Cost-Effective Silicon Wafers for Solar Cells (open access)

Cost-Effective Silicon Wafers for Solar Cells

Advanced Research Projects Agency-Energy project sheet summarizing general information about a new program for hydrogen fuel cell vehicles (project title "Direct Wafer Enabling Terawatt Photovoltaics") including critical needs, innovation and advantages, impacts, and contact information. This sheet is the first open solicitation, announcing funding opportunities for involvement in the project.
Date: May 11, 2012
Creator: 1366 Technologies, Inc.
Object Type: Text
System: The UNT Digital Library
Engineering Enzymes in Energy Crops (open access)

Engineering Enzymes in Energy Crops

Advanced Research Projects Agency-Energy project sheet summarizing general information about a new program to engineer plants to produce enzymes that will reduce costs in the production of biofuel (project title "Conditionally Activated Enzymes Expressed in Cellulosic Energy Crops") including critical needs, innovation and advantages, impacts, and contact information. This sheet is the first open solicitation, announcing funding opportunities for involvement in the project.
Date: May 11, 2012
Creator: Agrivdia
Object Type: Text
System: The UNT Digital Library
Fuel From Algae (open access)

Fuel From Algae

Advanced Research Projects Agency-Energy project sheet summarizing general information about a new program to efficiently separate micro-solids from water (project title "Scaling and Commercialization of Algae Harvesting Technologies") including critical needs, innovation and advantages, impacts, and contact information. This sheet is the first open solicitation, announcing funding opportunities for involvement in the project.
Date: May 11, 2012
Creator: Algaeventure Systems
Object Type: Text
System: The UNT Digital Library
ELIMINATION OF THE CHARACTERIZATION OF DWPF POUR STREAM SAMPLE AND THE GLASS FABRICATION AND TESTING OF THE DWPF SLUDGE BATCH QUALIFICATION SAMPLE (open access)

ELIMINATION OF THE CHARACTERIZATION OF DWPF POUR STREAM SAMPLE AND THE GLASS FABRICATION AND TESTING OF THE DWPF SLUDGE BATCH QUALIFICATION SAMPLE

A recommendation to eliminate all characterization of pour stream glass samples and the glass fabrication and Product Consistency Test (PCT) of the sludge batch qualification sample was made by a Six-Sigma team chartered to eliminate non-value-added activities for the Defense Waste Processing Facility (DWPF) sludge batch qualification program and is documented in the report SS-PIP-2006-00030. That recommendation was supported through a technical data review by the Savannah River National Laboratory (SRNL) and is documented in the memorandums SRNL-PSE-2007-00079 and SRNL-PSE-2007-00080. At the time of writing those memorandums, the DWPF was processing sludge-only waste but, has since transitioned to a coupled operation (sludge and salt). The SRNL was recently tasked to perform a similar data review relevant to coupled operations and re-evaluate the previous recommendations. This report evaluates the validity of eliminating the characterization of pour stream glass samples and the glass fabrication and Product Consistency Test (PCT) of the sludge batch qualification samples based on sludge-only and coupled operations. The pour stream sample has confirmed the DWPF's ability to produce an acceptable waste form from Slurry Mix Evaporator (SME) blending and product composition/durability predictions for the previous sixteen years but, ultimately the pour stream analysis has added minimal value to …
Date: May 11, 2012
Creator: Amoroso, J.; Peeler, D. & Edwards, T.
Object Type: Report
System: The UNT Digital Library
Advanced High-Speed Framing Camera Development for Fast, Visible Imaging Experiments (open access)

Advanced High-Speed Framing Camera Development for Fast, Visible Imaging Experiments

The advances in high-voltage switching developed in this project allow a camera user to rapidly vary the number of output frames from 1 to 25. A high-voltage, variable-amplitude pulse train shifts the deflection location to the new frame location during the interlude between frames, making multiple frame counts and locations possible. The final deflection circuit deflects to five different frame positions per axis, including the center position, making for a total of 25 frames. To create the preset voltages, electronically adjustable {+-}500 V power supplies were chosen. Digital-to-analog converters provide digital control of the supplies. The power supplies are clamped to {+-}400 V so as not to exceed the voltage ratings of the transistors. A field-programmable gated array (FPGA) receives the trigger signal and calculates the combination of plate voltages for each frame. The interframe time and number of frames are specified by the user, but are limited by the camera electronics. The variable-frame circuit shifts the plate voltages of the first frame to those of the second frame during the user-specified interframe time. Designed around an electrostatic image tube, a framing camera images the light present during each frame (at the photocathode) onto the tube’s phosphor. The phosphor persistence …
Date: May 11, 2011
Creator: Amy Lewis, Stuart Baker, Brian Cox, Abel Diaz, David Glass, Matthew Martin
Object Type: Article
System: The UNT Digital Library
Dynamically Adjustable Wind Turbine Blades (open access)

