Yates, D.N. Jr.; Myers, W.D.
1991-11-26T23:59:59.000Z
This patent describes a perforating gun for insertion in a wellbore into a formation. It includes a tubular housing and a tubular element, defining a flow passage.
Donovan, J.F.; Naquin, M.J.
1991-12-31T23:59:59.000Z
This patent describes a system for preparing a formation to allow hydrocarbons to be produced from a well. It comprises an elongated perforating gun; means extending from the outer periphery of the gun, in a generally radial direction from its longitudinal axis, for facilitating extraction of the gun from the well, the means operable when the gun is covered with a solid material delivered into the well and lodged between the formation and the gun; and the means imparting a longitudinal extractive force when the gun is rotated along its longitudinal axis.
Manifold Integration: Data Integration on Multiple Manifolds
Choi, Hee Youl
2011-08-08T23:59:59.000Z
MANIFOLD INTEGRATION: DATA INTEGRATION ON MULTIPLE MANIFOLDS A Dissertation by HEE YOUL CHOI Submitted to the O?ce of Graduate Studies of Texas A&M University in partial fulflllment of the requirements for the degree of DOCTOR OF PHILOSOPHY... May 2010 Major Subject: Computer Science MANIFOLD INTEGRATION: DATA INTEGRATION ON MULTIPLE MANIFOLDS A Dissertation by HEE YOUL CHOI Submitted to the O?ce of Graduate Studies of Texas A&M University in partial fulflllment of the requirements...
Tubing carried perforating gun with insulation jacket
Donovan, J.F.; Yates, D.N.
1991-05-21T23:59:59.000Z
This patent describes a method of insulating a tubing carried perforating gun which is run through a subterranean wellbore. It includes making up at the well surface a tubing string for introduction within the well, the tubing string carrying a perforating gun assembly.
High power laser perforating tools and systems
Zediker, Mark S; Rinzler, Charles C; Faircloth, Brian O; Koblick, Yeshaya; Moxley, Joel F
2014-04-22T23:59:59.000Z
ystems devices and methods for the transmission of 1 kW or more of laser energy deep into the earth and for the suppression of associated nonlinear phenomena. Systems, devices and methods for the laser perforation of a borehole in the earth. These systems can deliver high power laser energy down a deep borehole, while maintaining the high power to perforate such boreholes.
Hildebrand, Richard J. (Edgemere, MD); Wozniak, John J. (Columbia, MD)
2001-01-01T23:59:59.000Z
A compressed gas storage cell interconnecting manifold including a thermally activated pressure relief device, a manual safety shut-off valve, and a port for connecting the compressed gas storage cells to a motor vehicle power source and to a refueling adapter. The manifold is mechanically and pneumatically connected to a compressed gas storage cell by a bolt including a gas passage therein.
Zeghib, Abdelghani
Dynamics on Lorentz manifolds Abdelghani Zeghib Introduction Motivations and questions Examples Results Results Previous results Linear Dynamics General considerations Furstenberg Lemma Lorentz Dynamics://www.umpa.ens-lyon.fr/~zeghib/ (joint work with Paolo Piccione) #12;Dynamics on Lorentz manifolds Abdelghani Zeghib Introduction
Dispersant solutions for dispersing hydrocarbons
Tyndall, Richard L. (Clinton, TN)
1997-01-01T23:59:59.000Z
A dispersant solution includes a hydrocarbon dispersing solution derived from a bacterium from ATCC 75527, ATCC 75529, or ATCC 55638.
Dispersant solutions for dispersing hydrocarbons
Tyndall, R.L.
1997-03-11T23:59:59.000Z
A dispersant solution includes a hydrocarbon dispersing solution derived from a bacterium from ATCC 75527, ATCC 75529, or ATCC 55638.
Perforation of thin unreinforced concrete slabs
Cargile, J.D. [Army Engineer Waterways Experiment Station, Vicksburg, MS (United States); Giltrud, M.E. [Defense Nuclear Agency, Washington, DC (United States); Luk, V.K. [Sandia National Labs., Albuquerque, NM (United States)
1993-10-01T23:59:59.000Z
This report discusses fourteen tests which were conducted to investigate the perforation of thin unreinforced concrete slabs. The 4340-steel projectile used in the test series is 50.8 mm in diameter, 355.6 mm in length, has a mass of 2.34 kg. and an ogive nose with caliber radius head of 3. The slabs, contained within steel culverts, are 1.52 m in diameter and consist of concrete with a nominal unconfined compressive strength of 38.2 MPa and maxima aggregate size of 9.5 mm. Slab thicknesses are 284.4, 254.0, 215.9 and 127.0 mm. Tests were conducted at impact velocities of about 313 m/s on all slab thicknesses and about 379 and 471 m/s on the 254.0-mm-thick slab. All tests were conducted at normal incidence to the slab. All tests were conducted at normal incidence to the slab. Information obtained from the tests used to determine the loading (deceleration) on the projectile during the perforation process, the velocity-displacement of the projectile as it perforated the slab, and the projectile position as damage occurred on the backface of the slab. The test projectile behaved essentially as a rigid body for all of the tests.
Einstein manifolds with skew torsion
Ilka Agricola; Ana Cristina Ferreira
2013-02-15T23:59:59.000Z
This paper is devoted to the first systematic investigation of manifolds that are Einstein for a connection with skew symmetric torsion. We derive the Einstein equation from a variational principle and prove that, for parallel torsion, any Einstein manifold with skew torsion has constant scalar curvature; and if it is complete of positive scalar curvature, it is necessarily compact and it has finite first fundamental group. The longest part of the paper is devoted to the systematic construction of large families of examples. We discuss when a Riemannian Einstein manifold can be Einstein with skew torsion. We give examples of almost Hermitian, almost metric contact, and G2 manifolds that are Einstein with skew torsion. For example, we prove that any Einstein-Sasaki manifold and any 7-dimensional 3-Sasakian manifolds admit deformations into an Einstein metric with parallel skew torsion.
Pressure enhanced penetration with shaped charge perforators
Glenn, Lewis A. (Danville, CA)
2001-01-01T23:59:59.000Z
A downhole tool, adapted to retain a shaped charge surrounded by a superatmospherically pressurized light gas, is employed in a method for perforating a casing and penetrating reservoir rock around a wellbore. Penetration of a shaped charge jet can be enhanced by at least 40% by imploding a liner in the high pressure, light gas atmosphere. The gas pressure helps confine the jet on the axis of penetration in the latter stages of formation. The light gas, such as helium or hydrogen, is employed to keep the gas density low enough so as not to inhibit liner collapse.
Method and apparatus for selective retraction of a tubing carried perforating gun
Rubbo, R.P.
1990-12-25T23:59:59.000Z
This patent describes apparatus for telescopically retracting a subterranean well tubing carried perforating gun.
Poincare's Conjecture for three manifolds
G. S. Makanin
2007-11-23T23:59:59.000Z
We prove Poincare's Conjecture that every simply connected, closed three-manifold is topologically equivalent to the three-sphere. The proof is founded on the algebraic formulation discovered by J. Stallings.
Evaluation of Perforated Carbonate Cores Under Acid Stimulation
Diaz, Nerwing Jose
2011-10-21T23:59:59.000Z
Although it has been shown that clean perforation tunnels facilitate the evolution of a single, deeper-penetrating wormhole, there are no reported applications of reactive shaped charges in carbonates prior to acid stimulation. The present study...
Impact perforation of monolithic polyethylene plates: projectile nose shape dependence
Mohagheghian, I.; McShane, G. J.; Stronge, W. J.
2015-02-12T23:59:59.000Z
. The perforation mechanisms and energy absorption of these PE plates are contrasted with those of thin aluminium alloy targets that have the same total mass. UHMWPE outperforms these metallic targets for all three projectile nose shapes. Finally, the influence...
Simplicial isotopies in 3-manifolds
O'Donnell, Daniel Francis
1974-01-01T23:59:59.000Z
SIMPLICIAL ISOTOPIES IN 3-MANIFOLDS A Thesis DANIEL FRANCIS O'OONNELL Submitted to the Graduate College of Texas A&fl Uniuersity in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE August, 1974 Major Subject...: Mathematics SIMPLICIAL ISOTOPIES IN 3-MANIFOLDS A Thesis by DANIEL FRANCIS O'DONNELL Approved as to style and content by: (Chairman of Committee) (Head of (Member) (Member) August 1974 ABSTRACT Simplicial Isotopies in 3-Mani folds. (August 1974...
Finding Transition Pathways on Manifolds
Tiejun Li; Xiaoguang Li; Xiang Zhou
2014-08-13T23:59:59.000Z
We consider noise-induced transition paths in randomly perturbed dynami- cal systems on a smooth manifold. The classical Freidlin-Wentzell large devia- tion theory in Euclidean spaces is generalized and new forms of action functionals are derived in the spaces of functions and the space of curves to accommodate the intrinsic constraints associated with the manifold. Numerical meth- ods are proposed to compute the minimum action paths for the systems with constraints. The examples of conformational transition paths for a single and double rod molecules arising in polymer science are numerically investigated.
Characterization of cardiac lead perforation risk via a dynamic simulated environment
Rosario, Matthew J
2012-01-01T23:59:59.000Z
Delayed cardiac perforation is a serious medical condition where an implanted cardiac lead migrates through the heart wall, causing life-threatening complications. Where acute perforation occurs during implant, delayed ...
Tubing pressurized firing apparatus for a tubing conveyed perforating gun
Davies, D. L.
1985-11-26T23:59:59.000Z
A tubing pressurized firing apparatus is shown for use with a tubing conveyed perforating gun of the type used to perforate a cased well bore. The firing apparatus has a tubular body with an upper end for connection in the well tubing string and with a lower end for connection to a well perforating gun. An inner mandrel is slidably mounted within the tubular body and has a ball seat formed in the interior bore thereof for receiving a ball dropped through the well tubing string. The ball and ball seat together form a pressure tight seal whereby tubing pressure in the well tubing string acts on the inner mandrel to slide the mandrel downwardly within the tubular body. A cocking mechanism located below the inner mandrel within the body includes a lockout member which is initially positioned between a detonating pin and a percussion detonator. The cocking mechanism is actuated by downward sliding movement of the inner mandrel to move the lockout member from between the detonating pin and percussion detonator whereby a subsequent release of tubing pressure and upward sliding movement of the inner mandrel exposes the detonating pin to the percussion detonator to actuate the detonator and fire the perforating gun.
Efficiency of perforated breakwater and associated energy dissipation
Ariyarathne, Hanchapola Appuhamilage
2009-05-15T23:59:59.000Z
The flow field behavior in the vicinity of a perforated breakwater and the efficiency of the breakwater under regular waves were studied. To examine the efficiency of the structure thirteen types of regular wave conditions with wave periods T = 1, 1...
Efficiency of perforated breakwater and associated energy dissipation
Ariyarathne, Hanchapola Appuhamilage
2008-10-10T23:59:59.000Z
The flow field behavior in the vicinity of a perforated breakwater and the efficiency of the breakwater under regular waves were studied. To examine the efficiency of the structure thirteen types of regular wave conditions with wave periods T = 1, 1...
Apparatus and method for sealing perforated well casing
Blount, C.G.; Benham, R.A.; Brock, J.L.; Emerson, J.A.; Ferguson, K.R.; Scheve, D.F.; Schmidt, J.H.; Schuler, K.W.; Stanton, P.L.
1997-03-25T23:59:59.000Z
Perforations and other openings in well casings, liners and other conduits may be substantially blocked or sealed to prevent fluid flow between the casing or liner interior and an earth formation by placing a radially expansible sleeve adjacent the perforations or openings and urging the sleeve into forcible engagement with the casing or inner wall using an explosive charge. An apparatus including a radially contracted sleeve formed by a coiled plate member or a tubular member having flutes defined by external and internal folds, may be deployed into a well casing or liner through a production or injection tubing string and on the end of a flexible cable or coilable tubing. An explosive charge disposed on the apparatus and within the sleeve may be detonated to urge the sleeve into forcible engagement with the casing inner wall. 17 figs.
Geometric control of failure behavior in perforated sheets
Michelle M. Driscoll
2014-11-20T23:59:59.000Z
Adding perforations to a continuum sheet allows new modes of deformation, and thus modifies its elastic behavior. The failure behavior of such a perforated sheet is explored, using a model experimental system: a material containing a one-dimensional array of rectangular holes. In this model system, a transition in failure mode occurs as the spacing and aspect ratio of the holes are varied: rapid failure via a running crack is completely replaced by quasi-static failure which proceeds via the breaking of struts at random positions in the array of holes. I demonstrate that this transition can be connected to the loss of stress enhancement which occurs as the material geometry is modified.
Simplicial isotopies in 3-manifolds
O'Donnell, Daniel Francis
1974-01-01T23:59:59.000Z
by Treybig [6] of a theorem by Moise [3]. To prove it, we need the following lemma and theorem. Lemma 3. 1. Let P be a polyhedral 2-sphere and let L (u) p be a family of planes in E normal to a given unit vector u so that (a) the vertices of P are a.... E. E. MOise, Affine structures in 3-manifoMs. II. Positional properties of 2-spheres, Ann. of Math. 55(1952), 172 - 176. 4. D. E. Sanderson, Isotopy in 3-manifolds. I. Isotopic deform- mations of 2-cells and 3-cells, Proc. Amer. Math. Soc. 8...
Tenenbaum, Josh
Poverty of the Stimulus? A Rational Approach Amy Perfors1 (perfors@mit.edu), Joshua B. Tenenbaum1, MIT; 2 Department of Psychology, University of Chicago Abstract The Poverty of the Stimulus (Po that these generalizations can best be explained by innate knowledge, known as the argument from the Poverty of the Stimulus
Perforated plates for cryogenic regenerators and method of fabrication
Hendricks, J.B.
1994-03-29T23:59:59.000Z
Perforated plates having very small holes with a uniform diameter throughout the plate thickness are prepared by a [open quotes]wire drawing[close quotes] process in which a billet of sacrificial metal is disposed in an extrusion can of the plate metal, and the can is extruded and restacked repeatedly, converting the billet to a wire of the desired hole diameter. At final size, the rod is then sliced into wafers, and the wires are removed by selective etching. This process is useful for plate metals of interest for high performance regenerator applications, in particular, copper, niobium, molybdenum, erbium, and other rare earth metals. Er[sub 3]Ni, which has uniquely favorable thermophysical properties for such applications, may be incorporated in regions of the plates by providing extrusion cans containing erbium and nickel metals in a stacked array with extrusion cans of the plate metal, which may be copper. The array is heated to convert the erbium and nickel metals to Er[sub 3]Ni. Perforated plates having two sizes of perforations, one of which is small enough for storage of helium, are also disclosed. 10 figures.
Perforated plates for cryogenic regenerators and method of fabrication
Hendricks, John B. (Huntsville, AL)
1994-01-01T23:59:59.000Z
Perforated plates (10) having very small holes (14) with a uniform diameter throughout the plate thickness are prepared by a "wire drawing" process in which a billet of sacrificial metal is disposed in an extrusion can of the plate metal, and the can is extruded and restacked repeatedly, converting the billet to a wire of the desired hole diameter. At final size, the rod is then sliced into wafers, and the wires are removed by selective etching. This process is useful for plate metals of interest for high performance regenerator applications, in particular, copper, niobium, molybdenum, erbium, and other rare earth metals. Er.sub.3 Ni, which has uniquely favorable thermophysical properties for such applications, may be incorporated in regions of the plates by providing extrusion cans (20) containing erbium and nickel metals in a stacked array (53) with extrusion cans of the plate metal, which may be copper. The array is heated to convert the erbium and nickel metals to Er.sub.3 Ni. Perforated plates having two sizes of perforations (38, 42), one of which is small enough for storage of helium, are also disclosed.
Optimal Transportation on Sub-Riemannian Manifolds
Rifford, Ludovic
Optimal Transportation on Sub-Riemannian Manifolds Ludovic Rifford UniversitÂ´e de Nice - Sophia Antipolis (Joint work with A. Figalli) Ludovic Rifford Optimal Transportation on Sub-Riemannian Manifolds #12;Monge's Optimal Transportation Problem Let M be a separable metric space equipped with its Borel
Optimal Transportation on Sub-Riemannian Manifolds
Rifford, Ludovic
Optimal Transportation on Sub-Riemannian Manifolds Ludovic Rifford UniversitÂ´e de Nice - Sophia Antipolis (Joint work with A. Figalli) Ludovic Rifford Optimal Transportation on Sub-Riemannian Manifolds #12;Outline I. Statement of our optimal transportation problem II. Sketch of proof of the Mc
Magnetic Resonance Imaging (MRI) of PEM Dehydration and Gas Manifold...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Resonance Imaging (MRI) of PEM Dehydration and Gas Manifold Flooding During Continuous Fuel Cell Operation. Magnetic Resonance Imaging (MRI) of PEM Dehydration and Gas Manifold...
Heterotic Model Building: 16 Special Manifolds
Yang-Hui He; Seung-Joo Lee; Andre Lukas; Chuang Sun
2014-05-13T23:59:59.000Z
We study heterotic model building on 16 specific Calabi-Yau manifolds constructed as hypersurfaces in toric four-folds. These 16 manifolds are the only ones among the more than half a billion manifolds in the Kreuzer-Skarke list with a non-trivial first fundamental group. We classify the line bundle models on these manifolds, both for SU(5) and SO(10) GUTs, which lead to consistent supersymmetric string vacua and have three chiral families. A total of about 29000 models is found, most of them corresponding to SO(10) GUTs. These models constitute a starting point for detailed heterotic model building on Calabi-Yau manifolds in the Kreuzer-Skarke list. The data for these models can be downloaded here: http://www-thphys.physics.ox.ac.uk/projects/CalabiYau/toricdata/index.html
Cottle, John Ernest
1948-01-01T23:59:59.000Z
of the question. Other difficulties encountered. in the use of large packed columns are the tendeno1es of the liquid to channel through the paoking and. of the packing to break down under high operating temperatures. Hubble cap plate columns are the most...- oulty in a perforated. plate column than in any other types' and. should oleaning 'be necessary it could, be aocomplished much more easily. It is also believed that high plate efficienoies could be o'btained with per- i'orated plates 'beoause...
Mechanical seal having a single-piece, perforated mating ring
Khonsari, Michael M. (Baton Rouge, LA); Somanchi, Anoop K. (Fremont, CA)
2007-08-07T23:59:59.000Z
A mechanical seal (e.g., single mechanical seals, double mechanical seals, tandem mechanical seals, bellows, pusher mechanical seals, and all types of rotating and reciprocating machines) with reduced contact surface temperature, reduced contact surface wear, or increased life span. The mechanical seal comprises a rotating ring and a single-piece, perforated mating ring, which improves heat transfer by controllably channeling coolant flow through the single-piece mating ring such that the coolant is in substantially uniform thermal contact with a substantial portion of the interior surface area of the seal face, while maintaining the structural integrity of the mechanical seal and minimizing the potential for coolant flow interruptions to the seal face caused by debris or contaminants (e.g., small solids and trash) in the coolant.
Gauge Theories in Noncommutative Homogeneous Kähler Manifolds
Yoshiaki Maeda; Akifumi Sako; Toshiya Suzuki; Hiroshi Umetsu
2014-09-07T23:59:59.000Z
We construct a gauge theory on a noncommutative homogeneous K\\"ahler manifold, where we employ the deformation quantization with separation of variables for K\\"ahler manifolds formulated by Karabegov. A key point in this construction is to obtaining vector fields which act as inner derivations for the deformation quantization. We show that these vector fields are the only Killing vector fields. We give an explicit construction of this gauge theory on noncommutative ${\\mathbb C}P^N$ and noncommutative ${\\mathbb C}H^N$.
SUSY gauge theory on graded manifolds
G. Sardanashvily; W. Wachowski
2014-06-24T23:59:59.000Z
Lagrangian classical field theory of even and odd fields is adequately formulated in terms of fibre bundles and graded manifolds. In particular, conventional Yang-Mills gauge theory is theory of connections on smooth principal bundles, but its BRST extension involves odd ghost fields an antifields on graded manifolds. Here, we formulate Yang-Mills theory of Grassmann-graded gauge fields associated to Lie superalgebras on principal graded bundles. A problem lies in a geometric definition of odd gauge fields. Our goal is Yang--Mills theory of graded gauge fields and its BRST extension.
