Theory of Microwave Instability and Coherent Synchrotron Radiation in Electron Storage Rings (open access)

Theory of Microwave Instability and Coherent Synchrotron Radiation in Electron Storage Rings

None
Date: December 10, 2012
Creator: Cai, Y
Object Type: Article
System: The UNT Digital Library
Genetically Modified Bacteria for Fuel Production (open access)

Genetically Modified Bacteria for Fuel Production

Advanced Research Projects Agency-Energy project sheet summarizing general information about the Electrofuels program including critical needs, innovation and advantages, impacts, and contact information. This sheet discusses a new program to develop a bacteria that uses electricity to convert carbon dioxide into liquid fuels as part of the "Development of Rhodobacter as a Versatile Platform for Fuels Production" project.
Date: May 10, 2012
Creator: Pennsylvania State University
Object Type: Text
System: The UNT Digital Library
Atmospheric Radiation Measurement Climate Research Facility Operations Quarterly Report July 1–September 30, 2012 (open access)

Atmospheric Radiation Measurement Climate Research Facility Operations Quarterly Report July 1–September 30, 2012

Individual datastreams from instrumentation at the Atmospheric Radiation Measurement (ARM) Climate Research Facility fixed and mobile research sites are collected and routed to the Data Management Facility (DMF) for processing in near-real-time. Instrument and processed data are then delivered approximately daily to the ARM Data Archive, where they are made freely available to the research community. For each instrument, we calculate the ratio of the actual number of processed data records received daily at the Data Archive to the expected number of data records. The results are tabulated by (1) individual datastream, site, and month for the current year and (2) site and fiscal year (FY) dating back to 1998.
Date: October 10, 2012
Creator: Voyles, JW
Object Type: Text
System: The UNT Digital Library
Improvement of snowpack simulations in a regional climate model (open access)

Improvement of snowpack simulations in a regional climate model

To improve simulations of regional-scale snow processes and related cold-season hydroclimate, the Community Land Model version 3 (CLM3), developed by the National Center for Atmospheric Research (NCAR), was coupled with the Pennsylvania State University/NCAR fifth-generation Mesoscale Model (MM5). CLM3 physically describes the mass and heat transfer within the snowpack using five snow layers that include liquid water and solid ice. The coupled MM5–CLM3 model performance was evaluated for the snowmelt season in the Columbia River Basin in the Pacific Northwestern United States using gridded temperature and precipitation observations, along with station observations. The results from MM5–CLM3 show a significant improvement in the SWE simulation, which has been underestimated in the original version of MM5 coupled with the Noah land-surface model. One important cause for the underestimated SWE in Noah is its unrealistic land-surface structure configuration where vegetation, snow and the topsoil layer are blended when snow is present. This study demonstrates the importance of the sheltering effects of the forest canopy on snow surface energy budgets, which is included in CLM3. Such effects are further seen in the simulations of surface air temperature and precipitation in regional weather and climate models such as MM5. In addition, the snow-season surface albedo …
Date: January 10, 2011
Creator: Jin, J. & Miller, N. L.
Object Type: Article
System: The UNT Digital Library
Element-specific study of epitaxial NiO/Ag/CoO/Fe films grown on vicinal Ag(001) using photoemission electron microscopy (open access)

Element-specific study of epitaxial NiO/Ag/CoO/Fe films grown on vicinal Ag(001) using photoemission electron microscopy

NiO/Ag/CoO/Fe single crystalline films are grown epitaxially on a vicinal Ag(001) substrate using molecular beam epitaxy and investigated by photoemission electron microscopy. We find that after zero-field cooling, the in-plane Fe magnetization switches from parallel to perpendicular direction of the atomic steps of the vicinal surface at thinner CoO thickness but remains in its original direction parallel to the steps at thicker CoO thickness. CoO and NiO domain imaging result shows that both CoO/Fe and NiO/CoO spins are perpendicularly coupled, suggesting that the Fe magnetization switching may be associated with the rotatable-frozen spin transition of the CoO film.
Date: January 10, 2011
Creator: Meng, Y.; Li, J.; Tan, A.; Jin, E.; Son, J.; Park, J. S. et al.
Object Type: Article
System: The UNT Digital Library
QCD Radiation in the Production of Heavy Colored Particles at the LHC (open access)

