Fermi Large Area Telescope Observations of the Cosmic-Ray Induced (open access)

Fermi Large Area Telescope Observations of the Cosmic-Ray Induced

We report on measurements of the cosmic-ray induced {gamma}-ray emission of Earth's atmosphere by the Large Area Telescope onboard the Fermi Gamma-ray Space Telescope. The LAT has observed the Earth during its commissioning phase and with a dedicated Earth-limb following observation in September 2008. These measurements yielded {approx} 6.4 x 10{sup 6} photons with energies > 100 MeV and {approx} 250 hours total livetime for the highest quality data selection. This allows the study of the spatial and spectral distributions of these photons with unprecedented detail. The spectrum of the emission - often referred to as Earth albedo gamma-ray emission - has a power-law shape up to 500 GeV with spectral index {Lambda} = 2.79 {+-} 0.06.
Date: February 29, 2012
Creator: Abdo, A. A.
Object Type: Report
System: The UNT Digital Library
Study of Charmed Baryon Sigma(C)(2800) Production at the BaBar Experiment (open access)

Study of Charmed Baryon Sigma(C)(2800) Production at the BaBar Experiment

This dissertation reports on a study of search for an orbitally excited state of charmed baryons {Sigma}{sub c}{sup 0}(2800) and {Sigma}{sub c}{sup ++}(2800). They measure the widths, momentum spectrum and production cross-section for these states decaying into a {Lambda}{sub c}{sup +} and a charged {pi}. The analysis uses 230 fb{sup -1} of data collected at BABAR detector operating at PEP-II collider at Stanford Linear Accelerator Center. The data is collected in the region of {Upsilon}(4S) an {approx} 40 MeV below the resonance. {Lambda}{sub c}{sup +} baryon is reconstructed in the decay mode pK{sup -}{pi}{sup +}. The {Sigma}{sub c}(2800) baryon production at continuum is observed to be quite significant for x{sub p} > 0.7, where x{sub p} = p/{radical}E{sup 2}+M{sup 2} is the scaled momentum and varies from 0.0 to 1.0. The momentum spectrum is measured by considering the corrected yield for momentum bins above x{sub p} > 0.5 and can be parameterized very well by a Peterson function, given by: dN/dx{sub p} {proportional_to} 1/x{sub p}(1 - 1/x{sub p} - {epsilon}/1-x{sub p}){sup 2}. The values for the peterson parameter {epsilon}, are found to be 0.050 {+-} 0.010 for {Sigma}{sub c}{sup 0}(2800) and 0.057 {+-} 0.012 for {Sigma}{sub c}{sup ++}(2800). They use …
Date: February 29, 2008
Creator: Ahmded, Shamona
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Extraction of pores from microtomographic reconstructions of intact soil aggregates (open access)

Extraction of pores from microtomographic reconstructions of intact soil aggregates

Segmentation of features is often a necessary step in the analysis of volumetric data. The authors have developed a simple technique for extracting voids from irregular volumetric data sets. In this work they look at extracting pores from soil aggregates. First, they identify a threshold that gives good separability of the object from the background. They then segment the object, and perform connected components analysis on the pores within the object. Using their technique pores that break the surface can be segmented along with pores completely contained in the initially segmented object.
Date: February 29, 2000
Creator: Albee, P. B.; Stockman, G. C. & Smucker, A. J. M.
Object Type: Article
System: The UNT Digital Library
Development and Testing of the Berkeley Darfur Stove (open access)

Development and Testing of the Berkeley Darfur Stove

None
Date: February 29, 2008
Creator: Amrose, Susan; Amrose, Susan; Kisch, G. Theodore; Kirubi, Charles; Woo, Jesse & Gadgil, Ashok
Object Type: Report
System: The UNT Digital Library
Quantification of seismic liquefaction risk (open access)

Quantification of seismic liquefaction risk

Explicit goals of acceptable risk for natural phenomena hazards (earthquake, extreme wind, and flood) have been established by the Department of Energy (DOE) 1994. Closely associated to the earthquake risk is the issue of seismically-induced liquefaction. Because deterministic methods currently available to answer the question to whether a site is liquefiable or not are incapable of providing a clue as to the likelihood or risk of liquefaction, the application of the criteria to a given facility requires that alternative evaluation techniques be formulated. This paper describes the application to a nuclear facility of a newly developed probabilistic methodology which rigorously accounts for geotechnical and seismologic uncertainties. The results of the analyses are compared with the acceptable levels of risk presented by DOE. This comparison is used to emphasize the power of the methodology as a tool in the decision-making processes.
Date: February 29, 1996
Creator: Arango, I.; Ostadan, F.; Lewis, M. R. & Gutierrez, B. J.
Object Type: Article
System: The UNT Digital Library
Continental Shelf Processes Affecting the Oceanography of the South Atlantic Bight. Progress Report, 1 June 1979-31 May 1980 (open access)

