Final Technical Report (open access)

Final Technical Report

During the 1-year duration of this project a new Shortwave Spectrometer (SWS) was designed and developed for deployment at the Southern Great Plains Central Facility to measure zenith solar spectral radiance. The SWS is comprised of two Zeiss miniature monolithic spectrometers (MMS-1 and MMS-NIR) for visible and near-infrared detection in the wavelength range between 350 and 2250 nm. Spectral resolution is 8 nm for the MMS-1 and 12 nm for the MMS-NIR. The light collector is a narrow field of view (±1.5 º) collimator at the front end of a high-grade custom-made fiber optic bundle. The data acquisition and control system is a 933 MHz Pentium based PC in a PC104 format with a USB interface between the computer and the spectrometers. Spectral sampling rate is approximately 1 Hz. A prototype SWS was deployed at SGP in November and December 2004 and it collected zenith-sky solar spectra at 1 Hz continuously over a 29 day period. Prior to deployment it was calibrated and characterized at the NASA Ames Airborne Sensor Facility (ASF) using a 30 inch Integrating Sphere. The SWS was also calibrated using a portable 12 inch integrating sphere at the Central Facility. The testing and calibration procedures were …
Date: May 27, 2009
Creator: Pilewskie, Peter
Object Type: Report
System: The UNT Digital Library
Measurements of CKM angles beta/phi_1 and alpha/phi_2 at the Babar and Belle experiments. (open access)

Measurements of CKM angles beta/phi_1 and alpha/phi_2 at the Babar and Belle experiments.

We report measurements of the CKM angles {beta}/{phi}{sub 1} and {alpha}/{phi}{sub 2} done by the BABAR and Belle experiments. Both experiments have collected large data samples, corresponding to a total of more than 1 billion of B{bar B} pairs, at the e{sup +}e{sup -} asymmetric-energy colliders PEP-II (SLAC) and KEK-B (KEK), respectively.
Date: May 7, 2009
Creator: Lazzaro, A.
Object Type: Article
System: The UNT Digital Library
Performance Evaluation for Modular, Scalable Cooling Systems with Hot Aisle Containment in Data Centers (open access)

Performance Evaluation for Modular, Scalable Cooling Systems with Hot Aisle Containment in Data Centers

Scientific and enterprise data centers, IT equipment product development, and research data center laboratories typically require continuous cooling to control inlet air temperatures within recommended operating levels for the IT equipment. The consolidation and higher density aggregation of slim computing, storage and networking hardware has resulted in higher power density than what the raised-floor system design, coupled with commonly used computer rack air conditioning (CRAC) units, was originally conceived to handle. Many existing data centers and newly constructed data centers adopt CRAC units, which inherently handle heat transfer within data centers via air as the heat transfer media. This results in energy performance of the ventilation and cooling systems being less than optimal. Understanding the current trends toward higher power density in IT computing, more and more IT equipment manufacturers are designing their equipment to operate in 'conventional' data center environments, while considering provisions of alternative cooling solutions to either their equipment or supplemental cooling in rack or row systems. Naturally, the trend toward higher power density resulting from current and future generations of servers has, in the meanwhile, created significant opportunities for precision cooling suppliers to engineer and manufacture packaged modular and scalable systems. The modular and scalable cooling …
Date: May 1, 2009
Creator: Adams, Barbara J
Object Type: Report
System: The UNT Digital Library
Wind Shear and Turbulence Profiles at Elevated Heights: Great Lakes and Midwest Sites (Poster) (open access)

Wind Shear and Turbulence Profiles at Elevated Heights: Great Lakes and Midwest Sites (Poster)

Analyzed wind resource characteristics at elevated heights (50 m-200+m) incuding shear and turbulence profiles for some areas of the Great Lakes and M idwest sites.
Date: May 1, 2009
Creator: Elliott, D.; Schwartz, M. & Scott, G.
Object Type: Article
System: The UNT Digital Library
Fermilab Main Injector Collimation Systems: Design, Commissioning and Operation (open access)

