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137Cs and 210Po in Pacific Walrus and Bearded Seal from St. Lawrence Island, Alaska (open access)

137Cs and 210Po in Pacific Walrus and Bearded Seal from St. Lawrence Island, Alaska

The activity concentration of Cesium-137 ({sup 137}Cs) and naturally-occurring Polonium-210 ({sup 210}Po) were measured in the muscle tissue, kidney and liver of Pacific walrus (Odobenus rosmarus divergens) and bearded seal (Erignathus barbatus) collected by native hunters from the Bering Sea. The mean {sup 137}Cs concentrations in muscle, liver and kidney of Pacific walrus were 0.07, 0.09 and 0.07 Bq kg{sup -1} (N= 5, wet weight), respectively, and 0.17, 0.10, and 0.17 Bq kg{sup -1} (N=2, wet weight), respectively, in bearded seal. In general, {sup 137}Cs tissue concentrations are significantly lower than those previously reported for mammals from other regions. By comparison, {sup 210}Po activity concentrations appear to be higher than those reported elsewhere but a larger variation. The mean {sup 210}Po concentration in the muscle tissue, liver and kidney of Pacific walrus (N=5, wet weight) were 28.7, 189, and 174 Bq kg{sup -1}, respectively. This compares with {sup 210}Po concentration values (N=2, wet weight) of 27, 207, and 68 Bq kg{sup -1} measured in the muscle tissue, liver and kidney, of bearded seal, respectively. Estimated bioaccumulation factors--as defined by the radionuclide concentration ratio between the target tissue to that in sea water--were two to three orders of magnitude higher for …
Date: February 2, 2005
Creator: Hamilton, T F; Seagars, D J; Jokela, T & Layton, D
System: The UNT Digital Library
Abscisic acid regulates secondary cell-wall formation and lignin deposition in Arabidopsis thaliana through phosphorylation of NST1 (open access)

Abscisic acid regulates secondary cell-wall formation and lignin deposition in Arabidopsis thaliana through phosphorylation of NST1

Article using a combination of biochemical and genetic approaches to show how ABA can regulate lignin biosynthesis. This work provides a basis for designing trees and other biomass plants that are better adapted to stress and climate change. This article includes a correction on the first page.
Date: February 2, 2021
Creator: Liu, Chang; Yu, Hasi; Rao, Xiaolan; Li, Laigeng & Dixon, R. A.
System: The UNT Digital Library
Activity Coefficients at Infinite Dilution of Organic Compounds in Trihexyl(tetradecyl)phosphonium Bis(trifluoromethylsulfonyl)imide Using Inverse Gas Chromatography (open access)

Activity Coefficients at Infinite Dilution of Organic Compounds in Trihexyl(tetradecyl)phosphonium Bis(trifluoromethylsulfonyl)imide Using Inverse Gas Chromatography

Article on activity coefficients at infinite dilution of organic compounds in trihexyl(tetradecyl)phosphonium Bis(trifluoromethylsulfonyl)imide using inverse gas chromatography.
Date: February 2, 2009
Creator: Revelli, Anne-Laure; Sprunger, Laura M.; Gibbs, Jennifer; Acree, William E. (William Eugene); Baker, Gary A. & Mutelet, Fabrice
System: The UNT Digital Library
Adaptive Wavefront Calibration and Control for the Gemini Planet Imager (open access)

Adaptive Wavefront Calibration and Control for the Gemini Planet Imager

Quasi-static errors in the science leg and internal AO flexure will be corrected. Wavefront control will adapt to current atmospheric conditions through Fourier modal gain optimization, or the prediction of atmospheric layers with Kalman filtering.
Date: February 2, 2007
Creator: Poyneer, L A & Veran, J
System: The UNT Digital Library
Aging in financial market (open access)

Aging in financial market

Article discussing aging in the financial market.
Date: February 2, 2008
Creator: Bianco, Simone & Grigolini, Paolo
System: The UNT Digital Library
An analytical model of nonproportional scintillator light yield in terms of recombination rates (open access)

An analytical model of nonproportional scintillator light yield in terms of recombination rates