Continental Shelf Processes Affecting the Oceanography of the South Atlantic Bight. Progress Report, 1 June 1979-31 May 1980

The papers included in this progress report summarize some significant developments in understanding the South Atlantic Bight. Some of the results are summarized as follows: Onslow Bay flushing rates can be determined using a model based on an exponential dilution model; eddy induced nitrate flux accounts for most input of new nitrogen into shelf waters; and tarballs in the Gulf Stream are not transported to the nearshore because of an apparent inner shelf density front.
Date: February 29, 1980
Creator: Atkinson, L. P.
Object Type: Report
System: The UNT Digital Library
Continental Shelf Processes Affecting the Oceanography of the South Atlantic Bight. Progress Report, June 1, 1979-May 31, 1980 (open access)

Continental Shelf Processes Affecting the Oceanography of the South Atlantic Bight. Progress Report, June 1, 1979-May 31, 1980

Progress is reported on research conducted from June, 1979 to May, 1980 on various oceanographic aspects of the South Atlantic Bight. Research topics included: (1) A flashing model of Onslow Bay, North Carolina based on intrusion volumes; (2) A description of a bottom intrusion in Onslow Bay, North Carolina; (3) Detailed observations of a Gulf Stream spin-off eddy on the Georgia continental shelf; (4) Pelagic tar of Georgia and Florida; (5) A surface diaton bloom in response to eddy-forced upwelling; and (6) Hydrographic observations off Savannah and Brunswick, Georgia.
Date: February 29, 1980
Creator: Atkinson, L. P.
Object Type: Report
System: The UNT Digital Library
FINAL REPORT –INDEPENDENT VERIFICATION SURVEY SUMMARY AND RESULTS FOR THE ARGONNE NATIONAL LABORATORY BUILDING 330 PROJECT FOOTPRINT, ARGONNE, ILLINOIS (open access)

FINAL REPORT –INDEPENDENT VERIFICATION SURVEY SUMMARY AND RESULTS FOR THE ARGONNE NATIONAL LABORATORY BUILDING 330 PROJECT FOOTPRINT, ARGONNE, ILLINOIS

ORISE conducted onsite verification activities of the Building 330 project footprint during the period of June 6 through June 7, 2011. The verification activities included technical reviews of project documents, visual inspections, radiation surface scans, and sampling and analysis. The draft verification report was issued in July 2011 with findings and recommendations. The contractor performed additional evaluations and remediation.
Date: February 29, 2012
Creator: BAILEY, ERIKA N.
Object Type: Report
System: The UNT Digital Library
Tensile instabilities for porous plasticity models (open access)

Tensile instabilities for porous plasticity models

Several concepts (and assumptions) from the literature for porous metals and ceramics have been synthesized into a consistent model that predicts an admissibility limit on a material's porous yield surface. To ensure positive plastic work, the rate at which a yield surface can collapse as pores grow in tension must be constrained.
Date: February 29, 2000
Creator: BRANNON,REBECCA M.
Object Type: Article
System: The UNT Digital Library
Technology on In-Situ Gas Generation to Recover Residual Oil Reserves (open access)

Technology on In-Situ Gas Generation to Recover Residual Oil Reserves

This final technical report covers the period October 1, 1995 to February 29, 2008. This chapter begins with an overview of the history of Enhanced Oil Recovery techniques and specifically, CO2 flood. Subsequent chapters conform to the manner consistent with the Activities, Tasks, and Sub-tasks of the project as originally provided in Exhibit C1 in the Project Management Plan dated September 20, 1995. These chapters summarize the objectives, status and conclusions of the major project activities performed during the project period. The report concludes by describing technology transfer activities stemming from the project and providing a reference list of all publications of original research work generated by the project team or by others regarding this project. The overall objective of this project was a final research and development in the United States a technology that was developed at the Institute for Geology and Development of Fossil Fuels in Moscow, Russia. Before the technology can be convincingly adopted by United States oil and gas producers, the laboratory research was conducted at Mew Mexico Institute of Mining and Technology. The experimental studies were conducted to measure the volume and the pressure of the CO{sub 2} gas generated according to the new Russian …
Date: February 29, 2008
Creator: Bakhtiyarov, Sayavur
Object Type: Report
System: The UNT Digital Library
Organic Compounds in Fission Reactors. [Part] 2. Thorio-Organic Compounds (open access)