QCD Radiation in the Production of Heavy Colored Particles at the LHC

None
Date: July 10, 2013
Creator: Alwall, Johan; de Visscher, Simon & Maltoni, Fabio
Object Type: Article
System: The UNT Digital Library
BWR Anticipated Transients Without Scram Leading to Instability (open access)

BWR Anticipated Transients Without Scram Leading to Instability

Anticipated transients without scram (ATWS) in aboiling water reactor (BWR) were simulated in order to understand reactor response and determine the effectiveness of automatic and operator actions to mitigate this beyond-design-basis accident. The events of interest herein are initiated by a turbine trip when the reactor is operating in the expanded operating domainMELLLA+ [maximum extended load line limit plus]. In these events the reactor may initially be at up to 120% of the original licensed thermal power (OLTP) and at flow rates as low as 80% of rated.For these (and similar) ATWS events the concern isthat when the reactor power decreases in response to a dual recirculation pump trip, the core will become unstable and large amplitude oscillations will begin. The occurrence of these power oscillations, if left unmitigated, may result in fuel damage, and the amplitude of the poweroscillations may hamper the effectiveness of the injection of dissolved neutron absorber through the standby liquid control system (SLCS).
Date: November 10, 2013
Creator: Cheng, Lap-Yan; Baek, Joo-Seok; Cuadra, Arantxa; Aronson, Arnold; Diamond, David & Yarsky, Peter
Object Type: Article
System: The UNT Digital Library
Saltstone SDU6 Modeling Study (open access)

Saltstone SDU6 Modeling Study

A new disposal unit, designated as Saltstone Disposal Unit 6 (SDU6), is being designed for support of site accelerated closure goals and salt waste projections identified in the new Liquid Waste System Plan. The unit is a cylindrical disposal cell of 375 ft in diameter and 43 ft in height, and it has a minimum 30 million gallons of capacity. SRNL was requested to evaluate the impact of an increased grout placement height on the flow patterns radially spread on the floor and to determine whether grout quality is impacted by the height. The primary goals of the work are to develop the baseline Computational Fluid Dynamics (CFD) model and to perform the evaluations for the flow patterns of grout material in SDU6 as a function of elevation of grout discharge port and grout rheology. Two transient grout models have been developed by taking a three-dimensional multiphase CFD approach to estimate the domain size of the grout materials radially spread on the facility floor and to perform the sensitivity analysis with respect to the baseline design and operating conditions such as elevation height of the discharge port and fresh grout properties. For the CFD modeling calculations, air-grout Volume of Fluid …
Date: January 10, 2013
Creator: Lee, Si Y. & Hyun, Sinjae
Object Type: Report
System: The UNT Digital Library
Scalable Load Balancing for Massively Parallel Distributed Monte Carlo Particle Transport (open access)

Scalable Load Balancing for Massively Parallel Distributed Monte Carlo Particle Transport

None
Date: December 10, 2012
Creator: O'Brien, M. J.; Brantley, P. S. & Joy, K. I.
Object Type: Article
System: The UNT Digital Library
DEVELOPMENT OF THE HS99 AIR TRANSPORT TYPE A FISSILE PACKAGE (open access)

DEVELOPMENT OF THE HS99 AIR TRANSPORT TYPE A FISSILE PACKAGE

An air-transport Type A Fissile radioactive shipping package for the transport of special form uranium sources has been developed by the Savannah River National Laboratory (SRNL) for the Department of Homeland Security. The Package model number is HS99 for Homeland Security Model 99. This paper presents the major design features of the HS99 and highlights engineered materials necessary for meeting the design requirements for this light-weight Type AF packaging. A discussion is provided demonstrating how the HS99 complies with the regulatory safety requirements of the Nuclear Regulatory Commission. The paper summarizes the results of structural testing to specified in 10 CFR 71 for Normal Conditions of Transport and Hypothetical Accident Conditions events. Planned and proposed future missions for this packaging are also addressed.
Date: July 10, 2012
Creator: Blanton, P. & Eberl, K.
Object Type: Article
System: The UNT Digital Library
WILDFIRE IGNITION RESISTANCE ESTIMATOR WIZARD SOFTWARE DEVELOPMENT REPORT (open access)

