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Exploiting the power of DSM and SMP clusters for parallel CFD (open access)

Exploiting the power of DSM and SMP clusters for parallel CFD

The new generation of powerful DSM and SMP cluster computers enables simulations of fluid dynamics at sufficient resolution to compute the complex nonlinear interactions of small-scale turbulent motions with a large-scale driving flow. With a new programming model of hierarchical shared memory multitasking, it is possible to exploit these new systems without disrupting the flow of small and medium-sized jobs that makes their existence possible.
Date: March 15, 1999
Creator: Anderson, S. E.; Cohen, R. H.; Curtis, B. C.; Dannevik, W. P.; Dimits, A. M.; Dinge, D. et al.
Object Type: Article
System: The UNT Digital Library
Early Inflation and Cosmology in Theories with Sub-Millimeter Dimensions (open access)

Early Inflation and Cosmology in Theories with Sub-Millimeter Dimensions

We discuss early cosmology in theories where the fundamental Planck mass is close to the TeV scale. In such theories the standard model fields are localized to a (3 + 1)-dimensional wall with n new transverse sub-millimeter sized spatial dimensions. The topics touched upon include: early inflation that occurs while the size of the new dimensions are still small, the spectrum and magnitude of density perturbations, the post-inflation era of contraction of our world while the internal dimensions evolve to their final ''large'' radius, and the production of gravitons in the bulk during these two eras. The radion moduli problem is also discussed.
Date: March 15, 1999
Creator: Arkani-Hamed, Nima
Object Type: Report
System: The UNT Digital Library
Rapid asymmetric inflation and early cosmology in theories with sub-millimeter dimensions (open access)

Rapid asymmetric inflation and early cosmology in theories with sub-millimeter dimensions

It was recently pointed out that the fundamental Planck mass could be close to the TeV scale with the observed weakness of gravity at long distances being due the existence of new sub-millimeter spatial dimensions. In this picture the standard model fields are localized to a (3+1)-dimensional wall or ''3-brane''. We show that in such theories there exist attractive models of inflation that occur while the size of the new dimensions are still small. We show that it is easy to produce the required number of efoldings, and further that the density perturbations {delta}{rho}/{rho} as measured by COBE can be easily reproduced, both in overall magnitude and in their approximately scale-invariant spectrum. In the minimal approach, the inflaton field is just the moduli describing the size of the internal dimensions, the role of the inflationary potential being played by the stabilizing potential of the internal space. We show that under quite general conditions, the inflationary era is followed by an epoch of contraction of our world on the brane, while the internal dimensions slowly expand to their stabilization radius. We find a set of exact solutions which describe this behavior, generalizing the well-known Kasner solutions. During this phase, the production …
Date: March 15, 1999
Creator: Arkani-Hamed, Nima
Object Type: Report
System: The UNT Digital Library
The FEL development at the Advanced Photon Source. (open access)

The FEL development at the Advanced Photon Source.

Construction of a single-pass free-electron laser (FEL) based on the self-amplified spontaneous emission (SASE) mode of operation is nearing completion at the Advanced Photon Source (APS) with initial experiments imminent. The APS SASE FEL is a proof-of-principle fourth-generation light source. As of January 1999 the undulator hall, end-station building, necessary transfer lines, electron and optical diagnostics, injectors, and initial undulatory have been constructed and, with the exception of the undulatory, installed. All preliminary code development and simulations have also been completed. The undulator hall is now ready to accept first beam for characterization of the output radiation. It is the project goal to push towards fill FEL saturation, initially in the visible, but ultimately to W and VUV, wavelengths.
Date: March 15, 1999
Creator: Arnold, N. D.; Benson, C.; Berg, S.; Berg, W.; Biedron, S. G.; Chae, Y. C. et al.
Object Type: Article
System: The UNT Digital Library
Dehumidification: Prediction of Condensate Flow Rate for Plate-Fin Tube Heat Exchangers Using the Latent j Factor (open access)

Dehumidification: Prediction of Condensate Flow Rate for Plate-Fin Tube Heat Exchangers Using the Latent j Factor