Organic Compounds in Fission Reactors. [Part] 2. Thorio-Organic Compounds

The advantages of the use of organic liquids in fission reactors to minmize corrosion and pressure problems were studied relative to the solution of thorium in such fluids. Thorio-organic compounds were prepared from organic acids, diketones, and other chelating compounds. Salts of carboxylic and phospho- organic acids were insoluble. The chelate with dibenzoylmethane was soluble in molten biphenyl but was decomposed at 300 deg C. The general low solubility of thorio-organic compounds in nonpolar solvents can be explained by steric effects. The large thorium atom has the ability to form strong coordination complexes with adjacent molecules, leading to coordination polymers. The effect can be minimized by shielding the thorium nucleus with large organic groups such as dibenzoylmethane. The large, branched organic groups needed to impart solubility limit the maximum solubility. (auth)
Date: February 29, 1960
Creator: Baldwin, W. H.
Object Type: Report
System: The UNT Digital Library
Enhanced Productivity of Chemical Processes Using Dense Fluidized Beds (open access)

Enhanced Productivity of Chemical Processes Using Dense Fluidized Beds

The work detailed in this report addresses Enabling Technologies within Computational Technology by integrating a “breakthrough” particle-fluid computational technology into traditional Process Science and Engineering Technology. The work completed under this DOE project addresses five major development areas 1) gas chemistry in dense fluidized beds 2) thermal cracking of liquid film on solids producing gas products 3) liquid injection in a fluidized bed with particle-to-particle liquid film transport 4) solid-gas chemistry and 5) first level validation of models. Because of the nature of the research using tightly coupled solids and fluid phases with a Lagrangian description of the solids and continuum description of fluid, the work provides ground-breaking advances in reactor prediction capability. This capability has been tested against experimental data where available. The commercial product arising out of this work is called Barracuda and is suitable for a wide (dense-to-dilute) range of industrial scale gas-solid flows with and without reactions. Commercial applications include dense gas-solid beds, gasifiers, riser reactors and cyclones.
Date: February 29, 2008
Creator: Banerjee, Sibashis; Chen, Alvin; Patel, Rutton; Snider, Dale; Williams, Ken; O'Hern, Timothy et al.
Object Type: Report
System: The UNT Digital Library
Recordkeeping in the decommissioning process (open access)

Recordkeeping in the decommissioning process

In the US, there are two sets of key decommissioning records clearly identified -- those that are essential for planning the D and D of a facility and then those that are the result of the decommissioning process itself. In some cases, the regulatory authorities require and in others advise the licensees of the records that may be useful or which are required to be kept from the decommissioning. In the remainder of the paper, the author attempts to highlight some important aspects of decommissioning recordkeeping.
Date: February 29, 2000
Creator: Boing, L. E.
Object Type: Article
System: The UNT Digital Library
An Experimental Investigation of a Prescription for Identifying Plastic Strain (open access)

An Experimental Investigation of a Prescription for Identifying Plastic Strain

A series of experiments is described in which a novel prescription for the identification of plastic strain is tested to determine its validity in the context of the strain-space formulation of rate-independent plasticity. Biaxial experiments were performed on several thin-walled aluminum 1100-O cylindrical specimens.
Date: February 29, 2000
Creator: Brown, A. A.; Casey, J. & Nikkel, D. J.
Object Type: Article
System: The UNT Digital Library
Direct Energy Conversion Fission Reactor Progress Report: December 1999-February 2000 (open access)

Direct Energy Conversion Fission Reactor Progress Report: December 1999-February 2000

OAK-B135 DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD DECEMBER 1,1999 THRIUGH FEBRUARY 29,2000
Date: February 29, 2000
Creator: Brown, L. C.
Object Type: Report
System: The UNT Digital Library
Production of cobalt-60 (open access)