WILDFIRE IGNITION RESISTANCE ESTIMATOR WIZARD SOFTWARE DEVELOPMENT REPORT

This report describes the development of a software tool, entitled “WildFire Ignition Resistance Estimator Wizard” (WildFIRE Wizard, Version 2.10). This software was developed within the Wildfire Ignition Resistant Home Design (WIRHD) program, sponsored by the U. S. Department of Homeland Security, Science and Technology Directorate, Infrastructure Protection & Disaster Management Division. WildFIRE Wizard is a tool that enables homeowners to take preventive actions that will reduce their home’s vulnerability to wildfire ignition sources (i.e., embers, radiant heat, and direct flame impingement) well in advance of a wildfire event. This report describes the development of the software, its operation, its technical basis and calculations, and steps taken to verify its performance.
Date: October 10, 2012
Creator: Phillips, M.; Robinson, C.; Gupta, N. & Werth, D.
Object Type: Report
System: The UNT Digital Library
Scharz Preconditioners for Krylov Methods: Theory and Practice (open access)

Scharz Preconditioners for Krylov Methods: Theory and Practice

Several numerical methods were produced and analyzed. The main thrust of the work relates to inexact Krylov subspace methods for the solution of linear systems of equations arising from the discretization of partial di#11;erential equa- tions. These are iterative methods, i.e., where an approximation is obtained and at each step. Usually, a matrix-vector product is needed at each iteration. In the inexact methods, this product (or the application of a preconditioner) can be done inexactly. Schwarz methods, based on domain decompositions, are excellent preconditioners for thise systems. We contributed towards their under- standing from an algebraic point of view, developed new ones, and studied their performance in the inexact setting. We also worked on combinatorial problems to help de#12;ne the algebraic partition of the domains, with the needed overlap, as well as PDE-constraint optimization using the above-mentioned inexact Krylov subspace methods.
Date: May 10, 2013
Creator: Szyld, Daniel B.
Object Type: Report
System: The UNT Digital Library
High Multiplicity W Jets Predictions at NLO (open access)

High Multiplicity W Jets Predictions at NLO

None
Date: September 10, 2013
Creator: Bern, Z.; Dixon, L.J.; Cordero, F.Febres; Hoche, S.; Ita, H.; Kosower, D.A. et al.
Object Type: Article
System: The UNT Digital Library
Reduction in Fabrication Costs of Gas Diffusion Layers (open access)

Reduction in Fabrication Costs of Gas Diffusion Layers

Ballard Material Products (BMP) performed a pre-design technical and cost analysis of state of the art production technologies feasible for high volume GDL manufacturing. Based upon criteria that also included environmental health and safety, customer quality requirements, and future needs, BMP selected technologies that can be integrated into its current manufacturing process. These selections included Many-At-A-Time (MAAT) coating and continuous mixing technologies, as well as various on-line process control tools. These processes have allowed BMP to produce high performance GDLs at lower cost for near-term markets, as well as to define the inputs needed to develop a conceptual Greenfield facility to meet the cost targets for automotive volumes of 500,000 vehicles per year.
Date: July 10, 2012
Creator: Morgan, Jason; Connors, Donald & Hickner, Michael
Object Type: Report
System: The UNT Digital Library
Closure Report (CR) for Corrective Action Unit (CAU) 91: Area 3 U-3fi Injection Well with Errata Sheet and Certification, Revision 0 (open access)

Closure Report (CR) for Corrective Action Unit (CAU) 91: Area 3 U-3fi Injection Well with Errata Sheet and Certification, Revision 0