Condensate flow rate is an important factor in designing dehumidifiers or evaporators. In this paper, the latentj fimtor is used to analyze the dehumidification performance of two plate-fin tube heat exchangers. This latent j factor, analogous to the total j factor, is a flmction of the mass transfa coefllcient, the volumetric air flow rate, and the Schmidt number. This latent j factor did predict condensate flow rate more directly and accurately than any other sensiblej factor method. The Iatentj factor has been used in the present study because the sensible j factor correlations presented in the literature failed to predict the condensate flow rate at high Reynolds numbers. Results show that the latent j i%ctor em be simply correlated as a fhnction of the Reynolds number based on the tube outside diameter and number of rows of the heat exchanger.
Date: March 15, 1999
Creator: Baxter, V. D.; Chen, D. T. & Conklin, J. C.
Object Type: Article
System: The UNT Digital Library
Influence of Surface Material on the BCl Density in Inductively Coupled Discharges (open access)

Influence of Surface Material on the BCl Density in Inductively Coupled Discharges

The relative density of BCl radicals has been measured in a modified Applied Materials DPS metal etch chamber using laser-induced fluorescence. In plasmas containing mixtures of BCl{sub 3} with Cl{sub 2}, Ar and/or N{sub 2}, the relative BCl density was measured as a function of source and bias power, pressure, flow rate, BCl{sub 3}/Cl{sub 2} ratio and argon addition. To determine the influence of surface materials on the bulk plasma properties, the relative BCl density was measured using four different substrate types; aluminum, alumina, photoresist, and photoresist-patterned aluminum. In most cases, the relative BCl density was highest above photoresist-coated wafers and lowest above blanket aluminum wafers. The BCl density increased with increasing source power and the ratio of BCl{sub 3} to Cl{sub 2}, while the addition of N{sub 2} to a BCl{sub 3}/Cl{sub 2} plasma resulted in a decrease in BCl density. The BCl density was relatively insensitive to changes in the other plasma parameters.
Date: March 15, 1999
Creator: Blain, M.G.; Hamilton, T.W. & Hebner, G.A.
Object Type: Article
System: The UNT Digital Library
Risk-Dominant Scenarios from Several SRS Facilities (open access)

Risk-Dominant Scenarios from Several SRS Facilities

This report and associated spreadsheets describe the SRS safety analysis provided for four selected transuranic storage and stabilization facilities. For each of the four sets of analysis, the bounding events in each frequency category are identified, key inputs and assumptions are stated, and final doses tabulated.
Date: March 15, 1999
Creator: Blanchard, A.
Object Type: Report
System: The UNT Digital Library
Perry Daily Journal (Perry, Okla.), Vol. 106, No. 51, Ed. 1 Monday, March 15, 1999 (open access)

Perry Daily Journal (Perry, Okla.), Vol. 106, No. 51, Ed. 1 Monday, March 15, 1999

Daily newspaper from Perry, Oklahoma that includes local, state, and national news along with advertising.
Date: March 15, 1999
Creator: Brown, Gloria
Object Type: Newspaper
System: The Gateway to Oklahoma History
The Express-Star (Chickasha, Okla.), Ed. 1 Monday, March 15, 1999 (open access)

The Express-Star (Chickasha, Okla.), Ed. 1 Monday, March 15, 1999

Daily newspaper from Chickasha, Oklahoma that includes local, state, and national news along with advertising.
Date: March 15, 1999
Creator: Bush, Kent
Object Type: Newspaper
System: The Gateway to Oklahoma History
Characterization of Off Gas Flow Surges in the DWPF Melter (open access)

Characterization of Off Gas Flow Surges in the DWPF Melter

The Defense Waste Processing Facility (DWPF) is currently producing radioactive canisters containing vitrified high-level waste. A slurry of high-level waste and glass frit is fed into a joule-heated melter where the mixture is dried, calcined, and melted. The off gases produced are treated in an off gas system designed to remove radioactive particulate and volatile components before exhausting clean gases to the environment. Surges in the flow of off gas can occur by various means, and must be accommodated by the melter off gas system. A method for calculating the magnitude of off gas surges is presented and applied to actual plant data. The melter off gas control system is shown to mitigate the effects of most flow surges without significant impact to plant operations.
Date: March 15, 1999
Creator: Calloway, T.B. Jr.
Object Type: Article
System: The UNT Digital Library
Probing excited states in nuclei at and beyond the proton dripline. (open access)

Probing excited states in nuclei at and beyond the proton dripline.

