2012 ELECTRONIC PROCESSES IN ORGANIC MATERIALS GORDON RESEARCH SEMINAR, JUNE 2-8, 2012 (open access)

2012 ELECTRONIC PROCESSES IN ORGANIC MATERIALS GORDON RESEARCH SEMINAR, JUNE 2-8, 2012

This meeting focuses on the latest progress and challenges regarding organic electronics devices, artificial light-harvesting systems, and inorganic/organic hybrid nanoscale systems and especially on the synergy between these fields.
Date: June 8, 2012
Creator: Eisele, Dorthe
System: The UNT Digital Library
A 3D Particle Simulation Code for Heavy Ion Fusion Accelerator Studies (open access)

A 3D Particle Simulation Code for Heavy Ion Fusion Accelerator Studies

We describe WARP, a new particle-in-cell code being developed and optimized for ion beam studies in true geometry. We seek to model transport around bends, axial compression with strong focusing, multiple beamlet interaction, and other inherently 3d processes that affect emittance growth. Constraints imposed by memory and running time are severe. Thus, we employ only two 3d field arrays ({rho} and {phi}), and difference {phi} directly on each particle to get E, rather than interpolating E from three meshes; use of a single 3d array is feasible. A new method for PIC simulation of bent beams follows the beam particles in a family of rotated laboratory frames, thus straightening'' the bends. We are also incorporating an envelope calculation, an (r, z) model, and 1d (axial) model within WARP. The BASIS development and run-time system is used, providing a powerful interactive environment in which the user has access to all variables in the code database. 10 refs., 3 figs.
Date: June 8, 1990
Creator: Friedman, A.; Bangerter, R. O.; Callahan, D. A.; Grote, D. P.; Langdon, A. B. & Haber, I.
System: The UNT Digital Library
Adiabatic supernova expansion into the circumstellar medium (open access)

Adiabatic supernova expansion into the circumstellar medium

We perform one dimensional numerical simulations with a Lagrangian hydrodynamics code of the adiabatic expansion of a supernova into the surrounding medium. The early expansion follows Chevalier's analytic self-similar solution until the reverse shock reaches the ejecta core. We follow the expansion as it evolves towards the adiabatic blast wave phase. Some memory of the earlier phases of expansion is retained in the interior even when the outer regions expand as a blast wave. We find the results are sensitive to the initial configuration of the ejecta and to the placement of gridpoints. 6 refs., 2 figs.
Date: June 8, 1987
Creator: Band, D.L. & Liang, E.P.
System: The UNT Digital Library
Air Monitoring Leads to Discovery of New Contamination at Radioactive Waste Disposal Site (Area G) at LANL (open access)

Air Monitoring Leads to Discovery of New Contamination at Radioactive Waste Disposal Site (Area G) at LANL

Air monitoring at Area G, the low-level radioactive waste disposal area at Los Alamos National Laboratory, revealed increased air concentrations of {sup 239}Pu and {sup 241}Am at one location along the north boundary. This air monitoring location is a couple of meters north of a dirt road used to access the easternmost part of Area G. Air concentrations of {sup 238}Pu were essentially unaffected, which was puzzling because the {sup 238}Pu and {sup 239}Pu are present in the local, slightly contaminated soils. Air concentrations of these radionuclides increased about a factor of ten in early 1995 and remained at those levels until the first quarter of 1996. During the spring of 1996 air concentrations again increased by a factor of about ten. No other radionuclides were elevated and no other Area G stations showed elevations of these radionuclides. After several formal meetings didn't provide an adequate cause for the elevations, a gamma survey was performed and showed a small area of significant contamination just south of the monitor location. We found in February, 1995, a trench for a water line had been dug within a meter of so of the air stations. Then, during early 1996, the dirt road was …
Date: June 8, 1999
Creator: Kraig, David H. & Conrad, Ronald C.
System: The UNT Digital Library
Amplifying Real Estate Value through Energy&WaterManagement: From ESCO to 'Energy Services Partner' (open access)