The closure report for CAU 91 has no Use Restriction Form or drawing/map included in the document to describe the use restricted area, however, Section 3.3.3 states that the site will be fenced and signage placed indicating the area as a Resource Conservation and Recovery Act (RCRA) Unit. The drawing that was placed in the FFACO indicating the use restricted area lists the coordinates for the RCRA Unit in Nevada State Plan Coordinates - North American Datum of 1983. In the ensuing years the reporting of coordinates has been standardized so that all coordinates are reported in the same manner, which is: NAD 27 UTM Zone 11 N, meters. This Errata Sheet updates the coordinate reporting to the currently accepted method and includes an aerial photo showing the RCRA Unit with the coordinates listed showing the use restricted area.
Date: August 10, 2010
Creator: Services, Navarro Nevada Environmental
Object Type: Report
System: The UNT Digital Library
ACETYL-COA CLEAVAGE AND SYNTHESIS IN METHANOGENS; CHARACTERIZATION OF SUBOMPONENT INTERACTIONS IN THE ACETYL-COA DECARBONYLASE/SYNTHASE MULTIENZYME COMPLEX (open access)

ACETYL-COA CLEAVAGE AND SYNTHESIS IN METHANOGENS; CHARACTERIZATION OF SUBOMPONENT INTERACTIONS IN THE ACETYL-COA DECARBONYLASE/SYNTHASE MULTIENZYME COMPLEX

The work reported resulted in much new insight into unusual mechanisms of metalloenzymes involved in anaerobic metabolism in methanogens, other archaea, and bacteria.
Date: October 10, 2013
Creator: GRAHAM, DAVID A.
Object Type: Report
System: The UNT Digital Library
Analysis of International Policies In The Solar Electricity Sector: Lessons for India (open access)

Analysis of International Policies In The Solar Electricity Sector: Lessons for India

Although solar costs are dropping rapidly, solar power is still more expensive than conventional and other renewable energy options. The solar sector still needs continuing government policy support. These policies are driven by objectives that go beyond the goal of achieving grid parity. The need to achieve multiple objectives and ensure sufficient political support for solar power makes it diffi cult for policy makers to design the optimal solar power policy. The dynamic and uncertain nature of the solar industry, combined with the constraints offered by broader economic, political and social conditions further complicates the task of policy making. This report presents an analysis of solar promotion policies in seven countries - Germany, Spain, the United States, Japan, China, Taiwan, and India - in terms of their outlook, objectives, policy mechanisms and outcomes. The report presents key insights, primarily in qualitative terms, and recommendations for two distinct audiences. The first audience consists of global policy makers who are exploring various mechanisms to increase the penetration of solar power in markets to mitigate climate change. The second audience consists of key Indian policy makers who are developing a long-term implementation plan under the Jawaharlal Nehru National Solar Mission and various state …
Date: August 10, 2011
Creator: Deshmukh, Ranjit; Bharvirkar, Ranjit; Gambhir, Ashwin & Phadke, Amol
Object Type: Report
System: The UNT Digital Library
Final Technical Report for DUSEL Research and Development on Sub-Kelvin Germanium Detectors for Ton Scale Dark Matter Search (open access)

Final Technical Report for DUSEL Research and Development on Sub-Kelvin Germanium Detectors for Ton Scale Dark Matter Search

We have supported one graduate student and a small percentage of fabrication staff on $135k per year for three years plus one no cost extension year on this DUSEL R&D grant.  There were three themes within our research program: (1) how to improve the radial sensitivity for single sided phonon readout with four equal area sensors of which three form a central circle and fourth a surrounding ring; (2) how to instrument double sided phonon readouts which will give us better surface event rejection and increased fiducial volume for future CDMS style detectors; and (3) can we manufacture much larger Ge detectors using six inch diameter material which is not suitable for standard gamma ray spectroscopy.
Date: September 10, 2012
Creator: Cabrera, Prof. Blas
Object Type: Report
System: The UNT Digital Library
Sheet beam model for intense space-charge: with application to Debye screening and the distribution of particle oscillation frequencies in a thermal equilibrium beam (open access)

Sheet beam model for intense space-charge: with application to Debye screening and the distribution of particle oscillation frequencies in a thermal equilibrium beam

