The Community Climate System Model Project from an Interagency Perspective (open access)

The Community Climate System Model Project from an Interagency Perspective

In 2007, the Intergovernmental Panel on Climate Change (IPCC) will publish its Fourth Assessment Report of the Scientific Basis of Climate Change (AR4). A significant portion of the AR4 will be the analysis of coupled general circulation model (GCM) simulations of the climate of the past century as well as scenarios of future climates under prescribed emission scenarios. Modeling groups worldwide have contributed to AR4, including three from the U.S., the Community Climate System Model (CCSM) project, the National Aeronautics and Space Administration (NASA) Goddard Institute for Space Sciences, and the National Oceanic and Atmospheric Administration (NOAA) Geophysical Fluid Dynamics Laboratory (GFDL). This collection of model results is providing a wealth of new information that will be used to examine the state of climate science, the potential impacts from climate changes, and the policy consequences that they imply. Our focus here is on the CCSM project. Although it is centered at the National Center for Atmospheric Research (NCAR), the CCSM version 3 (CCSM3) was designed, developed, and applied in a uniquely distributed fashion with participation by many institutions. This model has produced some of the most scientifically complete and highest resolution simulations of climate change to date, thanks to the …
Date: June 16, 2005
Creator: Bader, D C; Bamzai, A; Fein, J; Patrinos, A & Leinen, M
Object Type: Article
System: The UNT Digital Library
Vibrational Spectra of Dense Molecular Fluids in a Laser-Heated DAC: Implications to Shock Compressed Fluids (open access)

Vibrational Spectra of Dense Molecular Fluids in a Laser-Heated DAC: Implications to Shock Compressed Fluids

Recent technical advances have made it possible to obtain very useful spectroscopic information about simple molecules at temperatures and pressures exceeding 2000K and 10 GPa inside a diamond-anvil cell, which is well above any melting point for such systems. This is accomplished by obtaining vibrational spectra via Coherent Anti-Stokes Raman Spectroscopy in conjunction with CW laser heating using a tungsten toroid as a laser target. By the simultaneous use of these techniques, vibrational spectra with relatively high signal to noise can be obtained despite the enormous thermal background generated by the incandescence of extremely hot laser heated material. Temperatures can be measured not only by fitting the Planck radiation to a graybody, but by the spectroscopic evidence of a Boltzmann distribution of molecules in their vibrationally excited quantum levels. Additionally, this technique allows for obtaining data at pressures and temperatures outside the region between the shock hugoniot and isentrope, complementing shock wave experiments.
Date: July 16, 2003
Creator: Baer, B. J. & Yoo, C. S.
Object Type: Article
System: The UNT Digital Library
Double Shell Tank (DST) Monitor and Control Subsystem Definition Report (open access)

Double Shell Tank (DST) Monitor and Control Subsystem Definition Report

The system description of the Double-Shell Tank (DST) Monitor and Control Subsystem establishes the system boundaries and describes the interface of the DST Monitor and Control Subsystem with new and existing systems that are required to accomplish the Waste Feed Delivery (WFD) mission.
Date: March 16, 2000
Creator: Bafus, Ron R.
Object Type: Report
System: The UNT Digital Library
Nuclear Data Sheets for 225Fr (open access)

Nuclear Data Sheets for 225Fr

Nuclear structure data pertaining to {sup 225}Fr have been evaluated, and incorporated into the ENSDF data file. This evaluation includes literature available by 16 May 2005 and supersedes the previous publication for {sup 225}Fr (Y.A. Akovali, ''Nuclear Data Sheets 60, 617 (1990)'', literature cutoff date 1 June 1989). Data have been incorporated from the following references: 1987Co19, 1997BuO3 and 2003AuO3.
Date: May 16, 2005
Creator: Baglin, Coral M.
Object Type: Report
System: The UNT Digital Library
Crossing a coupling spin resonance with an RF dipole (open access)

Crossing a coupling spin resonance with an RF dipole

None
Date: October 16, 2000
Creator: Bai, M. & Roser, T.
Object Type: Article
System: The UNT Digital Library
POLARIZED PROTON COLLISIONS AT RHIC. (open access)

POLARIZED PROTON COLLISIONS AT RHIC.

