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8:1 thermal cavity problem (open access)

8:1 thermal cavity problem

We present results for the 8:1 thermal cavity problem using FIDAP on 3 meshes--each using 3 elements. A brief summary of related results is also included. This contribution comes via the rather versatile and general commercial finite element code, FIDAP. This code still offers the user a wide selection with respect to element choices, statement of governing equations, (e.g., advective form, divergence form) implicit time integrators (variable-step or fixed step, first-order or second-order), and solution techniques for both the nonlinear and linear sets of equations. We have tested quite a number of these variations on this problem; here we report on an interesting subset and will present the remainder at the conference.
Date: October 11, 2000
Creator: Gresho, P M & Sutton, S
System: The UNT Digital Library
50 MW X-BAND RF SYSTEM FOR A PHOTOINJECTOR TEST STATION AT LLNL (open access)

50 MW X-BAND RF SYSTEM FOR A PHOTOINJECTOR TEST STATION AT LLNL

In support of X-band photoinjector development efforts at LLNL, a 50 MW test station is being constructed to investigate structure and photocathode optimization for future upgrades. A SLAC XL-4 klystron capable of generating 50 MW, 1.5 microsecond pulses will be the high power RF source for the system. Timing of the laser pulse on the photocathode with the applied RF field places very stringent requirements on phase jitter and drift. To achieve these requirements, the klystron will be powered by a state of the art, solid-state, high voltage modulator. The 50 MW will be divided between the photoinjector and a traveling wave accelerator section. A high power phase shifter is located between the photoinjector and accelerator section to adjust the phasing of the electron bunches with respect to the accelerating field. A variable attenuator is included on the input of the photoinjector. The distribution system including the various x-band components is being designed and constructed. In this paper, we will present the design, layout, and status of the RF system.
Date: March 11, 2011
Creator: Marsh, R A; Anderson, S G; Barty, C J; Beer, G K; Cross, R R; Ebbers, C A et al.
System: The UNT Digital Library
10th Workshop on Crystalline Silicon Solar Cell Materials and Processes: Extended Abstracts and Papers from the Workshop, Copper Mountain Resort; August 14-16, 2000 (open access)

10th Workshop on Crystalline Silicon Solar Cell Materials and Processes: Extended Abstracts and Papers from the Workshop, Copper Mountain Resort; August 14-16, 2000

The 10th Workshop provided a forum for an informal exchange of technical and scientific information between international researchers in the photovoltaic and non-photovoltaic fields. Discussions included the various aspects of impurities and defects in silicon-their properties, the dynamics during device processing, and their application for developing low-cost processes for manufacturing high-efficiency silicon solar cells. Sessions and panel discussions also reviewed thin-film crystalline-silicon PV, advanced cell structures, new processes and process characterization techniques, and future manufacturing requirements to meet the ambitious expansion goals described in the recently released US PV Industry Roadmap. The Workshop also provided an excellent opportunity for researchers in private industry and at universities to recognize a mutual need for future collaborative research. The three-day workshop consisted of presentations by invited speakers, followed by discussion sessions. In addition, there was two poster sessions presenting the latest research and development results. The subjects discussed included: solar cell processing, light-induced degradation, gettering and passivation, crystalline silicon growth, thin-film silicon solar cells, and impurities and defects. Two special sessions featured at this workshop: advanced metallization and interconnections, and characterization methods.
Date: August 11, 2000
Creator: Sopori, B. L.; Gee, J.; Kalejs, J.; Saitoh, R.; Stavola, M.; Swanson, D. et al.
System: The UNT Digital Library
12th International Workshop on Plant Membrane Biology (open access)

12th International Workshop on Plant Membrane Biology

This report is on 12th International Workshop on Plant Membrane Biology
Date: August 11, 2001
Creator: Spalding, Edgar P.
System: The UNT Digital Library
2005 Quantum Control of Light and Matter - Conference July 31 - August 5, 2005 (open access)

