ARM tropical pacific experiment (ATPEX): Role of cloud, water vapor and convection feedbacks in the coupled ocean/atmosphere system (open access)

ARM tropical pacific experiment (ATPEX): Role of cloud, water vapor and convection feedbacks in the coupled ocean/atmosphere system

We have initiated studies that include radiation model validation, improved treatment of the three-dimensional structure of cloud-radiation interactions, and sensitivity runs that will unravel the role of cloud-convection-radiation interactions in the Pacific Sear Surface Temperatures and the overlying Walker and Hadley circulation. The research program is divided into three phases: (1) radiation, (2) cloud parameterization issues; (3) feedback and ocean-atmosphere interactions.
Date: March 5, 1992
Creator: Ramanathan, V. & Barnett, T.P.
Object Type: Report
System: The UNT Digital Library
Readily implemented enhanced sinusoid detection in noise (open access)

Readily implemented enhanced sinusoid detection in noise

Significant efforts have been devoted, spanning many years, to the problem of sinusoid detection in noise. Many of these efforts have produced superb, yet complex, algorithms which may be difficult to use for a wide segment of the Digital Signal Processing (DSP) community. This paper presents a simple, easily implemented and high effective method which solves this problem. This method severely degrades non-sinusoidal noise while leaving the embedded sinusoid(s) relatively undisturbed. The algorithm, simply put, exploits the difference between the net effect of integration and differentiation of sinusoids versus the effect of these operations on random noise and other signal sequences. The cross-correlation of sine wave with its differentiated (and/or integrated) self is quite high. Conversely, the cross-reduction of a noise sequence with its differentiated (and/or integrated) self is much lower. Therefore, it is reasonable to assume that for sequences consisting of a sinusoid in noise, significant signal-to-noise-ratios (SNRs) in the correlation results are achievable using a combination of differentiation (and/or integration) and cross-correlation operations on such sequences. This technique has been applied to actual Doppler radar data, as well as to synthesized data, with excellent improvement in signal detection capability. 4 refs.
Date: March 5, 1992
Creator: Lindsay, K.V.
Object Type: Report
System: The UNT Digital Library
Cultural noise in EM prospecting for geothermal resources. Final report (open access)

Cultural noise in EM prospecting for geothermal resources. Final report

Numerical analysis tools are used to characterize the fields reradiated by cultural scatterers like powerlines, pipelines and fences. These fields are then compared to the returns expected from deeply buried targets and suggestions are made for methods to identify and remove cultural noise from survey data.
Date: February 5, 1981
Creator: Merewether, D.E.; Cox, R.W. & Pate, R.C.
Object Type: Report
System: The UNT Digital Library
Cryopumping system for TFTR neutral beam injectors (open access)

Cryopumping system for TFTR neutral beam injectors

The cryocondensation pumping system for the TFTR neutral beam injectors is described. Topics include hardware design, differential pumping and beam loss, operational modes, and response to massive vacuum breaks.
Date: October 5, 1977
Creator: Valby, L.E.
Object Type: Article
System: The UNT Digital Library
Powerplant Productivity. Improvement Study: current practices in Illinois utilities towards powerplant productivity. Final report, Project 1, Task 1 (open access)

Powerplant Productivity. Improvement Study: current practices in Illinois utilities towards powerplant productivity. Final report, Project 1, Task 1

Efforts of this task indicate that powerplant productivity is a complex issue that has to take into account economic factors, equipment limitations, and system-loading characteristics as well as external constraints such as regulatory requirements. Among the specific findings are: (1) utilities in Illinois use the industry-wide measures of performance such as capacity factor, availability factor, forced outage rates etc.; equivalent availability as a measure is not in common practice; (2) several unit performance statistics are collected on a routine basis such as the daily unit status, component outage data, monthly production figures etc.; (3) identifying major causes of lost productivity appears to be a relatively simple task, but finding economically and technically acceptable corrective actions are generally more difficult; (4) selection of improvement projects, as well as evaluating their future impacts, is mostly based on operating experience and engineering judgement, with no use of formal analytical/statistical models; (5) there generally is a group in every utility - typically called the power production department - with routine responsibilities for upkeep of unit productivity; and (6) recently the Commonwealth Edison Co. has developed a procedure for utilizing the Edison Electric Institute outage data base for analyzing productivity-related questions at nuclear plants; this …
Date: April 5, 1979
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Application of digital image analysis techniques to the Geyser's data and topography (open access)

