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Effect of light-delignification on mechanical, hydrophobic, and thermal properties of high-strength molded fiber materials (open access)

Effect of light-delignification on mechanical, hydrophobic, and thermal properties of high-strength molded fiber materials

This article discusses the development of a high-strength molded fiber material using pulp fibers, which coudl be a good substitute for plastic and solid wood materials.
Date: July 20, 2017
Creator: Wang, Quanliang; Xiao, Shengling; Shi, Sheldon Q. & Cai, Liping
System: The UNT Digital Library
ENHANCED CHEMICAL CLEANING: A NEW PROCESS FOR CHEMICALLY CLEANING SAVANNAH RIVER WASTE TANKS (open access)

ENHANCED CHEMICAL CLEANING: A NEW PROCESS FOR CHEMICALLY CLEANING SAVANNAH RIVER WASTE TANKS

The Savannah River Site (SRS) has 49 high level waste (HLW) tanks that must be emptied, cleaned, and closed as required by the Federal Facilities Agreement. The current method of chemical cleaning uses several hundred thousand gallons per tank of 8 weight percent (wt%) oxalic acid to partially dissolve and suspend residual waste and corrosion products such that the waste can be pumped out of the tank. This adds a significant quantity of sodium oxalate to the tanks and, if multiple tanks are cleaned, renders the waste incompatible with the downstream processing. Tank space is also insufficient to store this stream given the large number of tanks to be cleaned. Therefore, a search for a new cleaning process was initiated utilizing the TRIZ literature search approach, and Chemical Oxidation Reduction Decontamination--Ultraviolet (CORD-UV), a mature technology currently used for decontamination and cleaning of commercial nuclear reactor primary cooling water loops, was identified. CORD-UV utilizes oxalic acid for sludge dissolution, but then decomposes the oxalic acid to carbon dioxide and water by UV treatment outside the system being treated. This allows reprecipitation and subsequent deposition of the sludge into a selected container without adding significant volume to that container, and without adding …
Date: January 17, 2008
Creator: Ketusky, E; Neil Davis, N & Renee Spires, R
System: The UNT Digital Library
Numerical studies of fluid-rock interactions in EnhancedGeothermal Systems (EGS) with CO2 as working fluid (open access)

Numerical studies of fluid-rock interactions in EnhancedGeothermal Systems (EGS) with CO2 as working fluid

There is growing interest in the novel concept of operating Enhanced Geothermal Systems (EGS) with CO{sub 2} instead of water as heat transmission fluid. Initial studies have suggested that CO{sub 2} will achieve larger rates of heat extraction, and can offer geologic storage of carbon as an ancillary benefit. Fluid-rock interactions in EGS operated with CO{sub 2} are expected to be vastly different in zones with an aqueous phase present, as compared to the central reservoir zone with anhydrous supercritical CO{sub 2}. Our numerical simulations of chemically reactive transport show a combination of mineral dissolution and precipitation effects in the peripheral zone of the systems. These could impact reservoir growth and longevity, with important ramifications for sustaining energy recovery, for estimating CO{sub 2} loss rates, and for figuring tradeoffs between power generation and geologic storage of CO{sub 2}.
Date: January 17, 2008
Creator: Xu, Tianfu; Pruess, Karsten & Apps, John
System: The UNT Digital Library
Efficient computation of matched solutions of the KV envelope equations for periodic focusing lattices. (open access)

Efficient computation of matched solutions of the KV envelope equations for periodic focusing lattices.