Fermilab Main Injector Collimation Systems: Design, Commissioning and Operation

The Fermilab Main Injector is moving toward providing 400 kW of 120 GeV proton beams using slip stacking injection of eleven Booster batches. Loss of 5% of the beam at or near injection energy results in 1.5 kW of beam loss. A collimation system has been implemented to localize this loss with the design emphasis on beam not captured in the accelerating RF buckets. More than 95% of these losses are captured in the collimation region. We will report on the construction, commissioning and operation of this collimation system. Commissioning studies and loss measurement tools will be discussed. Residual radiation monitoring of the Main Injector machine components will be used to demonstrate the effectiveness of these efforts.
Date: May 1, 2009
Creator: Brown, Bruce; Adamson, Philip; Capista, David; Drozhdin, A.I.; Johnson, David E.; Kourbanis, Ioanis et al.
Object Type: Article
System: The UNT Digital Library
Top quark pair production cross section at Tevatron (open access)

Top quark pair production cross section at Tevatron

An overview of the recent measurements of the top antitop quark pair production cross section in proton antiproton collisions at {radical}s = 1.96 TeV in lepton + jets and dilepton final states is presented. These measurements are based on 1-2.8 fb{sup -1} of data collected with the D0 and CDF experiments at the Fermilab Tevatron collider. The cross section is measured with a precision close to 8 % and found to be compatible with the standard model prediction. Interpretations of the cross-section measurements for charge higgs search and for top quark mass measurement are also discussed.
Date: May 1, 2009
Creator: Shary, V. & /DAPNIA, Saclay
Object Type: Article
System: The UNT Digital Library
3D Simulations of Secondary Electron Generation and Transport in a Diamond Electron Beam Amplifier (open access)

3D Simulations of Secondary Electron Generation and Transport in a Diamond Electron Beam Amplifier

The Relativistic Heavy Ion Collider (RHIC) contributes fundamental advances to nuclear physics by colliding a wide range of ions. A novel electron cooling section, which is a key component of the proposed luminosity upgrade for RHIC, requires the acceleration of high-charge electron bunches with low emittance and energy spread. A promising candidate for the electron source is the recently developed concept of a high quantum efficiency photoinjector with a diamond amplifier. To assist in the development of such an electron source, we have implemented algorithms within the VORPAL particle-in-cell framework for modeling secondary electron and hole generation, and for charge transport in diamond. The algorithms include elastic, phonon, and impurity scattering processes over a wide range of charge carrier energies. Results from simulations using the implemented capabilities will be presented and discussed.
Date: May 4, 2009
Creator: Busby, R.; Rao, T.; Dimitrov, D. A.; Cary, J. R.; Ben-Zvi, Ilan; Chang, X. et al.
Object Type: Article
System: The UNT Digital Library
Alternative Financing for Energy Efficiency and Renewable Energy: Quick Guide (open access)

Alternative Financing for Energy Efficiency and Renewable Energy: Quick Guide

Overview of alternative financing mechanisms avaiable to Federal agencies to fund renewable energy and energy efficiency projects.
Date: May 1, 2009
Creator: United States. Department of Energy.
Object Type: Report
System: The UNT Digital Library
Distinct kinetics of human DNA ligases I, IIIalpha, IIIbeta, and IV reveal direct DNA sensing ability and differential physiological functions in DNA repair (open access)

Distinct kinetics of human DNA ligases I, IIIalpha, IIIbeta, and IV reveal direct DNA sensing ability and differential physiological functions in DNA repair

The three human LIG genes encode polypeptides that catalyze phosphodiester bond formation during DNA replication, recombination and repair. While numerous studies have identified protein partners of the human DNA ligases (hLigs), there has been little characterization of the catalytic properties of these enzymes. In this study, we developed and optimized a fluorescence-based DNA ligation assay to characterize the activities of purified hLigs. Although hLigI joins DNA nicks, it has no detectable activity on linear duplex DNA substrates with short, cohesive single-strand ends. By contrast, hLigIII{beta} and the hLigIII{alpha}/XRCC1 and hLigIV/XRCC4 complexes are active on both nicked and linear duplex DNA substrates. Surprisingly, hLigIV/XRCC4, which is a key component of the major non-homologous end joining (NHEJ) pathway, is significantly less active than hLigIII on a linear duplex DNA substrate. Notably, hLigIV/XRCC4 molecules only catalyze a single ligation event in the absence or presence of ATP. The failure to catalyze subsequent ligation events reflects a defect in the enzyme-adenylation step of the next ligation reaction and suggests that, unless there is an in vivo mechanism to reactivate DNA ligase IV/XRCC4 following phosphodiester bond formation, the cellular NHEJ capacity will be determined by the number of adenylated DNA ligaseIV/XRCC4 molecules.
Date: May 11, 2009
Creator: Chen, Xi; Ballin, Jeff D.; Della-Maria, Julie; Tsai, Miaw-Sheue; White, Elizabeth J.; Tomkinson, Alan E. et al.
Object Type: Article
System: The UNT Digital Library
Longitudinal space charge effects near transition (open access)

