Confirmatory Survey Report for Area B1S/B2S at the Chevron Mining Washington Remediation Project, Washington, PA (open access)

Confirmatory Survey Report for Area B1S/B2S at the Chevron Mining Washington Remediation Project, Washington, PA

During the period of October 2 and 3, 2007, the Oak Ridge Institute for Science and Education (ORISE) performed confirmatory radiological survey activities which included gamma surface scans within Area B1S/B2S and the collection of soil samples from these areas.
Date: November 20, 2007
Creator: Adams, W. C.
Object Type: Report
System: The UNT Digital Library
U.S. Security Assistance to Lebanon (open access)

U.S. Security Assistance to Lebanon

This report discusses the variety of current U.S. security assistance programs to Lebanon including objectives, vetting processes, end-use monitoring, and issues for Congress. The last section of this report discusses the upcoming elections and the future of U.S. security assistance to Lebanon.
Date: May 20, 2009
Creator: Addis, Casey L.
Object Type: Report
System: The UNT Digital Library
Outlook and Challenges for Chinese Coal (open access)

Outlook and Challenges for Chinese Coal

China has been, is, and will continue to be a coal-powered economy. The rapid growth of coal demand since 2001 has created deepening strains and bottlenecks that raise questions about supply security. Although China's coal is 'plentiful,' published academic and policy analyses indicate that peak production will likely occur between 2016 and 2029. Given the current economic growth trajectory, domestic production constraints will lead to a coal gap that is not likely to be filled with imports. Urbanization, heavy industry growth, and increasing per-capita consumption are the primary drivers of rising coal usage. In 2006, the power sector, iron and steel, and cement accounted for 71% of coal consumption. Power generation is becoming more efficient, but even extensive roll-out of the highest efficiency units could save only 14% of projected 2025 coal demand. If China follows Japan, steel production would peak by 2015; cement is likely to follow a similar trajectory. A fourth wedge of future coal consumption is likely to come from the burgeoning coal-liquefaction and chemicals industries. New demand from coal-to-liquids and coal-to-chemicals may add 450 million tonnes of coal demand by 2025. Efficient growth among these drivers indicates that China's annual coal demand will reach 4.2 to …
Date: June 20, 2008
Creator: Aden, Nathaniel T.; Fridley, David G. & Zheng, Nina
Object Type: Report
System: The UNT Digital Library
Extraction of macro-molecule images in cryo-EM micrographs (open access)

Extraction of macro-molecule images in cryo-EM micrographs

Advances in Electron Microscopy and single-particle reconstruction have led to results at increasingly high resolutions. This has opened up the possibility of complete automation of single particle reconstruction. Main bottleneck in automation of single particle reconstruction is manual selection of particles in the micrograph. This paper describes a simple but efficient approach for segmentation of particle projections in the micrographs obtained using cryo-electron microscope. Changing the shape of objects to facilitate segmentation from the cluster and reconstructing its actual shape after isolation is successfully attempted. Both low-level and high-level processing techniques are used and the whole process is made automatic. Over 90 percent success in automatic particle picking is achieved. Several areas for improvement and future research directions are discussed.
Date: March 20, 2003
Creator: Adiga, Umesha P.S.; Malladi, Ravi & Glaeser, Robert M.
Object Type: Report
System: The UNT Digital Library
Finite Cosmology and a CMB Cold Spot (open access)

Finite Cosmology and a CMB Cold Spot

The standard cosmological model posits a spatially flat universe of infinite extent. However, no observation, even in principle, could verify that the matter extends to infinity. In this work we model the universe as a finite spherical ball of dust and dark energy, and obtain a lower limit estimate of its mass and present size: the mass is at least 5 x 10{sup 23}M{sub {circle_dot}} and the present radius is at least 50 Gly. If we are not too far from the dust-ball edge we might expect to see a cold spot in the cosmic microwave background, and there might be suppression of the low multipoles in the angular power spectrum. Thus the model may be testable, at least in principle. We also obtain and discuss the geometry exterior to the dust ball; it is Schwarzschild-de Sitter with a naked singularity, and provides an interesting picture of cosmogenesis. Finally we briefly sketch how radiation and inflation eras may be incorporated into the model.
Date: March 20, 2006
Creator: Adler, R. J.; Bjorken, J. D. & Overduin, J.M.
Object Type: Report
System: The UNT Digital Library
Design, Construction, and Operation of a Laboratory Scale Reactorfor the Production of High-Purity, Isotopically Enriched Bulksilicon (open access)

