The Energy Diameter Effect (open access)

The Energy Diameter Effect

Various relations for the detonation energy and velocity as they relate to the inverse radius of the cylinder are explored. The detonation rate-inverse slope relation seen in reactive flow models can be used to derive the familiar Eyring equation. Generalized inverse radii can be shown to fit large quantities of cylinder and sphere results. A rough relation between detonation energy and detonation velocity is found from collected JWL values. Cylinder test data for ammonium nitrate mixes down to 6.35 mm radii are presented, and a size energy effect is shown to exist in the Cylinder test data. The relation that detonation energy is roughly proportional to the square of the detonation velocity is shown by data and calculation.
Date: April 20, 2007
Creator: Souers, P; Vitello, P; Garza, R & Hernandez, A
Object Type: Article
System: The UNT Digital Library
Climate Modeling using High-Performance Computing (open access)

Climate Modeling using High-Performance Computing

The Center for Applied Scientific Computing (CASC) and the LLNL Climate and Carbon Science Group of Energy and Environment (E&E) are working together to improve predictions of future climate by applying the best available computational methods and computer resources to this problem. Over the last decade, researchers at the Lawrence Livermore National Laboratory (LLNL) have developed a number of climate models that provide state-of-the-art simulations on a wide variety of massively parallel computers. We are now developing and applying a second generation of high-performance climate models.
Date: April 20, 2006
Creator: Mirin, A. A. & Wickett, M.
Object Type: Report
System: The UNT Digital Library
Geothermal Direct Use Feasibility Study on the Fort Bidwell Indian Reservation (open access)

Geothermal Direct Use Feasibility Study on the Fort Bidwell Indian Reservation

The Fort Bidwell Indian Reservation (FBIR) is rich in renewable energy resources. Development of its geothermal resources has the potential to profoundly affect the energy and economic future of the FBIC. Geothermal energy can contribute to making the reservation energy self-sufficient and, potentially, an energy exporter. The feasibility study assessed the feasibility of installing a geothermal district heating system to provide low-cost, efficient heating of existing and planned residences, community buildings and water, using an existing geothermal well, FB-3.
Date: April 20, 2007
Creator: Merrick, Dale
Object Type: Report
System: The UNT Digital Library
Structures in Molecular Clouds: Modeling (open access)

Structures in Molecular Clouds: Modeling

We attempt to predict the observed morphology, column density and velocity gradient of Pillar II of the Eagle Nebula, using Rayleigh Taylor (RT) models in which growth is seeded by an initial perturbation in density or in shape of the illuminated surface, and cometary models in which structure is arises from a initially spherical cloud with a dense core. Attempting to mitigate suppression of RT growth by recombination, we use a large cylindrical model volume containing the illuminating source and the self-consistently evolving ablated outflow and the photon flux field, and use initial clouds with finite lateral extent. An RT model shows no growth, while a cometary model appears to be more successful at reproducing observations.
Date: April 20, 2006
Creator: Kane, J. O.; Mizuta, A.; Pound, M. W.; Remington, B. A. & Ryutov, D. D.
Object Type: Article
System: The UNT Digital Library
Feasibility of using biological degradation for the on-sitet reatment of mixed wastes (open access)

Feasibility of using biological degradation for the on-sitet reatment of mixed wastes

This research was conducted to investigate the feasibility of applying microbial biodegradation as a treatment technology for wastes containing radioactive elements and organic solvents (mixed wastes). In this study, we focused our efforts on the treatment of wastes generated by biomedical research as the result of purifying tritium labeled compounds by high-performance liquid chromatography (HPLC). These wastes are typically 80 percent water with 20 percent acetonitrile or methanol or a mixture of both. The objective was to determine the potential of using biodegradation to treat the solvent component of tritiated mixed waste to a concentration below the land disposal restriction standard (1mg/L for acetonitrile). Once the standard is reached, the remaining radioactive waste is no longer classified as a mixed waste and it can then be solidified and placed in a secure landfill. This investigation focused on treating a 10 percent acetonitrile solution, which was used as a non-radioactive surrogate for HPLC waste, in a bioreactor. The results indicated that the biodegradation process could treat this solution down to less than 1 mg/L to meet the land disposal restriction standard.
Date: April 20, 2004
Creator: Stringfellow, William T.; Komada, Tatsuyuki & Chang, Li-Yang
Object Type: Article
System: The UNT Digital Library
Transportation Routing Analysis Georgraphic Information System (WebTRAGIS) User's Manual (open access)