MATH 132: TOPOLOGY II: SMOOTH MANIFOLDS ANDREW COTTON-CLAY
Cotton-Clay, Andrew
MATH 132: TOPOLOGY II: SMOOTH MANIFOLDS ANDREW COTTON-CLAY 1. Introduction My Name: Andrew Cotton-Clay
Numerical simulations of perforated plate stabilized premixed flames with detailed chemistry
Kedia, Kushal Sharad
2010-01-01T23:59:59.000Z
The objective of this work is to develop a high efficiency two-dimensional reactive flow solver to investigate perforated-plate stabilized laminar premixed flames. The developed code is used to examine the impact of the ...
AIP/123-QED Acoustic properties of plates with unevenly distributed macro perforations backed by
Paris-Sud XI, UniversitÃ© de
be a difficult task in practical acoustic engineering applications. Furthermore, drilling a large amount, the best performance for perforated panels is obtained for submillimetric holes. As recom- mended by Maa1
A study of the effects of casing perforations on the production rates of wells
Sanderlin, James Lewis
1958-01-01T23:59:59.000Z
Resistance Values Used to Sinulate Well Bore plus Perfo'rations ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ o ~ ~ ~ ~ ~ $2 III Resistance Values Neasured Using Electrolytic Tank and Conductivity Bridge . . . ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ IV Resistance Values for Plush Perforations 34... coetsat by: ~ ad of Defer ?t AuSest 1958 TRBUL OP CONTEIES introduction snd Review of Literature Materials and Iquipaent . Procedure 6 Electrolytic Tank Electrical dnaloS Model Results snd Discussion of Results 10 Conclusions . *cknowled...
Drilling long geodesics in hyperbolic 3-manifolds K. Bromberg
Bromberg, Kenneth
Drilling long geodesics in hyperbolic 3-manifolds K. Bromberg September 22, 2006 1 Introduction to such a deformation as drilling and results which compare the geometry of the original manifold to the geometry of the drilled manifold as drilling theorems. The first results of this type are due to Hodgson and Kerckhoff
Einstein Manifolds and Contact Geometry Charles P. Boyer Krzysztof Galicki
Einstein Manifolds and Contact Geometry Charles P. Boyer Krzysztof Galicki Abstract. We show that every KÂcontact Einstein manifold is SasakianÂEinstein and discuss several corollaries of this result. 1 types of Riemannian contact manifolds to construct Einstein metrics of positive scalar curvature
EMBEDDINGS IN GENERALIZED MANIFOLDS J. L. BRYANT AND W. MIO
Aluffi, Paolo
EMBEDDINGS IN GENERALIZED MANIFOLDS J. L. BRYANT AND W. MIO Abstract. We prove that a (2m \\Gamma n grant DMSÂ9626624. 1 #12; 2 J. L. BRYANT AND W. MIO theory, for removing intersections of manifoldsÂmanifold with the DDP , n â?? 5, could be approximated by embeddings [5]. Bryant [2] and Walsh [20] were able to establish
Manifold gasket accommodating differential movement of fuel cell stack
Kelley, Dana A. (New Milford, CT); Farooque, Mohammad (Danbury, CT)
2007-11-13T23:59:59.000Z
A gasket for use in a fuel cell system having at least one externally manifolded fuel cell stack, for sealing the manifold edge and the stack face. In accordance with the present invention, the gasket accommodates differential movement between the stack and manifold by promoting slippage at interfaces between the gasket and the dielectric and between the gasket and the stack face.
Large-Scale Manifold Learning Ameet Talwalkar
California at Irvine, University of
Large-Scale Manifold Learning Ameet Talwalkar Courant Institute New York, NY ameet on spectral decom- position, we first analyze two approximate spectral decom- position techniques for large-dimensional embeddings for two large face datasets: CMU-PIE (35 thousand faces) and a web dataset (18 million faces). Our
DIRECT SEARCH METHODS OVER LIPSCHITZ MANIFOLDS 1 ...
2007-02-27T23:59:59.000Z
Page 1 ... (implicit) function theorem allows us to define a new problem on the tangent spaces of the manifold. .... modification to our algorithm in Procedure 2.1, though now the convergence analysis is done in TxM. .... First we'll concern ourselves with finding the implicit function ?(0, w). What ... The reason is, we don'
Collisions at infinity in hyperbolic manifolds
McReynolds, D B; Stover, Matthew
2012-01-01T23:59:59.000Z
For a complete, finite volume real hyperbolic n-manifold M, we investigate the map between homology of the cusps of M and the homology of $M$. Our main result provides a proof of a result required in a recent paper of Frigerio, Lafont, and Sisto.
Energy-momentum balance in particle - domain wall perforating collision
D. V. Gal'tsov; E. Yu. Melkumova; P. A. Spirin
2015-02-10T23:59:59.000Z
We investigate the energy-momentum balance in the perforating collision of a point particle with an infinitely thin planar domain wall within the linearized gravity in arbitrary dimensions. Since the metric of the wall increases with distance, the wall and the particle are never free, and their energy-momentum balance involves not only the instantaneous kinetic momenta, but also the non-local contribution of gravitational stresses. However, careful analysis shows that the stresses can be unambiguously divided between the colliding objects leading to definition of the gravitationally dressed momenta. These take into account for gravity in the same way as the potential energy does in the non-relativistic theory, but our treatment is fully relativistic. Another unusual feature of our problem is the non-vanishing flux of the total energy-momentum tensor through the lateral surface of the world tube. In this case the zero divergence of the energy-momentum tensor does not imply conservation of the total momentum defined as the integral over the space-like section of the tube. But one can still define the conservation low infinitesimally, passing to time derivatives of the momenta. Using this definition we establish the momentum balance in terms of the dressed particle and wall momenta.
Group manifold approach to higher spin theory
Hu, Shan
2015-01-01T23:59:59.000Z
We consider the group manifold approach to higher spin theory. The deformed higher spin transformation is realized as the diffeomorphism transformation on group manifold $\\textbf{M}$. With the suitable rheonomy condition and the torsion constraint imposed, the unfolded equation can be obtained from the Bianchi identity, by solving which, fields on $\\textbf{M}$ is determined by the multiplet at one point, or equivalently, by $(W^{[a(s-1),b(0)]}_{\\mu},H)$ on $AdS_{4}\\subset \\textbf{M}$. Although the space is extended to $\\textbf{M}$ to get the geometrical formulation, the dynamical degrees of freedom is still in $AdS_{4}$. We also discuss the theory with the global higher spin symmetry, which is in parallel with the WZ model in supersymmetry.
Gorenz, Heather M. (Albuquerque, NM); Brockmann, John E. (Albuquerque, NM); Lucero, Daniel A. (Albuquerque, NM)
2011-09-20T23:59:59.000Z
A powder dispersion method and apparatus comprising an air eductor and a powder dispensing syringe inserted into a suction connection of the air eductor.
Connections on non-symmetric (generalized) Riemannian manifold and gravity
Ivanov, Stefan
2015-01-01T23:59:59.000Z
Connections with (skew-symmetric) torsion on non-symmetric Riemannian manifold satisfying the Einstein metricity condition (NGT with torsion) are considered. It is shown that an almost Hermitian manifold is an NGT with torsion if and only if it is a Nearly K\\"ahler manifold. In the case of an almost contact metric manifold the NGT with torsion spaces are characterized and a possibly new class of almost contact metric manifolds is extracted. Similar considerations lead to a definition of a particular classes of almost para-Hermitian and almost paracontact metric manifolds. The conditions are given in terms of the corresponding Nijenhuis tensors and the exterior derivative of the skew-symmetric part of the non-symmetric Riemannian metric.
Towards a double field theory on para-Hermitian manifolds
Vaisman, Izu [Department of Mathematics, University of Haifa, Haifa (Israel)] [Department of Mathematics, University of Haifa, Haifa (Israel)
2013-12-15T23:59:59.000Z
In a previous paper, we have shown that the geometry of double field theory has a natural interpretation on flat para-Kähler manifolds. In this paper, we show that the same geometric constructions can be made on any para-Hermitian manifold. The field is interpreted as a compatible (pseudo-)Riemannian metric. The tangent bundle of the manifold has a natural, metric-compatible bracket that extends the C-bracket of double field theory. In the para-Kähler case, this bracket is equal to the sum of the Courant brackets of the two Lagrangian foliations of the manifold. Then, we define a canonical connection and an action of the field that correspond to similar objects of double field theory. Another section is devoted to the Marsden-Weinstein reduction in double field theory on para-Hermitian manifolds. Finally, we give examples of fields on some well-known para-Hermitian manifolds.
The Yamabe equation on complete manifolds with finite volume
Große, Nadine
2011-01-01T23:59:59.000Z
We prove the existence of a solution of the Yamabe equation on complete manifolds with finite volume and positive Yamabe invariant. In order to circumvent the standard methods on closed manifolds which heavily rely on global (compact) Sobolev embeddings we approximate the solution by eigenfunctions of certain conformal complete metrics. This also gives rise to a new proof of the well-known result for closed manifolds and positive Yamabe invariant.
The genus spectrum of a hyperbolic 3-manifold
McReynolds, D B
2009-01-01T23:59:59.000Z
In this article we study the spectrum of totally geodesic surfaces of a finite volume hyperbolic 3-manifold. We show that for arithmetic hyperbolic 3-manifolds that contain a totally geodesic surface, this spectrum determines the commensurability class. In addition, we show that any finite volume hyperbolic 3-manifold has many pairs of non-isometric finite covers with identical spectra. Forgetting multiplicities, we can also construct pairs where the volume ratio is unbounded.
Nonrelativistic hydrogen type stability problems on nonparabolic 3-manifolds
Batu Güneysu
2012-03-19T23:59:59.000Z
We extend classical Euclidean stability theorems corresponding to the nonrelativistic Hamiltonians of ions with one electron to the setting of non parabolic Riemannian 3-manifolds.
D-branes on group manifolds and fusion rings
P. Bouwknegt; P. Dawson; D. Ridout
2002-10-31T23:59:59.000Z
In this paper we compute the charge group for symmetry preserving D-branes on group manifolds for all simple, simply-connected, connected compact Lie groups G.
Engine Air Intake Manifold Having Built In Intercooler
Freese, V, Charles E. (Westland, MI)
2000-09-12T23:59:59.000Z
A turbocharged V type engine can be equipped with an exhaust gas recirculation cooler integrated into the intake manifold, so as to achieve efficiency, cost reductions and space economization improvements. The cooler can take the form of a tube-shell heat exchanger that utilizes a cylindrical chamber in the air intake manifold as the heat exchanger housing. The intake manifold depends into the central space formed by the two banks of cylinders on the V type engine, such that the central space is effectively utilized for containing the manifold and cooler.
audio localization manifold: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Algorithm Computer Technologies and Information Sciences Websites Summary: for LTSA in a special case. 1 Introduction Manifold learning (ML) methods have attracted...
Mathematical definition of quantum field theory on a manifold
A. V. Stoyanovsky
2009-11-21T23:59:59.000Z
We give a mathematical definition of quantum field theory on a manifold, and definition of quantization of a classical field theory given by a variational principle.
Dispersion strengthened copper
Sheinberg, H.; Meek, T.T.; Blake, R.D.
1990-01-09T23:59:59.000Z
A composition of matter is described which is comprised of copper and particles which are dispersed throughout the copper, where the particles are comprised of copper oxide and copper having a coating of copper oxide. A method for making this composition of matter is also described. This invention relates to the art of powder metallurgy and, more particularly, it relates to dispersion strengthened metals.
Optical manifold for light-emitting diodes
Chaves, Julio C.; Falicoff, Waqidi; Minano, Juan C.; Benitez, Pablo; Parkyn Jr., William A.; Alvarez, Roberto; Dross, Oliver
2008-06-03T23:59:59.000Z
An optical manifold for efficiently combining a plurality of blue LED outputs to illuminate a phosphor for a single, substantially homogeneous output, in a small, cost-effective package. Embodiments are disclosed that use a single or multiple LEDs and a remote phosphor, and an intermediate wavelength-selective filter arranged so that backscattered photoluminescence is recycled to boost the luminance and flux of the output aperture. A further aperture mask is used to boost phosphor luminance with only modest loss of luminosity. Alternative non-recycling embodiments provide blue and yellow light in collimated beams, either separately or combined into white.
On the effect of perforated plates on the acoustics of annular combustors
Paris-Sud XI, Université de
On the effect of perforated plates on the acoustics of annular combustors E. Gullaud1 CERFACS], acoustic Helmholtz solvers can prove to be sufficient to compute the thermoacoustic modes of a combustor accuracy of these computations, the whole complex geometry of the combustor, including the combustion
On the effect of perforated plates on the acoustics of annular combustors
Nicoud, Franck
On the effect of perforated plates on the acoustics of annular combustors E. Gullaud1 CERFACS [9, 10], the thermoacoustic modes of a combustor can be computed more 3 #12;efficiently by using to account for the complex geometry of the combustor, including the combustion chamber, casing, swirlers
A construction of a nonparametric quantum information manifold
Anna Jencova
2005-11-21T23:59:59.000Z
We present a construction of a Banach manifold on the set of faithful normal states of a von Neumann algebra, where the underlying Banach space is a quantum analogue of an Orlicz space. On the manifold, we introduce the exponential and mixture connections as dual pair of affine connections.
Manifold to uniformly distribute a solid-liquid slurry
Kern, Kenneth C. (Lake Hiawatha, NJ)
1983-01-01T23:59:59.000Z
This invention features a manifold that divides a stream of coal particles and liquid into several smaller streams maintaining equal or nearly equal mass compositions. The manifold consists of a horizontal, variable area header having sharp-edged, right-angled take-offs which are oriented on the bottom of the header.
Einstein manifolds with convex boundaries JeanMarc Schlenker \\Lambda
Schlenker, Jean-Marc
Einstein manifolds with convex boundaries JeanÂMarc Schlenker \\Lambda February 2, 1999 Abstract Let (M; @M) be a compact m+1Âmanifold with boundary with an Einstein metric g 0 , with ric g0 = \\Gammamg metric on @M . Then any metric close enough to h 0 is induced on @M by an Einstein metric g with ric g
Einstein manifolds with convex boundaries Jean-Marc Schlenker*
Schlenker, Jean-Marc
Einstein manifolds with convex boundaries Jean Let (M, @M) be a compact m+1-manifold with boundary with an Einstein me* *tric g0, with ricg0 be the induced metric on @M. Then any metric close e* *nough to h0 is induced on @M by an Einstein metric g
EMBEDDINGS IN GENERALIZED MANIFOLDS J. L. BRYANT AND W. MIO
Mio, Washington
EMBEDDINGS IN GENERALIZED MANIFOLDS J. L. BRYANT AND W. MIO Abstract. We prove that a (2m \\Gamma n supported by NSF grant DMSÂ9626624. 1 #12; 2 J. L. BRYANT AND W. MIO specifically, we establish analoguesÂmanifold with the DDP , n â?? 5, could be approximated by embeddings [5]. Bryant [2] and Walsh [20] were able to establish
EMBEDDINGS IN GENERALIZED MANIFOLDS J. L. BRYANT AND W. MIO
Mio, Washington
EMBEDDINGS IN GENERALIZED MANIFOLDS J. L. BRYANT AND W. MIO Abstract. We prove that a 2m,n+1 manifolds,embeddings. Partially supported by NSF grant DMS-9626624. 1 #12;2 J. L. BRYANT AND W. MIO speci . Bryant 2 and Walsh 20 were able to establish general position theorems for maps of arbitrary polyhedra
G 2 MANIFOLDS WITH PARALLEL CHARACTERISTIC TORSION THOMAS FRIEDRICH
Friedrich, Thomas
these spaces admit a metric connec tion # c with totally skewsymmetric torsion and a spinor field #1 solvingG 2 MANIFOLDS WITH PARALLEL CHARACTERISTIC TORSION THOMAS FRIEDRICH Abstract. We classify 7dimensional cocalibrated G2manifolds with parallel char acteristic torsion and nonabelian holonomy. All
Interference evaluation between manifold and wet Christmas tree CP systems
Brasil, S.L.D.C.; Baptista, W.
2000-05-01T23:59:59.000Z
Offshore production wells are controlled by valves installed in the marine soil, called wet Christmas trees (WCTs). A manifold receives the production of several wells and transports it to the platform. The manifold is cathodically protected by Al anodes and the WCT by Zn anodes. A computer simulation was carried out to evaluate the interference between the equipment cathodic protection systems.
ASYMPTOTIC PROPERTIES OF THE HEAT KERNEL ON CONIC MANIFOLDS
Loya, Paul
ASYMPTOTIC PROPERTIES OF THE HEAT KERNEL ON CONIC MANIFOLDS PAUL LOYA Abstract. We derive Foundation Fellowship. 1 #12; 2 PAUL LOYA Trace expansions of cone operators has a long history stemming from on conic manifolds; see for instance, Callias [5], Cheeger [7], Chou [9], BrË?uning--Seeley [3], Br
Rough Solutions of the Einstein Constraints on Closed Manifolds without Near-CMC Conditions
Holst, Michael; Nagy, Gabriel; Tsogtgerel, Gantumur
2009-01-01T23:59:59.000Z
global) sub- and super-solution constructions for closed manifolds; analogous constructions for compactof compact manifolds with boundary. Lemma 7 (Global super-
Instantons on sine-cones over Sasakian manifolds
Severin Bunk; Tatiana A. Ivanova; Olaf Lechtenfeld; Alexander D. Popov; Marcus Sperling
2014-07-10T23:59:59.000Z
We investigate instantons on sine-cones over Sasaki-Einstein and 3-Sasakian manifolds. It is shown that these conical Einstein manifolds are K"ahler with torsion (KT) manifolds admitting Hermitian connections with totally antisymmetric torsion. Furthermore, a deformation of the metric on the sine-cone over 3-Sasakian manifolds allows one to introduce a hyper-K"ahler with torsion (HKT) structure. In the large-volume limit these KT and HKT spaces become Calabi-Yau and hyper-K"ahler conifolds, respectively. We construct gauge connections on complex vector bundles over conical KT and HKT manifolds which solve the instanton equations for Yang-Mills fields in higher dimensions.
Dual manifold system and method for fluid transfer
Doktycz, Mitchel J. (Knoxville, TN); Bryan, William Louis (Knoxville, TN); Kress, Reid (Oak Ridge, TN)
2003-05-27T23:59:59.000Z
A dual-manifold assembly is provided for the rapid, parallel transfer of liquid reagents from a microtiter plate to a solid state microelectronic device having biological sensors integrated thereon. The assembly includes aspiration and dispense manifolds connected by a plurality of conduits. In operation, the aspiration manifold is actuated such that the aspiration manifold is seated onto an array of reagent-filled wells of the microtiter plate. The wells are pressurized to force reagent through conduits toward the dispense manifold. A pressure pulse provided by a standard ink-jet printhead ejects nanoliter-to-picoliter droplets of reagent through an array of printhead orifices and onto test sites on the surface of the microelectronic device.
Dual manifold system and method for fluid transfer
Doktycz, Mitchel J.; Bryan, William Louis; Kress, Reid
2003-09-30T23:59:59.000Z
A dual-manifold assembly is provided for the rapid, parallel transfer of liquid reagents from a microtiter plate to a solid state microelectronic device having biological sensors integrated thereon. The assembly includes aspiration and dispense manifolds connected by a plurality of conduits. In operation, the aspiration manifold is actuated such that the aspiration manifold is seated onto an array of reagent-filled wells of the microtiter plate. The wells are pressurized to force reagent through conduits toward the dispense manifold. A pressure pulse provided by a standard ink-jet printhead ejects nanoliter-to-picoliter droplets of reagent through an array of printhead orifices and onto test sites on the surface of the microelectronic device.
Dranchenko, B.N.; Portnov, B.B.; Seleznev, A.V.; Danilova, T.N.; Komarova, S.N.; Ponomareva, V.K.