This report talks about An analytical model of nonproportional scintillator light yield in terms of recombination rates
Date: February 2, 2009
Creator: Bizarri, Gregory; Moses, William W.; Singh, Jai; Williams, Richard T. & Vasil'ev, Andrey N.
System: The UNT Digital Library
Application of dynamic linear regression to improve the skill of ensemble-based deterministic ozone forecasts (open access)

Application of dynamic linear regression to improve the skill of ensemble-based deterministic ozone forecasts

Forecasts from seven air quality models and surface ozone data collected over the eastern USA and southern Canada during July and August 2004 provide a unique opportunity to assess benefits of ensemble-based ozone forecasting and devise methods to improve ozone forecasts. In this investigation, past forecasts from the ensemble of models and hourly surface ozone measurements at over 350 sites are used to issue deterministic 24-h forecasts using a method based on dynamic linear regression. Forecasts of hourly ozone concentrations as well as maximum daily 8-h and 1-h averaged concentrations are considered. It is shown that the forecasts issued with the application of this method have reduced bias and root mean square error and better overall performance scores than any of the ensemble members and the ensemble average. Performance of the method is similar to another method based on linear regression described previously by Pagowski et al., but unlike the latter, the current method does not require measurements from multiple monitors since it operates on individual time series. Improvement in the forecasts can be easily implemented and requires minimal computational cost.
Date: February 2, 2006
Creator: Pagowski, M O; Grell, G A; Devenyi, D; Peckham, S E; McKeen, S A; Gong, W et al.
System: The UNT Digital Library
Atmospheric Dispersion Analysis using MACCS2 (open access)

Atmospheric Dispersion Analysis using MACCS2

The Nuclear Regulatory Commission (NRC) Regulatory Guide 1.145 requires an evaluation of the offsite atmospheric dispersion coefficient, {Chi}/Q, as a part of the acceptance criteria in the accident analysis. In it, it requires in sequence computations of (1) the overall site 95th percentile {Chi}/Q, (2) the maximum of the sixteen sector 99.5th percentile {Chi}/Q, and (3) comparison and selection of the worst of the two values for reporting in the safety analysis report (SAR). In all cases, the site-specific meteorology and sector-specific site boundary distances are employed in the evaluation. There are sixteen 22.5-sectors, the nearest site boundary of which is determined within the 45-arc centered on each of the sixteen compass directions.
Date: February 2, 2004
Creator: Glaser, R. & Yang, J. M.
System: The UNT Digital Library
Automatic Quenching of High Energy gamma-ray Sources by Synchrotron Photons (open access)

Automatic Quenching of High Energy gamma-ray Sources by Synchrotron Photons

Here we investigate evolution of a magnetized system, in which continuously produced high energy emission undergoes annihilation on a soft photon field, such that the synchrotron radiation of the created electron-positron pairs increases number density of the soft photons. This situation is important in high energy astrophysics, because, for an extremely wide range of magnetic field strengths (nano to mega Gauss), it involves {gamma}-ray photons with energies between 0.3GeV and 30TeV. We derive and analyze the conditions for which the system is unstable to runaway production of soft photons and ultrarelativistic electrons, and for which it can reach a steady state with an optical depth to photon-photon annihilation larger than unity, as well those for which efficient pair loading of the emitting volume takes place. We also discuss the application of our analysis to a realistic situation involving astrophysical sources of a broad-band {gamma}-ray emission and briefly consider the particular case of sources close to active supermassive black holes.
Date: February 2, 2007
Creator: Stawarz, Lukasz; /KIPAC, Menlo Park /SLAC /Jagiellonian U., Astron. Observ.; Kirk, John & /Heidelberg, Max Planck Inst.
System: The UNT Digital Library
Carbon contamination of extreme ultraviolet (EUV) mask and its effect on imaging (open access)

Carbon contamination of extreme ultraviolet (EUV) mask and its effect on imaging

Carbon contamination of extreme ultraviolet (EUV) masks and its effect on imaging is a significant issue due to lowered throughput and potential effects on imaging performance. In this work, a series of carbon contamination experiments were performed on a patterned EUV mask. Contaminated features were then inspected with a reticle scanning electron microscope (SEM) and printed with the SEMA TECH Berkeley Microfield-Exposure tool (MET) [1]. In addition, the mask was analyzed using the SEMA TECH Berkeley Actinic-Inspection tool (AIT) [2] to determine the effect of carbon contamination on the absorbing features and printing performance. To understand the contamination topography, simulations were performed based on calculated aerial images and resist parameters. With the knowledge of the topography, simulations were then used to predict the effect of other thicknesses of the contamination layer, as well as the imaging performance on printed features.
Date: February 2, 2009
Creator: Fan, Yu-Jen; Yankulin, Leonid; Antohe, Alin; Garg, Rashi; Thomas, Petros; Mbanaso, Chimaobi et al.
System: The UNT Digital Library
Ceramic breeder materials : status and needs. (open access)

Ceramic breeder materials : status and needs.