The coupling of a Compton-suppressed Ge (CSGe) detector array to a recoil separator has seen limited use in the past due to the low efficiency for measuring recoil--{gamma} ray coincidences (< 0.1%). With the building of new generation recoil separators and gamma-ray arrays, a substantial increase in detection efficiency has been achieved. This allows for the opportunity to measure excited states in nuclei with cross-sections below 100 nb. In this paper, results from the coupling of a modest array of CSGe detectors (AYE-Ball) and a current generation Ge array (Gammasphere) with a recoil separator (FMA) will be presented.
Date: March 15, 1999
Creator: Carpenter, M. P.
Object Type: Article
System: The UNT Digital Library
Vector Potential and Stored Energy of a Quadrupole Magnet Array (open access)

Vector Potential and Stored Energy of a Quadrupole Magnet Array

The vector potential, magnetic field and stored energy of a quadrupole magnet array are derived. Each magnet within the array is a current sheet with a current density proportional to the azimuthal angle 2{theta} and the longitudinal periodicity (2m-1){pi}/L. Individual quadrupoles within the array are oriented in a way that maximizes the field gradient The array does not have to be of equal spacing and can be of a finite size, however when the array is equally spaced and is of infinite size the solution can be simplified. We note that whereas, in a single quadrupole magnet with a current density proportional to cos2{theta} the gradient is pure, such purity is not preserved in a quadrupole array.
Date: March 15, 1999
Creator: Caspi, S.
Object Type: Article
System: The UNT Digital Library
The Effect of Circuiting Arrangement on the Thermal Performance of Refrigeration Mixtures in Tube-and-Fin Condensing Heat Exchangers (open access)

The Effect of Circuiting Arrangement on the Thermal Performance of Refrigeration Mixtures in Tube-and-Fin Condensing Heat Exchangers

For the pure or azeotropic refrigerants typically used in present air conditioning and refrigeration applications, the refrigerant changes phase at a constant temperature. Thus, the refrigerant circuiting arrangement such as crossfiow, counterfiow, or cross-counterflow, has no effect on the thermal performance. For zeotropic refrigerant mixtures, however, the phase-change occurs over a temperature range, or "glide", and the refrigerant circuiting arrangement, or flow path through the heat exchanger, can affect the thermal performance of both the heat exchangers as well as the overall efficiency of the vapor compression cooling cycle. The effects of tsvo diflerent circuiting arrangements on the thermal performance of a zeotropic retligerant mixture and an almost azeotropic refrigerant mixture in a four-row cross-countertlow heat exchanger arrangement are reported here. The two condensers differ only in the manner of circuiting the refrigerant tubes, where one has refrigerant always flowing downward in the active heat transfer region ("identical order") and the other has refrigerant alternating flow direction in the active heat transfer region ("inverted order"). All other geometric parameters, such as bce are% fin louver geometry, refrigerant tube size and enhancement etc., are the same for both heat exchangers. One refrigerant mixture (R-41OA) un&rgoes a small temperature change ("low glide") …
Date: March 15, 1999
Creator: Chen, D. T. & Conklin, J. C.
Object Type: Article
System: The UNT Digital Library
The Feasibility of Monitoring Continuous Wave Sources with Seismic Arrays (open access)

The Feasibility of Monitoring Continuous Wave Sources with Seismic Arrays

This paper identifies and explores the technical requirements and issues associated with remotely monitoring continuous wave (CW) sources with seismic arrays. Potential approaches to this monitoring problem will be suggested and partially evaluated to expose the monitoring challenges which arise when realistic local geologies and cultural noise sources are considered. The selective directionality and the adaptive noise cancellation properties of arrays are required to observe weak signals while suppressing a colored background punctuated with an unknown distribution of point and sometimes distributive sources. The array is also required to characterize the emitters and propagation environment so as to properly focus on the CW sources of interest while suppressing the remaining emitters. The proper application of arrays requires an appreciation of the complexity of propagation in a non-homogeneous earth. The heterogeneity often limits the available spatial coherence and therefore the size of the army. This adversely impacts the array gain and the array's ability to carefully resolve various emitters. Arrays must also contend with multipath induced by the source and the heterogeneous earth. If the array is to focus on an emitter and realize an enhancement in the signal to noise ratio, methods must be sought to coherently add the desired …
Date: March 15, 1999
Creator: Claassen, J.P.; Elbring, G. & Ladd, M.
Object Type: Article
System: The UNT Digital Library
Altus Times (Altus, Okla.), Vol. 100, No. 1, Ed. 1 Monday, March 15, 1999 (open access)

