Analysis of community structure in networks of correlated data (open access)

Analysis of community structure in networks of correlated data

We present a reformulation of modularity that allows the analysis of the community structure in networks of correlated data. The new modularity preserves the probabilistic semantics of the original definition even when the network is directed, weighted, signed, and has self-loops. This is the most general condition one can find in the study of any network, in particular those defined from correlated data. We apply our results to a real network of correlated data between stores in the city of Lyon (France).
Date: December 25, 2008
Creator: Gomez, S.; Jensen, P. & Arenas, A.
Object Type: Article
System: The UNT Digital Library
A Comparison of Radiating Divertor Behavior in Single- and Double-Null Plasmas in DIII-D (open access)

A Comparison of Radiating Divertor Behavior in Single- and Double-Null Plasmas in DIII-D

'Puff and pump' radiating divertor scenarios, applied to both upper single-null (SN) and double-null (DN) H-mode plasmas, result in a 30-60% increase in radiated power with little or no decrease in {tau}{sub E}. Argon was injected into the private flux region of the upper divertor, and plasma flow into the upper divertor was enhanced by a combination of deuterium gas puffing upstream of the divertor targets and particle pumping at the targets. For the same constant deuterium injection rate, argon penetrated the main plasma of SNs more rapidly and reached a higher steady-state concentration when the Bx{del}B-ion drift direction was toward the divertor (V{sub {del}B{up_arrow}}) rather than away from the divertor (V{sub {del}B{down_arrow}}). We also found that the initial rate at which argon accumulated inside DN plasmas was more than twice that of comparable SN plasmas having the same Bx{del}B-ion drift direction. In DNs, the radiated power was not shared equally between divertors during argon injection. Only in the divertor opposite Bx{del}B ion drift direction were both significant increases in divertor radiated power and an accumulation of argon, based on spectroscopic measurements of ArII, observed. Our data suggests that a DN shape that is biased in the direction away from …
Date: March 25, 2008
Creator: Petrie, T. W.; Brooks, N. H.; Fenstermacher, M. E.; Groth, M.; Hyatt, A. W.; Isler, R. C. et al.
Object Type: Article
System: The UNT Digital Library
Final Implementation Report for the National Defense Authorization Act for Fiscal Year 2008 (open access)

Final Implementation Report for the National Defense Authorization Act for Fiscal Year 2008

This report on the implementation of National Defense Authorization Act (NDAA) for Fiscal Year 2008, section 904 "Management of the Department of Defense," presents the consensus recommendations of the Department's senior management team on the assignment of duties for the Chief Management Office (CMO), the Deputy Chief Management Office, and the Military Department CMO's, as well as summarizing the Department's inaugural Strategic Management Plan.
Date: July 25, 2008
Creator: United States. Department of Defense.
Object Type: Report
System: The UNT Digital Library
ALT-GTS-Stem Fabrication (open access)

ALT-GTS-Stem Fabrication

In 2007, a study investigated options to manufacture stems utilizing methods that would replace crush form grinding while maintaining or improving quality at a comparative cost. Crush form grinding is a special process used at the Kansas City Plant to finish stem sections of reservoir products. However, crush form grinding is a complex process with many variables affecting the final product. This study identified two potential methods that can be applied to stems. Profile grinding was investigated in 2007. This project continued in 2008 proving that single point turning on a multi-turret is an option with additional benefits. It is an economical way to meet floor space limitations for our KCRIMS mission.
Date: September 25, 2008
Creator: Nguyen, Thuan
Object Type: Report
System: The UNT Digital Library
Simulations of The Dalles Dam Proposed Full Length Spillwall (open access)