Dynamically Adjustable Wind Turbine Blades

Advanced Research Projects Agency-Energy project sheet summarizing general information about a new program to develop wind turbines with more efficient control systems (project title "Adaptive Turbine Blades: Blown Wing Technology for Low-Cost Wind Power") including critical needs, innovation and advantages, impacts, and contract information. This sheet is the first open solicitation, announcing funding opportunities for involvement in the project.
Date: May 11, 2012
Creator: Caitin Inc.
Object Type: Text
System: The UNT Digital Library
Absence of Debye Sheaths Due to Secondary Electron Emission (open access)

Absence of Debye Sheaths Due to Secondary Electron Emission

A bounded plasma where the hot electrons impacting the walls produce more than one secondary on average is studied via particle-in-cell simulation. It is found that no classical Debye sheath or space-charge limited sheath exists. Ions are not drawn to the walls and electrons are not repelled. Hence the unconfined plasma electrons travel unobstructed to the walls, causing extreme particle and energy fluxes. Each wall has a positive charge, forming a small potential barrier or "inverse sheath" that pulls some secondaries back to the wall to maintain the zero current condition.
Date: May 11, 2012
Creator: Campanell, M. D.; Khabrov, A. & Kaganovich, I. D.
Object Type: Report
System: The UNT Digital Library
An imaging proton spectrometer for short-pulse laser plasma experiments (open access)

An imaging proton spectrometer for short-pulse laser plasma experiments

Ultra intense short pulse laser pulses incident on solid targets can generate energetic protons. In additions to their potentially important applications such as in cancer treatments and proton fast ignition, these protons are essential to understand the complex physics of intense laser plasma interaction. To better characterize these laser-produced protons, we designed and constructed a novel, spatially imaging proton spectrometer that will not only measure proton energy distribution with high resolution, but also provide its angular characteristics. The information obtained from this spectrometer compliments those from commonly used diagnostics including radiochromic film packs, CR39 nuclear track detectors, and non-imaging magnetic spectrometers. The basic characterizations and sample data from this instrument are presented.
Date: May 11, 2010
Creator: Chen, H.; Hazi, A.; van Maren, R.; Chen, S.; Fuchs, J.; Gauthier, M. et al.
Object Type: Article
System: The UNT Digital Library
The Energy Spectrum of Atmospheric Neutrinos between 2 and 200 TeV with the AMANDA-II Detector (open access)

The Energy Spectrum of Atmospheric Neutrinos between 2 and 200 TeV with the AMANDA-II Detector

The muon and anti-muon neutrino energy spectrum is determined from 2000-2003 AMANDA telescope data using regularised unfolding. This is the first measurement of atmospheric neutrinos in the energy range 2-200 TeV. The result is compared to different atmospheric neutrino models and it is compatible with the atmospheric neutrinos from pion and kaon decays. No significant contribution from charm hadron decays or extraterrestrial neutrinos is detected. The capabilities to improve the measurement of the neutrino spectrum with the successor experiment IceCube are discussed.
Date: May 11, 2010
Creator: Collaboration, IceCube & Abbasi, R.
Object Type: Article
System: The UNT Digital Library
Extinction and ecological retreat in a community of primates (open access)

Extinction and ecological retreat in a community of primates

None
Date: May 11, 2012
Creator: Crowley, B. E.; Godfrey, L. R.; Guilderson, T. P.; Zermeno, P.; Koch, P. L. & Dominy, N.
Object Type: Article
System: The UNT Digital Library
Dehumidifying Air for Cooling & Refrigeration (open access)