The Relativistic Heavy Ion Collider provides not only collisions of ions but also collisions of polarized protons. In a circular accelerator, the polarization of polarized proton beam can be partially or fully lost when a spin depolarizing resonance is encountered. To preserve the beam polarization during acceleration, two full Siberian snakes were employed in RHIC. In 2002, polarized proton beams were first accelerated to 100 GeV and collided in RHIC. Beams were brought into collisions with longitudinal polarization at the experiments STAR and PHENIX by using spin rotators. Optimizing polarization transmission efficiency and improving luminosity performance are significant challenges. Currently, the luminosity lifetime in RHIC is limited by the beam-beam effect. The current state of RHIC polarized proton program, including its dedicated physics run in 2005 and efforts to optimize luminosity production in beam-beam limited conditions are reported.
Date: May 16, 2005
Creator: Bai, M.; Ahrens, L.; Alekseev, I. G.; Alessi, J. & AL., ET
Object Type: Article
System: The UNT Digital Library
Observations of Snake Resonance in RHIC. (open access)

Observations of Snake Resonance in RHIC.

Siberian snakes now become essential in the polarized proton acceleration. With proper configuration of Siberian snakes, the spin precession tune of the beam becomes 1/2 which avoids all the spin depolarizing resonance. However, the enhancement of the perturbations on the spin motion can still occur when the spin precession tune is near some low order fractional numbers, called snake resonances, and. the beam can be depolarized when passing through the resonance. The snake resonances have been confirmed in the spin tracking calculations, and observed in RHIC with polarized proton beam. Equipped with two full Siberian snakes in each ring, RHIC provides us a perfect facility for snake resonance studies. This paper presents latest experimental results. New insights are also discussed.
Date: May 16, 2005
Creator: Bai, M.; Huang, H.; MacKay, W. W.; Pitisyn, V.; Roser, T. & Tepikian, S.
Object Type: Article
System: The UNT Digital Library
Method of Evaluating, Expanding, and Collapsing Connectivity Regions Within Dynamic Systems (open access)

Method of Evaluating, Expanding, and Collapsing Connectivity Regions Within Dynamic Systems

An automated process defines and maintains connectivity regions within a dynamic network. The automated process requires an initial input of a network component around which a connectivity region will be defined. The process automatically and autonomously generates a region around the initial input, stores the region's definition, and monitors the network for a change. Upon detecting a change in the network, the effect is evaluated, and if necessary the regions are adjusted and redefined to accommodate the change. Only those regions of the network affected by the change will be updated. This process eliminates the need for an operator to manually evaluate connectivity regions within a network. Since the automated process maintains the network, the reliance on an operator is minimized; thus, reducing the potential for operator error. This combination of region maintenance and reduced operator reliance, results in a reduction of overall error.
Date: November 16, 2004
Creator: Bailey, David A.
Object Type: Patent
System: The UNT Digital Library
Dynamic Maintenance and Visualization of Molecular Surfaces (open access)

Dynamic Maintenance and Visualization of Molecular Surfaces

Molecular surface computations are often necessary in order to perform synthetic drug design. A critical step in this process is the computation and update of an exact boundary representation for the molecular surface (e.g. the Lee-Richards surface). In this paper they introduce efficient techniques for computing a molecular surface boundary representation as a set of NURBS (non-uniform rational B-splines) patches. This representation introduces for molecules the same geometric data structure used in the solid modeling community and enables immediate access to a wide range of modeling operations and techniques. Furthermore, this allows the use of any general solid modeling or visualization system as a molecular modeling interface. However, using such a representation in a molecular modeling environment raises several efficiency and update constraints, especially in a dynamic setting. For example, changes in the probe radius result in both geometric and topological changes to the set of patches. The techniques provide the option of trading accuracy of the representation for the efficiency of the computation, while still tracking the changes in the set of patches. In particular, they discuss two main classes of dynamic updates: one that keeps the topology of the molecular configuration fixed, and a more complicated case where …
Date: December 16, 2004
Creator: Bajaj, C L; Pascucci, V; Shamir, A; Holt, R J & Netravali, A N
Object Type: Article
System: The UNT Digital Library
Matching grant program for university nuclear engineering education (open access)

