States

Raman spectroscopic studies of isotopic diatomic molecules and a technique for measuring stable isotope ratios using Raman scattering. [Cross sections] (open access)

Raman spectroscopic studies of isotopic diatomic molecules and a technique for measuring stable isotope ratios using Raman scattering. [Cross sections]

A method for measuring stable isotope ratios using Raman scattering has been developed. This method consists of simultaneously counting photons scattered out of a high-intensity laser beam by different isotopically-substituted molecules. A number of studies of isotopic diatomic molecules have been made. The Q-branches of the Raman spectra of the isotopic molecules /sup 14/N/sup 15/N and /sup 16/O/sup 18/O were observed at natural abundance in nitrogen and oxygen samples. Comparison of the ratios of the intensities of the Q-branches of the major nitrogen and oxygen isotopic molecules with mass spectrometric determinations of the isotopic compositions yielded scattering cross sections of /sup 14/N/sup 15/N relative to /sup 14/N/sup 14/N and /sup 16/O/sup 18/O relative to /sup 16/O/sup 16/O. These cross section ratios differ from unity, a difference which can be explained by considering nuclear mass effects on the Franck-Condon factors of the molecular transitions. The measured intensities of the /sup 14/N/sup 15/N and /sup 16/O/sup 18/O Q-branches provided the baseline data needed to make the previously-mentioned extrapolation. High-resolution (approximately 0.15 cm/sup -1/) spectra of the Q-branches of /sup 14/N/sup 14/N and /sup 16/O/sup 16/O yielded a direct determination of ..cap alpha../sub e/ (the difference between the rotational constant in the ground …
Date: May 25, 1976
Creator: Harney, R. C.
Object Type: Report
System: The UNT Digital Library
Final report on geological studies pertinent to site suitability criteria for high-level waste repositories (open access)

Final report on geological studies pertinent to site suitability criteria for high-level waste repositories

This document contains information on (1) the hydraulic conductivity of salt; (2) the various types of naturally occurring salt solution collapse features, and (3) the rate of formation of solution cavities in salt. (LK)
Date: May 25, 1977
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Synthesis of Accretion Disk and Nonthermal Source Models for AGN (open access)

Synthesis of Accretion Disk and Nonthermal Source Models for AGN

A scenario for the central engine of AGN has been developed consisting of a massive black hole (MBH) onto which gas accretes through an accretion disk. The accretion disk radiates the observed optical and ultraviolet continua. Surrounding the MBH is a nonthermal source which produces the infrared and soft x-ray continua by synchrotron emission, and the x-ray spectrum by inverse Compton scattering of the optical-ultraviolet photons from the accretion disk. Previously we modeled the accretion disk (M.A.M.) and nonthermal source (D.L.B.) separately, and here we combine the two models to form a unified description of the AGN engine. This combined model can be inverted to determine source parameters from observed spectra. A group of AGN for which multiband observations exist can then be modeled to: demonstrate the validity of the combined model for a large number of objects; establish the range of parameter values that describe the source; and search for any correlations between source description and type.
Date: May 25, 1988
Creator: Band, D. L. & Malkan, M. A.
Object Type: Article
System: The UNT Digital Library
Environmental considerations and regulations (open access)

Environmental considerations and regulations

Methods used to control the radiological impact of the nuclear fuel cycle are described. This control is exercised through the application of a series of federal laws and regulations that are used as the basis for licensing nuclear facilities. The control is exercised more directly by the use of radwaste treatment equipment at the nuclear facilities to limit the release of radioactive materials. Federal laws and regulations are summarized and their applications in licensing actions are discussed. Radiological doses from materials released from licensed facilities are compared with doses from natural background. A series of cost/benefit engineering surveys are being made to determine the cost and effectiveness of radwaste systems for decreasing the release of radioactive materials from model fuel cycle facilities and to determine the benefits in terms of reduction in dose commitment to individuals and populations in surrounding areas.
Date: May 25, 1976
Creator: Blanco, R. E.
Object Type: Article
System: The UNT Digital Library
Carbon Nanotube-Based Permeable Membranes: A Platform for Studying Nanofluidics (open access)