Dehumidifying Air for Cooling & Refrigeration

Advanced Research Projects Agency-Energy project sheet summarizing general information about a new program for hydrogen fuel cell vehicles (project title "Nanotechnology Membrane-based Dehumidifier") including critical needs, innovation and advantages, impacts, and contact information. This sheet is the first open solicitation, announcing funding opportunities for involvement in the project.
Date: May 11, 2012
Creator: Dais Analytical Corporation
Object Type: Text
System: The UNT Digital Library
Department of Energy DE-FG02-05ER25686 Early Career Principal Investigator Award Final Report (open access)

Department of Energy DE-FG02-05ER25686 Early Career Principal Investigator Award Final Report

This project is researching FAST, a methodology to build very fast, cycleaccurate full system computer simulators and building the first set of such simulators and the first set of tools to help construct those simulators. The methodology relies on a functional model that is a fast, full-system but not cycle-accurate simulator coupled with a timing model that is models the micro-architectural structure and arbitration of a computer system, but not its functionality. The way FAST simulators differ from other simulators partitioned in the same way is that the interface between the functional and timing model is optimized to minimize the need for round-trip communication. The optimized communication enables FAST timing models to be implemented in an FPGA and the functional model in software while still achieving extremely high performance. Our general strategy is to design a methodology and then prototype an example using that methodology to ensure the methodology is sound before committing to it. This strategy ensures that the selected methodology has been tested and provides an early example of the output of that methodology.
Date: May 11, 2013
Creator: Derek, Chiou
Object Type: Report
System: The UNT Digital Library
Accelerators for Intensity Frontier Research (open access)

Accelerators for Intensity Frontier Research

In 2008, the Particle Physics Project Prioritization Panel identified three frontiers for research in high energy physics, the Energy Frontier, the Intensity Frontier, and the Cosmic Frontier. In this paper, I will describe how Fermilab is configuring and upgrading the accelerator complex, prior to the development of Project X, in support of the Intensity Frontier.
Date: May 11, 2012
Creator: Derwent, Paul
Object Type: Article
System: The UNT Digital Library
HPCS Productivity Study - Compiler Analysis Summary (open access)

HPCS Productivity Study - Compiler Analysis Summary

None
Date: May 11, 2011
Creator: Dube, E & Chan, B
Object Type: Report
System: The UNT Digital Library
MacroAlgae Butanol (open access)

MacroAlgae Butanol

Advanced Research Projects Agency-Energy project sheet summarizing general information about a new program formacroalgae aquafaming to increase feedstock and biofuels (project title "MacroAlgae Butanol") including critical needs, innovation and advantages, impacts, and contact information. This sheet is the first open solicitation, announcing funding opportunities for involvement in the project.
Date: May 11, 2012
Creator: E.I. du Pont de Nemours & Company
Object Type: Text
System: The UNT Digital Library
Line-of-sight measurements for the NIF Neutron Imaging System and determination of line-of-sight offsets in OPAS 90-135 images (open access)

Line-of-sight measurements for the NIF Neutron Imaging System and determination of line-of-sight offsets in OPAS 90-135 images

None
Date: May 11, 2011
Creator: Frank, M; Fittinghoff, D N; Bower, D E; Drury, O B; Dzenitis, J M; Buckles, R A et al.
Object Type: Report
System: The UNT Digital Library
Computational Modeling and Assessment Of Nanocoatings for Ultra Supercritical Boilers (open access)

Computational Modeling and Assessment Of Nanocoatings for Ultra Supercritical Boilers

Coal-fired power plants are a significant part of the nation's power generating capacity, currently accounting for more than 55% of the country's total electricity production. Extending the reliable lifetimes of fossil fired boiler components and reducing the maintenance costs are essential for economic operation of power plants. Corrosion and erosion are leading causes of superheater and reheater boiler tube failures leading to unscheduled costly outages. Several types of coatings and weld overlays have been used to extend the service life of boiler tubes; however, the protection afforded by such materials was limited approximately one to eight years. Power companies are more recently focused in achieving greater plant efficiency by increasing steam temperature and pressure into the advanced-ultrasupercritical (A-USC) condition with steam temperatures approaching 760°C (1400°F) and operating pressures in excess of 35MPa (5075 psig). Unfortunately, laboratory and field testing suggests that the resultant fireside environment when operating under A-USC conditions can potentially cause significant corrosion to conventional and advanced boiler materials1-2. In order to improve reliability and availability of fossil fired A-USC boilers, it is essential to develop advanced nanostructured coatings that provide excellent corrosion and erosion resistance without adversely affecting the other properties such as toughness and thermal fatigue …
Date: May 11, 2011
Creator: Gandy, David W. & Shingledecker, John P.
Object Type: Text
System: The UNT Digital Library
LHC Abort Gap Cleaning Studies During Luminosity Operation (open access)

