Tunable Diode Laser Absorption Spectroscopy Using a Multi-Pass White Cell for O2 Detection (open access)

Tunable Diode Laser Absorption Spectroscopy Using a Multi-Pass White Cell for O2 Detection

None
Date: August 8, 2012
Creator: Raval, M.; Bora, M.; McCarrick, J. & Bond, T.
Object Type: Report
System: The UNT Digital Library
TAGGING, TRACKING AND LOCATING WITHOUT GPS (open access)

TAGGING, TRACKING AND LOCATING WITHOUT GPS

The Savannah River National Laboratory (SRNL) was requested to lead a Law Enforcement Working Group that was formed to collaborate on common operational needs. All agencies represented on the working group ranked their need to tag, track, and locate a witting or unwitting target as their highest priority. Specifically, they were looking for technologies more robust than Global Positioning Satellite (GPS), could communicate back to the owner, and worked where normal cell phone communications did not work or were unreliable. SRNL brought together multiple technologies in a demonstration that was held in in various Alaska venues, including metropolitan, wilderness, and at-sea that met the working group's requirements. Using prototypical technologies from Boeing, On Ramp, and Fortress, SRNL was able to demonstrate the ability to track personnel and material in all scenarios including indoors, in heavily wooden areas, canyons, and in parking garages. In all cases GPS signals were too weak to measure. Bi-directional communication was achieved in areas that Wi-Fi, cell towers, or traditional radios would not perform. The results of the exercise will be presented. These technologies are considered ideal for tracking high value material such has nuclear material with a platform that allows seamless tracking anywhere in the …
Date: July 8, 2012
Creator: Cordaro, J.; Coleman, T. & Shull, D.
Object Type: Article
System: The UNT Digital Library
RADIOACTIVE HIGH LEVEL WASTE TANK PITTING PREDICTIONS: AN INVESTIGATION INTO CRITICAL SOLUTION CONCENTRATIONS (open access)

RADIOACTIVE HIGH LEVEL WASTE TANK PITTING PREDICTIONS: AN INVESTIGATION INTO CRITICAL SOLUTION CONCENTRATIONS

A series of cyclic potentiodynamic polarization tests was performed on samples of ASTM A537 carbon steel in support of a probability-based approach to evaluate the effect of chloride and sulfate on corrosion the steel�s susceptibility to pitting corrosion. Testing solutions were chosen to systemically evaluate the influence of the secondary aggressive species, chloride, and sulfate, in the nitrate based, high-level wastes. The results suggest that evaluating the combined effect of all aggressive species, nitrate, chloride, and sulfate, provides a consistent response for determining corrosion susceptibility. The results of this work emphasize the importance for not only nitrate concentration limits, but also chloride and sulfate concentration limits.
Date: November 8, 2012
Creator: Hoffman, E.
Object Type: Article
System: The UNT Digital Library
Thermal characteristics of air flow cooling in the lithium ion batteries experimental chamber (open access)

Thermal characteristics of air flow cooling in the lithium ion batteries experimental chamber

A battery pack prototype has been designed and built to evaluate various air cooling concepts for the thermal management of Li-ion batteries. The heat generation from the Li-Ion batteries was simulated with electrical heat generation devices with the same dimensions as the Li-Ion battery (200 mm x 150 mm x 12 mm). Each battery simulator generates up to 15W of heat. There are 20 temperature probes placed uniformly on the surface of the battery simulator, which can measure temperatures in the range from -40 C to +120 C. The prototype for the pack has up to 100 battery simulators and temperature probes are recorder using a PC based DAQ system. We can measure the average surface temperature of the simulator, temperature distribution on each surface and temperature distributions in the pack. The pack which holds the battery simulators is built as a crate, with adjustable gap (varies from 2mm to 5mm) between the simulators for air flow channel studies. The total system flow rate and the inlet flow temperature are controlled during the test. The cooling channel with various heat transfer enhancing devices can be installed between the simulators to investigate the cooling performance. The prototype was designed to configure …
Date: July 8, 2012
Creator: A., Lukhanin; U., Rohatgi; Belyaev, A.; Fedorchenko, D.; Khazhmuradov, M.; Lukhanin, O et al.
Object Type: Article
System: The UNT Digital Library
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
Object Type: Article
System: The UNT Digital Library
Development of the bus joint for the ITER Central Solenoid (open access)

