High Resolution PET with 250 micrometer LSO Detectors and Adaptive Zoom (open access)

High Resolution PET with 250 micrometer LSO Detectors and Adaptive Zoom

There have been impressive improvements in the performance of small-animal positron emission tomography (PET) systems since their first development in the mid 1990s, both in terms of spatial resolution and sensitivity, which have directly contributed to the increasing adoption of this technology for a wide range of biomedical applications. Nonetheless, current systems still are largely dominated by the size of the scintillator elements used in the detector. Our research predicts that developing scintillator arrays with an element size of 250 {micro}m or smaller will lead to an image resolution of 500 {micro}m when using 18F- or 64Cu-labeled radiotracers, giving a factor of 4-8 improvement in volumetric resolution over the highest resolution research systems currently in existence. This proposal had two main objectives: (i) To develop and evaluate much higher resolution and efficiency scintillator arrays that can be used in the future as the basis for detectors in a small-animal PET scanner where the spatial resolution is dominated by decay and interaction physics rather than detector size. (ii) To optimize one such high resolution, high sensitivity detector and adaptively integrate it into the existing microPET II small animal PET scanner as a 'zoom-in' detector that provides higher spatial resolution and sensitivity …
Date: January 8, 2012
Creator: Cherry, Simon R. & Qi, Jinyi
Object Type: Report
System: The UNT Digital Library
Analysis of Scalable Data-Privatization Threading Algorithms for Hybrid MPI/OpenMP Parallelization of Molecular Dynamics (open access)

Analysis of Scalable Data-Privatization Threading Algorithms for Hybrid MPI/OpenMP Parallelization of Molecular Dynamics

None
Date: February 8, 2012
Creator: Kunaseth, M.; Richards, D. F.; Glosli, J. N.; Kalia, R. K.; Nakano, A. & Vashista, P.
Object Type: Article
System: The UNT Digital Library
Controlled Hydrogen Fleet and Infrastructure Demonstration and Validation Project (open access)

Controlled Hydrogen Fleet and Infrastructure Demonstration and Validation Project

General Motors, LLC and energy partner Shell Hydrogen, LLC, deployed a system of hydrogen fuel cell electric vehicles integrated with a hydrogen fueling station infrastructure to operate under real world conditions as part of the U.S. Department of Energy's Controlled Hydrogen Fleet and Infrastructure Validation and Demonstration Project. This technical report documents the performance and describes the learnings from progressive generations of vehicle fuel cell system technology and multiple approaches to hydrogen generation and delivery for vehicle fueling.
Date: February 8, 2012
Creator: Stottler, Gary
Object Type: Report
System: The UNT Digital Library
High-Performance Computing for Electric Grid Planning and Operations (open access)

High-Performance Computing for Electric Grid Planning and Operations

None
Date: February 8, 2012
Creator: Epperly, T W; Edmunds, T; Lamont, A; Meyers, C; Smith, S; Yao, Y et al.
Object Type: Article
System: The UNT Digital Library
Life-Cycle Analysis Results for Geothermal Systems in Comparison to Other Power Systems: Part II. (open access)

Life-Cycle Analysis Results for Geothermal Systems in Comparison to Other Power Systems: Part II.

A study has been conducted on the material demand and life-cycle energy and emissions performance of power-generating technologies in addition to those reported in Part I of this series. The additional technologies included concentrated solar power, integrated gasification combined cycle, and a fossil/renewable (termed hybrid) geothermal technology, more specifically, co-produced gas and electric power plants from geo-pressured gas and electric (GPGE) sites. For the latter, two cases were considered: gas and electricity export and electricity-only export. Also modeled were cement, steel and diesel fuel requirements for drilling geothermal wells as a function of well depth. The impact of the construction activities in the building of plants was also estimated. The results of this study are consistent with previously reported trends found in Part I of this series. Among all the technologies considered, fossil combustion-based power plants have the lowest material demand for their construction and composition. On the other hand, conventional fossil-based power technologies have the highest greenhouse gas (GHG) emissions, followed by the hybrid and then two of the renewable power systems, namely hydrothermal flash power and biomass-based combustion power. GHG emissions from U.S. geothermal flash plants were also discussed, estimates provided, and data needs identified. Of the GPGE …
Date: February 8, 2012
Creator: Sullivan, J.L.; Clark, C.E.; Yuan, L.; Han, J. & Wang, M. (Energy Systems)
Object Type: Report
System: The UNT Digital Library
Lithium Ion Cell Development for Photovoltaic Energy Storage Applications (open access)