Simulations of The Dalles Dam Proposed Full Length Spillwall

This report presents results of a computational fluid dynamics (CFD) modeling study to evaluatethe impacts of a full-length spillwall at The Dalles Dam. The full-length spillwall is being designed and evaluated as a structural means to improve tailrace egress and thus survival of juvenile fish passing through the spillway. During the course of this study, a full-length spillwall at Bays 6/7 and 8/9 were considered. The U.S. Army Corps of Engineers (USACE) has proposed extending the spillwall constructed in the stilling basin between spillway Bays 6 and 7 about 590 ft farther downstream. It is believed that the extension of the spillwall will improve egress conditions for downstream juvenile salmonids by moving them more rapidly into the thalweg of the river hence reducing their exposure to predators. A numerical model was created, validated, and applied the The Dalles Dam tailrace. The models were designed to assess impacts to flow, tailrace egress, navigation, and adult salmon passage of a proposed spill wall extension. The more extensive model validation undertaken in this study greatly improved our confidence in the numerical model to represent the flow conditions in The Dalles tailrace. This study used these validated CFD models to simulate the potential impacts …
Date: February 25, 2008
Creator: Rakowski, Cynthia L.; Perkins, William A.; Richmond, Marshall C. & Serkowski, John A.
Object Type: Report
System: The UNT Digital Library
Bechtel Jacobs Company LLC Sampling and Analysis Plan for the Water Resources Restoration Program for Fiscal Year 2009, Oak Ridge Reservation, Oak Ridge, Tennessee (open access)

Bechtel Jacobs Company LLC Sampling and Analysis Plan for the Water Resources Restoration Program for Fiscal Year 2009, Oak Ridge Reservation, Oak Ridge, Tennessee

The Oak Ridge Reservation (ORR) Water Resources Restoration Program (WRRP) was established by the U. S. Department of Energy (DOE) in 1996 to implement a consistent approach to long-term environmental monitoring across the ORR. The WRRP has four principal objectives: (1) to provide the data and technical analysis necessary to assess the performance of completed Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) actions on the ORR; (2) to perform monitoring to establish a baseline against which the performance of future actions will be gauged and to support watershed management decisions; (3) to perform interim-status and post-closure permit monitoring and reporting to comply with Resource Conservation and Recovery Act of 1976 (RCRA) requirements; and (4) to support ongoing waste management activities associated with WRRP activities. Water quality projects were established for each of the major facilities on the ORR: East Tennessee Technology Park (ETTP); Oak Ridge National Laboratory (ORNL), including Bethel Valley and Melton Valley; and the Y-12 National Security Complex (Y-12 Complex or Y-12), including Bear Creek Valley (BCV), Upper East Fork Poplar Creek (UEFPC), and Chestnut Ridge. Off-site (i.e., located beyond the ORR boundary) sampling requirements are also managed as part of the Y-12 Water Quality …
Date: September 25, 2008
Creator: R.H., Ketelle
Object Type: Report
System: The UNT Digital Library
Jack Rabbit Pretest 2021E PT3 Photonic Doppler Velocimetry Data Volume 3 Section 1 (open access)

Jack Rabbit Pretest 2021E PT3 Photonic Doppler Velocimetry Data Volume 3 Section 1

The Jack Rabbit Pretest (PT) 2021E PT3 was fired on March 12, 2008 at the Contained Firing Facility, Site 300, Lawrence Livermore National Laboratory. This experiment is part of an effort to determine the properties of LX-17 in a regime where corner-turning behavior and dead-zone formation are not well understood. Photonic Doppler Velocimetry (PDV) measured diagnostic plate velocities confirming the presence of a persistent LX-17 dead-zone formation and the resultant impulse gradient applied under the diagnostic plate. The Jack Rabbit Pretest 2021E PT3, 120 millimeter diameter experiment returned data on all eight PDV probes. The probes measured on the central axis and at 10, 20, 25, 30, 35, 40, 50 millimeters from the central axis. The experiment was shot at an ambient room temperature of 65 degrees Fahrenheit. The earliest PDV signal extinction was 41.7 microseconds at 30 millimeters. The latest PDV signal extinction time was 65.0 microseconds at 10 millimeters. The measured velocity ranged from meters per second to thousands of meters per second. First detonation wave induced jump-off was measured at 40 millimeters at 10.9 microseconds. The PDV data provided an unambiguous indication of dead-zone formation and an impulse gradient applied to the diagnostic plate. The central axis …
Date: June 25, 2008
Creator: Hart, M. M.; Strand, O. T.; Bosson, S. T.; Bonner, R. A. & Hester, D. M.
Object Type: Report
System: The UNT Digital Library
Sunyaev-Zel'Dovich effect observations of the bullet cluster (1E 0657-56) with APEX-SZ (open access)

