Historical Sulfur Dioxide Emissions 1850-2000: Methods and Results (open access)

Historical Sulfur Dioxide Emissions 1850-2000: Methods and Results

A global, self-consistent estimate of sulfur dioxide emissions over the last one and a half century were estimated by using a combination of bottom-up and best available inventory methods including all anthropogenic sources. We find that global sulfur dioxide emissions peaked about 1980 and have generally declined since this time. Emissions were extrapolated to a 1{sup o} x 1{sup o} grid for the time period 1850-2000 at annual resolution with two emission height levels and by season. Emissions are somewhat higher in the recent past in this new work as compared with some comprehensive estimates. This difference is largely due to our use of emissions factors that vary with time to account for sulfur removals from fossil fuels and industrial smelting processes.
Date: January 25, 2004
Creator: Smith, Steven J.; Andres, Robert; Conception , Elvira & Lurz, Joshua
Object Type: Report
System: The UNT Digital Library
Border Security: Improvements Needed to Reduce Time Taken to Adjudicate Visas for Science Students and Scholars (open access)

Border Security: Improvements Needed to Reduce Time Taken to Adjudicate Visas for Science Students and Scholars

A letter report issued by the General Accounting Office with an abstract that begins "Each year thousands of international science students and scholars apply for visas to enter the United States to participate in education and exchange programs. They offer our country diversity and intellectual knowledge and are an economic resource. At the same time, the United States has important national security interests in screening these individuals when they apply for a visa. At a hearing held by the House Committee on Science on March 26, 2003, witnesses raised concern about the length of time it takes for science students and scholars to obtain a visa and about losing top international students to other countries due to delays in the visa process. GAO reviewed 1) how long it takes a science student or scholar from another country to obtain a visa and the factors contributing to the length of time, and 2) what measures are under way to improve the process and decrease the number of pending cases."
Date: February 25, 2004
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library
Border Security: Improvements Needed to Reduce Time Taken to Adjudicate Visas for Science Students and Scholars (open access)

Border Security: Improvements Needed to Reduce Time Taken to Adjudicate Visas for Science Students and Scholars

Testimony issued by the General Accounting Office with an abstract that begins "Each year thousands of international science students and scholars apply for visas to enter the United States to participate in education and exchange programs. They offer our country diversity and intellectual knowledge and are an economic resource. At the same time, the United States has important national security interests in screening these individuals when they apply for a visa. At a House Committee on Science hearing in March 2003, witnesses raised concern about the length of time it takes for science students and scholars to obtain a visa and about losing top international students to other countries due to visa delays. GAO reviewed 1) how long it takes a science student or scholar from another country to obtain a visa and the factors contributing to the length of time, and 2) what measures are under way to improve the process and decrease the number of pending cases."
Date: February 25, 2004
Creator: United States. General Accounting Office.
Object Type: Text
System: The UNT Digital Library
The CDF Run IIb Silicon Detector (open access)

The CDF Run IIb Silicon Detector

Fermilab plans to deliver 5-15 fb{sup -1} of integrated luminosity to the CDF and D0 experiments. The current inner silicon detectors at CDF (SVXIIa and L00) will not tolerate the radiation dose associated with high luminosity running and will need to be replaced. A new readout chip (SVX4) has been designed in radiation-hard 0.25 {micro}m CMOS technology. Single sided sensors are arranged in a compact structure, called a stave, with integrated readout and cooling systems. This paper describes the general design of the Run IIb system, testing results of prototype electrical components (staves), and prototype silicon sensor performance before and after irradiation.
Date: February 25, 2004
Creator: Aoki, M.; Bacchetta, N. & al., S. Behari et
Object Type: Article
System: The UNT Digital Library
Direct observation of the saturation of stimulated Brillouin scattering by ion-trapping induced frequency shifts (open access)

Direct observation of the saturation of stimulated Brillouin scattering by ion-trapping induced frequency shifts

We report the first measurement of the saturation of stimulated Brillouin scattering (SBS) by an ion-trapping induced frequency shift, which was achieved by directly measuring the amplitude and absolute frequency of SBS-driven ion-acoustic waves (IAW). A frequency shift of up to 30% and a simultaneous saturation of driven IAW and SBS reflectivity was observed. The scaling of the frequency shift with the IAW amplitude compares well with theoretical calculations. We have further measured fast 30 ps oscillations of the SBS-driven IAW amplitude induced by the frequency shift.
Date: February 25, 2004
Creator: Niemann, C.; Price, D.; Meezan, N.; Gregori, G.; Divol, L.; Froula, D. H. et al.
Object Type: Article
System: The UNT Digital Library
Handling the Handbag Diagram in Compton Scattering on the Proton (open access)