Production of cobalt-60

Cobalt samples frequently are irradiated in nuclear reactors to produce gamma sources and can be irradiated as integral flux monitors because of the long half-life of the isotope produced. At the present time a small cobalt sample is being irradiated within the KW Reactor Snout facility for future use as a radiographic source for inspection of finished product in the Chemical Processing Department. Analysis was made to estimate the buildup of activity in this sample; the general equation may be of interest and value for other cobalt sample irradiations.
Date: February 29, 1960
Creator: Bunch, W. L.
Object Type: Report
System: The UNT Digital Library
ToHajiilee Economic Development, Inc.(TEDI) Feasibility Study for Utility-Scale Solar (open access)

ToHajiilee Economic Development, Inc.(TEDI) Feasibility Study for Utility-Scale Solar

To™Hajiilee Economic Development, Inc. (TEDI) is the economic development entity representing the ToHajiilee Chapter of the Navajo Nation, also known as the CaÃoncito Band of Navajo (CBN). Using DOE funding, TEDI assembled a team of qualified advisors to conduct a feasibility study for a utility-scale 30 MW Photovoltaic (PV) solar power generation facility on TEDI trust lands. The goal for this project has been to gather information and practical business commitments to successfully complete the feasibility analysis. The TEDI approach was to successively make informed decisions to select an appropriate technology best suited to the site, determine environmental viability of the site, secure options for the sale of generated power, determine practicality of transmission and interconnection of power to the local grid, and secure preliminary commitments on project financing. The feasibility study has been completed and provides TEDI with a practical understanding of its business options in moving forward with developing a solar project on CBN tribal lands. Funding from DOE has allowed TEDI and its team of professional advisors to carefully select technology and business partners and build a business model to develop this utility-scale solar project. As a result of the positive feasibility findings, TEDI is moving forward …
Date: February 29, 2012
Creator: Burpo, Rob
Object Type: Report
System: The UNT Digital Library
The program RADLST (Radiation Listing) (open access)

The program RADLST (Radiation Listing)

The program RADLST (Radiation Listing) is designed to calculate the nuclear and atomic radiations associated with the radioactive decay of nuclei. It uses as its primary input nuclear decay data in the Evaluated Nuclear Structure Data File (ENSDF) format. The code is written in FORTRAN 77 and, with a few exceptions, is consistent with the ANSI standard. 65 refs.
Date: February 29, 1988
Creator: Burrows, T.W.
Object Type: Report
System: The UNT Digital Library
The Mass Distribution and Assembly of the Milky Way from the Properties of the Magellanic Clouds (open access)

The Mass Distribution and Assembly of the Milky Way from the Properties of the Magellanic Clouds

We present a new measurement of the mass of the Milky Way (MW) based on observed properties of its largest satellite galaxies, the Magellanic Clouds (MCs), and an assumed prior of a {Lambda}CDM universe. The large, high-resolution Bolshoi cosmological simulation of this universe provides a means to statistically sample the dynamical properties of bright satellite galaxies in a large population of dark matter halos. The observed properties of the MCs, including their circular velocity, distance from the center of the MW, and velocity within the MW halo, are used to evaluate the likelihood that a given halo would have each or all of these properties; the posterior probability distribution function (PDF) for any property of the MW system can thus be constructed. This method provides a constraint on the MW virial mass, 1.2{sup +0.7} - {sub 0.4}(stat.){sup +0.3} - {sub 0.3}(sys.) x 10{sup 12} M {circle_dot} (68% confidence), which is consistent with recent determinations that involve very different assumptions. In addition, we calculate the posterior PDF for the density profile of the MW and its satellite accretion history. Although typical satellites of 10{sup 12} M {circle_dot} halos are accreted over a wide range of epochs over the last 10 Gyr, …
Date: February 29, 2012
Creator: Busha, Michael T.; Marshall, Philip J.; Wechsler, Risa H.; Klypin, Anatoly & Primack, Joel
Object Type: Article
System: The UNT Digital Library
Experimental-based modeling of a support structure as part of a full system model (open access)

Experimental-based modeling of a support structure as part of a full system model

