B physics: evidence for the exclusive decay b^+/-_c -> j/psi pi^+ and measurement of the mass of the b^+/-_c meson (open access)

B physics: evidence for the exclusive decay b^+/-_c -> j/psi pi^+ and measurement of the mass of the b^+/-_c meson

We report the first evidence of a fully reconstructed decay mode of the B{sub c}{sup {+-}} meson in the channel B{sub c}{sup {+-}} {yields} J/{psi}{sup {+-}}, with J/{psi} {yields} {mu}{sup +}{mu}{sup -}. The analysis is based on an integrated luminosity of 360 pb{sup -1} in p{bar p} collisions collected by the Collider Detector at Fermilab. We observe 18.9 {+-} 5.7 signal events on a background of 10.0 {+-} 1.4 events and the fit to the J/{psi}{pi}{sup {+-}} mass spectrum yields a B{sub c}{sup {+-}} mass of 6287.0 {+-} 4.8(stat) {+-} 1.1(syst) MeV/c{sup 2}.
Date: May 25, 2005
Creator: Acosta, D.
Object Type: Report
System: The UNT Digital Library
Fabrication and Characterization of Borosilicate Glasses Containing Alpha-Radionuclides and Silver From Conversion and Mixed-Oxide Facilities Proposed for Russia (open access)

Fabrication and Characterization of Borosilicate Glasses Containing Alpha-Radionuclides and Silver From Conversion and Mixed-Oxide Facilities Proposed for Russia

Liquid and solid radioactive wastes are formed during conversion of plutonium metal to oxide and during fabrication of weapons-grade plutonium into mixed-oxide (MOX) fuel. In Russia, these wastes are to be processed for disposition by immobilization in either borosilicate glass or cement matrices depending upon the waste stream-specific radionuclide contents. Vitrification is planned for the liquid high-level waste raffinate stream containing the bulk of the Am-241 produced from Pu-241 decay. Previous work on the Russian MOX Fuel Fabrication Facility (R-MFFF) by the Public Joint Stock Corporation (TVEL) [1] showed that this waste stream may contain significant amounts of silver derived from the electrochemical dissolution of PuO2 using a Ag(II) catalyst. The work reported here further investigated silver solubility limits, which, if exceeded in a production glass melter, allow discrete silver grains to form in the glass and also deposit over time on the bottom of a joule-heated ceramic melter. In melters with immersed electrodes, such as the Russian EP-100 for phosphate glasses or the US Duratek DP-100 type melters for borosilicate glasses that are being considered for use at the Siberian Chemical Combine (SCC) Tomsk site, the undissolved silver could cause a short circuit and an unacceptable production melter failure. …
Date: October 25, 2005
Creator: Aloy, Albert S.; Trofimenko, Alexander V.; Uspensky, Alexander I. & Jardine, Leslie J.
Object Type: Article
System: The UNT Digital Library
Membership of the 109th Congress: A Profile (open access)

Membership of the 109th Congress: A Profile

"This report presents a profile of the membership of the 109th Congress" (p. 1).
Date: October 25, 2005
Creator: Amer, Mildred L.
Object Type: Report
System: The UNT Digital Library
Measurements of the total ion flux from vacuum arc cathodespots (open access)

Measurements of the total ion flux from vacuum arc cathodespots

The ion flux from vacuum arc cathode spots was measured in two vacuum arc systems. The first was a vacuum arc ion source which was modified allowing us to collect ions from arc plasma streaming through an anode mesh. The second discharge system essentially consisted of a cathode placed near the center of a spherically shaped mesh anode. In both systems, the ion current streaming through the mesh was measured by a biased collector. The mesh anodes had geometric transmittances of 60 percent and 72 percent, respectively, which were taken into account as correction factors. The ion current from different cathode materials was measured for 50-500 A of arc current. The ion current normalized by the arc current was found to depend on the cathode material, with values in the range from 5 percent to 19 percent. The normalized ion current is generally greater for elements of low cohesive energy. The ion erosion rates were determined from values of ion current and ion charge states, which were previously measured in the same ion source. The absolute ion erosion rates range from 16-173 mu g/C.
Date: May 25, 2005
Creator: Anders, Andre; Oks, Efim M.; Yushkov, Georgy Yu; Savkin,Konstantin P.; Brown, Ian G. & Nikolaev, Alexey G.
Object Type: Article
System: The UNT Digital Library
Gene expression profiles of Nitrosomonas europaea, an obligate chemolitotroph (open access)

