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Intraocular Pressure Changes: An Important Determinant of the Biocompatibility of Intravitreous Implants (open access)

Intraocular Pressure Changes: An Important Determinant of the Biocompatibility of Intravitreous Implants

Article discussing intraocular pressure changes and an important determinant of the biocompatibility of intravitreous implants.
Date: December 14, 2011
Creator: Zou, Ling; Nair, Ashwin; Weng, Hong; Tsai, Yi-Ting; Hu, Zhibing & Tang, Liping
System: The UNT Digital Library
Newton flow of the Riemann zeta function: separatrices control the appearance of zeros (open access)

Newton flow of the Riemann zeta function: separatrices control the appearance of zeros

This article applies the continuous Newton method to the Riemann zeta function and discusses the emerging patterns emphasizing especially the structuring of the non-trivial zeros by the separatrices.
Date: October 14, 2014
Creator: Neuberger, J. W.; Feiler, C.; Llopis, A.; Maier, H. & Schleich, W. P.
System: The UNT Digital Library
Gamma-ray Mirrors for Direct Measurement of Spent Nuclear Fuel (open access)

Gamma-ray Mirrors for Direct Measurement of Spent Nuclear Fuel

None
Date: June 14, 2013
Creator: Pivovaroff, M. J.; Ziock, K. P.; Fernandez-Perea, M.; Harrison, M. J. & Soufli, R.
System: The UNT Digital Library
Efficient multiband and broadband cross polarization converters based on slotted Lshaped nanoantennas (open access)

Efficient multiband and broadband cross polarization converters based on slotted Lshaped nanoantennas

This article presents highly efficient reflective cross polarization converters based on metamaterials operating in the infrared regime.
Date: November 14, 2014
Creator: Ding, Jun; Arigong, Bayaner; Ren, Han; Zhou, Mi; Shao, Jin; Lin, Yuankun et al.
System: The UNT Digital Library
Overlapping geographic clusters of food security and health: Where do social determinants and health outcomes converge in the U.S? (open access)

Overlapping geographic clusters of food security and health: Where do social determinants and health outcomes converge in the U.S?

This article identifies geographic clusters of food insecurity and health across U.S. counties to identify potential shared mechanisms for geographic disparities in health and food insecurity.
Date: June 14, 2018
Creator: Leonard, Tammy; Hughes, Amy; Donegan, Connor; Santillan, Alejandro & Pruitt, Sandi L.
System: The UNT Digital Library
Large Synoptic Survey Telescope: From Science Drivers to Reference Design (open access)

Large Synoptic Survey Telescope: From Science Drivers to Reference Design

In the history of astronomy, major advances in our understanding of the Universe have come from dramatic improvements in our ability to accurately measure astronomical quantities. Aided by rapid progress in information technology, current sky surveys are changing the way we view and study the Universe. Next-generation surveys will maintain this revolutionary progress. We focus here on the most ambitious survey currently planned in the visible band, the Large Synoptic Survey Telescope (LSST). LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: constraining dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. It will be a large, wide-field ground-based system designed to obtain multiple images covering the sky that is visible from Cerro Pachon in Northern Chile. The current baseline design, with an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg{sup 2} field of view, and a 3,200 Megapixel camera, will allow about 10,000 square degrees of sky to be covered using pairs of 15-second exposures in two photometric bands every three nights on average. The system is designed to yield high image …
Date: October 14, 2011
Creator: Ivezic, Z.; Axelrod, T.; Brandt, W. N.; Burke, D. L.; Claver, C. F.; Connolly, A. et al.
System: The UNT Digital Library
A model for improving microbial biofuel production using a synthetic feedback loop (open access)

A model for improving microbial biofuel production using a synthetic feedback loop

