ACTION CONCENTRATION FOR MIXTURES OF VOLATILE ORGANIC COMPOUNDS (VOC) & METHANE & HYDROGEN (open access)

ACTION CONCENTRATION FOR MIXTURES OF VOLATILE ORGANIC COMPOUNDS (VOC) & METHANE & HYDROGEN

Waste containers may contain volatile organic compounds (VOCs), methane, hydrogen and possibly propane. These constituents may occur individually or in mixtures. Determining if a waste container contains a flammable concentration of flammable gases and vapors (from VOCs) is important to the safety of the handling, repackaging and shipping activities. This report provides the basis for determining the flammability of mixtures of flammable gases and vapors. The concentration of a mixture that is at the lowest flammability limit for that mixture is called the action concentration. The action concentration can be determined using total VOC concentrations or actual concentration of each individual VOC. The concentrations of hydrogen and methane are included with the total VOC or individual VOC concentration to determine the action concentration. Concentrations below this point are not flammable. Waste containers with gas/vapor concentrations at or above the action concentration are considered flammable.
Date: July 10, 2006
Creator: MARUSICH, R.M.
Object Type: Report
System: The UNT Digital Library
Electron Amplification in Diamond. (open access)

Electron Amplification in Diamond.

We report on recent progress toward development of secondary emission ''amplifiers'' for photocathodes. Secondary emission gain of over 300 has been achieved in transmission mode and emission mode for a variety of diamond samples. Techniques of sample preparation, including hydrogenation to achieve negative electron affinity (NEA), have been adapted to this application.
Date: July 10, 2006
Creator: Smedley, J.; Ben-Zvi, Ilan; Burrill, A.; Chang, X.; Grimes, J.; Rao, T. et al.
Object Type: Article
System: The UNT Digital Library
DEUTERIUM, TRITIUM, AND HELIUM DESORPTION FROM AGED TITANIUM TRITIDES. PART I. (open access)

DEUTERIUM, TRITIUM, AND HELIUM DESORPTION FROM AGED TITANIUM TRITIDES. PART I.

Six new samples of tritium-aged bulk titanium have been examined by thermal desorption and isotope exchange chemistry. The discovery of a lower temperature hydrogen desorption state in these materials, previously reported, has been confirmed in one of the new samples. The helium release of the samples shows the more severe effects obtained from longer aging periods, i.e. higher initial He/M ratios. Several of the more aged samples were spontaneously releasing helium. Part I will discuss the new results on the new lower temperature hydrogen desorption state found in one more extensively studied sample. Part II will discuss the hydrogen/helium release behavior of the remaining samples.
Date: July 10, 2006
Creator: Shanahan, K & Jeffrey Holder, J
Object Type: Article
System: The UNT Digital Library
"Assistance to States on Geothermal Energy" (open access)

"Assistance to States on Geothermal Energy"

This final report summarizes work carried out under agreement with the U.S. Department of Energy, related to geothermal energy policy issues. This project has involved a combination of outreach and publications on geothermal energy—Contract Number DE-FG03-01SF22367—with a specific focus on educating state-level policymakers. Education of state policymakers is vitally important because state policy (in the form of incentives or regulation) is a crucial part of the success of geothermal energy. State policymakers wield a significant influence over all of these policies. They are also in need of high quality, non-biased educational resources which this project provided. This project provided outreach to legislatures, in the form of responses to information requests on geothermal energy and publications. The publications addressed: geothermal leasing, geothermal policy, constitutional and statutory authority for the development of geothermal district energy systems, and state regulation of geothermal district energy systems. These publications were distributed to legislative energy committee members, and chairs, legislative staff, legislative libraries, and other related state officials. The effect of this effort has been to provide an extensive resource of information about geothermal energy for state policymakers in a form that is useful to them. This non-partisan information has been used as state policymakers attempt …
Date: July 10, 2006
Creator: Sikkema, Linda & DeCesaro, Jennifer
Object Type: Report
System: The UNT Digital Library
High Energy Neutrinos and Cosmic-Rays From Low-Luminosity Gamma-Ray Bursts? (open access)

High Energy Neutrinos and Cosmic-Rays From Low-Luminosity Gamma-Ray Bursts?