The tritium breeding blanket is one of the most important components of a fusion reactor because it directly involves both energy extraction and tritium production, both of which are critical to fusion power. Because of their overall desirable properties, lithium-containing ceramic solids are recognized as attractive tritium breeding materials for fusion reactor blankets. Indeed, their inherent thermal stability and chemical inertness are significant safety advantages. In numerous in-pile experiments, these materials have performed well, showing good thermal stability and good tritium release characteristics. Tritium release is particularly facile when an argon or helium purge gas containing hydrogen, typically at levels of about 0.1%, is used. However, the addition of hydrogen to the purge gas imposes a penalty when it comes to recovery of the tritium produced in the blanket. In particular, a large amount of hydrogen in the purge gas will necessitate a large multiple-stage tritium purification unit, which could translate into higher costs. Optimizing tritium release while minimizing the amount of hydrogen necessary in the purge gas requires a deeper understanding of the tritium release process, especially the interactions of hydrogen with the surface of the lithium ceramic. This paper reviews the status of ceramic breeder research and highlights …
Date: February 2, 1998
Creator: Johnson, C. E.
System: The UNT Digital Library
Cerocene Revisited: The Electronic Structure of and Interconversion Between Ce2(C8H8)3 and Ce(C8H8)2 (open access)

Cerocene Revisited: The Electronic Structure of and Interconversion Between Ce2(C8H8)3 and Ce(C8H8)2

New synthetic procedures for the preparation of Ce(cot)2, cerocene, from [Li(thf)4][Ce(cot)2], and Ce2(cot)3 in high yield and purity are reported. Heating solid Ce(cot)2 yields Ce2(cot)3 and COT while heating Ce2(cot)3 with an excess of COT in C6D6 to 65oC over four months yields Ce(cot)2. The solid state magnetic susceptibility of these three organocerium compounds shows that Ce(cot)2 behaves as a TIP (temperature independent paramagnet) over the temperature range of 5-300 K, while that of Ce2(cot)3 shows that the spin carriers are antiferromagnetically coupled below 10 K; above 10 K, the individual spins are uncorrelated, and [Ce(cot)2]- behaves as an isolated f1 paramagnet. The EPR at 1.5K for Ce2(cot)3 and [Ce(cot)2]- have ground state of MJ= +- 1/2. The LIII edge XANES of Ce(cot)2 (Booth, C.H.; Walter, M.D.; Daniel, M.; Lukens, W.W., Andersen, R.A., Phys. Rev. Lett. 2005, 95, 267202) and 2Ce2(cot)3 over 30-500 K are reported; the Ce(cot)2 XANES spectra show Ce(III) and Ce(IV) signatures up to a temperature of approximately 500 K, whereupon the Ce(IV) signature disappears, consistent with the thermal behavior observed in the melting experiment. The EXAFS of Ce(cot)2 and Ce2(cot)3 are reported at 30 K; the agreement between the molecular parameters for Ce(cot)2 derived from EXAFS …
Date: February 2, 2009
Creator: Walter, Marc D.; Booth, Corwin H.; Lukens, Wayne W. & Andersen, Richard A.
System: The UNT Digital Library
Certification of solar products - The Florida experience (open access)