Handling the Handbag Diagram in Compton Scattering on the Proton

Poincare invariance, gauge invariance, conservation of parity and time reversal invariance are respected in an impulse approximation evaluation of the handbag diagram. Proton wave functions, previously constrained by comparison with measured form factors, that incorporate the influence of quark transverse and orbital angular momentum (and the corresponding violation of proton helicity conservation) are used. Computed cross sections are found to be in reasonably good agreement with early measurements. The helicity correlation between the incident photon and outgoing proton, K{sub LL}, is both large and positive at back angles. For photon laboratory energies of {le} 6 GeV, we find that K{sub LL} {ne} A{sub LL}, D{sub LL} {ne} 1, and that the polarization P can be large.
Date: February 25, 2004
Creator: Miller, Gerald A.
Object Type: Article
System: The UNT Digital Library
Human Capital: Preliminary Observations on Proposed DHS Human Capital Regulations (open access)

Human Capital: Preliminary Observations on Proposed DHS Human Capital Regulations

Testimony issued by the General Accounting Office with an abstract that begins "The creation of the Department of Homeland Security (DHS) almost one year ago represents an historic moment for the federal government to fundamentally transform how the nation will protect itself from terrorism. DHS is continuing to transform and integrate a disparate group of agencies with multiple missions, values, and cultures into a strong and effective cabinet department. Together with this unique opportunity, however, also comes significant risk to the nation that could occur if this transformation is not implemented successfully. In fact, GAO designated this implementation and transformation as high risk in January 2003. Congress provided DHS with significant flexibility to design a modern human capital management system. GAO reported in September 2003 that the design effort to develop the system was collaborative and consistent with positive elements of transformation. Last Friday, the Secretary of DHS and the Director of the Office of Personnel Management (OPM) released for public comment draft regulations for DHS's new human capital system. This testimony provides preliminary observations on selected major provisions of the proposed system."
Date: February 25, 2004
Creator: United States. General Accounting Office.
Object Type: Text
System: The UNT Digital Library
India-U.S. Economic Relations (open access)

India-U.S. Economic Relations

This report discusses India's economic relationship with the United States. Discussing issues that relate to trade, poverty, and other subsequent challenges that would be faced in efforts to reform India's economy.
Date: February 25, 2004
Creator: Morrison, Wayne M. & Kronstadt, K. Alan
Object Type: Report
System: The UNT Digital Library
India-U.S. Relations (open access)

India-U.S. Relations

This report discusses the context of India- U.S. relations, and its bilateral issues.
Date: February 25, 2004
Creator: Kronstadt, K. Alan
Object Type: Report
System: The UNT Digital Library
Individual Fishing Quotas: Economic Effects on Processors and Methods Available to Protect Communities (open access)

Individual Fishing Quotas: Economic Effects on Processors and Methods Available to Protect Communities

Testimony issued by the General Accounting Office with an abstract that begins "To address overfishing, the National Marine Fisheries Service started using individual fishing quotas (IFQ) as a fishery conservation and management tool in 1990. Under an IFQ program, a regional fishery management council sets a maximum, or total allowable catch, and allocates the privilege to harvest a certain portion of the catch in the form of quota to individual vessels, fishermen, or other eligible recipients. IFQ programs have achieved many of the desired conservation and management benefits, such as helping to stabilize fisheries, reducing excessive investment in fishing capacity, and improving safety. However, concerns have been raised about the economic effects of IFQ programs on fish processors and fishing communities, among others. This testimony is based on two GAO reports on issues related to the use of IFQs (Individual Fishing Quotas: Better Information Could Improve Program Management, GAO-03- 159, Dec. 11, 2002, and Individual Fishing Quotas: Methods for Community Protection and New Entry Require Periodic Evaluation, GAO-04-277, Feb. 24, 2004). Specifically, GAO addressed the (1) economic effects of the Alaskan halibut IFQ program on processors and (2) the methods available for protecting communities under an IFQ program."
Date: February 25, 2004
Creator: United States. General Accounting Office.
Object Type: Text
System: The UNT Digital Library
INTEGRATED GEOLOGIC-ENGINEERING MODEL FOR REEF AND CARBONATE SHOAL RESERVOIRS ASSOCIATED WITH PALEOHIGHS: UPPER JURASSIC SMACKOVER FORMATION, NORTHEASTERN GULF OF MEXICO (open access)