A new iterative method is developed to numerically calculate the periodic, matched beam envelope solution of the coupled Kapchinskij-Vladimirskij (KV) equations describing the transverse evolution of a beam in a periodic, linear focusing lattice of arbitrary complexity. Implementation of the method is straightforward. It is highly convergent and can be applied to all usual parameterizations of the matched envelope solutions. The method is applicable to all classes of linear focusing lattices without skew couplings, and also applies to parameters where the matched beam envelope is strongly unstable. Example applications are presented for periodic solenoidal and quadrupole focusing lattices. Convergence properties are summarized over a wide range of system parameters.
Date: January 17, 2006
Creator: Lund, S M; Chilton, S H & Lee, E P
System: The UNT Digital Library
Metrologies for the Phase Characterization of Attosecond (open access)

Metrologies for the Phase Characterization of Attosecond

EUV optics play a key role in attosecond science since only with higher photon energies is it possible to achieve the wide spectral bandwidth required for ultrashort pulses. Multilayer EUV mirrors have been proposed and are being developed to temporally shape (compress) attosecond pulses. To fully characterize a multilayer optic for pulse applications requires not only knowledge of the reflectivity, as a function of photon energy, but also the reflected phase of the mirror. This work develops the metrologies to determine the reflected phase of an EUV multilayer mirror using the photoelectric effect. The proposed method allows one to determine the optic's impulse response and hence its pulse characteristics.
Date: January 17, 2008
Creator: CXRO
System: The UNT Digital Library
Heavy Quarkonium Production in Single Transverse Polarized HighEnergy Scattering (open access)

Heavy Quarkonium Production in Single Transverse Polarized HighEnergy Scattering

We formulate the single transverse spin asymmetry in heavyquarkoniumproduction in lepton-nucleon and nucleon-nucleon collisionsinthe non-relativistic limit. We findthat the asymmetry is very sensitiveto the production mechanism. The finalstate interactions with the heavyquark and antiquark cancel out among themselves whenthe pair are producedin a color-single configuration, or cancel out with the initialstateinteraction in pp scattering when they are in color-octet. As aconsequence, the asymmetry is nonzero in ep collisions only in thecolor-octet model, whereas in pp collisions only in the color-singletmodel.
Date: January 17, 2008
Creator: Yuan, Feng
System: The UNT Digital Library
Exaggerated Health Benefits of Physical Fitness and Activity dueto Self-selection. (open access)

Exaggerated Health Benefits of Physical Fitness and Activity dueto Self-selection.

Background: The predicted health benefits of becomingphysically active or fit will be exaggerated if health outcomes causefitness and activity rather than the converse in prospective andcross-sectional epidemiological studies. Objective: Assess whether therelationships of adiposity to fitness and activity are explained byadiposity prior to exercising. Design: Cross-sectional study of physicalfitness (running speed during 10km foot race) and physical activity(weekly running distance) to current BMI (BMIcurrent) and BMI at thestart of running (BMIstarting) in 44,370 male and 25,252 femaleparticipants of the National Runners' Health Study. Results: BMIstartingexplained all of the association between fitness and BMIcurrent in bothsexes, but less than a third of the association between physical activityand BMIcurrent in men. In women, BMIstarting accounted for 58 percent ofthe association between BMIcurrent and activity levels. The 95thpercentile of BMIcurrent showed substantially greater declines withfitness and activity levels than the 5th percentile of BMIcurrent in men(i.e., the negative slope for 95th percentile was 2.6-fold greater thanthe 5th percentile for fitness and 3-fold greater for activity) and women(6-fold and 3.4-fold greater, respectively). At all percentiles, theregression slopes relating BMIstarting to fitness were comparable orgreater (more negative) than the slopes relating BMIcurrent to fitness,whereas the converse was true for activity. Conclusion: Self-selectionbias accounts for all …
Date: January 17, 2006
Creator: Williams, Paul T.
System: The UNT Digital Library
Collins Asymmetry at Hadron Colliders (open access)

