Simulation of a Production Facility with an Automated Transport System (open access)

Simulation of a Production Facility with an Automated Transport System

A model was needed to assess material throughput and validate the conceptual design of a production facility, including equipment lists and layout. The initial desire was to use a commercially available discrete event simulation package. However, the available software was found to be too limited in capability. Database interface software was used to develop autonomous intelligent manufacturing workstations and material transporters. The initial Extend model used to assess material throughput and develop equipment lists for the preconceptual design effort was upgraded with software add-ons from Simulation Dynamics, Inc. (SDI). Use of the SDI database interface allowed the upgraded model to include: 1. a material mass balance at any level of detail required by the user, and 2. a transport system model that includes all transport system movements, time delays, and transfers between systems. This model will assist in evaluating transport system capacity, sensitive time delays in the system, and optimal operating strategies. An additional benefit of using the SDI database interface is dramatically improved run time performance. This allows significantly more runs to be completed to provide better statistics for overall plant performance. The model has all system and process parameters entered into sub-component accessible tables. All information for the …
Date: April 7, 2004
Creator: ABRAMCZYK, GLENN
Object Type: Report
System: The UNT Digital Library
Early Fermi Gamma-ray Space Telescope Observations of the Quasar 3C454.3 (open access)

Early Fermi Gamma-ray Space Telescope Observations of the Quasar 3C454.3

This is the first report of Fermi Gamma-ray Space Telescope observations of the quasar 3C 454.3, which has been undergoing pronounced long-term outbursts since 2000. The data from the Large Area Telescope (LAT), covering 2008 July 7-October 6, indicate strong, highly variable {gamma}-ray emission with an average flux of {approx} 3 x 10{sup -6} photons cm{sup -2} s{sup -1}, for energies > 100 MeV. The {gamma}-ray flux is variable, with strong, distinct, symmetrically-shaped flares for which the flux increases by a factor of several on a time scale of about three days. This variability indicates a compact emission region, and the requirement that the source is optically thin to pair-production implies relativistic beaming with Doppler factor {delta} > 8, consistent with the values inferred from VLBI observations of superluminal expansion ({delta} {approx} 25). The observed {gamma}-ray spectrum is not consistent with a simple power-law, but instead steepens strongly above {approx} 2 GeV, and is well described by a broken power-law with photon indices of {approx} 2.3 and {approx} 3.5 below and above the break, respectively. This is the first direct observation of a break in the spectrum of a high luminosity blazar above 100 MeV, and it is likely direct …
Date: May 7, 2009
Creator: Abdo, A. A.
Object Type: Article
System: The UNT Digital Library
Electric Reliability: Options for Electric Transmission Infrastructure Improvements (open access)

Electric Reliability: Options for Electric Transmission Infrastructure Improvements

None
Date: June 7, 2005
Creator: Abel, Amy
Object Type: Report
System: The UNT Digital Library
Electric Utility Provisions in House-Passed H.R. 6, 109th Congress (open access)

Electric Utility Provisions in House-Passed H.R. 6, 109th Congress

None
Date: June 7, 2005
Creator: Abel, Amy
Object Type: Report
System: The UNT Digital Library
Electricity: The Road Toward Restructuring (open access)

Electricity: The Road Toward Restructuring

The Public Utility Holding Company Act of 1935 (PUHCA) and the Federal Power Act (FPA) were enacted to eliminate unfair practices and other abuses by electricity and gas holding companies by requiring federal control and regulation of interstate public utility holding companies. Comprehensive energy legislation has passed the House and Senate. The House passed H.R. 6 on April 11, 2003. On July 31, 2003, the Senate suspended debate on S. 14, inserted the text of H.R. 4 (107th Congress) as a substitute, and passed H.R. 6. A conference agreement was reached November 17, 2003, and passed by the House the next day. H.R. 6 includes an electricity title that would, in part, repeal PUHCA, would prospectively repeal the mandatory purchase requirement under PURPA, and would create an electric reliability organization. On June 15, 2004, H.R. 4503, a comprehensive energy policy bill, passed the House.
Date: September 7, 2001
Creator: Abel, Amy & Parker, Larry
Object Type: Report
System: The UNT Digital Library
The H II Region of a Primordial Star (open access)