2005 Quantum Control of Light and Matter - Conference July 31 - August 5, 2005

This report is about Quantum Control of Light and Matter Gordon Research Conference
Date: September 11, 2006
Creator: Corkum, Paul B.
System: The UNT Digital Library
2006 Multiphoton Processes Gordon Conference - June 11-16 (open access)

2006 Multiphoton Processes Gordon Conference - June 11-16

The first Gordon Research Conference on Multiphoton Processes, was held in 1982. The meeting continues to evolve as it embraces both the rapid technological and intellectual growth in the field as well as the multi-disciplinary expertise of the participants. Current areas of interest include: (1) Ionization/Dissociation of Atoms and Molecules in Intense Laser Fields; (2) Frequency Domain Multi-Photon and Multiple-Resonance Spectroscopies of Molecules; (3) Time-Resolved Photoelectron Spectroscopy; (4) Ultrafast Pump-Probe Spectroscopy; (5) Coherent Strong-Field Manipulation of Atoms and Molecules; (6) High-Harmonic Generation; (7) Attosecond Pulse Generation and Measurement; and (8) Super-Intense Laser-Matter Interactions. In developing the program, the conference organizers will strive to blur traditional disciplinary boundaries, involving chemists, physicists, and optical engineers, representing both experiment and theory, as presenters and discussion leaders. The broad range of expertise and different perspectives of attendees should provide a stimulating and unique environment for solving problems and developing new ideas in this rapidly evolving field.
Date: June 11, 2006
Creator: Jones, Robert Rivers
System: The UNT Digital Library
2010 IRON-SULFUR ENZYMES GORDON RESEARCH CONFERENCE, JUNE 6-11, 2010 (open access)

2010 IRON-SULFUR ENZYMES GORDON RESEARCH CONFERENCE, JUNE 6-11, 2010

Iron-sulfur (FeS) centers are essential for biology and inspirational in chemistry. These protein cofactors are broadly defined as active sites in which Fe is coordinated by S-donor ligands, often in combination with extra non-protein components, for example, additional metal atoms such as Mo and Ni, and soft ligands such as CN{sup -} and CO. Iron-sulfur centers are inherently air sensitive: they are found in essentially all organisms and it is possible that they were integral components of the earliest forms of life, well before oxygen (O{sub 2}) appeared. Proteins containing FeS cofactors perform a variety of biological functions ranging across electron transfer, acid-base catalysis, and sensing where they are agents for cell regulation through transcription (DNA) or translation (RNA). They are redox catalysts for radical-based reactions and the activation of H{sub 2}, N{sub 2} and CO{sub 2}, processes that offer scientific and economic challenges for industry. Iron-sulfur centers provide the focus for fundamental investigations of chemical bonding, spectroscopy and paramagnetism, and their functions have numerous implications for health and medicine and applications for technology, including renewable energy. The 2010 Iron-Sulfur Enzymes GRC will bring together researchers from different disciplines for in-depth discussions and presentations of the latest developments. There will …
Date: June 11, 2010
Creator: Gray, Nancy Ryan
System: The UNT Digital Library
2010 MULTIPHOTON PROCESSES GORDON RESEARCH CONFERENCE, JUNE 6-11, 2010, TILTON, NH (open access)

2010 MULTIPHOTON PROCESSES GORDON RESEARCH CONFERENCE, JUNE 6-11, 2010, TILTON, NH

The Gordon Research Conference on Multiphoton Processes will be held for the 15th time in 2010. The meeting continues to evolve as it embraces both the rapid technological and intellectual growth in the field as well as the multi-disciplinary expertise of the participants. This time the sessions will focus on: (1) Ultrafast coherent control; (2) Free-electron laser experiments and theory; (3) Generation of harmonics and attosecond pulses; (4) Ultrafast imaging; (5) Applications of very high intensity laser fields; (6) Strong-field processes in molecules and solids; (7) Attosecond science; and (8) Controlling light. The scientific program will blur traditional disciplinary boundaries as the presenters and discussion leaders involve chemists, physicists, and optical engineers, representing both experiment and theory. The broad range of expertise and different perspectives of attendees should provide a stimulating and unique environment for solving problems and developing new ideas in this rapidly evolving field.
Date: June 11, 2010
Creator: Gaarde, Mette
System: The UNT Digital Library
2011 Chemical Reactions at Surfaces Gordon Research Conference (open access)