Certification of solar products - The Florida experience

Florida legislation enacted in 1976 directed the Florida Solar Energy Center (FSEC) to develop standards for solar energy systems manufactured or sold in the state, establish criteria for testing the performance of solar energy systems, and provide a means to display compliance with approved performance tests for these systems. This mandate has been effectively implemented for both solar domestic water heating and solar pool heating systems. With growing interest and markets for photovoltaic systems, plans are presently being developed to expand the scope of the mandate to include photovoltaic technology. This paper discusses four complementary facets of a photovoltaic (PV) system certification program. They include PV module performance characterization and rating; PV system design review and approval; examination and authorization of photovoltaic system installers; and inspection and acceptance testing of PV system installation. The suggested photovoltaic system process builds on lessons learned from over 20 years of testing, certifying and labeling of solar thermal collectors, and the certification of solar thermal systems.
Date: February 2, 2000
Creator: POST,HAROLD N.; ROLAND,JAMES D.; VENTRE,GERARD G. & HUGGINS,JAMES C.
System: The UNT Digital Library
Chronic Inhibition of Mitochondrial Dihydrolipoamide Dehydrogenase (DLDH) as an Approach to Managing Diabetic Oxidative Stress (open access)

Chronic Inhibition of Mitochondrial Dihydrolipoamide Dehydrogenase (DLDH) as an Approach to Managing Diabetic Oxidative Stress

This article investigates if chronic inhibition of DLDH could also attenuate oxidative stress in type 2 diabetes. It is the authors' belief that DLDH inhibition could be a novel approach to fighting type 2 diabetes.
Date: February 2, 2019
Creator: Yang, Xiaojuan; Song, Jing & Yan, Liang-Jun
System: The UNT Digital Library
The Color Glass Condensate, Glasma and the Quark Gluon Plasma in the Context of Recent pPb Results from LHC (open access)

The Color Glass Condensate, Glasma and the Quark Gluon Plasma in the Context of Recent pPb Results from LHC

N/A
Date: February 2, 2013
Creator: McLerran, L.
System: The UNT Digital Library

Commentary on "Thermodynamic equilibrium of hydroxyacetic acid in pure and binary solvent systems"

This article discusses published mathematical representations by Huant et al. (2017) for describing how the measured mole fraction solubility varies with solvent composition in the binary (ethanol + ethyl acetate) and binary (acetone + ethanol) solvent systems.
Date: February 2, 2017
Creator: Acree, William E. (William Eugene)
System: The UNT Digital Library
A comparison of spin observable predictions for RHIC (open access)

A comparison of spin observable predictions for RHIC

There have been many versions of spin-dependent parton distributions in the literature. Although most agree with present data within uncertainties, they are based upon different physical assumptions. Some physical models are discussed and the corresponding predictions for double spin asymmetries are shown. A summary of the most feasible measurements in the appropriate kinematic regions at RHIC, which should yield the most useful information about the polarized gluon distribution, is given.
Date: February 2, 2000
Creator: Ramsey, G. P.
System: The UNT Digital Library
A Computational Model with Experimental Validation for DNA Flow in Microchannels (open access)

A Computational Model with Experimental Validation for DNA Flow in Microchannels

The authors compare a computational model to experimental data for DNA-laden flow in microchannels. The purpose of this work in progress is to validate a new numerical algorithm for viscoelastic flow using the Oldroyd-B model. The numerical approach is a stable and convergent polymeric stress-splitting scheme for viscoelasticity. They treat the hyperbolic part of the equations of motion with an embedded boundary method for solving hyperbolic conservation laws in irregular domains. They enforce incompressibility and evolve velocity and pressure with a projection method. The experiments are performed using epifluorescent microscopy and digital particle image velocimetry to measure velocity fields and track the conformation of biological macromolecules. They present results comparing velocity fields and the observations of computed fluid stress on molecular conformation in various microchannels.
Date: February 2, 2005
Creator: Nonaka, A; Gulati, S; Trebotich, D; Miller, G H; Muller, S J & Liepmann, D
System: The UNT Digital Library
Computational modeling of alloys at the atomic scale: from ab initio and thermodynamics to radiation-induced heterogeneous precipitation (open access)

Computational modeling of alloys at the atomic scale: from ab initio and thermodynamics to radiation-induced heterogeneous precipitation

