Two-dimensional Vortex Behavior in Highly Underdoped YBa_2Cu_3O_{6+x} Observed byScanning Hall Probe Microscopy (open access)

Two-dimensional Vortex Behavior in Highly Underdoped YBa_2Cu_3O_{6+x} Observed byScanning Hall Probe Microscopy

We report scanning Hall probe microscopy of highly underdoped superconducting YBa{sub 2}Cu{sub 3}O{sub 6+z} with T{sub c} ranging from 5 to 15 K which showed distinct flux bundles with less than one superconducting flux quantum ({Phi}{sub 0}) through the sample surface. The sub-{Phi}{sub 0} features occurred more frequently for lower T{sub c}, were more mobile than conventional vortices, and occurred more readily when the sample was cooled with an in-plane field component. We show that these features are consistent with kinked stacks of pancake vortices.
Date: April 22, 2008
Creator: Guikema, J.W.; Bluhm, Hendrik; /Stanford U., Appl. Phys. Dept.; Bonn, D.A.; Liang, Ruixing; Hardy, W.N. et al.
Object Type: Article
System: The UNT Digital Library
Dynamic versus Static Structure Functions and Novel Diffractive Effects in QCD (open access)

Dynamic versus Static Structure Functions and Novel Diffractive Effects in QCD

Initial- and final-state rescattering, neglected in the parton model, have a profound effect in QCD hard-scattering reactions, predicting single-spin asymmetries, diffractive deep inelastic scattering, diffractive hard hadronic reactions, the breakdown of the Lam Tung relation in Drell-Yan reactions, and nuclear shadowing and non-universal antishadowing--leading-twist physics not incorporated in the light-front wavefunctions of the target computed in isolation. I also discuss the use of diffraction to materialize the Fock states of a hadronic projectile and test QCD color transparency, and anomalous heavy quark effects. The presence of direct higher-twist processes where a proton is produced in the hard subprocess can explain the large proton-to-pion ratio seen in high centrality heavy ion collisions. I emphasize the importance of distinguishing between static observables such as the probability distributions computed from the square of the light-front wavefunctions versus dynamical observables which include the effects of rescattering.
Date: November 12, 2008
Creator: Brodsky, Stanley J.
Object Type: Article
System: The UNT Digital Library
The EMMA Main Ring Lattice. (open access)

The EMMA Main Ring Lattice.

I give a brief introduction to the purpose and goals of the EMMA experiment and describe how they will impact the design of the main EMMA ring. I then describe the mathematical model that is used to describe the EMMA lattice. Finally, I show how the different lattice configurations were obtained and list their parameters.
Date: February 21, 2008
Creator: Berg, J. S.
Object Type: Report
System: The UNT Digital Library
VERTIGO (VERtical Transport In the Global Ocean): A study of particle sources and flux attenuation in the North Pacific (open access)

VERTIGO (VERtical Transport In the Global Ocean): A study of particle sources and flux attenuation in the North Pacific

The VERtical Transport In the Global Ocean (VERTIGO) study examined particle sources and fluxes through the ocean's 'twilight zone' (defined here as depths below the euphotic zone to 1000 m). Interdisciplinary process studies were conducted at contrasting sites off Hawaii (ALOHA) and in the NW Pacific (K2) during 3 week occupations in 2004 and 2005, respectively. We examine in this overview paper the contrasting physical, chemical and biological settings and how these conditions impact the source characteristics of the sinking material and the transport efficiency through the twilight zone. A major finding in VERTIGO is the considerably lower transfer efficiency (T{sub eff}) of particulate organic carbon (POC), POC flux 500/150 m, at ALOHA (20%) vs. K2 (50%). This efficiency is higher in the diatom-dominated setting at K2 where silica-rich particles dominate the flux at the end of a diatom bloom, and where zooplankton and their pellets are larger. At K2, the drawdown of macronutrients is used to assess export and suggests that shallow remineralization above our 150 m trap is significant, especially for N relative to Si. We explore here also surface export ratios (POC flux/primary production) and possible reasons why this ratio is higher at K2, especially during the …
Date: June 10, 2008
Creator: Buesseler, K. O.; Trull, T. W.; Steinberg, D. K.; Silver, M. W.; Siegel, D. A.; Saitoh, S. I. et al.
Object Type: Article
System: The UNT Digital Library
Particulate matter chemistry and dynamics in the Twilight Zone at VERTIGO ALOHA and K2 Sites (open access)