Cells use feedback to implement a diverse range of regulatory functions. Building synthetic feedback control systems may yield insight into the roles that feedback can play in regulation since it can be introduced independently of native regulation, and alternative control architectures can be compared. We propose a model for microbial biofuel production where a synthetic control system is used to increase cell viability and biofuel yields. Although microbes can be engineered to produce biofuels, the fuels are often toxic to cell growth, creating a negative feedback loop that limits biofuel production. These toxic effects may be mitigated by expressing efflux pumps that export biofuel from the cell. We developed a model for cell growth and biofuel production and used it to compare several genetic control strategies for their ability to improve biofuel yields. We show that controlling efflux pump expression directly with a biofuel-responsive promoter is a straight forward way of improving biofuel production. In addition, a feed forward loop controller is shown to be versatile at dealing with uncertainty in biofuel production rates.
Date: July 14, 2011
Creator: Dunlop, Mary; Keasling, Jay & Mukhopadhyay, Aindrila
System: The UNT Digital Library
THE POTENTIAL OF NANOPARTICLE ENHANCED IONIC LIQUIDS (NEILS) AS ADVANCED HEAT TRANSFER FLUIDS (open access)

THE POTENTIAL OF NANOPARTICLE ENHANCED IONIC LIQUIDS (NEILS) AS ADVANCED HEAT TRANSFER FLUIDS

Interest in capturing the energy of the sun is rising as demands for renewable energy sources increase. One area of developing research is the use of concentrating solar power (CSP), where the solar energy is concentrated by using mirrors to direct the sunlight towards a collector filled with a heat transfer fluid (HTF). The HTF transfers the collected energy into pressurized steam, which is used to generate energy. The greater the energy collected by the HTF, the more efficent the electrical energy production is, thus the overall efficiency is controlled by the thermal fluid. Commercial HTFs such as Therminol{reg_sign} (VP-1), which is a blend of biphenyl and diphenyl oxide, have a significant vapor pressure, especially at elevated temperatures. In order for these volatile compounds to be used in CSP systems, the system either has to be engineered to prevent the phase change (i.e., volatilization and condensation) through pressurization of the system, or operate across the phase change. Over thirty years ago, a class of low-melting organic compounds were developed with negligible vapor pressure. These compounds are referred to as ionic liquids (ILs), which are organic-based compounds with discrete charges that cause a significant decrease in their vapor pressure. As a …
Date: September 14, 2011
Creator: Fox, E.; Bridges, N. & Visser, A.
System: The UNT Digital Library
Enhanced Superconducting Gaps in Trilayer High-Temperature Bi (2) Sr (2) Ca (2) Cu (3) O (10+delta) Cuprate Superconductor (open access)

Enhanced Superconducting Gaps in Trilayer High-Temperature Bi (2) Sr (2) Ca (2) Cu (3) O (10+delta) Cuprate Superconductor

None
Date: November 14, 2012
Creator: Ideta, S.; Takashima, K.; Hashimoto, M.; Yoshida, T.; Fujimori, A.; Anzai, H. et al.
System: The UNT Digital Library
NARAC Modeling During the Response to the Fukushima Dai-ichi Nuclear Power Plant Emergency (open access)

NARAC Modeling During the Response to the Fukushima Dai-ichi Nuclear Power Plant Emergency

This paper summarizes the activities of the National Atmospheric Release Advisory Center (NARAC) during the Fukushima Dai-ichi nuclear power plant crisis. NARAC provided a wide range of products and analyses as part of its support including: (1) Daily Japanese weather forecasts and hypothetical release (generic source term) dispersion predictions to provide situational awareness and inform planning for U.S. measurement data collection and field operations; (2) Estimates of potential dose in Japan for hypothetical scenarios developed by the Nuclear Regulatory Commission (NRC) to inform federal government considerations of possible actions that might be needed to protect U.S. citizens in Japan; (3) Estimates of possible plume arrival times and dose for U.S. locations; and (4) Plume model refinement and source estimation based on meteorological analyses and available field data. The Department of Energy/National Nuclear Security Administration (DOE/NNSA) deployed personnel to Japan and stood up 'home team' assets across the DOE complex to aid in assessing the consequences of the releases from the Fukushima Dai-ichi Nuclear Power Plant. The DOE Nuclear Incident Team (NIT) coordinated response activities, while DOE personnel provided predictive modeling, air and ground monitoring, sample collection, laboratory analysis, and data assessment and interpretation. DOE deployed the Aerial Measuring System (AMS), …
Date: February 14, 2012
Creator: Sugiyama, G.; Nasstrom, J. S.; Probanz, B.; Foster, K. T.; Simpson, M.; Vogt, P. et al.
System: The UNT Digital Library
Studies of non-proportionality in alkali halide and strontium iodide scintillators using SLYNCI (open access)