The recently discovered gamma-ray burst (GRB) 060218/SN 2006aj is classified as an X-ray Flash with very long duration driven possibly by a neutron star. Since GRB 060218 is very near {approx} 140 Mpc and very dim, one-year observation by Swift suggests that the true rate of GRB 060218-like events might be very high so that such low luminosity GRBs (LL-GRBs) might form a different population of GRBs from the cosmological high luminosity GRBs (HL-GRBs). We found that the high energy neutrino background from such LL-GRBs could be comparable with or larger than that from HL-GRBs. If each neutrino event is detected by IceCube, later optical-infrared follow-up observations such as by Subaru could identify a Type Ibc supernova associated with LL-GRBs, even if gamma- and X-rays are not observed by Swift. This is in a sense a new window from neutrino astronomy, which might enable us to confirm the existence of LL-GRBs and to obtain information about their rate and origin. We also argue LL-GRBs as high energy gamma-ray and cosmic-ray sources.
Date: July 10, 2006
Creator: Murase, Kohta; /Kyoto U., Yukawa Inst., Kyoto; Ioka, Kunihito; U., /Kyoto; Nagataki, Shigehiro; /Kyoto U., Yukawa Inst., Kyoto /KIPAC, Menlo Park et al.
Object Type: Report
System: The UNT Digital Library
Mitigating Carbon Emissions: the Potential of Improving Efficiencyof Household Appliances in China (open access)

Mitigating Carbon Emissions: the Potential of Improving Efficiencyof Household Appliances in China

China is already the second's largest energy consumer in the world after the United States, and its demand for energy is expected to continue to grow rapidly in the foreseeable future, due to its fast economic growth and its low level of energy use per capita. From 2001 to 2005, the growth rate of energy consumption in China has exceeded the growth rate of its economy (NBS, 2006), raising serious concerns about the consequences of such energy use on local environment and global climate. It is widely expected that China is likely to overtake the US in energy consumption and greenhouse gas (GHG) emissions during the first half of the 21st century. Therefore, there is considerable interest in the international community in searching for options that may help China slow down its growth in energy consumption and GHG emissions through improving energy efficiency and adopting more environmentally friendly fuel supplies such as renewable energy. This study examines the energy saving potential of three major residential energy end uses: household refrigeration, air-conditioning, and water heating. China is already the largest consumer market in the world for household appliances, and increasingly the global production base for consumer appliances. Sales of household refrigerators, …
Date: July 10, 2006
Creator: Lin, Jiang
Object Type: Report
System: The UNT Digital Library
An Automated Method to Quantify Radiation Damage in Human Blood Cells (open access)

An Automated Method to Quantify Radiation Damage in Human Blood Cells

Cytogenetic analysis of blood lymphocytes is a well established method to assess the absorbed dose in persons exposed to ionizing radiation. Because mature lymphocytes circulate throughout the body, the dose to these cells is believed to represent the average whole body exposure. Cytogenetic methods measure the incidence of structural aberrations in chromosomes as a means to quantify DNA damage which occurs when ionizing radiation interacts with human tissue. Methods to quantify DNA damage at the chromosomal level vary in complexity and tend to be laborious and time consuming. In a mass casualty scenario involving radiological/nuclear materials, the ability to rapidly triage individuals according to radiation dose is critically important. For high-throughput screening for dicentric chromosomes, many of the data collection steps can be optimized with motorized microscopes coupled to automated slide scanning platforms.
Date: July 10, 2006
Creator: Gordon K. Livingston, Mark S. Jenkins and Akio A. Awa
Object Type: Article
System: The UNT Digital Library
Ground Truth, Magnitude Calibration and Regional Phase Propagation and Detection in the Middle East and Horn of Africa (open access)