2011 Chemical Reactions at Surfaces Gordon Research Conference

The Gordon Research Conference on Chemical Reactions at Surfaces is dedicated to promoting and advancing the fundamental science of interfacial chemistry and physics by providing surface scientists with the foremost venue for presentation and discussion of research occurring at the frontiers of their fields.
Date: February 11, 2011
Creator: Stair, Peter
System: The UNT Digital Library
2011 Community Earth System Model (CESM) Tutorial, August 1-5, 2011 (open access)

2011 Community Earth System Model (CESM) Tutorial, August 1-5, 2011

In fiscal year 2011, the Community Earth System Model (CESM) tutorial was taught at NCAR from 1-5 August 2011. This project hosted 79 full participants (1 accepted participant from China couldn't get a visa) selected from 180 applications. The tutorial was advertised through emails to CESM mailing lists. NCAR staff and long-term visitors (who were not eligible to attend) were also invited to 'audit' the climate and practical lectures and to work on the practical sessions on their own. 15 NCAR staff and long-term visitors took advantage of this opportunity. The majority of the students were graduate students, but several post-docs, faculty, and other research scientists also attended. Additionally, many people are using the on-line lessons and practical sessions. As of August 18, 2011, 407 people had registered to access and use the tutorial from 33 countries all over the world, but a majority from US universities. In fiscal year 2011, the Climate and Global Dynamics Division Information Systems Group (CGD/ISG) built and operated a temporary computer laboratory in a meeting room. This project was made possible through funding from the National Science Foundation Directorate of Geosciences, and the Department of Energy Office of Science.
Date: October 11, 2013
Creator: Hurrell, James W.
System: The UNT Digital Library
22X mask cleaning effects on EUV lithography process and lifetime (open access)

22X mask cleaning effects on EUV lithography process and lifetime

For this paper, we evaluated the impact of repetitive cleans on a photomask that was fabricated and patterned for extreme ultraviolet lithography exposure. The lithographic performance of the cleaned mask, in terms of process window and line edge roughness, was monitored with the SEMATECH Berkeley micro-exposure tool (MET). Each process measurement of the cleaned mask was compared to a reference mask with the same mask architecture. Both masks were imaged on the same day in order to eliminate any process-related measurement uncertainties. The cleaned mask was periodically monitored with atomic force microscopy (AFM) measurements and pattern widths were monitored using scanning electron microscopy (SEM). In addition, reflectivity changes were also tracked with the aid of witness plate measurements. At the conclusion of this study, the mask under evaluation was cleaned 22 times; with none of the evaluation techniques showing any significant degradation in performance.
Date: March 11, 2011
Creator: George, Simi A.; Chen, Robert J.; Baclea-an, Lorie Mae & Naulleau, Patrick P.
System: The UNT Digital Library
3D Mapping of Polymer Crosslink Density with Magnetic Resonance Imaging (open access)

3D Mapping of Polymer Crosslink Density with Magnetic Resonance Imaging

Magnetic Resonance Imaging (MRI) techniques have been used to detect areas of low crosslink density in damaged silicone parts in an effort to develop a QA/QC protocol to be used in the development of new parts. Model materials of varying crosslink density first demonstrated the applicability of the method. Analysis of damaged pads has been shown to be clearly distinguishable by MRI. It is our belief that both the T{sub 2} weighted SPI NMR and the T{sub 2} weighted water/fat suppression MRI experiments can be used to map out the location of different cross-linking densities, ultimately determining the quality or homogeneity in polymers.
Date: March 11, 2005
Creator: Herberg, J L; Gjersing, E L; Chinn, S C & Maxwell, R S
System: The UNT Digital Library
48Ti(n,xnypz ag) reactions for neutron energies up to 250 MeV (open access)