Matching grant program for university nuclear engineering education

The grant augmented funds from Westinghouse Electric Co. to enhance the Nuclear Engineering program at KSU. The program was designed to provide educational opportunities and to train engineers for careers in the nuclear industry. It provided funding and access to Westinghouse proprietary design codes for graduate and undergraduate studies on topics of current industrial importance. Students had the opportunity to use some of the most advanced nuclear design tools in the industry and to work on actual design problems. The WCOBRA/TRAC code was used to simulate loss of coolant accidents (LOCAs).
Date: October 16, 2002
Creator: Bajorek, Stephen M.
Object Type: Report
System: The UNT Digital Library
Noise Suppression and Enhanced Focusability in Plasma Raman Amplifier with Multi-frequency Pump (open access)

Noise Suppression and Enhanced Focusability in Plasma Raman Amplifier with Multi-frequency Pump

Laser pulse compression/amplification through Raman backscattering in plasmas can be facilitated by using multi-frequency pump laser beams. The efficiency of amplification is increased by suppressing the Raman instability of thermal fluctuations and seed precursors. Also the focusability of the amplified radiation is enhanced due to the suppression of large-scale longitudinal speckles in the pump wave structure.
Date: June 16, 2003
Creator: Balakin, A. A.; Fraiman, G. M.; Fisch, N. J. & Malkin, V. M.
Object Type: Report
System: The UNT Digital Library
ENERGY-10 PV: Photovoltaics, A New Capability (Preprint) (open access)

ENERGY-10 PV: Photovoltaics, A New Capability (Preprint)

This is one of two companion papers that describe the ENERGY-10 PV design-tool computer simulation program. The other paper is titled ''Hourly Simulation of Grid-Connected PV Systems Using Realistic Building Loads.'' While this paper focuses on the implementation method, the companion paper focuses on the PV aspects of the program. The case study in this paper is a residential building application, whereas the case study in the companion paper is a commercial application with an entirely different building load characteristic. Together, they provide a balanced view.
Date: February 16, 2001
Creator: Balcomb, J. D.; Hayter, S. J. & Weaver, N. L.
Object Type: Article
System: The UNT Digital Library
The Evolution of a Hierarchical Partitioning Algorithm for Large-Scale Scientific Data: Three Steps of Increasing Complexity (open access)

The Evolution of a Hierarchical Partitioning Algorithm for Large-Scale Scientific Data: Three Steps of Increasing Complexity

As scientific data sets grow exponentially in size, the need for scalable algorithms that heuristically partition the data increases. In this paper, we describe the three-step evolution of a hierarchical partitioning algorithm for large-scale spatio-temporal scientific data sets generated by massive simulations. The first version of our algorithm uses a simple top-down partitioning technique, which divides the data by using a four-way bisection of the spatio-temporal space. The shortcomings of this algorithm lead to the second version of our partitioning algorithm, which uses a bottom-up approach. In this version, a partition hierarchy is constructed by systematically agglomerating the underlying Cartesian grid that is placed on the data. Finally, the third version of our algorithm utilizes the intrinsic topology of the data given in the original scientific problem to build the partition hierarchy in a bottom-up fashion. Specifically, the topology is used to heuristically agglomerate the data at each level of the partition hierarchy. Despite the growing complexity in our algorithms, the third version of our algorithm builds partition hierarchies in less time and is able to build trees for larger size data sets as compared to the previous two versions.
Date: April 16, 2003
Creator: Baldwin, C.; Eliassi-Rad, T.; Abdulla, G. & Critchlow, T.
Object Type: Article
System: The UNT Digital Library
The Endangered Species Act (ESA), Sound Science, and the Courts (open access)

The Endangered Species Act (ESA), Sound Science, and the Courts

None
Date: July 16, 2003
Creator: Baldwin, Pamela
Object Type: Report
System: The UNT Digital Library
The Endangered Species Act and "Sound Science" (open access)

The Endangered Species Act and "Sound Science"

This report provides a context for evaluating legislative proposals through examples of how science has been used in selected cases, a discussion of the nature and role of science in general, and its role in the Endangered Species Act (ESA) process in particular, together with general and agency information quality requirements and policies, and a review of how the courts have viewed agency use of science.
Date: July 16, 2002
Creator: Baldwin, Pamela & Corn, M. Lynne
Object Type: Report
System: The UNT Digital Library
Evaluating Radionuclide Air Emission Stack Sampling Systems (open access)