Altus Times (Altus, Okla.), Vol. 100, No. 1, Ed. 1 Monday, March 15, 1999

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: March 15, 1999
Creator: Cole, Carol
Object Type: Newspaper
System: The Gateway to Oklahoma History
Congregation Beth Israel Bulletin, Volume 145, Number 15, March 1999 (open access)

Congregation Beth Israel Bulletin, Volume 145, Number 15, March 1999

Newsletter of Congregation Beth Israel in Houston, including news and events, upcoming services, member announcements, editorials, and other information of interest to congregants.
Date: March 15, 1999
Creator: Congregation Beth Israel (Houston, Tex.)
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Copper Catalyzed Sodium Tetraphenylborate, Triphenylborane, Diphenylborinic Acid and Phenylboronic Acid Decomposition Kinetic Studies in Aqueous Alkaline Solutions (open access)

Copper Catalyzed Sodium Tetraphenylborate, Triphenylborane, Diphenylborinic Acid and Phenylboronic Acid Decomposition Kinetic Studies in Aqueous Alkaline Solutions

This work studied the kinetics of copper-catalyzed decomposition of tetraphenylborate, triphenylborane, diphenylborinic acid and phenylboronic acid (NaTPB, 3PB, 2PB and 1PB, respectively) in aqueous alkaline solution over the temperature range of 25 to 70 degrees C. The statistically designed test matrices added copper sulfate to maximum concentrations of 10 mg/L. The relative rates of decomposition increase in the order of NaTPB < 1PB {tilde} 3PB < 2PB. Dependence of decomposition on the amount of added copper increases in the order of 3PB {tilde} 2PB < 1PB {tilde} NaTPB. Activation energies ranged from 82 to 143 kJ/mole over the temperature range studied. Final decomposition products predominately involved benzene and phenol. All 3PB, 2PB and 1PB intermediate phenylborate species proved relatively stable (< 8 percent decomposition over {tilde} 500 h) towards thermal hydrolysis in 1.5 M NaOH when contained in carbon-steel vessels sealed under air at ambient temperature (23 - 25 degrees C) with no added copper. Measurable (> 10-7 Mh-1) thermal hydrolysis of the phenylborate species occurs at 55 to 70 degrees C in alkaline (0.6-2.3 M OH-, 2-4.7 M Na+) solution with no added copper. The experiments suggest an important role for oxygen in copper-catalyzed phenylborate decomposition. NaTPB decomposes promptly …
Date: March 15, 1999
Creator: Crawford, C.L.
Object Type: Article
System: The UNT Digital Library
Recent applications of bandpass filtering (open access)

Recent applications of bandpass filtering

Bandpass filtering has been applied recently in two widely different seismic applications: S.R. Taylor and A.A. Velasco in their source-path amplitude-correction (SPAC) algorithm and N.K. Yacoub in his maximum spectral energy algorithm for picking teleseismic P-wave arrival times. Though the displacement spectrum is the intermediate product in both cases, the filters and scaling corrections used to estimate it are entirely different. They tested both and found that the scaling used by Taylor and Velasco worked in all cases tested whereas Yacoub's did not. They also found that bandpass filtering as implemented by Taylor and Velasco does not work satisfactorily; however, the Gaussian filter used by Yacoub does work. The bandpass filter of Taylor and Velasco works satisfactorily when the results are centered in the band; however, a comb filter with the same number of poles and zeros as the bandpass used by Taylor and Velasco works better than the bandpass filter.
Date: March 15, 1999
Creator: Denny, M D
Object Type: Report
System: The UNT Digital Library
The Baytown Sun (Baytown, Tex.), Vol. 77, No. 116, Ed. 1 Monday, March 15, 1999 (open access)

