokes (RANS), the Large Eddy Simulation (LES), or hybrid RANSLES. This manuscript is the first part of a larger geophysical multiphase project--lead by LANL--that aims to develop comprehensive modeling tools for large-scale, atmospheric, transient-buoyancy dusty jets and plume (e.g., plinian clouds, nuclear ''mushrooms'', ''supercell'' forest fire plumes) and for boundary-dominated geophysical multiphase gravity currents (e.g., dusty surges, diluted pyroclastic flows, dusty gravity currents in street canyons). LES is a partially deterministic approach constructed on either a spatial- or a temporal-separation between the large and small scales of the flow, whereas RANS is an entirely probabilistic approach constructed on a statistical separation between an ensemble-averaged mean and higher-order statistical moments (the so-called ''fluctuating parts''). Within this specific multiphase context, both turbulence approaches are built up upon the same phasic binary-valued ''function of presence''. This function of presence formally describes the occurrence--or not--of any phase at a given position and time and, therefore, allows to derive the same basic multiphase Navier-Stokes model for either the RANS or the LES frameworks. The only differences between these turbulence frameworks are …
Date: September 5, 2005
Creator: Dartevelle, S.
Object Type: Report
System: The UNT Digital Library
Concentric Titled Double-Helix Dipole Magnets (open access)

Concentric Titled Double-Helix Dipole Magnets

The high magnetic fields required for future accelerator magnets can only be achieved with Nb3Sn, other A15 or HTS type conductors, which are brittle and sensitive to mechanical strain. The traditional ''cosine-theta'' dipole configuration has intrinsic drawbacks that make it difficult and expensive to employ such conductors in these designs. Some of these problems involve (1) difficulty in applying enough pre-stress to counteract Lorentz forces without compromising conductor performance; (2) small minimum bend radii of the conductor necessitating the intricate wind-and-react coil fabrication; (3) complex spacers in particular for coil ends and expensive tooling for coil fabrication; (4) typically only 2/3 of the coil aperture can be used with achievable field uniformity.
Date: September 5, 2003
Creator: Meinke, Rainer; Goodzeit, Carl & Ball, Millicent
Object Type: Report
System: The UNT Digital Library
Demonstration of an improved subfilter stress closure for WRF (open access)

Demonstration of an improved subfilter stress closure for WRF

None
Date: September 5, 2007
Creator: Mirocha, J D; Lundquist, J K; Chow, F K & Lundquist, K A
Object Type: Article
System: The UNT Digital Library
A density functional theory study of the oxidation of methanol to formaldehyde over vanadia supported on silica, titania, and zirconia (open access)

A density functional theory study of the oxidation of methanol to formaldehyde over vanadia supported on silica, titania, and zirconia

Density functional theory was used to investigate the mechanism and kinetics of methanol oxidation to formaldehyde over vanadia supported on silica, titania, and zirconia. The catalytically active site was modeled as an isolated VO{sub 4} unit attached to the support. The calculated geometry and vibrational frequencies of the active site are in good agreement with experimental measurements both for model compounds and oxide-supported vanadia. Methanol adsorption is found to occur preferentially with the rupture of a V-O-M bond (M = Si, Ti, Zr) and with preferential attachment of a methoxy group to V. The vibrational frequencies of the methoxy group are in good agreement with those observed experimentally as are the calculated isobars. The formation of formaldehyde is assumed to occur via the transfer of an H atom of a methoxy group to the O atom of the V=O group. The activation energy for this process is found to be in the range of 199-214 kJ/mol and apparent activation energies for the overall oxidation of methanol to formaldehyde are predicted to lie in the range of 112-123 kJ/mol, which is significantly higher than that found experimentally. Moreover, the predicted turnover frequency (TOF) for methanol oxidation is found to be essentially …
Date: September 5, 2002
Creator: Khaliullin, Rustam Z. & Bell, Alexis T.
Object Type: Article
System: The UNT Digital Library