Amplifying Real Estate Value through Energy&WaterManagement: From ESCO to 'Energy Services Partner'

The energy service company (ESCO) business model could become significantly more effective by integrating the energy-efficiency purveyor and their capital into the underlying building ownership and operation partnership, rather than the current model in which the ESCO remains an outsider with higher transaction costs and limited interest and participation in the value created by the cost savings. Resource conservation advocates rarely use the language of real estate to articulate the cost effectiveness of capital improvements aimed at reducing utility costs in commercial and residential income properties. Conventional methods that rely on rarefied academic notions of simple payback time or a narrow definition of return on investment fail to capture a significant component of the true market value created by virtue of reduced operating expenses. Improvements in energy and water efficiency can increase the fundamental profitability of real estate investments by raising Net Operating Income (NOI), and hence returns during the holding period, and, ultimately, proceeds at time of sale. We introduce the concept of an Energy Services Partner, who takes an equity interest in a real estate partnership in exchange for providing the expertise and capital required to reduce utility operating costs. Profit to all partners increases considerably as a …
Date: June 8, 2004
Creator: Mills, Evan
System: The UNT Digital Library
Annealing to Mitigate Pitting in Electropolished Niobium Coupons and SRF Cavities (open access)

Annealing to Mitigate Pitting in Electropolished Niobium Coupons and SRF Cavities

Ongoing studies at Fermilab investigate whether dislocations and other factors instigate pitting during cavity electropolishing (EP), despite careful processing controls and the inherent leveling mechanism of EP itself. Here, cold-worked niobium coupons, which exhibited increased tendencies for pitting in our past study, were annealed in a high vacuum furnace and subsequently processed by EP. Laser confocal scanning microscopy and special defect counting algorithms were used to assess the population of pits formed. Hardness measurements indicated that annealing for 2 hours at 800 C produced recovery, whereas annealing for 12 hours at 600 C did not, as is consistent with known changes for cavities annealed in a similar way. The 800 C anneal was effective in some cases but not others, and we discuss reasons why tendencies for pitting remain. We discuss implications for cavities and continued work to understand pitting.
Date: June 8, 2011
Creator: Cooley, L. D.; Hahn, E.; Hicks, D.; Romanenko, A.; Schuessler, R. & Thompson, C.
System: The UNT Digital Library
Antenna-coupled bolometer arrays using transition-edgesensors (open access)

Antenna-coupled bolometer arrays using transition-edgesensors

We describe the development of an antenna-coupled bolometer array for use in a Cosmic Microwave Background polarization experiment. Prototype single pixels using double-slot dipole antennas and integrated microstrip band defining filters have been built and tested. Preliminary results of optical testing and simulations are presented. A bolometer array design based on this pixel will also be shown and future plans for application of the technology will be discussed.
Date: June 8, 2004
Creator: Myers, Michael J.; Ade, Peter; Engargiola, Greg; Holzapfel,William; Lee,Adrian T.; O'Brient, Roger et al.
System: The UNT Digital Library
Argonne National Laboratory Expedited Site Characterization: First International Symposium on Integrated Technical Approaches to Site Characterization - Proceedings Volume (open access)

Argonne National Laboratory Expedited Site Characterization: First International Symposium on Integrated Technical Approaches to Site Characterization - Proceedings Volume

