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Mister Martini: Poems

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Spare yet evocative, the poems in Mister Martini pair explorations of a father-son relationship with haiku-like martini recipes. The martini becomes a daring metaphor for this relationship as it moves from the son’s childhood to the father’s death. Each poem is a strong drink in its own right, and together they form a potent narrative of alienation and love between a father and son struggling to communicate. “This is a truly original book. There’s nothing extra: sharp and clear and astonishing. Viva!” —Naomi Shihab Nye, judge and author of 19 Varieties of Gazelle
Date: April 15, 2008
Creator: Carr, Richard
Object Type: Book
System: The UNT Digital Library
Defense Management: Observations on DOD's FY 2009 Budget Request for Corrosion Prevention and Control (open access)

Defense Management: Observations on DOD's FY 2009 Budget Request for Corrosion Prevention and Control

Correspondence issued by the Government Accountability Office with an abstract that begins "This letter formally responds to section 371 of the National Defense Authorization Act for Fiscal Year 2008. The act requires GAO to provide an analysis of the Department of Defense's (DOD) budget submission for corrosion control and prevention and a DOD report that was to be submitted with defense budget materials to the congressional defense committees within 60 days after submission of the budget for a fiscal year. On April 3, 2008, we provided the briefing to staff of Congressional committees to satisfy the mandate and 60-day reporting requirement."
Date: April 15, 2008
Creator: United States. Government Accountability Office.
Object Type: Text
System: The UNT Digital Library
2010 Census: Bureau Needs to Specify How It Will Assess Coverage Follow-up Techniques and When It Will Produce Coverage Measurement Results (open access)

2010 Census: Bureau Needs to Specify How It Will Assess Coverage Follow-up Techniques and When It Will Produce Coverage Measurement Results

A letter report issued by the Government Accountability Office with an abstract that begins "An accurate decennial census relies on finding and counting people--only once--in the right place and collecting complete and correct information. GAO reviewed the Department of Commerce's U.S. Census Bureau's (Bureau) plans to (1) improve the census's accuracy--or coverage--with its coverage follow-up operation, (2) assess the accuracy of the census through its census coverage measurement program, and (3) evaluate these efforts after 2010. GAO reviewed documentation and interviewed Bureau officials about the Bureau's coverage follow-up and measurement plans. GAO compared plans for measuring coverage in 2000 and 2010 and interviewed 15 experts about changes to the plans."
Date: April 15, 2008
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
Highlights of a Forum Convened by the Comptroller General of the United States: Strengthening the Use of Risk Management Principles in Homeland Security (open access)

Highlights of a Forum Convened by the Comptroller General of the United States: Strengthening the Use of Risk Management Principles in Homeland Security

Other written product issued by the Government Accountability Office with an abstract that begins "From the terrorist attacks of September 11, 2001, to Hurricane Katrina, homeland security risks vary widely. The nation can neither achieve total security nor afford to protect everything against all risks. Managing these risks is especially difficult in today's environment of globalization, increasing security interdependence, and growing fiscal challenges for the federal government. It is increasingly important that organizations effectively target homeland security funding--totaling nearly $65 billion in 2008 federal spending alone--to address the nation's most critical priorities. GAO convened a forum of experts on October 25, 2007, to advance a national dialogue on applying risk management to homeland security. Broadly defined, risk management is a process that helps policymakers assess risk, strategically allocate finite resources, and take actions under conditions of uncertainty. Participants included federal, state, and local officials and risk management experts from the private sector and academia. The forum addressed effective practices, challenges federal agencies face in applying risk management to homeland security, and actions that can strengthen homeland security risk management. Comments expressed during the proceedings do not necessarily represent the views of any one participant, the organizations they represent, or GAO. …
Date: April 15, 2008
Creator: United States. Government Accountability Office.
Object Type: Text
System: The UNT Digital Library
Drinking Water: The District of Columbia and Communities Nationwide Face Serious Challenges in Their Efforts to Safeguard Water Supplies (open access)

Drinking Water: The District of Columbia and Communities Nationwide Face Serious Challenges in Their Efforts to Safeguard Water Supplies