Longitudinal space charge effects near transition

Experimental and numerical studies of the longitudinal beam dynamics in the Small Isochronous Ring (SIR) at Michigan State University revealed a fast, space-charge driven instability that did not fit the model of the negative mass instability. This paper proposes a simple analytical model explaining these results. Also, the paper compares the model to result s of experimental and numerical studies of the longitudinal beam dynamics in SIR.
Date: May 4, 2009
Creator: Pozdeyev, E.; Rodriguez, J. A.; Marti, F. & York, R.C.
Object Type: Article
System: The UNT Digital Library
Correlation method for the measure of mask-induced line-edge roughness in extreme ultraviolet lithography (open access)

Correlation method for the measure of mask-induced line-edge roughness in extreme ultraviolet lithography

As critical dimensions for leading-edge semiconductor devices shrink, line-edge roughness (LER) requirements are pushing well into the single digit nanometer regime. At these scales many new sources of LER must be considered. In the case of extreme ultraviolet (EUV) lithography, modeling has shown the lithographic mask to be a source of significant concern. Here we present a correlation-based methodology for experimentally measuring the magnitude of mask contributors to printed LER. The method is applied to recent printing results from a 0.3 numerical aperture EUV microfield exposure tool. The measurements demonstrate that such effects are indeed present and of significant magnitude. The method is also used to explore the effects of illumination coherence and defocus and has been used to verify model-based predictions of mask-induced LER.
Date: May 25, 2009
Creator: Naulleau, Patrick
Object Type: Article
System: The UNT Digital Library
Integrating the MANX 6-D Muon Cooling Experiment with the MICE Spectrometers (open access)

Integrating the MANX 6-D Muon Cooling Experiment with the MICE Spectrometers

The MANX experiment is to demonstrate the reduction of 6D muon phase space emittance using a continuous liquid absorber to provide ionization cooling in a helical solenoid magnetic channel. The experiment involves the construction of a short two-period long helical cooling channel (HCC) to reduce the muon invariant emittance by a factor of two. The HCC would replace the current cooling section of the MICE experiment now being setup at the Rutherford Appleton Laboratory. The MANX experiment would use the existing MICE spectrometers and muon beam line. This paper shall consider the various approaches to integrate MANX into the RAL hall using the MICE spectrometers. This study shall discuss the matching schemes used to minimize losses and prevent emittance growth between the MICE spectrometers and the MANX HCC. Also the placement of additional detection planes in the matching region and the HCC to improve the resolution will be examined.
Date: May 1, 2009
Creator: Kahn, S. A.; Abrams, R. J.; Ankenbrandt, C.; Cummings, M. A. C.; Johnson, R. P.; Roberts, T. et al.
Object Type: Article
System: The UNT Digital Library
Performance Evaluation for Modular, Scalable Liquid-Rack Cooling Systems in Data Centers (open access)

Performance Evaluation for Modular, Scalable Liquid-Rack Cooling Systems in Data Centers