Design, Construction, and Operation of a Laboratory Scale Reactorfor the Production of High-Purity, Isotopically Enriched Bulksilicon

The design and operation of a recirculating flow reactor designed to convert isotopically enriched silane to polycrystalline Si with high efficiency and chemical purity is described. The starting material is SiF{sub 4}, which is enriched in the desired isotope by a centrifuge method and subsequently converted to silane. In the reactor, the silane is decomposed to silicon on the surface of a graphite starter rod (3 mm diameter) heated to 700-750 C. Flow and gas composition (0.3-0.5% silane in hydrogen) are chosen to minimize the generation of particles by homogeneous nucleation of silane and to attain uniform deposition along the length of the rod. Growth rates are 5 {micro}m/min, and the conversion efficiency is greater than 95%. A typical run produces 35 gm of polycrystalline Si deposited along a 150 mm length of the rod. After removal of the starter rod, dislocation-free single crystals are formed by the floating zone method. Crystals enriched in all 3 stable isotopes of Si have been made: {sup 28}Si (99.92%), {sup 29}Si (91.37%), and {sup 30}Si (88.25%). Concentrations of electrically active impurities (P and B) are as low as mid-10{sup 13} cm{sup -3}. Concentrations of C and O lie below 10{sup 16} and 10{sup …
Date: December 20, 2004
Creator: Ager, J. W., III; Beeman, J. W.; Hansen, W. L. & Haller, E. E.
Object Type: Report
System: The UNT Digital Library
[Letters from Mercedes Agogerio to the BRAC - June 20, 2005] (open access)

[Letters from Mercedes Agogerio to the BRAC - June 20, 2005]

Letters from Mercedes Agogerio to members of the Defense Base Closure and Realignment Commission (BRAC) pleading on behalf of Cannon Air Force Base in Clovis, New Mexico.
Date: June 20, 2005
Creator: Agogerio, Mercedes
Object Type: Letter
System: The UNT Digital Library
Trade and the Americas (open access)

Trade and the Americas

None
Date: March 20, 2003
Creator: Ahearn, Raymond J.
Object Type: Report
System: The UNT Digital Library
Trade and the Americas (open access)

Trade and the Americas

None
Date: September 20, 2002
Creator: Ahearn, Raymond J.
Object Type: Report
System: The UNT Digital Library
U.S.-European Union Trade Relations: Issues and Policy Challenges (open access)

U.S.-European Union Trade Relations: Issues and Policy Challenges

This report examines the economic partnership between the United States and the European Union. Not only is the U.S.-EU trade and investment relationship the largest in the world, but it is also arguably the most important. Agreement between the two partners in the past has been critical to making the world trading system more open and efficient.
Date: May 20, 2005
Creator: Ahearn, Raymond J.
Object Type: Report
System: The UNT Digital Library
U.S.-European Union Trade Relations: Issues and Policy Challenges (open access)

U.S.-European Union Trade Relations: Issues and Policy Challenges

None
Date: June 20, 2005
Creator: Ahearn, Raymond J.
Object Type: Report
System: The UNT Digital Library
U.S.-Thailand Free Trade Agreement Negotiations (open access)

U.S.-Thailand Free Trade Agreement Negotiations

Report on the trade agreements between the United States and Thailand, including commercial relations, intellectual property rights, and more.
Date: June 20, 2005
Creator: Ahearn, Raymond J. & Morrison, Wayne M.
Object Type: Report
System: The UNT Digital Library
Performing Neutron Cross-Section Measurements at RIA (open access)