Ground Truth, Magnitude Calibration and Regional Phase Propagation and Detection in the Middle East and Horn of Africa

In this project, we are exploiting unique and open source seismic data sets to improve seismic monitoring across the Middle East (including the Iranian Plateau, Zagros Mountains, Arabian Peninsula, Turkish Plateau, Gulf of Aqaba, Dead Sea Rift) and the Horn of Africa (including the northern part of the East African Rift, Afar Depression, southern Red Sea and Gulf of Aden). The data sets are being used to perform three related tasks. (1) We are determining moment tensors, moment magnitudes and source depths for regional events in the magnitude 3.0 to 6.0 range. (2) These events are being used to characterize high-frequency (0.5-16 Hz) regional phase attenuation and detection thresholds, especially from events in Iran recorded at stations across the Arabian Peninsula. (3) We are collecting location ground truth at GT5 (local) and GT20 (regional) levels for seismic events with M > 2.5, including source geometry information and source depths. In the first phase of this project, seismograms from earthquakes in the Zagros Mountains recorded at regional distances have been inverted for moment tensors, and source depths for the earthquakes have been determined via waveform matching. Early studies of the distribution of seismicity in the Zagros region found evidence for earthquakes …
Date: July 10, 2006
Creator: Nyblade, A.; Adams, A.; Brazier, R.; Park, Y. & Rodgers, A.
Object Type: Article
System: The UNT Digital Library
Data Analysis for Infiltration Modeling: Techical Evaluation of Previous Soil Depth Estimation Methods and Develoment of Aternate Parameter Values (open access)

Data Analysis for Infiltration Modeling: Techical Evaluation of Previous Soil Depth Estimation Methods and Develoment of Aternate Parameter Values

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Date: July 10, 2006
Creator: Rehfeldt, K.
Object Type: Report
System: The UNT Digital Library
Non-molecular Phases of H2O and HF Under Detonation-like Conditions (open access)

Non-molecular Phases of H2O and HF Under Detonation-like Conditions

Energetic materials are known to produce simple molecular species, such as HF and H{sub 2}O, during detonation. The behavior of such species under conditions of simultaneous high pressure and temperature are unknown. The predicted high pressure superionic phases of water and HF are investigated via ab initio molecular dynamics. We study water at densities of 2.0-3.0 g/cc (34 -115 GPa) along the 2000 K isotherm. We find that extremely rapid (superionic) diffusion of protons occurs in a fluid phase at pressures between 34 and 58 GPa. A transition to a stable body-centered cubic (bcc) O lattice with superionic proton conductivity is observed between 70 and 75 GPa. We find that all molecular species at pressures greater than 75 GPa are too short lived to be classified as bound states. Up to 95 GPa, we find a solid superionic phase characterized by covalent O-H bonding. Above 95 GPa, a transient network phase is found characterized by symmetric O-OH hydrogen bonding with nearly 50% covalent character. Ab initio molecular dynamics H simulations of HF were conducted at densities of 1.8-4.0 g/cc along the 900 K isotherm. According to our simulations, a unique form of (symmetric) hydrogen bonding could play a significant role …
Date: July 10, 2006
Creator: Fried, L E; Goldman, N; Kuo, I W & Mundy, C J
Object Type: Article
System: The UNT Digital Library
Two-Photon Exchange Model for Production of Neutral Meson Pairs in e+ e- Annihilation (open access)

Two-Photon Exchange Model for Production of Neutral Meson Pairs in e+ e- Annihilation

A vector-dominance two-photon exchange model is proposed to explain the recently observed production of {rho}{sup 0}{rho}{sup 0} and {rho}{sup 0}{phi} pairs in e{sup +}e{sup -} annihilation at 10.58 GeV with the BaBar detector. All the observed features of the data--angular and decay distributions, rates--are in agreement with the model. Predictions are made for yet-unobserved final states.
Date: July 10, 2006
Creator: Davier, M.; Peskin, M. & Snyder, A.
Object Type: Report
System: The UNT Digital Library
Final Report - Advanced Conceptual Models for Unsaturated and Two-Phase Flow in Fractured Rock (open access)