Application of digital image analysis techniques to the Geyser's data and topography

This paper describes the results of digital image analysis and techniques applied to acoustic sounder data and topographic relief in the Geyser's region. The two dimensional fast Fourier transform (2DFFT) represents the spacial variability of a photographic image. The spacial variability of topography in complex terrain can be represented in this way and insight into degree of complexity and dominating spacial wavelengths can be gained. This was performed for a 16 km square digitized topographic map of the Geyser's region with 63.5 m resolution. It was also of interest to compare facsimile recordings of acoustic sounder data to optical turbulence measurements.
Date: May 5, 1980
Creator: Porch, W.M.
Object Type: Article
System: The UNT Digital Library
Mechanisms of defect production and atomic mixing in high energy displacement cascades: A molecular dynamics study (open access)

Mechanisms of defect production and atomic mixing in high energy displacement cascades: A molecular dynamics study

We have performed molecular dynamics computer simulation studies of displacement cascades in Cu at low temperature. For 25 keV recoils we observe the splitting of a cascade into subcascades and show that cascades in Cu may lead to the formation of vacancy and interstitial dislocation loops. We discuss a new mechanism of defect production based on the observation of interstitial prismatic dislocation loop punching from cascades at 10 K. We also show that below the subcascade threshold, atomic mixing in the cascade is recoil-energy dependent and obtain a mixing efficiency that scales as the square root of the primary recoil energy. 44 refs., 12 figs.
Date: June 5, 1991
Creator: Diaz de la Rubia, T. & Guinan, M.W.
Object Type: Article
System: The UNT Digital Library
Development of an x-ray framing camera (open access)

Development of an x-ray framing camera

We are presently developing an ultrafast x-ray framing camera, to be used in laser fusion experiments on the NOVA facility at LLNL. The framing camera will provide high-fidelity images with frame durations of less than 100 ps. The first prototype camera will generate a single image approximately one square centimeter in area, with a spatial resolution of approx.30 microns at the image plane. Coupling the framing camera to a 22 x Wolter x-ray microscope will provide resolution at the target of approx.2 microns. The camera will be optically triggered using a laser pulse that is synchronous with the NOVA driver beams.
Date: March 5, 1986
Creator: Stearns, D.G.; Wiedwald, J.; Cook, B.M. & Hanks, R.
Object Type: Article
System: The UNT Digital Library
EDOT: a code to calculate charge particle slowing down in a plasma (open access)

EDOT: a code to calculate charge particle slowing down in a plasma

EDOT is a code that calculates the slowing down of a test particle in a Maxwellian plasma utilizing continuous slowing down theory. Both nuclear scattering and reactions are included. The output includes slowing down parameters as well as spectra of knock-on ions and in-flight reaction probabilities. The theory, input, and output for the code are described.
Date: August 5, 1977
Creator: Perkins, S. T.
Object Type: Report
System: The UNT Digital Library
Development of low level liquid waste treatment systems: April-September 1981 (open access)

Development of low level liquid waste treatment systems: April-September 1981

The pilot plant reverse osmosis system was demonstrated to be effective in removing large percentages of cobalt-60, iodine-125, and a mixture of cesium-137, cobalt-60, and iodine-125 from two types of aqueous streams. The effectiveness of three membrane porosities, 0, 50, and 97% salt rejection, were explored with each isotope. The 97% salt rejection membrane was the most effective in each experiment. Removals as high as 97.5% of the cobalt, 92.9% of the iodine and 95.1% of the combined isotopes were achieved. The effect of possibly interfering factors on the adsorbence of cobalt-60 and iodine-129 on selected ion exchange resins were investigated. The factors thought to affect cobalt-60 adsorption were (OH/sup -/), (NH/sub 4//sup +/), and (SO/sub 3//sup =/). None of the seven factors investigated had any effect on iodine-129 adsorption. Cesium-137 was removed from a 4600-gal aqueous waste containing a large amount of sodium hydroxide by treatment with sodium tetraphenyl boron. The cesium concentration of the supernatant portion was reduced from 570 to 4 counts/min/ml.
Date: March 5, 1982
Creator: Williams, M.K.; Colvin, C.M. & Bond, W.H.
Object Type: Report
System: The UNT Digital Library
Recent developments in nuclear reaction theories and calculations (open access)