Performing Neutron Cross-Section Measurements at RIA

The Rare Isotope Accelerator (RIA) is a proposed accelerator for the low energy nuclear physics community. Its goal is to understand the natural abundances of the elements heavier than iron, explore the nuclear force in systems far from stability, and study symmetry violation and fundamental physics in nuclei. To achieve these scientific goals, RIA promises to produce isotopes far from stability in sufficient quantities to allow experiments. It would also produce near stability isotopes at never before seen production rates, as much as 10{sup 12} pps. Included in these isotopes are many that are important to stockpile stewardship, such as {sup 87}Y, {sup 146-50}Eu, and {sup 231}Th. Given the expected production rates at RIA and a reasonably intense neutron source, one can expect to make {approx} 10 {micro}g targets of nuclei with a half-life of {approx}1 day. Thus, it will be possible at RIA to obtain experimental information on the neutron cross section for isotopes that have to date only been determined by theory. There are two methods to perform neutron cross-section measurements, prompt and delayed. The prompt method tries to measure each reaction as it happens. The exact technique employed will depend on the reaction of interest, (n,2n), (n,{gamma}), …
Date: May 20, 2003
Creator: Ahle, L. E.
Object Type: Report
System: The UNT Digital Library
A Neutron Source Facility for Neutron Cross-Section Measurements on Radioactive Targets at RIA (open access)

A Neutron Source Facility for Neutron Cross-Section Measurements on Radioactive Targets at RIA

The stockpile stewardship program is interested in neutron cross-section measurements on nuclei that are a few nucleons away from stability. Since neutron targets do not exist, radioactive targets are the only way to directly perform these measurements. This requires a facility that can provide high production rates for these short-lived nuclei as well as a source of neutrons. The Rare Isotope Accelerator (RIA) promises theses high production rates. Thus, adding a co-located neutron source facility to the RIA project baseline would allow these neutron cross-section measurements to be made. A conceptual design for such a neutron source has been developed, which would use two accelerators, a Dynamitron and a linac, to create the neutrons through a variety of reactions (d-d, d-t, deuteron break-up, p-Li). This range of reactions is needed in order to provide the desired energy range from 10's of keV to 20 MeV. The facility would also have hot cells to perform chemistry on the radioactive material both before and after neutron irradiation. The present status of this design and direction of future work will be discussed.
Date: May 20, 2003
Creator: Ahle, L. E.; Bernstein, L.; Rusnak, B. & Berio, R.
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
Tribological performance of NFC coatings under oil lubrication[Near Frictionless Carbon] (open access)

Tribological performance of NFC coatings under oil lubrication[Near Frictionless Carbon]

An increase in engine and vehicle efficiency usually requires an increase in the severity of contact at the interfaces of many critical components. Examples of such components include piston rings and cylinder liners in the engine, gears in the transmission and axle, bearings, etc. These components are oil-lubricated and require enhancement of their tribological performance. Argonne National Laboratory (ANL) recently developed a carbon-based coating with very low friction and wear properties. These near-frictionless-carbon (NFC) coatings have potential for application in various engine components for performance enhancement. This paper presents the study of the tribological performance of NFC-coated steel surfaces when lubricated with fully formulated and basestock synthetic oils. The NFC coatings reduced both the friction and wear of lubricated steel surfaces. The effect of the coating was much more pronounced in tests with basestock oil. This suggests that NFC-coated parts may not require heavily formulated lubricant oils to perform satisfactorily in terms of reliability and durability.
Date: January 20, 2000
Creator: Ajayi, O. O.; Alzoubi, M.; Erdemir, A.; Fenske, G. R.; Eryilmaz, O. L. & Zimmerman, S.
Object Type: Article
System: The UNT Digital Library
Thermal Analysis of SRF Cavity Couplers Using Parallel Multi physics Tool TEM3P (open access)

Thermal Analysis of SRF Cavity Couplers Using Parallel Multi physics Tool TEM3P

SLAC has developed a multi-physics simulation code TEM3P for simulating integrated effects of electromagnetic, thermal and structural loads. TEM3P shares the same software infrastructure with SLAC's parallel finite element electromagnetic codes, thus enabling all physics simulations within a single framework. The finite-element approach allows high-fidelity, high-accuracy simulations and the parallel implementation facilitates large-scale computation with fast turnaround times. In this paper, TEM3P is used to analyze thermal loading at coupler end of the JLAB SRF cavity.
Date: May 20, 2009
Creator: Akcelik, V; Lee, L. Q.; Li, Z.; Ng, C. K.; Ko, K.; Cheng, G. et al.
Object Type: Article
System: The UNT Digital Library
PRODUCTION OF NEW BIOMASS/WASTE-CONTAINING SOLID FUELS (open access)