Testimony issued by the Government Accountability Office with an abstract that begins "The discovery in 2004 of lead contamination in the District of Columbia's drinking water resulted in an administrative order between the Environmental Protection Agency (EPA) and the District's Water and Sewer Authority (WASA), requiring WASA to take a number of corrective actions. WASA also took additional, longer-term measures, most notably a roughly $400 million program to replace what may be 35,000 lead service lines in public space within its service area. As in WASA's case, water utilities nationwide are under increasing pressure to make significant investments to upgrade aging and deteriorating infrastructures, improve security, serve a growing population, and meet new regulatory requirements. In this context, GAO's testimony presents observations on (1) WASA's efforts to address lead contamination in light of its other pressing water infrastructure needs, and (2) the extent to which WASA's challenges are indicative of those facing water utilities nationwide. To address these issues, GAO relied primarily on its 2005 and 2006 reports on lead contamination in drinking water, as well as other recent GAO reports examining the nation's water infrastructure needs and strategies to address these needs."
Date: April 15, 2008
Creator: United States. Government Accountability Office.
Object Type: Text
System: The UNT Digital Library
Transportation Security: Efforts to Strengthen Aviation and Surface Transportation Security Continue to Progress, but More Work Remains (open access)

Transportation Security: Efforts to Strengthen Aviation and Surface Transportation Security Continue to Progress, but More Work Remains

Testimony issued by the Government Accountability Office with an abstract that begins "Within the Department of Homeland Security (DHS), the Transportation Security Administration's (TSA) mission is to protect the nation's transportation network. Since its inception in 2001, TSA has developed and implemented a variety of programs and procedures to secure commercial aviation and surface modes of transportation. Other DHS components, federal agencies, state and local governments, and the private sector also play a role in transportation security. GAO has examined (1) the progress TSA and other DHS components have made in securing the nation's aviation and surface transportation systems, and the challenges that remain, and (2) crosscutting issues that have impeded TSA's efforts in strengthening security. This testimony is based on GAO reports and testimonies issued from February 2004 to February 2008 and ongoing work regarding the security of the nation's aviation and surface transportation systems, as well as selected updates to this work conducted in April 2008. To conduct this work, GAO reviewed documents related to TSA security efforts and interviewed TSA and transportation industry officials."
Date: April 15, 2008
Creator: United States. Government Accountability Office.
Object Type: Text
System: The UNT Digital Library
PREDICTION OF CHARACTERISTIC LENGTH AND FRACTURE TOUGHNESS IN DUCTILE-BRITTLE TRANSITION (open access)

PREDICTION OF CHARACTERISTIC LENGTH AND FRACTURE TOUGHNESS IN DUCTILE-BRITTLE TRANSITION

Finite element method was used to analyze the three-point bend experimental data of A533B-1 pressure vessel steel obtained by Sherry, Lidbury, and Beardsmore [1] from -160 to -45 C within the ductile-brittle transition regime. As many researchers have shown, the failure stress ({sigma}{sub f}) of the material could be approximated as a constant. The characteristic length, or the critical distance (r{sub c}) from the crack tip, at which {sigma}{sub f} is reached, is shown to be temperature dependent based on the crack tip stress field calculated by the finite element method. With the J-A{sub 2} two-parameter constraint theory in fracture mechanics, the fracture toughness (J{sub C} or K{sub JC}) can be expressed as a function of the constraint level (A{sub 2}) and the critical distance r{sub c}. This relationship is used to predict the fracture toughness of A533B-1 in the ductile-brittle transition regime with a constant {sigma}{sub f} and a set of temperature-dependent r{sub c}. It can be shown that the prediction agrees well with the test data for wide range of constraint levels from shallow cracks (a/W= 0.075) to deep cracks (a/W= 0.5), where a is the crack length and W is the specimen width.
Date: April 15, 2008
Creator: Lam, P
Object Type: Article
System: The UNT Digital Library
LUsim: A Framework for Simulation-Based Performance Modelingand Prediction of Parallel Sparse LU Factorization (open access)

LUsim: A Framework for Simulation-Based Performance Modelingand Prediction of Parallel Sparse LU Factorization