Carbon Nanotube-Based Permeable Membranes: A Platform for Studying Nanofluidics

A membrane of multiwalled carbon nanotubes embedded in a silicon nitride matrix was fabricated for use in studying fluid mechanics on the nanometer scale. Characterization by fluorescent tracer diffusion and scanning electron microscopy suggests that the membrane is void-free near the silicon substrate on which it rests, implying that the hollow core of the nanotube is the only conduction path for molecular transport. Nitrogen flow measurements of a nanoporous silicon nitride membrane, fabricated by sacrificial removal of carbon, give a flow rate of 0.086 cc/sec. Calculations of water flow across a nanotube membrane give a rate of 2.1x10{sup -6} cc/sec (0.12 {micro}L/min).
Date: May 25, 2004
Creator: Holt, J K; Park, H G; Noy, A; Huser, T; Eaglesham, D & Bakajin, O
Object Type: Article
System: The UNT Digital Library
Charged Higgs bosons in the transition region M{sub H{sup {+-}}} {approx} m{sub t} at the LHC (open access)

Charged Higgs bosons in the transition region M{sub H{sup {+-}}} {approx} m{sub t} at the LHC

We illustrate preliminary results obtained through Monte Carlo (HERWIG) and detector (ATLFAST) simulations of the H{sup {+-}} {yields} {tau}{sup {+-}}{nu}{sub {tau}} signature of charged Higgs bosons with masses comparable to that of the top quark.
Date: May 25, 2003
Creator: ASSAMAGAN,K. A. GUCHAIT,M. MORETTI,S.
Object Type: Article
System: The UNT Digital Library
V-1 TRANSITION AND N-VALUE OF MULTIFILAMENTARY LTS AND HTS WIRES AND CABLES. (open access)

V-1 TRANSITION AND N-VALUE OF MULTIFILAMENTARY LTS AND HTS WIRES AND CABLES.

For low T, multifilamentary conductors like NbTi and Nb{sub 3}Sn, the V-I transition to the normal state is typically quantified by the parameter, n, defined by ({rho}/{rho}{sub c})= (I/I{sub c}){sup n}. For NbTi, this parameterization has been very useful in the development of high Jc wires, where the n-value is regarded as an index of the filament quality. In copper-matrix wires with undistorted filaments, the n-value at 5T is {approx} 40-60, and drops monotonically with increasing field. However, n can vary significantly in conductors with higher resistivity matrices and those with a low copper fraction. Usually high n-values are associated with unstable resistive behavior and premature quenching. The n-value in NbTi Rutherford cables, when compared to that in the wires is useful in evaluating cabling degradation of the critical current due to compaction at the edges of the cable. In Nb{sub 3}Sn wires, n-value has been a less useful tool, since often the resistive transition shows small voltages {approx} a few {mu}V prior to quenching. However, in ''well behaved'' wires, n is {approx} 30-40 at 12T and also shows a monotonic behavior with field. Strain induced I{sub c} degradation in these wires is usually associated with lower n-values. For high …
Date: May 25, 2003
Creator: GHOSH,A. K.
Object Type: Article
System: The UNT Digital Library
Saturation of impurity-rich phases in a cerium-substituted pyrochlore-rich titanate ceramic: part 1 experimental results (open access)

Saturation of impurity-rich phases in a cerium-substituted pyrochlore-rich titanate ceramic: part 1 experimental results