1994-06-01T23:59:59.000Z
Cylindrical shells with regular perforation are widely used in power generating equipment and in particular in collectors 1 of the circuit of steam generators of power generating installations with water-water reactors (WWPR) The state of stress of collectors is determined by a broad spectrum of technological and operational loads, it is therefore difficult to analyze it theoretically. The aim of the present work is the experimental investigation of stresses in the cylindrical shells of collectors subjected to internal pressure, the generalization and systematization of empirical data in the form of engineering formulas and nomographs. The investigations were carried out with photoelastic three-dimensional models with the use of {open_quotes}freezing{close_quotes}. The basic characteristics of the state of stress of perforated shells (in particular those used in calculations of the strength and life of collectors) are the values of the stress intensity factor K and of the stress intensification factor {gamma}{sub {bar {sigma}}}{sub me} of the mean integral stress level in the neck between neighboring holes. The presented data make it possible to establish quantitatively the regularities of change of K and {gamma}{sub {bar {sigma}}}{sub me} in dependence on the geometry of the perforated shells. These data were systematized according to a special program of multifactor regression analysis. It follows from the presented formulas and nomographs in particular that in the ranges of the geometry of the perforated shells K may change from 2.5 to 4.0, and {gamma}{sub {bar {sigma}}}{sub me} from 1.1 to 2.3. Therefore varied geometric parameters have a substantial effect on the load intensity of perforated shells, and that once again confirms how topical it is to obtain new experimental data, to generalize and systematize them.
Yoder, Graydon L.
1980-01-01T23:59:59.000Z
Dispersed flow consists of small liquid droplets entrained in a flowing vapor. This flow regime can occur in cryogenic equipment, in steam generators, and during nuclear reactor loss of coolant accidents. A theoretical ...
Manifold corrections on spinning compact binaries
Zhong Shuangying; Wu Xin [Nanchang University, Nanchang 330031 (China)
2010-05-15T23:59:59.000Z
This paper deals mainly with a discussion of three new manifold correction methods and three existing ones, which can numerically preserve or correct all integrals in the conservative post-Newtonian Hamiltonian formulation of spinning compact binaries. Two of them are listed here. One is a new momentum-position scaling scheme for complete consistency of both the total energy and the magnitude of the total angular momentum, and the other is the Nacozy's approach with least-squares correction of the four integrals including the total energy and the total angular momentum vector. The post-Newtonian contributions, the spin effects, and the classification of orbits play an important role in the effectiveness of these six manifold corrections. They are all nearly equivalent to correct the integrals at the level of the machine epsilon for the pure Kepler problem. Once the third-order post-Newtonian contributions are added to the pure orbital part, three of these corrections have only minor effects on controlling the errors of these integrals. When the spin effects are also included, the effectiveness of the Nacozy's approach becomes further weakened, and even gets useless for the chaotic case. In all cases tested, the new momentum-position scaling scheme always shows the optimal performance. It requires a little but not much expensive additional computational cost when the spin effects exist and several time-saving techniques are used. As an interesting case, the efficiency of the correction to chaotic eccentric orbits is generally better than one to quasicircular regular orbits. Besides this, the corrected fast Lyapunov indicators and Lyapunov exponents of chaotic eccentric orbits are large as compared with the uncorrected counterparts. The amplification is a true expression of the original dynamical behavior. With the aid of both the manifold correction added to a certain low-order integration algorithm as a fast and high-precision device and the fast Lyapunov indicators of two nearby trajectories, phase space scans for chaos in the spinning compact binary system are given.
Geometric solitons of Hamiltonian flows on manifolds
Song, Chong, E-mail: songchong@xmu.edu.cn [School of Mathematical Sciences, Xiamen University, Xiamen 361005 (China)] [School of Mathematical Sciences, Xiamen University, Xiamen 361005 (China); Sun, Xiaowei, E-mail: sunxw@cufe.edu.cn [School of Applied Mathematics, Central University of Finance and Economics, Beijing 100081 (China)] [School of Applied Mathematics, Central University of Finance and Economics, Beijing 100081 (China); Wang, Youde, E-mail: wyd@math.ac.cn [Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing 100190 (China)] [Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing 100190 (China)
2013-12-15T23:59:59.000Z
It is well-known that the LIE (Locally Induction Equation) admit soliton-type solutions and same soliton solutions arise from different and apparently irrelevant physical models. By comparing the solitons of LIE and Killing magnetic geodesics, we observe that these solitons are essentially decided by two families of isometries of the domain and the target space, respectively. With this insight, we propose the new concept of geometric solitons of Hamiltonian flows on manifolds, such as geometric Schrödinger flows and KdV flows for maps. Moreover, we give several examples of geometric solitons of the Schrödinger flow and geometric KdV flow, including magnetic curves as geometric Schrödinger solitons and explicit geometric KdV solitons on surfaces of revolution.
Acharya, Jyotsna, E-mail: jyoacharya@yahoo.com; Bancroft, Karen; Lay, James [Royal Bolton Hospital (United Kingdom)
2012-12-15T23:59:59.000Z
We report a case of a 43-year-old woman who underwent uterine artery embolization (UAE) for a symptomatic large fibroid uterus and had spontaneous perforation of the transverse colon 3 months after embolisation with near-fatal consequences. We believe this is the first reported case in the literature of this serious complication of UAE. We briefly review the literature on bowel complications after UAE and discuss lessons to be learned regarding patient selection and postprocedure follow-up.
Computation of Slow Invariant Manifolds for Hydrogen-Air Systems
· Summary #12;Introduction Motivation and background · Detailed kinetics are essential for accurate modeling systems · ILDM, CSP, and ICE-PIC are approximations of the reaction slow invariant manifold. · MEPT
Fixed points, stable manifolds, weather regimes, and their predictability
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Deremble, Bruno; D'Andrea, Fabio; Ghil, Michael
2009-01-01T23:59:59.000Z
In a simple, one-layer atmospheric model, we study the links between low-frequency variability and the model’s fixed points in phase space. The model dynamics is characterized by the coexistence of multiple ''weather regimes.'' To investigate the transitions from one regime to another, we focus on the identification of stable manifolds associated with fixed points. We show that these manifolds act as separatrices between regimes. We track each manifold by making use of two local predictability measures arising from the meteorological applications of nonlinear dynamics, namely, ''bred vectors'' and singular vectors. These results are then verified in the framework of ensemblemore »forecasts issued from clouds (ensembles) of initial states. The divergence of the trajectories allows us to establish the connections between zones of low predictability, the geometry of the stable manifolds, and transitions between regimes.« less
Fixed points, stable manifolds, weather regimes, and their predictability
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Deremble, Bruno [Laboratoire de Meteorologie Dynamique (CNRS and IPSL), Paris (France); D'Andrea, Fabio [Laboratoire de Meteorologie Dynamique (CNRS and IPSL), Paris (France); Ghil, Michael [Univ. of California, Los Angeles, CA (United Staes). Atmospheric and Oceanic Sciences and Inst. of Geophysics and Planetary Physics
2009-01-01T23:59:59.000Z
In a simple, one-layer atmospheric model, we study the links between low-frequency variability and the model’s fixed points in phase space. The model dynamics is characterized by the coexistence of multiple ''weather regimes.'' To investigate the transitions from one regime to another, we focus on the identification of stable manifolds associated with fixed points. We show that these manifolds act as separatrices between regimes. We track each manifold by making use of two local predictability measures arising from the meteorological applications of nonlinear dynamics, namely, ''bred vectors'' and singular vectors. These results are then verified in the framework of ensemble forecasts issued from clouds (ensembles) of initial states. The divergence of the trajectories allows us to establish the connections between zones of low predictability, the geometry of the stable manifolds, and transitions between regimes.
GEOMETRY OF KAHLER MANIFOLDS AND THE HODGE LAPLACIAN ON MINIMAL
Boyer, Edmond
of a spin manifold M to a spin submanifold is a Hermitian bun- dle given by the tensorial product the intrinsic spin bun- dle of the hypersurface and the induced Dirac operator is the intrinsic classical Dirac
SPLITTING MANIFOLD APPROXIMATE FIBRATIONS J. L. BRYANT AND P. KIRBY
Aluffi, Paolo
SPLITTING MANIFOLD APPROXIMATE FIBRATIONS J. L. BRYANT AND P. KIRBY Abstract. Suppose M, embeddings. Partially supported by NSF grant DMS-9626624. 1 #12; 2 J. L. BRYANT AND P. KIRBY 2. Definitions
Learning manifolds with k-means and k-flats
Canas, Guillermo D.
We study the problem of estimating a manifold from random samples. In particular, we consider piecewise constant and piecewise linear estimators induced by k-means and k-?ats, and analyze their performance. We extend ...
Classification of Certain Compact Riemannian Manifolds with Harmonic Curvature a...
Derdzinski, Andrzej
Classification of Certain Compact Riemannian Manifolds with Harmonic Curvature a... Derdzinski and University Library provides access to digitized documents strictly for noncommercial educational, research) requires prior written permission from the Goettingen State- and University Library. Each copy of any part
HARMONIC MAPPINGS BETWEEN RIEMANNIAN MANIFOLDS Anand Arvind Joshi
Leahy, Richard M.
HARMONIC MAPPINGS BETWEEN RIEMANNIAN MANIFOLDS by Anand Arvind Joshi A Thesis Presented ii Abstract iv 1 Harmonic Mappings 1 1.1 Space of Maps Variation Formula . . . . . . . . . . . . . . . . . . . . . . . . 11 1.4 Harmonic Maps
Instantons on the exceptional holonomy manifolds of Bryant and Salamon
Andrew Clarke
2014-04-15T23:59:59.000Z
We give a construction of $G_2$ and $Spin(7)$ instantons on exceptional holonomy manifolds constructed by Bryant and Salamon, by using an ansatz of spherical symmetry coming from the manifolds being the total spaces of rank-4 vector bundles. In the $G_2$ case, we show that, in the asymptotically conical model, the connections are asymptotic to Hermitian Yang-Mills connections on the nearly K\\"ahler $S^3\\times S^3$.
Covariant Star Product for Exterior Differential Forms on Symplectic Manifolds
McCurdy, Shannon; Zumino, Bruno [Physics Department, University of California, Berkeley, CA 94720-7300 (United States); Theoretical Physics Group, Lawrence Berkeley Laboratory, Berkeley, CA 947208162 (United States)
2010-02-10T23:59:59.000Z
After a brief description of the Z-graded differential Poisson algebra, we introduce a covariant star product for exterior differential forms and give an explicit expression for it up to second order in the deformation parameter h, in the case of symplectic manifolds. The graded differential Poisson algebra endows the manifold with a connection, not necessarily torsion-free, and places upon the connection various constraints.
Thermorheological properties of nanostructured dispersions
Gordon, Jeremy B
2007-01-01T23:59:59.000Z
Nanostructured dispersions, which consist of nanometer-sized particles, tubes, sheets, or droplets that are dispersed in liquids, have exhibited substantially higher thermal conductivities over those of the liquids alone. ...
Dispersive analysis of ?/? ? 3?, ??*
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Danilkin, Igor V.; Fernandez Ramirez, Cesar; Guo, Peng; Mathieu, Vincent; Schott, Diane M.; Shi, Meng; Szczepaniak, Adam P.
2015-05-01T23:59:59.000Z
The decays ?/? ? 3? are considered in the dispersive framework that is based on the isobar decomposition and subenergy unitarity. The inelastic contributions are parametrized by the power series in a suitably chosen conformal variable that properly accounts for the analytic properties of the amplitude. The Dalitz plot distributions and integrated decay widths are presented. Our results indicate that the final- state interactions may be sizable. As a further application of the formalism we also compute the electromagnetic transition form factors of ?/? ? ???*.
Nozzle for electric dispersion reactor
Sisson, W.G.; Harris, M.T.; Scott, T.C.; Basaran, O.A.
1996-04-02T23:59:59.000Z
A nozzle for an electric dispersion reactor includes two coaxial cylindrical bodies, the inner one of the two delivering disperse phase fluid into a continuous phase fluid. A potential difference generated by a voltage source creates a dispersing electric field at the end of the inner electrode. 5 figs.
Nozzle for electric dispersion reactor
Sisson, Warren G. (Oak Ridge, TN); Basaran, Osman A. (Oak Ridge, TN); Harris, Michael T. (Knoxville, TN)
1995-01-01T23:59:59.000Z
A nozzle for an electric dispersion reactor includes two concentric electrodes, the inner one of the two delivering disperse phase fluid into a continuous phase fluid. A potential difference generated by a voltage source creates a dispersing electric field at the end of the inner electrode.
Nozzle for electric dispersion reactor
Sisson, Warren G. (Oak Ridge, TN); Harris, Michael T. (Knoxville, TN); Scott, Timothy C. (Knoxville, TN); Basaran, Osman A. (Oak Ridge, TN)
1998-01-01T23:59:59.000Z
A nozzle for an electric dispersion reactor includes two coaxial cylindrical bodies, the inner one of the two delivering disperse phase fluid into a continuous phase fluid. A potential difference generated by a voltage source creates a dispersing electric field at the end of the inner electrode.
Nozzle for electric dispersion reactor
Sisson, Warren G. (Oak Ridge, TN); Basaran, Osman A. (Oak Ridge, TN); Harris, Michael T. (Knoxville, TN)
1998-01-01T23:59:59.000Z
A nozzle for an electric dispersion reactor includes two concentric electrodes, the inner one of the two delivering disperse phase fluid into a continuous phase fluid. A potential difference generated by a voltage source creates a dispersing electric field at the end of the inner electrode.
Nozzle for electric dispersion reactor
Sisson, Warren G. (Oak Ridge, TN); Harris, Michael T. (Knoxville, TN); Scott, Timothy C. (Knoxville, TN); Basaran, Osman A. (Oak Ridge, TN)
1996-01-01T23:59:59.000Z
A nozzle for an electric dispersion reactor includes two coaxial cylindrical bodies, the inner one of the two delivering disperse phase fluid into a continuous phase fluid. A potential difference generated by a voltage source creates a dispersing electric field at the end of the inner electrode.
Nozzle for electric dispersion reactor
Sisson, W.G.; Harris, M.T.; Scott, T.C.; Basaran, O.A.
1998-06-02T23:59:59.000Z
A nozzle for an electric dispersion reactor includes two coaxial cylindrical bodies, the inner one of the two delivering disperse phase fluid into a continuous phase fluid. A potential difference generated by a voltage source creates a dispersing electric field at the end of the inner electrode. 5 figs.
Nozzle for electric dispersion reactor
Sisson, W.G.; Basaran, O.A.; Harris, M.T.
1998-04-14T23:59:59.000Z
A nozzle for an electric dispersion reactor includes two concentric electrodes, the inner one of the two delivering disperse phase fluid into a continuous phase fluid. A potential difference generated by a voltage source creates a dispersing electric field at the end of the inner electrode. 4 figs.
L. A. Falkovsky
2007-08-11T23:59:59.000Z
Taking into account the constraints imposed by the lattice symmetry, the phonon dispersion is calculated for graphene with interactions between the first and second nearest neighbors in the framework of the Born-von Karman model. Analytical expressions are obtained for the out-of-plane (bending) modes determined only by two force constants as well as for the in-plane modes with four force constants. Values of the force constants are found in fitting to elastic constants and Raman frequencies observed in graphite.
Office of Environmental Management (EM)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33 1112011AT&T,Office of Policy,Policy ActDetroit EdisonCity, Arizona, SiteDiscussionDispersion
Distributed mean curvature on a discrete manifold for Regge calculus
Rory Conboye; Warner A. Miller; Shannon Ray
2015-02-26T23:59:59.000Z
The integrated mean curvature of a simplicial manifold is well understood in both Regge Calculus and Discrete Differential Geometry. However, a well motivated pointwise definition of curvature requires a careful choice of volume over which to uniformly distribute the local integrated curvature. We show that hybrid cells formed using both the simplicial lattice and its circumcentric dual emerge as a remarkably natural structure for the distribution of this local integrated curvature. These hybrid cells form a complete tessellation of the simplicial manifold, contain a geometric orthonormal basis, and are also shown to give a pointwise mean curvature with a natural interpretation as a fractional rate of change of the normal vector.
Self-dual metrics on toric 4-manifolds: extending the Joyce construction
Griffiths, Hugh Norman
2009-01-01T23:59:59.000Z
Toric geometry studies manifolds M2n acted on effectively by a torus of half their dimension, Tn. Joyce shows that for such a 4-manifold sufficient conditions for a conformal class of metrics on the free part of the ...
First laboratory perforating tests in coal show lower-than-expected penetration
Snider, P.M.; Walton, I.C.; Skinner, T.K.; Atwood, D.C.; Grove, B.M.; Graham, C.
2008-06-15T23:59:59.000Z
Worldwide Coal Bed Methane (CBM) resources are huge, estimated at 3,000 to 9,000 Tcf. The production rate from CBM reservoirs is low, perhaps 50-100 mcf/day. Various completion methods are being evaluated and new technologies are being developed with the aim of increasing production rates. Considering this interest and activity level, little attention has been paid to the CBM completion fundamentals. Perforating is a critical part of this process, especially considering the PRB development migration from single-coal, open-hole completions into multi-zone, cased-hole completions. This paper describes the first known laboratory-testing program to investigate shaped charge penetration in coal targets. We describe mechanical properties of the coals tested, and penetration results for different shaped charges (of different designs), shot at various stress conditions. CT scan and cutaway imaging of the perforation tunnels are also discussed. Tests were conducted under dry and saturated conditions. The preliminary experiments reported here indicate that shaped charge penetration in coal is significantly less than expected, considering the target's density and strength. The authors provide insight into what may be the reasons for these unexpected results and recommend a path forward for shaped charge testing, designs, predictive tools, and how to optimize CBM completions.
ALMOST JET STRUCTURES AND FIRST JET-EXTENSIONS OF FIBRED MANIFOLDS
Pasquero, Stefano
ALMOST JET STRUCTURES AND FIRST JET-EXTENSIONS OF FIBRED MANIFOLDS Paola Morando Dipartimento di conditions for a manifold M to be diffeomorphic to the first jetextension j1(N) of a fibred manifold N O are given in terms of almost jet structures, i.e. pairs (S, A), where S is a suitable type (2, 1) tensor
White noise analysis on manifolds and the energy representation of a gauge group
Takahiro Hasebe
2011-01-15T23:59:59.000Z
The energy representation of a gauge group on a Riemannian manifold has been discussed by several authors. Y. Shimada has shown the irreducibility for compact Riemannian manifold, using white noise analysis. In this paper we extend its technique to noncompact Riemannian manifolds which have differential operators satisfying some conditions.
Environmental Pollution Air Pollution Dispersion Practical Air Pollution Dispersion
Moncrieff, John B.
Environmental Pollution Air Pollution Dispersion 1 of 5 Practical Â Air Pollution Dispersion in the lectures how such models can be used to explain observed concentrations of air pollutants in an area and to test `what-if' scenarios for pollution control and reduction. You will use the Gaussian Plume Model
Manifold Homotopy via the Flow Complex Bardia Sadri
Toronto, University of
modeling though much of the mathematical foundations behind the flow complex were well-explored priorManifold Homotopy via the Flow Complex Bardia Sadri Abstract It is known that the critical points versus those of deep critical points, in a filtration of the flow complex based on the distance
Clay Mathematics Proceedings Kahler-Ricci flow on complete manifolds
Ni, Lei
Clay Mathematics Proceedings K¨ahler-Ricci flow on complete manifolds Lei Ni Abstract. This is a paper based on author's lectures delivered at the 2005 Clay Mathematics Institute summer school at MSRI The 2005 Clay Mathematics Institute summer school at MSRI focused on Perel- man's work on Ricci flow
Geodesic Regression on Riemannian Manifolds P. Thomas Fletcher
Boyer, Edmond
- ing multiple linear regression in Rn . Here we are interested in the relationship between a non that one could choose, and it provides a direct generalization of linear regression to the manifold setting regression model is linear regression, due to its simplicity, ease of interpretation, and ability to model
An implicit trust-region method on Riemannian manifolds§
2007-06-06T23:59:59.000Z
Jun 6, 2007 ... described in terms of optimizing a smooth function on a manifold (e.g., the eigen- value problem .... Use CG recurrences to update residual and search direction. 21: Set rj+1 = rj .... only once and never re-enter it. However, for ...
nlin.PS/0201047 Unstable manifolds and Schrodinger dynamics
Schroers, Bernd J.