Particulate matter chemistry and dynamics in the Twilight Zone at VERTIGO ALOHA and K2 Sites

Understanding particle dynamics in the 'Twilight Zone' is critical to prediction of the ocean's carbon cycle. As part of the VERTIGO (VERtical Transformations In the Global Ocean) project, this rarely sampled regime extending from the base of the euphotic layer to 1000 m, was characterized by double-paired day/night Multiple Unit Large Volume in-situ Filtration System (MULVFS) deployments and by {approx}100 high-frequency CTD/transmissometer/turbidity sensor profiles. VERTIGO studies lasting three weeks, contrasted oligotrophic station ALOHA (22.75{sup o}N 158{sup o}W), sampled in June-July 2004, with a biologically productive location (47{sup o}N 161{sup o}E) near station K2 in the Oyashio, occupied July-August 2005. Profiles of major and minor particulate components (C{sub org}, N, P, Ca, Si, Sr, Ba, Mn) in <1, 1-51, and >51 {micro}m size fractions, in-water optics, neutrally buoyant sediment trap (NBST) fluxes, and zooplankton data were intercompared. MULVFS total C{sub org} and C-Star particle beam attenuation coefficient (C{sub P}) were consistently related at both sites with a 27 {micro}M m{sup -1} conversion factor. 26 At K2, C{sub P} profiles further showed a multitude of transient spikes throughout the water column and spike abundance profiles closely paralleled the double peaked abundance profiles of zooplankton. Also at K2, copepods contributed {approx}40% and 10%, …
Date: March 25, 2008
Creator: Bishop, James K.B. & Wood, T.J.
Object Type: Article
System: The UNT Digital Library
A Review of the Reflector Compact Fluorescent Lights Technology Procurement Program: Conclusions and Results (open access)

A Review of the Reflector Compact Fluorescent Lights Technology Procurement Program: Conclusions and Results

This report describes a project sponsored by the U.S. Department of Energy (DOE) and implemented by the Pacific Northwest National Laboratory (PNNL), from 2000 to 2007 to improve the performance of reflector type (R-lamp) compact fluorescent lamps (CFLs) and increase their availability throughout the United States by means of a technology development and procurement strategy. In 2000, at the request of the U.S. Department of Energy’s Emerging Technologies Program and its predecessors, the Pacific Northwest National Laboratory undertook a technology procurement seeking R-CFLs that were specifically designed for use in ICAT recessed can fixtures and that met other minimum performance criteria including minimum light output and size restrictions (to ensure they fit in standard residential recessed cans). The technology procurement included two phases. In Phase I, requests for proposals (RFPs) were issued in October 2002 and five manufacturers responded with 12 lamp models. Eight of these models met the minimum requirements and passed the 6-hour short-term test in a simulated ICAT environment. These eight models were subjected to long-term tests of 6,000 or more hours in a simulated ICAT environment. Three of these models passed the short- and long-term tests and were promoted through the program website (www.pnl.gov/rlamps), press releases, …
Date: May 19, 2008
Creator: Sandahl, Linda J.; Gilbride, Theresa L.; Ledbetter, Marc R. & McCullough, Jeffrey J.
Object Type: Report
System: The UNT Digital Library
Polychlorinated Biphenyls (PCBs) in Catfish and Carp Collected from the Rio Grande Upstream and Downstream of Los Alamos National Laboratory: Revision 1 (open access)

Polychlorinated Biphenyls (PCBs) in Catfish and Carp Collected from the Rio Grande Upstream and Downstream of Los Alamos National Laboratory: Revision 1