The H II Region of a Primordial Star

The concordance model of cosmology and structure formation predicts the formation of isolated very massive stars at high redshifts in dark matter dominated halos of 10{sup 5} to 10{sup 6} Msun. These stars photo-ionize their host primordial molecular clouds, expelling all the baryons from their halos. When the stars die, a relic H II region is formed within which large amounts of molecular hydrogen form which will allow the gas to cool efficiently when gravity assembles it into larger dark matter halos. The filaments surrounding the first star hosting halo are largely shielded and provide the pathway for gas to stream into the halo when the star has died. We present the first fully three dimensional cosmological radiation hydrodynamical simulations that follow all these effects. A novel adaptive ray casting technique incorporates the time dependent radiative transfer around point sources. This approach is fast enough so that radiation transport, kinetic rate equations, and hydrodynamics are solved self-consistently. It retains the time derivative of the transfer equation and is explicitly photon conserving. This method is integrated with the cosmological adaptive mesh refinement code enzo, and runs on distributed and shared memory parallel architectures. Where applicable the three dimensional calculation not only …
Date: June 7, 2006
Creator: Abel, Tom; Wise, John H.; /KIPAC, Menlo Park; Bryan, Greg L. & /Columbia U., Astron. Astrophys.
Object Type: Report
System: The UNT Digital Library
Measurement of HOMs in the RHIC RF Cavities (open access)

Measurement of HOMs in the RHIC RF Cavities

The authors present results of Higher Order Modes (HOMs) measurements in the RHIC accelerating (28 MHz system) and storage (197 MHz system) cavities. The power of the excited HOMs deposited into the HOM damper is measured and compared with an analytical calculation of the HOMs power. The quality factors (Q) are also measured and compared to previous measurements.
Date: January 7, 2009
Creator: Abreu,N.P. & Choi, E. M.
Object Type: Report
System: The UNT Digital Library
Top physics: measurement of the tt-bar production cross section in p anti-p collisions at s**(1/2) = 1.96 tev using lepton + jets events with secondary vertex b-tagging (open access)

Top physics: measurement of the tt-bar production cross section in p anti-p collisions at s**(1/2) = 1.96 tev using lepton + jets events with secondary vertex b-tagging

We present a measurement of the t{bar t} production cross section using events with one charged lepton and jets from p{bar p} collisions at a center-of-mass energy of 1.96TeV. In these events, heavy flavor quarks from top quark decay are identified with a secondary vertex tagging algorithm. From 162 pb{sup -1} of data collected by the Collider Detector at Fermilab, a total of 48 candidate events are selected, where 13.5 {+-} 1.8 events are expected from background contributions. We measure a t{bar t} production cross section of 5.6{sub -1.1}{sup _1.2}(stat.){sub -0.6}{sup +0.9}(syst.)pb.
Date: April 7, 2005
Creator: Acosta, D.
Object Type: Report
System: The UNT Digital Library
The Rheology of Concentrated Suspensions (open access)

The Rheology of Concentrated Suspensions

Research program on the rheological properties of flowing suspensions. The primary purpose of the research supported by this grant was to study the flow characteristics of concentrated suspensions of non-colloidal solid particles and thereby construct a comprehensive and robust theoretical framework for modeling such systems quantitatively. At first glance, this seemed like a modest goal, not difficult to achieve, given that such suspensions were viewed simply as Newtonian fluids with an effective viscosity equal to the product of the viscosity of the suspending fluid times a function of the particle volume fraction. But thanks to the research findings of the Principal Investigator and of his Associates, made possible by the steady and continuous support which the PI received from the DOE Office of Basic Energy Sciences, the subject is now seen to be more complicated and therefore much more interesting in that concentrated suspensions have been shown to exhibit fascinating and unique rheological properties of their own that have no counterpart in flowing Newtonian or even non-Newtonian (polymeric) fluids. In fact, it is generally acknowledged that, as the result of these investigations for which the PI received the 2001 National Medal of Science, our understanding of how suspensions behave under …
Date: September 7, 2004
Creator: Acrivos, Andreas
Object Type: Report
System: The UNT Digital Library
Type 1 Frequency Doubling at 1064 nm in LaCa40(B03)3 (LaCOB), GdCa40(B03)3(GdCOB), and YCa40(B03)3(YCOB) (open access)