Sunyaev-Zel'Dovich effect observations of the bullet cluster (1E 0657-56) with APEX-SZ

We present observations of the Sunyaev-Zel'dovich effect (SZE) in the Bullet cluster (1E 0657-56) using the APEX-SZ instrument at 150 GHz with a resolution of 1'. The main results are maps of the SZE in this massive, merging galaxy cluster. The cluster is detected with 23 sigma significance within the central 1' radius of the source position. The SZE map has a broadly similar morphology to that in existing X-ray maps of this system, and we find no evidence for significant contamination of the SZE emission by radio or IR sources. In order to make simple quantitative comparisons with cluster gas models derived from X-ray observations, we fit our data to an isothermal elliptical beta model, despite the inadequacy of such a model for this complex merging system. With an X-ray derived prior on the power-law index, beta = 1.04+0.16-0.10, we find a core radius rc = 142" +- 18", an axial ratio of 0.889 +- 0.072, and a central temperature decrement of -771 +- 71 muKCMB, including a +-5.5percent flux calibration uncertainty. Combining the APEX-SZ map with a map of projected electron surface density from Chandra X-ray observations, we determine the mass-weighted temperature of the cluster gas to be …
Date: July 25, 2008
Creator: Halverson, N. W.; Lanting, T.; Ade, P. A. R.; Basu, K.; Bender, A. N.; Benson, B. A. et al.
Object Type: Article
System: The UNT Digital Library
Fall Chinook Salmon Spawning Ground Surveys in the Snake River Basin Upriver of Lower Granite Dam, 2007 Annual Report. (open access)

Fall Chinook Salmon Spawning Ground Surveys in the Snake River Basin Upriver of Lower Granite Dam, 2007 Annual Report.

Redd counts are routinely used to document the spawning distribution of fall Chinook salmon (Oncorhynchus tshawytscha) in the Snake River basin upriver of Lower Granite Dam. The first reported redd counts were from aerial searches conducted intermittently between 1959 and 1978 (Irving and Bjornn 1981, Witty 1988; Groves and Chandler 1996)(Appendix 1). In 1986, the Washington Department of Fish and Wildlife began an annual monitoring program that, in addition to the Snake River, included aerial searches of the Grande Ronde River the first year (Seidel and Bugert 1987), and the Imnaha River in subsequent years (Seidel et al. 1988; Bugert et al. 1989-1991; Mendel et al. 1992). The U. S. Fish and Wildlife Service and Idaho Power Company began contributing to this effort in 1991 by increasing the number of aerial searches conducted each year and adding underwater searches in areas of the Snake River that were too deep to be searched from the air (Connor et al. 1993; Garcia et al. 1994a, 1994b, 1996-2007; Groves 1993; Groves and Chandler 1996). The Nez Perce Tribe added aerial searches in the Clearwater River basin beginning in 1988 (Arnsberg et. al 1992), and the Salmon River beginning in 1992. Currently searches are …
Date: November 25, 2008
Creator: Garcia, A.P.; Bradbury, S.; Arnsberg, B.D. & Groves, P.A.
Object Type: Report
System: The UNT Digital Library
Space charge effect in isochronous rings (open access)