Concern has existed for years that the Los Alamos National Laboratory (LANL), a complex of nuclear weapons research and support facilities, has released polychlorinated biphenyls (PCBs) to the environment that may have reached adjacent bodies of water through canyons that connect them. In 1997, LANL's Ecology Group began measuring PCBs in fish in the Rio Grande upstream and downstream of ephemeral streams that cross LANL and later began sampling fish in Abiquiu and Cochiti reservoirs, which are situated on the Rio Chama and Rio Grande upstream and downstream of LANL, respectively. In 2002, we electroshocked channel catfish (Ictalurus punctatus) and common carp (Carpiodes carpio) in the Rio Grande upstream and downstream of LANL and analyzed fillets for PCB congeners. We also sampled soils along the Rio Chama and Rio Grande drainages to discern whether a background atmospheric source of PCBs that could impact surface water adjacent to LANL might exist. Trace concentrations of PCBs measured in soil (mean = 4.7E-05 {micro}g/g-ww) appear to be from background global atmospheric sources, at least in part, because the bimodal distribution of low-chlorinated PCB congeners and mid-chlorinated PCB congeners in the soil samples is interpreted to be typical of volatilized PCB congeners that are …
Date: May 12, 2008
Creator: Fresquez, Gilbert J. Gonzales Philip R.
Object Type: Report
System: The UNT Digital Library
Extracellular matrix control of mammary gland morphogenesis and tumorigenesis: insights from imaging (open access)

Extracellular matrix control of mammary gland morphogenesis and tumorigenesis: insights from imaging

The extracellular matrix (ECM), once thought to solely provide physical support to a tissue, is a key component of a cell's microenvironment responsible for directing cell fate and maintaining tissue specificity. It stands to reason, then, that changes in the ECM itself or in how signals from the ECM are presented to or interpreted by cells can disrupt tissue organization; the latter is a necessary step for malignant progression. In this review, we elaborate on this concept using the mammary gland as an example. We describe how the ECM directs mammary gland formation and function, and discuss how a cell's inability to interpret these signals - whether as a result of genetic insults or physicochemical alterations in the ECM - disorganizes the gland and promotes malignancy. By restoring context and forcing cells to properly interpret these native signals, aberrant behavior can be quelled and organization re-established. Traditional imaging approaches have been a key complement to the standard biochemical, molecular, and cell biology approaches used in these studies. Utilizing imaging modalities with enhanced spatial resolution in live tissues may uncover additional means by which the ECM regulates tissue structure, on different length scales, through its pericellular organization (short-scale) and by biasing …
Date: October 23, 2008
Creator: Ghajar, Cyrus M & Bissell, Mina J
Object Type: Article
System: The UNT Digital Library
Materials Science and Technology Teachers Handbook (open access)

Materials Science and Technology Teachers Handbook

The Materials Science and Technology (MST) Handbook was developed by Pacific Northwest National Laboratory, in Richland, Washington, under support from the U.S. Department of Energy. Many individuals have been involved in writing and reviewing materials for this project since it began at Richland High School in 1986, including contributions from educators at the Northwest Regional Education Laboratory, Central Washington University, the University of Washington, teachers from Northwest Schools, and science and education personnel at Pacific Northwest National Laboratory. Support for its development was also provided by the U.S. Department of Education. This introductory course combines the academic disciplines of chemistry, physics, and engineering to create a materials science and technology curriculum. The course covers the fundamentals of ceramics, glass, metals, polymers and composites. Designed to appeal to a broad range of students, the course combines hands-on activities, demonstrations and long term student project descriptions. The basic philosophy of the course is for students to observe, experiment, record, question, seek additional information, and, through creative and insightful thinking, solve problems related to materials science and technology. The MST Teacher Handbook contains a course description, philosophy, student learning objectives, and instructional approach and processes. Science and technology teachers can collaborate to build …
Date: September 4, 2008
Creator: Wieda, Karen J.; Schweiger, Michael J.; Bliss, Mary; Pitman, Stan G. & Eschbach, Eugene A.
Object Type: Report
System: The UNT Digital Library
Novel QCD Phenomena at Electron-Proton Colliders (open access)

Novel QCD Phenomena at Electron-Proton Colliders

I discuss several novel phenomenological features of QCD which are observable in deep inelastic lepton-nucleon and lepton-nucleus scattering. Initial- and final-state interactions from gluon exchange, normally neglected in the parton model, have a profound effect on QCD hard-scattering reactions, leading to leading-twist single-spin asymmetries, the diffractive contribution to deep inelastic scattering, and the breakdown of the pQCD Lam-Tung relation in Drell-Yan reactions. Leading-twist diffractive processes in turn lead to nuclear shadowing and non-universal antishadowing--physics not incorporated in the light-front wavefunctions of the nucleus computed in isolation.
Date: July 25, 2008
Creator: Brodsky, Stanley J. & /SLAC /Durham U., IPPP
Object Type: Article
System: The UNT Digital Library
Tissue architecture and function: dynamic reciprocity via extra- and intra-cellular matrices (open access)