Studies of non-proportionality in alkali halide and strontium iodide scintillators using SLYNCI

Recently a collaboration of LLNL and LBNL has constructed a second generation Compton coincidence instrument to study the non-proportionality of scintillators. This device, known as SLYNCI (Scintillator Light-Yield Non-proportionality Characterization Instrument), has can completely characterize a sample with less than 24 hours of running time. Thus, SLYNCI enables a number of systematic studies of scintillators since many samples can be processed in a reasonable length of time. These studies include differences in nonproportionality between different types of scintillators, different members of the same family of scintillators, and impact of different doping levels. The results of such recent studies are presented here, including a study of various alkali halides, and the impact of europium doping level in strontium iodide. Directions of future work area also discussed.
Date: October 14, 2010
Creator: Ahle, Larry; Bizarri, Gregory; Boatner, Lynn; Cherepy, Nerine J.; Choong, Woon-Seng; Moses, William W. et al.
System: The UNT Digital Library
Mechanical Design of the HER Synchrotron Light Monitor Primary Mirror (open access)

Mechanical Design of the HER Synchrotron Light Monitor Primary Mirror

This paper describes the mechanical design of the primary mirror that images the visible portion of the synchrotron radiation (SR) extracted from the High Energy Ring (HER) of the PEP-II B-Factory. During off-axis operation, the water-cooled GlidCop mirror is subjected to a heat flux in excess of 2000 W/cm2. When on-axis imaging occurs, the heat flux due to scattered SR, resistive wall losses and Higher-Order-Mode (HOM) heating is estimated at 1 W/cm2. The imaging surface is plated with Electroless Nickel to improve its optical characteristics. The design requirements for the primary mirror are listed and discussed. Calculated mechanical distortions and stresses experienced by the mirror during on-axis and off-axis operation will be presented.
Date: September 14, 2011
Creator: Daly, Edward F.; Fisher, Alan S.; Kurita, Nadine R. & Langton, J.
System: The UNT Digital Library
Systematic Uncertainties in NLO PS Matching (open access)

Systematic Uncertainties in NLO PS Matching

None
Date: December 14, 2012
Creator: Schonherr, Marek; Hoeche, Stefan; Krauss, Frank & Siegert, Frank
System: The UNT Digital Library
THERMAL ANALYSIS OF A 9975 PACKAGE IN A FACILITY FIRE ACCIDENT (open access)

THERMAL ANALYSIS OF A 9975 PACKAGE IN A FACILITY FIRE ACCIDENT

Surplus plutonium bearing materials in the U.S. Department of Energy (DOE) complex are stored in the 3013 containers that are designed to meet the requirements of the DOE standard DOE-STD-3013. The 3013 containers are in turn packaged inside 9975 packages that are designed to meet the NRC 10 CFR Part 71 regulatory requirements for transporting the Type B fissile materials across the DOE complex. The design requirements for the hypothetical accident conditions (HAC) involving a fire are given in 10 CFR 71.73. The 9975 packages are stored at the DOE Savannah River Site in the K-Area Material Storage (KAMS) facility for long term of up to 50 years. The design requirements for safe storage in KAMS facility containing multiple sources of combustible materials are far more challenging than the HAC requirements in 10 CFR 71.73. While the 10 CFR 71.73 postulates an HAC fire of 1475 F and 30 minutes duration, the facility fire calls for a fire of 1500 F and 86 duration. This paper describes a methodology and the analysis results that meet the design limits of the 9975 component and demonstrate the robustness of the 9975 package.
Date: February 14, 2011
Creator: Gupta, N.
System: The UNT Digital Library
CONTAINMENT VESSEL TEMPERATURE FOR PU-238 HEAT SOURCE CONTAINER UNDER AMBIENT, FREE CONVECTION AND LOW EMISSIVITY COOLING CONDITIONS (open access)

CONTAINMENT VESSEL TEMPERATURE FOR PU-238 HEAT SOURCE CONTAINER UNDER AMBIENT, FREE CONVECTION AND LOW EMISSIVITY COOLING CONDITIONS