We describe the path we are following in the development of a computational approach to simulate radiation damage in FeCr ferritic steels. In these alloys magnetism introduces an anomaly in the heat of formation of the solid solution that has implications on the way excess Cr precipitates in the {alpha}{prime} phase in presence of heterogeneities. These complexities represent a challenge for atomistic (empirical) approaches that we address: (i) by proposing a modified many body potential, (ii) by using a thermodynamic package that determines free energy and phase diagrams, and (iii) by using a displacement Monte Carlo code in the transmutation ensemble that can deal with millions of atoms in parallel computational environments. This approach predicts that grain boundaries, dislocations and free surfaces are not preferential sites for precipitation of {alpha}{prime}.
Date: February 2, 2007
Creator: Caro, A.; Caro, M.; Klaver, P.; Sadigh, B.; Lopasso, E. M. & Srivilliputhur, S. G.
System: The UNT Digital Library
Concrete polymer materials as alternate materials of construction for geothermal applications - field test evaluations (open access)

Concrete polymer materials as alternate materials of construction for geothermal applications - field test evaluations

A serious problem in the development of geothermal energy is the availability of durable and economical materials of construction for handling hot brine and steam. Hot brine and other aerated geothermal fluids are highly corrosive and they attack most conventional materials of construction. Brookhaven National Laboratory has been investigating the use of concrete polymer materials as alternate materials of construction for geothermal processes. To date, successful field tests have been demonstrated at the Geysers, US Bureau of Mines Corrosion Facility, and at the East Mesa Geothermal Facility. This is a survey of field and laboratory evaluations of concrete polymer materials which have been shown to be durable and economical as alternate materials of construction.
Date: February 2, 1979
Creator: Fontana, J.J. & Zeldin, A.
System: The UNT Digital Library
Conductor development for High Energy Physics - Plans and Status of the U.S. Program (open access)

Conductor development for High Energy Physics - Plans and Status of the U.S. Program

None
Date: February 2, 2000
Creator: Scanlan, R. M.
System: The UNT Digital Library
Configuration management at an environmental restoration DOE facility (Fernald) (open access)

Configuration management at an environmental restoration DOE facility (Fernald)

This report contains information about a meeting held to discuss the decontamination and decommissioning of the Fernald site in Ohio. This site contains two major types of waste. First is the legacy waste. This waste consists of the wastes which were left over from production which is stored in various drums and containers across the site. Second is the waste generated from the remedial activities.
Date: February 2, 1994
Creator: Beckett, C.; Pasko, W. & Kupinski, T.
System: The UNT Digital Library
Constrained blackbox optimization: The SEARCH perspective (open access)

Constrained blackbox optimization: The SEARCH perspective

Search and optimization in the context of blackbox objective function evaluation subject to blackbox constraints satisfaction is the thesis of this work. The SEARCH (Search Envisioned As Relation and Class Hierarchizing) framework introduced by Kargupta (1995) offered an alternate perspective of blackbox optimization in terms of relations, classes, and partial ordering. The primary motivation comes from the observation that sampling in blackbox optimization is essentially an inductive process and in the absence of any relation among the members of the search space, induction is no better than enumeration. SEARCH also offers conditions for polynomial complexity search and bounds on sample complexity using its ordinal, probabilistic, and approximate framework. In this work the authors extend the SEARCH framework to tackle constrained blackbox optimization problems. The methodology aims at characterizing the search domain into feasible and infeasible relations among which the feasible relations can be explored further to optimize an objective function. Both -- objective function and constraints -- can be in the form of blackboxes. The authors derive results for bounds on sample complexity. They demonstrate their methodology on several benchmark problems.
Date: February 2, 1996
Creator: Hanagandi, V.; Kargupta, H. & Buescher, K.
System: The UNT Digital Library
Creating Ensembles of Decision Trees Through Sampling (open access)

Creating Ensembles of Decision Trees Through Sampling

Recent work in classification indicates that significant improvements in accuracy can be obtained by growing an ensemble of classifiers and having them vote for the most popular class. This paper focuses on ensembles of decision trees that are created with a randomized procedure based on sampling. Randomization can be introduced by using random samples of the training data (as in bagging or arcing) and running a conventional tree-building algorithm, or by randomizing the induction algorithm itself. The objective of this paper is to describe our first experiences with a novel randomized tree induction method that uses a subset of samples at a node to determine the split. Our empirical results show that ensembles generated using this approach yield results that are competitive in accuracy and superior in computational cost.
Date: February 2, 2001
Creator: Kamath, C & Cantu-Paz, E
System: The UNT Digital Library