Sparse parallel factorization is among the most complicated and irregular algorithms to analyze and optimize. Performance depends both on system characteristics such as the floating point rate, the memory hierarchy, and the interconnect performance, as well as input matrix characteristics such as such as the number and location of nonzeros. We present LUsim, a simulation framework for modeling the performance of sparse LU factorization. Our framework uses micro-benchmarks to calibrate the parameters of machine characteristics and additional tools to facilitate real-time performance modeling. We are using LUsim to analyze an existing parallel sparse LU factorization code, and to explore a latency tolerant variant. We developed and validated a model of the factorization in SuperLU_DIST, then we modeled and implemented a new variant of slud, replacing a blocking collective communication phase with a non-blocking asynchronous point-to-point one. Our strategy realized a mean improvement of 11percent over a suite of test matrices.
Date: April 15, 2008
Creator: Univ. of California, San Diego
Object Type: Article
System: The UNT Digital Library
Correlations and Fluctuations: Status and Perspectives (open access)

Correlations and Fluctuations: Status and Perspectives

We will provide an overview of the physics which can be addressed by studying fluctuations and correlations in heavy ion collisions. Observables, which have been discussed in the literature will be briefly reviewed and put in context with experiment and information from Lattice QCD. Special attention will be given to the QCD critical point and the first order co-existence region.
Date: April 15, 2008
Creator: Koch, Volker & Koch, Volker
Object Type: Article
System: The UNT Digital Library
Joint inversion of crosshole radar and seismic traveltimes acquired at the South Oyster BacterialTransport Site (open access)

Joint inversion of crosshole radar and seismic traveltimes acquired at the South Oyster BacterialTransport Site

The structural approach to joint inversion, entailing common boundaries or gradients, offers a flexible way to invert diverse types of surface-based and/or crosshole geophysical data. The cross-gradients function has been introduced as a means to construct models in which spatial changes in two models are parallel or anti-parallel. Inversion methods that use such structural constraints also provide estimates of non-linear and non-unique field-scale relationships between model parameters. Here, we invert jointly crosshole radar and seismic traveltimes for structurally similar models using an iterative non-linear traveltime tomography algorithm. Application of the inversion scheme to synthetic data demonstrates that it better resolves lithological boundaries than the individual inversions. Tests of the scheme on observed radar and seismic data acquired within a shallow aquifer illustrate that the resultant models have improved correlations with flowmeter data than with models based on individual inversions. The highest correlation with the flowmeter data is obtained when the joint inversion is combined with a stochastic regularization operator, where the vertical integral scale is estimated from the flowmeter data. Point-spread functions shows that the most significant resolution improvements of the joint inversion is in the horizontal direction.
Date: April 15, 2008
Creator: Linde, Niklas; Tryggvason, Ari; Peterson, John & Hubbard, Susan
Object Type: Article
System: The UNT Digital Library
Implementation of an interactive matching scheme for the Kapchinskij-Vladimirskij equations in the WARP code (open access)

Implementation of an interactive matching scheme for the Kapchinskij-Vladimirskij equations in the WARP code

The WARP code is a robust electrostatic particle-in-cell simulation package used to model charged particle beams with strong space-charge forces. A fundamental operation associated with seeding detailed simulations of a beam transport channel is to generate initial conditions where the beam distribution is matched to the structure of a periodic focusing lattice. This is done by solving for periodic, matched solutions to a coupled set of ODEs called the Kapchinskij-Vladimirskij (KV) envelope equations, which describe the evolution of low-order beam moments subject to applied lattice focusing, space-charge defocusing, and thermal defocusing forces. Recently, an iterative numerical method was developed (Lund, Chilton, and Lee, Efficient computation of matched solutions to the KV envelope equations for periodic focusing lattices, Physical Review Special Topics-Accelerators and Beams 9, 064201 2006) to generate matching conditions in a highly flexible, convergent, and fail-safe manner. This method is extended and implemented in the WARP code as a Python package to vastly ease the setup of detailed simulations. In particular, the Python package accommodates any linear applied lattice focusing functions without skew coupling, and a more general set of beam parameter specifications than its predecessor. Lattice strength iteration tools were added to facilitate the implementation of problems with …
Date: April 15, 2008
Creator: Chilton, Sven H.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Dust Studies in DIII-D Tokamak (open access)