The EP-61 primary containment vessel of the 5320 shipping package has been used for storage and transportation of Pu-238 plutonium oxide heat source material. For storage, the material in its convenience canister called EP-60 is placed in the EP-61 and sealed by two threaded caps with elastomer O-ring seals. When the package is shipped, the outer cap is seal welded to the body. While stored, the EP-61s are placed in a cooling water bath. In preparation for welding, several containers are removed from storage and staged to the welding booth. The significant heat generation of the contents, and resulting rapid rise in component temperature necessitates special handling practices. The test described here was performed to determine the temperature rise with time and peak temperature attained for an EP-61 with 203 watts of internal heat generation, upon its removal from the cooling water bath.
Date: February 14, 2011
Creator: Gupta, N. & Smith, A.
System: The UNT Digital Library
Structural and electrochemical Investigation of Li(Ni0.4Co0.2-yAlyMn0.4)O2 Cathode Material (open access)

Structural and electrochemical Investigation of Li(Ni0.4Co0.2-yAlyMn0.4)O2 Cathode Material

Li(Ni{sub 0.4}Co{sub 0.15}Al{sub 0.05}Mn{sub 0.4})O{sub 2} was investigated to understand the effect of replacement of the cobalt by aluminum on the structural and electrochemical properties. In situ X-ray absorption spectroscopy (XAS) was performed, utilizing a novel in situ electrochemical cell, specifically designed for long-term X-ray experiments. The cell was cycled at a moderate rate through a typical Li-ion battery operating voltage range. (1.0-4.7 V) XAS measurements were performed at different states of charge (SOC) during cycling, at the Ni, Co, and the Mn edges, revealing details about the response of the cathode to Li insertion and extraction processes. The extended X-ray absorption fine structure (EXAFS) region of the spectra revealed the changes of bond distance and coordination number of Ni, Co, and Mn absorbers as a function of the SOC of the material. The oxidation states of the transition metals in the system are Ni{sup 2+}, Co{sup 3+}, and Mn{sup 4+} in the as-made material (fully discharged), while during charging the Ni{sup 2+} is oxidized to Ni{sup 4+} through an intermediate stage of Ni{sup 3+}, Co{sup 3+} is oxidized toward Co{sup 4+}, and Mn was found to be electrochemically inactive and remained as Mn{sup 4+}. The EXAFS results during cycling …
Date: June 14, 2010
Creator: Rumble, C.; Conry, T.E.; Doeff, Marca; Cairns, Elton J.; Penner-Hahn, James E. & Deb, Aniruddha
System: The UNT Digital Library
Do Heat Pump Clothes Dryers Make Sense for the U.S. Market (open access)

Do Heat Pump Clothes Dryers Make Sense for the U.S. Market

Heat pump clothes dryers (HPCDs) can be as much as 50percent more energy-efficient than conventional electric resistance clothes dryers, and therefore have the potential to save substantial amounts of electricity. While not currently available in the U.S., there are manufacturers in Europe and Japan that produce units for those markets. Drawing on analysis conducted for the U.S. Department of Energy's (DOE) current rulemaking on amended standards for clothes dryers, this paper evaluates the cost-effectiveness of HPCDs in American homes, as well as the national impact analysis for different market share scenarios. In order to get an accurate measurement of real energy savings potential, the paper offers a new energy use calculation methodology that takes into account the most current data on clothes washer cycles, clothes dryer usage frequency, remaining moisture content, and load weight per cycle, which is very different from current test procedure values. Using the above methodology along with product cost estimates developed by DOE, the paper presents the results of a life-cycle cost analysis of the adoption of HPCDs in a representative sample of American homes. The results show that HPCDs have positive economic benefits only for households with high clothes dryer usage or for households with …
Date: May 14, 2010
Creator: Meyers, Steve; Franco, Victor; Lekov, Alex; Thompson, Lisa & Sturges, Andy
System: The UNT Digital Library
Electrically detected magnetic resonance in a W-band microwave cavity (open access)

