States

Toward fully self-consistent simulation of the interaction of E-Clouds and beams with WARP-POSINST (open access)

Toward fully self-consistent simulation of the interaction of E-Clouds and beams with WARP-POSINST

To predict the evolution of electron clouds and their effect on the beam, the high energy physics community has relied so far on the complementary use of 'buildup' and 'single/multi-bunch instability' reduced descriptions. The former describes the evolution of electron clouds at a given location in the ring, or 'station', under the influence of prescribed beams and external fields [1], while the latter (sometimes also referred as the 'quasi-static' approximation [2]) follows the interaction between the beams and the electron clouds around the accelerator with prescribed initial distributions of electrons, assumed to be concentrated at a number of discrete 'stations' around the ring. Examples of single bunch instability codes include HEADTAIL [3], QuickPIC [4, 5], and PEHTS [6]. By contrast, a fully self-consistent approach, in which both the electron cloud and beam distributions evolve simultaneously under their mutual influence without any restriction on their relative motion, is required for modeling the interaction of high-intensity beams with electron clouds for heavy-ion beam-driven fusion and warm-dense matter science. This community has relied on the use of Particle-In-Cell (PIC) methods through the development and use of the WARP-POSINST code suite [1, 7, 8]. The development of novel numerical techniques (including adaptive mesh refinement, …
Date: April 9, 2012
Creator: Lawrence Livermore National Laboratory
Object Type: Article
System: The UNT Digital Library
2012 Computation Annual Report (open access)

2012 Computation Annual Report

None
Date: April 30, 2013
Creator: Crawford, D. L.
Object Type: Report
System: The UNT Digital Library
Development of ZnTe:Cu Contacts for CdTe Solar Cells: Cooperative Research and Development Final Report, CRADA Number CRD-08-320 (open access)

Development of ZnTe:Cu Contacts for CdTe Solar Cells: Cooperative Research and Development Final Report, CRADA Number CRD-08-320

The main focus of the work at NREL was on the development of Cu-doped ZnTe contacts to CdTe solar cells in the substrate configuration. The work performed under the CRADA utilized the substrate device structure used at NREL previously. All fabrication was performed at NREL. We worked on the development of Cu-doped ZnTe as well as variety of other contacts such as Sb-doped ZnTe, CuxTe, and MoSe2. We were able to optimize the contacts to improve device parameters. The improvement was obtained primarily through increasing the open-circuit voltage, to values as high as 760 mV, leading to device efficiencies of 7%.
Date: April 1, 2012
Creator: Dhere, R.
Object Type: Report
System: The UNT Digital Library
Delaware Energy and Cost Savings for New Single- and Multifamily Homes: 2012 IECC as Compared to the 2009 IECC (open access)

Delaware Energy and Cost Savings for New Single- and Multifamily Homes: 2012 IECC as Compared to the 2009 IECC

The 2012 International Energy Conservation Code (IECC) yields positive benefits for Delaware homeowners. Moving to the 2012 IECC from the 2009 IECC is cost effective over a 30-year life cycle. On average, Delaware homeowners will save $10,409 with the 2012 IECC. After accounting for upfront costs and additional costs financed in the mortgage, homeowners should see net positive cash flows (i.e., cumulative savings exceeding cumulative cash outlays) in 1 year for the 2012 IECC. Average annual energy savings are $616 for the 2012 IECC.
Date: April 1, 2012
Creator: Lucas, Robert G.; Taylor, Zachary T.; Mendon, Vrushali V. & Goel, Supriya
Object Type: Report
System: The UNT Digital Library
Influence of Translation Initiation on Organellar Protein Targeting in Arabidopsis (open access)

Influence of Translation Initiation on Organellar Protein Targeting in Arabidopsis