LHC Abort Gap Cleaning Studies During Luminosity Operation

The presence of significant intensities of un-bunched beam is a potentially serious issue in the LHC. Procedures using damper kickers for cleaning both the Abort Gap (AG) and the buckets targeted for injection, are currently in operation at flat bottom. Recent observations of relatively high population of the AG during physics runs brought up the need for AG cleaning during luminosity operation. In this paper the results of experimental studies performed in October 2011 are presented.
Date: May 11, 2012
Creator: Gianfelice-Wendt, E.; Bartmann, W.; Boccardi, A.; Bracco, C.; Bravin, E.; Goddard, B. et al.
Object Type: Article
System: The UNT Digital Library
A Drive Laser for Multi-Bunch Photoinjector Operation (open access)

A Drive Laser for Multi-Bunch Photoinjector Operation

Numerous electron beam applications would benefit from increased average current without sacrificing beam brightness. Work is underway at LLNL to investigate the performance of X-band photoinjectors that would generate electron bunches at a rate matching the RF drive frequency, i.e. one bunch per RF cycle. A critical part of this effort involves development of photo-cathode drive laser technology. Here we present a new laser architecture that can generate pulse trains at repetition rates up to several GHz. This compact, fiber-based system is driven directly by the accelerator RF and so is inherently synchronized with the accelerating fields, and scales readily over a wide range of drive frequencies (L-band through X-band). The system will be required to produce 0.5 {mu}J, {approx}200 fs rise time, spatially and temporally shaped UV pulses designed to optimize the electron beam brightness. Presented is the current status of this system, producing 2 ps pulses from a continuous-wave source.
Date: May 11, 2012
Creator: Gibson, D J; Cormier, E; Messerly, M J; Prantil, M A & Barty, C J
Object Type: Article
System: The UNT Digital Library
EVALUATION OF LOCAL STRAIN EVOLUTION FROM METALLIC WHISKER FORMATION (open access)

EVALUATION OF LOCAL STRAIN EVOLUTION FROM METALLIC WHISKER FORMATION

Evolution of local strain on electrodeposited tin films upon aging has been monitored by digital image correlation (DIC) for the first time. Maps of principal strains adjacent to whisker locations were constructed via comparing pre- and post-growth scanning electron microscopy (SEM) images. Results showed that the magnitude of the strain gradient plays an important role in whisker growth. DIC visualized the dynamic growth process in which the alteration of strain field has been identified to cause growth of subsequent whiskers.
Date: May 11, 2011
Creator: Hoffman, E. & Lam, P.
Object Type: Article
System: The UNT Digital Library
REPORT ON QUALITATIVE VALIDATION EXPERIMENTS USING LITHIUM-ALUMINUM LAYERED DOUBLE-HYDROXIDES FOR THE REDUCTION OF ALUMINUM FROM THE WASTE TREATMENT PLANT FEEDSTOCK (open access)

REPORT ON QUALITATIVE VALIDATION EXPERIMENTS USING LITHIUM-ALUMINUM LAYERED DOUBLE-HYDROXIDES FOR THE REDUCTION OF ALUMINUM FROM THE WASTE TREATMENT PLANT FEEDSTOCK

A process for removing aluminum from tank waste simulants by adding lithium and precipitating Li-Al-dihydroxide (Lithiumhydrotalcite, [LiAl{sub 2}(OH){sub 6}]{sup +}X{sup -}) has been verified. The tests involved a double-shell tank (DST) simulant and a single-shell tank (SST) simulant. In the case of the DST simulant, the product was the anticipated Li-hydrotalcite. For the SST simulant, the product formed was primarily Li-phosphate. However, adding excess Li to the solution did result in the formation of traces of Li-hydrotalcite. The Li-hydrotalcite from the DST supernate was an easily filterable solid. After four water washes the filter cake was a fluffy white material made of < 100 {micro}m particles made of smaller spheres. These spheres are agglomerates of {approx} 5 {micro}m diameter platelets with < 1 {micro}m thickness. Chemical and mineralogical analyses of the filtrate, filter cake, and wash waters indicate a removal of 90+ wt% of the dissolved Al for the DST simulant. For the SST simulant, the main competing reaction to the formation of lithium hydrotalcite appears to be the formation of lithium phosphate. In case of the DST simulant, phosphorus co-precipitated with the hydrotalcite. This would imply the added benefit of the removal of phosphorus along with aluminum in the …
Date: May 11, 2010
Creator: Huber, H. J.; Duncan, J. B. & Cooke, G. A.
Object Type: Report
System: The UNT Digital Library
An Enhanced Nonlinear Critical Gradient for Electron Turbulent Transport due to Reversed Magnetic Shear (open access)