INTEGRATED GEOLOGIC-ENGINEERING MODEL FOR REEF AND CARBONATE SHOAL RESERVOIRS ASSOCIATED WITH PALEOHIGHS: UPPER JURASSIC SMACKOVER FORMATION, NORTHEASTERN GULF OF MEXICO

The University of Alabama, in cooperation with Texas A&M University, McGill University, Longleaf Energy Group, Strago Petroleum Corporation, and Paramount Petroleum Company, has undertaken an integrated, interdisciplinary geoscientific and engineering research project. The project is designed to characterize and model reservoir architecture, pore systems and rock-fluid interactions at the pore to field scale in Upper Jurassic Smackover reef and carbonate shoal reservoirs associated with varying degrees of relief on pre-Mesozoic basement paleohighs in the northeastern Gulf of Mexico. The project effort includes the prediction of fluid flow in carbonate reservoirs through reservoir simulation modeling which utilizes geologic reservoir characterization and modeling and the prediction of carbonate reservoir architecture, heterogeneity and quality through seismic imaging. The primary goal of the project is to increase the profitability, producibility and efficiency of recovery of oil from existing and undiscovered Upper Jurassic fields characterized by reef and carbonate shoals associated with pre-Mesozoic basement paleohighs. Geoscientific reservoir property, geophysical seismic attribute, petrophysical property, and engineering property characterization has shown that reef (thrombolite) and shoal reservoir lithofacies developed on the flanks of high-relief crystalline basement paleohighs (Vocation Field example) and on the crest and flanks of low-relief crystalline basement paleohighs (Appleton Field example). The reef thrombolite …
Date: February 25, 2004
Creator: Mancini, Ernest A.
Object Type: Report
System: The UNT Digital Library
Isentropic Compression Loading of HMX and the Pressure-induced Phase Transition at 27 GPa (open access)

Isentropic Compression Loading of HMX and the Pressure-induced Phase Transition at 27 GPa

The 27 GPa pressure-induced epsilon-phi phase transition in HMX is explored using the Isentropic Compression Experiment (ICE) technique at the Sandia National Laboratories Z-machine facility. Our data indicate that this phase transition is sluggish and if it does occur to any extent under the time scales (200-500 ns) and strain rates (5 x 10{sup 5}) typical of ICE loading conditions, the amount of conversion is small.
Date: February 25, 2004
Creator: Hare, D E; Reisman, D B; Dick, J J & Forbes, J W
Object Type: Article
System: The UNT Digital Library
Population genetic variation in gene expression is associated withphenotypic variation in Saccharomyces cerevisiae (open access)

Population genetic variation in gene expression is associated withphenotypic variation in Saccharomyces cerevisiae

The relationship between genetic variation in gene expression and phenotypic variation observable in nature is not well understood. Identifying how many phenotypes are associated with differences in gene expression and how many gene-expression differences are associated with a phenotype is important to understanding the molecular basis and evolution of complex traits. Results: We compared levels of gene expression among nine natural isolates of Saccharomyces cerevisiae grown either in the presence or absence of copper sulfate. Of the nine strains, two show a reduced growth rate and two others are rust colored in the presence of copper sulfate. We identified 633 genes that show significant differences in expression among strains. Of these genes,20 were correlated with resistance to copper sulfate and 24 were correlated with rust coloration. The function of these genes in combination with their expression pattern suggests the presence of both correlative and causative expression differences. But the majority of differentially expressed genes were not correlated with either phenotype and showed the same expression pattern both in the presence and absence of copper sulfate. To determine whether these expression differences may contribute to phenotypic variation under other environmental conditions, we examined one phenotype, freeze tolerance, predicted by the differential …
Date: February 25, 2004
Creator: Fay, Justin C.; McCullough, Heather L.; Sniegowski, Paul D. & Eisen, Michael B.
Object Type: Article
System: The UNT Digital Library
Recent physics results from CDF and D0 (open access)

Recent physics results from CDF and D0

Recent physics results from CDF and D0 on heavy flavor physics, electroweak precision measurements, top physics, QCD and searches for new physics are discussed. The results are based on approximately 140 pb{sup -1} of data collected at {radical}s = 1.96 TeV between 2002 and 2003.
Date: February 25, 2004
Creator: Thomson, Evelyn
Object Type: Article
System: The UNT Digital Library
The Safe and Drug-Free Schools and Communities Program: Background and Context (open access)

