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Experimental study of flame propagation in semiconfined geometries with obstacles

Description: Accidents in which large quantities of liquefied natural gas (LNG) or other combustible materials are spilled can potentially lead to disastrous consequences, especially if the dispersing combustible cloud finds a suitable ignition source. So far, very little is known about the detailed behavior of a large burning cloud. Full-scale experiments are economically prohibitive, and therefore one must rely on laboratory and field experiments of smaller size, scaling up the results to make predictions… more
Date: February 8, 1982
Creator: Urtiew, P.A.; Brandeis, J. & Hogan, W.J.
Partner: UNT Libraries Government Documents Department
open access

Multivariable current control for electrically and magnetically coupled superconducting magnets. Revision 1

Description: Superconducting magnet systems under construction and projected for the future contain magnets that are magnetically coupled and electrically connected with shared power supplies. A change in one power supply voltage affects all of the magnet currents. A current controller for these system must be designed as a multivariable system. The power describes a method, based on decoupling control, for the rational design of these systems. Dynamic decoupling is achieved by cross-feedback of the measure… more
Date: February 8, 1985
Creator: Owen, E. W. & Shimer, D. W.
Partner: UNT Libraries Government Documents Department
open access

A Detailed Chemical Kinetic Reaction Mechanism for Oxidation of Four Small Alkyl Esters in Laminar Premixed Flames

Description: A detailed chemical kinetic reaction mechanism has been developed for a group of four small alkyl ester fuels, consisting of methyl formate, methyl acetate, ethyl formate and ethyl acetate. This mechanism is validated by comparisons between computed results and recently measured intermediate species mole fractions in fuel-rich, low pressure, premixed laminar flames. The model development employs a principle of similarity of functional groups in constraining the H atom abstraction and unimolecul… more
Date: February 8, 2008
Creator: Westbrook, C K; Pitz, W J; Westmoreland, P R; Dryer, F L; Chaos, M; Osswald, P et al.
Partner: UNT Libraries Government Documents Department
open access

Modeling Hydraulic Responses to Meteorological Forcing: fromCanopy to Aquifer

Description: An understanding of the hydrologic interactions amongatmosphere, land surface, and subsurface is one of the keys tounderstanding the water cycling system that supports our life system onearth. Properly modeling such interactionsis a difficult task because oftheinherent coupled processes and complex feedback structures amongsubsystems. In this paper, we present a model that simulates thelandsurface and subsurface hydrologic response to meteorological forcing.This model combines a state of the ar… more
Date: February 8, 2007
Creator: Pan, Lehua; Jin, Jiming; Miller, Norman; Wu, Yu-Shu & Bodvarsson,Gudmundur
Partner: UNT Libraries Government Documents Department
open access

SAVANNAH RIVER NATIONAL LABORATORY HYDROGEN TECHNOLOGY RESEARCH

Description: The Savannah River National Laboratory (SRNL) is a U.S. Department of Energy research and development laboratory located at the Savannah River Site (SRS) near Aiken, South Carolina. SRNL has over 50 years of experience in developing and applying hydrogen technology, both through its national defense activities as well as through its recent activities with the DOE Hydrogen Programs. The hydrogen technical staff at SRNL comprises over 90 scientists, engineers and technologists, and it is believed… more
Date: February 8, 2008
Creator: Danko, E
Partner: UNT Libraries Government Documents Department
open access

In-situ monitoring of surface post-processing in large aperture fused silica optics with Optical Coherence Tomography

Description: Optical Coherence Tomography is explored as a method to image laser-damage sites located on the surface of large aperture fused silica optics during post-processing via CO{sub 2} laser ablation. The signal analysis for image acquisition was adapted to meet the sensitivity requirements for this application. A long-working distance geometry was employed to allow imaging through the opposite surface of the 5-cm thick optic. The experimental results demonstrate the potential of OCT for remote monit… more
Date: February 8, 2008
Creator: Guss, G M; Bass, I l; Hackel, R P; Mailhiot, C & Demos, S G
Partner: UNT Libraries Government Documents Department
open access