Transportation Routing Analysis Georgraphic Information System (WebTRAGIS) User's Manual

In the early 1980s, Oak Ridge National Laboratory (ORNL) developed two transportation routing models: HIGHWAY, which predicts truck transportation routes, and INTERLINE, which predicts rail transportation routes. Both of these models have been used by the U.S. Department of Energy (DOE) community for a variety of routing needs over the years. One of the primary uses of the models has been to determine population-density information, which is used as input for risk assessment with the RADTRAN model, which is available on the TRANSNET computer system. During the recent years, advances in the development of geographic information systems (GISs) have resulted in increased demands from the user community for a GIS version of the ORNL routing models. In April 1994, the DOE Transportation Management Division (EM-261) held a Baseline Requirements Assessment Session with transportation routing experts and users of the HIGHWAY and INTERLINE models. As a result of the session, the development of a new GIS routing model, Transportation Routing Analysis GIS (TRAGIS), was initiated. TRAGIS is a user-friendly, GIS-based transportation and analysis computer model. The older HIGHWAY and INTERLINE models are useful to calculate routes, but they cannot display a graphic of the calculated route. Consequently, many users have experienced …
Date: April 20, 2000
Creator: Michelhaugh, R. D.
Object Type: Report
System: The UNT Digital Library
Spin Spectrometer at the ALS and APS (open access)

Spin Spectrometer at the ALS and APS

A spin-resolving photoelectron spectrometer, the"Spin Spectrometer," has been designed and built. It has been utilized at both the Advanced Light Source in Berkeley, CA, and the Advanced Photon Source in Argonne, IL. Technical details and an example of experimental results are presented here.
Date: April 20, 2007
Creator: Laboratory, Lawrence Livermore National; Missouri-Rolla, University of; Technologies, Boyd; Morton, Simon A; Morton, Simon A; Tobin, James G et al.
Object Type: Article
System: The UNT Digital Library
Speech recognition systems on the Cell Broadband Engine (open access)

Speech recognition systems on the Cell Broadband Engine

In this paper we describe our design, implementation, and first results of a prototype connected-phoneme-based speech recognition system on the Cell Broadband Engine{trademark} (Cell/B.E.). Automatic speech recognition decodes speech samples into plain text (other representations are possible) and must process samples at real-time rates. Fortunately, the computational tasks involved in this pipeline are highly data-parallel and can receive significant hardware acceleration from vector-streaming architectures such as the Cell/B.E. Identifying and exploiting these parallelism opportunities is challenging, but also critical to improving system performance. We observed, from our initial performance timings, that a single Cell/B.E. processor can recognize speech from thousands of simultaneous voice channels in real time--a channel density that is orders-of-magnitude greater than the capacity of existing software speech recognizers based on CPUs (central processing units). This result emphasizes the potential for Cell/B.E.-based speech recognition and will likely lead to the future development of production speech systems using Cell/B.E. clusters.
Date: April 20, 2007
Creator: Liu, Y.; Jones, H.; Vaidya, S.; Perrone, M.; Tydlitat, B. & Nanda, A.
Object Type: Article
System: The UNT Digital Library
Formation of Pillars at the Boundaries between HII Regions and Molecular Clouds (open access)