Scientific and enterprise data centers, IT equipment product development, and research data center laboratories typically require continuous cooling to control inlet air temperatures within recommended operating levels for the IT equipment. The consolidation and higher density aggregation of slim computing, storage and networking hardware has resulted in higher power density than what the raised-floor system design, coupled with commonly used computer rack air conditioning (CRAC) units, was originally conceived to handle. Many existing data centers and newly constructed data centers adopt CRAC units, which inherently handle heat transfer within data centers via air as the heat transfer media. This results in energy performance of the ventilation and cooling systems being less than optimal. Understanding the current trends toward higher power density in IT computing, more and more IT equipment manufacturers are designing their equipment to operate in 'conventional' data center environments, while considering provisions of alternative cooling solutions to either their equipment or supplemental cooling in rack or row systems. In the meanwhile, the trend toward higher power density resulting from current and future generations of servers has created significant opportunities for precision cooling suppliers to engineer and manufacture packaged modular and scalable systems. The modular and scalable cooling systems …
Date: May 1, 2009
Creator: Xu, TengFang
Object Type: Report
System: The UNT Digital Library
VALIDATION OF ANALYTICAL METHODS AND INSTRUMENTATION FOR BERYLLIUM MEASUREMENT: REVIEW AND SUMMARY OF AVAILABLE GUIDES, PROCEDURES, AND PROTOCOLS (open access)

VALIDATION OF ANALYTICAL METHODS AND INSTRUMENTATION FOR BERYLLIUM MEASUREMENT: REVIEW AND SUMMARY OF AVAILABLE GUIDES, PROCEDURES, AND PROTOCOLS

Method validation is the process of evaluating whether an analytical method is acceptable for its intended purpose. For pharmaceutical methods, guidelines from the United States Pharmacopeia (USP), International Conference on Harmonisation (ICH), and the United States Food and Drug Administration (USFDA) provide a framework for performing such valications. In general, methods for regulatory compliance must include studies on specificity, linearity, accuracy, precision, range, detection limit, quantitation limit, and robustness. Elements of these guidelines are readily adapted to the issue of validation for beryllium sampling and analysis. This document provides a listing of available sources which can be used to validate analytical methods and/or instrumentation for beryllium determination. A literature review was conducted of available standard methods and publications used for method validation and/or quality control. A comprehensive listing of the articles, papers and books reviewed is given in the Appendix. Available validation documents and guides are listed therein; each has a brief description of application and use. In the referenced sources, there are varying approches to validation and varying descriptions of the valication process at different stages in method development. This discussion focuses on valication and verification of fully developed methods and instrumentation that have been offered up for use …
Date: May 27, 2009
Creator: Ekechukwu, A
Object Type: Article
System: The UNT Digital Library
Social Acceptance of Wind Power in the United States: Evaluating Stakeholder Perspectives (Poster) (open access)

Social Acceptance of Wind Power in the United States: Evaluating Stakeholder Perspectives (Poster)

As the wind industry strives to achieve 20% wind energy by 2030, maintaining high levels of social acceptance for wind energy will become increasingly important. Wind Powering America is currently researching stakeholder perspectives in the U.S. market and reviewing findings from wind energy projects around the world to better understand social acceptance barriers. Results from European studies show that acceptance varies widely depending on local community values. A preliminary survey shows similar results in the United States. Further research will be conducted to refine our understanding of key social acceptance barriers and evaluate the best ways to mitigate negative perspectives on wind power.
Date: May 1, 2009
Creator: Tegen, S. & Lantz, E.
Object Type: Article
System: The UNT Digital Library
IMPACT OF TIME / TEMPERATURE CURING CONDITIONS AND ALUMINATE CONCENTRATIONS ON SALTSTONE PROPERTIES (open access)

IMPACT OF TIME / TEMPERATURE CURING CONDITIONS AND ALUMINATE CONCENTRATIONS ON SALTSTONE PROPERTIES

This report addresses the impact of (1) the time and temperature curing conditions (profile) and (2) the impact of higher aluminate concentrations in the decontaminated salt solution on Saltstone processing and performance properties. The results demonstrate that performance properties as well as some of the processing properties of Saltstone are highly sensitive to the conditions of time and temperature under which curing occurs. This sensitivity is in turn dependent on the concentration of aluminate in the salt feed solution. In general, the performance properties and indicators (Young's modulus, compressive strength and total porosity) are reduced when curing is initially carried out under high temperature. However, this reduction in performance properties is dependent on the sequence of temperatures (the time/temperature profile) experienced during the curing process. That is, samples that are subjected to a 1, 2, 3 or 4 day curing time at 60 C followed by final curing at 22 C lead to performance properties that are significantly different than the properties of grouts allowed to cure for 1, 2, 3 or 4 days at 22 C followed by a treatment at 60 C. The performance properties of Saltstone cured in the sequence of higher temperature first are generally less …
Date: May 5, 2009
Creator: Harbour, J.; Edwards, T. & Williams, V.
Object Type: Report
System: The UNT Digital Library
B Lifetimes and Mixing (open access)