The Safe and Drug-Free Schools and Communities Program: Background and Context

This reports details the effect the Safe and and Drug-Free Schools and Communities Program including the change in violence and drug use.
Date: February 25, 2004
Creator: Cooper, Edith Fairman
Object Type: Report
System: The UNT Digital Library
The Tax Deduction for Classroom Expenses of Elementary and Secondary School Teachers (open access)

The Tax Deduction for Classroom Expenses of Elementary and Secondary School Teachers

This report describes the classroom expense deduction, its interaction with other tax provisions, and proposals made concerning the tax benefit during the 108th Congress.
Date: February 25, 2004
Creator: Levine, Linda
Object Type: Report
System: The UNT Digital Library
XRCC3 ATPase activity is required for normal XRCC3-Rad51C complex dynamics and homologous recombination (open access)

XRCC3 ATPase activity is required for normal XRCC3-Rad51C complex dynamics and homologous recombination

Homologous recombinational repair is a major DNA repair pathway that preserves chromosomal integrity by removing double-strand breaks, crosslinks, and other DNA damage. In eukaryotic cells, the Rad51 paralogs (XRCC2, XRCC3, Rad51B, Rad51C, and Rad51D) are involved in this process, although their exact functions are largely undetermined. All five paralogs contain ATPase motifs, and XRCC3 appears to exist in a single complex with Rad51C. To begin to examine the function of this Rad51C-XRCC3 complex, we generated mammalian expression vectors that produce human wild-type XRCC3 or mutant XRCC3 with either a non-conservative mutation (K113A) or a conservative mutation (K113R) in the GKT Walker A box of the ATPase motif. The three vectors were independently transfected into Xrcc3-deficient irs1SF CHO cells. Wild-type XRCC3 complemented irs1SF cells, albeit to varying degrees, while ATPase mutants had no complementing activity, even when the mutant protein was expressed at comparable levels to that in wild-type-complemented clones. Because of the mutants' dysfunction, we propose that ATP binding and hydrolyzing activities of XRCC3 are essential. We tested in vitro complex formation by wild-type and mutant XRCC3 with His6-tagged Rad51C upon coexpression in bacteria, nickel affinity purification, and western blotting. Wild-type and K113A mutant XRCC3 formed stable complexes with Rad51C …
Date: February 25, 2004
Creator: Yamada, N; Hinz, J; Kopf, V L; Segalle, K & Thompson, L
Object Type: Article
System: The UNT Digital Library
Afghanistan: Post-War Governance, Security, and U.S. Policy (open access)

Afghanistan: Post-War Governance, Security, and U.S. Policy

The United States and its allies are helping Afghanistan emerging from more than 22 years of warfare, although substantial risk to Afghan stability remains. Before the U.S. military campaign against the orthodox Islamist Taliban movement began on October 7, 2001, Afghanistan had been mired in conflict since the Soviet invasion of Afghanistan in 1979. The defeat of the Taliban has enabled the United States and its coalition partners to send forces throughout Afghanistan to search for Taliban and Al Qaeda fighters and leaders that remain at large, including Osama bin Laden. As the war against remaining Al Qaeda and Taliban elements winds down, the United States is shifting its military focus toward stabilizing the interim government, including training a new Afghan national army, and supporting the international security force (ISAF) that is helping the new government provide security.
Date: March 25, 2004
Creator: Katzman, Kenneth
Object Type: Report
System: The UNT Digital Library
Boron-Carbide Barrier Layers in Scandium-Silicon Multilayers (open access)

Boron-Carbide Barrier Layers in Scandium-Silicon Multilayers

None
Date: March 25, 2004
Creator: Jankowski, Alan Frederic; Saw, Cheng K.; Walton, Christopher C.; Hayes, Jeffrey P. & Nilsen, Joseph
Object Type: Article
System: The UNT Digital Library
Characterization of Vapor Deposited Nano Structured Membranes (open access)

Characterization of Vapor Deposited Nano Structured Membranes

The vapor deposition methods of planar magnetron sputtering and electron-beam evaporation are used to synthesize materials with nano structured morphological features that have ultra-high surface areas with continuous open porosity at the nano scale. These nano structured membranes are used in a variety of fuel cells to provide electrode and catalytic functions. Specifically, stand alone and composite nickel electrodes for use in thin film solid-oxide, and molten carbonate fuel cells are formed by sputter deposition and electron bean evaporation, respectively. Also, a potentially high-performance catalyst material for the direct reformation of hydrocarbon fuels at low temperatures is deposited as a nano structure by the reactive sputtering of a copper-zinc alloy using a partial pressure of oxygen at an elevated substrate temperature.
Date: March 25, 2004
Creator: Jankowski, Alan Frederic; Cherepy, Nerine J.; Ferreira, James L. & Hayes, Jeffrey P.
Object Type: Article
System: The UNT Digital Library
Development of a functionalized Xenon biosensor (open access)