Tissue architecture and function: dynamic reciprocity via extra- and intra-cellular matrices

Mammary gland development, functional differentiation, and homeostasis are orchestrated and sustained by a balance of biochemical and biophysical cues from the organ's microenvironment. The three-dimensional microenvironment of the mammary gland, predominantly 'encoded' by a collaboration between the extracellular matrix (ECM), hormones, and growth factors, sends signals from ECM receptors through the cytoskeletal intracellular matrix to nuclear and chromatin structures resulting in gene expression; the ECM in turn is regulated and remodeled by signals from the nucleus. In this chapter, we discuss how coordinated ECM deposition and remodeling is necessary for mammary gland development, how the ECM provides structural and biochemical cues necessary for tissue-specific function, and the role of the cytoskeleton in mediating the extra - to intracellular dialogue occurring between the nucleus and the microenvironment. When operating normally, the cytoskeletal-mediated dynamic and reciprocal integration of tissue architecture and function directs mammary gland development, tissue polarity, and ultimately, tissue-specific gene expression. Cancer occurs when these dynamic interactions go awry for an extended time.
Date: December 23, 2008
Creator: Xu, Ren; Boudreau, Aaron & Bissell, Mina J
Object Type: Article
System: The UNT Digital Library
Characterization of Vadose Zone Sediment: RCRA Borehole 299-E33-338 Located Near the B-BX-BY Waste Management Area (open access)

Characterization of Vadose Zone Sediment: RCRA Borehole 299-E33-338 Located Near the B-BX-BY Waste Management Area

This report was revised in September 2008 to remove acid-extractable sodium data from Table 4.8. The sodium data was removed due to potential contamination introduced during the acid extraction process. The rest of the text remains unchanged from the original report issued in June 2003. The overall goals of the of the Tank Farm Vadose Zone Project, led by CH2M HILL Hanford Group, Inc., are: 1) to define risks from past and future single-shell tank farm activities, 2) to identify and evaluate the efficacy of interim measures, and 3) to aid via collection of geotechnical information and data, future decisions that must be made by the U.S. Department of Energy (DOE) regarding the near-term operations, future waste retrieval, and final closure activities for the single-shell tank waste management areas. For a more complete discussion of the goals of the Tank Farm Vadose Zone Project, see the overall work plan, Phase 1 RCRA Facility Investigation/Corrective Measures Study Work Plan for the Single-Shell Tank Waste Management Areas (DOE 1999). Specific details on the rationale for activities performed at the B-BX-BY tank farm waste management area are found in CH2M HILL (2000).
Date: September 11, 2008
Creator: Lindenmeier, Clark W.; Serne, R. Jeffrey; Bjornstad, Bruce N.; Gee, Glendon W.; Schaef, Herbert T.; Lanigan, David C. et al.
Object Type: Report
System: The UNT Digital Library
Characterization of Vadose Zone Sediment: Borehole 299-E33-46 Near B 110 in the B BX-BY Waste Management Area (open access)

Characterization of Vadose Zone Sediment: Borehole 299-E33-46 Near B 110 in the B BX-BY Waste Management Area

This report was revised in September 2008 to remove acid-ectractable sodium data from Table 4.17. The sodium data was removed due to potential contamination introduced during the acid extraction process. The rest of the text remains unchanged from the original report issued in December 2002. The overall goal of the of the Tank Farm Vadose Zone Project, led by CH2M HILL Hanford Group, Inc., is to define risks from past and future single-shell tank farm activities. To meet this goal, CH2M HILL Hanford Group, Inc., asked scientists from Pacific Northwest National Laboratory to perform detailed analyses on vadose zone sediment from within the B-BX-BY Waste Management Area. This report is the third in a series of three reports to present the results of these analyses. Specifically, this report contains all the geologic, geochemical, and selected physical characterization data collected on vadose zone sediment recovered from a borehole installed approximately 4.5 m (15 ft) northeast of tank B- 110 (borehole 299-E33-46).
Date: September 11, 2008
Creator: Serne, R. Jeffrey; Bjornstad, Bruce N.; Gee, Glendon W.; Schaef, Herbert T.; Lanigan, David C.; Mccain, R. G. et al.
Object Type: Report
System: The UNT Digital Library
NCSX Plasma Heating Methods (open access)