A one-dimensional Vlasov-Poisson model for sheet beams is reviewed and extended to provide a simple framework for analysis of space-charge effects. Centroid and rms envelope equations including image charge effects are derived and reasonable parameter equivalences with commonly employed 2D transverse models of unbunched beams are established. This sheet beam model is then applied to analyze several problems of fundamental interest. A sheet beam thermal equilibrium distribution in a continuous focusing channel is constructed and shown to have analogous properties to two- d three-dimensional thermal equilibrium models in terms of the equilibrium structure and Deybe screening properties. The simpler formulation for sheet beams is exploited to explicitly calculate the distribution of particle oscillation frequencies within a thermal equilibrium beam. It is shown that as space-charge intensity increases, the frequency distribution becomes broad, suggesting that beams with strong space-charge can have improved stability.
Date: January 10, 2011
Creator: Lund, Steven M.; Friedman, Alex & Bazouin, Guillaume
Object Type: Article
System: The UNT Digital Library
NIC Final Review November 13-14, 2012 (open access)

NIC Final Review November 13-14, 2012

None
Date: December 10, 2012
Creator: Nuckolls, J H
Object Type: Report
System: The UNT Digital Library
Camera assembly design proposal for SRF cavity image collection (open access)

Camera assembly design proposal for SRF cavity image collection

This project seeks to collect images from the inside of a superconducting radio frequency (SRF) large grain niobium cavity during vertical testing. These images will provide information on multipacting and other phenomena occurring in the SRF cavity during these tests. Multipacting, a process that involves an electron buildup in the cavity and concurrent loss of RF power, is thought to be occurring near the cathode in the SRF structure. Images of electron emission in the structure will help diagnose the source of multipacting in the cavity. Multipacting sources may be eliminated with an alteration of geometric or resonant conditions in the SRF structure. Other phenomena, including unexplained light emissions previously discovered at SLAC, may be present in the cavity. In order to effectively capture images of these events during testing, a camera assembly needs to be installed to the bottom of the RF structure. The SRF assembly operates under extreme environmental conditions: it is kept in a dewar in a bath of 2K liquid helium during these tests, is pumped down to ultra-high vacuum, and is subjected to RF voltages. Because of this, the camera needs to exist as a separate assembly attached to the bottom of the cavity. The …
Date: October 10, 2011
Creator: Tuozzolo, S.
Object Type: Report
System: The UNT Digital Library
Unintegrated sea quark at small x and vector boson production (open access)

Unintegrated sea quark at small x and vector boson production

N/A
Date: March 10, 2012
Creator: F., Hautmann; Hentschinski, M. & Jung, H.
Object Type: Article
System: The UNT Digital Library
Printability and inspectability of Defects on the EUV Mask for sub32nm Half Pitch HVM Application (open access)

Printability and inspectability of Defects on the EUV Mask for sub32nm Half Pitch HVM Application

The availability of defect-free masks remains one of the key challenges for inserting extreme ultraviolet lithography (EUVL) into high volume manufacturing, yet little data is available for understanding native defects on real masks. In this paper, a full field EUV mask is fabricated to see the printability of various defects on the mask. Programmed pit defect shows that minimum printable size of pits could be 17 nm of SEVD from the AIT. However 23.1nm in SEVD is printable from the EUV ADT. Defect printability and identification of its source along from blank fabrication to mask fabrication were studied using various inspection tools. Capture ratio of smallest printable defects was improved to 80% using optimized stack of metrical on wafer and state-of-art wafer inspection tool. Requirement of defect mitigation technology using fiducial mark are defined.
Date: January 10, 2011
Creator: Huh, S.; Kang, I. Y.; Kim, S. H.; Seo, H. S.; Kim, D.; Park, J. et al.
Object Type: Article
System: The UNT Digital Library
The Structure of Jets at Hadron Colliders (open access)

The Structure of Jets at Hadron Colliders

None
Date: August 10, 2012
Creator: Larkoski, Andrew James
Object Type: Thesis or Dissertation
System: The UNT Digital Library