A New Stabilized Nodal Integration Approach

Description: A new stabilized nodal integration scheme is proposed and implemented. In this work, focus is on the natural neighbor meshless interpolation schemes. The approach is a modification of the stabilized conforming nodal integration (SCNI) scheme and is shown to perform well in several benchmark problems.
Date: February 8, 2006
Creator: Puso, M; Zywicz, E & Chen, J S
Partner: UNT Libraries Government Documents Department
open access

Autofluorescence dynamics during reperfusion following long-term renal ischemia in a rat model

Description: Optical properties of near-surface kidney tissue were monitored in order to assess response during reperfusion to long (20 minutes) versus prolonged (150 minutes) ischemia in an in vivo rat model. Specifically, autofluorescence images of the exposed surfaces of both the normal and the ischemic kidneys were acquired during both injury and reperfusion alternately under 355 nm and 266 nm excitations. The temporal profile of the emission of the injured kidney during the reperfusion phase under 355 … more
Date: February 8, 2008
Creator: Raman, R N; Pivetti, C D; Matthews, D L; Troppmann, C & Demos, S G
Partner: UNT Libraries Government Documents Department
open access

Multivariable current control for electrically and magnetically coupled superconducting magnets

Description: Superconducting magnet systems under construction and projected for the future contain magnets that are magnetically coupled and electrically connected with shared power supplies. A change in one power supply voltage affects all of the magnet currents. A current controller for these systems must be designed as a multivariable system. The paper describes a method, based on decoupling control, for the rational design of these systems. Dynamic decoupling is achieved by cross-feedback of the measur… more
Date: February 8, 1985
Creator: Owen, E. W. & Shimer, D. W.
Partner: UNT Libraries Government Documents Department
open access

Observation of excited H/sup 0/ atoms produced by relativistic H/sup /minus// ions in carbon and formvar foils

Description: We have measured the relative yield of several low-lying excited states of neutral hydrogen atoms produced by the passage of 226-MeV and 581-MeV H/sup /minus// ions through thin carbon foils and a tilted formvar foil. The relative yields of H/sup /minus///sub /asterisk//(n = 2,3, 4) were measured for 17 different carbon foils ranging in thickness from 662 /angstrom/ to 5386 /angstrom/ at 581 MeV. The relative yield of H/sup 0//sup /asterisk//(n = 2) was also measured for these carbon foils at 2… more
Date: February 8, 1989
Creator: Mohagheghi, A. H.; Bryant, H. C.; Harris, P. G.; Tang, C. Y.; Quick, C. R.; Reeder, R. A. et al.
Partner: UNT Libraries Government Documents Department
open access

Progress Toward the Analysis of the Kinetic Stabilizer Concept

Description: The Kinetic Stabilizer (K-S) concept [1] represents a means for stabilizing axisymmetric mirror and tandem-mirror (T-M) magnetic fusion systems against MHD interchange instability modes. Magnetic fusion research has given us examples of axisymmetric mirror confinement devices in which radial transport rates approach the classical ''Spitzer'' level, i.e. situations in which turbulence if present at all, is at too low a level to adversely affect the radial transport [2,3,4]. If such a low-turbule… more
Date: February 8, 2005
Creator: Post, R. F.; Byers, J. A.; Cohen, R. H.; Fowler, T. K.; Ryutov, D. D. & Tung, L. S.
Partner: UNT Libraries Government Documents Department
open access

Optimal Segmentation Strategy for Compact Representation of Hyperspectral Image Cubes

Description: By producing compact representations of hyperspectral image cubes (hypercubes), image storage requirements and the amount of time it takes to extract essential elements of information can both be dramatically reduced. However, these compact representations must preserve the important spectral features within hypercube pixels and the spatial structure associated with background and objects or phenomena of interest. This paper describes a novel approach for automatically and efficiently generatin… more
Date: February 8, 2000
Creator: Paglieroni, D & Roberts, R
Partner: UNT Libraries Government Documents Department
open access