Collins Asymmetry at Hadron Colliders

We study the Collins effect in the azimuthal asymmetricdistribution of hadrons inside a high energy jet in the single transversepolarized proton proton scattering. From the detailed analysis ofone-gluon and two-gluon exchange diagrams contributions, the Collinsfunction is found the same as that in the semi-inclusive deep inelasticscattering and e+e- annihilations. The eikonal propagators in thesediagrams do not contribute to the phase needed for the Collins-typesingle spin asymmetry, and the universality is derived as a result of theWard identity. We argue that this conclusion depends on the momentum flowof the exchanged gluon and the kinematic constraints in the fragmentationprocess, and is generic and model-independent.
Date: January 17, 2008
Creator: Yuan, Feng
System: The UNT Digital Library
Dihadron Tomography of High-Energy Nuclear Collisions inNext-to-Leading Order Perturbative QCD (open access)

Dihadron Tomography of High-Energy Nuclear Collisions inNext-to-Leading Order Perturbative QCD

Back-to-back dihadron spectra in high-energy heavy-ioncollisions are studied within the next-to-leading order (NLO)perturbative QCD parton model with jet quenching incorporated viamodified jet fragmentation functions due to radiative parton energy lossin dense medium. The experimentally observed appearance of back-to-backdihadron sat high p_T is found to originate mainly from jet pairsproduced close and tangential to the surface of the dense matter.However, a substantial fraction of observed high p_T dihadrons also comesfrom jets produced at the center of the medium after losing finite amountof energy. Consequently, the suppression factor of such high-p_T hadronpairs is foundto be more sensitive to the initial gluon density than thesingle hadron spectra that are dominated by surface emission. Asimultaneous chi2-fit to both the single and dihadron spectra can beachieved within an arrow range of the energy loss parametersepsilon_0=1.6-2.1 GeV/fm. Because of the flattening of the initial jetproduction spectra, high p_T dihadrons at the LHC energy are found to bemore robust as probes of the dense medium.
Date: January 17, 2007
Creator: Zhang, Hanzhong; Owens, Joseph F.; Wang, Enke & Wang, Xin-Nian
System: The UNT Digital Library
Properties of Ellipticity Correlation with Atmospheric Structure From Gemini South (open access)

Properties of Ellipticity Correlation with Atmospheric Structure From Gemini South

Cosmic shear holds great promise for a precision independent measurement of {Omega}{sub m}, the mass density of the universe relative to the critical density. The signal is expected to be weak, so a thorough understanding of systematic effects is crucial. An important systematic effect is the atmosphere: shear power introduced by the atmosphere is larger than the expected signal. Algorithms exist to extract the cosmic shear from the atmospheric component, though a measure of their success applied to a range of seeing conditions is lacking. To gain insight into atmospheric shear, Gemini South imaging in conjunction with ground condition and satellite wind data were obtained. We find that under good seeing conditions Point-Spread-Function (PSF) correlations persist well beyond the separation typical of high-latitude stars. Under these conditions, ellipticity residuals based on a simple PSF interpolation can be reduced to within a factor of a few of the shot-noise induced ellipticity floor. We also find that the ellipticity residuals are highly correlated with wind direction. Finally, we correct stellar shapes using a more sophisticated procedure and generate shear statistics from stars. Under all seeing conditions in our data set the residual correlations lie everywhere below the target signal level. For good …
Date: January 17, 2007
Creator: Asztalos, Stephen J.; de Vries, W. H.; Rosenberg, L. J.; Treadway, T.; Burke, D.; Claver, C. et al.
System: The UNT Digital Library
Versatile laser glass inspection and damage testing facility (open access)

Versatile laser glass inspection and damage testing facility

A test facility is described which detects small opaque inclusions in large transparent components by using a commercial laser which delivers high energy pulses to the test sample at moderate frequency in a small diameter beam. The sample is automatically scanned such that each point in the volume is irradiated with ten pulses at twice the inclusion damage threshold - an amount sufficient to cause visible damage at inclusion sites. This approach permits detection of opaque inclusions in the parts per trillion and lower concentration range. The specifics of the device design and its performance are discussed in the context of automatic inclusion inspection and mapping in large laser optics.
Date: January 17, 1986
Creator: Marion, J. E.; Greiner, G. J.; Campbell, J. H.; Chaffee, P. H.; Hildum, J. S.; Grens, J. Z. et al.
System: The UNT Digital Library
Optimized flashlamp pumping of disc amplifiers (open access)