A primary focus of the Mackenzie laboratory is the elucidation of processes and machinery for mitochondrial genome maintenance and transmission in higher plants. We have found that numerous organellar DNA maintenance components in plants appear to be dual targeted to mitochondria and plastids. Of particular interest was the observation that some twin (tandemly arrayed) dual targeting presequences appeared to utilize non-AUG alternative translation initiation, allowing for multiple translation starts at a single gene. Two aspects of this phenomenon were of particular interest: (1) Alternative translation initiation might provide a mechanism to regulate protein targeting temporally and spatially, a possibility that had not been demonstrated previously, and (2) alternative translation initiation might occur in genes involved in nuclear-controlled mitochondrial genome recombination, thought to be exclusively mitochondrial in their function. During the course of this research, we pursued three aims, with an emphasis on two specific genes of interest: POLgamma2, an organellar DNA polymerase, and MSH1, a MutS homolog thought to participate in mitochondrial, but not plastid, genome recombination surveillance. Our aims were to (1) Identify additional genes within Arabidopsis and other genomes that employ non-AUG alternative translation initiation, (2) Locate sequences upstream to the annotated AUG that confer alternative non-AUG translation …
Date: April 18, 2011
Creator: Mackenzie, Sally A.
Object Type: Report
System: The UNT Digital Library
Molecular analysis of the metabolic rates of discrete subsurface populations of sulfate reducers (open access)

Molecular analysis of the metabolic rates of discrete subsurface populations of sulfate reducers

Elucidating the in situ metabolic activity of phylogenetically diverse populations of sulfate-reducing microorganisms that populate anoxic sedimentary environments is key to understanding subsurface ecology. Previous pure culture studies have demonstrated that transcript abundance of dissimilatory (bi)sulfite reductase genes is correlated with the sulfate reducing activity of individual cells. To evaluate whether expression of these genes was diagnostic for subsurface communities, dissimilatory (bi)sulfite reductase gene transcript abundance in phylogenetically distinct sulfate-reducing populations was quantified during a field experiment in which acetate was added to uranium-contaminated groundwater. Analysis of dsrAB sequences prior to the addition of acetate indicated that Desulfobacteraceae, Desulfobulbaceae, and Syntrophaceae-related sulfate reducers were the most abundant. Quantifying dsrB transcripts of the individual populations suggested that Desulfobacteraceae initially had higher dsrB transcripts per cell than Desulfobulbaceae or Syntrophaceae populations, and that the activity of Desulfobacteraceae increased further when the metabolism of dissimilatory metal reducers competing for the added acetate declined. In contrast, dsrB transcript abundance in Desulfobulbaceae and Syntrophaceae remained relatively constant, suggesting a lack of stimulation by added acetate. The indication of higher sulfate-reducing activity in the Desulfobacteraceae was consistent with the finding that Desulfobacteraceae became the predominant component of the sulfate-reducing community. Discontinuing acetate additions resulted in a …
Date: April 1, 2011
Creator: Miletto, M.; Williams, K.H.; N'Guessan, A.L. & Lovley, D.R.
Object Type: Article
System: The UNT Digital Library
NREL: A Year in Clean Energy Innovations: A Review of NREL's Feature Stories, 2010 (open access)

NREL: A Year in Clean Energy Innovations: A Review of NREL's Feature Stories, 2010

The publication is a compilation of various feature stories published on NREL's public website, nrel.gov, throughout Calendar Year 2010.
Date: April 1, 2011
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Measure Guideline: Transitioning from Three-Coat Stucco to One-Coat Stucco with EPS (open access)

Measure Guideline: Transitioning from Three-Coat Stucco to One-Coat Stucco with EPS

This Measure Guideline has been developed to help builders transition from using a traditional three-coat stucco wall-cladding system to a one-coat stucco wall-cladding system with expanded polystyrene (EPS) insulated sheathing. The three-coat system uses a base layer, a fill layer, and a finish layer. The one-coat system maintains the look of a traditional stucco system but uses only a base layer and a finish coat over EPS insulation that achieves higher levels of energy efficiency. Potential risks associated with the installation of a one-coat stucco system are addressed in terms of design, installation, and warranty concerns such as cracking and delamination, along with mitigation strategies to reduce these risks.
Date: April 1, 2012
Creator: Brozyna, K.; Davis, G. & Rapport, A.
Object Type: Report
System: The UNT Digital Library
Magnetic Alignment of Pulsed Solenoids Using the Pulsed Wire Method (open access)

