Sipping fuel and saving lives: increasing fuel economy withoutsacrificing safety (open access)

Sipping fuel and saving lives: increasing fuel economy withoutsacrificing safety

The public, automakers, and policymakers have long worried about trade-offs between increased fuel economy in motor vehicles and reduced safety. The conclusion of a broad group of experts on safety and fuel economy in the auto sector is that no trade-off is required. There are a wide variety of technologies and approaches available to advance vehicle fuel economy that have no effect on vehicle safety. Conversely, there are many technologies and approaches available to advance vehicle safety that are not detrimental to vehicle fuel economy. Congress is considering new policies to increase the fuel economy of new automobiles in order to reduce oil dependence and reduce greenhouse gas emissions. The findings reported here offer reassurance on an important dimension of that work: It is possible to significantly increase the fuel economy of motor vehicles without compromising their safety. Automobiles on the road today demonstrate that higher fuel economy and greater safety can co-exist. Some of the safest vehicles have higher fuel economy, while some of the least safe vehicles driven today--heavy, large trucks and SUVs--have the lowest fuel economy. At an October 3, 2006 workshop, leading researchers from national laboratories, academia, auto manufacturers, insurance research industry, consumer and environmental groups, …
Date: June 11, 2007
Creator: Gordon, Deborah; Greene, David L.; Ross, Marc H. & Wenzel, Tom P.
Object Type: Report
System: The UNT Digital Library
ENERGY EFFICIENCY LIMITS FOR A RECUPERATIVE BAYONET SULFURIC ACID DECOMPOSITION REACTOR FOR SULFUR CYCLE THERMOCHEMICAL HYDROGEN PRODUCTION (open access)

ENERGY EFFICIENCY LIMITS FOR A RECUPERATIVE BAYONET SULFURIC ACID DECOMPOSITION REACTOR FOR SULFUR CYCLE THERMOCHEMICAL HYDROGEN PRODUCTION

A recuperative bayonet reactor design for the high-temperature sulfuric acid decomposition step in sulfur-based thermochemical hydrogen cycles was evaluated using pinch analysis in conjunction with statistical methods. The objective was to establish the minimum energy requirement. Taking hydrogen production via alkaline electrolysis with nuclear power as the benchmark, the acid decomposition step can consume no more than 450 kJ/mol SO{sub 2} for sulfur cycles to be competitive. The lowest value of the minimum heating target, 320.9 kJ/mol SO{sub 2}, was found at the highest pressure (90 bar) and peak process temperature (900 C) considered, and at a feed concentration of 42.5 mol% H{sub 2}SO{sub 4}. This should be low enough for a practical water-splitting process, even including the additional energy required to concentrate the acid feed. Lower temperatures consistently gave higher minimum heating targets. The lowest peak process temperature that could meet the 450-kJ/mol SO{sub 2} benchmark was 750 C. If the decomposition reactor were to be heated indirectly by an advanced gas-cooled reactor heat source (50 C temperature difference between primary and secondary coolants, 25 C minimum temperature difference between the secondary coolant and the process), then sulfur cycles using this concept could be competitive with alkaline electrolysis provided …
Date: June 11, 2009
Creator: Gorensek, M. & Edwards, T.
Object Type: Article
System: The UNT Digital Library
Individual Retirement Accounts (IRAs): Issues and Proposed Expansion (open access)

Individual Retirement Accounts (IRAs): Issues and Proposed Expansion

None
Date: June 11, 2001
Creator: Gravelle, Jane G.
Object Type: Report
System: The UNT Digital Library
War Powers Resolution: Presidential Compliance (open access)

War Powers Resolution: Presidential Compliance

This report gives a summary of the usage of the War Powers Resolution (WPR) and various issues related to proposals to modify or repeal the resolution. The report summarizes most recent developments and background, and gives an overview of United Nations actions, and WPR activities in former Yugoslavia/Bosnia, Kosovo, Iraq (post-1991), Haiti, and Somalia. It also includes commentary on the instances formally reported under the WPR, consultation with Congress, and the current issues which Congress is considering.
Date: June 11, 2008
Creator: Grimmett, Richard F.
Object Type: Report
System: The UNT Digital Library
Simulation of integrated beam experiment designs (open access)