Optimized flashlamp pumping of disc amplifiers

Disk amplifier design for inertial fusion lasers has evolved with changing fusion-driver requirements from a primary emphasis on gain to a primary emphasis on efficiency. In this paper we compare Shiva and Nova amplifiers to a developmental amplifier (SSA) and show greater than a two-fold improvement in efficiency over past designs under all operating conditions. Experiments to optimize the efficiency of the SSA show that preionization of the flashlamps produces significant benefits and that the packing fraction of lamps is more important than the flashlamp reflector shape. They also show that the optimized flashlamp pulselength and reflector geometry depend on the desired stored energy in the laser medium. We have demonstrated a 7% storage efficiency at a stored fluence per disk of 0.5 J/cm/sup 2/ (stored energy density of 0.06 J/cm/sup 3/) and 4% at 2.0 J/cm/sup 2/ (0.25 J/cm/sup 3/). Comparison of SSA measurements with storage-efficiency calculations show that our flashlamp model accurately predicts the single-pass pumping of disk amplifiers. 24 refs., 22 figs.
Date: January 17, 1986
Creator: Murray, J. E.; Powell, H. T. & Woods, B. W.
System: The UNT Digital Library
Experiences with fast breeder reactor education in laboratory and short course settings (open access)

Experiences with fast breeder reactor education in laboratory and short course settings

The breeder reactor industry throughout the world has grown impressively over the last two decades. Despite the uncertainties in some national programs, breeder reactor technology is well established on a global scale. Given the magnitude of this technological undertaking, there has been surprisingly little emphasis on general breeder reactor education - either at the university or laboratory level. Many universities assume the topic too specialized for including appropriate courses in their curriculum - thus leaving students entering the breeder reactor industry to learn almost exclusively from on-the-job experience. The evaluation of four course presentations utilizing visual aids is presented.
Date: January 17, 1983
Creator: Waltar, A.E.
System: The UNT Digital Library
Time-implicit simulation of particle-fluid systems (open access)

Time-implicit simulation of particle-fluid systems

This paper presents one-dimensional particle-fluid hybrid simulations in which the strongly collisional components of the plasma (e.g., ions and thermal electrons with nu/sub cf/..delta..t > 1) are treated as fluids and the weakly collisional components (e.g., energetic electrons with nu/sub cp/..delta..t << 1) are treated as particles. Here nu/sub cf/ denotes the fluid ion and electron collision frequencies, nu/sub cp/ is the energetic particle collision frequency and ..delta..t is the time step. Collisions between particle and fluid components are treated by a Monte-Carlo method and mass transfers between the particle and fluid electron components are governed by collision frequency thresholds. The field is computed implicitly to allow time steps with ..omega../sub p/ ..delta..t > 1 (..omega../sub p/: plasma frequency).
Date: January 17, 1985
Creator: Denavit, J.
System: The UNT Digital Library
Beam propagation through a gaseous reactor: classical transport (open access)

Beam propagation through a gaseous reactor: classical transport

The present calculations are applicable to any beam geometry with cylindrical symmetry, including the converging beam geometry (large entrance port with radius > or approx. = 10 cm), as well as the pencil-shaped beam (small porthole with radius approx. mm). The small porthole is clearly advantageous from the reactor vessel design point of view. While the physics of the latter mode of propagation may be more complex, analyses up to this point have not revealed any detrimental instability effects that will inhibit propagation. In fact, the large perpendicular velocity v/sub perpendicular/ that the pinched mode can accommodate provides a mechanism for the quenching of filamentary instability. Furthermore, this mode of propagation can withstand more ion scattering and is not subject to the upper bound on pressure (p < 10 torr) which is imposed on the converging beam mode.
Date: January 17, 1979
Creator: Yu, S. S.; Buchanan, H. L.; Lee, E. P. & Chambers, F. W.
System: The UNT Digital Library
Development of a Waste Treatment Process to Deactivate Reactive Uranium Metal and Produce a Stable Waste Form (open access)