The saturation of impurity-rich accessory phases in a Ce-analog baseline ceramic formulation for the immobilization of excess plutonium has been tested by synthesizing an impurity-rich baseline compositions at 1300 C, 1350 C, and 1400 C in air. Impurity oxides are added at the 10 wt% level. The resulting phases assemblages are typically rich in pyrochlore, Hf-zirconolite (hafnolite), brannerite and rutile, but in many instances also contain an accessory mineral enriched in the impurity oxide. The concentration of that oxide in coexisting pyrochlore sets the saturation limit for solid solution of the component in question. In most cases, the accessory phase does not contain significant amounts of Ce, Gd or U. Exceptions are the stabilization of a Ca-lanthanide phosphate and a phosphate glass when P{sub 2}O{sub 5} is added to the formulation. P{sub 2}O{sub 5} addition is also very effective in reducing the modal amount of pyrochlore in the form relative to brannerite. Addition of the sodium-aluminosilicate, NaAlSiO{sub 4}, also results in the formation of a grain boundary melt at run conditions, but the fate of this phase on cooling is not well determined. At temperatures above 1300 C, addition of 10 wt% Fe{sub 2}O{sub 3} also leads to melting. Substitution …
Date: May 25, 2000
Creator: Ryerson, F. J.; Ebbinghaus, B.; Kirkorian, O. & VanKonynenburg, R.
Object Type: Report
System: The UNT Digital Library
Interferometric resolution boosting for spectrographs (open access)

Interferometric resolution boosting for spectrographs

Externally dispersed interferometry (EDI) is a technique for enhancing the performance of spectrographs for wide bandwidth high resolution spectroscopy and Doppler radial velocimetry. By placing a small angle-independent interferometer near the slit of a spectrograph, periodic fiducials are embedded on the recorded spectrum. The multiplication of the stellar spectrum times the sinusoidal fiducial net creates a moir{acute e} pattern, which manifests high detailed spectral information heterodyned down to detectably low spatial frequencies. The latter can more accurately survive the blurring, distortions and CCD Nyquist limitations of the spectrograph. Hence lower resolution spectrographs can be used to perform high resolution spectroscopy and radial velocimetry. Previous demonstrations of {approx}2.5x resolution boost used an interferometer having a single fixed delay. We report new data indicating {approx}6x Gaussian resolution boost (140,000 from a spectrograph with 25,000 native resolving power), taken by using multiple exposures at widely different interferometer delays.
Date: May 25, 2004
Creator: Erskine, D J & Edelstein, J
Object Type: Article
System: The UNT Digital Library
Pyrochlore-rich titanate ceramics for the immobilization of plutonium: redox effects on phase equilibria in cerium- and thorium- substituted analogs (open access)

Pyrochlore-rich titanate ceramics for the immobilization of plutonium: redox effects on phase equilibria in cerium- and thorium- substituted analogs

Three compositions representing plutonium-free analogs of a proposed Ca-Ti-Gd-Hf-U-PU oxide ceramic for the immobilization of plutonium were equilibrated at 1 atm, 1350 C over a range of oxygen fugacities between air and that equivalent to the iron-wuestite buffer. The cerium analog replaces Pu on a mole-per-mole basic with Ce; the thorium analog replaces Pu with Th. A third material has 10 wt% Al{sub 2}O{sub 3} added to the cerium analog to encourage the formation of a Hf-analog of, CaHfTi{sub 2}O{sub 7}, zirconolite, which is referred to as hafnolite. The predominant phase produced in each formulation under all conditions is pyrochlore, A{sub 2}T{sub 2}O{sub 7}, where the T site is filled by Ti, and Ca, the lanthanides, Hf, U and Pu are accommodated on the A-site. Other lanthanide and uranium-bearing phases encountered include brannerite (UTi{sub 2}O{sub 6}), hafnolite (CaHfTi{sub 2}O{sub 7}), perovskite (CaTiO{sub 3}) and a calcium-lanthanide aluminotitanate with nominal stoichiometry (Ca,Ln)Ti{sub 2}Al{sub 9}O{sub 19}, where Ln is a lanthanide. The phase compositions show progressive shifts with decreasing oxygen fugacity. All of the phases observed have previously been identified in titanate-based high-level radioactive waste ceramics and demonstrate the flexibility of these ceramics to variations in processing parameters. The main variation is …
Date: May 25, 2000
Creator: Ryerson, F. J. & Ebbinghaus, B.
Object Type: Report
System: The UNT Digital Library
Calculating Expectations with Time-Dependent Perturbations in Quantum Monte Carlo (open access)

Calculating Expectations with Time-Dependent Perturbations in Quantum Monte Carlo

None
Date: May 25, 2004
Creator: Kalos, M H & de Saavedra, F A
Object Type: Article
System: The UNT Digital Library
Coping With Contaminated Sediments and Soils in the Urban Environment. (open access)

Coping With Contaminated Sediments and Soils in the Urban Environment.