The Baytown Sun (Baytown, Tex.), Vol. 77, No. 116, Ed. 1 Monday, March 15, 1999

Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.
Date: March 15, 1999
Creator: Dobbs, Gary
Object Type: Newspaper
System: The Portal to Texas History
Ecological Screening Values for Surface Water, Sediment, and Soil (open access)

Ecological Screening Values for Surface Water, Sediment, and Soil

This document provides a comprehensive listing of ecological screening values for surface water, sediment, and soil.
Date: March 15, 1999
Creator: Friday, G. P.
Object Type: Report
System: The UNT Digital Library
Final Report: Letter to Mr. Kim Abbott, DOE-OAK Cal/EPA-UC Berkeley Bioremediation Reference Laboratory, Report, September 15, 1996 - November 1, 1998 (open access)

Final Report: Letter to Mr. Kim Abbott, DOE-OAK Cal/EPA-UC Berkeley Bioremediation Reference Laboratory, Report, September 15, 1996 - November 1, 1998

Letter-format report to Project Officer summarizing information on the establishment at the University of California Berkeley campus of a Bioremediation Reference Laboratory to provide independent reference services and testing as needed to assist the California Environmental Protection Agency in the evaluation of bioremediation technologies submitted for the certification/ verification of performance claims under California statute. The project resulted in the establishment of a technical capability not otherwise available to the Agency.
Date: March 15, 1999
Creator: Fuhs, G. Wolfgang
Object Type: Report
System: The UNT Digital Library
Child Care Subsidies: Federal Grants and Tax Benefits for Working Families (open access)

Child Care Subsidies: Federal Grants and Tax Benefits for Working Families

This report examines the subsidies that families might receive under the Child Care and Development Fund(CCDF) and the Dependent care tax credit(DCTC) and the subsequent out-of-pocket costs they might bear, depending on their income and the state in which they live.
Date: March 15, 1999
Creator: Gabe, Thomas; Lyke, Bob & Spar, Karen
Object Type: Report
System: The UNT Digital Library
The Application of Spatial Signature Analysis to Electrical Test Data: Validation Study (open access)

The Application of Spatial Signature Analysis to Electrical Test Data: Validation Study

This paper presents the results of the Spatial Signature Analysis (SSA) Electrical-test (e-test) validation study that was conducted between February and June, 1998. SSA is an automated procedure developed by researchers at the Oak Ridge National Laboratory to address the issue of intelligent data reduction while providing feedback on current manufacturing processes. SSA was initially developed to automate the analysis of optical defect data. Optical defects can form groups, or clusters, which may have a distinct shape. These patterns can reveal information about the manufacturing process. Optical defect SSA uses image processing algorithms and a classifier system to interpret and identify these patterns, or signatures. SSA has been extended to analyze and interpret electrical test data. The algorithms used for optical defect SSA have been adapted and applied to e-test binmaps. An image of the binmap is created, and features such as geometric and invariant moments are extracted and presented to a pair-wise, fuzzy, k-NN classifier. The classifier itself was prepared by manually training, which consists of storing example signatures of interest in a library, then executing an automated process which treats the examples as prototype signatures. The training process includes a procedure for automatically determining which features are most …
Date: March 15, 1999
Creator: Gleason, S.S.; Karnowski, T.P.; Lakhani, F. & Tobin, K.W.
Object Type: Article
System: The UNT Digital Library
Physics of collisionless scrape-off-layer plasma during normal and off-normal Tokamak operating conditions. (open access)

Physics of collisionless scrape-off-layer plasma during normal and off-normal Tokamak operating conditions.

The structure of a collisionless scrape-off-layer (SOL) plasma in tokamak reactors is being studied to define the electron distribution function and the corresponding sheath potential between the divertor plate and the edge plasma. The collisionless model is shown to be valid during the thermal phase of a plasma disruption, as well as during the newly desired low-recycling normal phase of operation with low-density, high-temperature, edge plasma conditions. An analytical solution is developed by solving the Fokker-Planck equation for electron distribution and balance in the SOL. The solution is in good agreement with numerical studies using Monte-Carlo methods. The analytical solutions provide an insight to the role of different physical and geometrical processes in a collisionless SOL during disruptions and during the enhanced phase of normal operation over a wide range of parameters.
Date: March 15, 1999
Creator: Hassanein, A. & Konkashbaev, I.
Object Type: Report
System: The UNT Digital Library