Type 1 Frequency Doubling at 1064 nm in LaCa40(B03)3 (LaCOB), GdCa40(B03)3(GdCOB), and YCa40(B03)3(YCOB)

We have grown and characterized LaCOB, a new member to the GdCOB family of nonlinear crystals. LaCOB has a d{sub eff} of 0.52 {plus_minus} 0.05 pm/V and an angular sensitivity of 1224 {plus_minus} 184 (cm-rad){sup -1} for type I frequency doubling at 1064 nm. The d{sub {alpha}{beta}{beta}} and d{sub {gamma}{beta}{beta}} coefficients of the nonlinear optical tensor for LaCOB, GdCOB, and YCOB were determined to have values of {vert_bar}0.26 {plus_minus} 0.04{vert_bar} pm/V and |1.69 {plus_minus} 0.17| pm/V, respectively. Results of phase-matching angle measurements at 1064 nm and 1047 nm predict LaCOB to be non-critically phase-matched (NCPM) at 1042 {plus_minus} 1.5 nm. We also estimate the thermal sensitivity of LaCOB to be less than 0.1 (cm- C){sup -1}.
Date: March 7, 2001
Creator: Adams, J. J.; Ebbers, C. A.; Schaffers, K. I. & Payne, S. A.
Object Type: Article
System: The UNT Digital Library
Production of e+e- Pairs Accompanied by Nuclear Dissociation in Ultra-peripheral Heavy Ion Collisions (open access)

Production of e+e- Pairs Accompanied by Nuclear Dissociation in Ultra-peripheral Heavy Ion Collisions

We present the first data on e{sup +}e{sup -} pair production accompanied by nuclear breakup in ultra-peripheral gold-gold collisions at a center of mass energy of 200 GeV per nucleon pair. The nuclear breakup requirement selects events at small impact parameters, where higher-order corrections to the pair production cross section should be enhanced. We compare the pair kinematic distributions with two calculations: one based on the equivalent photon approximation, and the other using lowest-order quantum electrodynamics (QED); the latter includes the photon virtuality. The cross section, pair mass, rapidity and angular distributions are in good agreement with both calculations. The pair transverse momentum, p{sub T}, spectrum agrees with the QED calculation, but not with the equivalent photon approach. We set limits on higher-order contributions to the cross section. The e{sup +} and e{sup -} p{sub T} spectra are similar, with no evidence for interference effects due to higher-order diagrams.
Date: April 7, 2004
Creator: Adams, J.; Adler, C.; Aggarwal, M. M.; Ahammed, Z.; Allgower, C.; Amonett, J. et al.
Object Type: Article
System: The UNT Digital Library
Open Charm Yields in d+Au Collisions at sqrt(sNN) = 200 GeV (open access)

Open Charm Yields in d+Au Collisions at sqrt(sNN) = 200 GeV

Mid-rapidity open charm spectra from direct reconstruction of D{sup 0}({bar D}{sup 0}) {yields} K{sup {-+}} {pi}{sup {+-}} in d+Au collisions and indirect electron/positron measurements via charm semileptonic decays in p+p and d+Au collisions at {radical}s{sub NN} = 200 GeV are reported. The D{sup 0}({bar D}{sup 0}) spectrum covers a transverse momentum (p{sub T}) range of 0.1 < p{sub T} < 3 GeV/c whereas the electron spectra cover a range of 1 < p{sub T} < 4 GeV/c. The electron spectra show approximate binary collision scaling between p+p and d+Au collisions. From these two independent analyses, the differential cross section per nucleon-nucleon binary interaction at mid-rapidity for open charm production from d+Au collisions at RHIC is d{sigma}{sub c{bar c}}{sup NN}/dy = 0.30 {+-} 0.04 (stat.) {+-} 0.09(syst.) mb. The results are compared to theoretical calculations. Implications for charmonium results in A+A collisions are discussed.
Date: January 7, 2005
Creator: Adams, J.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D.; Arkhipkin, D. et al.
Object Type: Article
System: The UNT Digital Library
Weatherization Assistance Program Technical Assistance Center (open access)