Formation of Pillars at the Boundaries between HII Regions and Molecular Clouds

We investigate numerically the hydrodynamic instability of an ionization front (IF) accelerating into a molecular cloud, with imposed initial perturbations of different amplitudes. When the initial amplitude is small, the imposed perturbation is completely stabilized and does not grow. When the initial perturbation amplitude is large enough, roughly the ratio of the initial amplitude to wavelength is greater than 0.02, portions of the IF temporarily separate from the molecular cloud surface, locally decreasing the ablation pressure. This causes the appearance of a large, warm HI region and triggers nonlinear dynamics of the IF. The local difference of the ablation pressure and acceleration enhances the appearance and growth of a multimode perturbation. The stabilization usually seen at the IF in the linear regimes does not work due to the mismatch of the modes of the perturbations at the cloud surface and in density in HII region above the cloud surface. Molecular pillars are observed in the late stages of the large amplitude perturbation case. The velocity gradient in the pillars is in reasonably good agreement with that observed in the Eagle Nebula. The initial perturbation is imposed in three different ways: in density, in incident photon number flux, and in the …
Date: April 20, 2006
Creator: Mizuta, A.; Kane, J. O.; Pound, M. W.; Remington, B. A.; Ryutov, D. D. & Takabe, H.
Object Type: Article
System: The UNT Digital Library
Numerical Simulation of a Laboratory-Scale Turbulent SlotFlame (open access)

Numerical Simulation of a Laboratory-Scale Turbulent SlotFlame

We present three-dimensional, time-dependent simulations ofthe flowfield of a laboratory-scale slot burner. The simulations areperformed using an adaptive time-dependent low Mach number combustionalgorithm based on a second-order projection formulation that conservesboth species mass and total enthalpy. The methodology incorporatesdetailed chemical kinetics and a mixture model for differential speciesdiffusion. Methane chemistry and transport are modeled using the DRM-19mechanism along with its associated thermodynamics and transportdatabases. Adaptive mesh refinementdynamically resolves the flame andturbulent structures. Detailedcomparisons with experimental measurementsshow that the computational results provide a good prediction of theflame height, the shape of the time-averaged parabolic flame surfacearea, and the global consumption speed (the volume per second ofreactants consumed divided by the area of the time-averaged flame). Thethickness of the computed flamebrush increases in the streamwisedirection, and the flamesurface density profiles display the same generalshapes as the experiment. The structure of the simulated flame alsomatches the experiment; reaction layers are thin (typically thinner than1 mm) and the wavelengths of large wrinkles are 5--10 mm. Wrinklesamplify to become long fingers of reactants which burn through at a neckregion, forming isolated pockets of reactants. Thus both the simulatedflame and the experiment are in the "corrugated flameletregime."
Date: April 20, 2006
Creator: Bell, John B.; Day, Marcus S.; Grcar, Joseph F.; Lijewski,Michael J.; Driscoll, James F. & Filatyev, Sergei A.
Object Type: Article
System: The UNT Digital Library
Benchmark Measurements of the Ionization Balance of Non-LTE Gold (open access)

Benchmark Measurements of the Ionization Balance of Non-LTE Gold

The authors present a series of benchmark measurements of the ionization balance of well characterized gold plasmas with and without external radiation fields at electron densities near 10{sup 21} cm{sup -3} and various electron temperatures spanning the range 0.8 to 2.4 keV. They have analyzed time- and space-resolved M-shell gold emission spectra using a sophisticated collisional-radiative model with hybrid level structure, finding average ion changes <Z> ranging from 42 to 50. At the lower temperatures, the spectra exhibit significant sensitivity to external radiation fields and include emission features from complex N-shell ions not previously studied at these densities. The measured spectra and inferred <Z> provide a stringent test for non-local thermodynamic equilibrium (non-LTE) models of complex high-Z ions.
Date: April 20, 2007
Creator: Heeter, R. F.; Hansen, S. B.; Fournier, K. B.; Foord, M. E.; Froula, D. H.; Mackinnon, A. J. et al.
Object Type: Article
System: The UNT Digital Library
Potential Alternative Energy Technologies on the Outer Continental Shelf. (open access)

Potential Alternative Energy Technologies on the Outer Continental Shelf.