Structural dynamic systems are often attached to a support structure to simulate proper boundary conditions during testing. In some cases the support structure is fairly simple and can be modeled by discrete springs and dampers. In other cases the desired test conditions necessitate the use of a support structural that introduces dynamics of its own. For such cases a more complex structural dynamic model is required to simulate the response of the full combined system. In this paper experimental frequency response functions, admittance function modeling concepts, and least squares reductions are used to develop a support structure model including both translational and rotational degrees of freedom at an attachment location. Subsequently, the modes of the support structure are estimated, and a NASTRAN model is created for attachment to the tested system.
Date: February 29, 2000
Creator: CARNE,THOMAS G. & DOHRMANN,CLARK R.
Object Type: Article
System: The UNT Digital Library
Final Scientific Report : Development of Transition Metal/ Chalcogen Based Cathode Catalysts for PEM Fuel Cells (open access)

Final Scientific Report : Development of Transition Metal/ Chalcogen Based Cathode Catalysts for PEM Fuel Cells

The aim of this project was to investigate the potential for using base metal sulfides and selenides as low cost replacements for precious metal catalysts, such as platinum, currently being used in PEM fuel cells. The approach was to deposit thin films of the materials to be evaluated onto inert electrodes and evaluate their activity for the cathode reaction (oxygen reduction) as well as ex-situ structural and compositional characterization. The most active materials identified are CoS2 and the 50:50 solid solution (Co,Ni)S2. However, the OCP of these materials is still considered too low, at 0.83V and 0.89V vs. RHE respectively, for testing in fuel cells. The methods employed here were necessary to compare with the activity of platinum as, when nano-dispersed on carbon supports, the active surface area of these materials is difficult to measure, making comparisons inaccurate. This research adds to the knowledge of potential candidates for platinum replacement in order to reduce the cost of PEM fuel cell technology and promote commercialization. Although the fabrication methods employed here are strictly experimental, methods were also developed to produce nano-dispersed catalysts with similar compositions, structure and activity. Cycling of these catalysts to highly oxidizing potentials resulted in an increase of …
Date: February 29, 2008
Creator: Campbell, Stephen, A.
Object Type: Report
System: The UNT Digital Library
Hydraulic test unit and plugs. [Quarterly] technical progress report No. 16, October 1, 1995--December 31, 1995 (open access)

Hydraulic test unit and plugs. [Quarterly] technical progress report No. 16, October 1, 1995--December 31, 1995

This report relates to fabrication of roll bar support structures and steam surface condenser seal plugs for power plants.
Date: February 29, 1996
Creator: Catapano, M.
Object Type: Report
System: The UNT Digital Library
Fusion Simulation Program (open access)

Fusion Simulation Program

Under this project, General Atomics (GA) was tasked to develop the experimental validation plans for two high priority ISAs, Boundary and Pedestal and Whole Device Modeling in collaboration with the theory, simulation and experimental communities. The following sections have been incorporated into the final FSP Program Plan (www.pppl.gov/fsp), which was delivered to the US Department of Energy (DOE). Additional deliverables by GA include guidance for validation, development of metrics to evaluate success and procedures for collaboration with experiments. These are also part of the final report.
Date: February 29, 2012
Creator: Chan), Project Staff (V.S.
Object Type: Report
System: The UNT Digital Library
EVALUATION OF ALTERNATE STAINLESS STEEL SURFACE TREATMENTS FOR MASS SPECTROSCOPY AND OTHER TRITIUM SYSTEMS (open access)

EVALUATION OF ALTERNATE STAINLESS STEEL SURFACE TREATMENTS FOR MASS SPECTROSCOPY AND OTHER TRITIUM SYSTEMS

There are specific components in the SRS Tritium Facilities that are required to introduce as few chemical impurities (such as protium and methane) as possible into the process gas. Two such components are the inlet systems for the mass spectroscopy facilities and hydrogen isotope mix standard containers. Two vendors now passivate stainless steel components for these systems, and both are relatively small businesses whose future viability can be questioned, which creates the need for new sources. Stainless steel containers were designed to evaluate alternate surface treatment vendors for tritium storage and handling for these high purity tritium systems. Five vendors applied their own 'best' surface treatments to two containers each - one was a current vendor, another was a chemical vapor deposited silicon coating, and the other three were electropolishing and chemical cleaning vendors. Pure tritium gas was introduced into all ten containers and the composition was monitored over time. The only observed impurities in the gas were some HT, less CT{sub 4}, and very small amounts of T{sub 2}O in all cases. The currently used vendor treated containers contained the least impurities. The chemical vapor deposited silicon treatment resulted in the highest impurity levels. Sampling one set of containers …
Date: February 29, 2012
Creator: Clark, E.; Mauldin, C. & Neikirk, K.
Object Type: Report
System: The UNT Digital Library