Space charge effect in isochronous rings

Cyclotrons, rings for precise nuclear mass spectrometry, and some light sources with extremely short bunches are operated or planned to be operated in the isochronous or almost isochronous regime. Also, many hadron synchrotrons run in the isochronous regime for a short period of time during transition crossing. The longitudinal motion is frozen in the isochronous regime that leads to accumulation of the integral of the longitudinal space charge force. In low-gamma hadron machines, this can cause a fast growth of the beam energy spread even at modest beam intensities. Additionally, the transverse component of the space charge effectively modifies the dispersion function and the slip factor shifting the isochronous (transition) point. In this paper, we discuss space charge effects in the isochronous regime and present experimental results obtained in the Small Isochronous Ring, developed at Michigan State University specifically for studies of space charge in the isochronous regime.
Date: August 25, 2008
Creator: Pozdeyev, E.; Rodriguez, J. A.; Marti, F. & York, R.
Object Type: Article
System: The UNT Digital Library
The eukaryotic translation elongation factor eEF1A2 induces neoplastic properties and mediates tumorigenic effects of ZNF217 in precursor cells of human ovarian carcinomas (open access)

The eukaryotic translation elongation factor eEF1A2 induces neoplastic properties and mediates tumorigenic effects of ZNF217 in precursor cells of human ovarian carcinomas

Ovarian epithelial carcinomas (OEC) frequently exhibit amplifications at the 20q13 locus which is the site of several oncogenes, including the eukaryotic elongation factor EEF1A2 and the transcription factor ZNF217. We reported previously that overexpressed ZNF217 induces neoplastic characteristics in precursor cells of OEC. Unexpectedly, ZNF217, which is a transcriptional repressor, enhanced expression of eEF1A2. In this study, array comparative genomic hybridization, single nucleotide polymorphism and Affymetrix analysis of ZNF217-overexpressing cell lines confirmed consistently increased expression of eEF1A2 but not of other oncogenes, and revealed early changes in EEF1A2 gene copy numbers and increased expression at crisis during immortalization. We defined the influence of eEF1A2 overexpression on immortalized ovarian surface epithelial cells, and investigated interrelationships between effects of ZNF217 and eEF1A2 on cellular phenotypes. Lentivirally induced eEF1A2 overexpression caused delayed crisis, apoptosis resistance and increases in serum-independence, saturation densities, and anchorage independence. siRNA to eEF1A2 reversed apoptosis resistance and reduced anchorage independence in eEF1A2-overexpressing lines. Remarkably, siRNA to eEF1A2 was equally efficient in inhibiting both anchorage independence and resistance to apoptosis conferred by ZNF217 overexpression. Our data define neoplastic properties that are caused by eEF1A2 in nontumorigenic ovarian cancer precursor cells, and suggest that eEF1A2 plays a role in mediating ZNF217-induced …
Date: April 25, 2008
Creator: Sun, Yu; Wong, Nicholas; Guan, Yinghui; Salamanca, Clara M.; Cheng, Jung Chien; Lee, Jonathan M. et al.
Object Type: Article
System: The UNT Digital Library
Uranium Metal Reaction Behavior in Water, Sludge, and Grout Matrices (open access)

Uranium Metal Reaction Behavior in Water, Sludge, and Grout Matrices

This report summarizes information and data on the reaction behavior of uranium metal in water, in water-saturated simulated and genuine K Basin sludge, and in grout matrices. This information and data are used to establish the technical basis for metallic uranium reaction behavior for the K Basin Sludge Treatment Project (STP). The specific objective of this report is to consolidate the various sources of information into a concise document to serve as a high-level reference and road map for customers, regulators, and interested parties outside the STP (e.g., external reviewers, other DOE sites) to clearly understand the current basis for the corrosion of uranium metal in water, sludge, and grout.
Date: September 25, 2008
Creator: Delegard, Calvin H. & Schmidt, Andrew J.
Object Type: Report
System: The UNT Digital Library
Fish Passage Center 2007 Annual Report. (open access)

Fish Passage Center 2007 Annual Report.

