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in subjects: "Velocity"

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Controlled-source electromagnetic survey at Soda Lakes geothermal area, Nevada

The EM-60 system, a large-moment frequency-domain electromagnetic loop prospecting system, was operated in the Soda Lakes geothermal area, Nevada. Thirteen stations were occupied at distances ranging from 0.5-3.0 km from two transmitter sites. These yielded four sounding curves--the normalized amplitudes and phases of the vertical and radial magnetic fields as a function of frequency--at each station. In addition, two polarization ellipse parameters, ellipticity and tilt angle, were calculated … more

Date: July 1, 1980

Creator: Stark, M.; Wilt, M.; Haught, J. R. & Goldstein, N.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Diffusion of Slow Electrons in Gases

The properties of electrons in a gas and an external electric field, e.g., agitation velocity, free path, energy lost per collision, and collision cross sections, were determined for electrons of energy less than 2 ev in a large number of gases. The computations were made from previously measured values for Townsend's energy factor or the ratio of electron agitation energy to molecule thermal energy. Results are presented for hydrogen, nitrogen, carbon dioxide, methane, ethylene, cyclopropane, … more

Date: October 24, 1961

Creator: Forester, D. W. & Cochran, L. W.

Item Type: Thesis or Dissertation

Partner: UNT Libraries Government Documents Department

open access

Analytical model for a vertical buoyant jet

An analytical model for a round and two-dimensional turbulent buoyant jet which is discharged vertically into a stagnant ambient is developed. The buoyant jet is considered to have three separate zone models which are matched to form a complete solution. The velocity field is determined for the entire jet and plume regions by the use of an eddy viscosity which varies along the axis of the jet. The centerline decay of buoyancy is determined throughout and the results are compared to existing num… more

Date: October 1, 1980

Creator: Lee, D. W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

HIVELITE propellant characterization

No Description Available.

Date: March 14, 1975

Creator: Finger, M. & Hayes, B.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Giotto observations of the bow shock at Comet Halley

Preliminary results from the JPA instrument on Giotto indicate that Comet Halley, even on the flanks, has a bow shock which moves backwards and forwards over the spacecraft. To understand the structure properly will require more detailed investigation of the relationships between three particle populations, cometary ions, solar wind ions and electrons.

Date: January 1, 1986

Creator: Formisano, V.; Amata, E.; Wilken, B.; Jockers, K.; Johnstone, A.; Coates, A. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Modeling of coupled geochemical and transport processes: An overview

Early coupled models associated with fluid flow and solute transport have been limited by assumed conditions of constant temperature, fully saturated fluid flow, and constant pore fluid velocity. Developments including coupling of chemical reactions to variable fields of temperature and fluid flow have generated new requirements for experimental data. As the capabilities of coupled models expand, needs are created for experimental data to be used for both input and validation. 25 refs.

Date: October 1, 1989

Creator: Carnahan, C.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Optimization of a VISAR for measuring flyer-plate velocities

VISAR (Velocity Interferometer System for Any Reflector) is commonly used for measuring flyer-plate velocities up to 6 km/s. Flyer plates can travel as much as 1 mm, which is large compared to usual depth-of-focus requirements for VISARs. Flyer plates are explosively driven, or driven by some other very energetic means; as such, they must be tested in a chamber, which will contain the explosion. Routing the laser beam to the chamber and the signal beam to the VISAR can be done safely and easily… more

Date: May 6, 1992

Creator: Sweatt, W. C.; Crump, O. B., Jr. & Brigham, W. P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Particulate behavior in a controlled-profile pulverized coal-fired reactor: A study of coupled turbulent particle dispersion and thermal radiation transport

This report describes recent progress in a fundamental, three-year investigation of the coupled problem of turbulent particle dispersion and thermal radiation transport. The project's objective is to make measurements of particle size, velocity, number density, temperature and wall radiant heat flux in a parametrically-controlled reactor presently existent at Brigham Young University (BYU). Although the study proposed here is primarily designed to provide experimental data not currently availab… more

Date: January 1, 1992

Creator: Queiroz, M. & Webb, B.W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Detection of structural degradation

A time domain method developed for determining dynamic system characteristics is applied to structural monitoring and/or flaw detection. The potential usefulness for monitoring is evaluated based on several criteria, which include sensitivity to structural changes, location of flaws, and dependence upon excitation signals. The strengths and weaknesses of the methods are discussed. Also, structural monitoring using a signal's singular values is presented and evaluated. 2 refs., 4 figs., 2 tabs.