Simulation of integrated beam experiment designs

Simulation of designs of an Integrated Beam Experiment (IBX) class accelerator have been carried out. These simulations are an important tool for validating such designs. Issues such as envelope mismatch and emittance growth can be examined in a self-consistent manner, including the details of injection, accelerator transitions, long-term transport, and longitudinal compression. The simulations are three-dimensional and time-dependent, and begin at the source. They continue up through the end of the acceleration region, at which point the data is passed on to a separate simulation of the drift compression. Results are be presented.
Date: June 11, 2004
Creator: Grote, D. P. & Sharp, W. M.
Object Type: Article
System: The UNT Digital Library
ION SOURCES FOR HIGH AND LOW ENERGY EXTREMES OF ION IMPLANTATION. (open access)

ION SOURCES FOR HIGH AND LOW ENERGY EXTREMES OF ION IMPLANTATION.

None
Date: June 11, 2006
Creator: HERSCHOVITCH, A. & AL., ET
Object Type: Article
System: The UNT Digital Library
Measurement and simulation of the UMERbeam in the sourceregion (open access)

Measurement and simulation of the UMERbeam in the sourceregion

As the beam propagates in the University of Maryland Electron Ring (UMER) complex transverse density structure including halos has been observed. A primary objective of the experiment is to understand the evolution of a space-charge-dominated beam as it propagates over a substantial distance. It is therefore important to understand which details of the beam structure result from propagation of the beam in the ring and which characteristics result from the specific details of the initial distribution. Detailed measurements of the initial beam characteristics have therefore been performed. These include direct measurement of the density using a phosphor screen, as well as pepper pot measurements of the initial transverse distribution function. Detailed measurements of the distribution function have also been obtained by scanning a pinhole aperture across a beam diameter, and recording phosphor screen pictures of the beam downstream of the pinhole. Simulations of the beam characteristics in the gun region have also been performed using the WARP P.I.C. code. From these simulations, the observed behavior has been attributed to a combination of perturbations to the transverse distribution by a cathode grid that is used to modulate the beam current, as well as the complex transverse dynamics that results from the …
Date: June 11, 2004
Creator: Haber, I.; Bernal, S.; Kishek, R. A.; O'Shea, P. G.; Quinn, B.; Reiser, M. et al.
Object Type: Article
System: The UNT Digital Library
Theory of Fine-scale Zonal Flow Generation From Trapped Electron Mode Turbulence (open access)

Theory of Fine-scale Zonal Flow Generation From Trapped Electron Mode Turbulence

Most existing zonal flow generation theory has been developed with a usual assumption of qrρθ¡ << 1 (qr is the radial wave number of zonal flow, and ρθ¡ is the ion poloidal gyrora- dius). However, recent nonlinear gyrokinetic simulations of trapped electron mode (TEM) turbulence exhibit a relatively short radial scale of the zonal flows with qrρθ¡ ~ 1 [Z. Lin et al., IAEA-CN/TH/P2-8 (2006); D. Ernst et al., Phys. Plasmas 16, 055906 (2009)]. This work reports an extension of zonal flow growth calculation to this short wavelength regime via the wave kinetics approach. A generalized expression for the polarization shielding for arbitrary radial wavelength [Lu Wang and T.S. Hahm, to appear in Phys. Plasmas (2009)] which extends the Rosenbluth-Hinton formula in the long wavelength limit is applied.
Date: June 11, 2009
Creator: Hahm, Lu Wang and T.S.
Object Type: Report
System: The UNT Digital Library
Agricultural Export and Food Aid Programs (open access)

Agricultural Export and Food Aid Programs

This report discusses projected agricultural imports and exports for FY2003, as well as legislation that deals with federal programs in support of agricultural exports and federal aid dedicated to farms and agricultural reform.
Date: June 11, 2003
Creator: Hanrahan, Charles E.
Object Type: Report
System: The UNT Digital Library
Vacuum Insulator Studies for the Dielectric Wall Accelerator (open access)

Vacuum Insulator Studies for the Dielectric Wall Accelerator

As part of our ongoing development of the Dielectric Wall Accelerator, we are studying the performance of multilayer high-gradient insulators. These vacuum insulating structures are composed of thin, alternating layers of metal and dielectric, and have been shown to withstand higher gradients than conventional vacuum insulator materials. This paper describes these structures and presents some of our recent results.
Date: June 11, 2007
Creator: Harris, J. R.; Chen, Y. J.; Blackfield, D.; Sanders, D. M.; Caporaso, G. J. & Krogh, M.
Object Type: Article
System: The UNT Digital Library
Rubisco Mechanism: Dissection of the Enolization Partial Reaction. Final Report (open access)