Soils and sediments contaminated with toxic organic and inorganic compounds harmful to the environment and to human health are common in the urban environment. We report here on aspects of a program being carried out in the New York/New Jersey Port region to develop methods for processing dredged material from the Port to make products that are safe for introduction to commercial markets. We discuss some of the results of the program in Computational Environmental Science, Laboratory Environmental Science, and Applied Environmental Science and indicate some possible directions for future work. Overall, the program elements integrate the scientific and engineering aspects with regulatory, commercial, urban planning, local governments, and community group interests. Well-developed connections between these components are critical to the ultimate success of efforts to cope with the problems caused by contaminated urban soils and sediments.
Date: May 25, 2004
Creator: Jones, K. W.; Van Der Lelie,D.; Mcguigan, M. & Al., Et
Object Type: Article
System: The UNT Digital Library
Ultrasonic Examination of Double-Shell Tank 241-SY-101. Examination Completed March 2004. (open access)

Ultrasonic Examination of Double-Shell Tank 241-SY-101. Examination Completed March 2004.

COGEMA Engineering Corporation (COGEMA), under a contract from CH2M Hill Hanford Group (CH2M Hill), has performed an ultrasonic nondestructive examination of selected portions of Double-Shell Tank 241-SY-101. The purpose of this examination was to provide information that could be used to evaluate the integrity of the wall of the primary tank. The requirements for the ultrasonic examination of Tank 241-SY-101 were to detect, characterize (identify, size, and locate), and record measurements made of any wall thinning, pitting, or cracks that might be present in the wall of the primary tank. Any measurements that exceed the requirements set forth in the Engineering Task Plan (ETP), RPP-17750 (Jensen 2003) and summarized on page 1 of this document, are reported to CH2M Hill and the Pacific Northwest National Laboratory (PNNL) for further evaluation. Under the contract with CH2M Hill, all data is to be recorded on disk and paper copies of all measurements are provided to PNNL for third-party evaluation. PNNL is responsible for preparing a report that describes the results of the COGEMA ultrasonic examinations.
Date: May 25, 2004
Creator: Pardini, Allan F. & Posakony, Gerald J.
Object Type: Report
System: The UNT Digital Library
IN PLANE OPTICAL RESPONSE OF UNDERDOPED La{sub 2-x}(Ca,Sr){sub x}CaCu{sub 2}O{sub 6+D} SINGLE CRYSTALS : EVIDENCE FOR INTRINSIC INHOMOGENEITY. (open access)

IN PLANE OPTICAL RESPONSE OF UNDERDOPED La{sub 2-x}(Ca,Sr){sub x}CaCu{sub 2}O{sub 6+D} SINGLE CRYSTALS : EVIDENCE FOR INTRINSIC INHOMOGENEITY.

The in-plane optical properties of two crystals of the bilayer cuprate La{sub 2-x}(Ca,Sr){sub x}Ca,Sr){sub x}CaCu{sub 2}O{sub 6+{delta}}, one with excess Ca and x = 0.10 and the other with Sr and x = 0.15, were investigated over the frequency range of 45-25000 cm{sup -1}. A metallic response both in frequency and temperature was observed for Sr = 0.15 superconducting sample at low frequencies. Meanwhile, the sample also exhibits a prominent charge-transfer excitation at around 15000 cm{sup -1}. This observation, together with neutron experiments performed on the same sample showing diffuse, elastic antiferromagnetic scattering, indicate that the quasi-mobile carriers coexist at low temperature with static antiferromagnetic clusters. This coexistence indicates intrinsic spatial inhomogeneity.
Date: May 25, 2003
Creator: WANG,N. L. ZHENG,P. FENG,T. GU,G. D. HOMES,C. C. TRANQUADA,J. M. GAULIN,B. D. TIMUSK,T.
Object Type: Article
System: The UNT Digital Library
A "First Principles" Potential Energy Surface for Liquid Water from VRT Spectroscopy of Water Clusters (open access)