Lithium Ion Cell Development for Photovoltaic Energy Storage Applications

The overall project goal is to reduce the cost of home and neighborhood photovoltaic storage systems by reducing the single largest cost component – the energy storage cells. Solar power is accepted as an environmentally advantaged renewable power source. Its deployment in small communities and integrated into the grid, requires a safe, reliable and low cost energy storage system. The incumbent technology of lead acid cells is large, toxic to produce and dispose of, and offer limited life even with significant maintenance. The ideal PV storage battery would have the safety and low cost of lead acid but the performance of lithium ion chemistry. Present lithium ion batteries have the desired performance but cost and safety remain the two key implementation barriers. The purpose of this project is to develop new lithium ion cells that can meet PVES cost and safety requirements using A123Systems phosphate-based cathode chemistries in commercial PHEV cell formats. The cost target is a cell design for a home or neighborhood scale at <$25/kWh. This DOE program is the continuation and expansion of an initial MPSC (Michigan Public Service Commission) program towards this goal. This program further pushes the initial limits of some aspects of the original …
Date: February 8, 2012
Creator: Babinec, Susan
Object Type: Report
System: The UNT Digital Library
RECOVERY ACT: MULTIMODAL IMAGING FOR SOLAR CELL MICROCRACK DETECTION (open access)

RECOVERY ACT: MULTIMODAL IMAGING FOR SOLAR CELL MICROCRACK DETECTION

Undetected microcracks in solar cells are a principal cause of failure in service due to subsequent weather exposure, mechanical flexing or diurnal temperature cycles. Existing methods have not been able to detect cracks early enough in the production cycle to prevent inadvertent shipment to customers. This program, sponsored under the DOE Photovoltaic Supply Chain and Cross-Cutting Technologies program, studied the feasibility of quantifying surface micro-discontinuities by use of a novel technique, thermoreflectance imaging, to detect surface temperature gradients with very high spatial resolution, in combination with a suite of conventional imaging methods such as electroluminescence. The project carried out laboratory tests together with computational image analyses using sample solar cells with known defects supplied by industry sources or DOE National Labs. Quantitative comparisons between the effectiveness of the new technique and conventional methods were determined in terms of the smallest detectable crack. Also the robustness of the new technique for reliable microcrack detection was determined at various stages of processing such as before and after antireflectance treatments. An overall assessment is that the new technique compares favorably with existing methods such as lock-in thermography or ultrasonics. The project was 100% completed in Sept, 2010. A detailed report of key findings …
Date: February 8, 2012
Creator: Hudgings, Janice & Domash, Lawrence
Object Type: Report
System: The UNT Digital Library
2012 MULTIPHOTON PROCESSES GRC, JUNE 3-8, 2012 (open access)

2012 MULTIPHOTON PROCESSES GRC, JUNE 3-8, 2012

The sessions will focus on:  Attosecond science;  Strong-field processes in molecules and solids;  Generation of harmonics and attosecond pulses;  Free-electron laser experiments and theory;  Ultrafast imaging;  Applications of very high intensity lasers;  Propagation of intense laser fields.
Date: March 8, 2012
Creator: Walker, Barry
Object Type: Article
System: The UNT Digital Library
EVALUATION OF FABRIC MEMBRANES FOR USE IN SALTSTONE DRAIN WATER SYSTEM (open access)