The Physics of Ion Decoupling in Magnetized Plasma Explosions

Description: When a finite pulse of plasma expands into a magnetized background plasma, MHD predicts the pulse expel background plasma and its B-field - i.e. cause a magnetic 'bubble'. The expanding plasma is confined within the bubble, later to escape down the B-field lines. MHD suggests that the debris energy goes to expelling the B-field from the bubble volume and kinetic energy of the displaced background. For HANEs, this is far from the complete story. For many realistic HANE regimes, the long mean-fre… more
Date: February 8, 2011
Creator: Hewett, D; Larson, D & Brecht, S
Partner: UNT Libraries Government Documents Department
open access

Recent studies of short-range order in alloys: The Cowley theory revisited

Description: We present comparisons of various statistical theories for effective pair interactions (EPI) in alloys. We then evaluate these EPI`s using the Cowley theory, the Krivoglaz-Clapp-Moss (KCM) approximation, the {gamma}-expansion method (GEM) of Tokar, Masanskii and coworkers, and the exact inverse Monte Carlo (IMC) method, introduced by Gerold and Kern. Via a series of model calculations on a hypothetical bcc alloy with a single nearest-neighbor interaction we show that the Cowley theory is succes… more
Date: February 8, 1993
Creator: Reinhard, L. & Moss, S. C.
Partner: UNT Libraries Government Documents Department
open access

Crevice Repassivation Potential of Alloy 22 in High-Nitrate Dust Deliquescence Type Environments

Description: The nitrate ion (NO{sub 3}{sup -}) is an inhibitor for crevice corrosion of Alloy 22 (N06022) in chloride (Cl{sup -}) aqueous solutions. Naturally formed electrolytes may contain both chloride and nitrate ions. The higher the ratio R = [NO{sub 3}{sup -}]/[Cl{sup -}] in the solution the stronger the inhibition of crevice corrosion. Atmospheric desert dust contains both chloride and nitrate salts, generally based on sodium (Na{sup +}) and potassium (K{sup +}). Some of these salts may deliquescenc… more
Date: February 8, 2007
Creator: Lian, T; Gdowski, G E; Hailey, P D & Rebak, R B
Partner: UNT Libraries Government Documents Department
open access

Effective Medium Theories for Multicomponent Poroelastic Composites

Description: In Biot's theory of poroelasticity, elastic materials contain connected voids or pores and these pores may be filled with fluids under pressure. The fluid pressure then couples to the mechanical effects of stress or strain applied externally to the solid matrix. Eshelby's formula for the response of a single ellipsoidal elastic inclusion in an elastic whole space to a strain imposed at a distant boundary is a very well-known and important result in elasticity. Having a rigorous generalization o… more
Date: February 8, 2005
Creator: Berger, E. L.
Partner: UNT Libraries Government Documents Department
open access

The Comparison and Evaluation of Three Fiber Composite Failure Criteria

Description: Three specific failure criteria for the transversely isotropic fiber composite case will be discussed. All three use the polynomial expansion method. The three criteria are the Tsai-Wu criterion, the Hashin criterion and the Christensen criterion. All three criteria will be given in forms that admit direct and easy comparison, which has not usually been done. The central differences between these three criteria will be discussed, and steps will be taken toward the evaluation of them.
Date: February 8, 2005
Creator: Christensen, R M
Partner: UNT Libraries Government Documents Department
open access

Gene expression signature in organized and growth arrested mammaryacini predicts good outcome in breast cancer

Description: To understand how non-malignant human mammary epithelial cells (HMEC) transit from a disorganized proliferating to an organized growth arrested state, and to relate this process to the changes that occur in breast cancer, we studied gene expression changes in non-malignant HMEC grown in three-dimensional cultures, and in a previously published panel of microarray data for 295 breast cancer samples. We hypothesized that the gene expression pattern of organized and growth arrested mammary acini w… more
Date: February 8, 2006
Creator: Fournier, Marcia V.; Martin, Katherine J.; Kenny, Paraic A.; Xhaja, Kris; Bosch, Irene; Yaswen, Paul et al.
Partner: UNT Libraries Government Documents Department
open access