48Ti(n,xnypz ag) reactions for neutron energies up to 250 MeV

Cross section measurements were made of prompt {gamma}-ray production as a function of incident neutron energy on a {sup 48}Ti sample. Partial {gamma}-ray cross sections for transitions in {sup 45--48}Ti, {sup 44--48}Sc, {sup 42--45}Ca, {sup 41--44}K, and {sup 41--42}Ar have been determined. Energetic neutrons were delivered by the Los Alamos National Laboratory spallation neutron source located at the LANSCE/WNR facility. The prompt-reaction {gamma} rays were detected with the large-scale Compton-suppressed germanium array for neutron induced excitations (GEANIE). Neutron energies were determined by the time-of-flight technique. The {gamma}-ray excitation functions were converted to partial {gamma}-ray cross sections taking into account the dead-time correction, target thickness, detector efficiency and neutron flux (monitored with an in-line fission chamber). The data will be presented for neutron energies between 1 to 250 MeV. These results are compared with model calculations which include compound nuclear and pre-equilibrium emission.
Date: October 11, 2004
Creator: Dashdorj, D.; Garrett, P. E.; Becker, J. A.; Bernstein, L. A.; Cooper, J. R.; Devlin, M. et al.
System: The UNT Digital Library
Ab Initio Large-Basis No-Core Shell Model (open access)

Ab Initio Large-Basis No-Core Shell Model

We discuss the motivation, theory, and formulation of the ab initio No-Core Shell Model (NCSM). In this method the effective Hamiltonians are derived microscopically from realistic nucleon-nucleon (NN) and theoretical three-nucleon (NNN) potentials, as a function of the finite harmonic-oscillator (HO) basis space. We present converged results for the A = 3 and 4 nucleon systems, which are in agreement with results obtained by other exact methods, followed by results for p-shell nuclei. Binding energies, rms radii, excitation spectra, and electromagnetic properties are discussed.The favorable comparison with available data is a consequence of the underlying NN and NNN interactions rather than a phenomenological fit.
Date: February 11, 2005
Creator: Barrett, B R; Navratil, P; Nogga, A; Ormand, W E; Stetcu, I; Vary, J P et al.
System: The UNT Digital Library
Ab Initio No-Core Shell Model (open access)

Ab Initio No-Core Shell Model

A long-standing goal of nuclear theory is to determine the properties of atomic nuclei based on the fundamental interactions among the protons and neutrons (i.e., nucleons). By adopting nucleon-nucleon (NN), three-nucleon (NNN) and higher-nucleon interactions determined from either meson-exchange theory or QCD, with couplings fixed by few-body systems, we preserve the predictive power of nuclear theory. This foundation enables tests of nature's fundamental symmetries and offers new vistas for the full range of complex nuclear phenomena. Basic questions that drive our quest for a microscopic predictive theory of nuclear phenomena include: (1) What controls nuclear saturation; (2) How the nuclear shell model emerges from the underlying theory; (3) What are the properties of nuclei with extreme neutron/proton ratios; (4) Can we predict useful cross sections that cannot be measured; (5) Can nuclei provide precision tests of the fundamental laws of nature; and (6) Under what conditions do we need QCD to describe nuclear structure, among others. Along with other ab initio nuclear theory groups, we have pursued these questions with meson-theoretical NN interactions, such as CD-Bonn and Argonne V18, that were tuned to provide high-quality descriptions of the NN scattering phase shifts and deuteron properties. We then add meson-theoretic NNN …
Date: April 11, 2011
Creator: Barrett, B R; Navratil, P & Vary, J P
System: The UNT Digital Library
Ab Initio Simulation of Materials under Extreme Conditions (open access)