EVALUATION OF FABRIC MEMBRANES FOR USE IN SALTSTONE DRAIN WATER SYSTEM

Saltstone Disposal Unit 2 contains a sheet drain fabric intended to separate solids from drain water to be returned to the Salt Feed Tank. A similar system installed in Vault 4 appears to be ineffective in keeping solids out of the drain water return lines. Waste Solidification Engineering is considering installation of an additional fabric membrane to supplement the existing sheet drain in SDU 2. Amerdrain 200 is the product currently installed in SDU 2. This product is no longer available, so Sitedrain 94 was used as the replacement product in this testing. Fabrics with apparent opening sizes of 10, 25, 50 and 100 microns were evaluated. These fabrics were evaluated under three separate test conditions, a water flow test, a solids retention test and a grout pour test. A flow test with water showed that installation of an additional filter layer will predictably reduce the theoretical flux through the sheet drain. The manufacturer reports the flux for Sitedrain 94 as 150 gpm/ft{sup 2} by ASTM D-4491. This compares reasonably well with the 117 gpm/ft{sup 2} obtained in this testing. A combination of the 10 micron fabric with Sitedrain 94 could be expected to decrease flux by about 10 times …
Date: March 8, 2012
Creator: Pickenheim, B.; Miller, D. & Burket, P.
Object Type: Report
System: The UNT Digital Library
Particle Size-Dependent Photoelectron Plasmon Loss Features In Deposited Germanium Nanocrystals (open access)

Particle Size-Dependent Photoelectron Plasmon Loss Features In Deposited Germanium Nanocrystals

None
Date: March 8, 2012
Creator: Bostedt, C; Willey, T; Terminello, L & van Buuren, T
Object Type: Article
System: The UNT Digital Library
Postmortem Cost and Schedule Analysis - Lessons Learned On NCSX (open access)

Postmortem Cost and Schedule Analysis - Lessons Learned On NCSX

The National Compact Stellarator Experiment (NCSX) was designed to test physics principles of an innovative fusion energy confinement device developed by the Princeton Plasma Physics Laboratory (PPPL) and Oak Ridge National Laboratory (ORNL) under contract from the US Department of Energy. The project was technically very challenging, primarily due to the complex component geometries and tight tolerances that were required. As the project matured these challenges manifested themselves in significant cost overruns through all phases of the project (i.e. design, R&amp;D, fabrication and assembly). The project was subsequently cancelled by the DOE in 2008. Although the project was not completed, several major work packages, comprising about 65% of the total estimated cost (excluding management and contingency), were completed, providing a data base of actual costs that can be analyzed to understand cost drivers. Technical factors that drove costs included the complex geometry, tight tolerances, material requirements, and performance requirements. Management factors included imposed annual funding constraints that throttled project cash flow, staff availability, and inadequate R&amp;D. Understanding how requirements and design decisions drove cost through this top-down forensic cost analysis could provide valuable insight into the configuration and design of future state-of-the art machines and other devices.
Date: March 8, 2012
Creator: R. Strykowsky, T. Brown, J. Chrzanowski, M. Cole, P. Heitzenroeder, G.H. Neilson, Donald Rej, and M. Viola
Object Type: Article
System: The UNT Digital Library
Proceedings of RIKEN BNL Research Center Workshop: Hyperon-Hyperon Interactions and Searches for Exotic Di-Hyperons in Nuclear Collisions (open access)

Proceedings of RIKEN BNL Research Center Workshop: Hyperon-Hyperon Interactions and Searches for Exotic Di-Hyperons in Nuclear Collisions

N/A
Date: March 8, 2012
Creator: J., Baltz A.; Fries, R.; Huang, H. Z.; Millener, J. & Xu, Z.
Object Type: Report
System: The UNT Digital Library
Requested Documentation Associated with Soil Sampling at Building 419 (open access)

Requested Documentation Associated with Soil Sampling at Building 419

None
Date: March 8, 2012
Creator: Salvo, V
Object Type: Report
System: The UNT Digital Library
SCANNING ELECTRON MICROSCOPY AND X-RAY DIFFRACTION ANALYSIS OF TANK 18 SAMPLES (open access)