Laboratory applications for the analysis of PCBS (polychlorinated biphenyls) in environmental matrices such as soil/sediment/sludge and oil/waste oil were evaluated for potential reduction in waste, source reduction, and alternative techniques for final determination. As a consequence, new procedures were studied for solvent substitution, miniaturization of extraction and cleanups, minimization of reagent consumption, reduction of cost per analysis, and reduction of time. These new procedures provide adequate data that meet all the performance requirements for the determination of PCBS. Use of the new procedures reduced costs for all sample preparation techniques. Time and cost were also reduced by combining the new sample preparation procedures with the power of fast gas chromatography. Separation of Aroclor 1254 was achieved in less than 6 min by using DB-1 and SPB-608 columns. With the greatly shortened run times, reproducibility can be tested quickly and consequently with low cost. With performance-based methodology, the applications presented here can be applied now, without waiting for regulatory approval.
Date: June 8, 1998
Creator: unknown
System: The UNT Digital Library
Brillouin scatter in a hydrodynamic simulation (open access)

Brillouin scatter in a hydrodynamic simulation

A numerical method for modeling stimulated Brillouin scatter (SBS) in a hydrodynamic simulation code is discussed. Preliminary results using the model show that scattering is reduced as shorter wavelengths are used and for spherical symmetry that ion heating by SBS is not significant since the ions cool by expansion.
Date: June 8, 1979
Creator: Harte, J.; Estabrook, K. & Bailey, D.
System: The UNT Digital Library
CERTS Microgrid Laboratory Test Bed (open access)

CERTS Microgrid Laboratory Test Bed

The objective of the CERTS Microgrid Test Bed project was to enhance the ease of integrating energy sources into a microgrid. The project accomplished this objective by developing and demonstrating three advanced techniques, collectively referred to as the CERTS Microgrid concept, that significantly reduce the level of custom field engineering needed to operate microgrids consisting of generating sources less than 100kW. The techniques comprising the CERTS Microgrid concept are: 1 a method for effecting automatic and seamless transitions between grid-connected and islanded modes of operation, islanding the microgrid's load from a disturbance, thereby maintaining a higher level of service, without impacting the integrity of the utility's electrical power grid; 2 an approach to electrical protection within a limited source microgrid that does not depend on high fault currents; and 3 a method for microgrid control that achieves voltage and frequency stability under islanded conditions without requiring high-speed communications between sources.
Date: June 8, 2010
Creator: ETO, J.; LASSETER, R.; SCHENKMAN, B.; STEVENS, J.; KLAPP, D.; VOLKOMMER, H. et al.
System: The UNT Digital Library
CERTS Microgrid Laboratory Test Bed (open access)

CERTS Microgrid Laboratory Test Bed

CERTS Microgrid concept captures the emerging potential of distributed generation using a system approach. CERTS views generation and associated loads as a subsystem or a 'microgrid'. The sources can operate in parallel to the grid or can operate in island, providing UPS services. The system can disconnect from the utility during large events (i.e. faults, voltage collapses), but may also intentionally disconnect when the quality of power from the grid falls below certain standards. CERTS Microgrid concepts were demonstrated at a full-scale test bed built near Columbus, Ohio and operated by American Electric Power. The testing fully confirmed earlier research that had been conducted initially through analytical simulations, then through laboratory emulations, and finally through factory acceptance testing of individual microgrid components. The islanding and resynchronization method met all Institute of Electrical and Electronics Engineers Standard 1547 and power quality requirements. The electrical protection system was able to distinguish between normal and faulted operation. The controls were found to be robust under all conditions, including difficult motor starts and high impedance faults.
Date: June 8, 2010
Creator: Lasseter, R. H.; Eto, J. H.; Schenkman, B.; Stevens, J.; Volkmmer, H.; Klapp, D. et al.
System: The UNT Digital Library
Characterization and device performance of (AgCu)(InGa)Se2 absorber layers (open access)