Magnetic Alignment of Pulsed Solenoids Using the Pulsed Wire Method

A unique application of the pulsed-wire measurement method has been implemented for alignment of 2.5 T pulsed solenoid magnets. The magnetic axis measurement has been shown to have a resolution of better than 25 {micro}m. The accuracy of the technique allows for the identification of inherent field errors due to, for example, the winding layer transitions and the current leads. The alignment system is developed for the induction accelerator NDCX-II under construction at LBNL, an upgraded Neutralized Drift Compression experiment for research on warm dense matter and heavy ion fusion. Precise alignment is essential for NDCX-II, since the ion beam has a large energy spread associated with the rapid pulse compression such that misalignments lead to corkscrew deformation of the beam and reduced intensity at focus. The ability to align the magnetic axis of the pulsed solenoids to within 100 pm of the induction cell axis has been demonstrated.
Date: April 1, 2011
Creator: Arbelaez, D.; Madur, A.; Lipton, T. M.; Waldron, W. L. & Kwan, J. W.
Object Type: Article
System: The UNT Digital Library
Hydrogen Storage in Metal-Organic Frameworks (open access)

Hydrogen Storage in Metal-Organic Frameworks

Conventional storage of large amounts of hydrogen in its molecular form is difficult and expensive because it requires employing either extremely high pressure gas or very low temperature liquid. Because of the importance of hydrogen as a fuel, the DOE has set system targets for hydrogen storage of gravimetric (5.5 wt%) and volumetric (40 g L-1) densities to be achieved by 2015. Given that these are system goals, a practical material will need to have higher capacity when the weight of the tank and associated cooling or regeneration system is considered. The size and weight of these components will vary substantially depending on whether the material operates by a chemisorption or physisorption mechanism. In the latter case, metal-organic frameworks (MOFs) have recently been identified as promising adsorbents for hydrogen storage, although little data is available for their sorption behavior. This grant was focused on the study of MOFs with these specific objectives. (1) To examine the effects of functionalization, catenation, and variation of the metal oxide and organic linkers on the low-pressure hydrogen adsorption properties of MOFs. (2) To develop a strategy for producing MOFs with high surface area and porosity to reduce the dead space and increase the hydrogen …
Date: April 26, 2012
Creator: Yaghi, Omar M.
Object Type: Report
System: The UNT Digital Library
Max Tech and Beyond: High-Intensity Discharge Lamps (open access)

Max Tech and Beyond: High-Intensity Discharge Lamps

High-intensity discharge (HID) lamps are most often found in industrial and commercial applications, and are the light source of choice in street and area lighting, and sports stadium illumination. HID lamps are produced in three types - mercury vapor (MV), high pressure sodium (HPS) and metal halide (MH). Of these, MV and MH are considered white-light sources (although the MV exhibits poor color rendering) and HPS produces a yellow-orange color light. A fourth lamp, low-pressure sodium (LPS), is not a HID lamp by definition, but it is used in similar applications and thus is often grouped with HID lamps. With the notable exception of MV which is comparatively inefficient and in decline in the US from both a sales and installed stock point of view; HPS, LPS and MH all have efficacies over 100 lumens per watt. The figure below presents the efficacy trends over time for commercially available HID lamps and LPS, starting with MV and LPS in 1930's followed by the development of HPS and MH in the 1960's. In HID lamps, light is generated by creating an electric arc between two electrodes in an arc tube. The particles in the arc are partially ionized, making them electrically …
Date: April 1, 2012
Creator: Scholand, Michael
Object Type: Report
System: The UNT Digital Library
Developement of 3D Vertically Integrated Pattern Recognition Associative Memory (VIPRAM) (open access)

Developement of 3D Vertically Integrated Pattern Recognition Associative Memory (VIPRAM)

Many next-generation physics experiments will be characterized by the collection of large quantities of data, taken in rapid succession, from which scientists will have to unravel the underlying physical processes. In most cases, large backgrounds will overwhelm the physics signal. Since the quantity of data that can be stored for later analysis is limited, real-time event selection is imperative to retain the interesting events while rejecting the background. Scaling of current technologies is unlikely to satisfy the scientific needs of future projects, so investments in transformational new technologies need to be made. For example, future particle physics experiments looking for rare processes will have to address the demanding challenges of fast pattern recognition in triggering as detector hit density becomes significantly higher due to the high luminosity required to produce the rare processes. In this proposal, we intend to develop hardware-based technology that significantly advances the state-of-the-art for fast pattern recognition within and outside HEP using the 3D vertical integration technology that has emerged recently in industry. The ultimate physics reach of the LHC experiments will crucially depend on the tracking trigger's ability to help discriminate between interesting rare events and the background. Hardware-based pattern recognition for fast triggering on …
Date: April 13, 2011
Creator: Deputch, G.; Hoff, J.; Lipton, R.; Liu, T.; Olsen, J.; Ramberg, E. et al.
Object Type: Report
System: The UNT Digital Library
Collapsing Bubble in Metal for High Energy Density Physics Study (open access)