This technical memorandum (TM) describes the technology requirements for three alternative energy technologies for which pilot and/or commercial projects on the U.S. Outer Continental Shelf (OCS) are likely to be proposed within the next five to seven years. For each of the alternative technologies--wind, wave, and ocean current--the TM first presents an overview. After each technology-specific overview, it describes the technology requirements for four development phases: site monitoring and testing, construction, operation, and decommissioning. For each phase, the report covers the following topics (where data are available): facility description, electricity generated, ocean area (surface and bottom) occupied, resource requirements, emissions and noise sources, hazardous materials stored or used, transportation requirements, and accident potential. Where appropriate, the TM distinguishes between pilot-scale (or demonstration-scale) facilities and commercial-scale facilities.
Date: April 20, 2007
Creator: Elcock, D. & Assessment, Environmental
Object Type: Report
System: The UNT Digital Library
Molecular beam epitaxy of InN dots on nitrided sapphire (open access)

Molecular beam epitaxy of InN dots on nitrided sapphire

A series of self-assembled InN dots are grown by radio frequency (RF) plasma-assisted molecular beam epitaxy (MBE) directly on nitrided sapphire. Initial nitridation of the sapphire substrates at 900 C results in the formation of a rough AlN surface layer, which acts as a very thin buffer layer and facilitates the nucleation of the InN dots according to the Stranski-Krastanow growth mode, with a wetting layer of {approx}0.9 nm. Atomic force microscopy (AFM) reveals that well-confined InN nanoislands with the greatest height/width at half-height ratio of 0.64 can be grown at 460 C. Lower substrate temperatures result in a reduced aspect ratio due to a lower diffusion rate of the In adatoms, whereas the thermal decomposition of InN truncates the growth at T>500 C. The densities of separated dots vary between 1.0 x 10{sup 10} cm{sup -2} and 2.5 x 10{sup 10} cm{sup -2} depending on the growth time. Optical response of the InN dots under laser excitation is studied with apertureless near-field scanning optical microscopy and photoluminescence spectroscopy, although no photoluminescence is observed from these samples. In view of the desirable implementation of InN nanostructures into photonic devices, the results indicate that nitrided sapphire is a suitable substrate for …
Date: April 20, 2007
Creator: Romanyuk, Yaroslav E.; Dengel, Radu-Gabriel; Stebounova, LarissaV. & Leone, Stephen R.
Object Type: Article
System: The UNT Digital Library
Is the beta phase maximal? (open access)

Is the beta phase maximal?

indicates that 2|Vub / Vcb/ Vus| = (1-z) with z given by z = 0.19 +(-) 0.14. This fact implies that irrespective of the form of the quark Yukawa matrices, the measured value of the SM CP phase beta is approximately the maximum allowed by the measured absolute values of the CKM elements. This is beta = pi/6 - z/sqrt{3} for gamma = pi/3 + z/sqrt{3}, which implies alpha = pi/2. Alternatively, assuming that beta is exactly maximal and using the experimental measurement, sin(2beta) = 0.726+(-) 0.037, the phase gamma is predicted to be gamma = pi/2 - beta = 66.3 +(-) 1.7. The maximality of beta, if confirmed by the near-future experiments, may give us some clues as to the origin of CP violation.
Date: April 20, 2005
Creator: Ferrandis, Javier & Ferrandis, Javier
Object Type: Article
System: The UNT Digital Library
A screening model for evaluating the degradation and transport of MTBE and other fuel oxygenates in the subsurface (open access)

A screening model for evaluating the degradation and transport of MTBE and other fuel oxygenates in the subsurface