Final Report - Advanced Conceptual Models for Unsaturated and Two-Phase Flow in Fractured Rock

The Department of Energy Environmental Management Program is faced with two major issues involving two-phase flow in fractured rock; specifically, transport of dissolved contaminants in the Vadose Zone, and the fate of Dense Nonaqueous Phase Liquids (DNAPLs) below the water table. Conceptual models currently used to address these problems do not correctly include the influence of the fractures, thus leading to erroneous predictions. Recent work has shown that it is crucial to understand the topology, or ''structure'' of the fluid phases (air/water or water/DNAPL) within the subsurface. It has also been shown that even under steady boundary conditions, the influence of fractures can lead to complex and dynamic phase structure that controls system behavior, with or without the presence of a porous rock matrix. Complicated phase structures within the fracture network can facilitate rapid transport, and lead to a sparsely populated and widespread distribution of concentrated contaminants; these qualities are highly difficult to describe with current conceptual models. The focus of our work is to improve predictive modeling through the development of advanced conceptual models for two-phase flow in fractured rock.
Date: July 10, 2006
Creator: Nicholl, Michael J.
Object Type: Report
System: The UNT Digital Library
X-Ray Spectral Study of the Photoionized Stellar Wind in Vela X-1 (open access)

X-Ray Spectral Study of the Photoionized Stellar Wind in Vela X-1

We present results from quantitative modeling and spectral analysis of the high mass X-ray binary system Vela X-1 obtained with the Chandra High Energy Transmission Grating Spectrometer. The observations cover three orbital phase ranges within a single binary orbit. The spectra exhibit emission lines from H-like and He-like ions driven by photoionization, as well as fluorescent emission lines from several elements in lower charge states. The properties of these X-ray lines are measured with the highest accuracy to date. In order to interpret and make full use of the high-quality data, we have developed a simulator, which calculates the ionization and thermal structure of a stellar wind photoionized by an X-ray source, and performs Monte Carlo simulations of X-ray photons propagating through the wind. The emergent spectra are then computed as a function of the viewing angle accurately accounting for photon transport in three dimensions including dynamics. From comparisons of the observed spectra with results from the simulator, we are able to find the ionization structure and the geometrical distribution of material in the stellar wind of Vela X-1 that can reproduce the observed spectral line intensities and continuum shapes at different orbital phases remarkably well. We find that the …
Date: July 10, 2006
Creator: Watanabe, Shin; Sako, Masao; Ishida, Manabu; Ishisaki, Yoshitaka; Kahn, Steven M.; Kohmura, Takayoshi et al.
Object Type: Article
System: The UNT Digital Library
Physiomics Array: A Platform for Genome Research and Cultivation of Difficult-to-Cultivate Microorganisms Final Technical Report (open access)

Physiomics Array: A Platform for Genome Research and Cultivation of Difficult-to-Cultivate Microorganisms Final Technical Report

A scalable array technology for parametric control of high-throughput cell cultivations is demonstrated. The technology makes use of commercial printed circuit board (PCB) technology, integrated circuit sensors, and an electrochemical gas generation system. We present results for an array of eight 250 μl microbioreactors. Each bioreactor contains an independently addressable suite that provides closed-loop temperature control, generates feed gas electrochemically, and continuously monitors optical density. The PCB technology allows for the assembly of additional off-the-shelf components into the microbioreactor array; we demonstrate the use of a commercial ISFET chip to continuously monitor culture pH. The electrochemical dosing system provides a powerful paradigm for reproducible gas delivery to high-density arrays of microreactors. We have scaled the technology to a standard 96-well format and have constructed a system that could be easily assembled.
Date: July 10, 2006
Creator: Keasling, Jay D.
Object Type: Report
System: The UNT Digital Library
Fine-scale Horizontal Structure of Arctic Mixed-Phase Clouds. (open access)

Fine-scale Horizontal Structure of Arctic Mixed-Phase Clouds.