The January-July runoff volume above the Dalles Dam in 2007 was 89% of the average runoff volume for the 1971-2000 historical record. The April-July runoff volume at Lower Granite Dam was 68% of the 1971-2000 historical record. Over the 79 year historical record from 1929 through 2007, the 2007 January-July runoff volume at the Dalles was the 50th lowest year out of the 79th year record. The January through July runoff volume at Lower Granite was the 65th lowest runoff year out of 79 on record. This year can be characterized by steadily decreasing snowpack which was below average in the Columbia Basin by the end of April. The combination of runoff volume, decreasing snowpack and reservoir operations resulted in spring migration flows at McNary Dam averaging 239 Kcfs, slightly above the Biological Opinion flow objective of 237 Kcfs. However the spring period migration flows in the Snake River averaged 61 Kcfs at Lower Granite Dam, substantially below the Biological Opinion flow objective of 85 Kcfs. Summer migration period Biological Opinion flow objectives averaged 163 Kcfs at McNary Dam, substantially below the summer flow objective of 200 Kcfs. Summer migration period flows in the Snake River at Lower Granite Dam …
Date: November 25, 2008
Creator: DeHart, Michele
Object Type: Report
System: The UNT Digital Library
Quantum Operation Time Reversal (open access)

Quantum Operation Time Reversal

The dynamics of an open quantum system can be described by a quantum operation: A linear, complete positive map of operators. Here, I exhibit a compact expression for the time reversal of a quantum operation, which is closely analogous to the time reversal of a classical Markov transition matrix. Since open quantum dynamics are stochastic, and not, in general, deterministic, the time reversal is not, in general, an inversion of the dynamics. Rather, the system relaxes toward equilibrium in both the forward and reverse time directions. The probability of a quantum trajectory and the conjugate, time reversed trajectory are related by the heat exchanged with the environment.
Date: March 25, 2008
Creator: Crooks, Gavin E.
Object Type: Article
System: The UNT Digital Library
Heterogeneous seepage at the Nopal I natural analogue site, Chihuahua, Mexico (open access)

Heterogeneous seepage at the Nopal I natural analogue site, Chihuahua, Mexico

An integrated field, laboratory, and modeling study of the Pena Blanca (Chihuahua, Mexico) natural analogue site is being conducted to evaluate processes that control the mobilization and transport of radionuclides from a uranium ore deposit. One component of this study is an evaluation of the potential for radionuclide transport through the unsaturated zone (UZ) via a seepage study in an adit at the Nopal I uranium mine, excavated 10 m below a mined level surface. Seasonal rainfall on the exposed level surface infiltrates into the fractured rhyolitic ash-flow tuff and seeps into the adit. An instrumented seepage collection system and local automated weather station permit direct correlation between local precipitation events and seepage within the Nopal I +00 adit. Monitoring of seepage within the adit between April 2005 and December 2006 indicates that seepage is highly heterogeneous with respect to time, location, and quantity. Within the back adit area, a few zones where large volumes of water have been collected are linked to fast flow path fractures (0-4 h transit times) presumably associated with focused flow. In most locations, however, there is a 1-6 month time lag between major precipitation events and seepage within the adit, with longer residence times …
Date: October 25, 2008
Creator: Dobson, Patrick F.; Cook, Paul J.; Ghezzehei, Teamrat A.; Rodriguez, J. Alfredo; Villalba, Lourdes & de la Garza, Rodrigo
Object Type: Article
System: The UNT Digital Library
From Antenna to Assay: Lessons Learned in Lanthanide Luminescence (open access)