NCSX Plasma Heating Methods

The National Compact Stellarator Experiment (NCSX) has been designed to accommodate a variety of heating systems, including ohmic heating, neutral beam injection, and radio-frequency (rf). Neutral beams will provide one of the primary heating methods for NCSX. In addition to plasma heating, neutral beams are also expected to provide a means for external control over the level of toroidal plasma rotation velocity and its profile. The experimental plan requires 3 MW of 50-keV balanced neutral beam tangential injection with pulse lengths of 500 ms for initial experiments, to be upgradeable to pulse lengths of 1.5 s. Subsequent upgrades will add 3MW of neutral beam injection (NBI). This paper discusses the NCSX NBI requirements and design issues and shows how these are provided by the candidate PBX-M NBI system. In addition, estimations are given for beam heating efficiencies, scaling of heating efficiency with machine size and magnetic field level, parameter studies of the optimum beam injection tangency radius and toroidal injection location, and loss patterns of beam ions on the vacuum chamber wall to assist placement of wall armor and for minimizing the generation of impurities by the energetic beam ions. Finally, subsequent upgrades could add an additional 6 MW of …
Date: January 18, 2008
Creator: H.W. Kugel, D. Spong, R. Majeski and M. Zarnstorff
Object Type: Report
System: The UNT Digital Library
Long-Term Monitoring at the East and West Flower Garden Banks, 2004-2005 -- Interim Report, Volume 1: Technical Report (open access)

Long-Term Monitoring at the East and West Flower Garden Banks, 2004-2005 -- Interim Report, Volume 1: Technical Report

A report documenting the monitoring of the East and West Flower Garden Banks in accordance with the long-term monitoring protocol.
Date: June 2008
Creator: Precht, William F.; Aronson, Richard B.; Deslarzes, Kenneth J. P.; Robbart, Martha L.; Evans, David J.; Zimmer, Beth et al.
Object Type: Text
System: The UNT Digital Library
Three-dimensional lithographically-defined organotypic tissue arrays for quantitative analysis of morphogenesis and neoplastic progression (open access)

Three-dimensional lithographically-defined organotypic tissue arrays for quantitative analysis of morphogenesis and neoplastic progression

Here we describe a simple micromolding method to construct three-dimensional arrays of organotypic epithelial tissue structures that approximate in vivo histology. An elastomeric stamp containing an array of posts of defined geometry and spacing is used to mold microscale cavities into the surface of type I collagen gels. Epithelial cells are seeded into the cavities and covered with a second layer of collagen. The cells reorganize into hollow tissues corresponding to the geometry of the cavities. Patterned tissue arrays can be produced in 3-4 h and will undergo morphogenesis over the following one to three days. The protocol can easily be adapted to study a variety of tissues and aspects of normal and neoplastic development.
Date: February 13, 2008
Creator: Nelson, Celeste M.; Inman, Jamie L. & Bissell, Mina J.
Object Type: Article
System: The UNT Digital Library
Modeled Neutron Induced Nuclear Reaction Cross Sections for Radiochemistry in the region of Iriduim and Gold (open access)

Modeled Neutron Induced Nuclear Reaction Cross Sections for Radiochemistry in the region of Iriduim and Gold

We have developed a set of modeled nuclear reaction cross sections for use in radiochemical diagnostics. Systematics for the input parameters required by the Hauser-Feshbach statistical model were developed and used to calculate neutron induced nuclear reaction cross sections for targets ranging from osmium (Z = 76) to gold (Z = 79). Of particular interest are the cross sections on Ir and Au including reactions on isomeric targets.
Date: February 26, 2008
Creator: Hoffman, R. D.; Dietrich, F. S.; Kelley, K.; Escher, J.; Bauer, R. & Mustafa, M. G.
Object Type: Report
System: The UNT Digital Library
Analysis of intensity instability threshold at transition in RHIC. (open access)

Analysis of intensity instability threshold at transition in RHIC.