Characterization and device performance of (AgCu)(InGa)Se2 absorber layers

The study of (AgCu)(InGa)Se2 absorber layers is of interest in that Ag-chalcopyrites exhibit both wider bandgaps and lower melting points than their Cu counterparts. (AgCu)(InGa)Se2 absorber layers were deposited over the composition range 0 < Ag/(Ag+Cu) < 1 and 0.3 < Ga/(In+Ga) < 1.0 using a variety of elemental co-evaporation processes. Films were found to be singlephase over the entire composition range, in contrast to prior studies. Devices with Ga content 0.3 < Ga/(In+Ga) <0.5 tolerated Ag incorporation up to Ag/(Ag+Cu) = 0.5 without appreciable performance loss. Ag-containing films with Ga/(In+Ga) = 0.8 showed improved device characteristics over Cu-only control samples, in particular a 30-40% increase in short-circuit current. An absorber layer with composition Ag/(Ag+Cu) = 0.75 and Ga/(In+Ga) = 0.8 yielded a device with VOC = 890 mV, JSC = 20.5mA/cm2, fill factor = 71.3%, and η = 13.0%.
Date: June 8, 2009
Creator: Hanket, Gregory; Boyle, Jonathan H. & Shafarman, William N.
System: The UNT Digital Library
Chemical dependence of interatomic x-ray transition energies and intensities - a study of Mn K beta '' and K beta 2,5 spectra (open access)

Chemical dependence of interatomic x-ray transition energies and intensities - a study of Mn K beta '' and K beta 2,5 spectra

None
Date: June 8, 2001
Creator: Bergmann, U.; Horne, C. R.; Collins, T. J.; Workman, J. M. & Cramer, S. P.
System: The UNT Digital Library
Cherenkov Radiation from e+e- Pairs and Its Effect on nu e InducedShowers (open access)

Cherenkov Radiation from e+e- Pairs and Its Effect on nu e InducedShowers

We calculate the Cherenkov radiation from an e{sup +}e{sup -} pair at small separations, as occurs shortly after a pair conversion. The radiation is reduced (compared to that from two independent particles) when the pair separation is smaller than the wavelength of the emitted light. We estimate the reduction in light in large electromagnetic showers, and discuss the implications for detectors that observe Cherenkov radiation from showers in the Earth's atmosphere, as well as in oceans and Antarctic ice.
Date: June 8, 2005
Creator: Mandal, Sourav K.; Klein, Spencer R. & Jackson, J. David
System: The UNT Digital Library
Computing derivatives of computer programs. (open access)

Computing derivatives of computer programs.

None
Date: June 8, 2000
Creator: Bischof, C. H. & Buecker, H. M.
System: The UNT Digital Library
Considerations for an active and passive scanner to assay nuclear waste drums (open access)

Considerations for an active and passive scanner to assay nuclear waste drums

Radioactive wastes are generated at many DOE laboratories, military facilities, fuel fabrication and enrichment plants, reactors, hospitals, and university research facilities. At all of these sites, wastes must be separated, packaged, categorized, and packed into some sort of container--usually 208-L (55-gal) drums--for shipment to waste-storage sites. Prior to shipment, the containers must be labeled, assayed, and certified; the assay value determines the ultimate disposition of the waste containers. An accurate nondestructive assay (NDA) method would identify all the radioisotopes present and provide a quantitative measurement of their activity in the drum. In this way, waste containers could be routed in the most cost-effective manner and without having to reopen them. Currently, the most common gamma-ray method used to assay nuclear waste drums is segmented gamma-ray scanning (SGS) spectrometer that crudely measures only the amount of {sup 235}U or {sup 239}Pu present in the drum. This method uses a spatially-averaged, integrated, emitted gamma-ray-intensity value. The emitted intensity value is corrected by an assumed constant-attenuation value determined by a spatially-averaged, transmission (or active) measurement. Unfortunately, this typically results in an inaccurate determination of the radioactive activities within a waste drum because this measurement technique is valid only for homogeneous-attenuation or known drum …
Date: June 8, 1990
Creator: Martz, H. E.; Azevedo, S. G.; Roberson, G. P.; Schneberk, D. J.; Koenig, Z. M. & Camp, D.C. (Lawrence Livermore National Lab., CA (USA))
System: The UNT Digital Library
Coupled CFD/CSM vibration design methodology for generation IV long-life fuel and component design. (open access)

Coupled CFD/CSM vibration design methodology for generation IV long-life fuel and component design.