An Enhanced Nonlinear Critical Gradient for Electron Turbulent Transport due to Reversed Magnetic Shear

The first nonlinear gyrokinetic simulations of electron internal transport barriers (e-ITBs) in the National Spherical Torus Experiment show that reversed magnetic shear can suppress thermal transport by increasing the nonlinear critical gradient for electron-temperature-gradient-driven turbulence to three times its linear critical value. An interesting feature of this turbulence is non- linearly driven off-midplane radial streamers. This work reinforces the experimental observation that magnetic shear is likely an effective way of triggering and sustaining e-ITBs in magnetic fusion devices.
Date: May 11, 2011
Creator: J. L. Peterson, G.W. Hammett, D.R. Mikkelsen, H.Y. Yuh, J. Candy, W. Guttenfelder, S.M. Kaye, and B. LeBlanc
Object Type: Report
System: The UNT Digital Library
Nanoheterostructure Cation Exchange: Anionic Framework Conservation (open access)

Nanoheterostructure Cation Exchange: Anionic Framework Conservation

In ionic nanocrystals the cationic sub-lattice can be replaced with a different metal ion via a fast, simple, and reversible place-exchange, allowing post-synthetic modification of the composition of the nanocrystal, while preserving its size and shape. Here, we demonstrate for the first time that during such an exchange, the anionic framework of the crystal is preserved. When applied to nanoheterostructures, this phenomenon ensures that compositional interfaces within the heterostructure are conserved throughout the transformation. For instance, a morphology composed of a CdSe nanocrystal embedded in a CdS rod (CdSe/CdS) was exchanged to a PbSe/PbS nanorod via a Cu2Se/Cu2S structure. During every exchange cycle, the seed size and position within the nanorod were preserved, as evident by excitonic features, Z-contrast imaging, and elemental line-scans. Anionic framework conservation extends the domain of cation exchange to the design of more complex and unique nanostructures.
Date: May 11, 2010
Creator: Jain, Prashant K.; Amirav, Lilac; Aloni, Shaul & Alivisatos, A. Paul
Object Type: Article
System: The UNT Digital Library
MicroCantilever (MC) based nanomechanical sensor for detection of molecular interactions (open access)

MicroCantilever (MC) based nanomechanical sensor for detection of molecular interactions

Specific aims of this study are to investigate the mechanism governing surface stress generation associated with chemical or molecular binding on functionalized microcantilevers. Formation of affinity complexes on cantilever surfaces leads to charge redistribution, configurational change and steric hindrance between neighboring molecules resulting in surface stress change and measureable cantilever deformation. A novel interferometry technique employing two adjacent micromachined cantilevers (a sensing/reference pair) was utilized to measure the cantilever deformation. The sensing principle is that binding/reaction of specific chemical or biological species on the sensing cantilever transduces to mechanical deformation. The differential bending of the sensing cantilever respect to the reference cantilever ensures that measured response is insensitive to environmental disturbances. As a proof of principle for the measurement technique, surface stress changes associated with: self-assembly of alkanethiol, hybridization of ssDNA, and the formation of cocaine-aptamer complexes were measured. Dissociation constant (K{sub d}) for each molecular reaction was utilized to estimate the surface coverage of affinity complexes. In the cases of DNA hybridization and cocaine-aptamer binding, measured surface stress was found to be dependent on the surface coverage of the affinity complexes. In order to achieve a better sensitivity for DNA hybridization, immobilization of receptor molecules was modified to enhance …
Date: May 11, 2011
Creator: Kang, Kyung
Object Type: Thesis or Dissertation
System: The UNT Digital Library