Development of the bus joint for the ITER Central Solenoid

None
Date: August 8, 2012
Creator: Martovetsky, N. N.; Irick, D. K. & Kenney, S. J.
Object Type: Article
System: The UNT Digital Library
Finding Motifs in Wind Generation Time Series Data (open access)

Finding Motifs in Wind Generation Time Series Data

None
Date: August 8, 2012
Creator: Kamath, C & Fan, Y J
Object Type: Article
System: The UNT Digital Library
Channel Modeling and Time Delay Estimation for Clock Synchronization Among Seaweb Nodes (open access)

Channel Modeling and Time Delay Estimation for Clock Synchronization Among Seaweb Nodes

From simulations, tracking of the impulse response is feasible. Potential to benefit other functions such as ranging between two nodes. Potential to combine the features of different protocols to create a new and more realistic clock-synchronization protocol.
Date: July 8, 2012
Creator: Gagnon, Pascal; Rice, Joseph A. & Clark, Grace A.
Object Type: Article
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
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
Biorefinery and Carbon Cycling Research Project (open access)

Biorefinery and Carbon Cycling Research Project

In this project we focused on several aspects of technology development that advances the formation of an integrated biorefinery. These focus areas include: [ 1] pretreatment of biomass to enhance quality of products from thermochemical conversion; [2] characterization of and development of coproduct uses; [3] advancement in fermentation of lignocellulosics and particularly C5 and C6 sugars simultaneously, and [ 4] development of algal biomass as a potential substrate for the biorefinery. These advancements are intended to provide a diverse set of product choices within the biorefinery, thus improving the cost effectiveness of the system. Technical effectiveness was demonstrated in the thermochemical product quality in the form of lower tar production, simultaneous of use of multiple sugars in fermentation, use ofbiochar in environmental (ammonia adsorption) and agricultural applications, and production of algal biomass in wastewaters. Economic feasibility of algal biomass production systems seems attractive, relative to the other options. However, further optimization in all paths, and testing/demonstration at larger scales are required to fully understand the economic viabilities. The coproducts provide a clear picture that multiple streams of value can be generated within an integrated biorefinery, and these include fuels and products.
Date: June 8, 2012
Creator: Das, K. C., Adams; Thomas, T; Eiteman, Mark A; Kastner, James R; Mani, Sudhagar & Adolphson, Ryan
Object Type: Report
System: The UNT Digital Library
Computer experiments on the onset of turbulence (open access)

Computer experiments on the onset of turbulence

None
Date: August 8, 2012
Creator: Weisgraber, T H & Alder, B J
Object Type: Article
System: The UNT Digital Library
Cloud Condensation Nuclei Profile Value-Added Product (open access)

Cloud Condensation Nuclei Profile Value-Added Product

The cloud condensation nuclei (CCN) concentration at cloud base is the most relevant measure of the aerosol that influences droplet formation in clouds. Since the CCN concentration depends on supersaturation, a more general measure of the CCN concentration is the CCN spectrum (values at multiple supersaturations). The CCN spectrum is now measured at the surface at several fixed ARM sites and by the ARM Mobile Facility (AMF), but is not measured at the cloud base. Rather than rely on expensive aircraft measurements for all studies of aerosol effects on clouds, a way to project CCN measurements at the surface to cloud base is needed. Remote sensing of aerosol extinction provides information about the vertical profile of the aerosol, but cannot be directly related to the CCN concentration because the aerosol extinction is strongly influenced by humidification, particularly near cloud base. Ghan and Collins (2004) and Ghan et al. (2006) propose a method to remove the influence of humidification from the extinction profiles and tie the “dry extinction” retrieval to the surface CCN concentration, thus estimating the CCN profile. This methodology has been implemented as the CCN Profile (CCNPROF) value-added product (VAP).
Date: October 8, 2012
Creator: McFarlane, S; Sivaraman, C & Ghan, S
Object Type: Report
System: The UNT Digital Library
Improved capture gamma-ray libraries for nuclear applications (open access)