Electrically detected magnetic resonance in a W-band microwave cavity

We describe a low-temperature sample probe for the electrical detection of magnetic resonance in a resonant W-band (94 GHz) microwave cavity. The advantages of this approach are demonstrated by experiments on silicon field-effect transistors. A comparison with conventional low-frequency measurements at X-band (9.7 GHz) on the same devices reveals an up to 100-fold enhancement of the signal intensity. In addition, resonance lines that are unresolved at X-band are clearly separated in the W-band measurements. Electrically detected magnetic resonance at high magnetic fields and high microwave frequencies is therefore a very sensitive technique for studying electron spins with an enhanced spectral resolution and sensitivity.
Date: January 14, 2011
Creator: Lang, V.; Lo, C. C.; George, R. E.; Lyon, S. A.; Bokor, J.; Schenkel, T. et al.
System: The UNT Digital Library
The DEEP2 Galaxy Redshift Survey: The Voronoi-Delaunay Method Catalog of Galaxy Groups (open access)

The DEEP2 Galaxy Redshift Survey: The Voronoi-Delaunay Method Catalog of Galaxy Groups

We use the first 25% of the DEEP2 Galaxy Redshift Survey spectroscopic data to identify groups and clusters of galaxies in redshift space. The data set contains 8370 galaxies with confirmed redshifts in the range 0.7 {<=} z {<=} 1.4, over one square degree on the sky. Groups are identified using an algorithm (the Voronoi-Delaunay Method) that has been shown to accurately reproduce the statistics of groups in simulated DEEP2-like samples. We optimize this algorithm for the DEEP2 survey by applying it to realistic mock galaxy catalogs and assessing the results using a stringent set of criteria for measuring group-finding success, which we develop and describe in detail here. We find in particular that the group-finder can successfully identify {approx}78% of real groups and that {approx}79% of the galaxies that are true members of groups can be identified as such. Conversely, we estimate that {approx}55% of the groups we find can be definitively identified with real groups and that {approx}46% of the galaxies we place into groups are interloper field galaxies. Most importantly, we find that it is possible to measure the distribution of groups in redshift and velocity dispersion, n({sigma}, z), to an accuracy limited by cosmic variance, for …
Date: February 14, 2012
Creator: Gerke, Brian F.; Newman, Jeffrey A.; Davis, Marc; Marinoni, Christian; Yan, Renbin; Coil, Alison L. et al.
System: The UNT Digital Library
Branching Fraction Measurements of the Color-Suppressed Decays B0bar to D(*)0 pi0, D(*)0 eta, D(*)0 omega, and D(*)0 eta_prime and Measurement of the Polarization in the Decay B0bar to D*0 omega (open access)

Branching Fraction Measurements of the Color-Suppressed Decays B0bar to D(*)0 pi0, D(*)0 eta, D(*)0 omega, and D(*)0 eta_prime and Measurement of the Polarization in the Decay B0bar to D*0 omega

We report updated branching fraction measurements of the color-suppressed decays {bar B}{sup 0} {yields} D{sup 0}{pi}{sup 0}, D*{sup 0}{pi}{sup 0}, D{sup 0}{eta}, D*{sup 0}{eta}, D{sup 0}{omega}, D*{sup 0}{omega}, D{sup 0}{eta}', and D*{sup 0}{eta}'. We measure the branching fractions (x10{sup -4}): {Beta}({bar B}{sup 0} {yields} D{sup 0}{pi}{sup 0}) = 2.69 {+-} 0.09 {+-} 0.13, {Beta}({bar B}{sup 0} {yields} D*{sup 0}{pi}{sup 0}) = 3.05 {+-} 0.14 {+-} 0.28, {Beta}({bar B}{sup 0} {yields} D{sup 0}{eta}) = 2.53 {+-} 0.09 {+-} 0.11, {Beta}({bar B}{sup 0} {yields} D*{sup 0}{eta}) = 2.69 {+-} 0.14 {+-} 0.23, {Beta}({bar B}{sup 0} {yields} D{sup 0}{omega}) = 2.57 {+-} 0.11 {+-} 0.14, {Beta}({bar B}{sup 0} {yields} D*{sup 0}{omega}) = 4.55 {+-} 0.24 {+-} 0.39, {Beta}({bar B}{sup 0} {yields} D{sup 0}{eta}') = 1.48 {+-} 0.13 {+-} 0.07, and {Beta}({bar B}{sup 0} {yields} D*{sup 0}{eta}') = 1.49 {+-} 0.22 {+-} 0.15. We also present the first measurement of the longitudinal polarization fraction of the decay channel D*{sup 0}{omega}, f{sub L} = (66.5 {+-} 4.7 {+-} 1.5)%. In the above, the first uncertainty is statistical and the second is systematic. The results are based on a sample of (454 {+-} 5) x 10{sup 6} B{bar B} pairs collected at the {Upsilon}(4S) resonance, with …
Date: February 14, 2012
Creator: Lees, J. P.; Poireau, V.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M. et al.
System: The UNT Digital Library
Issues in Equation of State data generation for Hot Dense MatterA Note on Generalized Radial Mesh Generation for Plasma Electronic Structure (open access)