Methyl tert-butyl ether (MTBE) has received high attention as it contributed to cleaner air and contaminated thousands of underground storage tank sites. Because MTBE is very water soluble, it is more difficult to remove from water by conventional remediation techniques. Therefore, biodegradation of MTBE has become a remediation alternative. In order to understand the transport and transformation processes, they present a closed form solution as a screening tool in this paper. The possible reaction pathways of first-order reactions are described as a reaction matrix. The singular value decomposition is conducted analytically to decouple the partial differential equations of the multi-species transport system coupled by the reaction matrix into multiple independent subsystems. Therefore, the complexity of mathematical description for the reactive transport system is significantly reduced and analytical solutions may be previously available or easily derived.
Date: April 20, 2004
Creator: Sun, Y. & Lu, X.
Object Type: Article
System: The UNT Digital Library
Hyperdispersion Grating Arrangements for Compact Pulse Compressors and Expanders (open access)

Hyperdispersion Grating Arrangements for Compact Pulse Compressors and Expanders

A novel, but general, arrangement of parallel sets of gratings is presented that can effectively increase the dispersion of pulse compressors and expanders by over an order of magnitude. These arrangements will dramatically reduce the footprint of the pulse compressors and expanders used in CPA.
Date: April 20, 2004
Creator: Fittinghoff, D N; Molander, W A & Barty, C J
Object Type: Article
System: The UNT Digital Library
Implementation Plans for a Systems Microbiology and Extremophile Research Facility (open access)

Implementation Plans for a Systems Microbiology and Extremophile Research Facility

Introduction Biological organisms long ago solved many problems for which scientists and engineers seek solutions. Microbes in particular offer an astonishingly diverse set of capabilities that can help revolutionize our approach to solving many important DOE problems. For example, photosynthetic organisms can generate hydrogen from light while simultaneously sequestering carbon. Others can produce enzymes that break down cellulose and other biomass to produce liquid fuels. Microbes in water and soil can capture carbon and store it in the earth and ocean depths. Understanding the dynamic interaction between living organisms and the environment is critical to predicting and mitigating the impacts of energy-production-related activities on the environment and human health. Collectively, microorganisms contain most of the biochemical diversity on Earth and they comprise nearly one-half of its biomass. They primary impact the planet by acting as catalysts of biogeochemical cycles; they capture light energy and fix CO2 in the worlds oceans, they degrade plant polymers and convert them to humus in soils, they weather rocks and facilitate mineral precipitation. Although the ability of selected microorganisms to participate in these processes is known, they rarely live in monoculture but rather function within communities. In spite of this, little is known about the …
Date: April 20, 2009
Creator: Wiley, H. S.
Object Type: Report
System: The UNT Digital Library
Improving the Performance of Lithium Ion Batteries at Low Temperature (open access)

Improving the Performance of Lithium Ion Batteries at Low Temperature

The ability for Li-ion batteries to operate at low temperatures is extremely critical for the development of energy storage for electric and hybrid electric vehicle technologies. Currently, Li-ion cells have limited success in operating at temperature below –10 deg C. Electrolyte conductivity at low temperature is not the main cause of the poor performance of Li-ion cells. Rather the formation of a tight interfacial film between the electrolyte and the electrodes has often been an issue that resulted in a progressive capacity fading and limited discharge rate capability. The objective of our Phase I work is to develop novel electrolytes that can form low interfacial resistance solid electrolyte interface (SEI) films on carbon anodes and metal oxide cathodes. From the results of our Phase I work, we found that the interfacial impedance of Fluoro Ethylene Carbonate (FEC) electrolyte at the low temperature of –20degC is astonishingly low, compared to the baseline 1.2M LiPFEMC:EC:PC:DMC (10:20:10:60) electrolyte. We found that electrolyte formulations with fluorinated carbonate co-solvent have excellent film forming properties and better de-solvation characteristics to decrease the interfacial SEI film resistance and facilitate the Li-ion diffusion across the SEI film. The very overwhelming low interfacial impedance for FEC electrolytes will translate …
Date: April 20, 2007
Creator: Nguyen, Trung H.; Marren, Peter & Gering, Kevin
Object Type: Report
System: The UNT Digital Library
300 Area D4 Project 1st Quarter Fiscal Year 2006 Building Completion Report (open access)