Improved capture gamma-ray libraries for nuclear applications

None
Date: October 8, 2012
Creator: Hurst, A. M.; Sleaford, B. W.; Firestone, R. B.; Summers, N. C.; Revay, Z.; Szentmiklosi, L. et al.
Object Type: Report
System: The UNT Digital Library
Nano-mechanics of Tunable Adhesion using Non Covalent Forces (open access)

Nano-mechanics of Tunable Adhesion using Non Covalent Forces

The objective of this program was to examine, via experiment and atomistic and continuum analysis, coordinated noncovalent bonding over a range of length scales with a view to obtaining modulated, patterned and reversible bonding at the molecular level. The first step in this project was to develop processes for depositing self-assembled monolayers (SAMs) bearing carboxylic acid and amine moieties on Si (111) surfaces and probe tips of an interfacial force microscope (IFM). This allowed the adhesive portion of the interactions between functionalized surfaces to be fully captured in the force-displacement response (force profiles) that are measured by the IFM. The interactionswere extracted in the form of traction-separation laws using combined molecular and continuum stress analyses. In this approach, the results of molecular dynamics analyses of SAMs subjected to simple stress states are used to inform continuum models of their stress-strain behavior. Continuum analyses of the IFM experiment were then conducted, which incorporate the stress-strain behavior of the SAMs and traction-separation relations that represent the interactions between the tip and functionalized Si surface. Agreement between predicted and measured force profiles was taken to imply that the traction-separation relations have been properly extracted. Scale up to larger contact areas was considered by …
Date: September 8, 2012
Creator: Liechti, Kenneth
Object Type: Report
System: The UNT Digital Library
Dosimetric Quantities and Neutron Spectra Outside the Shielding of Electron Accelerators (open access)

Dosimetric Quantities and Neutron Spectra Outside the Shielding of Electron Accelerators

None
Date: October 8, 2012
Creator: Fasso, Alberto; Lab, /SLAC /Jefferson; Liu, James C.; Rokni, Sayed H & /SLAC
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
THORs Power Method for Hydrokinetic Devices - Final Report (open access)

THORs Power Method for Hydrokinetic Devices - Final Report

Ocean current energy represents a vast untapped source of renewable energy that exists on the outer continental shelf areas of the 5 major continents. Ocean currents are unidirectional in nature and are perpetuated by thermal and salinity sea gradients, as well as coriolis forces imparted from the earth's rotation. This report details THORs Power Method, a breakthrough power control method that can provide dramatic increases to the capacity factor over and above existing marine hydrokinetic (MHK) devices employed in the extraction of energy from ocean currents. THORs Power Method represents a constant speed, variable depth operational method that continually locates the ocean current turbine at a depth at which the rated power of the generator is routinely achieved. Variable depth operation is achieved by using various vertical force effectors, including ballast tanks for variable weight, a hydrodynamic wing for variable lift or down force and drag flaps for variable vehicle drag forces.
Date: August 8, 2012
Creator: Hunt, J. Turner & Rumker, Joel
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
"Fine grain Nb tube for SRF cavities" (open access)

"Fine grain Nb tube for SRF cavities"