Ab Initio Simulation of Materials under Extreme Conditions

The study of materials properties under extreme conditions has made considerable progress over the past decade due to both improvements in experimental techniques and advanced modeling methods. The availability of accurate models is crucial in order to analyze experimental results obtained in extreme conditions of pressure and temperature where experimental data can be scarce. Among theoretical models, ab initio simulations are playing an increasingly important role due to their ability to predict materials properties without the need for any experimental input. Ab initio simulations also allow for an exploration of materials properties in conditions that are unachievable using controlled experiments--such as e.g. the conditions prevailing in the core of large planets. In that limit, they constitute the only quantitative model of condensed matter available today. In this article, we review the current status of ab initio simulations and discuss examples of recent applications in which numerical simulations have provided an essential complement to experimental data.
Date: August 11, 2005
Creator: Gygi, F. & Galli, G.
System: The UNT Digital Library
Absolute band alignment at semiconductor-water interfaces using explicit and implicit descriptions for liquid water (open access)

Absolute band alignment at semiconductor-water interfaces using explicit and implicit descriptions for liquid water

Article presents a rigorous and systematic study of the band alignment of semiconductors in aqueous solutions by contrasting a range of hybrid explicit/implicit models against explicit atomistic simulations based on density-functional theory.
Date: October 11, 2019
Creator: Hörmann, Nicolas; Guo, Zhendong; Ambrosio, Francesco; Andreussi, Oliviero; Pasquarello, Alfredo & Marzari, Nicola
System: The UNT Digital Library
Absorber height effects on SWA restrictions and 'Shadow' LER (open access)

Absorber height effects on SWA restrictions and 'Shadow' LER

None
Date: March 11, 2011
Creator: McClinton, Brittany M.; Naulleau, Patrick P. & Wallow, Thomas
System: The UNT Digital Library
Absorption Spectra of Broadened Sodium Resonance Lines in Presence of Rare Gases (open access)

Absorption Spectra of Broadened Sodium Resonance Lines in Presence of Rare Gases

The pressure broadening of alkali-metal lines is a fundamental problem with numerous applications. For example, the sodium resonance lines broadened by xenon are important in the production of broad spectra emitted in the HPS (High-Pressure Sodium) lamp and they potentially can be used for gas condition diagnostics. Broadened absorption lines of alkali-metal atoms are prominent in the optical spectra of brown dwarfs and understanding the broadening mechanism will help elucidate the chemical composition and atmospheric properties of those stars. The far-line wing spectra of sodium resonance lines broadened by rare gases are found to exhibit molecular characteristics such as satellites and hence the total absorption coefficients for vapors of Na atoms and perturbing rare gas atoms can be modeled as Na-RG (rare gas) molecular absorption spectra. In this work, using carefully chosen interatomic potentials for Na-RG molecules we carry out quantum-mechanical calculations for reduced absorption coefficients for vapors composed of Na-He, Na-Ar, and Na-Xe. Calculated spectra are compared to available experimental results and the agreement is good in the measured satellite positions and shapes.
Date: September 11, 2002
Creator: Chung, H-K; Shurgalin, M & Babb, J F
System: The UNT Digital Library
Accelerated alpha radiation damage in a ceramic waste form, interim results (open access)

Accelerated alpha radiation damage in a ceramic waste form, interim results

Interim results are presented on the alpha-decay damage study of a {sup 238}Pu-loaded ceramic waste form (CWF). The waste form was developed to immobilize fission products and transuranic species accumulated from the electrometallurgical treatment of spent nuclear fuel. To evaluate the effects of {alpha}-decay damage on the waste form the {sup 238}Pu-loaded material was analyzed by (1) x-ray diffraction (XRD), (2) microstructure characterization by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) with energy and wavelength dispersive spectroscopy (EDS/WDS) and electron diffraction, (3) bulk density measurements and (4) waste form durability, performed by the product consistency test (PCT). While the predominate phase of plutonium in the CWF, PuO{sub 2}, shows the expected unit cell expansion due to {alpha}-decay damage, currently no significant change has occurred to the macro- or microstructure of the material. The major phase of the waste form is sodalite and contains very little Pu, although the exact amount is unknown. Interestingly, measurement of the sodalite phase unit cell is also showing very slight expansion; again, presumably from {alpha}-decay damage.
Date: November 11, 1999
Creator: Frank, S. M.; Johnson, S. G.; Moschetti, T. L.; O'Holleran, T. P.; Sinkler, W.; Esh, D. et al.
System: The UNT Digital Library
Acceleration of compact toruses and fusion applications (open access)