Weatherization Assistance Program Technical Assistance Center

The following is a synopsis of the major achievements attributed to the operation of the Weatherization Assistance Program Technical Assistance Center (WAPTAC) by the National Association for State Community Services Programs (NASCSP). During the past five years, the WAPTAC has developed into the premier source for information related to operating the Weatherization Assistance Program (WAP) at the state and local levels. The services provide through WAPTAC include both virtual technical support as well as hands-on training and instruction in classroom and in the field. The WAPTAC achieved several important milestones during its operation including the establishment of a national Weatherization Day now celebrated in most states, the implementation of a comprehensive Public Information Campaign (PIC) to raise the awareness of the Program among policy makers and the public, the training of more than 150 new state managers and staff as they assume their duties in state offices around the country, and the creation and support of a major virtual information source on the Internet being accessed by thousands of staff each month. The Weatherization Assistance Program Technical Assistance Center serves the Department of Energy's (DOE) Office of Weatherization and Intergovernmental Program as a valuable training and technical assistance resource for …
Date: January 7, 2009
Creator: Adams, Robert
Object Type: Report
System: The UNT Digital Library
Confirmatory Survey Report for Portions of the Auxiliary Building Structural Surfaces and Turbine Building Embedded Piping, Rancho Seco Nuclear Generating Station, Herald, CA (open access)

Confirmatory Survey Report for Portions of the Auxiliary Building Structural Surfaces and Turbine Building Embedded Piping, Rancho Seco Nuclear Generating Station, Herald, CA

During the period of October 15 and 18, 2007, ORISE performed confirmatory radiological survey activities which included beta and gamma structural surface scans and beta activity direct measurements within the Auxiliary Building, beta or gamma scans within Turbine Building embedded piping, beta activity determinations within Turbine Building Drain 3-1-27, and gamma scans and the collection of a soil sample from the clay soils adjacent to the Lower Mixing Box.
Date: December 7, 2007
Creator: Adams, W. C.
Object Type: Report
System: The UNT Digital Library
Revised─Confirmatory Survey Report for Portions of the Auxiliary Building Structural Surfaces and Turbine Building Embedded Piping, Rancho Seco Nuclear Generating Station, Herald, California (open access)

Revised─Confirmatory Survey Report for Portions of the Auxiliary Building Structural Surfaces and Turbine Building Embedded Piping, Rancho Seco Nuclear Generating Station, Herald, California

During the period of October 15 and 18, 2007, ORISE performed confirmatory radiological survey activities which included beta and gamma structural surface scans and beta activity direct measurements within the Auxiliary Building, beta or gamma scans within Turbine Building embedded piping, beta activity determinations within Turbine Building Drain 3-1-27, and gamma scans and the collection of a soil sample from the clay soils adjacent to the Lower Mixing Box.
Date: December 7, 2007
Creator: Adams, W. C.
Object Type: Report
System: The UNT Digital Library
Iran: Regional Perspectives and U.S. Policy (open access)

Iran: Regional Perspectives and U.S. Policy

This report provides a description of Iran's neighbors' policies and interests, options for Congressional consideration, and an analysis of potential regional implications
Date: October 7, 2009
Creator: Addis, Casey L.; Blanchard, Christopher M.; Katzman, Kenneth; Migdalovitz, Carol; Nichol, Jim; Sharp, Jeremy M. et al.
Object Type: Report
System: The UNT Digital Library
A DATA-CENTERED COLLABORATION PORTAL TO SUPPORT GLOBAL CARBON-FLUX ANALYSIS (open access)