Dust Studies in DIII-D Tokamak

Studies of submicron dust using Mie scattering from Nd:YAG lasers and video data of micron to sub-millimeter sized dust on DIII-D tokamak have provided the first data of dust sources and transport during tokamak discharges. During normal operation on DIII-D dust observation rates are low, a few events per discharge or less. The net carbon content of the dust corresponds to a carbon atom density a few orders of magnitude below the core impurity density. Statistical analysis of Mie data collected over months of operation reveal correlation of increased dust rate with increased heating power and impulsive wall loading due to edge localized modes (ELMs) and disruptions. Generation of significant amounts of dust by disruptions is confirmed by the camera data. However, dust production by disruptions alone is insufficient to account for estimated in-vessel dust inventory in DIII-D. After an extended entry vent, thousands of dust particles are observed by cameras in the first 2-3 plasma discharges. Individual particles moving at velocities up to {approx}300 m/s, breakup of larger particles into pieces, and collisions of particles with walls are observed. After {approx}70 discharges, dust levels are reduced to a few events per discharge. In order to calibrate diagnostics and benchmark …
Date: April 15, 2008
Creator: Rudakov, D. L.; West, W. P.; Groth, M.; Yu, J. H.; Boedo, J. A.; Bray, B. D. et al.
Object Type: Article
System: The UNT Digital Library
Evaluation of the 2007 Toyota Camry Hybrid Syneregy Drive System (open access)

Evaluation of the 2007 Toyota Camry Hybrid Syneregy Drive System

The U.S. Department of Energy (DOE) and American automotive manufacturers General Motors, Ford, and DaimlerChrysler began a five-year, cost-shared partnership in 1993. Currently, hybrid electric vehicle (HEV) research and development is conducted by DOE through its FreedomCAR and Vehicle Technologies (FCVT) program. The mission of the FCVT program is to develop more energy efficient and environmentally friendly highway transportation technologies. Program activities include research, development, demonstration, testing, technology validation, and technology transfer. These activities are aimed at developing technologies that can be domestically produced in a clean and cost-competitive manner. Under the FCVT program, support is provided through a three-phase approach [1] which is intended to: • Identify overall propulsion and vehicle-related needs by analyzing programmatic goals and reviewing industry’s recommendations and requirements, then develop the appropriate technical targets for systems, subsystems, and component research and development activities; • Develop and validate individual subsystems and components, including electric motors, emission control devices, battery systems, power electronics, accessories, and devices to reduce parasitic losses; and • Determine how well the components and subassemblies work together in a vehicle environment or as a complete propulsion system and whether the efficiency and performance targets at the vehicle level have been achieved. The research …
Date: April 15, 2008
Creator: Burress, T. A.; Coomer, C. L.; Campbell, S. L.; Seiber, L. E.; Marlino, L. D.; Staunton, R. H. et al.
Object Type: Report
System: The UNT Digital Library
The Use of Horizontal Wells in Gas Production from Hydrate Accumulations (open access)

The Use of Horizontal Wells in Gas Production from Hydrate Accumulations

The amounts of hydrocarbon gases trapped in natural hydrate accumulations are enormous, leading to a recent interest in the evaluation of their potential as an energy source. Earlier studies have demonstrated that large volumes of gas can be readily produced at high rates for long times from gas hydrate accumulations by means of depressurization-induced dissociation, using conventional technology and vertical wells. The results of this numerical study indicate that the use of horizontal wells does not confer any practical advantages to gas production from Class 1 deposits. This is because of the large disparity in permeabilities between the hydrate layer (HL) and the underlying free gas zone, leading to a hydrate dissociation that proceeds in a horizontally dominant direction and is uniform along the length of the reservoir. When horizontal wells are placed near the base of the HL in Class 2 deposits, the delay in the evolution of a significant gas production rate outweighs their advantages, which include higher rates and the prevention of flow obstruction problems that often hamper the performance of vertical wells. Conversely, placement of a horizontal well near to top of the HL can lead to dramatic increases in gas production from Class 2 and …
Date: April 15, 2008
Creator: Reagan, Matthew; Moridis, George J.; Reagan, Matthew T. & Zhang, Keni
Object Type: Article
System: The UNT Digital Library
Electronic contribution to friction on GaAs (open access)