Superconducting radio frequency (SRF) cavities used in charged particle linear accelerators, are currently fabricated by deep drawing niobium sheets and welding the drawn dishes together. The Nb sheet has a non-uniform microstructure, which leads to unpredictable cavity shape and surface roughness, and inconsistent "spring-back" during forming. In addition, weld zones cause hot spots during cavity operation. These factors limit linear accelerator performance and increase cavity manufacturing cost. Equal channel angular extrusion (ECAE) can be used to refine and homogenize the microstructure of Nb tube for subsequent hydroforming into SRF cavities. Careful selection of deformation and heat treatment conditions during the processing steps can give a uniform and consistent microstructure in the tube, leading to improved deformability and lower manufacturing costs. Favorable microstructures were achieved in short test samples of RRR Nb tube, which may be particularly suitable for hydroforming into SRF cavity strings. The approach demonstrated could be applicable to microstructure engineering of other tube materials including tantalum, titanium, and zirconium.
Date: July 8, 2012
Creator: Barber, Robert E.
Object Type: Report
System: The UNT Digital Library
Neptunium_Oxide_Precipitation_Kinetics_AJohnsen (open access)

Neptunium_Oxide_Precipitation_Kinetics_AJohnsen

We evaluate the proposed NpO{sub 2}{sup +}(aq)-NpO{sub 2}(cr) reduction-precipitation system at elevated temperatures to obtain primary information on the effects of temperature, ionic strength, O{sub 2} and CO{sub 2}. Experiments conducted on unfiltered solutions at 10{sup -4} M NpO{sub 2}{sup +}(aq), neutral pH, and 200 C indicated that solution colloids strongly affect precipitation kinetics. Subsequent experiments on filtered solutions at 200, 212, and 225 C showed consistent and distinctive temperature-dependent behavior at reaction times {le} 800 hours. At longer times, the 200 C experiments showed unexpected dissolution of neptunium solids, but experiments at 212 C and 225 C demonstrated quasi steady-state neptunium concentrations of 3 x 10{sup -6} M and 6 x 10{sup -6} M, respectively. Solids from a representative experiment analyzed by X-ray diffraction were consistent with NpO{sub 2}(cr). A 200 C experiment with a NaCl concentration of 0.05 M showed a dramatic increase in the rate of neptunium loss. A 200 C experiment in an argon atmosphere resulted in nearly complete loss of aqueous neptunium. Previously proposed NpO{sub 2}{sup +}(aq)-NpO{sub 2}(cr) reduction-precipitation mechanisms in the literature specified a 1:1 ratio of neptunium loss and H{sup +} production in solution over time. However, all experiments demonstrated ratios of approximately …
Date: June 8, 2012
Creator: Johnsen, A. M.; Roberts, K. E. & Prussin, S. G.
Object Type: Report
System: The UNT Digital Library
Potential Emissions of Tritium in Air from Wells on the Nevada National Security Site (open access)

Potential Emissions of Tritium in Air from Wells on the Nevada National Security Site

This slide-show discusses the Nevada National Security Site (NNSS) and tritium in the groundwater. It describes the wells and boreholes and potential airflow from these sources. Monitoring of selected wells is discussed and preliminary results are presented.
Date: October 8, 2012
Creator: Warren, R.
Object Type: Article
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
ANALYSIS OF HARRELL MONOSODIUM TITANATE LOT #s 46000606120, 46000722120, AND 46000808120 (open access)

ANALYSIS OF HARRELL MONOSODIUM TITANATE LOT #s 46000606120, 46000722120, AND 46000808120

Monosodium titanate (MST) for use in the Actinide Removal Process (ARP) must be qualified and verified in advance. A single qualification sample for each batch of material is sent to SRNL for analysis, as well as a statistical sampling of verification samples. The Harrell Industries Lot #s 46000706120, 46000722120, and 460008081120 qualification and verification samples met each of the selected specification requirements that were tested with the exception of a few pails being marginally below the lower weight percent solids limit. These deviations from the specifications are viewed as negligible since the corresponding density of the slurries indicates no appreciable shortage of MST solids. Therefore, SRNL recommends acceptance and use of these pails.
Date: October 8, 2012
Creator: Taylor-Pashow, K.
Object Type: Report
System: The UNT Digital Library