Rubisco Mechanism: Dissection of the Enolization Partial Reaction. Final Report

To test experimentally, the prior theoretical deduction that active-site residue Lys166 of ribulose-bisphosphate carboxylase participates in the carboxylation step of overall catalysis, site-directed mutants and chemically rescued site-directed mutants were characterized by kinetics and product analysis. Although position-166 mutants are able to catalyze normal enolization of ribulose bisphosphate, the enediol intermediate does not undergo carboxylation but rather eliminates phosphate. Furthermore, the chemically rescued mutant (aminoethylation of the severely impaired Lys66Cys mutant) generates a highly active mimic, which displays an enhanced carboxylation/oxygenation partition ratio. These two distinct lines of experimentation document a crucial role of Lys166 in carboxylation and in discrimination between CO{sub 2} and O{sub 2}. To ascertain whether Lys166 functions as an acid or base in facilitation of enolization, the chemically rescued mutant bearing {sup 15}N was titrated by NM R. From pH 6.5-9.5, the amino group of Lys166 remains unprotonated, indicating that it promotes enolization by hydrogen bonding to the ketone group of the substrate.
Date: June 11, 2003
Creator: Hartman, F. C.
Object Type: Report
System: The UNT Digital Library
Benchmarking and Equipment and Controls Assessment for a 'Big Box' Retail Chain (open access)

Benchmarking and Equipment and Controls Assessment for a 'Big Box' Retail Chain

The paper describes work to enable improved energy performance of existing and new retail stores belonging to a national chain and thereby also identify measures and tools that would improve the performance of 'big box' stores generally. A detailed energy simulation model of a standard store design was developed and used to: (1) demonstrate the benefits of benchmarking the energy performance of retail stores of relatively standard design using baselines derived from simulation, (2) identify cost-effective improvements in the efficiency of components to be incorporated in the next design cycle, and (3) use simulation to identify potential control strategy improvements that could be adopted in all stores, improving operational efficiency. The core enabling task of the project was to develop an energy model of the current standard design using the EnergyPlus simulation program. For the purpose of verification of the model against actual utility bills, the model was reconfigured to represent twelve existing stores (seven relatively new stores and five older stores) in different US climates and simulations were performed using weather data obtained from the National Weather Service. The results of this exercise, which showed generally good agreement between predicted and measured total energy use, suggest that dynamic benchmarking …
Date: June 11, 2008
Creator: Haves, Philip; Coffey, Brian & Williams, Scott
Object Type: Article
System: The UNT Digital Library
Information-Gap Robustness for the Test-Analysis Correlation of a Non-Linear Transient Simulation. (open access)

Information-Gap Robustness for the Test-Analysis Correlation of a Non-Linear Transient Simulation.

None
Date: June 11, 2002
Creator: Hemez, Francois M.; Ben-Haim, Yakov & Cogan, Scott
Object Type: Article
System: The UNT Digital Library
Public Transportation Providers’ Obligations Under the Americans with Disabilities Act (ADA) (open access)

Public Transportation Providers’ Obligations Under the Americans with Disabilities Act (ADA)

None
Date: June 11, 2007
Creator: Henning, Anna
Object Type: Report
System: The UNT Digital Library
Science & Technology Review July/August 2004 (open access)

Science & Technology Review July/August 2004

None
Date: June 11, 2004
Creator: Henson, V E
Object Type: Report
System: The UNT Digital Library
Decommissioning the 216-Z-9 Crib Plutonium Mining Facility at the Plutonium Finishing Plant (PFP): Issues Characterization (open access)

Decommissioning the 216-Z-9 Crib Plutonium Mining Facility at the Plutonium Finishing Plant (PFP): Issues Characterization

None
Date: June 11, 2007
Creator: Hopkins, A. M.
Object Type: Article
System: The UNT Digital Library
Mining on Federal Lands (open access)

Mining on Federal Lands

None
Date: June 11, 2002
Creator: Humphries, Marc
Object Type: Report
System: The UNT Digital Library
Development of Novel Electrocatalysts for Proton Exchange Membrane Fuel Cells Annual Report (open access)

Development of Novel Electrocatalysts for Proton Exchange Membrane Fuel Cells Annual Report