SCANNING ELECTRON MICROSCOPY AND X-RAY DIFFRACTION ANALYSIS OF TANK 18 SAMPLES

The F-Area Tank Farm (FTF) Performance Assessment (PA) utilizes waste speciation in the waste release model used in the FTF fate and transport modeling. The waste release modeling associated with the residual plutonium in Tank 18 has been identified as a primary contributor to the Tank 18 dose uncertainty. In order to reduce the uncertainty related to plutonium in Tank 18, a better understanding of the plutonium speciation in the Tank 18 waste (including the oxidation state and stoichiometry) is desired. Savannah River National Laboratory (SRNL) utilized Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) to analyze Tank 18 samples to provide information on the speciation of plutonium in the waste material. XRD analysis of the Tank 18 samples did not identify any plutonium mineral phases in the samples. These indicates the crystalline mineral phases of plutonium are below the detection limits of the XRD method or that the plutonium phase(s) lack long range order and are present as amorphous or microcrystalline solids. SEM analysis of the Tank 18 samples did locate particles containing plutonium. The plutonium was found as small particles, usually &lt;1 {micro}m but ranging up to several micrometers in diameter, associated with particles of an iron matrix …
Date: March 8, 2012
Creator: Hay, M.; O'Rourke, P. & Ajo, H.
Object Type: Report
System: The UNT Digital Library
A systematic investigation of PET Radionuclide Specific Activity on Miniaturization of Radiochemistry (open access)

A systematic investigation of PET Radionuclide Specific Activity on Miniaturization of Radiochemistry

The PET radionuclides, 18F and 11C consist of very high radiation to mass amounts and should be easily adapted to new technologies such as “chip chemistry” with nanofluidics. However, environmental contamination with nonradioactive fluorine, carbon and other trace contaminants add sufficient mass, micrograms to milligrams, to prevent adapting PET radiochemistry to the nanochip technologies. In addition, the large volumes of material required for beam irradiation make it necessary to also remove the 18F and 11C from their chemical matrices. These steps add contaminants. The work described in this report was a systematic investigation of sources of these contaminants and methods to reduce these contaminants and the reaction volumes for radiochemical synthesis. Several methods were found to lower the contaminants and matrices to within a factor of 2 to 100 of those needed to fully implement chip technology but further improvements are needed.
Date: March 8, 2012
Creator: Link, Jeanne M.
Object Type: Report
System: The UNT Digital Library
Ultra-Compact High-Efficiency Luminaire for General Illumination (open access)

Ultra-Compact High-Efficiency Luminaire for General Illumination

Cree has developed a new ultra-compact light emitting diode (LED) luminaire capable of providing high efficacy with excellent color quality that can lead to significant energy savings in today‟s commercial and retail applications. This success was based on an integrated development effort tailoring the LED component characteristics, optics, thermal management and driver design for the small footprint to achieve an overall system efficiency of ≥ 70%. A new LED component was designed to provide high brightness and efficacy in a form factor that allowed for a small directional beam with a luminaire housing design able to dissipate the heat effectively using a small physical envelope. A very compact, 90% efficient driver was developed to meet the system performance while not taking away any thermal mass from the heat sink. A 91% efficient secondary optics was designed to maximize efficiency while providing a smooth beam. The reliability of the new LED component was robust under accelerated testing conditions. Luminaires were assembled integrating the novel LED component, secondary optics, heat sink and driver technology to demonstrate the system improvement. Cree has successfully completed this project by developing an ultra-compact LED luminaire that provided 380 lumens at a correlated color temperature (CCT) of …
Date: April 8, 2012
Creator: Lowes, Ted
Object Type: Report
System: The UNT Digital Library
Advanced Power Electronics for LED Drivers (open access)

Advanced Power Electronics for LED Drivers

Advanced Research Projects Agency-Energy project sheet summarizing general information about the Agile Delivery of Electrical Power Technology (ADEPT) program including critical needs, innovation and advantages, impacts, and contact information. This sheet discusses advanced power electronics for LED drivers as part of the "Advanced Technologies for Integrated Power Electronics" project.
Date: May 8, 2012
Creator: Massachusetts Institute of Technology
Object Type: Text
System: The UNT Digital Library
COLLABORATIVE RESEARCH: CONTINUOUS DYNAMIC GRID ADAPTATION IN A GLOBAL ATMOSPHERIC MODEL: APPLICATION AND REFINEMENT (open access)