, United Kingdom January 2002 Abstract The time evolution of several interacting Ginzburg-Landau vortices to the unit circle in C . It therefore has an associated integer winding number or degree, which can of the Ginzburg-Landau energy functional. For two vortices the relevant un- stable manifold is constructed
Protein clustering on a Grassmann manifold Chendra Hadi Suryanto1
Fukui, Kazuhiro
of the protein. The similarity of two protein structures is then defined by the canonical angles between outperforms the k-means clustering with Gauss Integrals Tuned, which is a state-of- the-art descriptor manifold, Gauss Integrals 1 Introduction Since there are numerous proteins whose functions are yet
university-logo Complete affine 3-manifolds and hyperbolic
Goldman, William
university-logo Complete affine 3-manifolds and hyperbolic surfaces Dedicated to Bill Thurston and hyperbolic surfaces #12;university-logo Three-dimensional affine space forms When can a group G act;university-logo Three-dimensional affine space forms When can a group G act on Euclidean space with quotient
Fermion dispersion in axion medium
N. V. Mikheev; E. N. Narynskaya
2008-12-02T23:59:59.000Z
The interaction of a fermion with the dense axion medium is investigated for the purpose of finding an axion medium effect on the fermion dispersion. It is shown that axion medium influence on the fermion dispersion under astrophysical conditions is negligible small if the correct Lagrangian of the axion-fermion interaction is used.
Shultis, J. Kenneth
be realized for doubled or "sand- wiched" devices. Index Terms--Perforated detector, semiconductor neutron de neutron detection by a variety of re- search groups [1][14], all of which have generally used B, Li, Li 66506 USA (e-mail: mc- gregor@ksu.edu). Digital Object Identifier 10.1109/TNS.2006.872639 enter
Paris-Sud XI, Université de
on the transformation kinetics of TRIP and dual phase steels has been analyzed by many researchers, for example Al are responsible for the deformation pro cess taking place in TRIP steels during and after the phase transforThermo-mechanical behaviour of TRIP 1000 steel sheets subjected to low velocity perforation
Peirce, Anthony
Simultaneous Growth of Multiple Hydraulic Fractures A.P. Peirce, University of British Columbia and A.P. Bunger in horizontal well stimulation is the generation of hydraulic fractures (HFs) from all perforation clusters shadowing" that refers to suppression of some hydraulic fractures by the compressive stresses exerted
Vladimir Maz'ya; Alexander Movchan; Michael Nieves
2010-05-24T23:59:59.000Z
We describe a method of asymptotic approximations to solutions of mixed boundary value problems for the Laplacian in a three-dimensional domain with many perforations of arbitrary shape, with the Neumann boundary conditions being prescribed on the surfaces of small voids. The only assumption made on the geometry is that the diameter of a void is assumed to be smaller compared to the distance to the nearest neighbour. The asymptotic approximation, obtained here, involves a linear combination of dipole fields constructed for individual voids, with the coefficients, which are determined by solving a linear algebraic system. We prove the solvability of this system and derive an estimate for its solution. The energy estimate is obtained for the remainder term of the asymptotic approximation.
Modeling volcanic ash dispersal
None
2011-10-06T23:59:59.000Z
Explosive volcanic eruptions inject into the atmosphere large amounts of volcanic material (ash, blocks and lapilli). Blocks and larger lapilli follow ballistic and non-ballistic trajectories and fall rapidly close to the volcano. In contrast, very fine ashes can remain entrapped in the atmosphere for months to years, and may affect the global climate in the case of large eruptions. Particles having sizes between these two end-members remain airborne from hours to days and can cover wide areas downwind. Such volcanic fallout entails a serious threat to aircraft safety and can create many undesirable effects to the communities located around the volcano. The assessment of volcanic fallout hazard is an important scientific, economic, and political issue, especially in densely populated areas. From a scientific point of view, considerable progress has been made during the last two decades through the use of increasingly powerful computational models and capabilities. Nowadays, models are used to quantify hazard scenarios and/or to give short-term forecasts during emergency situations. This talk will be focused on the main aspects related to modeling volcanic ash dispersal and fallout with application to the well known problem created by the Eyjafjöll volcano in Iceland. Moreover, a short description of the main volcanic monitoring techniques is presented.
Determination of dispersivities from a natural-gradient dispersion test
Hoover, Caroline Marie
1985-01-01T23:59:59.000Z
of H drolo can be valuable predictive tool s (Wang and Anderson, 1982). Since the late 1800's, mathematical models have been used in problems of groundwater flow. Their appl ication now extends to problems of contaminant transport and migration...DETERMINATION OF DISPERSIVITIES FROM A NATURAL-GRADIENT DISPERSION TEST A Thesis by CAROLINE MARIE HOOVER Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirements for the degree of MASTER...
Velocity Dispersions Across Bulge Types
Fabricius, Maximilian; Bender, Ralf; Hopp, Ulrich [University Observatory of the Ludwig-Maximilians University (LMU) (Germany); Max-Planck Institute for Extraterrestrial Physics (MPE) (Germany); Saglia, Roberto; Drory, Niv [Max-Planck Institute for Extraterrestrial Physics (MPE) (Germany); Fisher, David [Department of Astronomy, University of Texas at Austin (United States)
2010-06-08T23:59:59.000Z
We present first results from a long-slit spectroscopic survey of bulge kinematics in local spiral galaxies. Our optical spectra were obtained at the Hobby-Eberly Telescope with the LRS spectrograph and have a velocity resolution of 45 km/s (sigma*), which allows us to resolve the velocity dispersions in the bulge regions of most objects in our sample. We find that the velocity dispersion profiles in morphological classical bulge galaxies are always centrally peaked while the velocity dispersion of morphologically disk-like bulges stays relatively flat towards the center--once strongly barred galaxies are discarded.
Almost Einstein and Poincare-Einstein manifolds in Riemannian signature
A. Rod Gover
2008-03-25T23:59:59.000Z
An almost Einstein manifold satisfies equations which are a slight weakening of the Einstein equations; Einstein metrics, Poincare-Einstein metrics, and compactifications of certain Ricci-flat asymptotically locally Euclidean structures are special cases. The governing equation is a conformally invariant overdetermined PDE on a function. Away from the zeros of this the almost Einstein structure is Einstein, while the zero set gives a scale singularity set which may be viewed as a conformal infinity for the Einstein metric. In this article we give a classification of the possible scale singularity spaces and derive geometric results which explicitly relate the intrinsic conformal geometry of these to the conformal structure of the ambient almost Einstein manifold. Classes of examples are constructed. A compatible generalisation of the constant scalar curvature condition is also developed. This includes almost Einstein as a special case, and when its curvature is suitably negative, is closely linked to the notion of an asymptotically hyperbolic structure.
Fuel cell stack with internal manifolds for reactant gases
Schnacke, Arthur W. (Schenectady, NY)
1985-01-01T23:59:59.000Z
A fuel cell stack includes a plurality of plate-like fuel cells arranged along an axis generally parallel to cell thickness with electrically conductive separator plates between each pair of cells. A plurality of axial manifolds are provided at opposite sides of the stack in outer marginal portions beyond the edges of electrodes and electrolyte tiles. Sealing rings prevent cross-leakage of oxidant fuel gases through use of pairs of outwardly extending lips from opposite tile surfaces bonded to first and second electrode frames respectively. The frames provide transition between electrode edges and manifold perimeters. The pairs of extension lips are sealingly bonded together through an electrically insulative sealing ring with wedge shaped fastening members.
Fuel cell stack with internal manifolds for reactant gases
Schnacke, A.W.
1983-10-12T23:59:59.000Z
A fuel cell stack includes a plurality of plate-like fuel cells arranged along an axis generally parallel to cell thickness with electrically conductive separator plates between each pair of cells. A plurality of axial manifolds are provided at opposite sides of the stack in outer marginal portions beyond the edges of electrodes and electrolyte tiles. Sealing rings prevent cross-leakage of oxidant fuel gases through use of pairs of outwardly extending lips from opposite tile surfaces bonded to first and second electrode frames respectively. The frames provide transition between electrode edges and manifold perimeters. The pairs of extension lips are sealingly bonded together through an electrically insulative sealing ring with wedge shaped fastening members.
Ohbuchi, Ryutarou
printers,... User generated. T i bl 3D h· Trimble 3D warehouse... 3D model retrieval is essential scanners, 3D printers,... User generated. T i bl 3D h· Trimble 3D warehouse... 3D model retrievalRanking on Cross Domain Manifold forRanking on Cross-Domain Manifold for Sketch-based 3D model
Ohbuchi, Ryutarou
printers,... User generated. T i bl 3D h· Trimble 3D warehouse... 3D model retrieval is essentialRanking on Cross Domain Manifold forRanking on Cross-Domain Manifold for Sketch-based 3D model Retrieval Takahiko FuruyaRyutarou Ohbuchi University of Yamanashi #12;IntroductionIntroduction 3D models
Heterogeneous Catalysis on Atomically Dispersed Supported Metals...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Catalysis on Atomically Dispersed Supported Metals: CO2 Reduction on Multifunctional Pd Catalysts. Heterogeneous Catalysis on Atomically Dispersed Supported Metals: CO2 Reduction...
Monopoles on the Bryant-Salamon $G_2$ Manifolds
Goncalo Oliveira
2014-11-06T23:59:59.000Z
$G_2$-Monopoles are solutions to gauge theoretical equations on noncompact $7$-manifolds of $G_2$ holonomy. We shall study this equation on the $3$ Bryant-Salamon manifolds. We construct examples of $G_2$-monopoles on two of these manifolds, namely the total space of the bundle of anti-self-dual two forms over the $\\mathbb{S}^4$ and $\\mathbb{CP}^2$. These are the first nontrivial examples of $G_2$-monopoles. Associated with each monopole there is a parameter $m \\in \\mathbb{R}^+$, known as the mass of the monopole. We prove that under a symmetry assumption, for each given $m \\in \\mathbb{R}^+$ there is a unique monopole with mass $m$. We also find explicit irreducible $G_2$-instantons on $\\Lambda^2_-(\\mathbb{S}^4)$ and on $\\Lambda^2_-(\\mathbb{CP}^2)$. The third Bryant-Salamon $G_2$-metric lives on the spinor bundle over the $3$-sphere. In this case we produce a vanishing theorem for monopoles.
Asphaltene dispersants as demulsification aids
Manek, M.B.
1995-11-01T23:59:59.000Z
Destabilization of petroleum asphaltenes may cause a multitude of problems in crude oil recovery and production. One major problem is their agglomeration at the water-oil interface of crude oil emulsions. Once agglomeration occurs, destabilized asphaltenes can form a thick pad in the dehydration equipment, which significantly reduces the demulsification rate. Certain polymeric dispersants increase asphaltene solubilization in hydrocarbon media, and when used in conjunction with emulsion breakers, facilitate the demulsification process. Two case studies are presented that demonstrate how asphaltene dispersants can efficiently inhibit pad formation and help reduce demulsifier dosage. Criteria for dispersant application and selection are discussed, which include the application of a novel laboratory technique to assess asphaltene stabilization in the crude oil. The technique monitors asphaltene agglomeration while undergoing titration with an incompatible solvent (precipitant). The method was used to evaluate stabilization of asphaltenes in the crude oil and to screen asphaltene dispersants.
Neutrino dispersion in magnetized plasma
N. V. Mikheev; E. N. Narynskaya
2008-12-02T23:59:59.000Z
The neutrino dispersion in the charge symmetric magnetized plasma is investigated. We have studied the plasma contribution into the additional energy of neutrino and obtained the simple expression for it. We consider in detail the neutrino self-energy under physical conditions of weak field, moderate field and strong field limits. It is shown that our result for neutrino dispersion in moderate magnetic field differ substantially from the previous one in the literature.
An upper bound for a Hilbert polynomial on quaternionic K"ahler manifolds
Weingart, Gregor
manifold (M, g) * *with holon- omy contained in Sp(1) . Sp(n). Associated with M is the twistor space Z
Quantum error correcting codes and 4-dimensional arithmetic hyperbolic manifolds
Guth, Larry, E-mail: lguth@math.mit.edu [Department of Mathematics, MIT, Cambridge, Massachusetts 02139 (United States); Lubotzky, Alexander, E-mail: alex.lubotzky@mail.huji.ac.il [Institute of Mathematics, Hebrew University, Jerusalem 91904 (Israel)
2014-08-15T23:59:59.000Z
Using 4-dimensional arithmetic hyperbolic manifolds, we construct some new homological quantum error correcting codes. They are low density parity check codes with linear rate and distance n{sup ?}. Their rate is evaluated via Euler characteristic arguments and their distance using Z{sub 2}-systolic geometry. This construction answers a question of Zémor [“On Cayley graphs, surface codes, and the limits of homological coding for quantum error correction,” in Proceedings of Second International Workshop on Coding and Cryptology (IWCC), Lecture Notes in Computer Science Vol. 5557 (2009), pp. 259–273], who asked whether homological codes with such parameters could exist at all.
The Bryant-Salamon G_2 manifolds and hypersurface geometry
Reiko Miyaoka
2006-06-02T23:59:59.000Z
We show that two of the Bryant-Salamon G_2-manifolds have a simple topology ; homeomorphic to the complement of some submanifolds of the 7-dimensional sphere. In this connection, we show there exists a complete Ricci-flat (non-flat) metric on the complement of an m-dimensional sphere in an n-dimensional sphere for some n-1>m. We also give many examples of special Lagrangian submanifolds of the cotangent bundle of the sphere with the Stenzel metric. Hypersurface geometry is essential in the argument.
Printed circuit dispersive transmission line
Ikezi, H.; Lin-Liu, Y.R.; DeGrassie, J.S.
1991-08-27T23:59:59.000Z
A printed circuit dispersive transmission line structure is disclosed comprising an insulator, a ground plane formed on one surface of the insulator, a first transmission line formed on a second surface of the insulator, and a second transmission line also formed on the second surface of the insulator and of longer length than the first transmission line and periodically intersecting the first transmission line. In a preferred embodiment, the transmission line structure exhibits highly dispersive characteristics by designing the length of one of the transmission line between two adjacent periodic intersections to be longer than the other. 5 figures.
Dispersion-compensated Fresnel lens
Johnson, K.C.
1992-11-03T23:59:59.000Z
A transmission grating is used to reduce chromatic aberration in a Fresnel lens, wherein the lens chromatic dispersion is offset and substantially canceled by the grating's diffraction-induced dispersion. The grating comprises a Fresnel-type pattern of microscopic facets molded directly into the lens surface. The facets would typically have a profile height of around 4[times]10[sup [minus]5] inch and a profile width of at least 10[sup [minus]3] inch. In its primary intended application, the invention would function to improve the optical performance of a Fresnel lens used to concentrate direct sunlight. 10 figs.
Dispersion-compensated fresnel lens
Johnson, Kenneth C. (1215 Brewster Dr., El Cerrito, CA 94530)
1992-01-01T23:59:59.000Z
A transmission grating is used to reduce chromatic aberration in a Fresnel lens, wherein the lens chromatic dispersion is offset and substantially canceled by the grating's diffraction-induced dispersion. The grating comprises a Fresnel-type pattern of microscopic facets molded directly into the lens surface. The facets would typically have a profile height of around 4.multidot.10.sup.-5 inch and a profile width of at least 10.sup.-3 inch. In its primary intended application, the invention would function to improve the optical performance of a Fresnel lens used to concentrate direct sunlight.
Convergence and Rate of Convergence of A Manifold-Based Dimension Reduction Algorithm
Zha, Hongyuan
of a local manifold learning algorithm: LTSA [13]. The main technical tool is the perturbation analysis some asymptotic properties of a local manifold learning algorithm: LTSA [13], as well as a demonstration of some of its limitations. The key idea in the analysis is to treat the solutions computed
DESINGULARIZING HOMOLOGY MANIFOLDS J. BRYANT, S. FERRY, W. MIO, AND S. WEINBERGER
Mio, Washington
DESINGULARIZING HOMOLOGY MANIFOLDS J. BRYANT, S. FERRY, W. MIO, AND S. WEINBERGER Abstract. We Date: August 24, 2005. Bryant and Mio were partially supported by NSF grants DMS-0071693 and DMS supported by NSF grant DMS-9803633. 1 #12;2 J. BRYANT, S. FERRY, W. MIO, AND S. WEINBERGER manifolds
THE CO-STABILITY MANIFOLD OF A TRIANGULATED CATEGORY PETER JRGENSEN AND DAVID PAUKSZTELLO
JÃ¸rgensen, Peter
THE CO-STABILITY MANIFOLD OF A TRIANGULATED CATEGORY PETER JÃ?RGENSEN AND DAVID PAUKSZTELLO Abstract co-stability conditions as a `continuous' generalisation of co-t-structures. Our main result is that the set of nice co-stability conditions on a triangulated category is a manifold. In particular, we show
THE FBI TRANSFORM ON COMPACT C 1 MANIFOLDS JARED WUNSCH AND MACIEJ ZWORSKI
Zworski, Maciej
THE FBI TRANSFORM ON COMPACT C 1 MANIFOLDS JARED WUNSCH AND MACIEJ ZWORSKI 1. Introduction In this paper we discuss the Fourier-Bros-Iagolnitzer (FBI) transform on smooth, boundaryless manifolds-compactness of the cotangent bundle. By reviewing the basic constructions of the FBI transform theory, we hope to make
Model building with intersecting D6-branes on smooth Calabi-Yau manifolds
Eran Palti
2009-02-20T23:59:59.000Z
We study intersecting D6-branes in Calabi-Yau manifolds that are smooth hypersurfaces in weighted projective spaces. We develop the techniques for calculating intersection numbers between special Lagrangian sub-manifolds defined as fixed loci of anti-holomorphic involutions. We present global Pati-Salam and MSSM-like models that are supersymmetric up to a decoupled hidden sector.
Study of Pollutant Dispersion in Urban Environments
Allen, Gabrielle
and Cell (MAC) method for the governing equations, transport of passive scalars like the pollutantStudy of Pollutant Dispersion in Urban Environments Razvan Corneliu Carbunescu Center head: Study of pollutant dispersion in urban environments #12;Abstract Computational simulations can
Dispersion enhanced metal/zeolite catalysts
Sachtler, W.M.H.; Tzou, M.S.; Jiang, H.J.
1987-03-31T23:59:59.000Z
Dispersion stabilized zeolite supported metal catalysts are provided as bimetallic catalyst combinations. The catalyst metal is in a reduced zero valent form while the dispersion stabilizer metal is in an unreduced ionic form. Representative catalysts are prepared from platinum or nickel as the catalyst metal and iron or chromium dispersion stabilizer.
Gravitational dispersion in a torsional wave machine
Rafael de la Madrid; Alejandro Gonzalez; George Irwin
2014-09-01T23:59:59.000Z
We demonstrate that mechanical waves traveling in a torsional, mechanical wave machine exhibit dispersion due to gravity and the discreteness of the medium. We also show that although the dispersion due to discreteness is negligible, the dispersion due to gravity can be easily measured, and can be shown to disappear in a zero-gravity environment.
Resolvent estimates and local decay of waves on conic manifolds
Dean Baskin; Jared Wunsch
2012-10-01T23:59:59.000Z
We consider manifolds with conic singularites that are isometric to $\\mathbb{R}^{n}$ outside a compact set. Under natural geometric assumptions on the cone points, we prove the existence of a logarithmic resonance-free region for the cut-off resolvent. The estimate also applies to the exterior domains of non-trapping polygons via a doubling process. The proof of the resolvent estimate relies on the propagation of singularities theorems of Melrose and the second author to establish a "very weak" Huygens' principle, which may be of independent interest. As applications of the estimate, we obtain a exponential local energy decay and a resonance wave expansion in odd dimensions, as well as a lossless local smoothing estimate for the Schr{\\"o}dinger equation.
High-Dimensional Data Fusion via Joint Manifold Learning Mark A. Davenport,s
that acquire large amounts of very high-dimensional data. To cope with such a data deluge, manifold models number of vantage points and using multiple modalities. This can lead to a veritable data deluge, fueling
. One way to cope with such a data deluge is to develop low-dimensional data models. Manifold models points and using multiple modalities. This can lead to a veritable data deluge, fueling the need
in detailed gas-phase chemical kinetics modeling, · detailed kinetics are essential for accurate modeling;Partial Review of Manifold Methods in Reactive Systems · The ILDM, CSP, and ICE-PIC are approximations
Mean-shift algorithms for manifold denoising, matrix completion and clustering
Wang, Weiran
2013-01-01T23:59:59.000Z
and the centroids found by K-means, K-modes, and mean-Rosasco. Learning manifolds with k- means and k-flats. In P.Huang. Extensions to the k-means algorithm for clustering
Manifold and method of batch measurement of Hg-196 concentration using a mass spectrometer
Grossman, M.W.; Evans, R.