300 Area D4 Project 1st Quarter Fiscal Year 2006 Building Completion Report

This report documents the deactivation, decontamination, decommissioning, and demolition of the MO-052, 3225, 334, 334A, and 334-TF Buildings in the 300 Area of the Hanford Site. The D4 of these facilities included characterization, engineering, removal of hazardous and radiologically contaminated materials, equipment removal, utility disconnection, deactivation, decontamination, demolition of the structure, and stabilization or removal of the remaining slab and foundation as appropriate.
Date: April 20, 2006
Creator: Smith, David S.
Object Type: Report
System: The UNT Digital Library
Statistical Analysis and Geologic Evaluation of Laboratory-Derived Physical Property Data for Selected Nevada Test Site Core Samples of Non-Zeolitized Tuffs (open access)

Statistical Analysis and Geologic Evaluation of Laboratory-Derived Physical Property Data for Selected Nevada Test Site Core Samples of Non-Zeolitized Tuffs

A statistical analysis and geologic evaluation of recently acquired laboratory-derived physical property data are being performed to better understand and more precisely correlate physical properties with specific geologic parameters associated with non-zeolitized tuffs at the Nevada Test Site. Physical property data include wet and dry bulk density, grain density (i.e., specific gravity), total porosity, and effective porosity. Geologic parameters utilized include degree of welding, lithology, stratigraphy, geographic area, and matrix mineralogy (i.e., vitric versus devitrified). Initial results indicate a very good correlation between physical properties and geologic parameters such as degree of welding, lithology, and matrix mineralogy. However, physical properties appear to be independent of stratigraphy and geographic area, suggesting that the data are transferrable with regards to these two geologic parameters. Statistical analyses also indicate that the assumed grain density of 2.65 grams per cubic centimeter used to calculate porosity in some samples is too high. This results in corresponding calculated porosity values approximately 5 percent too high (e.g., 45 percent versus 40 percent), which can be significant in the lower porosity rocks. Similar analyses and evaluations of zeolitic tuffs and carbonate rock physical properties data are ongoing as well as comparisons to geophysical log values.
Date: April 20, 2009
Creator: National Security Technologies, LLC
Object Type: Article
System: The UNT Digital Library
Task 1 Final Report, Theoretical/Mathematical Modeling of Ultrasonic Wave Propagation in Anisotropic Polycrystalline Stainless Steels (open access)

Task 1 Final Report, Theoretical/Mathematical Modeling of Ultrasonic Wave Propagation in Anisotropic Polycrystalline Stainless Steels

One of the tasks of the U.S. Nuclear Regulatory Commission-sponsored project titled "Reliability of Nondestructive Examination (NDE) for Nuclear Power Plant (NPP) Inservice Examination (ISI)" is to provide collaborative assistance to Commissariat à l’Energie Atomique (CEA) in France through theoretical predictions of ultrasonic scattering by grains of cast stainless steels (CASS) components. More specifically, a mathematical treatment of ultrasonic scattering in media having duplex micro¬structure is sought because cast stainless steel components often contains larger-scale macrograins that are composed of sub-grains/colonies. In this report, we present formal mathematical theories for ultrasonic wave propagation in polycrystalline aggregates having both simple (composed of grains only) and complex microstructures (having macrograins and sub-grains/colonies). Computations based on these theories are then carried out for ultrasonic backscatter power, attenuation due to scattering, and phase velocity dispersions. Specifically, numerical results are presented for backscatter coefficient for plane longitudinal wave propagating in duplex steel containing macrograins and colonies. Furthermore, the expected propagation characteristics (attenuation coefficient and phase velocity) are computed and described in this report for plane longitudinal waves propagating in (1) steels composed of randomly oriented grains, (2) [001] aligned grains encountered in austenitic stainless steel welds and casts, and (3) duplex steels.
Date: April 20, 2009
Creator: Ahmed, Salahuddin & Anderson, Michael T.
Object Type: Report
System: The UNT Digital Library
Stepwise DNA Methylation Changes Are Linked to Escape from Defined Proliferation Barriers and Mammary Epithelial Cell Immortalization (open access)