B Lifetimes and Mixing

The Tevatron experiments, CDF and D0, have produced a wealth of new B-physics results since the start of Run II in 2001. We've observed new B-hadrons, seen new effects, and increased many-fold the precision with which we know the properties of b-quark systems. In these proceedings, we will discuss two of the most fruitful areas in the Tevatron B-physics program: lifetimes and mixing. We'll examine the experimental issues driving these analyses, present a summary of the latest results, and discuss prospects for the future.
Date: May 1, 2009
Creator: Evans, Harold G.
Object Type: Article
System: The UNT Digital Library
IMG ER: A System for Microbial Genome Annotation Expert Review and Curation (open access)

IMG ER: A System for Microbial Genome Annotation Expert Review and Curation

A rapidly increasing number of microbial genomes are sequenced by organizations worldwide and are eventually included into various public genome data resources. The quality of the annotations depends largely on the original dataset providers, with erroneous or incomplete annotations often carried over into the public resources and difficult to correct. We have developed an Expert Review (ER) version of the Integrated Microbial Genomes (IMG) system, with the goal of supporting systematic and efficient revision of microbial genome annotations. IMG ER provides tools for the review and curation of annotations of both new and publicly available microbial genomes within IMG's rich integrated genome framework. New genome datasets are included into IMG ER prior to their public release either with their native annotations or with annotations generated by IMG ER's annotation pipeline. IMG ER tools allow addressing annotation problems detected with IMG's comparative analysis tools, such as genes missed by gene prediction pipelines or genes without an associated function. Over the past year, IMG ER was used for improving the annotations of about 150 microbial genomes.
Date: May 25, 2009
Creator: Markowitz, Victor M.; Mavromatis, Konstantinos; Ivanova, Natalia N.; Chen, I-Min A.; Chu, Ken & Kyrpides, Nikos C.
Object Type: Report
System: The UNT Digital Library
Ion bombardment in RF photoguns (open access)

Ion bombardment in RF photoguns

A linac-ring eRHIC design requires a high-intensity CW source of polarized electrons. An SRF gun is viable option that can deliver the required beam. Numerical simulations presented elsewhere have shown that ion bombardment can occur in an RF gun, possibly limiting lifetime of a NEA GaAs cathode. In this paper, we analytically solve the equations of motion of ions in an RF gun using the ponderomotive potential of the Rf field. We apply the method to the BNL 1/2-cell SRF photogun and demonstrate that a significant portion of ions produced in the gun can reach the cathode if no special precautions are taken. Also, the paper discusses possible mitigation techniques that can reduce the rate of ion bombardment.
Date: May 4, 2009
Creator: Pozdeyev, E.; Kayran, D. & Litvinenko, V. N.
Object Type: Article
System: The UNT Digital Library
A Generalized Framework for Auto-tuning Stencil Computations (open access)

A Generalized Framework for Auto-tuning Stencil Computations

This work introduces a generalized framework for automatically tuning stencil computations to achieve superior performance on a broad range of multicore architectures. Stencil (nearest-neighbor) based kernels constitute the core of many important scientific applications involving block-structured grids. Auto-tuning systems search over optimization strategies to find the combination of tunable parameters that maximizes computational efficiency for a given algorithmic kernel. Although the auto-tuning strategy has been successfully applied to libraries, generalized stencil kernels are not amenable to packaging as libraries. Studied kernels in this work include both memory-bound kernels as well as a computation-bound bilateral filtering kernel. We introduce a generalized stencil auto-tuning framework that takes a straightforward Fortran expression of a stencil kernel and automatically generates tuned implementations of the kernel in C or Fortran to achieve performance portability across diverse computer architectures.
Date: May 1, 2009
Creator: Kamil, Shoaib; Chan, Cy; Williams, Samuel; Oliker, Leonid; Shalf, John; Howison, Mark et al.
Object Type: Article
System: The UNT Digital Library
Redesign of the H-Bridge Switch Plate of the SNS High Voltage Converter Modulator (open access)

Redesign of the H-Bridge Switch Plate of the SNS High Voltage Converter Modulator