Issues in Equation of State data generation for Hot Dense MatterA Note on Generalized Radial Mesh Generation for Plasma Electronic Structure

Precise electronic structure calculations of ions in plasmas benefit from optimized numerical radial meshes. A new closed form expression for obtaining non-linear parameters for the efficient generation of analytic log-linear radial meshes is presented. In conjunction with the (very simple) algorithm for the rapid high precision evaluation of Lambert's W-function, the above identity allows the precise construction of generalized log-linear radial meshes adapted to various constraints.
Date: February 14, 2011
Creator: Wilson, B G & Sonnad, V
System: The UNT Digital Library
The Network Completion Problem: Inferring Missing Nodes and Edges in Networks (open access)

The Network Completion Problem: Inferring Missing Nodes and Edges in Networks

Network structures, such as social networks, web graphs and networks from systems biology, play important roles in many areas of science and our everyday lives. In order to study the networks one needs to first collect reliable large scale network data. While the social and information networks have become ubiquitous, the challenge of collecting complete network data still persists. Many times the collected network data is incomplete with nodes and edges missing. Commonly, only a part of the network can be observed and we would like to infer the unobserved part of the network. We address this issue by studying the Network Completion Problem: Given a network with missing nodes and edges, can we complete the missing part? We cast the problem in the Expectation Maximization (EM) framework where we use the observed part of the network to fit a model of network structure, and then we estimate the missing part of the network using the model, re-estimate the parameters and so on. We combine the EM with the Kronecker graphs model and design a scalable Metropolized Gibbs sampling approach that allows for the estimation of the model parameters as well as the inference about missing nodes and edges of …
Date: November 14, 2011
Creator: Kim, M & Leskovec, J
System: The UNT Digital Library
Fireside Corrosion (open access)

Fireside Corrosion

Oxy-fuel fireside research goals are: (1) determine the effect of oxyfuel combustion on fireside corrosion - flue gas recycle choice, staged combustion ramifications; and (2) develop methods to use chromia solubility in ash as an ash corrosivity measurement - synthetic ashes at first, then boiler and burner rig ashes.
Date: July 14, 2011
Creator: Holcomb, Gordon
System: The UNT Digital Library
Life extension program for the modular caustic side solvent extraction unit at Savannah River Site (open access)

Life extension program for the modular caustic side solvent extraction unit at Savannah River Site

Caustic Side Solvent Extraction (CSSX) is currently used at the U.S. Department of Energy (DOE) Savannah River Site (SRS) for removal of cesium from the high-level salt-wastes stored in underground tanks. At SRS, the CSSX process is deployed in the Modular CSSX Unit (MCU). The CSSX technology utilizes a multi-component organic solvent and annular centrifugal contactors to extract cesium from alkaline salt waste. Coalescers and decanters process the Decontaminated Salt Solution (DSS) and Strip Effluent (SE) streams to allow recovery and reuse of the organic solvent and to limit the quantity of solvent transferred to the downstream facilities. MCU is operated in series with the Actinide Removal Process (ARP) which removes strontium and actinides from salt waste utilizing monosodium titanate. ARP and MCU were developed and implemented as interim salt processing until future processing technology, the CSSX-based Salt Waste Processing Facility (SWPF), is operational. SWPF is slated to come on-line in October 2014. The three year design life of the ARP/MCU process, however, was reached in April 2011. Nevertheless, most of the individual process components are capable of operating longer. An evaluation determined ARP/MCU can operate until 2015 before major equipment failure is expected. The three year design life of …
Date: November 14, 2012
Creator: Samadi-Dezfouli, Azadeh
System: The UNT Digital Library