Recent in situ observations in stratiform clouds suggest that mixed phase regimes, here defined as limited cloud volumes containing both liquid and solid water, are constrained to narrow layers (order 100 m) separating all-liquid and fully glaciated volumes (Hallett and Viddaurre, 2005). The Department of Energy Atmospheric Radiation Measurement Program's (DOE-ARM, Ackerman and Stokes, 2003) North Slope of Alaska (NSA) ARM Climate Research Facility (ACRF) recently started collecting routine measurement of radar Doppler velocity power spectra from the Millimeter Cloud Radar (MMCR). Shupe et al. (2004) showed that Doppler spectra has potential to separate the contributions to the total reflectivity of the liquid and solid water in the radar volume, and thus to investigate further Hallett and Viddaurre's findings. The Mixed-Phase Arctic Cloud Experiment (MPACE) was conducted along the NSA to investigate the properties of Arctic mixed phase clouds (Verlinde et al., 2006). We present surface based remote sensing data from MPACE to discuss the fine-scale structure of the mixed-phase clouds observed during this experiment.
Date: July 10, 2006
Creator: Rambukkange,M.; Verlinde, J.; Elorante, E.; Luke, E.; Kollias, P. & Shupe, M.
Object Type: Article
System: The UNT Digital Library
Probing Dark Energy via Neutrino and Supernova Observatories (open access)

Probing Dark Energy via Neutrino and Supernova Observatories

A novel method for extracting cosmological evolution parameters is proposed, using a probe other than light: future observations of the diffuse anti-neutrino flux emitted from core-collapse supernovae (SNe), combined with the SN rate extracted from future SN surveys. The relic SN neutrino differential flux can be extracted by using future neutrino detectors such as Gadolinium-enriched, megaton, water detectors or 100-kiloton detectors of liquid Argon or liquid scintillator. The core-collapse SN rate can be reconstructed from direct observation of SN explosions using future precision observatories. Our method, by itself, cannot compete with the accuracy of the optical-based measurements but may serve as an important consistency check as well as a source of complementary information. The proposal does not require construction of a dedicated experiment, but rather relies on future experiments proposed for other purposes.
Date: July 10, 2006
Creator: Hall, Lawrence; Hall, Lawrence J.; Murayama, Hitoshi; Papucci, Michele & Perez, Gilad
Object Type: Report
System: The UNT Digital Library
Brilliant Sm, Eu, Tb and Dy chiral lanthanide complexes withstrong circularly polarized luminescence (open access)

Brilliant Sm, Eu, Tb and Dy chiral lanthanide complexes withstrong circularly polarized luminescence

The synthesis, characterization and luminescent behavior of trivalent Sm, Eu, Dy and Tb complexes of two enantiomeric, octadentate, chiral, 2-hydroxyisophthalamide ligands are reported. These complexes are highly luminescent in solution. Functionalization of the achiral parent ligand with a chiral 1-phenylethylamine substituent on the open face of the complex in close proximity to the metal center yields complexes with strong circularly polarized luminescence (CPL) activity. This appears to be the first example of a system utilizing the same ligand architecture to sensitize four different lanthanide cations and display CPL activity. The luminescence dissymmetry factor, g{sub lum}, recorded for the Eu(III) complex is one of the highest values reported, and this is the first time the CPL effect has been demonstrated for a Sm(III) complex with a chiral ligand. The combination of high luminescence intensity with CPL activity should enable new bioanalytical applications of macromolecules in chiral environments.
Date: July 10, 2006
Creator: Petoud, Stephane; Muller, Gilles; Moore, Evan G.; Xu, Jide; Sokolnicki, Jurek; Riehl, James P. et al.
Object Type: Article
System: The UNT Digital Library