The 1-MW High Voltage Converter Modulators [1] have operated in excess of 250,000 hours at the Spallation Neutron Source. Increased demands on the accelerator performance require increased modulator reliability. An effort is underway at SLAC National Accelerator Laboratory to redesign the modulator H-bridge switch plate with the goals of increasing reliability and performance [2]. The major difference between the SLAC design and the existing design is the use of press-pack IGBTs. Compared to other packaging options, these IGBTs have been shown to have increased performance in pulsed-power applications, have increased cooling capability, and do not fragment and disassemble during a fault event. An overview of the SLAC switch plate redesign is presented. Design steps including electrical modeling of the modulator and H-bridge, development of an integrated IGBT clamping mechanism, and fault tests are discussed. Experimental results will be presented comparing electrical performance of the SLAC switch plate to the existing switchplate under normal and fault conditions.
Date: May 7, 2009
Creator: Kemp, M. A.; Burkhart, C.; Nguyen, M. N. & Anderson, D. E.
Object Type: Article
System: The UNT Digital Library
Preventing Absenteeism and Promoting Resilience Among Health Care Workers In Biological Emergencies (open access)

Preventing Absenteeism and Promoting Resilience Among Health Care Workers In Biological Emergencies

The ability to ensure adequate numbers of medical staff represents a crucial part of the medical response to any disaster. However, healthcare worker absenteeism during disasters, especially in the event of an attack of biological terrorism or an epidemic such as pandemic influenza, is a serious concern. Though a significant rate of absenteeism is often included as a baseline assumption in emergency planning, published reports on strategies to minimize absenteeism are comparatively few. This report documents interviews with managers and emergency response planners at hospitals and public health agencies and reviews existing survey data on healthcare worker absenteeism and studies of disasters to glean lessons about the needs of healthcare workers during those disasters. Based on this research, expected rates of absenteeism and individual determinants of absenteeism are presented along with recommendations of steps that hospitals, emergency medical services departments, public health organizations, and government agencies can take to meet the needs of healthcare workers and minimize absenteeism during a biological event.
Date: May 8, 2009
Creator: Lesperance, Ann M. & Miller, James S.
Object Type: Report
System: The UNT Digital Library
RF Breakdown Studies Using a 1.3 GHZ Test Cell (open access)

RF Breakdown Studies Using a 1.3 GHZ Test Cell

Many present and future particle accelerators are limited by the maximum electric gradient and peak surface fields that can be realized in RF cavities. Despite considerable effort, a comprehensive theory of RF breakdown has not been achieved and mitigation techniques to improve practical maximum accelerating gradients have had only limited success. Recent studies have shown that high gradients can be achieved quickly in 805 MHz RF cavities pressurized with dense hydrogen gas without the need for long conditioning times, because the dense gas can dramatically reduce dark currents and multipacting. In this project we use this high pressure technique to suppress effects of residual vacuum and geometry found in evacuated cavities to isolate and study the role of the metallic surfaces in RF cavity breakdown as a function of magnetic field, frequency, and surface preparation. A 1.3-GHz RF test cell with replaceable electrodes (e.g. Mo, Cu, Be, W, and Nb) and pressure barrier capable of operating both at high pressure and in vacuum has been designed and built, and preliminary testing has been completed. A series of detailed experiments is planned at the Argonne Wakefield Accelerator. At the same time, computer simulations of the RF Breakdown process will be carried …
Date: May 1, 2009
Creator: Sah, R.; Johnson, R. P.; Neubauer, M.; Conde, M.; Gai, W.; Moretti, A. et al.
Object Type: Article
System: The UNT Digital Library
FINAL TECHNICAL REPORT: Request for support of the 11th Workshop on the Physics of Dusty Plasmas (open access)

FINAL TECHNICAL REPORT: Request for support of the 11th Workshop on the Physics of Dusty Plasmas

This grant supported the publication of student papers that were presented at the 11th Workshop on the Physics of Dusty Plasmas. Papers were published in a Special Issue of the IEEE Transactions on Plasma Science, Vol. 32, Issue 2 in April, 2007.
Date: May 21, 2009
Creator: Thomas, Edward
Object Type: Report
System: The UNT Digital Library