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High-flux first-wall design for a small reversed-field pinch reactor

Description: To achieve the goal of a commercially economical fusion power reactor, small physical size and high power density should be combined with simplicity (minimized use of high-technology systems). The Reversed-Field Pinch (RFP) is a magnetic confinement device that promises to meet these requirements with power densities comparable to those in existing fission power plants. To establish feasibility of such an RFP reactor, a practical design for a first wall capable of withstanding high levels of cy… more
Date: January 1, 1982
Creator: Cort, G. E.; Graham, A. L. & Christensen, K. E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Comparison of methods for solving nonlinear finite-element equations in heat transfer

Description: We have derived two new techniques for solving the finite-element heat-transfer equations with highly nonlinear boundary conditions and material properties. When compared with the more commonly employed successive substitution and Newton-Raphson procedures, the new methods speed convergence rates and simultaneously increase the radius of convergence. We have observed reductions in computation time in excess of 80% when the new techniques are employed. The first method accelerates the standard N… more
Date: January 1, 1981
Creator: Cort, G. E.; Graham, A. L. & Johnson, N. L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Microstructure and momentum transport in concentrated suspensions

Description: This paper reviews several coupled theoretical and experimental investigations of the effect of microstructure on momentum transport in concentrated suspensions. An expression to predict the apparent suspension viscosity of mixtures of rods and spheres is developed and verified with falling-ball viscometry experiments. The effects of suspension-scale slip (relative to the bulk continuum) are studied with a sensitive spinning-ball rheometer, and the results are explained with a novel theoretical… more
Date: June 1996
Creator: Mondy, L. A.; Graham, A. L. & Brenner, H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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An inverse problem by boundary element method

Description: Boundary Element Methods (BEM) have been established as useful and powerful tools in a wide range of engineering applications, e.g. Brebbia et al. In this paper, we report a particular three dimensional implementation of a direct boundary integral equation (BIE) formulation and its application to numerical simulations of practical polymer processing operations. In particular, we will focus on the application of the present boundary element technology to simulate an inverse problem in plastics p… more
Date: February 1, 1996
Creator: Tran-Cong, T.; Nguyen-Thien, T. & Graham, A. L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Anisotropic fiber alignment in composite structures

Description: High strength material composite structures are formed with oriented fibers to provide controlled anisotropic fibers. Fibers suspended in non-dilute concentrations (e.g., up to 20 volume percent for fibers having an aspect ratio of 20) in a selected medium are oriented by moving an axially spaced array of elements in the direction of desired fiber alignment. The array elements are generally perpendicular to the desired orientation. The suspension medium may also include sphere-like particles wh… more
Date: December 31, 1992
Creator: Graham, A. L.; Mondy, L. A. & Guell, D. C.
Item Type: Refine your search to only Patent
Partner: UNT Libraries Government Documents Department
open access

Viscosity of concentrated suspensions of sphere/rod mixtures

Description: This paper discusses the viscosity of concentrated suspensions of sphere/rod mixtures by adopting the Thomas relations for spheres and Milliken`s for randomly oriented rods with aspect ratio of 20. The relative viscosity of a mixed suspension may now be calculated for any combination of rods (of aspect ratio 20) and spheres.
Date: May 1, 1996
Creator: Mor, R.; Gottlieb, M.; Graham, A. L. & Mondy, L. A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Aligned, short-fiber composites by novel flow processing methods

Description: A hydrodynamic method has been employed to align short, reinforcing fibers in polymer matrix composite materials. Samples of composite materials were prepared and tested two at a time (one with randomly oriented fibers and the other with aligned fibers) to isolate and directly measure the effect on mechanical properties of aligning the fibers. Data were collected for the ultimate tensile strength, modulus of elasticity, and ultimate tensile strain of the composite samples prepared. Results show… more
Date: January 1, 1993
Creator: Guell, D. C.; Graham, A. L.; Papathanasiou, T. & Petrovic, J. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Finite-element approach to analyzing coupled thermal-hydraulic problems

Description: The finite-element method is used to study thermal-hydraulic systems to determine the pressures and temperatures necessary to obtain an engineering description of a convecting fluid. The fluid-motion formulation utilizes nonlinear flow-resistance coefficients based on experimentally determined relationships associating the hydraulic gradient and velocity field for steady flows. The code developed may also be used in a noncoupled mode to perform either transient thermal analysis or steady lamina… more
Date: January 1, 1983
Creator: Bennett, J. G.; Girrens, S. P.; Cort, G. E.; Graham, A. L. & Johnson, N. L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Aligned, short-fiber composites by novel flow processing methods

Description: A hydrodynamic method has been employed to align short, reinforcing fibers in polymer matrix composite materials. Samples of composite materials were prepared and tested two at a time (one with randomly oriented fibers and the other with aligned fibers) to isolate and directly measure the effect on mechanical properties of aligning the fibers. Data were collected for the ultimate tensile strength, modulus of elasticity, and ultimate tensile strain of the composite samples prepared. Results show… more
Date: March 1, 1993
Creator: Guell, D. C.; Graham, A. L.; Papathanasiou, T. & Petrovic, J. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Hydrodynamic particle migration in small-amplitude, oscillatory, circular couette flow: The limits of reversibility