From Antenna to Assay: Lessons Learned in Lanthanide Luminescence

Ligand-sensitized luminescent lanthanide(III) complexes are of considerable current interest due to their unique photophysical properties (micro- to millisecond lifetimes, characteristic and narrow emission bands, and large Stokes shifts), which make them well suited to serve as labels in fluorescence-based bioassays. The long-lived Ln(III) emission can be temporally resolved from scattered light and background fluorescence, resulting in vastly enhanced measurement sensitivity. One of the challenges in this field is the design of sensitizing ligands that provide highly emissive Ln(III) complexes that also possess sufficient stability and aqueous solubility required for practical applications. In this account we give an overview of some of the general properties of the trivalent lanthanides and follow with a summary of advances made in our laboratory in the development of highly luminescent Tb(III) and Eu(III) complexes for applications in biotechnology. A focus of our research has been the optimization of these compounds as potential commercial agents for use in Homogeneous Time Resolved Fluorescence (HTRF) technology, the requirements and current use of which will be briefly discussed. Our approach involves developing high-stability octadentate Tb(III) and Eu(III) complexes that rely on all-oxygen donor atoms as well as using multi-chromophore chelates to increase molar absorptivity compared to earlier examples that …
Date: September 25, 2008
Creator: Moore, Evan; Samuel, Amanda & Raymond, Kenneth
Object Type: Article
System: The UNT Digital Library
ERHIC Conceptual Design (open access)

ERHIC Conceptual Design

The conceptual design of the high luminosity electron-ion collider, eRHIC, is presented. The goal of eRHIC is to provide collisions of electrons (and possibly positrons) with ions and protons at the center-of-mass energy range from 25 to 140 GeV, and with luminosities exceeding 10{sup 33} cm{sup -2} s{sup -1}. A considerable part of the physics program is based on polarized electrons, protons and He3 ions with high degree of polarization. In eRHIC electron beam will be accelerated in an energy recovery linac. Major R&D items for eRHIC include the development of a high intensity polarized electron source, studies of various aspects of energy recovery technology for high power beams and the development of compact magnets for recirculating passes. In eRHIC scheme the beam-beam interaction has several specific features, which have to be thoroughly studied. In order to maximize the collider luminosity, several upgrades of the existing RHIC accelerator are required. Those upgrades may include the increase of intensity as well as transverse and longitudinal cooling of ion and proton beams.
Date: August 25, 2008
Creator: Ptitsyn, V.; Beebe-Wang, J.; Ben-Zvi, Ilan; Fedotov, A.; Fischer, W.; Hao, Y. et al.
Object Type: Article
System: The UNT Digital Library
Jack Rabbit Pretest 2021E PT4 Photonic Doppler Velocimetry Data Volume 4 Section 1 (open access)

Jack Rabbit Pretest 2021E PT4 Photonic Doppler Velocimetry Data Volume 4 Section 1

The Jack Rabbit Pretest (PT) 2021E PT4 was fired on March 19, 2008 at the Contained Firing Facility, Site 300, Lawrence Livermore National Laboratory. This experiment is part of an effort to determine the properties of LX-17 in a regime where corner-turning behavior and dead-zone formation are not well understood. Photonic Doppler Velocimetry (PDV) measured diagnostic plate velocities confirming the presence of a persistent LX-17 dead-zone formation and the resultant impulse gradient applied under the diagnostic plate. The Jack Rabbit Pretest 2021E PT4, 120 millimeter diameter experiment returned data on all eight PDV probes. The probes measured on the central axis and at 10, 20, 25, 30, 35, 40, 50 millimeters from the central axis. The experiment was shot at an ambient room temperature of 64 degrees Fahrenheit. The earliest PDV signal extinction was 44.9 microseconds at 30 millimeters. The latest PDV signal extinction time was 69.5 microseconds at 10 millimeters. The measured velocity ranged from meters per second to thousands of meters per second. First detonation wave induced jump-off was measured at 50 millimeters at 13.3 microseconds. The PDV data provided an unambiguous indication of dead-zone formation and an impulse gradient applied to the diagnostic plate. The central axis …
Date: June 25, 2008
Creator: Hart, M. M.; Strand, O. T.; Bosson, S. T.; Bonner, R. A. & Hester, D. M.
Object Type: Report
System: The UNT Digital Library
Jack Rabbit Pretest 2021E PT6 Photonic Doppler Velocimetry Data Volume 6 Section 1 (open access)