The Proton Exchange Membrane Fuel Cell (PEMFC) is one of the most promising power sources for stand-alone utility and electric vehicle applications. Platinum (Pt) Catalyst is used for both fuel and air electrodes in PEMFCs. However, carbon monoxide (CO) contamination of H{sub 2} greatly affects electro catalysts used at the anode of PEMFCs and decreases cell performance. The irreversible poisoning of the anode can occur even in CO concentrations as low as few parts per million (ppm). In this work, we have synthesized several novel elctrocatalysts (Pt/C, Pt/Ru/C, Pt/Mo/C, Pt/Ir and Pt/Ru/Mo) for PEMFCs. These catalysts have been tested for CO tolerance in the H{sub 2}/air fuel cell, using CO concentrations in the H{sub 2} fuel that varies from 10 to 100 ppm. The performance of the electrodes was evaluated by determining the cell potential against current density. The effects of catalyst composition and electrode film preparation method on the performance of PEM fuel cell were also studied. It was found that at 70 C and 3.5 atm pressure at the cathode, Pt-alloy catalyst (10 wt% Pt/Ru/C, 20 wt% Pt/Mo/C) were more CO tolerant than the 20 wt% Pt/C catalyst alone. It was also observed that spraying method was better …
Date: June 11, 2002
Creator: Ilias, Shamsuddin
Object Type: Report
System: The UNT Digital Library
Optical Reflectance Measurements for Commonly Used Reflectors (open access)

Optical Reflectance Measurements for Commonly Used Reflectors

When simulating light collection in scintillators, modeling the angular distribution of optical light reflectance from surfaces is very important. Since light reflectance is poorly understood, either purely specular or purely diffuse reflectance is generally assumed. In this paper we measure the optical reflectance distribution for eleven commonly used reflectors. A 440 nm, output power stabilized, un-polarized laser is shone onto a reflector at a fixed angle of incidence. The reflected light's angular distribution is measured by an array of silicon photodiodes. The photodiodes are movable to cover 2 pi of solid angle. The light-induced current is, through a multiplexer, read out with a digital multimeter. A LabVIEW program controls the motion of the laser and the photodiode array, the multiplexer, and the data collection. The laser can be positioned at any angle with a position accuracy of 10 arc minutes. Each photodiode subtends 6.3o, and the photodiode array can be positioned at any angle with up to 10 arc minute angular resolution. The dynamic range for the current measurements is 105:1. The measured light reflectance distribution was measured to be specular for several ESR films as well as for aluminum foil, mostly diffuse for polytetrafluoroethylene (PTFE) tape and titanium dioxide …
Date: June 11, 2008
Creator: Janecek, Petr Martin & Moses, William
Object Type: Article
System: The UNT Digital Library
Structural Monitoring of a Weapons Test Unit Using Dynamic Signature Analysis (open access)

Structural Monitoring of a Weapons Test Unit Using Dynamic Signature Analysis

A methodology to identify structural changes in weapon systems during environmental test is being developed at Lawrence Livermore National Laboratory. The method is coherence based and relies on comparing the 'dynamic signature' response of the test article before and after an environmental test or test series. Test caused changes in the dynamic signature get mapped to an image matrix where a color scale represents changes in sensor-to-sensor coherence. This methodology is convenient because an image can present large amounts of information in a very compact form and even subtle system changes may be identified. Furthermore, comparison of the dynamic signature response data 'before' and 'after' any test event can be made on a quasi-real time basis. This approach is particularly useful on large and/or complex test articles where many sensors are present and large volumes of data are generated.
Date: June 11, 2004
Creator: Jensen, S.; Malsbury, T.; Leach, R. & Tsap, L.
Object Type: Article
System: The UNT Digital Library
Characterization and Source Term Assessments of Radioactive Particles from Marshall Islands Using Non-Destructive Analytical Techniques (open access)

Characterization and Source Term Assessments of Radioactive Particles from Marshall Islands Using Non-Destructive Analytical Techniques