Date: January 1, 1991

Creator: Endebrock, E.G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Some atmospheric tracer experiments in complex terrain at LASL: experimental design and data. [Fluorescent particle tracer study]

Two series of atmospheric tracer experiments were conducted in complex terrain situations in and around the Los Alamos Scientific Laboratory. Fluorescent particle tracers were used to investigate nighttime drainage flow in Los Alamos Canyon and daytime flow across the local canyon-mesa complex. This report describes the details of these experiments and presents a summary of the data collected. A subsequent report will discuss the analysis of these data.

Date: March 1, 1978

Creator: Archuleta, J.; Barr, S.; Clements, W.E.; Gedayloo, T. & Wilson, S.K.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Development of a three-dimensional model of the atmospheric boundary layer using the finite element method

This report summarizes our current effort and ideas toward the development of a model for the planetary boundary layer using the finite element technique. As an initial step, the finite element methodology is applied to simpler version of the boundary layer equations given by the two-dimensional, constant-property, incompressible conservation equations (Navier-Stokes equations). Solution procedures for both the steady-state and transient equations are discussed. For the transient problem, a var… more

Date: November 22, 1977

Creator: Lee, R. L. & Gresho, P. M.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Freely expanding detonation products: Scaling of rate processes

Using the Los Alamos reactive hydrodynamics code KIVA, calculations have been made to simulate the free expansion of cylinders of detonation products into a high vacuum. The emphasis of this paper is on the scaling of rate processes with cylinder size and initial conditions as a function of position in the expanding mass. The processes considered include diffusion, unimolecular decomposition, biomolecular radical reactions, and vibrational relaxation. The calculations also give time-dependent v… more

Date: January 1, 1988

Creator: Greiner, N. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Development and utilization of new diagnostics for dense-phase pneumatic transport

Dense-phase pneumatic transport is an attractive means of conveying solids. Unfortunately, because of the high solid concentrations, this transport method is a difficult regime in which to carry out detailed measurements. Hence most details of the flow are unknown. In this context, the main objective of this work is to develop probes for local measurements of solid velocity and holdup in dense gas-solid flows. Because we anticipate the recent theories of rapid granular flows will bring insight … more

Date: January 1, 1991

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Pellet fueling development at ORNL

Advanced plasma fueling systems for magnetic confinement devices are being developed at the Oak Ridge National Laboratory (ORNL). The general approach is that of producing and accelerating frozen hydrogenic pellets at speeds in the range of 1-2 km/s and higher. Two specific concepts are under development: (1) high-speed pneumatic acceleration; and (2) mechanical (centrifugal) acceleration. Both approaches are being pursued to meet the projected pellet size and delivery rates for major near-term… more

Date: September 1, 1986

Creator: Combs, S. K.; Milora, S. L.; Foster, C. A.; Schuresko, D. D.; Foust, C. R.; Simmons, D. W. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Computational determination of ballistic limits for a simple Whipple bumper shield

A series of numerical simulations has been performed using the multi-dimensional hydrodynamics code CTH to computationally determine a ballistic limit for a Whipple bumper shield. The ballistic limit is generally characterized as a critical diameter such that particle diameters greater than the ballistic limit will generate debris clouds that will penetrate the rear wall and particle diameters less than the ballistic limit will not. The particular shield design used for these analyses is define… more

Date: January 1, 1991

Creator: Hertel, E.S.; Chhabildas, L.C.; Yarrington, L. (Sandia National Labs., Albuquerque, NM (United States)) & Hill, S.A. (National Aeronautics and Space Administration, Huntsville, AL (United States). George C. Marshall Space Flight Center)

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Electron cyclotron heating in tokamaks

Tokamaks may be efficiently heated at electron cyclotron resonance by launching of the extraordinary wave from the inside of the torus with a simple waveguide aperture. For typical tokamak parameters, 90% of the incident energy is absorbed in one traversal of the resonant surface. There is an effective maximum density for linear heating at the point where the plasma frequency is equal to the cyclotron frequency. The bulk of the plasma electrons is heated, increasing the perpendicular energy wit… more

Date: November 1, 1977

Creator: Eldridge, O.; Namkung, W. & England, A. C.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

A source of observational constraints on the structure of Wolf-Rayet winds

In some WR + O-star binary systems the WR wind eclipses the O star. The profile changes as function of impact are reproduced with a simple model which gives information on both the radial dependence of the velocity and opacity. 2 refs.