The beam intensity of ion beams in RHIC is limited by a fast transverse instability at transition, driven by the machine impedance and electron clouds. For gold and deuteron beams we analyze the dependence of the instability threshold on beam and machine parameters from recent operational data and dedicated experiments. We fit the machine impedance to the experimental data.
Date: June 23, 2008
Creator: Fischer, W.; Blaskiewicz, M.; Cameron, P.; Montag, C. & Ptitsyn, V.
Object Type: Article
System: The UNT Digital Library
Rapid Formation of Supermassive Black Hole Binaries in Galaxy Mergers with Gas (open access)

Rapid Formation of Supermassive Black Hole Binaries in Galaxy Mergers with Gas

Supermassive black holes (SMBHs) are a ubiquitous component of the nuclei of galaxies. It is normally assumed that, following the merger of two massive galaxies, a SMBH binary will form, shrink due to stellar or gas dynamical processes and ultimately coalesce by emitting a burst of gravitational waves. However, so far it has not been possible to show how two SMBHs bind during a galaxy merger with gas due to the difficulty of modeling a wide range of spatial scales. Here we report hydrodynamical simulations that track the formation of a SMBH binary down to scales of a few light years following the collision between two spiral galaxies. A massive, turbulent nuclear gaseous disk arises as a result of the galaxy merger. The black holes form an eccentric binary in the disk in less than a million years as a result of the gravitational drag from the gas rather than from the stars.
Date: March 24, 2008
Creator: Mayer, L.; Kazantzidis, S.; Madau, P.; Colpi, M.; Quinn, T. & Wadsley, J.
Object Type: Article
System: The UNT Digital Library
Characterization of Vadose Zone Sediment: Borehole 299-E33-45 Near BX-102 in the B-BX-BY Waste Management Area (open access)

Characterization of Vadose Zone Sediment: Borehole 299-E33-45 Near BX-102 in the B-BX-BY Waste Management Area

This report was revised in September 2008 to remove acid-extractable sodium data from Table 4.22. The data was removed due to potential contamination introduced during the acid extraction process. The remaining text is unchanged from the original report issued in 2002. The overall goal of the Tank Farm Vadose Zone Project, led by CH2M HILL Hanford Group, Inc., is to define risks from past and future single-shell tank farm activities. To meet this goal, CH2M HILL Hanford Group, Inc., asked scientists from Pacific Northwest National Laboratory to perform detailed analyses on vadose zone sediments from within Waste Management Area B-BX-BY. This report is the first in a series of four reports to present the results of these analyses. Specifically, this report contains all the geologic, geochemical, and selected physical characterization data collected on vadose zone sediment recovered from borehole 299-E33-45 installed northeast of tank BX-102.
Date: September 11, 2008
Creator: Serne, R. Jeffrey; Last, George V.; Gee, Glendon W.; Schaef, Herbert T.; Lanigan, David C.; Lindenmeier, Clark W. et al.
Object Type: Report
System: The UNT Digital Library
Sludge Mass Reduction: Primary Compositional Factors That Influence Melt Rate for Future Sludge Batch Projections (open access)

Sludge Mass Reduction: Primary Compositional Factors That Influence Melt Rate for Future Sludge Batch Projections

The Savannah River National Laboratory (SRNL) was tasked to provide an assessment of the downstream impacts to the Defense Waste Processing Facility (DWPF) of decisions regarding the implementation of Al-dissolution to support sludge mass reduction and processing. Based on future sludge batch compositional projections from the Liquid Waste Organization's (LWO) sludge batch plan, assessments have been made with respect to the ability to maintain comparable projected operating windows for sludges with and without Al-dissolution. As part of that previous assessment, candidate frits were identified to provide insight into melt rate for average sludge batches representing with and without Al-dissolution flowsheets. Initial melt rate studies using the melt rate furnace (MRF) were performed using five frits each for Cluster 2 and Cluster 4 compositions representing average without and with Al-dissolution. It was determined, however, that the REDOX endpoint (Fe{sup 2+}/{Sigma}Fe for the glass) for Clusters 2 and 4 resulted in an overly oxidized feed which negatively affected the initial melt rate tests. After the sludge was adjusted to a more reduced state, additional testing was performed with frits that contained both high and low concentrations of sodium and boron oxides. These frits were selected strictly based on the ability to ascertain …
Date: August 28, 2008
Creator: Newell, J. D.; Miller, D. H.; Stone, M. E. & Pickenheim, B. R.
Object Type: Report
System: The UNT Digital Library
Center for Gyrokinetic Particle Simulation of Turbulent Transport in Burning Plasma (open access)