Electronic contribution to friction on GaAs

The electronic contribution to friction at semiconductor surfaces was investigated by using a Pt-coated tip with 50nm radius in an atomic force microscope sliding against an n-type GaAs(100) substrate. The GaAs surface was covered by an approximately 1 nm thick oxide layer. Charge accumulation or depletion was induced by the application of forward or reverse bias voltages. We observed a substantial increase in friction force in accumulation (forward bias) with respect to depletion (reverse bias). We propose a model based on the force exerted by the trapped charges that quantitatively explains the experimental observations of excess friction.
Date: April 15, 2008
Creator: Applied Science and Technology Graduate Group, UC Berkeley; Dept. of Materials Sciences and Engineering, UC Berkeley; Salmeron, Miquel; Qi, Yabing; Park, J.Y.; Hendriksen, B.L.M. et al.
Object Type: Article
System: The UNT Digital Library
Continuation of Studies on Development of ODS Heat Exchanger Tubing (open access)

Continuation of Studies on Development of ODS Heat Exchanger Tubing

The Department of Energy (DOE), National Energy Technology Center (NETL), has initiated a strategic plan for the development of advanced technologies needed to design and build fossil fuel plants with very high efficiency and environmental performance. These plants, referred to as 'Vision 21' and FutureGen programs by DOE, will produce electricity, chemicals, fuels, or a combination of these products, and possibly secondary products such as steam/heat for industrial use. MA956 is a prime candidate material being considered for a high temperature heat exchanger in the 'Vision 21' and FutureGen programs. This material is an oxide dispersion strengthened (ODS) alloy; however, there are some gaps in the data required to commit to the use of these alloys in a full-size plant. To fill the technology gaps for commercial production and use of the material for 'Advanced Power Generation Systems' this project has performed development activity to significant increase in circumferential strength of MA956 as compared to currently available material, investigated bonding technologies for bonding tube-to-tube joints through joining development, and performed tensile, creep and fire-side corrosion tests to validate the use and fabrication processes of MA956 to heat exchanger tubing applications. Development activities within this projected has demonstrated increased circumferential strength …
Date: April 15, 2008
Creator: Brown, Lawrence; Workman, David; Kad, Bimal; Smith, Gaylord; Robertson, Archie & Wright, Ian
Object Type: Report
System: The UNT Digital Library
Modeling of Oceanic Gas Hydrate Instability and Methane Release in Response to Climate Change (open access)

Modeling of Oceanic Gas Hydrate Instability and Methane Release in Response to Climate Change

Paleooceanographic evidence has been used to postulate that methane from oceanic hydrates may have had a significant role in regulating global climate, implicating global oceanic deposits of methane gas hydrate as the main culprit in instances of rapid climate change that have occurred in the past. However, the behavior of contemporary oceanic methane hydrate deposits subjected to rapid temperature changes, like those predicted under future climate change scenarios, is poorly understood. To determine the fate of the carbon stored in these hydrates, we performed simulations of oceanic gas hydrate accumulations subjected to temperature changes at the seafloor and assessed the potential for methane release into the ocean. Our modeling analysis considered the properties of benthic sediments, the saturation and distribution of the hydrates, the ocean depth, the initial seafloor temperature, and for the first time, estimated the effect of benthic biogeochemical activity. The results show that shallow deposits--such as those found in arctic regions or in the Gulf of Mexico--can undergo rapid dissociation and produce significant methane fluxes of 2 to 13 mol/yr/m{sup 2} over a period of decades, and release up to 1,100 mol of methane per m{sup 2} of seafloor in a century. These fluxes may exceed the …
Date: April 15, 2008
Creator: Reagan, Matthew; Reagan, Matthew T. & Moridis, George J.
Object Type: Article
System: The UNT Digital Library
Deflagration Behavior of PBX 9501 at Elevated Temperature and Pressure (open access)