PRODUCTION OF NEW BIOMASS/WASTE-CONTAINING SOLID FUELS

CQ Inc. and its team members (ALSTOM Power Inc., Bliss Industries, McFadden Machine Company, and industry advisors from coal-burning utilities, equipment manufacturers, and the pellet fuels industry) addressed the objectives of the Department of Energy and industry to produce economical, new solid fuels from coal, biomass, and waste materials that reduce emissions from coal-fired boilers. This project builds on the team's commercial experience in composite fuels for energy production. The electric utility industry is interested in the use of biomass and wastes as fuel to reduce both emissions and fuel costs. In addition to these benefits, utilities also recognize the business advantage of consuming the waste byproducts of customers both to retain customers and to improve the public image of the industry. Unfortunately, biomass and waste byproducts can be troublesome fuels because of low bulk density, high moisture content, variable composition, handling and feeding problems, and inadequate information about combustion and emissions characteristics. Current methods of co-firing biomass and wastes either use a separate fuel receiving, storage, and boiler feed system, or mass burn the biomass by simply mixing it with coal on the storage pile. For biomass or biomass-containing composite fuels to be extensively used in the U.S., especially …
Date: April 20, 2001
Creator: Akers, David J.; Shirey, Glenn A.; Zitron, Zalman & Maney, Charles Q.
Object Type: Report
System: The UNT Digital Library
Fast Ignition Experimental and Theoretical Studies (open access)

Fast Ignition Experimental and Theoretical Studies

We are becoming dependent on energy more today than we were a century ago, and with increasing world population and booming economies, sooner or later our energy sources will be exhausted. Moreover, our economy and welfare strongly depends on foreign oil and in the shadow of political uncertainties, there is an urgent need for a reliable, safe, and cheap energy source. Thermonuclear fusion, if achieved, is that source of energy which not only will satisfy our demand for today but also for centuries to come. Today, there are two major approaches to achieve fusion: magnetic confinement fusion (MFE) and inertial confinement fusion (ICF). This dissertation explores the inertial confinement fusion using the fast ignition concept. Unlike the conventional approach where the same laser is used for compression and ignition, in fast ignition separate laser beams are used. This dissertation addresses three very important topics to fast ignition inertial confinement fusion. These are laser-to-electron coupling efficiency, laser-generated electron beam transport, and the associated isochoric heating. First, an integrated fast ignition experiment is carried out with 0.9 kJ of energy in the compression beam and 70 J in the ignition beam. Measurements of absolute K{sub {alpha}} yield from the imploded core revealed …
Date: October 20, 2006
Creator: Akli, K
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Commissioning of the LCLS Linac and Bunch Compressors (open access)

Commissioning of the LCLS Linac and Bunch Compressors

The Linac Coherent Light Source (LCLS) is a SASE x-ray Free-Electron Laser (FEL) project under construction at SLAC [1]. The injector section, from drive-laser and RF photocathode gun through the first bunch compressor, was commissioned in the spring and summer of 2007. The second phase of commissioning, including the second bunch compressor and various main linac modifications, was completed in January through August of 2008. We report here on experience gained during this second phase of machine commissioning, including the injector, the first and second bunch compressor stages, the linac up to 14 GeV, and beam stability measurements. The final commissioning phase, including the undulator and the long transport line from the linac, is set to begin in December 2008, with first light expected in July 2009.
Date: August 20, 2008
Creator: Akre, R.; Brachmann, A.; Decker, F.-J.; Ding, Y.; Dowell, D.; Emma#, P. et al.
Object Type: Article
System: The UNT Digital Library
Laboratory Directed Research and Development FY2001 Annual Report (open access)