1991-11-26T23:59:59.000Z
A sample manifold and method of its use has been developed so that milligram quantities of mercury can be analyzed mass spectroscopically to determine the [sup 196]Hg concentration to less than 0.02 atomic percent. Using natural mercury as a standard, accuracy of [+-]0.002 atomic percent can be obtained. The mass spectrometer preferably used is a commercially available GC/MS manufactured by Hewlett Packard. A novel sample manifold is contained within an oven allowing flow rate control of Hg into the MS. Another part of the manifold connects to an auxiliary pumping system which facilitates rapid clean up of residual Hg in the manifold. Sample cycle time is about 1 hour. 8 figures.
Manifold and method of batch measurement of Hg-196 concentration using a mass spectrometer
Grossman, Mark W. (Belmont, MA); Evans, Roger (N. Hampton, NH)
1991-01-01T23:59:59.000Z
A sample manifold and method of its use has been developed so that milligram quantities of mercury can be analyzed mass spectroscopically to determine the .sup.196 Hg concentration to less than 0.02 atomic percent. Using natural mercury as a standard, accuracy of .+-.0.002 atomic percent can be obtained. The mass spectrometer preferably used is a commercially available GC/MS manufactured by Hewlett Packard. A novel sample manifold is contained within an oven allowing flow rate control of Hg into the MS. Another part of the manifold connects to an auxiliary pumping system which facilitates rapid clean up of residual Hg in the manifold. Sample cycle time is about 1 hour.
Characterization and parameterization of the singular manifold of a simple 6-6 Stewart platform
T. Charters; P. Freitas
2008-11-07T23:59:59.000Z
This paper presents a study of the characterization of the singular manifold of the six-degree-of-freedom parallel manipulator commonly known as the Stewart platform. We consider a platform with base vertices in a circle and for which the bottom and top plates are related by a rotation and a contraction. It is shown that in this case the platform is always in a singular configuration and that the singular manifold can be parameterized by a scalar parameter.
Methods for dispersing hydrocarbons using autoclaved bacteria
Tyndall, R.L.
1996-11-26T23:59:59.000Z
A method of dispersing a hydrocarbon includes the following steps: providing a bacterium selected from the following group: ATCC 85527, ATCC 75529, and ATCC 55638, a mutant of any one of these bacteria possessing all the identifying characteristics of any one of these bacteria, and mixtures; autoclaving the bacterium to derive a dispersant solution; and contacting the dispersant solution with a hydrocarbon to disperse the hydrocarbon. Moreover, a method for preparing a dispersant solution includes the following steps: providing a bacterium selected from the following group: ATCC 75527, ATCC 75529, and ATCC 55638, a mutant of any one of these bacteria possessing all the identifying characteristics of any one of these bacteria, and mixtures; and autoclaving the bacterium to derive a dispersant solution.
Polyfunctional dispersants for controlling viscosity of phyllosilicates
Chaiko, David J.
2006-07-25T23:59:59.000Z
This invention provides phyllosilicates and polyfunctional dispersants which can be manipulated to selectively control the viscosity of phyllosilicate slurries. The polyfunctional dispersants used in the present invention, which include at least three functional groups, increase the dispersion and exfoliation of phyllosilicates in polymers and, when used in conjunction with phyllosilicate slurries, significantly reduce the viscosity of slurries having high concentrations of phyllosilicates. The functional groups of the polyfunctional dispersants are capable of associating with multivalent metal cations and low molecular weight organic polymers, which can be manipulated to substantially increase or decrease the viscosity of the slurry in a concentration dependent manner. The polyfunctional dispersants of the present invention can also impart desirable properties on the phyllosilicate dispersions including corrosion inhibition and enhanced exfoliation of the phyllosilicate platelets.
Superization of Homogeneous Spin Manifolds and Geometry of Homogeneous Supermanifolds
Andrea Santi
2009-05-24T23:59:59.000Z
Let M_0=G_0/H be a (pseudo)-Riemannian homogeneous spin manifold, with reductive decomposition g_0=h+m and let S(M_0) be the spin bundle defined by the spin representation Ad:H->\\GL_R(S) of the stabilizer H. This article studies the superizations of M_0, i.e. its extensions to a homogeneous supermanifold M=G/H whose sheaf of superfunctions is isomorphic to Lambda(S^*(M_0)). Here G is the Lie supergroup associated with a certain extension of the Lie algebra of symmetry g_0 to an algebra of supersymmetry g=g_0+g_1=g_0+S via the Kostant-Koszul construction. Each algebra of supersymmetry naturally determines a flat connection nabla^{S} in the spin bundle S(M_0). Killing vectors together with generalized Killing spinors (i.e. nabla^{S}-parallel spinors) are interpreted as the values of appropriate geometric symmetries of M, namely even and odd Killing fields. An explicit formula for the Killing representation of the algebra of supersymmetry is obtained, generalizing some results of Koszul. The generalized spin connection nabla^{S} defines a superconnection on M, via the super-version of a theorem of Wang.
Stretch fast dynamo mechanism via conformal mapping in Riemannian manifolds
Garcia de Andrade, L. C. [Departamento de Fisica Teorica, Instituto de Fisica, UERJ Rua Sao Fco. Xavier 524, Rio de Janeiro, RJ Maracana, CEP:20550-003 (Brazil)
2007-10-15T23:59:59.000Z
Two new analytical solutions of the self-induction equation in Riemannian manifolds are presented. The first represents a twisted magnetic flux tube or flux rope in plasma astrophysics, where the rotation of the flow implies that the poloidal field is amplified from toroidal field, in the spirit of dynamo theory. The value of the amplification depends on the Frenet torsion of the magnetic axis of the tube. Actually this result illustrates the Zeldovich stretch, twist, and fold method to generate dynamos from straight and untwisted ropes. Based on the fact that this problem was previously handled, using a Riemannian geometry of twisted magnetic flux ropes [Phys Plasmas 13, 022309 (2006)], investigation of a second dynamo solution, conformally related to the Arnold kinematic fast dynamo, is obtained. In this solution, it is shown that the conformal effect on the fast dynamo metric enhances the Zeldovich stretch, and therefore a new dynamo solution is obtained. When a conformal mapping is performed in an Arnold fast dynamo line element, a uniform stretch is obtained in the original line element.
Wagner, Anthony
-amino-5-phosphonovaleric acid (APV) infusions, whereas lateral perforant path plasticity can be attenuated by naloxone infusions. The present experiment was designed to evaluate the role of each entorhinal) changes in the overall configuration of environmental stimuli. Dorsal dentate gyrus infusions of either
Dispersion compensation for attosecond electron pulses
Hansen, Peter; Baumgarten, Cory; Batelaan, Herman; Centurion, Martin [Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (United States)
2012-08-20T23:59:59.000Z
We propose a device to compensate for the dispersion of attosecond electron pulses. The device uses only static electric and magnetic fields and therefore does not require synchronization to the pulsed electron source. Analogous to the well-known optical dispersion compensator, an electron dispersion compensator separates paths by energy in space. Magnetic fields are used as the dispersing element, while a Wien filter is used for compensation of the electron arrival times. We analyze a device with a size of centimeters, which can be applied to ultrafast electron diffraction and microscopy, and fundamental studies.
Method of dispersing a hydrocarbon using bacteria
Tyndall, Richard L. (Clinton, TN)
1996-01-01T23:59:59.000Z
New protozoan derived microbial consortia and method for their isolation are provided. Consortia and bacteria isolated therefrom are useful for treating wastes such as trichloroethylene and trinitrotoluene. Consortia, bacteria isolated therefrom, and dispersants isolated therefrom are useful for dispersing hydrocarbons such as oil, creosote, wax, and grease.
Broadband dispersion extraction using simultaneous sparse penalization
Saligrama, Venkatesh
the borehole and thus dispersion analysis is of considerable interest to the geophysical and oilfield services community. A brief survey of borehole acoustic waves and their use in mechanical characterization is a function of frequency. This function characterizes the mode and is referred to as a dispersion curve
Method of dispersing a hydrocarbon using bacteria
Tyndall, R.L.
1996-09-24T23:59:59.000Z
A new protozoan derived microbial consortia and method for their isolation are provided. The isolated consortia and bacteria are useful for treating wastes such as trichloroethylene and trinitrotoluene. The isolated consortia, bacteria, and dispersants are useful for dispersing hydrocarbons such as oil, creosote, wax, and grease.
Axion-medium effect on fermion dispersion
Mikheev, N. V., E-mail: mikheev@uniyar.ac.ru; Narynskaya, E. N., E-mail: elenan@uniyar.ac.r [Yaroslavl State University (Russian Federation)
2008-08-15T23:59:59.000Z
The interaction of fermions with a dense axion medium is considered with the aim of studying the effect of the axionmediumon fermion dispersion. It is shown that, if use is made of a correct Lagrangian for axion-fermion interaction, the effect of a dense axion medium on fermion dispersion is negligible under real astrophysical conditions.
A multifaceted approach to applying dispersants
Crain, O.L.
1982-10-01T23:59:59.000Z
A comprehensive oil spill response plan has been developed partially to deal with accidental discharges of oil into the Arabian Gulf. The spill response capabilities of contractor companies in the area are fairly limited. The response plan relies on chemical agents and recovery as cleanup tools. The key to effective response is a rapid response and deployment of cleanup equipment. Initially, marine vessels equipped with portable dispersant spray booms patterned after the Warren Springs equipment were used. To improve existing oil spill response, an extensive modernization of dispersant deployment equipment has been developed. The areas of modernization include upgrading the marine vessel equipment, dedicating boats and vessels of opportunity for dispersant application, using helicopters for spill response, using large fixed-wing aircraft for spill response, and establishing dispersant and refueling stockpiles. This paper discusses the use of dispersants in response to an oil spill. It is intended not as a scientific paper but as a paper on a local response capability.
Dispersion relations in noncommutative theories
Mariz, Tiago; Nascimento, J. R.; Rivelles, Victor O. [Departamento de Fisica, Universidade Federal da Paraiba, 58051-970, Joao Pessoa, PB (Brazil); Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318, 05315-970, Sao Paulo, SP (Brazil)
2007-01-15T23:59:59.000Z
We present a detailed study of plane waves in noncommutative abelian gauge theories. The dispersion relation is deformed from its usual form whenever a constant background electromagnetic field is present and is similar to that of an anisotropic medium with no Faraday rotation nor birefringence. When the noncommutativity is induced by the Moyal product we find that for some values of the background magnetic field no plane waves are allowed when time is noncommutative. In the Seiberg-Witten context no restriction is found. We also derive the energy-momentum tensor in the Seiberg-Witten case. We show that the generalized Poynting vector obtained from the energy-momentum tensor, the group velocity and the wave vector all point in different directions. In the absence of a constant electromagnetic background we find that the superposition of plane waves is allowed in the Moyal case if the momenta are parallel or satisfy a sort of quantization condition. We also discuss the relation between the solutions found in the Seiberg-Witten and Moyal cases showing that they are not equivalent.
IS-321-312-001 TEP-to-HTEP manifold interface sheet
Willms, R Scott [Los Alamos National Laboratory; Carlson, Bryan J [Los Alamos National Laboratory; Coons, James E [Los Alamos National Laboratory; Kubic, William L [Los Alamos National Laboratory
2008-01-01T23:59:59.000Z
The Tokamak Exhaust Processing System (TEP) receives hydrogen-like and air-like gas streams from the High Tritium Exhaust Processing (HTEP) manifold. Gases from the torus roughing pump are pumped into the HTEP manifold before entering TEP. This interface sheet describes the TEP-HTEP material stream interface, both the physical elements that make up the interface as well as the gas streams that will flow through the interface. The functions of this interface are to: Provide a physical connection for the transport of hydrogen-like and air-like gases from the HTEP manifold to TEP. Provide seals to prevent the unncessary release of tritium to the surrounding environment. Provide valves that can be actuated to stop or prevent the flow of gas into TEP.
Natural star-products on symplectic manifolds and related quantum mechanical operators
B?aszak, Maciej, E-mail: blaszakm@amu.edu.pl; Doma?ski, Ziemowit, E-mail: ziemowit@amu.edu.pl
2014-05-15T23:59:59.000Z
In this paper is considered a problem of defining natural star-products on symplectic manifolds, admissible for quantization of classical Hamiltonian systems. First, a construction of a star-product on a cotangent bundle to an Euclidean configuration space is given with the use of a sequence of pair-wise commuting vector fields. The connection with a covariant representation of such a star-product is also presented. Then, an extension of the construction to symplectic manifolds over flat and non-flat pseudo-Riemannian configuration spaces is discussed. Finally, a coordinate free construction of related quantum mechanical operators from Hilbert space over respective configuration space is presented. -- Highlights: •Invariant representations of natural star-products on symplectic manifolds are considered. •Star-products induced by flat and non-flat connections are investigated. •Operator representations in Hilbert space of considered star-algebras are constructed.
Zuo-Bing Wu
2008-03-17T23:59:59.000Z
In this paper, a method to construct topological template in terms of symbolic dynamics for the diamagnetic Kepler problem is proposed. To confirm the topological template, rotation numbers of invariant manifolds around unstable periodic orbits in a phase space are taken as an object of comparison. The rotation numbers are determined from the definition and connected with symbolic sequences encoding the periodic orbits in a reduced Poincar\\'e section. Only symbolic codes with inverse ordering in the forward mapping can contribute to the rotation of invariant manifolds around the periodic orbits. By using symbolic ordering, the reduced Poincar\\'e section is constricted along stable manifolds and a topological template, which preserves the ordering of forward sequences and can be used to extract the rotation numbers, is established. The rotation numbers computed from the topological template are the same as those computed from their original definition.
Stability Of Nanoclusters In 14YWT Oxide Dispersion Strengthened...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Stability Of Nanoclusters In 14YWT Oxide Dispersion Strengthened Steel Under Heavy Ion-irradiation By Atom Probe Tomography. Stability Of Nanoclusters In 14YWT Oxide Dispersion...
Photon statistics dispersion in excitonic composites
G. Ya. Slepyan; S. A. Maksimenko
2006-05-22T23:59:59.000Z
Linear media are predicted to exist whose relative permiability is an operator in the space of quantum states of light. Such media are characterized by a photon statistics--dependent refractive index. This indicates a new type of optical dispersion -- the photon statistics dispersion. Interaction of quantum light with such media modifies the photon number distribution and, in particular, the degree of coherence of light. An excitonic composite -- a collection of noninteracting quantum dots -- is considered as a realization of the medium with the photon statistics dispersion. Expressions are derived for generalized plane waves in an excitonic composite and input--output relations for a planar layer of the material. Transformation rules for different photon initial states are analyzed. Utilization of the photon statistics dispersion in potential quantum--optical devices is discussed.
On rank 2 vector bundles on Fano manifolds Roberto Mu~noz, Gianluca Occhetta, and Luis E. Sola Conde
Occhetta, Gianluca
On rank 2 vector bundles on Fano manifolds Roberto Mu~noz, Gianluca Occhetta, and Luis E. SolÂ´a~NOZ, GIANLUCA OCCHETTA, AND LUIS E. SOLÂ´A CONDE setting of rank two vector bundles on Fano manifolds of Picard
GAMMA-CONVERGENCE AND THE EMERGENCE OF VORTICES FOR GINZBURG-LANDAU ON THIN SHELLS AND MANIFOLDS
Sternberg, Peter
-Landau energy in the presence of an applied magnetic field when the superconducting sample occupies a thin neighborhood of a bounded, closed manifold in R3 . We establish -convergence to a reduced Ginzburg-Landau model critical points when the manifold M is a simply connected surface of revolution and the applied field
Topology of Homology Manifolds J. Bryant1, S. Ferry1, W. Mio1, and S. Weinberger1; 2
Mio, Washington
Topology of Homology Manifolds J. Bryant1, S. Ferry1, W. Mio1, and S. Weinberger1; 2 Florida State and Bryant-Lacher 7 , when the dimension of the singular set of the homology manifold is in the stable range
Utah, University of
of the population. We evaluate the proposed method on the OASIS and ADNI brain databases of head MR images in twoManifold modeling for brain population analysis Samuel Gerber *, Tolga Tasdizen, P. Thomas Fletcher Brain MRI Manifold learning Computer aided clinical diagnosis a b s t r a c t This paper describes
McGregor, Douglas S. (Riley, KS); Shultis, John K. (Manhattan, KS); Rice, Blake B. (Manhattan, KS); McNeil, Walter J. (Winnfield, KS); Solomon, Clell J. (Wichita, KS); Patterson, Eric L. (Manhattan, KS); Bellinger, Steven L. (Manhattan, KS)
2010-12-21T23:59:59.000Z
Non-streaming high-efficiency perforated semiconductor neutron detectors, method of making same and measuring wands and detector modules utilizing same are disclosed. The detectors have improved mechanical structure, flattened angular detector responses, and reduced leakage current. A plurality of such detectors can be assembled into imaging arrays, and can be used for neutron radiography, remote neutron sensing, cold neutron imaging, SNM monitoring, and various other applications.
Atmospheric dispersion in mountain valleys and basins
Allwine, K.J.
1992-01-01T23:59:59.000Z
The primary goal of the research is to further characterize and understand dispersion in valley and basin atmospheres. A secondary, and related goal, is to identify and understand the dominant physical processes governing this dispersion. This has been accomplished through a review of the current literature, and analyses of recently collected data from two field experiments. This work should contribute to an improved understanding of material transport in the atmospheric boundary layer. It was found that dispersion in a freely draining valley (Brush Creek valley, CO) atmosphere is much greater than in an enclosed basin (Roanoke, VA) atmosphere primarily because of the greater wind speeds moving past the release point and the greater turbulence levels. The development of a cold air pool in the Roanoke basin is the dominant process governing nighttime dispersion in the basin, while the nighttime dispersion in the Brush Creek valley is dominated by turbulent diffusion and plume confinement between the valley sidewalls. The interaction between valley flows and above ridgetops flows is investigated. A ventilation rate'' of material transport between the valley and above ridgetop flows is determined. This is important in regional air pollution modeling and global climate modeling. A simple model of dispersion in valleys, applicable through a diurnal cycle, is proposed.
Atmospheric dispersion in mountain valleys and basins
Allwine, K.J.
1992-01-01T23:59:59.000Z
The primary goal of the research is to further characterize and understand dispersion in valley and basin atmospheres. A secondary, and related goal, is to identify and understand the dominant physical processes governing this dispersion. This has been accomplished through a review of the current literature, and analyses of recently collected data from two field experiments. This work should contribute to an improved understanding of material transport in the atmospheric boundary layer. It was found that dispersion in a freely draining valley (Brush Creek valley, CO) atmosphere is much greater than in an enclosed basin (Roanoke, VA) atmosphere primarily because of the greater wind speeds moving past the release point and the greater turbulence levels. The development of a cold air pool in the Roanoke basin is the dominant process governing nighttime dispersion in the basin, while the nighttime dispersion in the Brush Creek valley is dominated by turbulent diffusion and plume confinement between the valley sidewalls. The interaction between valley flows and above ridgetops flows is investigated. A ``ventilation rate`` of material transport between the valley and above ridgetop flows is determined. This is important in regional air pollution modeling and global climate modeling. A simple model of dispersion in valleys, applicable through a diurnal cycle, is proposed.
COMPRESSIVE VIDEO CLASSIFICATION IN A LOW-DIMENSIONAL MANIFOLD WITH LEARNED DISTANCE METRIC
Tsakalides, Panagiotis
COMPRESSIVE VIDEO CLASSIFICATION IN A LOW-DIMENSIONAL MANIFOLD WITH LEARNED DISTANCE METRIC George Tzagkarakis1 , Grigorios Tsagkatakis2 , Jean-Luc Starck1 and Panagiotis Tsakalides2 1 Commissariat `a l'Â´Energie of video classification based on a set of com- pressed features, without the need of accessing the original
Manifold-based starting point generation and its application to distillation
Neumaier, Arnold
Manifold-based starting point generation and its application to distillation Ali Baharev*, Ferenc-states in homogeneous azeotropic distillation . . . . . . . . . . 11 5.2 Multiple steady-states in ideal two-product distillation . . . . . . . . . . . . . . 11 6 Conclusion 13 A Ordering sparse matrices 14 A.1 Ordering to block
Side branch absorber for exhaust manifold of two-stroke internal combustion engine
Harris, Ralph E. (San Antonio, TX); Broerman, III, Eugene L. (San Antonio, TX); Bourn, Gary D. (Laramie, WY)
2011-01-11T23:59:59.000Z
A method of improving scavenging operation of a two-stroke internal combustion engine. The exhaust pressure of the engine is analyzed to determine if there is a pulsation frequency. Acoustic modeling is used to design an absorber. An appropriately designed side branch absorber may be attached to the exhaust manifold.