A DATA-CENTERED COLLABORATION PORTAL TO SUPPORT GLOBAL CARBON-FLUX ANALYSIS

Carbon-climate, like other environmental sciences, has been changing. Large-scalesynthesis studies are becoming more common. These synthesis studies are often conducted by science teams that are geographically distributed and on datasets that are global in scale. A broad array of collaboration and data analytics tools are now available that could support these science teams. However, building tools that scientists actually use is hard. Also, moving scientists from an informal collaboration structure to one mediated by technology often exposes inconsistencies in the understanding of the rules of engagement between collaborators. We have developed a scientific collaboration portal, called fluxdata.org, which serves the community of scientists providing and analyzing the global FLUXNET carbon-flux synthesis dataset. Key things we learned or re-learned during our portal development include: minimize the barrier to entry, provide features on a just-in-time basis, development of requirements is an on-going process, provide incentives to change leaders and leverage the opportunity they represent, automate as much as possible, and you can only learn how to make it better if people depend on it enough to give you feedback. In addition, we also learned that splitting the portal roles between scientists and computer scientists improved user adoption and trust. The fluxdata.org portal …
Date: April 7, 2009
Creator: Agarwal, Deborah A.; Humphrey, Marty; Beekwilder, Norm; Jackson, Keith; Goode, Monte & van Ingen, Catharine
Object Type: Article
System: The UNT Digital Library
Aging and Fracture of Human Cortical Bone and Tooth Dentin (open access)

Aging and Fracture of Human Cortical Bone and Tooth Dentin

Mineralized tissues, such as bone and tooth dentin, serve as structural materials in the human body and, as such, have evolved to resist fracture. In assessing their quantitative fracture resistance or toughness, it is important to distinguish between intrinsic toughening mechanisms which function ahead of the crack tip, such as plasticity in metals, and extrinsic mechanisms which function primarily behind the tip, such as crack bridging in ceramics. Bone and dentin derive their resistance to fracture principally from extrinsic toughening mechanisms which have their origins in the hierarchical microstructure of these mineralized tissues. Experimentally, quantification of these toughening mechanisms requires a crack-growth resistance approach, which can be achieved by measuring the crack-driving force, e.g., the stress intensity, as a function of crack extension ("R-curve approach"). Here this methodology is used to study of the effect of aging on the fracture properties of human cortical bone and human dentin in order to discern the microstructural origins of toughness in these materials.
Date: May 7, 2008
Creator: Ager, Joel; Koester, Kurt J.; Ager, Joel W., III & Ritchie, Robert O.
Object Type: Article
System: The UNT Digital Library
Stability and Regeneration of Catalysts for the Destruction of Tars from Bio-mass Black Liquor Gasification (open access)

Stability and Regeneration of Catalysts for the Destruction of Tars from Bio-mass Black Liquor Gasification

The goal of this project was to develop catalytic materials and processes that would be effective in the destruction of tars formed during the gasification of black liquor and biomass. We report here the significant results obtained at the conclusion of this two year project.
Date: September 7, 2004
Creator: Agrawal, Pradeep
Object Type: Report
System: The UNT Digital Library
Simultaneous Observations of PKS 2155--304 with H.E.S.S., Fermi, RXTE and ATOM: Spectral Energy Distributions and Variability in a Low State (open access)

Simultaneous Observations of PKS 2155--304 with H.E.S.S., Fermi, RXTE and ATOM: Spectral Energy Distributions and Variability in a Low State

We report on the first simultaneous observations that cover the optical, X-ray, and high-energy gamma-ray bands of the BL Lac object PKS 2155-304. The gamma-ray bands were observed for 11 days, between 2008 August 25 and 2008 September 6 (MJD 54704-54715), jointly with the Fermi Gamma-ray Space Telescope and the HESS atmospheric Cherenkov array, providing the first simultaneous MeV-TeV spectral energy distribution (SED) with the new generation of {gamma}-ray telescopes. The ATOM telescope and the RXTE and Swift observatories provided optical and X-ray coverage of the low-energy component over the same time period. The object was close to the lowest archival X-ray and very high energy (VHE; >100 GeV) state, whereas the optical flux was much higher. The light curves show relatively little ({approx}30%) variability overall when compared to past flaring episodes, but we find a clear optical/VHE correlation and evidence for a correlation of the X-rays with the high-energy spectral index. Contrary to previous observations in the flaring state, we do not find any correlation between the X-ray and VHE components. Although synchrotron self-Compton models are often invoked to explain the SEDs of BL Lac objects, the most common versions of these models are at odds with the correlated …
Date: May 7, 2009
Creator: Aharonian, F.; Akhperjanian, A. G.; Anton, G.; Barres de Almeida, U.; Bazer-Bachi, A. R.; Becherini, Y. et al.
Object Type: Article
System: The UNT Digital Library
Trade Legislation in the 106th Congress: An Overview (open access)