A "First Principles" Potential Energy Surface for Liquid Water from VRT Spectroscopy of Water Clusters

We present results of gas phase cluster and liquid water simulations from the recently determined VRT(ASP-W)III water dimer potential energy surface. VRT(ASP-W)III is shown to not only be a model of high ''spectroscopic'' accuracy for the water dimer, but also makes accurate predictions of vibrational ground-state properties for clusters up through the hexamer. Results of ambient liquid water simulations from VRT(ASP-W)III are compared to those from ab initio Molecular Dynamics, other potentials of ''spectroscopic'' accuracy, and to experiment. The results herein represent the first time that a ''spectroscopic'' potential surface is able to correctly model condensed phase properties of water.
Date: May 25, 2004
Creator: Goldman, N.; Leforestier, C. & Saykally, R. J.
Object Type: Article
System: The UNT Digital Library
Interactions between Liquid-Wall Vapor and Edge Plasmas (open access)

Interactions between Liquid-Wall Vapor and Edge Plasmas

The use of liquid walls for fusion reactors could help solve problems associated with material erosion from high plasma heat-loads and neutronic activation of structures. A key issue analyzed here is the influx of impurity ions to the core plasma from the vapor of liquid side-walls. Numerical 2D transport simulations are performed for a slab geometry which approximates the edge region of a reactor-size tokamak. Both lithium vapor (from Li or SnLi walls) and fluorine vapor (from Flibe walls) are considered for hydrogen edge-plasmas in the high- and low-recycling regimes. It is found that the minimum influx is from lithium with a low-recycling hydrogen plasma, and the maximum influx occurs for fluorine with a high-recycling hydrogen plasma.
Date: May 25, 2000
Creator: Rognlien, T D & Rensink, M E
Object Type: Article
System: The UNT Digital Library
Production test number 105-519-E -- Raising permissible outlet water temperatures of selected tubes at C Pile (open access)

Production test number 105-519-E -- Raising permissible outlet water temperatures of selected tubes at C Pile

This report describes the objective of this production test which is to simulate with a few tubes operation of the old piles with small water annulus at power levels in the range of 800--900 MW.
Date: May 25, 1953
Creator: Goldsmith, S.
Object Type: Report
System: The UNT Digital Library
Cratering rates from lunar xenospherules (open access)

Cratering rates from lunar xenospherules

The goal of this project is to obtain the time history of impacts on the moon, with emphasis on recent impacts. In particular, the project could prove (or disprove) the existence of comet sores and provide the dates when they occurred.
Date: May 25, 1993
Creator: Muller, R. A.
Object Type: Report
System: The UNT Digital Library
Simulations of spectral broadening by cross-phase modulation (XPM) with chaotic light pulses (open access)

Simulations of spectral broadening by cross-phase modulation (XPM) with chaotic light pulses