DEHN SURGERIES ON 2-BRIDGE LINKS WHICH YIELD REDUCIBLE 3-MANIFOLDS
Hachimori, Masahiro
) 1 = -w + u + 1 and 2 = -w + u - 1. (b) 1 = -w + u and 2 = -w + u. (2) w = 1, u = -2 and 1 = -1 and 2 -2 is a reducible 3-manifold if and only if it is one of the followings or its mirror image. (1) (a
ANALYTIC EQUIVALENCE OF NORMAL CROSSING FUNCTIONS ON A REAL ANALYTIC MANIFOLD
Paris-Sud XI, Université de
ANALYTIC EQUIVALENCE OF NORMAL CROSSING FUNCTIONS ON A REAL ANALYTIC MANIFOLD Goulwen Fichou crossing singularities after a modification. We focus on the analytic equivalence of such functions with only normal crossing singularities. We prove that for such functions C right equivalence implies
Water Pentamer: Characterization of the Torsional-Puckering Manifold by Terahertz VRT Spectroscopy
Cohen, Ronald C.
Water Pentamer: Characterization of the Torsional-Puckering Manifold by Terahertz VRT Spectroscopy Heather A. Harker, Mark R. Viant, Frank N. Keutsch,Â§ Ernest A. Michael,| Ryan P. McLaughlin, and Richard J observation of this perturbation in the perdeuterated water pentamer, as well as the first observation
Learning Manifolds with K-Means and K-Flats Guille D. Canas ,
Poggio, Tomaso
Learning Manifolds with K-Means and K-Flats Guille D. Canas , Tomaso Poggio , Lorenzo A. Rosasco samples. In particular, we consider piecewise constant and piecewise linear estima- tors induced by k-means and k-flats, and analyze their performance. We extend previous results for k-means in two separate
markets. Index Terms-- Electricity spot price, locational marginal price, electricity forward curveIEEE TRANSACTIONS ON POWER SYSTEMS, CHEN, DENG AND HUO. 1 Electricity Price Curve Modeling and prediction of electricity price curves by applying the manifold learning methodology. Cluster analysis based
Krysl, Svatopluk
C -algebras Oscillator or Segal-Shale-Weil representation Geometry: Associating the oscillator or Segal-Shale-Weil representation Geometry: Associating the oscillator to symplectic manifolds Global and (x) = 0 implies x = 0 2 S. KrÃ½sl #12;C -algebras Oscillator or Segal-Shale-Weil representation
Natural Conjugate Gradient on Complex Flag Manifolds for Complex Independent Subspace
Plumbley, Mark
conjugate gradient method yields better convergence compared to the natural gradient geodesic search method is the natural gradient geodesic search method (NGS), and the other is the natural conjugate gradient method (NCG the natural gradient or the Newton's method on complex manifolds, however, the behavior of the conjugate
Convergence and Rate of Convergence of A Manifold-Based Dimension Reduction Algorithm
Huo, Xiaoming
of a particular manifold- based learning algorithm: LTSA [12]. The main technical tool is the perturbation analysis on the linear invariant subspace that corresponds to the solution of LTSA. We derive the upper bound for errors under the worst case for LTSA; it naturally leads to a convergence result. We
Type Master Thesis Title TV based image processing for manifold-valued data
Grohs, Philipp
Type Master Thesis Title TV based image processing for manifold-valued data Advisor PROF. PHILIPP of a numerical array of real values (as e.g. in grey-value images) but rather of arrays (matrices) whose elements images, covariance matrices arising in radar observatory data, etc... The challenge is to extend
Paris-Sud XI, Université de
Reduction, Centre Manifold, Robust Analysis, Uncertainty Propagation, Polynomial chaos, Non-intrusive to compute the deterministic components called stochastic modes in an intrusive and a non intrusive manner while random components are concentrated in the polynomial basis used. Non intrusive procedures
Machine Learning for Seismic Signal Processing: Seismic Phase Classification on a Manifold
Meyer, Francois
Machine Learning for Seismic Signal Processing: Seismic Phase Classification on a Manifold Juan--In this research, we consider the supervised learning problem of seismic phase classification. In seismology, knowledge of the seismic activity arrival time and phase leads to epicenter localization and surface
Computing Lyapunov exponents on a Stiefel manifold by Thomas J. Bridges and Sebastian Reich
Reich, Sebastian
Computing Lyapunov exponents on a Stiefel manifold by Thomas J. Bridges and Sebastian Reich The problem of numerical computation of a few Lyapunov exponents of #12;nite-dimensional dynamical systems computes one, many or all Lyapunov exponents of a continuous dynamical system by time integration, discrete
university-logo Two papers which changed my life: Milnor's seminal work on flat manifolds
Goldman, William
university-logo Two papers which changed my life: Milnor's seminal work on flat manifolds Two Banff International Research Station February 24, 2011 #12;university-logo Two papers which changed my of Euclidean 3-space by free groups of affine transformations. #12;university-logo Two papers which changed my
A Tracer Investigation oftheAtmosph^c Dispersion
and a sea-breeze. INIS-descriptors: AIR POLLUTION; DILUTION; DISPERSION; ENVIRONMENTAL IMPACTS; GASES
Hamiltonian dynamics of breathers with third-order dispersion
Mookherjea, Shayan; Yariv, Amnon
2001-08-01T23:59:59.000Z
We present a nonperturbative analysis of certain dynamical aspects of breathers (dispersion-managed solitons) including the effects of third-order dispersion. The analysis highlights the similarities to and differences from the well-known analogous procedures for second-order dispersion. We discuss in detail the phase-space evolution of breathers in dispersion-managed systems in the presence of third-order dispersion. {copyright} 2001 Optical Society of America
Carbon Nanotubes: Measuring Dispersion and Length
Fagan, Jeffrey A.; Bauer, Barry J.; Hobbie, Erik K.; Becker, Matthew L.; Hight-Walker, Angela; Simpson, Jeffrey R.; Chun, Jaehun; Obrzut, Jan; Bajpai, Vardhan; Phelan, Fred R.; Simien, Daneesh; Yeon Huh, Ji; Migler, Kalman B.
2011-03-01T23:59:59.000Z
Advanced technological uses of single-wall carbon nanotubes (SWCNTs) rely on the production of single length and chirality populations that are currently only available through liquid phase post processing. The foundation of all of these processing steps is the attainment of individualized nanotube dispersion in solution; an understanding of the collodial properties of the dispersed SWCNTs can then be used to designed appropriate conditions for separations. In many instances nanotube size, particularly length, is especially active in determining the achievable properties from a given population, and thus there is a critical need for measurement technologies for both length distribution and effective separation techniques. In this Progress Report, we document the current state of the art for measuring dispersion and length populations, including separations, and use examples to demonstrate the desirability of addressing these parameters.
Ceramics containing dispersants for improved fracture toughness
Nevitt, Michael V. (Wheaton, IL); Aldred, Anthony T. (Wheaton, IL); Chan, Sai-Kit (Darien, IL)
1987-01-01T23:59:59.000Z
The invention is a ceramic composition containing a new class of dispersant for hindering crack propagation by means of one or more energy-dissipative mechanisms. The composition is composed of a ceramic matrix with dispersed particles of a transformation-prone rare-earth niobate, tantalate or mixtures of these with each other and/or with a rare-earth vanadate. The dispersants, having a generic composition tRMO.sub.4, where R is a rare-earth element, B is Nb or Ta and O is oxygen, are mixed in powder form with a powder of the matrix ceramic and sintered to produce a ceramic form or body. The crack-hindering mechanisms operates to provide improved performance over a wide range of temperature and operating conditions.
Method of dispersing particulate aerosol tracer
O'Holleran, Thomas P. (Belleville, MI)
1988-01-01T23:59:59.000Z
A particulate aerosol tracer which comprises a particulate carrier of sheet silicate composition having a particle size up to one micron, and a cationic dopant chemically absorbed in solid solution in the carrier. The carrier is preferably selected from the group consisting of natural mineral clays such as bentonite, and the dopant is selected from the group consisting of rare earth elements and transition elements. The tracers are dispersed by forming an aqueous salt solution with the dopant present as cations, dispersing the carriers in the solution, and then atomizing the solution under heat sufficient to superheat the solution droplets at a level sufficient to prevent reagglomeration of the carrier particles.
SOLVENT DISPERSION AND FLOW METER CALCULATION RESULTS
Nash, C.; Fondeur, F.; Peters, T.
2013-06-21T23:59:59.000Z
Savannah River National Laboratory (SRNL) found that the dispersion numbers for the six combinations of CSSX:Next Generation Solvent (NGS) “blend” and pure NGS versus salt solution, caustic wash, and strip aqueous solutions are all good. The dispersion numbers are indications of processability with centrifugal contactors. A comparison of solvent physical and thermal properties shows that the Intek™ solvent flow meter in the plant has a reading biased high versus calibrated flow when NGS is used, versus the standard CSSX solvent. The flow meter, calibrated for CSSX solvent, is predicted to read 2.8 gpm of NGS in a case where the true flow of NGS is 2.16 gpm.
Fall Rubber Colloquium CHARACTERIZATION OF DISPERSION
Paris-Sud XI, Université de
9th Fall Rubber Colloquium CHARACTERIZATION OF DISPERSION MECHANISMS OF AGGLOMERATED FILLERS (styrene-butadiene rubber). The objective was to determine the role of the intrinsic parameters Carbon black and silica are widely used as reinforcing fillers for rubber compounds in the tire industry
Victor Kalvin
2010-07-25T23:59:59.000Z
In this paper we continue our study of the Laplacian on manifolds with axial analytic asymptotically cylindrical ends initiated in~arXiv:1003.2538. By using the complex scaling method and the Phragm\\'{e}n-Lindel\\"{o}f principle we prove exponential decay of the eigenfunctions corresponding to the non-threshold eigenvalues of the Laplacian on functions. In the case of a manifold with (non-compact) boundary it is either the Dirichlet Laplacian or the Neumann Laplacian. We show that the rate of exponential decay of an eigenfunction is prescribed by the distance from the corresponding eigenvalue to the next threshold. Under our assumptions on the behaviour of the metric at infinity accumulation of isolated and embedded eigenvalues occur. The results on decay of eigenfunctions combined with the compactness argument due to Perry imply that the eigenvalues can accumulate only at thresholds and only from below. The eigenvalues are of finite multiplicity.
Bose-Einstein Condensation on a Manifold with Nonnegative Ricci Curvature
Levent Akant; Emine Ertugrul; Ferzan Tapramaz; O. Teoman Turgut
2014-03-28T23:59:59.000Z
The Bose-Einstein condensation for an ideal Bose gas and for a dilute weakly interacting Bose gas in a manifold with nonnegative Ricci curvature is investigated using the heat kernel and eigenvalue estimates of the Laplace operator. The main focus is on the nonrelativistic gas. However, special relativistic ideal gas is also discussed. The thermodynamic limit of the heat kernel and eigenvalue estimates is taken and the results are used to derive bounds for the depletion coefficient. In the case of a weakly interacting gas Bogoliubov approximation is employed. The ground state is analyzed using heat kernel methods and finite size effects on the ground state energy are proposed. The justification of the c-number substitution on a manifold is given.
Extension of distributions, scalings and renormalization of QFT on Riemannian manifolds
Nguyen Viet Dang
2014-11-13T23:59:59.000Z
Let $M$ be a smooth manifold and $X\\subset M$ a closed subset of $M$. In this paper, we introduce a natural condition of \\emph{moderate growth} along $X$ for a distribution $t$ in $\\mathcal{D}^\\prime(M\\setminus X)$ and prove that this condition is equivalent to the existence of an extension of $t$ in $\\mathcal{D}^\\prime(M)$ generalizing some previous results of Meyer and Brunetti--Fredenhagen. When $X$ is a closed submanifold of $M$, we show that the concept of distributions with moderate growth coincides with weakly homogeneous distributions of Meyer. Then we renormalize products of distributions with functions tempered along $X$ and finally, using the whole analytical machinery developed, we give an existence proof of perturbative quantum field theories on Riemannian manifolds.
The Construction of Spinor Fields on Manifolds with Smooth Degenerate Metrics
J Schray; T Dray; C A Manogue; R W Tucker; C Wang
1996-05-17T23:59:59.000Z
We examine some of the subtleties inherent in formulating a theory of spinors on a manifold with a smooth degenerate metric. We concentrate on the case where the metric is singular on a hypersurface that partitions the manifold into Lorentzian and Euclidean domains. We introduce the notion of a complex spinor fibration to make precise the meaning of continuity of a spinor field and give an expression for the components of a local spinor connection that is valid in the absence of a frame of local orthonormal vectors. These considerations enable one to construct a Dirac equation for the discussion of the behavior of spinors in the vicinity of the metric degeneracy. We conclude that the theory contains more freedom than the spacetime Dirac theory and we discuss some of the implications of this for the continuity of conserved currents.
Infrared divergence of a scalar quantum field model on a pseudo Riemannian manifold
C. Gérard; F. Hiroshima; A. Panati; A. Suzuki
2011-03-18T23:59:59.000Z
A scalar quantum field model defined on a pseudo Riemann manifold is considered. The model is unitarily transformed the one with a variable mass. By means of a Feynman-Kac-type formula, it is shown that when the variable mass is short range, the Hamiltonian has no ground state. Moreover the infrared divergence of the expectation values of the number of bosons in the ground state is discussed.
Energy identity of approximate biharmonic maps to Riemannian manifolds and its application
Wang, Changyou
2011-01-01T23:59:59.000Z
We consider in dimension four weakly convergent sequences of approximate biharmonic maps to a Riemannian manifold with bi-tension fields bounded in $L^p$ for $p>\\frac43$. We prove an energy identity that accounts for the loss of hessian energies by the sum of hessian energies over finitely many nontrivial biharmonic maps on $\\mathbb R^4$. As a corollary, we obtain an energy identity for the heat flow of biharmonic maps at time infinity.
Perforation patterned electrical interconnects
Frey, Jonathan
2014-01-28T23:59:59.000Z
This disclosure describes systems and methods for increasing the usable surface area of electrical contacts within a device, such as a thin film solid state device, through the implementation of electrically conductive interconnects. Embodiments described herein include the use of a plurality of electrically conductive interconnects that penetrate through a top contact layer, through one or more multiple layers, and into a bottom contact layer. The plurality of conductive interconnects may form horizontal and vertical cross-sectional patterns. The use of lasers to form the plurality of electrically conductive interconnects from reflowed layer material further aids in the manufacturing process of a device.
On the reduction of oxygen from dispersed media
Roushdy, Omar H., 1977-
2007-01-01T23:59:59.000Z
The reduction of oxygen from an organic phase dispersed in a concentrated electrolyte is investigated. Dispersed organic phases are used to enhance oxygen transport in fermenters and artificial blood substitutes. This work ...
Update 5 to: A Dispersion Modeling Analysis of Downwash from...
Office of Environmental Management (EM)
5 to: A Dispersion Modeling Analysis of Downwash from Mirant's Potomac River Power Plant: Modeling Cycling Units 1, 2 plus One Baseload Unit Update 5 to: A Dispersion Modeling...
Geographic dispersion in teams : its history, experience, measurement, and change
O'Leary, Michael Boyer, 1969-
2002-01-01T23:59:59.000Z
This thesis begins with the simple argument that geographic dispersion has gone surprisingly unexamined despite its role as the domain-defining construct for geographically dispersed teams (a.k.a. "virtual teams"). The ...
Thermal boundary layer development in dispersed flow film boiling
Hull, Lawrence M.
1982-01-01T23:59:59.000Z
Dispersed flow film boiling consists of a dispersion of droplets which are carried over a very hot surface by their vapor. This process occurs in cryogenic equipment and wet steam turbines. It is also of interest in the ...
Dryout droplet distribution and dispersed flow film boiling
Hill, Wayne S.
1982-01-01T23:59:59.000Z
Dispersed flow film boiling is characterized by liquid-phase droplets entrained in a continuous vapor-phase flow. In a previous work at MIT, a model of dispersed flow heat transfer was developed, called the Local Conditions ...
air pollution dispersal: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Environmental Pollution Air Pollution Dispersion Practical Air Pollution Dispersion Geosciences Websites Summary:...
air pollutant dispersion: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Environmental Pollution Air Pollution Dispersion Practical Air Pollution Dispersion Geosciences Websites Summary:...
Dispersion-free radial transmission lines
Caporaso, George J. (Livermore, CA); Nelson, Scott D. (Patterson, CA)
2011-04-12T23:59:59.000Z
A dispersion-free radial transmission line ("DFRTL") preferably for linear accelerators, having two plane conductors each with a central hole, and an electromagnetically permeable material ("EPM") between the two conductors and surrounding a channel connecting the two holes. At least one of the material parameters of relative magnetic permeability, relative dielectric permittivity, and axial width of the EPM is varied as a function of radius, so that the characteristic impedance of the DFRTL is held substantially constant, and pulse transmission therethrough is substantially dispersion-free. Preferably, the EPM is divided into concentric radial sections, with the varied material parameters held constant in each respective section but stepwise varied between sections as a step function of the radius. The radial widths of the concentric sections are selected so that pulse traversal time across each section is the same, and the varied material parameters of the concentric sections are selected to minimize traversal error.
Quantum ratchet transport with minimal dispersion rate
Zhan, Fei; Ponomarev, A V; Hänggi, P
2011-01-01T23:59:59.000Z
We analyze the performance of quantum ratchets by considering the dynamics of an initially localized wave packet loaded into a flashing periodic potential. The directed center-of-mass motion can be initiated by the uniform modulation of the potential height, provided that the modulation protocol breaks all relevant time- and spatial reflection symmetries. A poor performance of quantum ratchet transport is characterized by a slow net motion and a fast diffusive spreading of the wave packet, while the desirable optimal performance is the contrary. By invoking a quantum analog of the classical P\\'eclet number, namely the quotient of the group velocity and the dispersion of the propagating wave packet, we calibrate the transport properties of flashing quantum ratchets and discuss the mechanisms that yield low-dispersive directed transport.
Quantum ratchet transport with minimal dispersion rate
Fei Zhan; S. Denisov; A. V. Ponomarev; P. Hänggi
2011-10-11T23:59:59.000Z
We analyze the performance of quantum ratchets by considering the dynamics of an initially localized wave packet loaded into a flashing periodic potential. The directed center-of-mass motion can be initiated by the uniform modulation of the potential height, provided that the modulation protocol breaks all relevant time- and spatial reflection symmetries. A poor performance of quantum ratchet transport is characterized by a slow net motion and a fast diffusive spreading of the wave packet, while the desirable optimal performance is the contrary. By invoking a quantum analog of the classical P\\'eclet number, namely the quotient of the group velocity and the dispersion of the propagating wave packet, we calibrate the transport properties of flashing quantum ratchets and discuss the mechanisms that yield low-dispersive directed transport.
Some Thermodynamic Properties of Colloidal Dispersions
de Thier, Pierre
2013-01-01T23:59:59.000Z
In this paper, some results are derived to describe the out-of-equilibrium thermodynamics of colloidal suspensions. These results are obtained assuming that the properties of the colloids essentially come from their surfaces which are unusually high in comparison to their volume. The dispersion, in the form of a variable, is introduced in such a way as to embody the various changes which could affect those systems. Explicit relations are deduced for the free enthalpy of dispersion which describe two separated phenomena: the peptization/coalescence and the suspension of a colloidal phase. An alternative to the Gibbs' adsorption equation allows to explain how a surface relaxes thanks to adsorptions. Finally, a link between conformational entropy changes and surface entropy production is discussed with the idea to be applied to the well known protein folding problem.