Acceleration of compact toruses and fusion applications

The Compact Torus (Spheromak-type) is a near ideal plasma confinement configuration for acceleration. The fields are mostly generated by internal plasma currents, plasma confinement is toroidal, and the compact torus exhibits resiliency and stability in virtue of the ``rugged`` helicity invariant. Based on these considerations we are developing a coaxial rail-gun type Compact Torus Accelerator (CTA). In the CTA, the CT ring is formed between coaxial electrodes using a magnetized Marshall gun, it is quasistatically ``precompressed`` in a conical electrode section for inductive energy storage, it is accelerated in a straight-coaxial electrode section as in a conventional rail-gun, and it is focused to small size and high energy and power density in a final ``focus`` cone section. The dynamics of slow precompression and acceleration have been demonstrated experimentally in the RACE device with results in good agreement with 2-D MHD code calculations. CT plasma rings with 100 {micro}gms mass have been accelerated to 40 Kj kinetic energy at 20% efficiency with final velocity = 1 X 10{sup 8} cm/s (= 5 KeV/H{sup +}). Preliminary focus tests exhibi dynamics of radius compression, deceleration, and bouncing. Compression ratios of 2-3 have been achieved. A scaled-up 10-100 MJ CTA is predicted to achieve …
Date: October 11, 1990
Creator: Hartman, C. W.; Eddleman, J. L.; Hammer, J. H.; Logan, B. G.; McLean, H. S. & Molvik, A. W.
System: The UNT Digital Library
Accelerators for Intensity Frontier Research (open access)

Accelerators for Intensity Frontier Research

In 2008, the Particle Physics Project Prioritization Panel identified three frontiers for research in high energy physics, the Energy Frontier, the Intensity Frontier, and the Cosmic Frontier. In this paper, I will describe how Fermilab is configuring and upgrading the accelerator complex, prior to the development of Project X, in support of the Intensity Frontier.
Date: May 11, 2012
Creator: Derwent, Paul
System: The UNT Digital Library
Activation of apoptosis in NAF-1-deficient human epithelial breast cancer cells (open access)

Activation of apoptosis in NAF-1-deficient human epithelial breast cancer cells

This article shows that small hairpin RNA-mediated suppresion of NAF-1 results in the activation of apoptosis in epithelial breast cancer cells and xenograft tumors.
Date: November 11, 2015
Creator: Holt, Sarah H.; Darash-Yahana, Merav; Sohn, Yang Sung; Song, Luhua; Karmi, Ola; Tamir, Sagi et al.
System: The UNT Digital Library
An Active Region Model for Capturing Fractal Flow Patterns inUnsaturated Soils: Model Development (open access)

An Active Region Model for Capturing Fractal Flow Patterns inUnsaturated Soils: Model Development

Preferential flow commonly observed in unsaturated soils allows rapid movement of solute from the soil surface or vadose zone to the groundwater, bypassing a significant volume of unsaturated soil and increasing the risk of groundwater contamination. A variety of evidence indicates that complex preferential patterns observed from fields are fractals. In this study, we developed a relatively simple active region model to incorporate the fractal flow pattern into the continuum approach. In the model, the flow domain is divided into active and inactive regions. Flow occurs preferentially in the active region (characterized by fractals), and inactive region is simply bypassed. A new constitutive relationship (the portion of the active region as a function of saturation) was derived. The validity of the proposed model is demonstrated by the consistency between field observations and the new constitutive relationship.
Date: June 11, 2005
Creator: Liu, Hui-Hai; Zhang, R. & Bodvarsson, Gudmundur S.
System: The UNT Digital Library