Jack Rabbit Pretest 2021E PT6 Photonic Doppler Velocimetry Data Volume 6 Section 1

The Jack Rabbit Pretest (PT) 2021E PT6 experiment was fired on April 1, 2008 at the Contained Firing Facility, Site 300, Lawrence Livermore National Laboratory. This experiment is part of an effort to determine the properties of LX-17 in a regime where corner-turning behavior and dead-zone formation are not well understood. Photonic Doppler Velocimetry (PDV) measured diagnostic plate velocities confirming the presence of a persistent LX-17 dead-zone formation and the resultant impulse gradient applied under the diagnostic plate. The Jack Rabbit Pretest 2021E PT6, 160 millimeter diameter experiment returned data on all eight PDV probes. The probes measured on the central axis and at 20, 30, 35, 45, 55, 65, 75 millimeters from the central axis. The experiment was shot at an ambient room temperature of 65 degrees Fahrenheit. The earliest PDV signal extinction was 54.2 microseconds at 30 millimeters. The latest PDV signal extinction time was 64.5 microseconds at the central axis. The measured velocity ranged from meters per second to thousands of meters per second. First detonation wave induced jump-off was measured at 55 millimeters at 14.1 microseconds. The PDV data provided an unambiguous indication of dead-zone formation and an impulse gradient applied to the diagnostic plate. The …
Date: June 25, 2008
Creator: Hart, M. M.; Strand, O. T.; Bosson, S. T.; Bonner, R. A. & Hester, D. M.
Object Type: Report
System: The UNT Digital Library
Monodromy in the CMB: Gravity Waves and String Inflation (open access)

Monodromy in the CMB: Gravity Waves and String Inflation

None
Date: March 25, 2008
Creator: Silverstein, Eva & Westphal, Alexander
Object Type: Report
System: The UNT Digital Library
Advanced Techniques for Power System Identification from Measured Data (open access)

Advanced Techniques for Power System Identification from Measured Data

Time-synchronized measurements provide rich information for estimating a power-system's electromechanical modal properties via advanced signal processing. This information is becoming critical for the improved operational reliability of interconnected grids. A given mode's properties are described by its frequency, damping, and shape. Modal frequencies and damping are useful indicators of power-system stress, usually declining with increased load or reduced grid capacity. Mode shape provides critical information for operational control actions. This project investigated many advanced techniques for power system identification from measured data focusing on mode frequency and damping ratio estimation. Investigators from the three universities coordinated their effort with Pacific Northwest National Laboratory (PNNL). Significant progress was made on developing appropriate techniques for system identification with confidence intervals and testing those techniques on field measured data and through simulation. Experimental data from the western area power system was provided by PNNL and Bonneville Power Administration (BPA) for both ambient conditions and for signal injection tests. Three large-scale tests were conducted for the western area in 2005 and 2006. Measured field PMU (Phasor Measurement Unit) data was provided to the three universities. A 19-machine simulation model was enhanced for testing the system identification algorithms. Extensive simulations were run with this model …
Date: November 25, 2008
Creator: Pierre, John W.; Wies, Richard & Trudnowski, Daniel
Object Type: Report
System: The UNT Digital Library
Light-Front Holography and Hadronization at the Amplitude Level (open access)