Gene expression profiles of Nitrosomonas europaea, an obligate chemolitotroph

Nitrosomonas europaea is an aerobic lithoautotrophic bacterium that uses ammonia (NH3) as its energy source. As a nitrifier, it is an important participant in the nitrogen cycle, which can also influence the carbon cycle. The focus of this work was to explore the genetic structure and mechanisms underlying the lithoautotrophic growth style of N. europaea. Whole genome gene expression: The gene expression profile of cells in exponential growth and during starvation was analyzed using microarrays. During growth, 98% of the genes increased in expression at least two fold compared to starvation conditions. In growing cells, approximately 30% of the genes were expressed eight fold higher, Approximately 10% were expressed more than 15 fold higher. Approximately 3% (91 genes) were expressed to more than 20 fold of their levels in starved cells. Carbon fixation gene expression: N. europaea fixes carbon via the Calvin-Benson-Bassham (CBB) cycle via a type I ribulose bisphosphate carboxylase/oxygenase (RubisCO). This study showed that transcription of cbb genes was up-regulated when the carbon source was limited, while amo, hao and other energy harvesting related genes were down-regulated. Iron related gene expression: Because N. europaea has a relatively high content of hemes, sufficient Fe must be available in the …
Date: May 25, 2005
Creator: Arp, Daniel J.
Object Type: Report
System: The UNT Digital Library
Coal Bed Methane Primer (open access)

Coal Bed Methane Primer

During the second half of the 1990's Coal Bed Methane (CBM) production increased dramatically nationwide to represent a significant new source of income and natural gas for many independent and established producers. Matching these soaring production rates during this period was a heightened public awareness of environmental concerns. These concerns left unexplained and under-addressed have created a significant growth in public involvement generating literally thousands of unfocused project comments for various regional NEPA efforts resulting in the delayed development of public and fee lands. The accelerating interest in CBM development coupled to the growth in public involvement has prompted the conceptualization of this project for the development of a CBM Primer. The Primer is designed to serve as a summary document, which introduces and encapsulates information pertinent to the development of Coal Bed Methane (CBM), including focused discussions of coal deposits, methane as a natural formed gas, split mineral estates, development techniques, operational issues, producing methods, applicable regulatory frameworks, land and resource management, mitigation measures, preparation of project plans, data availability, Indian Trust issues and relevant environmental technologies. An important aspect of gaining access to federal, state, tribal, or fee lands involves education of a broad array of stakeholders, including …
Date: May 25, 2005
Creator: Arthur, Dan; Langhus, Bruce & Seekins, Jon
Object Type: Report
System: The UNT Digital Library
Beryllium Sampling and Analysis Within the DOE Complex and Opportunities for Standardization (open access)

Beryllium Sampling and Analysis Within the DOE Complex and Opportunities for Standardization

Since the U. S. Department of Energy (DOE) published the DOE Beryllium Rule (10 CFR 850) in 1999, DOE sites have been required to measure beryllium on air filters and wipes for worker protection and for release of materials from beryllium-controlled areas. Measurements in the nanogram range on a filter or wipe are typically required. Industrial hygiene laboratories have applied methods from various analytical compendia, and a number of issues have emerged with sampling and analysis practices. As a result, a committee of analytical chemists, industrial hygienists, and laboratory managers was formed in November 2003 to address the issues. The committee developed a baseline questionnaire and distributed it to DOE sites and other agencies in the U.S. and U.K. The results of the questionnaire are presented in this paper. These results confirmed that a wide variety of practices were in use in the areas of sampling, sample preparation, and analysis. Additionally, although these laboratories are generally accredited by the American Industrial Hygiene Association (AIHA), there are inconsistencies in performance among accredited labs. As a result, there are significant opportunities for development of standard methods that could improve consistency. The current availabilities and needs for standard methods are further discussed in …
Date: January 25, 2005
Creator: BRISSON, MICHAEL
Object Type: Article
System: The UNT Digital Library
Interface reconstruction and sub-zone physics models (open access)