Evaluating Radionuclide Air Emission Stack Sampling Systems

The Pacific Northwest National Laboratory (PNNL) operates a number of research and development (R&D) facilities for the U.S. Department of Energy at the Hanford Site, Washington. These facilities are subject to Clean Air Act regulations that require sampling of radionuclide air emissions from some of these facilities. A revision to an American National Standards Institute (ANSI) standard on sampling radioactive air emissions has recently been incorporated into federal and state regulations and a re-evaluation of affected facilities is being performed to determine the impact. The revised standard requires a well-mixed sampling location that must be demonstrated through tests specified in the standard. It also carries a number of maintenance requirements, including inspections and cleaning of the sampling system. Evaluations were performed in 2000 – 2002 on two PNNL facilities to determine the operational and design impacts of the new requirements. The evaluation included inspection and cleaning maintenance activities plus testing to determine if the current sampling locations meet criteria in the revised standard. Results show a wide range of complexity in inspection and cleaning activities depending on accessibility of the system, ease of removal, and potential impact on building operations (need for outages). As expected, these High Efficiency Particulate Air …
Date: December 16, 2002
Creator: Ballinger, Marcel Y.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Automobile and Light Truck Fuel Economy: Is CAFE Up to Standards? (open access)

Automobile and Light Truck Fuel Economy: Is CAFE Up to Standards?

This report discusses on refocusing on fuel economy: SUVs OPEC and Kyoto, Cafe in Congress and legislation.
Date: September 16, 2002
Creator: Bamberger, Robert
Object Type: Report
System: The UNT Digital Library
Oil and Gas: Supply Issues After Katrina (open access)

Oil and Gas: Supply Issues After Katrina

None
Date: September 16, 2005
Creator: Bamberger, Robert L. & Kumins, Lawrence C.
Object Type: Report
System: The UNT Digital Library
Planning for Site Transition to Long-Term Stewardship: Identification of Requirements and Issues (open access)

Planning for Site Transition to Long-Term Stewardship: Identification of Requirements and Issues

A systematic methodology is presented and applied for the identification of requirements and issues pertaining to the planning for, and transition to, long term stewardship (LTS). The method has been applied to three of the twelve identified LTS functions. The results of the application of the methodology to contaminated and uncontaminated federal real property in those three functions are presented. The issues that could be seen as impediments to the implementation of LTS are also identified for the three areas under consideration. The identified requirements are significant and in some cases complex to implement. It is clear that early and careful planning is required in all circumstances.
Date: May 16, 2002
Creator: Banaee, J.
Object Type: Article
System: The UNT Digital Library
A New Assessment of the LOFT-Wyle Blowdown Test WSB03R Using RELAP5-3D (open access)

A New Assessment of the LOFT-Wyle Blowdown Test WSB03R Using RELAP5-3D

The RELAP-3D (version bt03) computer program was used to assess the LOFT-Wyle blowdown test (WSB03R). The primary goal of this new assessment is to represent faithfully the experimental facility and instrumentation using the latest three-dimensional fluid flow modeling capability available in RELAP5-3D. In addition, since RELAP5-3D represents a relatively new and significant upgrade to the capabilities of the RELAP5 series of computer programs, this study serves to add to its growing assessment base. The LOFT-Wyle Transient Fluid Calibration test facility consisted of an approximately 5.4m3 pressure vessel with a flow skirt which created an annulus that acted as a downcomer. An instrumented blowdown loop with an orfice was connected to the downcomer. This facility, built to calibrate the orfices used in several of the LOFT experiments, simulated the LOFT reactor vessel and broken loop cold leg. For the present assessment an existing RELAP5 model developed at INEEL was corrected and upgraded. The model corrections included: (1) employing the proper measured downcomer thickness, (2) positioning the experimental instrumentation in its correct location, and (3) setting the fluid conditions to their measured initial values. Model upgrades included: (1) use of a more finely-detailed fluid component nodalization, (2) explicit modeling of the experimental …
Date: April 16, 2002
Creator: Bandini, B. R.; Aumiller, D. L. & Tomlinson, E. T.
Object Type: Article
System: The UNT Digital Library
Development of pseudo-random binary gratings and arrays for calibration of surface profile metrology tools (open access)