COLLABORATIVE RESEARCH: CONTINUOUS DYNAMIC GRID ADAPTATION IN A GLOBAL ATMOSPHERIC MODEL: APPLICATION AND REFINEMENT

This project had goals of advancing the performance capabilities of the numerical general circulation model EULAG and using it to produce a fully operational atmospheric global climate model (AGCM) that can employ either static or dynamic grid stretching for targeted phenomena. The resulting AGCM combined EULAG's advanced dynamics core with the "physics" of the NCAR Community Atmospheric Model (CAM). Effort discussed below shows how we improved model performance and tested both EULAG and the coupled CAM-EULAG in several ways to demonstrate the grid stretching and ability to simulate very well a wide range of scales, that is, multi-scale capability. We leveraged our effort through interaction with an international EULAG community that has collectively developed new features and applications of EULAG, which we exploited for our own work summarized here. Overall, the work contributed to over 40 peer-reviewed publications and over 70 conference/workshop/seminar presentations, many of them invited. 3a. EULAG Advances EULAG is a non-hydrostatic, parallel computational model for all-scale geophysical flows. EULAG's name derives from its two computational options: EULerian (flux form) or semi-LAGrangian (advective form). The model combines nonoscillatory forward-in-time (NFT) numerical algorithms with a robust elliptic Krylov solver. A signature feature of EULAG is that it is formulated …
Date: May 8, 2012
Creator: Gutowski, William J.; Prusa, Joseph M. & Smolarkiewicz, Piotr K.
Object Type: Report
System: The UNT Digital Library
Compact, Interactive Electric Vehicle Charger (open access)

Compact, Interactive Electric Vehicle Charger

Advanced Research Projects Agency-Energy project sheet summarizing general information about the Agile Delivery of Electrical Power Technology (ADEPT) program including critical needs, innovation and advantages, impacts, and contact information. This sheet discusses a battery-to-grid energy distribution design as part of the "Gallium-Nitride Switch Technology for Bi-Directional Battery-to-Grid Charger Applications" project.
Date: May 8, 2012
Creator: HRL Laboratories, LLC
Object Type: Text
System: The UNT Digital Library
Comparison of ELM heat loads in snowflake and standard divertors (open access)

Comparison of ELM heat loads in snowflake and standard divertors

An analysis is given of the impact of the tokamak divertor magnetic structure on the temporal and spatial divertor heat flux from edge localized modes (ELMs). Two configurations are studied: the standard divertor where the poloidal magnetic field (B{sub p}) varies linearly with distance (r) from the magnetic null and the snowflake where B{sub p} varies quadratrically with r. Both one and two-dimensional models are used to analyze the effect of the longer magnetic field length between the midplane and the divertor plate for the snowflake that causes a temporal dilation of the ELM divertor heat flux. A second effect discussed is the appearance of a broad region near the null point where the poloidal plasma beta can substantially exceed unity, especially for the snowflake configuration during the ELM; such a condition is likely to drive additional radial ELM transport.
Date: May 8, 2012
Creator: Rognlien, T. D.; Cohen, R. H.; Ryutov, D. D. & Umansky, M. V.
Object Type: Article
System: The UNT Digital Library
Final Technical Report (open access)

Final Technical Report

Hackensack University Medical Center's major initiative to create a cleaner healthier and safer environment for patients, employees and the community served by the medical center is built on its commitment to protect the environment and conserve precious energy resources. Since 2004 the Medical Center launched a long term campaign to temper the negative environmental impact of proposed and existing new construction at the medical center and to improve campus wide overall energy efficiency. The plan was to begin by implementing a number of innovative and eco-friendly enhancements to the Gabrellian Women's and Children's Pavilion, in construction at the time, which would lead to Certification by the US Green Building Councils Leadership & Environmental Design (LEED) program. In addition the medical center would evaluate the feasibility of implementing a photovoltaic system in the new construction (in development and planned) to provide clean pollution free electricity. The steps taken to achieve this included conducting a feasibility study complete with architectural and engineering assessments to determine the potential for implementation of a photovoltaic system on the campus and also to conduct an energy survey that would focus on determining specific opportunities and upgrades that would lead to a healthier energy efficient interior environment …
Date: May 8, 2012
Creator: Cunning, Helen
Object Type: Report
System: The UNT Digital Library
GEOCHEMICAL MODELING OF F AREA SEEPAGE BASIN COMPOSITION AND VARIABILITY (open access)