Interface reconstruction and sub-zone physics models

None
Date: August 25, 2005
Creator: Bailey, D S; Brown, S A & Zimmerman, G B
Object Type: Article
System: The UNT Digital Library
Review of The SIAM 100-Digit Challenge: A Study in High-Accuracy Numerical Computing (open access)

Review of The SIAM 100-Digit Challenge: A Study in High-Accuracy Numerical Computing

In the January 2002 edition of SIAM News, Nick Trefethen announced the '$100, 100-Digit Challenge'. In this note he presented ten easy-to-state but hard-to-solve problems of numerical analysis, and challenged readers to find each answer to ten-digit accuracy. Trefethen closed with the enticing comment: 'Hint: They're hard! If anyone gets 50 digits in total, I will be impressed.' This challenge obviously struck a chord in hundreds of numerical mathematicians worldwide, as 94 teams from 25 nations later submitted entries. Many of these submissions exceeded the target of 50 correct digits; in fact, 20 teams achieved a perfect score of 100 correct digits. Trefethen had offered $100 for the best submission. Given the overwhelming response, a generous donor (William Browning, founder of Applied Mathematics, Inc.) provided additional funds to provide a $100 award to each of the 20 winning teams. Soon after the results were out, four participants, each from a winning team, got together and agreed to write a book about the problems and their solutions. The team is truly international: Bornemann is from Germany, Laurie is from South Africa, Wagon is from the USA, and Waldvogel is from Switzerland. This book provides some mathematical background for each problem, and …
Date: January 25, 2005
Creator: Bailey, David
Object Type: Report
System: The UNT Digital Library
[Letter from Members of the Washington Smart Growth Alliance to the BRAC Commission - August 25, 2005] (open access)

[Letter from Members of the Washington Smart Growth Alliance to the BRAC Commission - August 25, 2005]

Letter from the Smart Growth Alliance to the BRAC Commission expressing their concern about the proposed base realignments for the Washington metropolitan area.
Date: August 25, 2005
Creator: Baker, William; Schwartz, Stewart; Peck, Robert; Byrne, Eddie & Black, Sam
Object Type: Letter
System: The UNT Digital Library
Strategic Petroleum Reserve (open access)

Strategic Petroleum Reserve

This report includes information regarding strategic petroleum reserve. Background and analysis, purchases of crude oil, and drawdown of the reserve are among topics discussed in this report.
Date: November 25, 2005
Creator: Bamberger, Robert
Object Type: Report
System: The UNT Digital Library
LCLS X-Ray FEL Output Performance in the Presence of HighlyTime-Dependent Undulator Wakefields (open access)

LCLS X-Ray FEL Output Performance in the Presence of HighlyTime-Dependent Undulator Wakefields

Energy loss due to wakefields within a long undulator, if not compensated by an appropriate tapering of the magnetic field strength, can degrade the FEL process by detuning the resonant FEL frequency. The wakefields arise from the vacuum chamber wall resistivity, its surface roughness, and abrupt changes in its aperture. For LCLS parameters, the resistive-wall component is the most critical and depends upon the chamber material (e.g., Cu) and its radius. Of recent interest[1] is the so-called ''AC'' component of the resistive-wall wake which can lead to strong variations on very short timescales (e.g., {approx} 20 0fs). To study the expected performance of the LCLS in the presence of these wakefields, we have made an extensive series of start-to-end SASE simulations with tracking codes PARMELA and ELEGANT, and time-dependent FEL simulation codes GENESIS1.3 and GINGER. We discuss the impact of the wakefield losses upon output energy, spectral bandwidth, and temporal envelope of the output FEL pulse, as well as the benefits of a partial compensation of the time-dependent wake losses obtained with a slight z-dependent taper in the undulator field. We compare the taper results to those predicted analytically[2].
Date: August 25, 2005
Creator: Bane, Karl L. F.; Emma, Paul; Huang, Heinz-Dieter Nuhn; Stupakov, Gennady; Fawley, William M. & Reiche, Sven
Object Type: Article
System: The UNT Digital Library
Obstacles to Laser Safety (open access)