Recent developments in nuclear reaction theories and calculations

A brief review is given of some recent developments in the fields of optical model potentials; level densities; and statistical model, precompound, and direct reaction codes and calculations. Significant developments have occurred in all of these fields since the 1977 Conference on Neutron Cross Sections, which will greatly enhance the ability to calculate high-energy neutron-induced reaction cross sections in the next few years. 11 figures, 3 tables.
Date: May 5, 1980
Creator: Gardner, D. G.
Object Type: Article
System: The UNT Digital Library
Low-temperature hydrothermal resource evaluation (open access)

Low-temperature hydrothermal resource evaluation

The objectives of testing low-temperature hydrothermal wells are to characterize well response to production (injection), determine resource characteristics and project reservoir longevity. Testing procedures and analysis techniques differ in some respects from proven procedures in the oil and gas and ground water fields. Some basic definitions and standard techniques necessary for the evaluation of a fluid resource in an intergranular permeable reservoir are presented. Problems particular to a non-ideal thermal resource are outlined and some analytical techniques are discussed.
Date: May 5, 1980
Creator: Goldman, D.
Object Type: Article
System: The UNT Digital Library
Nickel--chromium strain gages for cryogenic stress analysis of superconducting structures in high magnetic fields (open access)

Nickel--chromium strain gages for cryogenic stress analysis of superconducting structures in high magnetic fields

Evaluation and calibration measurements were performed on commercial nickel-chromium metal-foil strain gages in a high-magnetic-field (12 T), liquid-helium (4.2 K) environment. The purpose was to fully characterize strain gages for use at cryogenic temperatures in high magnetic fields. In this study, the magnetoresistance of a number of strain gages was measured in three orthogonal directions at mechanical strain levels to 8900 ..mu..m/m. As a result, a unique calibration curve was defined for magnetoresistance strain errors that is independent of strain level and field direction to 12 T at 4.2 K. A current strain-gage application is the measurement of superconductor mechanical properties. These gages will soon be used in the stress analysis of superconducting fusion magnets during cooldown from ambient temperatures and during operation at 4.2 K with magnetic fields to 12 T.
Date: October 5, 1977
Creator: Freynik, H.S. Jr.; Roach, D.R.; Deis, D.W. & Hirzel, D.G.
Object Type: Article
System: The UNT Digital Library
Ductile-Brittle Transition Temperature testing of tungsten using the three-point bend test (open access)

Ductile-Brittle Transition Temperature testing of tungsten using the three-point bend test

Three-point bend tests were performed to determine the Ductile-Brittle Transition Temperatures (DBTTs) of forged and chemical vapor deposition (CVD) tungsten. Testing was performed under quasi-static conditions at temperatures between 23{degrees}C and 450{degrees}C using a forced-air environmental chamber. Load-displacement data from the three-point bend tests indicated that the constitutive behavior of the materials tested varied considerably. Finite element modeling of the three-point bend test was performed to investigate plastic strains induced in the samples during testing as a function of constitutive behavior. The modeling assumed plane stress conditions in the sample and simple bi-linear elastic-plastic constitutive behavior of the test material. The strains induced in the samples were found to be functions of both the yield stress and work hardening behavior of the materials. The use of the three-point bend test to determine DBTT, and the DBTTs reported for the test materials, are discussed relative to the modeling results. It is concluded that the three-point bend test has some utility in the determination of DBTTs if some caution is used in the selection of test parameters and fixture geometries. However, the three-point bed test does not provide a complete picture of the nature of the ductile-brittle transition. 12 refs., 9 figs.
Date: March 5, 1991
Creator: Lassila, D.H.; Magness, F. & Freeman, D.
Object Type: Report
System: The UNT Digital Library
Improved collecting apparatus (open access)