Development of a Waste Treatment Process to Deactivate Reactive Uranium Metal and Produce a Stable Waste Form

This paper highlights the results of initial investigations conducted to support the development of an integrated treatment process to convert pyrophoric metallic uranium wastes to a non-pyrophoric waste that is acceptable for land disposal. Several dissolution systems were evaluated to determine their suitability to dissolve uranium metal and that yield a final waste form containing uranium specie(s) amenable to precipitation, stabilization, adsorption, or ion exchange. During initial studies, one gram aliquots of uranium metal or the uranium alloy U-2%Mo were treated with 5 to 60 mL of selected reagents. Treatment systems screened included acids, acid mixtures, and bases with and without addition of oxidants. Reagents used included hydrochloric, sulfuric, nitric, and phosphoric acids, sodium hypochlorite, sodium hydroxide and hydrogen peroxide. Complete dissolution of the uranium turnings was achieved with the H{sub 3}PO{sub 4}/HCI system at room temperature within minutes. The sodium hydroxide/hydrogen peroxide, and sodium hypochlorite systems achieved complete dissolution but required elevated temperatures and longer reaction times. A ranking system based on criteria, such as corrosiveness, temperature, dissolution time, off-gas type and amount, and liquid to solid ratio, was designed to determine the treatment systems that should be developed further for a full-scale process. The highest-ranking systems, nitric acid/sulfuric …
Date: January 17, 2002
Creator: Gates-Anderson, D D; Laue, C A & Fitch, T E
System: The UNT Digital Library
VEGETATION COVER ANALYSIS OF HAZARDOUS WASTE SITES IN UTAH AND ARIZONA USING HYPERSPECTRAL REMOTE SENSING (open access)

VEGETATION COVER ANALYSIS OF HAZARDOUS WASTE SITES IN UTAH AND ARIZONA USING HYPERSPECTRAL REMOTE SENSING

Remote sensing technology can provide a cost-effective tool for monitoring hazardous waste sites. This study investigated the usability of HyMap airborne hyperspectral remote sensing data (126 bands at 2.3 x 2.3 m spatial resolution) to characterize the vegetation at U.S. Department of Energy uranium processing sites near Monticello, Utah and Monument Valley, Arizona. Grass and shrub species were mixed on an engineered disposal cell cover at the Monticello site while shrub species were dominant in the phytoremediation plantings at the Monument Valley site. The specific objectives of this study were to: (1) estimate leaf-area-index (LAI) of the vegetation using three different methods (i.e., vegetation indices, red-edge positioning (REP), and machine learning regression trees), and (2) map the vegetation cover using machine learning decision trees based on either the scaled reflectance data or mixture tuned matched filtering (MTMF)-derived metrics and vegetation indices. Regression trees resulted in the best calibration performance of LAI estimation (R{sup 2} &gt; 0.80). The use of REPs failed to accurately predict LAI (R{sup 2} &lt; 0.2). The use of the MTMF-derived metrics (matched filter scores and infeasibility) and a range of vegetation indices in decision trees improved the vegetation mapping when compared to the decision tree classification …
Date: January 17, 2012
Creator: Serrato, M.; Jungho, I.; Jensen, J.; Jensen, R.; Gladden, J. & Waugh, J.
System: The UNT Digital Library
A Note on Neutron Capture Correlation Signals, Backgrounds, and Efficiencies (open access)

A Note on Neutron Capture Correlation Signals, Backgrounds, and Efficiencies

None
Date: January 17, 2012
Creator: Bowden, N; Dazeley, S & Sweany, M
System: The UNT Digital Library
UV Laser Radiation: Skin Hazards and Skin Protection Controls (open access)