Obstacles to Laser Safety

The growth of laser development & technology has been remarkable. Unfortunately, a number of traps or obstacles to laser safety have also developed with that growth. The goal of this article is to highlight those traps, in the hope that an aware laser user will avoid them. These traps have been the cause or contributing factor of many a preventable laser accident.
Date: April 25, 2005
Creator: Barat, K.
Object Type: Article
System: The UNT Digital Library
Political Status of Puerto Rico:  Background, Options, and Issues in the 109th Congress (open access)

Political Status of Puerto Rico: Background, Options, and Issues in the 109th Congress

None
Date: May 25, 2005
Creator: Bea, Keith
Object Type: Report
System: The UNT Digital Library
Mad Cow Disease: Agricultural Issues for Congress (open access)

Mad Cow Disease: Agricultural Issues for Congress

This report provides information on how most of the countries banned United States beef after a single report of Bovine Spongiform Encephalopathy (BSE) in a Canadian-born cow after the December 2003 U.S. report. This explains all the steps USDA has taken to reduce the positive cases of BSE by starting special programs. Updated May 25, 2005.
Date: May 25, 2005
Creator: Becker, Geoffrey S.
Object Type: Report
System: The UNT Digital Library
Atomic-Nuclear Coupling Experiments (open access)

Atomic-Nuclear Coupling Experiments

Atomic-nuclear coupling experiments are described, with an emphasis on recent experiments aimed at demonstrating the NEET mechanism in atomic nuclei. Upper limits for x-ray induced decay of the Hf-178 31-y isomer reported by Ahmad and his colleagues are presented, and these upper limits are contrasted with the positive reports of Collins and coworkers.
Date: October 25, 2005
Creator: Becker, J. A.
Object Type: Article
System: The UNT Digital Library
Risks from Worldwide Terrorism: Mortality and Morbidity Patterns and Trends (open access)

Risks from Worldwide Terrorism: Mortality and Morbidity Patterns and Trends

Worldwide data on terrorist incidents between 1968 and 2004 gathered by the RAND corporation and the Oklahoma City National Memorial Institute for the Prevention of Terrorism (MIPT) were assessed for patterns and trends in morbidity/mortality. The data involve a total of 19,828 events, 7,401 ''adverse'' events (each causing {ge}1 victim), 91,346 cases of casualty (either injury or death) and 25,408 deaths. Analyses revealed a number of interesting patterns and apparently significant trends. Most terror-related adverse events, casualties and deaths involved bombs and guns. Weapon-specific patterns and terror-related risk levels in Israel (ISR) have differed markedly from those of all other regions combined (AOR). ISR had a fatal fraction of casualties about half that of AOR, but has experienced relatively constant lifetime terror-related casualty risks on the order of 0.5%--a level 2 to 3 orders of magnitude more than those experienced in AOR, which have increased {approx}100-fold over the same period. Individual event fatality has increased steadily, the median increasing from 14 to 50%. Lorenz curves obtained indicate substantial dispersion among victim/event rates: about half of all victims were caused by the top 2% (10%) of harm-ranked events in OAR (ISR). Extreme values of victim/event rates were found to be well …
Date: January 25, 2005
Creator: Bogen, K. T. & Jones, E. D.
Object Type: Report
System: The UNT Digital Library
Utility Integrated Resource Planning: An Emerging Driver of NewRenewable Generation in the Western United States (open access)

Utility Integrated Resource Planning: An Emerging Driver of NewRenewable Generation in the Western United States

In the United States, markets for renewable generation--especially wind power--have grown substantially in recent years. This growth is typically attributed to technology improvements and resulting cost reductions, the availability of federal tax incentives, and aggressive state policy efforts. But another less widely recognized driver of new renewable generation is poised to play a major role in the coming years: utility integrated resource planning (IRP). Common in the late-1980s to mid-1990s, but relegated to lesser importance as many states took steps to restructure their electricity markets in the late-1990s, IRP has re-emerged in recent years as an important tool for utilities and regulators, particularly in regions such as the western United States, where retail competition has failed to take root. As practiced in the United States, IRP is a formal process by which utilities analyze the costs, benefits, and risks of all resources available to them--both supply- and demand-side--with the ultimate goal of identifying a portfolio of resources that meets their future needs at lowest cost and/or risk. Though the content of any specific utility IRP is unique, all are built on a common basic framework: (1) development of peak demand and load forecasts; (2) assessment of how these forecasts compare …
Date: September 25, 2005
Creator: Bolinger, Mark & Wiser, Ryan
Object Type: Article
System: The UNT Digital Library
Air Force Transformation (open access)