Stepwise DNA Methylation Changes Are Linked to Escape from Defined Proliferation Barriers and Mammary Epithelial Cell Immortalization

The timing and progression of DNA methylation changes during carcinogenesis are not completely understood. To develop a timeline of aberrant DNA methylation events during malignant transformation, we analyzed genome-wide DNA methylation patterns in an isogenic human mammary epithelial cell (HMEC) culture model of transformation. To acquire immortality and malignancy, the cultured finite lifespan HMEC must overcome two distinct proliferation barriers. The first barrier, stasis, is mediated by the retinoblastoma protein and can be overcome by loss of p16(INK4A) expression. HMEC that escape stasis and continue to proliferate become genomically unstable before encountering a second more stringent proliferation barrier, telomere dysfunction due to telomere attrition. Rare cells that acquire telomerase expression may escape this barrier, become immortal, and develop further malignant properties. Our analysis of HMEC transitioning from finite lifespan to malignantly transformed showed that aberrant DNA methylation changes occur in a stepwise fashion early in the transformation process. The first aberrant DNA methylation step coincides with overcoming stasis, and results in few to hundreds of changes, depending on how stasis was overcome. A second step coincides with immortalization and results in hundreds of additional DNA methylation changes regardless of the immortalization pathway. A majority of these DNA methylation changes are …
Date: April 20, 2009
Creator: Novak, Petr; Jensen, Taylor J.; Garbe, James C.; Stampfer, Martha R. & Futscher, Bernard W.
Object Type: Article
System: The UNT Digital Library
UGTA Photograph Database (open access)

UGTA Photograph Database

One of the advantages of the Nevada Test Site (NTS) is that most of the geologic and hydrologic features such as hydrogeologic units (HGUs), hydrostratigraphic units (HSUs), and faults, which are important aspects of flow and transport modeling, are exposed at the surface somewhere in the vicinity of the NTS and thus are available for direct observation. However, due to access restrictions and the remote locations of many of the features, most Underground Test Area (UGTA) participants cannot observe these features directly in the field. Fortunately, National Security Technologies, LLC, geologists and their predecessors have photographed many of these features through the years. During fiscal year 2009, work was done to develop an online photograph database for use by the UGTA community. Photographs were organized, compiled, and imported into Adobe® Photoshop® Elements 7. The photographs were then assigned keyword tags such as alteration type, HGU, HSU, location, rock feature, rock type, and stratigraphic unit. Some fully tagged photographs were then selected and uploaded to the UGTA website. This online photograph database provides easy access for all UGTA participants and can help “ground truth” their analytical and modeling tasks. It also provides new participants a resource to more quickly learn the …
Date: April 20, 2009
Creator: National Security Technologies, LLC
Object Type: Article
System: The UNT Digital Library
Grid-based methods for diatomic quantum scattering problems II: Time-dependent treatment of single- and two-photon ionization of H2+ (open access)

Grid-based methods for diatomic quantum scattering problems II: Time-dependent treatment of single- and two-photon ionization of H2+

The time-dependent Schr\"odinger equation for H2+ in a time-varying electromagnetic field is solved in the fixed-nuclei approximation using a previously developed finite-element/ discrete variable representation in prolate spheroidal coordinates. Amplitudes for single- and two-photon ionization are obtained using the method of exterior complex scaling to effectively propagate the field-free solutions from the end of the radiation pulse to infinite times. Cross sections are presented for one-and two-photon ionization for both parallel and perpendicular polarization of the photon field, as well as photoelectron angular distributions for two-photon ionization.
Date: April 20, 2009
Creator: Rescigno, Thomas N.; Tao, L. & McCurdy, C.W.
Object Type: Article
System: The UNT Digital Library