Externally Dispersed Interferometry for Precision Radial Velocimetry
Erskine, D J; Muterspaugh, M W; Edelstein, J; Lloyd, J; Herter, T; Feuerstein, W M; Muirhead, P; Wishnow, E
2007-03-27T23:59:59.000Z
Externally Dispersed Interferometry (EDI) is the series combination of a fixed-delay field-widened Michelson interferometer with a dispersive spectrograph. This combination boosts the spectrograph performance for both Doppler velocimetry and high resolution spectroscopy. The interferometer creates a periodic spectral comb that multiplies against the input spectrum to create moire fringes, which are recorded in combination with the regular spectrum. The moire pattern shifts in phase in response to a Doppler shift. Moire patterns are broader than the underlying spectral features and more easily survive spectrograph blurring and common distortions. Thus, the EDI technique allows lower resolution spectrographs having relaxed optical tolerances (and therefore higher throughput) to return high precision velocity measurements, which otherwise would be imprecise for the spectrograph alone.
Spatial Dispersion of Peering Clusters in the European Internet
D'Ignazio, Alessio; Giovannetti, Emanuele
2006-03-14T23:59:59.000Z
), both showing some degree of dispersion. 6 We would like ti thank Dr Fingleton for helpful suggestions on this topic...
Determination of Longitudinal Dispersion Coefficient and Net
Ho, David
with a Large-Scale, High Resolution SF6 Tracer Release Experiment D A V I D T . H O , * , P E T E R S C H L O into rivers. In the following, we report results from a large-scale SF6 tracer release experiment conducted in the tidal Hudson River to examine longitudinal dispersion and net advection. SF6 was injected
Dense gas dispersion modeling for aqueous releases
Lara, Armando
1999-01-01T23:59:59.000Z
DENSE GAS DISPERSION MODELING FOR AQUEOUS RELEASES A Thesis by ARMANDO LARA Submitted to the Office of Graduate Studies of Texas A&M University In partial fulfill ment of the requirements for the degree of MASTER OF SCIENCE May 1999 Major... Modeling for Aqueous Releases. (May 1999) Armando Lara, B. S. , University of Houston Chair of Advisory Committee: Dr. Sam Mannan Production, transportation, and storage of hazardous chemicals represent potential risks to the environment, the public...
Dispersants Forum: Gulf of Mexico Oil Spill & Ecosystem Science
New Hampshire, University of
Dispersants Forum: Gulf of Mexico Oil Spill & Ecosystem Science Conference What have we & Restoration, Gulf of Mexico Disaster Response Center 2.3. Characterizing Dispersant and Dispersed Oil Effects The content for this workshop was developed in cooperation with the Gulf of Mexico Research Initiative (Go
Kelley; Dana A. (New Milford, CT), Farooque; Mohammad (Danbury, CT), Davis; Keith (Southbury, CT)
2007-10-02T23:59:59.000Z
A fuel cell system with improved electrical isolation having a fuel cell stack with a positive potential end and a negative potential, a manifold for use in coupling gases to and from a face of the fuel cell stack, an electrical isolating assembly for electrically isolating the manifold from the stack, and a unit for adjusting an electrical potential of the manifold such as to impede the flow of electrolyte from the stack across the isolating assembly.
Economics of selected WECS dispersed applications
Krawiec, S.
1980-02-01T23:59:59.000Z
An economic analysis for distributed Wind Energy Conversion Systems (WECS) was conducted for the Department of Energy (DOE) as part of the Solar Commercial Readiness Assessment task at the Solar Energy Research Institute (SERI). The major objective of the study is to analyze: the cost of electricity generated by selected wind energy systems in residential and agricultural applications; the breakeven cost of wind systems able to compete economically with conventional power sources in dispersed applications; and the impact of major economic factors on the cost performance index.
NYO-7593 LECTIJHES ON DISPERSION THEORY
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AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for Renewable Energy: GridTruck PlatooningJefferson7593 LECTIJHES ON DISPERSION THEORY by
Eigenvalues of Killing Tensors and Separable Webs on Riemannian and Pseudo-Riemannian Manifolds
Claudia Chanu; Giovanni Rastelli
2007-02-12T23:59:59.000Z
Given a $n$-dimensional Riemannian manifold of arbitrary signature, we illustrate an algebraic method for constructing the coordinate webs separating the geodesic Hamilton-Jacobi equation by means of the eigenvalues of $m \\leq n$ Killing two-tensors. Moreover, from the analysis of the eigenvalues, information about the possible symmetries of the web foliations arises. Three cases are examined: the orthogonal separation, the general separation, including non-orthogonal and isotropic coordinates, and the conformal separation, where Killing tensors are replaced by conformal Killing tensors. The method is illustrated by several examples and an application to the L-systems is provided.
Mariz, T.; Menezes, R.; Nascimento, J.R.S.; Ribeiro, R.F. [Departamento de Fisica, Universidade Federal da Paraiba, 58051-970 Joao Pessoa, Paraiba (Brazil); Wotzasek, C. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, 21945 Rio de Janeiro (Brazil)
2004-10-15T23:59:59.000Z
We study issues of duality and dual equivalence in noncommutative manifolds. In particular, the question of dual equivalence for the actions of the noncommutative extensions of the self-dual model in 3D space-time and the Maxwell-Chern-Simons model is investigated. We show that former model is not dual equivalent to the noncommutative extension of the Maxwell-Chern-Simons model, as widely believed, but a deformed version of it that is disclosed here. Our results are not restricted to any finite order in the Seiberg-Witten expansion involving the noncommutative parameter {theta}.
Fate of commercial disperse dyes in sediments
Yen, C.P.C.; Perenich, T.A.; Baughman, G.L.
1991-01-01T23:59:59.000Z
Kinetics of disappearance of seven different disperse dyes were determined in compacted sediments at room temperature. The commercial dyes (in dispersed solid form) were representative of nitroazo, anthraquinone, and quinoline structures that are widely used. Reaction rates were found to be first order over at least two half-lives and were different for the three groups of dyes. Half-lives were on the order of hours, days and months for the nitroazobenzene, aminoanthraquinone, and quinoline dyes, respectively. Stability of the latter is consistent with detection of a quinoline dye in treatment plant sludge and in sediment from a water body receiving treated effluent. The azobenzene dyes are degraded by cleavage of the azo group to give anilines and ring-substituted phenylenediamines from the diazo component of the molecule. Products from the other portion (coupling component) of the molecule are unidentified, as yet, but are expected to be N,N-disubstituted phenylenediamines. Products of the anthraquinone dyes were unidentified, except for the case of a nitrated dye on which the nitro group was reduced.
Evaluation of machining dispersions for turning process
Arnaud Lefebvre; Valery Wolff
2008-03-03T23:59:59.000Z
In this article we propose to extend the model of simulation of dispersions in turning based on the geometrical specifications. Our study is articulated around two trends of development: the first trend relates to the geometrical model. The geometrical model suggested must allow a follow-up of the geometry of the part during the simulation of machining. It is thus a question of carrying out a systematic treatment of the whole dimensioning and tolerancing process while being based on the principles of the \\DeltaL method. We also planned to integrate this type of specification in the model of simulation of machining suggested. It is more generally a question of extending the traditional model for better taking into account the multi axis specification of coaxiality and perpendicularity on the turned workpieces. The second trend of our study relates to the widening of the field of application of the model. We propose to extend the field of application of the model by taking into account the modifications of several parameters of the manufacturing process plans, likely to involve variations of dispersions.
Falicoff, Waqidi; Chaves, Julio C.; Minano, Juan Carlos; Benitez, Pablo; Dross, Oliver; Parkyn, Jr., William A.
2010-02-23T23:59:59.000Z
Optical systems are described that have at least one source of a beam of blue light with divergence under 15.degree.. A phosphor emits yellow light when excited by the blue light. A collimator is disposed with the phosphor and forms a yellow beam with divergence under 15.degree.. A dichroic filter is positioned to transmit the beam of blue light to the phosphor and to reflect the beam of yellow light to an exit aperture. In different embodiments, the beams of blue and yellow light are incident upon said filter with central angles of 15.degree., 22.degree., and 45.degree.. The filter may reflect all of one polarization and part of the other polarization, and a polarization rotating retroreflector may then be provided to return the unreflected light to the filter.
Pauwels, M.A.; Wright, D.O.
1986-07-15T23:59:59.000Z
A microprocessor based electronic engine control system is described for an internal combustion engine, a method for updating the stored ambient pressure signal by measuring the ambient barometric pressure during engine operation using a manifold pressure sensor. The method consists of: generating timing signals indicating the rotational position of an engine member and including a signal indicating a predetermined rotational position in the rotation of the engine member; generating a pressure signal from the manifold pressure sensor representing the pressure surrounding the sensor in response to the predetermined rotational position; reading the value of ambient barometric pressure stored in the memory of the microprocessor; comparing the value of the barometric pressure stored in the memory of the microprocessor and the value of the pressure signal; increasing the value of the barometric pressure by one unit to generate a new barometric pressure value when the value of the pressure signal is greater than the value of the barometric pressure; comparing the new barometric pressure value with a predetermined fixed constant representing the maximum barometric pressure; and storing in the memory of the microprocessor either the new barometric pressure value if equal to or less than the fixed constant or the value of the maximum barometric pressure if the new barometric pressure value is greater than the fixed constant.
Hyper dispersion pulse compressor for chirped pulse amplification systems
Barty, Christopher P. J. (Hayward, CA)
2011-11-29T23:59:59.000Z
A grating pulse compressor configuration is introduced for increasing the optical dispersion for a given footprint and to make practical the application for chirped pulse amplification (CPA) to quasi-narrow bandwidth materials, such as Nd:YAG. The grating configurations often use cascaded pairs of gratings to increase angular dispersion an order of magnitude or more. Increased angular dispersion allows for decreased grating separation and a smaller compressor footprint.
Effect of the Ligand Shell Composition on the Dispersibility...
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Dispersibility-vs-density plots are obtained by following the variation in the Surface Plasmon Resonance (SPR) absorption spectra of the nanoparticles. To better understand the...
Update 3 to: A Dispersion Modeling Analysis of Downwash from...
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Update 2 to: A Dispersion Modeling Analysis of Downwash from Mirant's Potomac River Power Plant, Modeling Units 1 and 4 Together More Documents & Publications Update 1 to: A...
Update 6 to: A Dispersion Modeling Analysis of Downwash from...
Broader source: Energy.gov (indexed) [DOE]
Update 6 to: A Dispersion Modeling Analysis of Downwash from Mirant's Potomac River Power Plant Modeling Baseload Units 3,4,5 More Documents & Publications Attachment A: Modeling...
Supercontinuum generation in photonic crystal fibres: Modelling and dispersion engineering
Supercontinuum generation in photonic crystal fibres: Modelling and dispersion engineering . . . . . . . . . . . . . . . . . 22 2.4 The split-step Fourier method . . . . . . . . . . . . . . . . . . 25 #12;iv CONTENTS 2
Update 4 to: A Dispersion Modeling Analysis of Downwash from...
Office of Environmental Management (EM)
Analysis of Downwash from Mirant's Potomac River Power Plant, Modeling Unit 4 Emissions at Maximum and Minimum Loads Update 4 to: A Dispersion Modeling Analysis of Downwash...
Update 2 to: A Dispersion Modeling Analysis of Downwash from...
Office of Environmental Management (EM)
Analysis of Downwash from Mirant's Potomac River Power Plant, Modeling Unit 1 Emissions at Maximum and Minimum Loads Update 2 to: A Dispersion Modeling Analysis of Downwash...
Update 1 to: A Dispersion Modeling Analysis of Downwash from...
Office of Environmental Management (EM)
Analysis of Downwash from Mirant's Potomac River Power Plant, Modeling Unit 1 Emissions in a Cycling Mode Update 1 to: A Dispersion Modeling Analysis of Downwash from...
atmospheric dispersion coefficient: Topics by E-print Network
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the earth surface. In general, the atmospheric motion is driven by the intense solar energy arriving at the equator 3 A GIS-based atmospheric dispersion model Computer...
atmospheric dispersion calculations: Topics by E-print Network
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the earth surface. In general, the atmospheric motion is driven by the intense solar energy arriving at the equator 4 A GIS-based atmospheric dispersion model Computer...
atmospheric dispersion experiment: Topics by E-print Network
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the earth surface. In general, the atmospheric motion is driven by the intense solar energy arriving at the equator 2 A GIS-based atmospheric dispersion model Computer...
Three Dimensioanl Free Electron Laser Dispersion Relation Including Betatron Oscillations
Chin, Y.H.
2011-01-01T23:59:59.000Z
Three-Dimensional Free Electron Laser Dispersion RelationInternational Free Electron Laser Conference, Santa Fe, NM,International Free Electron Laser Conference, held in Santa
Method for dispersing catalyst onto particulate material
Utz, Bruce R. (Pittsburgh, PA); Cugini, Anthony V. (Pittsburgh, PA)
1992-01-01T23:59:59.000Z
A method for dispersing finely divided catalyst precursors onto the surface of coal or other particulate material includes the steps of forming a wet paste mixture of the particulate material and a liquid solution containing a dissolved transition metal salt, for instance a solution of ferric nitrate. The wet paste mixture is in a state of incipient wetness with all of this solution adsorbed onto the surfaces of the particulate material without the presence of free moisture. On adding a precipitating agent such as ammonia, a catalyst precursor such as hydrated iron oxide is deposited on the surfaces of the coal. The catalyst is activated by converting it to the sulfide form for the hydrogenation or direct liquefaction of the coal.
Dispersion compensation in chirped pulse amplification systems
Bayramian, Andrew James; Molander, William A.
2014-07-15T23:59:59.000Z
A chirped pulse amplification system includes a laser source providing an input laser pulse along an optical path. The input laser pulse is characterized by a first temporal duration. The system also includes a multi-pass pulse stretcher disposed along the optical path. The multi-pass pulse stretcher includes a first set of mirrors operable to receive input light in a first plane and output light in a second plane parallel to the first plane and a first diffraction grating. The pulse stretcher also includes a second set of mirrors operable to receive light diffracted from the first diffraction grating and a second diffraction grating. The pulse stretcher further includes a reflective element operable to reflect light diffracted from the second diffraction grating. The system further includes an amplifier, a pulse compressor, and a passive dispersion compensator disposed along the optical path.
Pless, Robert
Manifold Learning for 4D CT Reconstruction of the Lung Manfred Georg*, Richard Souvenir, Andrew, Canada Andrew.Hope@rmp.uhn.on.ca Abstract Computed Tomography is used to create models of lung dynamics because it provides high contrast images of lung tissue. Creating 4D CT models which capture dynamics
FINITE VOLUME SCHEMES FOR DISPERSIVE WAVE PROPAGATION AND RUNUP
Boyer, Edmond
FINITE VOLUME SCHEMES FOR DISPERSIVE WAVE PROPAGATION AND RUNUP DENYS DUTYKH , THEODOROS KATSAOUNIS to bidirectional nonlinear, dispersive wave propagation in one space dimension. Special emphasis is given require the computation of the wave generation [DD07, KDD07], propagation [TG97], interaction with solid
Atmospheric dispersion index for prescribed burning. Forest Service research paper
Lavdas, L.G.
1986-10-01T23:59:59.000Z
A numerical index that estimates the atmosphere's capacity to disperse smoke from prescribed burning is described. The physical assumptions and mathematical development of the index are given in detail. A preliminary interpretation of dispersion index values is offered. A FORTRAN subroutine package for computing the index is included.
Series evaluation of Tweedie exponential dispersion model densities
Smyth, Gordon K.
of Mathematics and Computing University of Southern Queensland Toowoomba, Qld 4350, Australia Gordon K. Smyth 3052, Australia smyth@wehi.edu.au 23 February 2005 Abstract Exponential dispersion models, which for generalized linear models. The Tweedie families are those exponential dispersion models with power mean
On a nonlocal dispersive equation modeling particle suspensions
Zumbrun, Kevin
On a nonlocal dispersive equation modeling particle suspensions Kevin Zumbrun July, 1996 Abstract: We study a nonlocal, scalar conservation law, u t + ((K a \\Lambda u)u) x = 0, modeling sedimentation, and \\Lambda represents convolution. We show this to be a dispersive regularization of the Hopf equation, u
Manifold, bus support and coupling arrangement for solid oxide fuel cells
Parry, G.W.
1988-04-21T23:59:59.000Z
Individual, tubular solid oxide fuel cells (SOFCs) are assembled into bundles called a module within a housing, with a plurality of modules arranged end-to-end in a linear, stacked configuration called a string. A common set of piping comprised of a suitable high temperature resistant material (1) provides fuel and air to each module housing, (2) serves as electrically conducting buses, and (3) provides structural support for a string of SOFC modules. Ceramic collars are used to connect fuel and air inlet piping to each of the electrodes in an SOFC module and provide (1) electrical insulation for the current carrying bus bars and gas manifolds, (2) damping for the fuel and air inlet piping, and (3) proper spacing between the fuel and air inlet piping to prevent contact between these tubes and possible damage to the SOFC. 11 figs.
Solid oxide fuel cell having monolithic cross flow core and manifolding
Poeppel, R.B.; Dusek, J.T.
1983-10-12T23:59:59.000Z
This invention discloses a monolithic core construction having the flow passageways for the fuel and for the oxidant gases extended transverse to one another, whereby full face core manifolding can be achieved for these gases and their reaction products. The core construction provides that only anode material surround each fuel passageway and only cathode material surround each oxidant passageway, each anode and each cathode further sandwiching at spaced opposing sides electrolyte and interconnect materials to define electrolyte and interconnect walls. Webs of the cathode and anode material hold the electrolyte and interconnect walls spaced apart to define the flow passages. The composite anode and cathode wall structures are further alternately stacked on one another (with the separating electrolyte or interconnect material typically being a single common layer) whereby the fuel passageways and the oxidant passageways are disposed transverse to one another.
The quintic nonlinear Schr\\"odinger equation on three-dimensional Zoll manifolds
Herr, Sebastian
2011-01-01T23:59:59.000Z
Let (M,g) be a three-dimensional smooth compact Riemannian manifold such that all geodesics are simple and closed with a common minimal period, such as the 3-sphere S^3 with canonical metric. In this work the global well-posedness problem for the quintic nonlinear Schr\\"odinger equation i\\partial_t u+\\Delta u=\\pm|u|^4u, u|_{t=0}=u_0 is solved for small initial data u_0 in the energy space H^1(M), which is the scaling-critical space. Moreover, local well-posedness is shown for large data, as well as persistence of higher initial Sobolev regularity. This extends previous results of Burq-G\\'erard-Tzvetkov to the endpoint case.
P. M. Sutter; Tsunefumi Tanaka
2006-10-11T23:59:59.000Z
Although the observed universe appears to be geometrically flat, it could have one of 18 global topologies. A constant-time slice of the spacetime manifold could be a torus, Mobius strip, Klein bottle, or others. This global topology of the universe imposes boundary conditions on quantum fields and affects the vacuum energy density via Casimir effect. In a spacetime with such a nontrivial topology, the vacuum energy density is shifted from its value in a simply-connected spacetime. In this paper, the vacuum expectation value of the stress-energy tensor for a massless scalar field is calculated in all 17 multiply-connected, flat and homogeneous spacetimes with different global topologies. It is found that the vacuum energy density is lowered relative to the Minkowski vacuum level in all spacetimes and that the stress-energy tensor becomes position-dependent in spacetimes that involve reflections and rotations.
Solid oxide fuel cell having monolithic cross flow core and manifolding
Poeppel, Roger B. (Glen Ellyn, IL); Dusek, Joseph T. (Downers Grove, IL)
1984-01-01T23:59:59.000Z
This invention discloses a monolithic core construction having the flow passageways for the fuel and for the oxidant gases extended transverse to one another, whereby full face core manifolding can be achieved for these gases and their reaction products. The core construction provides that only anode material surround each fuel passageway and only cathode material surround each oxidant passageway, each anode and each cathode further sandwiching at spaced opposing sides electrolyte and interconnect materials to define electrolyte and interconnect walls. Webs of the cathode and anode material hold the electrolyte and interconnect walls spaced apart to define the flow passages. The composite anode and cathode wall structures are further alternately stacked on one another (with the separating electrolyte or interconnect material typically being a single common layer) whereby the fuel passageway and the oxidant passageways are disposed transverse to one another.