Trade Legislation in the 106th Congress: An Overview

The 106th Congress completed action on a number of major trade initiatives. The impact on American firms and workers was a paramount concern in the passage of this legislation. Most notably, bills were passed to establish "normal trade relations" with China, deepen economic ties with the countries of Sub-Saharan Africa, enhance trade benefits for 24 Caribbean Basin countries, and to ease trade sanctions on Cuba and other countries. Congress also voted to maintain U.S. participation in the World Trade Organization (WTO), as well as worked with the Clinton Administration to pass replacement legislation for the Foreign Sales Corporation (FSC) tax benefit for U.S. exports. The latter action averted, at least until mid-2001, the imposition of punitive tariffs by the European Union on an estimated $4 billion in U.S. exports.
Date: March 7, 2001
Creator: Ahearn, Raymond J. & Jones, Vivian C.
Object Type: Report
System: The UNT Digital Library
Transatlantic Regulatory Cooperation: A Possible Role for Congress (open access)

Transatlantic Regulatory Cooperation: A Possible Role for Congress

This report focuses on the creation of the Transatlantic Economic Council; the role of legislatures in the regulatory process; and the Transatlantic Legislators' Dialogue and its new role as an advisor to transatlantic regulatory efforts.
Date: November 7, 2008
Creator: Ahearn, Raymond J. & Morelli, Vincent
Object Type: Report
System: The UNT Digital Library
Observation of high energy atmospheric neutrinos with antarctic muon and neutrino detector array (open access)

Observation of high energy atmospheric neutrinos with antarctic muon and neutrino detector array

The Antarctic Muon and Neutrino Detector Array (AMANDA) began collecting data with ten strings in 1997. Results from the first year of operation are presented. Neutrinos coming through the Earth from the Northern Hemisphere are identified by secondary muons moving upward through the array. Cosmic rays in the atmosphere generate a background of downward moving muons, which are about 10{sup 6} times more abundant than the upward moving muons. Over 130 days of exposure, we observed a total of about 300 neutrino events. In the same period, a background of 1.05 x 10{sup 9} cosmic ray muon events was recorded. The observed neutrino flux is consistent with atmospheric neutrino predictions. Monte Carlo simulations indicate that 90 percent of these events lie in the energy range 66 GeV to 3.4 TeV. The observation of atmospheric neutrinos consistent with expectations establishes AMANDA-B10 as a working neutrino telescope.
Date: May 7, 2002
Creator: Ahrens, J.; Andres, E.; Bai, X.; Barouch, G.; Barwick, S. W.; Bay, R. C. et al.
Object Type: Article
System: The UNT Digital Library
Reservoir characterization and performance predictions for the E.N. Woods lease (open access)

Reservoir characterization and performance predictions for the E.N. Woods lease

The task of this work was to evaluate the past performance of the E.N. WOODS Unit and to forecast its future economic performance by taking into consideration the geology, petrophysics and production history of the reservoir. The Decline Curve Analysis feature of the Appraisal of Petroleum Properties including Taxation Systems (EDAPT) software along with the Production Management Systems (PMS) software were used to evaluate the original volume of hydrocarbon in place and estimate the reserve. The Black Oil Simulator (BOAST II) was then used to model the waterflooding operation and estimate the incremental oil production attributable to the water injection. BOAST II was also used to predict future performance of the reservoir.
Date: July 7, 2000
Creator: Aka-Milan, Francis A.
Object Type: Report
System: The UNT Digital Library