Development of pseudo-random binary gratings and arrays for calibration of surface profile metrology tools

Optical Metrology tools, especially for short wavelength (EUV and X-Ray), must cover a wide range of spatial frequencies from the very low, which affects figure, to the important mid-spatial frequencies and the high spatial frequency range, which produces undesirable flair. A major difficulty in using surface profilometers arises due to the unknown Modulation Transfer Function (MTF) of the instruments. Therefore, accurate calibration of profilometers, the understanding of their MTF limitations, and cross calibration between tools represents a considerable challenge for quantitative optical metrology. In previous work the instrumental MTF of a surface profiler was precisely measured using reference test surfaces based on binary pseudo-random (BPR) gratings. Here, they present results of fabricating and using two-dimensional (2D) BPR arrays that allow for a direct 2D calibration of the instrumental MTF. BPR sequences are widely used in engineering and communication applications such as Global Position System, and wireless communication protocol. The ideal BPR pattern has a flat 'white noise' response over the entire range of spatial frequencies of interest. The BPR array used here is based on the Uniformly Redundant Array prescription initially used for x-ray and gamma ray astronomy applications. The URA's superior imaging capability originates from the fact that its …
Date: January 16, 2009
Creator: Barber, Samuel K.; Soldate, Paul; Anderson, Erik; Cambie, Rosanna; McKinney, Wayne R.; Takacs, Peter Z. et al.
Object Type: Article
System: The UNT Digital Library
Development of pseudo-random binary gratings and arrays for calibration of surface profile metrology tools (open access)

Development of pseudo-random binary gratings and arrays for calibration of surface profile metrology tools

None
Date: January 16, 2009
Creator: Barber, Samuel K.; Soldate, Paul; Anderson, Erik; Cambie, Rosanna; McKinney, Wayne R.; Takacs, Peter Z. et al.
Object Type: Article
System: The UNT Digital Library
Managing Carbon Regulatory Risk in Utility Resource Planning:Current Practices in the Western United States (open access)

Managing Carbon Regulatory Risk in Utility Resource Planning:Current Practices in the Western United States

Concerns about global climate change have substantially increased the likelihood that future policy will seek to minimize carbon dioxide emissions. Assuch, even today, electric utilities are making resource planning and investment decisions that consider the possible implications of these future carbon regulations. In this article, we examine the manner in which utilities assess the financial risks associated with future carbon regulations within their long-term resource plans. We base our analysis on a review of the most recent resource plans filed by fifteen electric utilities in the Western United States. Virtually all of these utilities made some effort to quantitatively evaluate the potential cost of future carbon regulations when analyzing alternate supply- and demand-side resource options for meeting customer load. Even without Federal climate regulation in the U.S., the prospect of that regulation is already having an impact on utility decision-making and resource choices. That said, the methods and assumptions used by utilities to analyze carbon regulatory risk, and the impact of that analysis on their choice of a particular resource strategy, vary considerably, revealing a number of opportunities for analytic improvement. Though our review focuses on a subset of U.S. electric utilities, this work holds implications for all electric utilities …
Date: May 16, 2008
Creator: Barbose, Galen; Wiser, Ryan; Phadke, Amol & Goldman, Charles
Object Type: Article
System: The UNT Digital Library
Summing Planar Bosonic Open Strings (open access)

Summing Planar Bosonic Open Strings

In earlier work, planar graphs of massless {phi}{sup 3} theory were summed with the help of the light cone world sheet picture and the mean field approximation. In the present article, the same methods are applied to the problem of summing planar bosonic open strings. They find that in the ground state of the system, string boundaries form a condensate on the world sheet, and a new string emerges from this summation. Its slope is always greater than the initial slope, and it remains non-zero even when the initial slope is set equal to zero. If they assume the initial string tends to a field a theory in the zero slope limit, this result provides evidence for string formation in field theory.
Date: February 16, 2006
Creator: Bardakci, Korkut
Object Type: Article
System: The UNT Digital Library