Light-Front Holography and Hadronization at the Amplitude Level

The correspondence between theories in anti-de Sitter space and conformal field theories in physical space-time leads to an analytic, semiclassical model for strongly-coupled QCD which has scale invariance at short distances and color confinement at large distances. Light-front holography is a remarkable feature of AdS/CFT: it allows hadronic amplitudes in the AdS fifth dimension to be mapped to frame-independent light-front wavefunctions of hadrons in physical space-time, thus providing a relativistic description of hadrons at the amplitude level. Some novel features of QCD are discussed, including the consequences of confinement for quark and gluon condensates and the behavior of the QCD coupling in the infrared. We suggest that the spatial support of QCD condensates is restricted to the interior of hadrons, since they arise due to the interactions of confined quarks and gluons. Chiral symmetry is thus broken in a limited domain of size 1=m{sub {pi}} in analogy to the limited physical extent of superconductor phases. A new method for computing the hadronization of quark and gluon jets at the amplitude level, an event amplitude generator, is outlined.
Date: July 25, 2008
Creator: Brodsky, Stanley J.; de Teramond, Guy & Shrock, Robert
Object Type: Article
System: The UNT Digital Library
Metabolic engineering of Saccharomyces cerevisiae for the production of n-butanol (open access)

Metabolic engineering of Saccharomyces cerevisiae for the production of n-butanol

BackgroundIncreasing energy costs and environmental concerns have motivated engineering microbes for the production of ?second generation? biofuels that have better properties than ethanol.Results& ConclusionsSaccharomyces cerevisiae was engineered with an n-butanol biosynthetic pathway, in which isozymes from a number of different organisms (S. cerevisiae, Escherichia coli, Clostridium beijerinckii, and Ralstonia eutropha) were substituted for the Clostridial enzymes and their effect on n-butanol production was compared. By choosing the appropriate isozymes, we were able to improve production of n-butanol ten-fold to 2.5 mg/L. The most productive strains harbored the C. beijerinckii 3-hydroxybutyryl-CoA dehydrogenase, which uses NADH as a co-factor, rather than the R. eutropha isozyme, which uses NADPH, and the acetoacetyl-CoA transferase from S. cerevisiae or E. coli rather than that from R. eutropha. Surprisingly, expression of the genes encoding the butyryl-CoA dehydrogenase from C. beijerinckii (bcd and etfAB) did not improve butanol production significantly as previously reported in E. coli. Using metabolite analysis, we were able to determine which steps in the n-butanol biosynthetic pathway were the most problematic and ripe for future improvement.
Date: November 25, 2008
Creator: Steen, EricJ.; Chan, Rossana; Prasad, Nilu; Myers, Samuel; Petzold, Christopher; Redding, Alyssa et al.
Object Type: Article
System: The UNT Digital Library
DEFENSE WASTE PROCESSING FACILITY ANALYTICAL METHOD VERIFICATION FOR THE SLUDGE BATCH 5 QUALIFICATION SAMPLE (open access)

DEFENSE WASTE PROCESSING FACILITY ANALYTICAL METHOD VERIFICATION FOR THE SLUDGE BATCH 5 QUALIFICATION SAMPLE

For each sludge batch that is processed in the Defense Waste Processing Facility (DWPF), the Savannah River National Laboratory (SRNL) performs confirmation of the applicability of the digestion method to be used by the DWPF lab for elemental analysis of Sludge Receipt and Adjustment Tank (SRAT) receipt samples and SRAT product process control samples. DWPF SRAT samples are typically dissolved using a room temperature HF-HNO3 acid dissolution (i.e., DWPF Cold Chem Method, see Procedure SW4-15.201) and then analyzed by inductively coupled plasma - atomic emission spectroscopy (ICP-AES). This report contains the results and comparison of data generated from performing the Aqua Regia (AR), Sodium Peroxide/Hydroxide Fusion (PF) and DWPF Cold Chem (CC) method digestion of Sludge Batch 5 (SB5) SRAT Receipt and SB5 SRAT Product samples. The SB5 SRAT Receipt and SB5 SRAT Product samples were prepared in the SRNL Shielded Cells, and the SRAT Receipt material is representative of the sludge that constitutes the SB5 Batch composition. This is the sludge in Tank 51 that is to be transferred into Tank 40, which will contain the heel of Sludge Batch 4 (SB4), to form the SB5 Blend composition. The results for any one particular element should not be used …
Date: July 25, 2008
Creator: Click, D; Tommy Edwards, T & Henry Ajo, H
Object Type: Report
System: The UNT Digital Library