Collapsing Bubble in Metal for High Energy Density Physics Study

This paper presents a new idea to produce matter in the high energy density physics (HEDP) regime in the laboratory using an intense ion beam. A gas bubble created inside a solid metal may collapse by driving it with an intense ion beam. The melted metal will compress the gas bubble and supply extra energy to it. Simulations show that the spherical implosion ratio can be about 5 and at the stagnation point, the maximum density, temperature and pressure inside the gas bubble can go up to nearly 2 times solid density, 10 eV and a few megabar (Mbar) respectively. The proposed experiment is the first to permit access into the Mbar regime with existing or near-term ion facilities, and opens up possibilities for new physics gained through careful comparisons of simulations with measurements of quantities like stagnation radius, peak temperature and peak pressure at the metal wall.
Date: April 13, 2011
Creator: Ng, S. F.; Barnard, J. J.; Leung, P. T. & Yu, S. S.
Object Type: Article
System: The UNT Digital Library
Comparative genomics of citric-acid producing Aspergillus niger ATCC 1015 versus enzyme-producing CBS 513.88 (open access)

Comparative genomics of citric-acid producing Aspergillus niger ATCC 1015 versus enzyme-producing CBS 513.88

The filamentous fungus Aspergillus niger exhibits great diversity in its phenotype. It is found globally, both as marine and terrestrial strains, produces both organic acids and hydrolytic enzymes in high amounts, and some isolates exhibit pathogenicity. Although the genome of an industrial enzyme-producing A. niger strain (CBS 513.88) has already been sequenced, the versatility and diversity of this species compels additional exploration. We therefore undertook whole genome sequencing of the acidogenic A. niger wild type strain (ATCC 1015), and produced a genome sequence of very high quality. Only 15 gaps are present in the sequence and half the telomeric regions have been elucidated. Moreover, sequence information from ATCC 1015 was utilized to improve the genome sequence of CBS 513.88. Chromosome-level comparisons uncovered several genome rearrangements, deletions, a clear case of strain-specific horizontal gene transfer, and identification of 0.8 megabase of novel sequence. Single nucleotide polymorphisms per kilobase (SNPs/kb) between the two strains were found to be exceptionally high (average: 7.8, maximum: 160 SNPs/kb). High variation within the species was confirmed with exo-metabolite profiling and phylogenetics. Detailed lists of alleles were generated, and genotypic differences were observed to accumulate in metabolic pathways essential to acid production and protein synthesis. A transcriptome …
Date: April 28, 2011
Creator: Grigoriev, Igor V.; Baker, Scott E.; Andersen, Mikael R.; Salazar, Margarita P.; Schaap, Peter J.; Vondervoot, Peter J.I. van de et al.
Object Type: Article
System: The UNT Digital Library
Estimated Carbon Dioxide Emissions in 2008: United States (open access)

Estimated Carbon Dioxide Emissions in 2008: United States

Flow charts depicting carbon dioxide emissions in the United States have been constructed from publicly available data and estimates of state-level energy use patterns. Approximately 5,800 million metric tons of carbon dioxide were emitted throughout the United States for use in power production, residential, commercial, industrial, and transportation applications in 2008. Carbon dioxide is emitted from the use of three major energy resources: natural gas, coal, and petroleum. The flow patterns are represented in a compact 'visual atlas' of 52 state-level (all 50 states, the District of Columbia, and one national) carbon dioxide flow charts representing a comprehensive systems view of national CO{sub 2} emissions. Lawrence Livermore National Lab (LLNL) has published flow charts (also referred to as 'Sankey Diagrams') of important national commodities since the early 1970s. The most widely recognized of these charts is the U.S. energy flow chart (http://flowcharts.llnl.gov). LLNL has also published charts depicting carbon (or carbon dioxide potential) flow and water flow at the national level as well as energy, carbon, and water flows at the international, state, municipal, and organizational (i.e. United States Air Force) level. Flow charts are valuable as single-page references that contain quantitative data about resource, commodity, and byproduct flows in …
Date: April 1, 2011
Creator: Smith, C. A.; Simon, A. J. & Belles, R. D.
Object Type: Report
System: The UNT Digital Library
Efficient Multifamily Homes in a Hot-Humid Climate by Atlantic Housing Partners (open access)