Improved collecting apparatus

An improved collecting apparatus for small aquatic or airborne organisms such as plankton, larval fish, insects, etc. The improvement constitutes an apertured removal container within which is retained a collecting bag, and which is secured at the apex of a conical collecting net. Such collectors are towed behind a vessel or vehicle with the open end of the conical net facing forward for trapping the aquatic or airborne organisms within the collecting bag, while allowing the water or air to pass through the apertures in the container. The container is readily removable from the collecting net whereby the collecting bag can be quickly removed and replaced for further sample collection. The collecting bag is provided with means for preventing the bag from being pulled into the container by the water or air following therethrough.
Date: March 5, 1981
Creator: Duncan, C.P.
Object Type: Text
System: The UNT Digital Library
Testing of the MFTF magnets (open access)

Testing of the MFTF magnets

This paper describes the cooldown and testing of the first yin-yang magnet for the Mirror Fusion Test Facility. The introduction describes the superconducting magnet; the rest of the paper explains the tests prior to and including magnet cooldown and final acceptance testing. The MFTF (originally MX) was proposed in 1976 and the project was funded for construction start in October 1977. Construction of the first large superconducting magnet set was completed in May 1981 and testing started shortly thereafter. The acceptance test procedures were reviewed in May 1981 and the cooldown and final acceptance test were done by the end of February 1982. During this acceptance testing the magnet achieved its full design current and field.
Date: May 5, 1982
Creator: Kozman, T.A.; Chang, Y. & Dalder, E.N.C.
Object Type: Article
System: The UNT Digital Library
Design of the Target Fabrication Tritium Laboratory (open access)

Design of the Target Fabrication Tritium Laboratory

The design of the Target Fabrication Tritium Laboratory for deuterium-tritium fuel processing for laser fusion targets has been accomplished with the intent of providing redundant safeguard systems. The design of the tritium laboratory is based on a combination of tritium handling techniques that are currently used by experienced laboratories. A description of the laboratory in terms of its interrelated processing systems is presented to provide an understanding of the design features for safe operation.
Date: May 5, 1982
Creator: Sherohman, J. W.; Roberts, D. H. & Levine, B. H.
Object Type: Report
System: The UNT Digital Library
Technology development for high-salinity geothermal resources (open access)

Technology development for high-salinity geothermal resources

An impulse turbine for Total Flow utilization of geothermal fluids was tested. Performance measurements verify the calculational model. The research goal of 70% engine efficiency remains credible. Addition of acid to the brine prevents scaling and precipitation at moderate costs. Corrosion and erosion of turbine materials for the Total Flow Process are not severe. (JB)
Date: August 5, 1977
Creator: Lundberg, A.W.
Object Type: Article
System: The UNT Digital Library
Effect of electrical potential on scale formation in Salton Sea brine (open access)

Effect of electrical potential on scale formation in Salton Sea brine

None
Date: November 5, 1975
Creator: Schock, R. N. & Duba, A.
Object Type: Report
System: The UNT Digital Library
(Fission product transport experiments (HFR-B1)) (open access)

(Fission product transport experiments (HFR-B1))

Travel to the JRC Petten was for the purpose of discussing the HFR-B1 experiment and post irradiation activities. Technical assessment of the experiment strongly supports the concept of enhanced fission gas release at temperatures above 1100{degree}C, the extensive release of stored fission gas at water vapor levels postulated in accident scenarios, an increase in the steady-state fission gas release under hydrolyzing conditions, and an increase in gas release during thermal cycling. Schedules were established for completion of the work and issuance of reports by September 1990. At the KFA Juelich agreement was reached on the PIE activities for HFR-B1 and a schedule established. The final PIE report is due June 1991. Choices of accident condition tests in the PIE have yet to be made by the US participants. A proposal for the establishment of a new cooperative effort on model and code development was presented at the Institut fuer Nukleare Sicherheitsforschung of KFA. The proposal was considered premature; discussions dealing with general principles, basic aims, and organization were requested; particular concerns about free exchange of information, overlap with the existing safety subprogram, and exclusive cooperation with ORNL were raised. A strong desire for cooperation and the opinion that the raised …
Date: December 5, 1989
Creator: Myers, B.F.
Object Type: Report
System: The UNT Digital Library
H-Division quarterly report. October-December 1981 (open access)