Deflagration Behavior of PBX 9501 at Elevated Temperature and Pressure

We report the deflagration behavior of PBX 9501 at pressures up to 300 MPa and temperatures of 150-180 C where the sample has been held at the test temperature for several hours before ignition. The purpose is to determine the effect on the deflagration behavior of material damage caused by prolonged exposure to high temperature. This conditioning is similar to that experienced by an explosive while it being heated to eventual explosion. The results are made more complicated by the presence of a significant thermal gradient along the sample during the temperature ramp and soak. Three major conclusions are: the presence of nitroplasticizer makes PBX 9501 more thermally sensitive than LX-04 with an inert Viton binder; the deflagration behavior of PBX 9501 is more extreme and more inconsistent than that of LX-04; and something in PBX 9501 causes thermal damage to 'heal' as the deflagration proceeds, resulting in a decelerating deflagration front as it travels along the sample.
Date: April 15, 2008
Creator: Maienschein, J L & Koerner, J G
Object Type: Article
System: The UNT Digital Library
CRITICALITY HAZOP EFFICIENTLY EVALUATING HAZARDS OF NEW OR REVISED CRITICALITY SAFETY EVALUATIONS (open access)

CRITICALITY HAZOP EFFICIENTLY EVALUATING HAZARDS OF NEW OR REVISED CRITICALITY SAFETY EVALUATIONS

The 'Criticality HazOp' technique, as developed at Hanford's Plutonium Finishing Plant (PFP), has allowed for efficiencies enabling shortening of the time necessary to complete new or revised criticality safety evaluation reports (CSERs). For example, in the last half of 2007 at PFP, CSER revisions undergoing the 'Criticality HazOp' process were completed at a higher rate than previously achievable. The efficiencies gained through use of the 'Criticality HazOp' process come from the preliminary narrowing of potential scenarios for the Criticality analyst to fully evaluate in preparation of the new or revised CSER, and from the use of a systematized 'Criticality HazOp' group assessment of the relevant conditions to show which few parameter/condition/deviation combinations actually require analytical effort. The 'Criticality HazOp' has not only provided efficiencies of time, but has brought to criticality safety evaluation revisions the benefits of a structured hazard evaluation method and the enhanced insight that may be gained from direct involvement of a team in the process. In addition, involved personnel have gained a higher degree of confidence and understanding of the resulting CSER product.
Date: April 15, 2008
Creator: DM, CARSON
Object Type: Article
System: The UNT Digital Library
ADVANCED WAVEFORM SIMULATION FOR SEISMIC MONITORING EVENTS (open access)

ADVANCED WAVEFORM SIMULATION FOR SEISMIC MONITORING EVENTS

The recent Nevada Earthquake (M=6) produced an extraordinary set of crustal guided waves. In this study, we examine the three-component data at all the USArray stations in terms of how well existing models perform in predicting the various phases, Rayleigh waves, Love waves, and Pnl waves. To establish the source parameters, we applied the Cut and Paste Code up to distance of 5° for an average local crustal model which produced a normal mechanism (strike=35°,dip=41°,rake=-85°) at a depth of 9 km and Mw=5.9. Assuming this mechanism, we generated synthetics at all distances for a number of 1D and 3D models. The Pnl observations fit the synthetics for the simple models well both in timing (VPn=7.9km/s) and waveform fits out to a distance of about 5°. Beyond this distance a great deal of complexity can be seen to the northwest apparently caused by shallow subducted slab material. These paths require considerable crustal thinning and higher P-velocities. Small delays and advances outline the various tectonic province to the south, Colorado Plateau, etc. with velocities compatible with that reported on by Song et al.(1996). Five-second Rayleigh waves (Airy Phase) can be observed throughout the whole array and show a great deal of variation …
Date: April 15, 2008
Creator: Helmberger, Donald V.; Tromp, Jeroen & Rodgers, Arthur J.
Object Type: Report
System: The UNT Digital Library
Slurry Pump Mixing Effectiveness in Tank 50h (open access)