Efficient Multifamily Homes in a Hot-Humid Climate by Atlantic Housing Partners

With assistance from the Florida Solar Energy Center (FSEC) and its Building America Partnership for Improved Residential Construction (BA-PIRC), Atlantic Housing Partners (AHP) has implemented a high performance, systems engineered package of measures. This report demonstrates how the initiative achieves Building America (BA) goals of 30%-50% energy savings. Specifically, the goals are documented as being achieved in the new construction multifamily housing sector in the hot humid climate. Results from energy modeling of the high performance package are presented. The role of utility allowance calculations, used as part of the low-income housing tax credit process, to value those energy savings is discussed, as is customer satisfaction with heat pump water heaters.
Date: April 1, 2013
Creator: Chasar, D. & Martin, E.
Object Type: Report
System: The UNT Digital Library
Feasibility Study of Economics and Performance of Solar Photovoltaics at the Brisbane Baylands Brownfield Site in Brisbane, California. (open access)

Feasibility Study of Economics and Performance of Solar Photovoltaics at the Brisbane Baylands Brownfield Site in Brisbane, California.

The U.S. Environmental Protection Agency (EPA), in accordance with the RE-Powering America's Land initiative, selected the Brisbane Baylands site in Brisbane, California, for a feasibility study of renewable energy production. The National Renewable Energy Laboratory (NREL) provided technical assistance for this project. The purpose of this report is to assess the site for a possible photovoltaic (PV) system installation and estimate the cost, performance, and site impacts of different PV options. In addition, the report recommends financing options that could assist in the implementation of a PV system at the site.
Date: April 1, 2013
Creator: Salasovich, J.; Geiger, J.; Healey, V. & Mosey, G.
Object Type: Report
System: The UNT Digital Library
Midlatitude Continental Convective Clouds Experiment (MC3E) (open access)

Midlatitude Continental Convective Clouds Experiment (MC3E)

The Midlatitude Continental Convective Clouds Experiment (MC3E) will take place in central Oklahoma during the April–May 2011 period. The experiment is a collaborative effort between the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility and the National Aeronautics and Space Administration’s (NASA) Global Precipitation Measurement (GPM) mission Ground Validation (GV) program. The field campaign leverages the unprecedented observing infrastructure currently available in the central United States, combined with an extensive sounding array, remote sensing and in situ aircraft observations, NASA GPM ground validation remote sensors, and new ARM instrumentation purchased with American Recovery and Reinvestment Act funding. The overarching goal is to provide the most complete characterization of convective cloud systems, precipitation, and the environment that has ever been obtained, providing constraints for model cumulus parameterizations and space-based rainfall retrieval algorithms over land that have never before been available.
Date: April 10, 2010
Creator: Jensen, M. P.; Petersen, W. A.; Del Genio, A. D.; Giangrande, S. E.; Heymsfield, A.; Heymsfield, G. et al.
Object Type: Report
System: The UNT Digital Library
In-Depth Look at Ground Source Heat Pumps and Other Electric Loads in Two GreenMax Homes (open access)

In-Depth Look at Ground Source Heat Pumps and Other Electric Loads in Two GreenMax Homes

CARB partnered with WPPI Energy to answer key research questions on in-field performance of ground-source heat pumps and LAMELs through extensive field monitoring at two WPPI GreenMax demonstration homes in Wisconsin. These two test home evaluations provided valuable data on the true in-field performance of various building mechanical systems and lighting, appliances, and miscellaneous loads (LAMELs).
Date: April 1, 2012
Creator: Puttagunta, S. & Shapiro, C.
Object Type: Report
System: The UNT Digital Library
Advanced Energy Design Guides Slash Energy Use in Schools and Retail Buildings by 50% (Fact Sheet) (open access)