A considerable fraction of radioactivity entering the environment from different nuclear events is associated with particles. The impact of these events can only be fully assessed where there is some knowledge about the mobility of particle bound radionuclides entering the environment. The behavior of particulate radionuclides is dependent on several factors, including the physical, chemical and redox state of the environment, the characteristics of the particles (e.g., the chemical composition, crystallinity and particle size) and on the oxidative state of radionuclides contained in the particles. Six plutonium-containing particles stemming from Runit Island soil (Marshall Islands) were characterized using non-destructive analytical and microanalytical methods. By determining the activity of {sup 239,240}Pu and {sup 241}Am isotopes from their gamma peaks structural information related to Pu matrix was obtained, and the source term was revealed. Composition and elemental distribution in the particles were studied with synchrotron radiation based micro X-ray fluorescence (SR-{mu}-XRF) spectrometry. Scanning electron microscope equipped with energy dispersive X-ray detector (SEMEDX) and secondary ion mass spectrometer (SIMS) were used to examine particle surfaces. Based on the elemental composition the particles were divided into two groups; particles with plain Pu matrix, and particles where the plutonium is included in Si/O-rich matrix being …
Date: June 11, 2005
Creator: Jernstrom, J; Eriksson, M; Simon, R; Tamborini, G; Bildstein, O; Carlos-Marquez, R et al.
Object Type: Article
System: The UNT Digital Library
Study of Local Reconnection Physics in a Laboratory Plasma (open access)

Study of Local Reconnection Physics in a Laboratory Plasma

A short review of physics results obtained in the Magnetic Reconnection Experiment (MRX) is given with an emphasis on the local features of magnetic reconnection in a controlled environment. Stable two-dimensional current sheets are formed and sustained by induction using two internal coils. The observed reconnection rates are found to be quantitatively consistent with a generalized Sweet-Parker model which incorporates compressibility, unbalanced upstream-downstream pressure, and the effective resistivity. The latter is significantly enhanced over its classical values in the low collisionality regime. Strong local ion heating is measured by an optical probe during the reconnection process, and at least half of the increased ion energy must be due to nonclassical processes, consistent with the resistivity enhancement. Characteristics of high-frequency electrostatic and electromagnetic fluctuations detected in the current sheet suggest presence of the lower-hybrid-drift-like waves with significant magnetic components. The detailed structures of the current sheet are measured and compared with Harris theory and two-fluid theory.
Date: June 11, 2001
Creator: Ji, Hantao; Carter, Troy; Hsu, Scott & Yamada, Masaaki
Object Type: Report
System: The UNT Digital Library
2006 Multiphoton Processes Gordon Conference - June 11-16 (open access)

2006 Multiphoton Processes Gordon Conference - June 11-16

The first Gordon Research Conference on Multiphoton Processes, was held in 1982. The meeting continues to evolve as it embraces both the rapid technological and intellectual growth in the field as well as the multi-disciplinary expertise of the participants. Current areas of interest include: (1) Ionization/Dissociation of Atoms and Molecules in Intense Laser Fields; (2) Frequency Domain Multi-Photon and Multiple-Resonance Spectroscopies of Molecules; (3) Time-Resolved Photoelectron Spectroscopy; (4) Ultrafast Pump-Probe Spectroscopy; (5) Coherent Strong-Field Manipulation of Atoms and Molecules; (6) High-Harmonic Generation; (7) Attosecond Pulse Generation and Measurement; and (8) Super-Intense Laser-Matter Interactions. In developing the program, the conference organizers will strive to blur traditional disciplinary boundaries, involving chemists, physicists, and optical engineers, representing both experiment and theory, as presenters and discussion leaders. The broad range of expertise and different perspectives of attendees should provide a stimulating and unique environment for solving problems and developing new ideas in this rapidly evolving field.
Date: June 11, 2006
Creator: Jones, Robert Rivers
Object Type: Article
System: The UNT Digital Library
Analytical laboratory quality audits (open access)

Analytical laboratory quality audits

Analytical Laboratory Quality Audits are designed to improve laboratory performance. The success of the audit, as for many activities, is based on adequate preparation, precise performance, well documented and insightful reporting, and productive follow-up. Adequate preparation starts with definition of the purpose, scope, and authority for the audit and the primary standards against which the laboratory quality program will be tested. The scope and technical processes involved lead to determining the needed audit team resources. Contact is made with the auditee and a formal audit plan is developed, approved and sent to the auditee laboratory management. Review of the auditee's quality manual, key procedures and historical information during preparation leads to better checklist development and more efficient and effective use of the limited time for data gathering during the audit itself. The audit begins with the opening meeting that sets the stage for the interactions between the audit team and the laboratory staff. Arrangements are worked out for the necessary interviews and examination of processes and records. The information developed during the audit is recorded on the checklists. Laboratory management is kept informed of issues during the audit so there are no surprises at the closing meeting. The audit report …
Date: June 11, 2001
Creator: Kelley, William D.
Object Type: Article
System: The UNT Digital Library