Laboratory Directed Research and Development FY2001 Annual Report

Established by Congress in 1991, the Laboratory Directed Research and Development (LDRD) Program provides the Department of Energy (DOE)/National Nuclear Security Administration (NNSA) laboratories, like Lawrence Livermore National Laboratory (LLNL or the Laboratory), with the flexibility to invest up to 6% of their budget in long-term, high-risk, and potentially high payoff research and development (R&D) activities to support the DOE/NNSA's national security missions. By funding innovative R&D, the LDRD Program at LLNL develops and extends the Laboratory's intellectual foundations and maintains its vitality as a premier research institution. As proof of the Program's success, many of the research thrusts that started many years ago under LDRD sponsorship are at the core of today's programs. The LDRD Program, which serves as a proving ground for innovative ideas, is the Laboratory's most important single resource for fostering excellent science and technology for today's needs and tomorrow's challenges. Basic and applied research activities funded by LDRD enhance the Laboratory's core strengths, driving its technical vitality to create new capabilities that enable LLNL to meet DOE/NNSA's national security missions. The Program also plays a key role in building a world-class multidisciplinary workforce by engaging the Laboratory's best researchers, recruiting its future scientists and engineers, …
Date: June 20, 2002
Creator: Al-Ayat, R
Object Type: Report
System: The UNT Digital Library
Laminin and biomimetic extracellular elasticity enhance functional differentiation in mammary epithelia (open access)

Laminin and biomimetic extracellular elasticity enhance functional differentiation in mammary epithelia

In the mammary gland, epithelial cells are embedded in a 'soft' environment and become functionally differentiated in culture when exposed to a laminin-rich extracellular matrix gel. Here, we define the processes by which mammary epithelial cells integrate biochemical and mechanical extracellular cues to maintain their differentiated phenotype. We used single cells cultured on top of gels in conditions permissive for {beta}-casein expression using atomic force microscopy to measure the elasticity of the cells and their underlying substrata. We found that maintenance of {beta}-casein expression required both laminin signalling and a 'soft' extracellular matrix, as is the case in normal tissues in vivo, and biomimetic intracellular elasticity, as is the case in primary mammary epithelial organoids. Conversely, two hallmarks of breast cancer development, stiffening of the extracellular matrix and loss of laminin signalling, led to the loss of {beta}-casein expression and non-biomimetic intracellular elasticity. Our data indicate that tissue-specific gene expression is controlled by both the tissues unique biochemical milieu and mechanical properties, processes involved in maintenance of tissue integrity and protection against tumorigenesis.
Date: October 20, 2008
Creator: Alcaraz, Jordi; Xu, Ren; Mori, Hidetoshi; Nelson, Celeste M.; Mroue, Rana; Spencer, Virginia A. et al.
Object Type: Article
System: The UNT Digital Library
Small Column Ion Exchange Analysis for Removal of Cesium from SRS Low Curie Salt Solutions Using Crystalline Silicotitanate (CST) Resin (open access)

Small Column Ion Exchange Analysis for Removal of Cesium from SRS Low Curie Salt Solutions Using Crystalline Silicotitanate (CST) Resin

Savannah River Technology Center (SRTC) researchers modeled ion exchange removal of cesium from dissolved salt waste solutions. The results assist in evaluating proposed configurations for an ion exchange process to remove residual cesium from low curie waste streams. A process for polishing (i.e., removing small amounts) of cesium may prove useful should supernate draining fail to meet the Low Curie Salt (LCS) target limit of 0.1 Ci of Cs-137 per gallon of salt solution. Cesium loading isotherms and column breakthrough curves for Low Curie dissolved salt solutions were computed to provide performance predictions for various column designs.
Date: April 20, 2004
Creator: Aleman, Sebastian E. & Hamm, L. L.
Object Type: Report
System: The UNT Digital Library
Gray Wolves Under the Endangered Species Act (ESA): Distinct Population Segments and Experimental Populations (open access)

Gray Wolves Under the Endangered Species Act (ESA): Distinct Population Segments and Experimental Populations

This report looks at the distinct population segments (DPSs) process as it is applied to the gray wolf. It also reviews experimental populations of wolves under the Endangered Species Act (ESA) and their protections.
Date: October 20, 2008
Creator: Alexander, Kristina & Corn, M. Lynne
Object Type: Report
System: The UNT Digital Library