Advanced Energy Design Guides Slash Energy Use in Schools and Retail Buildings by 50% (Fact Sheet)

Owners, contractors, engineers, and architects can easily achieve significant energy savings by leveraging the complex analyses and expertise captured in these guides.
Date: April 1, 2012
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Retail Buildings: Assessing and Reducing Plug and Process Loads in Retail Buildings (Fact Sheet) (open access)

Retail Buildings: Assessing and Reducing Plug and Process Loads in Retail Buildings (Fact Sheet)

Plug and process loads (PPLs) in commercial buildings account for almost 5% of U.S. primary energy consumption. Minimizing these loads is a primary challenge in the design and operation of an energy-efficient building. PPLs are not related to general lighting, heating, ventilation, cooling, and water heating, and typically do not provide comfort to the occupants. They use an increasingly large fraction of the building energy use pie because the number and variety of electrical devices have increased along with building system efficiency. Reducing PPLs is difficult because energy efficiency opportunities and the equipment needed to address PPL energy use in retail spaces are poorly understood.
Date: April 1, 2013
Creator: unknown
Object Type: Report
System: The UNT Digital Library
NREL Paves the Way to Commercialization of Silicon Ink (Fact Sheet) (open access)

NREL Paves the Way to Commercialization of Silicon Ink (Fact Sheet)

In 2008, Innovalight, a start-up company in Sunnyvale, California, invented a liquid form of silicon, called Silicon Ink. It contains silicon nanoparticles that are suspended evenly within the solution. Those nanoparticles contain dopant atoms that can be driven into silicon solar cells, which changes the conductivity of the silicon and creates the internal electric fields that are needed to turn photons into electrons -- and thus into electricity. The ink is applied with a standard screen printer, already commonly used in the solar industry. The distinguishing feature of Silicon Ink is that it can be distributed in exact concentrations in precisely the correct locations on the surface of the solar cell. This allows most of the surface to be lightly doped, enhancing its response to blue light, while heavily doping the area around the electrical contacts, raising the conductivity in that area to allow the contact to work more efficiently. The accuracy and uniformity of the ink distribution allows the production of solar cells that achieve higher power production at a minimal additional cost.
Date: April 1, 2012
Creator: unknown
Object Type: Report
System: The UNT Digital Library
IMPROVEMENT OF CdMnTe DETECTOR PERFORMANCE BY MnTe PURIFICATION (open access)

IMPROVEMENT OF CdMnTe DETECTOR PERFORMANCE BY MnTe PURIFICATION

Residual impurities in manganese (Mn) are a big obstacle to obtaining high-performance CdMnTe (CMT) X-ray and gamma-ray detectors. Generally, the zone-refining method is an effective way to improve the material's purity. In this work, we purified the MnTe compounds combining the zone-refining method with molten Te, which has a very high solubility for most impurities. We confirmed the improved purity of the material by glow-discharge mass spectrometry (GDMS). We also found that CMT crystals from a multiply-refined MnTe source, grown by the vertical Bridgman method, yielded better performing detectors.
Date: April 25, 2011
Creator: Kim, K. H.; Bolotnikov, A. E.; Camarda, G. S.; Tappero, R.; Hossain, A.; Cui, Y. et al.
Object Type: Article
System: The UNT Digital Library
Gearbox Reliability Collaborative: Test and Model Investigation of Sun Orbit and Planet Load Share in a Wind Turbine Gearbox; Preprint (open access)

Gearbox Reliability Collaborative: Test and Model Investigation of Sun Orbit and Planet Load Share in a Wind Turbine Gearbox; Preprint

This paper analyzes experimental measurement of the sun gear orbit in dynamometer testing and describes its relation to the other measured responses of the planetary stage. The relation of the sun orbit to component runout, component flexibility, gear coupling alignment, planet load share, and planet position error will be investigated. Equations describing the orbit of the sun gear in the test cases are derived. Rigid and flexible multibody models of the full gearbox are investigated and compared to sun and planet measurements. This paper shows that the sun gear's path may be influenced by gear coupling responses and gearbox structural flexibilities.
Date: April 1, 2012
Creator: LaCava, W.; Keller, J. & McNiff, B.
Object Type: Article
System: The UNT Digital Library