Air Force Transformation

This report considers how the Air Force is changing itself to meet new defensive needs. The issues for Congress on this are mostly budgetary and how effective it will be.
Date: January 25, 2005
Creator: Bolkcom, Christopher
Object Type: Report
System: The UNT Digital Library
Tactical Aircraft Modernization: Issues for Congress (open access)

Tactical Aircraft Modernization: Issues for Congress

None
Date: July 25, 2005
Creator: Bolkcom, Christopher
Object Type: Report
System: The UNT Digital Library
Self-contained Kondo effect in single molecules (open access)

Self-contained Kondo effect in single molecules

Kondo coupling of f and conduction electrons is a common feature of f-electron intermetallics. Similar effects should occur in carbon ring systems (metallocenes). Evidence for Kondo coupling in Ce(C{sub 8}H{sub 8}){sub 2} (cerocene) and the ytterbocene Cp*{sub 2}Yb(bipy) is reported from magnetic susceptibility and L{sub III}-edge x-ray absorption spectroscopy. These well-defined systems provide a new way to study the Kondo effect on the nanoscale, should generate insight into the Anderson Lattice problem, and indicate the importance of this often-ignored contribution to bonding in organometallics.
Date: April 25, 2005
Creator: Booth, Corwin H.; Walter, Marc D.; Daniel, Million; Lukens, WayneW. & Andersen, Richard A.
Object Type: Article
System: The UNT Digital Library
Improved Method for Laser Damage Testing Coated Optics (open access)

Improved Method for Laser Damage Testing Coated Optics

The damage test procedure for qualifying a coating run of anti-reflection coated optics consists of scanning a pulsed 1064 nm laser over a 1 cm x 1 cm area on a test sample to illuminate approximately 2400 sites. Scans are repeated at 3 J/cm{sup 2} increments until the fluence specification for the optic is reached. In the past, initiation of 1 or more damage sites was classified as a failed coating run, requiring the production optics in the corresponding coating lot be reworked and recoated. Recent laser damage growth tests of 300 repetitive pulses performed on numerous damage sites revealed that all were stable up to 20 J/cm{sup 2}. Therefore the acceptance criteria has been modified to allow a moderate number of damage sites, as long as they are smaller than the allowed dig size and are stable (do not grow). Consequently many coating runs that previously would have been rejected are now accepted, resulting in higher yield, lower cost, and improved delivery schedule. The new test also provides assurance that initiated damage sites are stable during long term operation.
Date: October 25, 2005
Creator: Borden, M. R.; Folta, J. A.; Stolz, C. J.; Taylor, J. R.; Wolfe, J. E.; Griffin, A. J. et al.
Object Type: Article
System: The UNT Digital Library
Mitotic Exit Control as an Evolved Complex System (open access)

Mitotic Exit Control as an Evolved Complex System

The exit from mitosis is the last critical decision a cell has to make during a division cycle. A complex regulatory system has evolved to evaluate the success of mitotic events and control this decision. Whereas outstanding genetic work in yeast has led to rapid discovery of a large number of interacting genes involved in the control of mitotic exit, it has also become increasingly difficult to comprehend the logic and mechanistic features embedded in the complex molecular network. Our view is that this difficulty stems in part from the attempt to explain mitotic exit control using concepts from traditional top-down engineering design, and that exciting new results from evolutionary engineering design applied to networks and electronic circuits may lend better insights. We focus on four particularly intriguing features of the mitotic exit control system: the two-stepped release of Cdc14; the self-activating nature of Tem1 GTPase; the spatial sensor associated with the spindle pole body; and the extensive redundancy in the mitotic exit network. We attempt to examine these design features from the perspective of evolutionary design and complex system engineering.
Date: April 25, 2005
Creator: Bosl, W & Li, R
Object Type: Article
System: The UNT Digital Library