Development of a functionalized Xenon biosensor

NMR-based biosensors that utilize laser-polarized xenon offer potential advantages beyond current sensing technologies. These advantages include the capacity to simultaneously detect multiple analytes, the applicability to in vivo spectroscopy and imaging, and the possibility of remote amplified detection. Here we present a detailed NMR characterization of the binding of a biotin-derivatized caged-xenon sensor to avidin. Binding of functionalized xenon to avidin leads to a change in the chemical shift of the encapsulated xenon in addition to a broadening of the resonance, both of which serve as NMR markers of ligand-target interaction. A control experiment in which the biotin-binding site of avidin was blocked with native biotin showed no such spectral changes, confirming that only specific binding, rather than nonspecific contact, between avidin and functionalized xenon leads to the effects on the xenon NMR spectrum. The exchange rate of xenon (between solution and cage) and the xenon spin-lattice relaxation rate were not changed significantly upon binding. We describe two methods for enhancing the signal from functionalized xenon by exploiting the laser-polarized xenon magnetization reservoir. We also show that the xenon chemical shifts are distinct for xenon encapsulated in different diastereomeric cage molecules. This demonstrates the potential for tuning the encapsulated xenon …
Date: March 25, 2004
Creator: Spence, Megan M.; Ruiz, E. Janette; Rubin, Seth M.; Lowery, Thomas J.; Winssinger, Nicolas; Schultz, Peter G. et al.
Object Type: Article
System: The UNT Digital Library
DEVELOPMENT OF A HYDRONIC ROOFTOP UNIT -- HYPAK (open access)

DEVELOPMENT OF A HYDRONIC ROOFTOP UNIT -- HYPAK

The majority of US commercial floor space is cooled by rooftop HVAC units (RTU's). RTU popularity derives chiefly from their low initial cost and relative ease of service access without disturbing building occupants. Unfortunately, current RTU's are inherently inefficient due to a combination of characteristics that unnecessarily increase cooling loads and energy use. Existing RTU's in the U.S. consume an estimated 2.4 quads annually. Inefficient RTU's create an estimated 3.5% of U.S. CO{sub 2} emissions, thus contributing significantly to global warming. Also, RTU's often fail to maintain adequate ventilation air and air filtration. This project was developed to evaluate the feasibility of a radically new ''HyPak'' RTU design that significantly and cost-effectively increases RTU performance and delivered air quality. The objective of the HyPak Project was to design, develop and test a hydronic RTU that provides a quantum improvement over conventional RTU performance. Our proposal targeted 60% and 50% reduction in electrical energy use by the HyPak RTU for dry and humid climates, respectively, when compared with a conventional unit.
Date: March 25, 2004
Creator: Lee, Eric; Bourne, Dick & Berman, Mark
Object Type: Report
System: The UNT Digital Library
Energy management in cleanrooms: From the lab to themarketplace (open access)

Energy management in cleanrooms: From the lab to themarketplace

Lawrence Berkeley Laboratory is working to improve energy efficiency in high-tech facilities, i.e., laboratories, data centers, and clean rooms. With their high ventilation requirements and correspondingly high process loads, 7x24 operation, and importance to the overall economy, these types of facilities offer important (and often under-exploited) potential for energy savings. In California alone, two large electric power plants could be avoided with the widespread adoption of measures to improve energy efficiency in this arena, saving half a billion dollars per year for facility owners. To help identify specific promising opportunities, the California Energy Commission sponsored the development of technology research ''Roadmaps'' for clean rooms and laboratories (in 2002) and data centers (in 2003). These were developed with industry participation and provided dozens of specific recommendations. The balance of this article focuses on the case of clean rooms.
Date: March 25, 2004
Creator: Mills, Evan
Object Type: Article
System: The UNT Digital Library
Federal Farm Promotion (“Check-Off”) Programs (open access)

Federal Farm Promotion (“Check-Off”) Programs

None
Date: March 25, 2004
Creator: Becker, Geoffrey S.
Object Type: Report
System: The UNT Digital Library