Spectral broadening of single-frequency laser pulses by optical cross-phase modulation (XPM) with chaotic laser pulses in birefringent single-mode optical fibers is investigated numerically and results are compared with experiments. By this process we have generated laser pulses of variable bandwidth (1--25 {Angstrom}) at the fundamental wavelength (1053 nm) for amplification in high power solid-state Nd:glass lasers used for inertial confinement fusion research. Simulations indicate that a temporally smooth XPM pulse can be generated with intensity fluctuations of less than 10% and spectral width greater than 50 {Angstrom} using a short length ({approximately}5 m) of special low dispersion and low birefringence fiber, e.g. D = 10 ps/nm-km (normal dispersion) and {Delta}n = 2 {times} 10{sup {minus}5}. Readily available fibers of similar length, with parameters of D = 40 ps/nm-km and {Delta}n = 6 {times} 10{sup {minus}5}, can give spectral widths exceeding 25 {Angstrom}, but the noise will range from 25 to 60%. Broadband laser pulses generated by XPM are now routinely used at Lawrence Livermore National Laboratory for active smoothing of the laser irradiance on targets by the technique of smoothing-by-spectral dispersion.
Date: May 25, 1993
Creator: Henesian, M. A.; Dixit, S. N.; Chen, C. J.; Wai, P. K. A. & Menyuk, C. R.
Object Type: Article
System: The UNT Digital Library
XNJ140E Nuclear Turbojet, Section 5, Shield; Section 6, Turbomachinery; Section 7. Control System (open access)

XNJ140E Nuclear Turbojet, Section 5, Shield; Section 6, Turbomachinery; Section 7. Control System

This volume is one of twenty-one summarizing the Aircraft Nuclear Propulsion Program of the General Electric Company.
Date: May 25, 1962
Creator: Layman, D. C.
Object Type: Report
System: The UNT Digital Library
Development of a membrane-based process for the treatment of oily waste waters. Final report, March 4, 1992--March 5, 1994 (open access)

Development of a membrane-based process for the treatment of oily waste waters. Final report, March 4, 1992--March 5, 1994

This is a final report from Bend Research, Inc., (BRI) to the U.S. Department of Energy (DOE) for work performed under Contract No. DE-AC22-92MT92005, titled {open_quotes}Development of a Membrane-Based Process for the Treatment of Oily Waste Waters.{close_quotes} This report covers the period from March 4, 1992, to March 5, 1994. The overall goal of this program was to develop an economical oily-water treatment system based on reverse osmosis (RO). The RO system would be used to (1) reduce oil production costs by reducing the volume of waste water that must be disposed of, (2) form the basis of a generic waste-water treatment system that can easily be integrated into oil-field operations, especially at production facilities that are small or in remote locations; and (3) produce water clean enough to meet existing and anticipated environmental regulations. The specific focus of this program was the development of a hollow-fiber membrane module capable of treating oily waste waters.
Date: May 25, 1994
Creator: McCray, S. B.
Object Type: Report
System: The UNT Digital Library
Flow test: CG-482 ``DR type`` rear pigtail with B, D, DR and F pile fittings (open access)

Flow test: CG-482 ``DR type`` rear pigtail with B, D, DR and F pile fittings

This letter transmits the data from the 189-D Hydraulics Laboratory flow test on three CG-482 rear pigtails. The tests were run with a standard B, D, Dr and F rear nozzle and rear Parker fitting over the range of flows and temperatures anticipated for early CG-558 operation. The data from the test are given. All three pigtails gave essentially identical results. For comparison the results of previous tests with present rear pigtails are also plotted.
Date: May 25, 1956
Creator: Bell, K. J.
Object Type: Report
System: The UNT Digital Library
Waste simulant development for evaluation of LLW melter system technology (open access)

Waste simulant development for evaluation of LLW melter system technology

This document describes the LLW simulant compositions, basis for the simulants, and recipes for preparing nonradioactive simulants for LLW melter tests.
Date: May 25, 1994
Creator: Shade, J. W.
Object Type: Report
System: The UNT Digital Library
Electric power monthly, May 1993 (open access)

Electric power monthly, May 1993

The Electric Power Monthly (EPM) is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. This publication provides monthly statistics at the US, Census division, and State levels for net generation, fossil fuel consumption and stocks, quantity and quality of fossil fuels, cost of fossil fuels, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on net generation, fuel consumption, fuel stocks, quantity and cost of fossil fuels are also displayed for the North American Electric Reliability Council (NERC) regions.
Date: May 25, 1993
Creator: unknown
Object Type: Report
System: The UNT Digital Library