None
Date: June 8, 2000
Creator: Weber, D. P.; Chen, S. S.; Wang, C. Y.; Wei, T. Y. C. & Jansson, S.
System: The UNT Digital Library
Coupling Visualization and Data Analysis for Knowledge Discovery from Multi-dimensional Scientific Data (open access)

Coupling Visualization and Data Analysis for Knowledge Discovery from Multi-dimensional Scientific Data

Knowledge discovery from large and complex scientific data is a challenging task. With the ability to measure and simulate more processes at increasingly finer spatial and temporal scales, the growing number of data dimensions and data objects presents tremendous challenges for effective data analysis and data exploration methods and tools. The combination and close integration of methods from scientific visualization, information visualization, automated data analysis, and other enabling technologies&quot;such as efficient data management&quot; supports knowledge discovery from multi-dimensional scientific data. This paper surveys two distinct applications in developmental biology and accelerator physics, illustrating the effectiveness of the described approach.
Date: June 8, 2010
Creator: Rubel, Oliver; Ahern, Sean; Bethel, E. Wes; Biggin, Mark D.; Childs, Hank; Cormier-Michel, Estelle et al.
System: The UNT Digital Library
Crystallization Process of Protein Rv0731c from Mycobacterium Tuberculosis for a Successful Atomic Resolution Crystal Structure at 1.2 Angstrom (open access)

Crystallization Process of Protein Rv0731c from Mycobacterium Tuberculosis for a Successful Atomic Resolution Crystal Structure at 1.2 Angstrom

Proteins are bio-macromolecules consisting of basic 20 amino acids and have distinct three-dimensional folds. They are essential parts of organisms and participate in every process within cells. Proteins are crucial for human life, and each protein within the body has a specific function, such as antibodies, contractile proteins, enzymes, hormonal proteins, structural proteins, storage proteins and transport proteins. Determining three-dimensional structure of a protein can help researchers discover the remarkable protein folding, binding site, conformation and etc, in order to understand well of protein interaction and aid for possible drug design. The research on protein structure by X-ray protein crystallography carried by Li-Wei Hung's research group in the Physical Bioscience Division at Lawrence Berkeley National Laboratory (LBNL) is focusing on protein crystallography. The research in this lab is in the process of from crystallizing the proteins to determining the three dimensional crystal structures of proteins. Most protein targets are selected from Mycobacterium Tuberculosis. TB (Tuberculosis) is a possible fatal infectious disease. By studying TB target protein can help discover antituberculer drugs, and find treatment for TB. The high-throughput mode of crystallization, crystal harvesting, crystal screening and data collection are applied to the research pipeline (Figure 1). The X-ray diffraction data …
Date: June 8, 2009
Creator: Zhu, Liang Cong
System: The UNT Digital Library
O-d energetics scaling models for Z-pinch-driven hohlraums (open access)

O-d energetics scaling models for Z-pinch-driven hohlraums

Wire array Z-pinches on the Z accelerator provide the most intense laboratory source of soft x-rays in the world. The unique combination of a highly-Planckian radiation source with high x-ray production efficiency (15% wall plug), large x-ray powers and energies ( &gt;150 TW, {ge}1 MJ in 7 ns), large characteristic hohlraum volumes (0.5 to &gt;10 cm{sup 3}), and long pulse-lengths (5 to 20 ns) may make Z-pinches a good match to the requirements for driving high-yield scale ICF capsules with adequate radiation symmetry and margin. The Z-pinch driven hohlraum approach of Hammer and Porter [Phys.Plasmas, 6, 2129(1999)] may provide a conservative and robust solution to the requirements for high yield, and is currently being studied on the Z accelerator. This paper describes a multiple region, 0-d hohlraum energetic model for Z-pinch driven hohlraums in four configurations. The authors observe consistency between the models and the measured x-ray powers and hohlraum wall temperatures to within {+-}20% in flux, for the four configurations.
Date: June 8, 2000
Creator: Cuneo, Michael E.; Vesey, Roger A.; Hammer, J. H. & Porter, John L.
System: The UNT Digital Library
Dependence of strength on particle size in graphite (open access)