Description: Initially well-mixed suspensions of large spherical particles in viscous Newtonian fluids subjected to continuous nonhomogeneous shear flows demix and establish large concentration gradients. A number of experimental studies have determined that the particles migrate to the low shear-rate region in one-dimensional flow fields. Other investigators have proposed mechanisms to model the migration caused by the presence of nonuniform shear gradients. Here, we report on the shear-induced migration o… more
Date: March 1, 1992
Creator: Brenner, H.; Altobelli, S. A.; Graham, A. L.; Abbott, J. R. & Monday, L. A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Particle interations in concentrated suspensions

Description: An overview is presented of research that focuses on slow flows of suspensions in which colloidal and inertial effects are negligibly small. We describe nuclear magnetic resonance imaging experiments to quantitatively measure particle migration occurring in concentrated suspensions undergoing a flow with a nonuniform shear rate. These experiments address the issue of how the flow field affects the microstructure of suspensions. In order to understand the local viscosity in a suspension with suc… more
Date: June 1, 1993
Creator: Mondy, L. A.; Graham, A. L.; Abbott, J. R. & Brenner, H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Rheological characterization of nuclear waste using falling-ball rheometry

Description: Knowledge of the rheological properties of saturated solutions containing solid particles is very important in nuclear waste management technology. For example, the nuclear waste in the Hanford Site high-level radioactive waste tanks contains strong electrolyte solutions with a high concentration of solids. Previous attempt using rotational viscometers to determine the rheology has shown unusual thixotropic and shear thinning behaviors with a lack of reproducibility. Using falling-ball rheometr… more
Date: July 1, 1994
Creator: Abbott, J. R.; Unal, C.; Stephens, T.; Pasamehmetoglu, K. O.; Graham, A. L. & Edwards, J. N.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Advanced in Macrostatistical Hydrodynamics

Description: An overview is presented of research that focuses on slow flows of suspensions in which colloidal and inertial effects are negligibly small (Macrostatistical Hydrodynamics). First, we describe nuclear magnetic resonance imaging experiments to quantitatively measure particle migration occurring in concentrated suspensions undergoing a flow with a nonuniform shear rate. These experiments address the issue of how the flow field affects the microstructure of suspensions. In order to understand the … more
Date: August 1, 1993
Creator: Graham, A. L.; Tetlow, N.; Abbott, J. R.; Mondy, L. S. & Brenner, H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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A three-phase centrifuge to minimize waste from production tank bottoms and sludges: An economic analysis

Description: The performance of a three-phase centrifuge process in separating tank bottoms into salable oil, brine and solids was scaled using the sigma method. The profitability was analyzed for a range of processed volumes for three business scenarios: producer owned, service company and a disposal facility. Centrifuge processes operated at full capacity in these situations may be very profitable investments but any investment decision should be heavily influenced by the annual volume to be processed, th… more
Date: March 1, 1995
Creator: Polston, C. E.; Parkinson, W. J.; Graham, A. L.; Steele, R. D. & Bretz, R. E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Maximizing Storage Rate and Capacity and Insuring the Environmental Integrity of Carbon Dioxide Sequestration in Geological Reservoirs

Description: Maximizing Storage Rate and Capacity and Insuring the Environmental Integrity of Carbon Dioxide Sequestration in Geological Formations The U.S. and other countries may enter into an agreement that will require a significant reduction in CO2 emissions in the medium to long term. In order to achieve such goals without drastic reductions in fossil fuel usage, CO2 must be removed from the atmosphere and be stored in acceptable reservoirs. The research outlined in this proposal deals with developing… more
Date: December 7, 2005
Creator: Davis, L. A.; Graham, A. L.; Parker, H. W.; Abbott, J. R.; Ingber, M. S.; Mammoli, A. A. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Hydrodynamic particle migration in small-amplitude, oscillatory, circular couette flow: The limits of reversibility

Description: Initially well-mixed suspensions of large spherical particles in viscous Newtonian fluids subjected to continuous nonhomogeneous shear flows demix and establish large concentration gradients. A number of experimental studies have determined that the particles migrate to the low shear-rate region in one-dimensional flow fields. Other investigators have proposed mechanisms to model the migration caused by the presence of nonuniform shear gradients. Here, we report on the shear-induced migration o… more
Date: January 1, 1992
Creator: Brenner, H. (Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Chemical Engineering); Altobelli, S. A. (Lovelace Medical Foundation, Albuquerque, NM (United States)); Graham, A. L.; Abbott, J. R. (Los Alamos National Lab., NM (United States)) & Monday, L. A. (Sandia National Labs., Albuquerque, NM (United States))
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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