Date: January 1, 1989

Creator: Auer, L.H.; Koenigsberger, G. (Los Alamos National Lab., NM (USA) & Universidad Nacional Autonoma de Mexico, Mexico City (Mexico). Inst. de Astronomia)

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Simulation of winds as seen by a rotating vertical axis wind turbine blade

The objective of this report is to provide turbulent wind analyses relevant to the design and testing of Vertical Axis Wind Turbines (VAWT). A technique was developed for utilizing high-speed turbulence wind data from a line of seven anemometers at a single level to simulate the wind seen by a rotating VAWT blade. Twelve data cases, representing a range of wind speeds and stability classes, were selected from the large volume of data available from the Clayton, New Mexico, Vertical Plane Array … more

Date: February 1, 1984

Creator: George, R.L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Hypervelocity launch capabilities to over 10 km/s

Very high pressure and acceleration is necessary to launch flier plates to hypervelocities. In addition, the high pressure loading must be uniform, structured, and shockless, i.e., time-dependent to prevent the flier plate from either fracturing or melting. In this paper, a novel technique is described which allows the use of megabar level loading pressures, and 10{sup 9} g acceleration to launch intact flier plates to velocities of 12.2 km/s. 32 refs., 2 figs.

Date: January 1, 1991

Creator: Chhabildas, L.C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Mechanisms affecting mass transfer in fuel cells

An initial analysis of particulate effects on molten carbonate fuel cells has been conducted. The analysis has been applied to a conceptual fuel cell with operating parameters appropriate to use with future power generation plants. Particle transport due to several mechanisms has been considered and dominant mechanisms affecting particle delivery to anode channel surfaces and into anode pores have been identified. Thermophoresis and gas flow out from anode pores have been found to inhibit parti… more

Date: March 15, 1982

Creator: Wenglarz, R.A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Smoothly waning, symmetrically expanding, cavity-pressure loads in earth materials

An approximate solution for the pressure loading required to expand a spherical cavity in rock and soil targets is derived. A dual characterization of fracture and flow material model is used. Frictional resistance to flow is also included. Non-linear volumetric strain hardening is modeled with bi-linear curves and unloading is assumed to be non-dilative. Applications of this solution form to the prediction of pressure loading on slender, convex-nosed earth penetrators and on spherically-nosed … more

Date: January 1, 1982

Creator: Priddy, T.G.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Analytical and experimental studies of heat pipe radiation cooling of hypersonic propulsion systems

Preliminary, research-oriented, analytical and experimental studies were completed to assess the feasibility of using high-temperature heat pipes to cool hypersonic engine components. This new approach involves using heat pipes to transport heat away from the combustor, nozzle, or inlet regions, and to reject it to the environment by thermal radiation from an external heat pipe nacelle. For propulsion systems using heat pipe radiation cooling (HPRC), it is possible to continue to use hydrocarbo… more

Date: January 1, 1992

Creator: Martin, R.A.; Merrigan, M.A.; Elder, M.G.; Sena, J.T.; Keddy, E.S. (Los Alamos National Lab., NM (United States)) & Silverstein, C.C. (CCS Associates, Bethel Park, PA (United States))

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Velocity distribution of laser photoionized neutrals ejected from methanol-dosed aluminium(111) by electron-stimulated desorption

Nonresonant multiphoton ionization at 193 nm wavelength was employed for efficient detection of electron-stimulated neutral desorption from Al(111) dosed with methanol to produce monolayer methoxide coverage. Velocity spectra were measured by the flight time from the crystal surface to the focal region of the laser beam with a pulsed primary electron beam of 3 keV and the sample at 300 K. Either the C{sup +} or HCO{sup +} photofragment indicated the same non-Boltzmann velocity spectrum for the … more

Date: January 1, 1989

Creator: Young, C. E.; Whitten, J. E.; Pellin, M. J.; Gruen, D. M.; Jones, P. L. (Argonne National Lab., IL (USA) & Ohio State Univ., Columbus, OH (USA). Dept. of Chemistry)

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Application of ultrasonic waves to assess grain structure in cast stainless steel

Although the ASME code requires the inspection of cast stainless steel (CSS) piping in nuclear reactors, it has not been possible to demonstrate unambiguously that current inspection techniques are adequate. Ultrasonic inspection is difficult because the microstructure of CSS can vary considerably, from elastically isotropic with equiaxed, relatively small grains to elastically anisotropic with a columnar grain structure to a combination of the two. For the near term, improvements that may incr… more

Date: April 1, 1985

Creator: Kupperman, D.S.; Reimann, K.J. & Abrego-Lopez, J.

Item Type: Article

Partner: UNT Libraries Government Documents Department