THE U.S. DEPARTMENT OF ENERGY-OFFICE OF ENVIRONMENTAL MANAGEMENT'S INTERNATIONAL PROGRAM

Description: The U.S. Department of Energy's (DOE) Office of Environmental Management (EM) has collaborated with the various international institutes (e.g. Russian Federal Atomic Energy Agency--Rosatom and Ukraine government's Chornobyl Center-International Radioecology Laboratory (CC-IRL)) for many years on radioactive waste management challenges of mutual concern. Currently, EM is cooperating with Rosatom and the Ukraine's CC-IRL to explore issues related to high-level waste and to investigate experience … more
Date: February 8, 2007
Creator: Harbour, J; James Marra, J; David Peeler, D; Jay Roach (NOEMAIL), J & Bond Calloway, B
Partner: UNT Libraries Government Documents Department
open access

Excitation Cross Section Measurement for n=3 to n=2 Line Emission in Fe17+ to Fe23+

Description: The authors report the measurement of electron impact excitation cross sections for the strong iron L-shell 3 {yields} 2 lines of Fe XVIII through Fe XXIV at the EBIT-I electron beam ion trap using a crystal spectrometer and a 6 x 6 pixel array microcalorimeter. The cross sections were determined by direct normalization to the well established cross section of radiative electron capture through a sophisticated model analysis which results in the excitation cross section for 48 lines at multiple… more
Date: February 8, 2006
Creator: Chen, H; Gu, M F; Beiersdorfer, P; Boyce, K R; Brown, G V; Kahn, S M et al.
Partner: UNT Libraries Government Documents Department
open access

Combined plate motion and density driven flow in the asthenosphere beneath Saudi Arabia: Evidence from shear-wave splitting and seismic anisotropy

Description: A comprehensive study of mantle anisotropy along the Red Sea and across Saudi Arabia was performed by analyzing shear-wave splitting recorded by stations from three different seismic networks: the largest, most widely distributed array of stations examined across Saudi Arabia to date. Stations near the Gulf of Aqaba display fast orientations that are aligned parallel to the Dead Sea Transform Fault, most likely related to the strike-slip motion between Africa and Arabia. However, most of our ob… more
Date: February 8, 2006
Creator: Hansen, S & Schwartz, S
Partner: UNT Libraries Government Documents Department
open access

Adiabatic shear band formation in explosively driven AerMet-100 alloy cylinders

Description: Two differently heat-treated AerMet-100 alloy cylinders were explosively driven to fragmentation. Soft-captured fragments were studied to characterize the deformation and damage induced by high explosive loading. The characterization of the fragments reveals that the dominant failure mechanism appears to be dynamic fracture along adiabatic shear bands. These shear bands differ in size and morphology depending on the heat-treated conditions. Nanoindentation measurements of the adiabatic shear ba… more
Date: February 8, 2006
Creator: Sunwoo, A J; Becker, R; Goto, D M; Orzechowski, T J; Springer, H K; Syn, C K et al.
Partner: UNT Libraries Government Documents Department
open access

Climate Change in Lowland Central America During the Late Deglacial and Early Holocene

Description: The transition from arid glacial to moist early Holocene conditions represented a profound change in northern lowland Neotropical climate. Here we report a detailed record of changes in moisture availability during the latter part of this transition ({approx}11,250 to 7,500 cal yr BP) inferred from sediment cores retrieved in Lake Peten Itza, northern Guatemala. Pollen assemblages demonstrate that a mesic forest had been largely established by {approx}11,250 cal yr BP, but sediment properties i… more
Date: February 8, 2005
Creator: Hillesheim, M. B.; Hodell, D. A.; Leyden, B. W.; Brenner, M.; Curtis, J. H.; Anselmetti, F. S. et al.
Partner: UNT Libraries Government Documents Department
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