Center for Gyrokinetic Particle Simulation of Turbulent Transport in Burning Plasma

The UCLA work on this grant was to design and help implement an object-oriented version of the GTC code, which is written in Fortran90. The GTC code is the main global gyrokinetic code used in this project, and over the years multiple, incompatible versions have evolved. The reason for this effort is to allow multiple authors to work together on GTC and to simplify future enhancements to GTC. The effort was designed to proceed incrementally. Initially, an upper layer of classes (derived types and methods) was implemented which called the original GTC code 'under the hood.' The derived types pointed to data in the original GTC code, and the methods called the original GTC subroutines. The original GTC code was modified only very slightly. This allowed one to define (and refine) a set of classes which described the important features of the GTC code in a new, more abstract way, with a minimum of implementation. Furthermore, classes could be added one at a time, and at the end of the each day, the code continued to work correctly. This work was done in close collaboration with Y. Nishimura from UC Irvine and Stefan Ethier from PPPL. Ten classes were ultimately …
Date: April 24, 2008
Creator: Decyk, Viktor K.
Object Type: Report
System: The UNT Digital Library
An Atomic Gravitational Wave Interferometric Sensor (AGIS) (open access)

An Atomic Gravitational Wave Interferometric Sensor (AGIS)

We propose two distinct atom interferometer gravitational wave detectors, one terrestrial and another satellite-based, utilizing the core technology of the Stanford 10m atom interferometer presently under construction. Each configuration compares two widely separated atom interferometers run using common lasers. The signal scales with the distance between the interferometers, which can be large since only the light travels over this distance, not the atoms. The terrestrial experiment with baseline {approx} 1 km can operate with strain sensitivity {approx} 10{sup -19}/{radical}Hz in the 1 Hz-10 Hz band, inaccessible to LIGO, and can detect gravitational waves from solar mass binaries out to megaparsec distances. The satellite experiment with baseline {approx} 1000 km can probe the same frequency spectrum as LISA with comparable strain sensitivity {approx} 10{sup -20}/{radical}Hz. The use of ballistic atoms (instead of mirrors) as inertial test masses improves systematics coming from vibrations, acceleration noise, and significantly reduces spacecraft control requirements. We analyze the backgrounds in this configuration and discuss methods for controlling them to the required levels.
Date: August 1, 2008
Creator: Dimopoulos, Savas; Graham, Peter W.; Hogan, Jason M.; Kasevich, Mark A. & Rajendran, Surjeet
Object Type: Report
System: The UNT Digital Library
Mesoscale Characterization of Coupled Hydromechanical Behavior of a Fractured Porous Slope in Response to Free Water-Surface Movement (open access)

Mesoscale Characterization of Coupled Hydromechanical Behavior of a Fractured Porous Slope in Response to Free Water-Surface Movement

To better understand the role of groundwater-level changes on rock-slope deformation and damage, a carbonate rock slope (30 m x 30 m x 15 m) was extensively instrumented for mesoscale hydraulic and mechanical measurements during water-level changes. The slope is naturally drained by a spring that can be artificially closed or opened by a water gate. In this study, a 2-hour slope-dewatering experiment was analyzed. Changes in fluid pressure and deformation were simultaneously monitored, both at discontinuities and in the intact rock, using short-base extensometers and pressure gauges as well as tiltmeters fixed at the slope surface. Field data were analyzed with different coupled hydromechanical (HM) codes (ROCMAS, FLAC{sup 3D}, and UDEC). Field data indicate that in the faults, a 40 kPa pressure fall occurs in 2 minutes and induces a 0.5 to 31 x 10{sup -6} m normal closure. Pressure fall is slower in the bedding-planes, lasting 120 minutes with no normal deformation. No pressure change or deformation is observed in the intact rock. The slope surface displays a complex tilt towards the interior of the slope, with magnitudes ranging from 0.6 to 15 x 10{sup -6} rad. Close agreement with model for both slope surface and internal measurements …
Date: May 15, 2008
Creator: Rutqvist, Jonny; Guglielmi, Y.; Cappa, F.; Rutqvist, J.; Tsang, C.-F. & Thoraval, A.
Object Type: Article
System: The UNT Digital Library