UV Laser Radiation: Skin Hazards and Skin Protection Controls

None
Date: January 17, 2013
Creator: Corbett, Jeff & Woods, Michael
System: The UNT Digital Library
A One System Integrated Approach to Simulant Selection for Hanford High Level Waste Mixing and Sampling Tests (open access)

A One System Integrated Approach to Simulant Selection for Hanford High Level Waste Mixing and Sampling Tests

The Hanford Tank Operations Contractor (TOC) and the Hanford Waste Treatment and Immobilization Plant (WTP) contractor are both engaged in demonstrating mixing, sampling, and transfer system capabilities using simulated Hanford High-Level Waste (HLW) formulations. This represents one of the largest remaining technical issues with the high-level waste treatment mission at Hanford. Previous testing has focused on very specific TOC or WTP test objectives and consequently the simulants were narrowly focused on those test needs. A key attribute in the Defense Nuclear Facilities Safety Board (DNFSB) Recommendation 2010-2 is to ensure testing is performed with a simulant that represents the broad spectrum of Hanford waste. The One System Integrated Project Team is a new joint TOC and WTP organization intended to ensure technical integration of specific TOC and WTP systems and testing. A new approach to simulant definition has been mutually developed that will meet both TOC and WTP test objectives for the delivery and receipt of HLW. The process used to identify critical simulant characteristics, incorporate lessons learned from previous testing, and identify specific simulant targets that ensure TOC and WTP testing addresses the broad spectrum of Hanford waste characteristics that are important to mixing, sampling, and transfer performance are …
Date: January 17, 2013
Creator: Thien, Mike G. & Barnes, Steve M.
System: The UNT Digital Library
Performance Metrics for Safe Laser Operations at SLAC National Accelerator Laboratory (open access)

Performance Metrics for Safe Laser Operations at SLAC National Accelerator Laboratory

None
Date: January 17, 2013
Creator: Woods, Michael
System: The UNT Digital Library
Decommissioning the Physics Laboratory, Building 777-10a, at the Savannah River Site (Srs) (open access)

Decommissioning the Physics Laboratory, Building 777-10a, at the Savannah River Site (Srs)

SRS recently completed a four-year mission to decommission {approx}250 excess facilities. As part of that effort, SRS decommissioned a 48,000 ft{sup 2} laboratory that housed four low-power test reactors, formerly used by SRS to determine reactor physics. This paper describes and reviews the decommissioning, with a focus on component segmentation and handling (i.e. hazardous material removal, demolition, and waste handling). The paper is intended to be a resource for engineers, planners, and project managers who face similar decommissioning challenges.
Date: January 17, 2007
Creator: Musall, J. & Cathy Sizemore, C.
System: The UNT Digital Library
Transversity GPD in photo- and electroproduction of two vectormesons (open access)

Transversity GPD in photo- and electroproduction of two vectormesons

The chiral-odd generalized parton distribution (GPD), or transversity GPD, of the nucleon can be accessed experimentally through the photo- or electroproduction of two vector mesons on a polarized nucleon target, {gamma}{sup (*)}N {yields} {rho}{sub 1}{rho}{sub 2}N', where {rho}{sub 1} is produced at large transverse momentum, {rho}{sub 2} is transversely polarized, and the mesons are separated by a large rapidity gap. We predict the cross section for this process for both transverse and longitudinal {rho}{sub 2} production. To this end we propose a model for the transversity GPDH{sub T}(x,{zeta},t), and give an estimate of the relative sizes of the transverse and longitudinal {rho}{sub 2}cross sections. We show that a dedicated experiment at high energy should be able to measure the transversity content of the proton.
Date: January 17, 2006
Creator: Enberg, Rikard; Pire, Bernard & Szymanowski, Lech
System: The UNT Digital Library