H-Division quarterly report. October-December 1981

Progress is reported in the following areas: (1) high pressure structural phase transition in Na, Mg and Al; (2) thermal and compressibility properties of the alkali metals; (3) electrical cnductivity in hydrogen plasmas; (4) plasma pseudopotentials; (5) thermonuclear reaction rates in strongly coupled plasmas; (6) thermodynamic consistency in BQL interpolants; (7) nonequilibrium molecular dynamics of plastic flow; (8) constitutive models in the LLNL hydrodynamic codes; (9) turbulence interaction with thermochemically inert solid particles; (10) the equation of state of molecular hydrogen and deuterium from shock-wave experiments at 760 kbar; and (11) nuclear-explosive-driven equation-of-state experiment. (WHK)
Date: March 5, 1982
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Powerplant Productivity Improvement Study: benefits of improved powerplant reliability. Final report, Project 2, Task 2 (open access)

Powerplant Productivity Improvement Study: benefits of improved powerplant reliability. Final report, Project 2, Task 2

A summary of total cumulative fuel consumption differences by fuel type through 1990 for four improvement scenarios is presented for Commonwealth Edison Company (CE) and for Illinois Power Company (IP). In all scenarios, liquid-fuel consumption is reduced. Generation is shifted to the coal and/or nuclear units for which improved availability has been assumed. For a 2% improvement in both planned (POR) and forced outage rates (FOR), a total of more than 16 million barrels of No. 6 oil will have been saved by 1990 by the two companies. This is the result of improving 10,894 MW on the CE system and 2234 MW on the IP system. For the two utilities combined, gross savings (in 1978 dollars) range from $83 million for a 1% POR improvement to $346 million for 2% improvements in both POR and FOR. In terms of their effect on ratepayers, these savings would be even greater since gross receipt taxes and other charges would be applied to a smaller-generation cost base under the improvement scenarios. Caution must be exercised however, since results do not take into consideration the costs of achieving the improved performance. The proportion of net benefits that would be passed on to ratepayers …
Date: June 5, 1979
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Solar central receiver prototype heliostat. Interim technical progress report (open access)

Solar central receiver prototype heliostat. Interim technical progress report

The objective of Phase I of this project is to support the Solar Central Receiver Power Plant research, development and demonstration effort by: (1) Establishment of a heliostat design, with associated manufacturing, assembly, installation and maintenance approaches, that, in quantity production will yield significant reductions in capital and operating costs over an assumed 30 year plant lifetime as compared with existing designs. (2) Identification of needs for near term and further research and development in heliostat concept, materials, manufacture, installation, maintenance, and other areas, where successful accomplishment and application would offer significant payoffs in the further reduction of the cost of electrical energy from Solar Central Receiver Power Plants. The Phase I study will define a low-cost heliostat preliminary design and the conceptual design of a heliostat manufacturing/installation plan which will result in low life cycle cost when produced and installed at high rate and large quantities for commercial Solar Central Receiver Power Plants. The study will develop the annualized life cycle cost and the performance of heliostats for a 30 year plant life, for each of three rates of continuous production and installation. The three specified rates are 25,000, 250,000, and 1,000,000 heliostats per year. The analysis of these …
Date: April 5, 1978
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Effects of doping on hybridization gapped materials (open access)

Effects of doping on hybridization gapped materials

Doping studies are presented on three materials exhibiting hybridization gaps: Ce{sub 3}Bi{sub 4}Pt{sub 3}, U{sub 3}Sb{sub 4}Pt{sub 3}, and CeRhSb. In the case of trivalent La, Y, or Lu substituting for Ce or U, there is a suppression of the low temperature gap and an increase in the electronic specific heat, {gamma}. In the case of tetravalent Th substitutions for U there is no change in {gamma} and in the case of tetravalent Zr substitution for Ce in CeRhSb, there is an enhanced semiconductor-like behavior in the electrical resistance. These results are discussed in the light of a simple model of hybridization gapped systems. 12 refs., 3 figs.
Date: June 5, 1991
Creator: Canfield, P. C.; Thompson, J. D.; Hundley, M. F.; Lacerda, A. & Fisk, Z.
Object Type: Article
System: The UNT Digital Library