Dependence of strength on particle size in graphite

The strength to particle size relationship for specially fabricated graphites has been demonstrated and rationalized using fracture mechanics. In the past, similar studies have yielded empirical data using only commercially available material. Thus, experimental verification of these relationships has been difficult. However, the graphites of this study were fabricated by controlling the particle size ranges for a series of isotropic graphites. All graphites that were evaluated had a constant 1.85 g/cm/sup 3/ density. Thus, particle size was the only variable. This study also considered the particle size effect on other physical properties; coefficient of thermal expansion (CTE), electrical resistivity, fracture strain, and Young's modulus.
Date: June 8, 1980
Creator: Kennedy, E. P. & Kennedy, C. R.
System: The UNT Digital Library
Design and Measurement of a Cu L-edge X-ray Filter for FEL-Pumped X-ray Laser Experiments (open access)

Design and Measurement of a Cu L-edge X-ray Filter for FEL-Pumped X-ray Laser Experiments

None
Date: June 8, 2010
Creator: Dunn, J.; London, R. A.; Cone, K. V.; Rocca, J. J. & Rohringer, N.
System: The UNT Digital Library
Design of a High Field Stress, Velvet Cathode for the Flash X-Ray (FXR) Induction Accelerator (open access)

Design of a High Field Stress, Velvet Cathode for the Flash X-Ray (FXR) Induction Accelerator

A new cathode design has been proposed for the Flash X-Ray (FXR) induction linear accelerator with the goal of lowering the beam emittance. The original design uses a conventional Pierce geometry and applies a peak field of 134 kV/cm (no beam) to the velvet emission surface. Voltage/current measurements indicate that the velvet begins emitting near this peak field value and images of the cathode show a very non-uniform distribution of plasma light. The new design has a flat cathode/shroud profile that allows for a peak field stress of 230 kV/cm on the velvet. The emission area is reduced by about a factor of four to generate the same total current due to the greater field stress. The relatively fast acceleration of the beam, approximately 2.5 MeV in 10 cm, reduces space charge forces that tend to hollow the beam for a flat, non-Pierce geometry. The higher field stress achieved with the same rise time is expected to lead to an earlier and more uniform plasma formation over the velvet surface. Simulations and initial testing are presented.
Date: June 8, 2007
Creator: Houck, T.; Brown, C.; Fleming, D.; Kreitzer, B.; Lewis, K.; Ong, M. et al.
System: The UNT Digital Library
Detecting data and schema changes in scientific documents (open access)

Detecting data and schema changes in scientific documents

Data stored in a data warehouse must be kept consistent and up-to-date with the underlying information sources. By providing the capability to identify, categorize and detect changes in these sources, only the modified data needs to be transferred and entered into the warehouse. Another alternative, periodically reloading from scratch, is obviously inefficient. When the schema of an information source changes, all components that interact with, or make use of, data originating from that source must be updated to conform to the new schema. In this paper, the authors present an approach to detecting data and schema changes in scientific documents. Scientific data is of particular interest because it is normally stored as semi-structured documents, and it incurs frequent schema updates. They address the change detection problem by detecting data and schema changes between two versions of the same semi-structured document. This paper presents a graph representation of semi-structured documents and their schema before describing their approach to detecting changes while parsing the document. It also discusses how analysis of a collection of schema changes obtained from comparing several individual can be used to detect complex schema changes.
Date: June 8, 1999
Creator: Adiwijaya, I; Critchlow, T & Musick, R
System: The UNT Digital Library