Slurry Pump Mixing Effectiveness in Tank 50h

Computational Fluid Dynamics (CFD) models of Tank 50 with different numbers of pumps and operational modes, including pump rotation, have been developed to estimate flow patterns and the resultant sludge mixing. Major solid obstructions including the tank wall, the pump housing, the pump columns, and the 82-in central support column were included in the model. Transient analyses with a two-equation turbulence model were performed with FLUENT{trademark}, a commercial CFD code. All analyses were based on three-dimensional results. Recommended operational guidance was developed assuming that local fluid velocity and characteristic measures of local turbulence could be used as indicators of sludge suspension and spatial mixing. The calculation results show that three pumps, the maximum number of pumps studied, will give acceptable homogeneous mixing in about 6 minutes in terms of flow patterns and turbulent energy dissipation. These qualitative results are consistent with literature results. Sensitivity calculations have also been performed to assess the impact of different operating modes on sludge suspension and mixing. Two-pump operation provides a marginal level of sludge suspension and turbulent mixing, while one pump does not provide acceptable flow patterns and turbulent eddies for good mixing.
Date: April 15, 2008
Creator: Lee, S. & Richard Dimenna, R.
Object Type: Report
System: The UNT Digital Library
Understanding the anomalous dispersion of doubly-ionized carbon plasmas near 47 nm (open access)

Understanding the anomalous dispersion of doubly-ionized carbon plasmas near 47 nm

Over the last several years we have predicted and observed plasmas with an index of refraction greater than one in the soft X-ray regime. These plasmas are usually a few times ionized and have ranged from low-Z carbon plasmas to mid-Z tin plasmas. Our main calculational tool has been the average atom code. We have recently observed C{sup 2+} plasmas with an index of refraction greater than one at a wavelength of 46.9 nm (26.44 eV). In this paper we compare the average atom method, AVATOMKG, against two more detailed methods, OPAL and CAK, for calculating the index of refraction for the carbon plasmas and discuss the different approximations used. We present experimental measurements of carbon plasmas that display this anomalous dispersion phenomenon. It is shown that the average atom calculation is a good approximation when the strongest lines dominate the dispersion. However, when weaker lines make a significant contribution, the more detailed calculations such as OPAL and CAK are essential. During the next decade X-ray free electron lasers and other X-ray sources will be available to probe a wider variety of plasmas at higher densities and shorter wavelengths so understanding the index of refraction in plasmas will be even …
Date: April 15, 2008
Creator: Nilsen, J.; Castor, J. I.; Iglesias, C. A.; Cheng, K. T.; Dunn, J.; Johnson, W. R. et al.
Object Type: Article
System: The UNT Digital Library
Remaining Sites Verification Package for the 100-F-50 Stormwater Runoff Culvert, Waste Site Reclassification Form 2007-001 (open access)

Remaining Sites Verification Package for the 100-F-50 Stormwater Runoff Culvert, Waste Site Reclassification Form 2007-001

The 100-F-50 waste site, part of the 100-FR-2 Operable Unit, is a steel stormwater runoff culvert that runs between two railroad grades in the south-central portion of the 100-F Area. The culvert exiting the west side of the railroad grade is mostly encased in concrete and surrounded by a concrete stormwater collection depression partially filled with soil and vegetation. The drain pipe exiting the east side of the railroad grade embankment is partially filled with soil and rocks. The 100-F-50 stormwater diversion culvert confirmatory sampling results support a reclassification of this site to no action. The current site conditions achieve the remedial action objectives and corresponding remedial action goals established in the Remaining Sites ROD. The results of confirmatory sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River.
Date: April 15, 2008
Creator: Capron, J. M.
Object Type: Report
System: The UNT Digital Library
SRNL POROUS WALL GLASS MICROSPHERES (open access)

SRNL POROUS WALL GLASS MICROSPHERES

The Savannah River National Laboratory (SRNL) has developed a new medium for storage of hydrogen and other gases. This involves fabrication of thin, Porous Walled, Hollow Glass Microspheres (PW-HGMs), with diameters generally in the range of 1 to several hundred microns. What is unique about the glass microballons is that porosity has been induced and controlled within the thin, one micron thick walls, on the scale of 10 to several thousand Angstroms. This porosity results in interesting properties including the ability to use these channels to fill the microballons with special absorbents and other materials, thus providing a contained environment even for reactive species. Gases can now enter the microspheres and be retained on the absorbents, resulting in solid-state and contained storage of even reactive species. Also, the porosity can be altered and controlled in various ways, and even used to filter mixed gas streams within a system. SRNL is involved in about a half dozen different programs involving these PW-HGMs and an overview of some of these activities and results emerging are presented.
Date: April 15, 2008
Creator: Wicks, G; Leung Heung, L & Ray Schumacher, R
Object Type: Article
System: The UNT Digital Library