GEOCHEMICAL MODELING OF F AREA SEEPAGE BASIN COMPOSITION AND VARIABILITY

From the 1950s through 1989, the F Area Seepage Basins at the Savannah River Site (SRS) received low level radioactive wastes resulting from processing nuclear materials. Discharges of process wastes to the F Area Seepage Basins followed by subsequent mixing processes within the basins and eventual infiltration into the subsurface resulted in contamination of the underlying vadose zone and downgradient groundwater. For simulating contaminant behavior and subsurface transport, a quantitative understanding of the interrelated discharge-mixing-infiltration system along with the resulting chemistry of fluids entering the subsurface is needed. An example of this need emerged as the F Area Seepage Basins was selected as a key case study demonstration site for the Advanced Simulation Capability for Environmental Management (ASCEM) Program. This modeling evaluation explored the importance of the wide variability in bulk wastewater chemistry as it propagated through the basins. The results are intended to generally improve and refine the conceptualization of infiltration of chemical wastes from seepage basins receiving variable waste streams and to specifically support the ASCEM case study model for the F Area Seepage Basins. Specific goals of this work included: (1) develop a technically-based 'charge-balanced' nominal source term chemistry for water infiltrating into the subsurface during basin …
Date: May 8, 2012
Creator: Millings, M.; Denham, M. & Looney, B.
Object Type: Report
System: The UNT Digital Library
In-Plane Electronic Anisotropy of Underdoped ___122___ Fe-Arsenide Superconductors Revealed by Measurements of Detwinned Single Crystals (open access)

In-Plane Electronic Anisotropy of Underdoped ___122___ Fe-Arsenide Superconductors Revealed by Measurements of Detwinned Single Crystals

The parent phases of the Fe-arsenide superconductors harbor an antiferromagnetic ground state. Significantly, the Neel transition is either preceded or accompanied by a structural transition that breaks the four fold symmetry of the high-temperature lattice. Borrowing language from the field of soft condensed matter physics, this broken discrete rotational symmetry is widely referred to as an Ising nematic phase transition. Understanding the origin of this effect is a key component of a complete theoretical description of the occurrence of superconductivity in this family of compounds, motivating both theoretical and experimental investigation of the nematic transition and the associated in-plane anisotropy. Here we review recent experimental progress in determining the intrinsic in-plane electronic anisotropy as revealed by resistivity, reflectivity and ARPES measurements of detwinned single crystals of underdoped Fe arsenide superconductors in the '122' family of compounds.
Date: May 8, 2012
Creator: Fisher, Ian Randal
Object Type: Article
System: The UNT Digital Library
INDEPENDENT VERIFICATION OF THE BUILDING 3550 SLAB AT OAK RIDGE NATIONAL LABORATORY OAK RIDGE, TENNESSEE (open access)

INDEPENDENT VERIFICATION OF THE BUILDING 3550 SLAB AT OAK RIDGE NATIONAL LABORATORY OAK RIDGE, TENNESSEE

The Oak Ridge Institute for Science and Education (ORISE) has completed the independent verification survey of the Building 3550 Slab. The results of this effort are provided. The objective of this verification survey is to provide independent review and field assessment of remediation actions conducted by Safety and Ecology Corporation (SEC) to document that the final radiological condition of the slab meets the release guidelines. Verification survey activities on the Building 3550 Slab that included scans, measurements, and the collection of smears. Scans for alpha, alpha plus beta, and gamma activity identified several areas that were investigated.
Date: May 8, 2012
Creator: Weaver, Phyllis C.
Object Type: Report
System: The UNT Digital Library