Dispersion aspects of silicon carbide gelcasting
Bleier, A.
1991-09-01T23:59:59.000Z
The principal objective of this research was to increase the solid loading of silicon carbide (SiC) powder, in an appropriate liquid medium, to a level that is useful for gelcasting technology. A number of factors that determine the maximum concentration of silicon carbide that can be incorporated into a pourable ceramic suspension have been identified. The pH of the system is the most critical processing parameter. Its proper adjustment (pH 11 to 13) allows SiC concentrations exceeding 50%, based on volume, to be routinely achieved without the use of additional dispersing agents. The particle size of SiC was also found to affect the maximum, attainable concentration. The surface area of the powder and the presence of free carbon in the powder, though not significantly influencing the suspension properties, determine the concentration of initiator required to induce polymerization and gelation. SiC specimens have been gelcast for powders in the size range of 0.8 to 8.5 {mu}m; the powders employed contain either {approximately} 0 or 19% carbon by weight. Finally, the generation of bubbles, typically encountered by the use of ammonia to adjust pH has been circumvented by the use of tetramethylammonium hydroxide.
Two-point derivative dispersion relations
Erasmo Ferreira; Javier Sesma
2014-03-24T23:59:59.000Z
A new derivation is given for the representation, under certain conditions, of the integral dispersion relations of scattering theory through local forms. The resulting expressions have been obtained through an independent procedure to construct the real part, and consist of new mathematical structures of double infinite summations of derivatives. In this new form the derivatives are calculated at the generic value of the energy $E$ and separately at the reference point $E=m$ that is the lower limit of the integration. This new form may be more interesting in certain circumstances and directly shows the origin of the difficulties in convergence that were present in the old truncated forms called standard-DDR. For all cases in which the reductions of the double to single sums were obtained in our previous work, leading to explicit demonstration of convergence, these new expressions are seen to be identical to the previous ones. We present, as a glossary, the most simplified explicit results for the DDR's in the cases of imaginary amplitudes of forms $(E/m)^\\lambda[\\ln (E/m)]^n$, that cover the cases of practical interest in particle physics phenomenology at high energies. We explicitly study the expressions for the cases with $\\lambda$ negative odd integers, that require identification of cancelation of singularities, and provide the corresponding final results.
Modelling long-distance seed dispersal in heterogeneous landscapes.
Levey, Douglas, J.; Tewlsbury, Joshua, J.; Bolker, Benjamin, M.
2008-01-01T23:59:59.000Z
1. Long-distance seed dispersal is difficult to measure, yet key to understanding plant population dynamics and community composition. 2. We used a spatially explicit model to predict the distribution of seeds dispersed long distances by birds into habitat patches of different shapes. All patches were the same type of habitat and size, but varied in shape. They occurred in eight experimental landscapes, each with five patches of four different shapes, 150 m apart in a matrix of mature forest. The model was parameterized with smallscale movement data collected from field observations of birds. In a previous study we validated the model by testing its predictions against observed patterns of seed dispersal in real landscapes with the same types and spatial configuration of patches as in the model. 3. Here we apply the model more broadly, examining how patch shape influences the probability of seed deposition by birds into patches, how dispersal kernels (distributions of dispersal distances) vary with patch shape and starting location, and how movement of seeds between patches is affected by patch shape. 4. The model predicts that patches with corridors or other narrow extensions receive higher numbers of seeds than patches without corridors or extensions. This pattern is explained by edgefollowing behaviour of birds. Dispersal distances are generally shorter in heterogeneous landscapes (containing patchy habitat) than in homogeneous landscapes, suggesting that patches divert the movement of seed dispersers, ‘holding’ them long enough to increase the probability of seed defecation in the patches. Dispersal kernels for seeds in homogeneous landscapes were smooth, whereas those in heterogenous landscapes were irregular. In both cases, long-distance (> 150 m) dispersal was surprisingly common, usually comprising approximately 50% of all dispersal events. 5. Synthesis . Landscape heterogeneity has a large influence on patterns of long-distance seed dispersal. Our results suggest that long-distance dispersal events can be predicted using spatially explicit modelling to scale-up local movements, placing them in a landscape context. Similar techniques are commonly used by landscape ecologists to model other types of movement; they offer much promise to the study of seed dispersal.
Leonid Lantsman
2010-08-17T23:59:59.000Z
We intend to show that the vacuum manifold inherent in the Minkowskian non-Abelian model involving Higgs and Yang-Mills BPS vacuum modes and herewith quantized by Dirac can be described with the help of the superselection rules if and only if the "discrete" geometry for this vacuum manifold is assumed (it is just a necessary thing in order justify the Dirac fundamental quantization scheme applied to the mentioned model) and only in the infinitely narrow spatial region of the cylindrical shape where topologically nontrivial vortices are located inside this discrete vacuum manifold.
Confined zone dispersion project. Final technical report
NONE
1994-06-01T23:59:59.000Z
This report describes the performance of the confined zone dispersion (CZD) flue gas desulfurization (FGD) system in removing sulfur dioxide (SO{sub 2}) from flue gas in the coal-fired boiler. The CZD-FGD system, installed at Pennsylvania Electric Company`s (Penelec`s) Seward Power Station, was designed to remove 50% of the SO{sub 2} from one-half of Unit No. 5`s flue gas when the boiler is fired with 1.5% sulfur coal. Section 1 discusses the significance of CZD, the purpose of this report, the history of the project, and the role of DOE in the project, describes the project organization, and lists the six design areas involving proprietary information. Section 2 presents project location, objectives, and phases, and discusses the test program. Section 3 explains the process flow diagram, piping and instrumentation diagrams and operating controls, site plan, equipment layouts, and process equipment. Section 4 provides an integrated discussion of all the test results obtained during the test program, backed by tabulations and graphics. Section 5 describes the testing failures and corrective actions taken. Section 6, reliability/availability/maintainability analysis data of major equipment, covers the following systems: atomizing, sootblowing, lime, flue gas, and controls and instrumentation. Section 7 summarizes the capital cost requirements for the Seward CZD demonstration unit and discusses the capital and operating costs of installing the process at plants with various unit capacities. Section 8 discusses plans to continue the CZD demonstration to achieve longer term continuous operation at SO{sub 2} removals of 50%. Section 9 presents the principal findings of the CZD demonstration and recommends additional testing.
Stability Of Nanoclusters In 14YWT Oxide Dispersion Strengthened...
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Ion-irradiation By Atom Probe Tomography. Abstract: 14YWT oxide dispersion strengthened (ODS) ferritic steel was irradiated with of 5 MeV Ni2+ ions, at 300 °C, 450 °C, and...
The integration of dispersed asylum seekers in Glasgow
Rosenberg, Alexandra
This thesis is an analysis of the integration of dispersed asylum seekers in Glasgow. It is a qualitative case study that uses data from participant observation with community groups, interviews with asylum seekers and those involved in service...
amplified dispersive optical: Topics by E-print Network
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from a finite set. John Jeffers 2011-05-16 5 January 15, 2004 Vol. 29, No. 2 OPTICS LETTERS 201 Generation of 14.8-fs pulses in a spatially dispersed amplifier Materials...
Agents of seed dispersal : animal--zoochary / Wind--anemonochory
Lysakowski, Lukasz Kamil, 1974-
2004-01-01T23:59:59.000Z
Agents of seed dispersal is a project designed to address the increase of environmental degradation, which occurs as a result of the perpetual spread of the asphalt and concrete of the contemporary urban situation. Agents ...
RELIABILITY OF WIND POWER FROM DISPERSED SITES: A PRELIMINARY ASSESSMENT
Kahn, E.
2011-01-01T23:59:59.000Z
PG&E 4:00 p.m. Summer Wind Generator Model Wind Array ELCCexpect from an array of wind generators spread over a largean array of dispersed wind generators will be. wind speed
Testing Dispersal Hypotheses in Foraging Green Sea Turtles (Chelonia
DeSalle, Rob
, population size, geographic distance, natal homing, and ocean currents are hypothesized to affect dispersal, whereas microsatellites uncover similarities to some of the geographically closest populations. Ubatuba and Almofala are mixed stocks, drawn primarily from Ascension, with lesser contributions from Surinam
Colloidal Manipulation of Nanostructures: Stable Dispersion and Self-assembly
Sun, Dazhi
2013-12-16T23:59:59.000Z
This dissertation work addresses two important aspects of nanotechnology - stable dispersion and self-assembly of colloidal nanostructures. Three distinctly different types of nano-scaled materials have been studied: 0-dimensional ZnO quantum dots...
Dispersion interferometer using modulation amplitudes on LHD (invited)
Akiyama, T., E-mail: takiyama@lhd.nifs.ac.jp; Yasuhara, R.; Kawahata, K. [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu 509-5292 (Japan); Okajima, S.; Nakayama, K. [Chubu University, Matsumoto-cho, Kasugai-shi, Aichi 487-8501 (Japan)
2014-11-15T23:59:59.000Z
Since a dispersion interferometer is insensitive to mechanical vibrations, a vibration compensation system is not necessary. The CO{sub 2} laser dispersion interferometer with phase modulations on the Large Helical Device utilizes the new phase extraction method which uses modulation amplitudes and can improve a disadvantage of the original dispersion interferometer: measurement errors caused by variations of detected intensities. The phase variation within ±2 × 10{sup 17} m{sup ?3} is obtained without vibration compensation system. The measured line averaged electron density with the dispersion interferometer shows good agreement with that with the existing far infrared laser interferometer. Fringe jump errors in high density ranging up to 1.5 × 10{sup 20} m{sup ?3} can be overcome by a sufficient sampling rate of about 100 kHz.
RELIABILITY OF WIND POWER FROM DISPERSED SITES: A PRELIMINARY ASSESSMENT
Kahn, E.
2011-01-01T23:59:59.000Z
ON METHODOLOGY: FROM WIND POWER FREQUENCY TO LOSS-OF-LOADJ.P. , "Some Aspects of Wind Power Statistics, " J. of Appl.S£CTION Reliability of Wind Power From Dispersed Sites: A Pr
annular dispersed flow: Topics by E-print Network
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model for overland solute transport Texas A&M University - TxSpace Summary: Using the kinematic-wave overland flow equation and a fractional dispersion-advection equation, a...
advective dispersive formulation: Topics by E-print Network
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model for overland solute transport Texas A&M University - TxSpace Summary: Using the kinematic-wave overland flow equation and a fractional dispersion-advection equation, a...
accentuates transmural dispersion: Topics by E-print Network
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model for overland solute transport Texas A&M University - TxSpace Summary: Using the kinematic-wave overland flow equation and a fractional dispersion-advection equation, a...
Forced-convection, dispersed-flow film boiling
Hynek, Scott Josef
1969-01-01T23:59:59.000Z
This report presents the latest results of an investigation of the characteristics of dispersed flow film boiling. Heat transfer data are presented for vertical upflow of nitrogen in an electrically heated tube, 0.4 in. ...
Dispersion modeling for prediction of emission factors for cattle feedyards
Parnell, Sarah Elizabeth
1994-01-01T23:59:59.000Z
of state air pollution regulatory agencies will require accurate EPA AP-42 emission factors. A protocol was developed so that accurate emission factors can be determined using both source sampling data and dispersion modeling. In this study, an emission...
Hair treatment process providing dispersed colors by light diffraction
Lamartine, Bruce Carvell; Orler, E. Bruce; Sutton, Richard Matthew Charles; Song, Shuangqi
2014-11-11T23:59:59.000Z
Hair was coated with polymer-containing fluid and then hot pressed to form a composite of hair and a polymer film imprinted with a nanopattern. Polychromatic light incident on the nanopattern is diffracted into dispersed colored light.
A dynamic model for the Lagrangian stochastic dispersion coefficient
Pesmazoglou, I.; Navarro-Martinez, S., E-mail: s.navarro@imperial.ac.uk [Department of Mechanical Engineering, Imperial College, London SW7 2AZ (United Kingdom); Kempf, A. M. [Chair of Fluid Dynamics, Institute for Combustion and Gasdynamics and Center for Computational Sciences and Simulation, Universität Duisburg-Essen, Duisburg, 47048 (Germany)] [Chair of Fluid Dynamics, Institute for Combustion and Gasdynamics and Center for Computational Sciences and Simulation, Universität Duisburg-Essen, Duisburg, 47048 (Germany)
2013-12-15T23:59:59.000Z
A stochastic sub-grid model is often used to accurately represent particle dispersion in turbulent flows using large eddy simulations. Models of this type have a free parameter, the dispersion coefficient, which is not universal and is strongly grid-dependent. In the present paper, a dynamic model for the evaluation of the coefficient is proposed and validated in decaying homogeneous isotropic turbulence. The grid dependence of the static coefficient is investigated in a turbulent mixing layer and compared to the dynamic model. The dynamic model accurately predicts dispersion statistics and resolves the grid-dependence. Dispersion statistics of the dynamically calculated constant are more accurate than any static coefficient choice for a number of grid spacings. Furthermore, the dynamic model produces less numerical artefacts than a static model and exhibits smaller sensitivity in the results predicted for different particle relaxation times.
Computation of seismic attenuation and dispersion due to ...
masson@localhost.localdomain (masson)
2006-07-08T23:59:59.000Z
Jun 23, 2006 ... used to model the poroelastic response within such materials are those of Biot ... for the seismic attenuation and dispersion in the special case where the ..... lens embedded in shaly sediments or a fracture embedded in a ...
altered dispersion relations: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
our formalism to the parapositronium two-photon decay. G. Lopez Castro; J. Pestieau; C. Smith; S. Trine 2000-06-01 9 Dispersion relation for anisotropic media CERN Preprints...
Performance Analysis of Dispersed Spectrum Cognitive Radio Systems
Mohammad, Muneer
2011-02-22T23:59:59.000Z
probability of dispersed spectrum cognitive radio systems is derived for two cases: where each channel realization experiences independent and dependent Nakagami-m fading, respectively. In addition, the derivation is extended to include the effects...
Hair treatment process providing dispersed colors by light diffraction
Lamartine, Bruce Carvell; Orler, E. Bruce; Sutton, Richard Matthew Charles; Song, Shuangqi
2013-12-17T23:59:59.000Z
Hair was coated with polymer-containing fluid and then hot pressed to form a composite of hair and a polymer film imprinted with a nanopattern. Polychromatic light incident on the nanopattern is diffracted into dispersed colored light.
Bayesian Network Analysis of Radiological Dispersal Device Acquisitions
Hundley, Grant Richard
2012-02-14T23:59:59.000Z
inflict moderate human casualties and significant economic damage. The vast availability of radioactive sources and the nearly limitless methods of dispersing them demand an inclusive study of the acquisition pathways for an RDD. A complete network...
Gary D. Bourn; Ford A. Phillips; Ralph E. Harris
2005-12-01T23:59:59.000Z
This document provides results and conclusions for Task 15.0--Detailed Analysis of Air Balance & Conceptual Design of Improved Air Manifolds in the ''Technologies to Enhance the Operation of Existing Natural Gas Compression Infrastructure'' project. SwRI{reg_sign} is conducting this project for DOE in conjunction with Pipeline Research Council International, Gas Machinery Research Council, El Paso Pipeline, Cooper Compression, and Southern Star, under DOE contract number DE-FC26-02NT41646. The objective of Task 15.0 was to investigate the perceived imbalance in airflow between power cylinders in two-stroke integral compressor engines and develop solutions via manifold redesign. The overall project objective is to develop and substantiate methods for operating integral engine/compressors in gas pipeline service, which reduce fuel consumption, increase capacity, and enhance mechanical integrity.
Fang, Bess [Department of Physics, Block S12, Faculty of Science, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543 (Singapore); Vignolo, Patrizia; Gattobigio, Mario [Universite de Nice-Sophia Antipolis, Institut Non Lineaire de Nice, CNRS, 1361 route des Lucioles, F-06560 Valbonne (France); Miniatura, Christian [Department of Physics, Block S12, Faculty of Science, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543 (Singapore); Universite de Nice-Sophia Antipolis, Institut Non Lineaire de Nice, CNRS, 1361 route des Lucioles, F-06560 Valbonne (France); Minguzzi, Anna [Universite Grenoble 1, CNRS, LPMMC, UMR5493, Maison des Magisteres, F-38042 Grenoble (France)
2011-08-15T23:59:59.000Z
We present the exact solution for the many-body wavefunction of a one-dimensional mixture of bosons and spin-polarized fermions with equal masses and infinitely strong repulsive interactions under external confinement. Such a model displays a large degeneracy of the ground state. Using a generalized Bose-Fermi mapping, we find the solution for the whole set of ground-state wave functions of the degenerate manifold and we characterize them according to group-symmetry considerations. We find that the density profile and the momentum distribution depends on the symmetry of the solution. By combining the wave functions of the degenerate manifold with suitable symmetry and guided by the strong-coupling form of the Bethe-Ansatz solution for the homogeneous system, we propose an analytic expression for the many-body wave function of the inhomogeneous system which well describes the ground state at finite, large, and equal interaction strengths, as validated by numerical simulations.
Spatially Dispersive Inhomogeneous Electromagnetic Media with Periodic Structure
Gratus, Jonathan
2015-01-01T23:59:59.000Z
Spatially dispersive (also known as non-local) electromagnetic media are considered where the parameters defining the permittivity relation vary periodically. Maxwell's equations give rise to a difference equation corresponding to the Floquet modes. A complete set of approximate solutions is calculated which are valid when the inhomogeneity is small. This is applied to inhomogeneous wire media. A new feature arises when considering spatially dispersive media, that is the existence of coupled modes.
Assessment of gas dispersion in agitated tanks using hydrophones
Sutter, Terry Alan
1986-01-01T23:59:59.000Z
ASSESSMENT OF GAS DISPERSION IN AGITATED TANKS USING HYDROPHONES A Thesis by TERRY ALAN SUTTER Submitted to the Graduate College of Texas ARM University in partial fulfillment of the requirement for the degree of MASTFR OF SCIENCE ofay I...!)sfi Major Subject: Chemical Engineering ASSESSMENT OF GAS DISPERSION IN AGITATED TANKS USING HYDROPHONES A Thesis by TERRY ALAN SUTTER Approved as to style and content by: Gary B. Tatterson (Chairinan of Committee) Gerald L. orrison (Xieniber) C...
Christopher J. Fama; Susan M. Scott
1994-06-21T23:59:59.000Z
The {\\em abstract boundary\\/} (or {\\em {\\em a\\/}-boundary\\/}) of Scott and Szekeres \\cite{Scott94} constitutes a ``boundary'' to any $n$-dimensional, paracompact, connected, Hausdorff, $C^\\infty$-manifold (without a boundary in the usual sense). In general relativity one deals with a {\\em space-% time\\/} $(\\cM,g)$ (a 4-dimensional manifold $\\cM$ with a Lorentzian metric $g$), together with a chosen preferred class of curves in $\\cM$. In this case the {\\em a\\/}-boundary points may represent ``singularities'' or ``points at infinity''. Since the {\\em a\\/}-boundary itself, however, does not depend on the existence of further structure on the manifold such as a Lorentzian metric or connection, it is possible for it to be used in many contexts. In this paper we develop some purely topological properties of abstract boundary sets and abstract boundary points ({\\em a\\/}-boundary points). We prove, amongst other things, that compactness is invariant under boundary set equivalence, and introduce another invariant concept ({\\em isolation\\/}), which encapsulates the notion that a boundary set is ``separated'' from other boundary points of the same embedding. ....... [The abstract continues in paper proper - truncated to fit here.
The landscape of G-structures in eight-manifold compactifications of M-theory
Babalic, Elena Mirela
2015-01-01T23:59:59.000Z
We consider spaces of "virtual" constrained generalized Killing spinors, i.e. spaces of Majorana spinors which correspond to "off-shell" $s$-extended supersymmetry in compactifications of eleven-dimensional supergravity based on eight-manifolds $M$. Such spaces naturally induce two stratifications of $M$, called the chirality and stabilizer stratification. For the case $s=2$, we describe the former using the canonical Whitney stratification of a three-dimensional semi-algebraic set ${\\cal R}$. We also show that the stabilizer stratification coincides with the rank stratification of a cosmooth generalized distribution ${\\cal D}_0$ and describe it explicitly using the Whitney stratification of a four-dimensional semi-algebraic set $\\mathfrak{P}$. The stabilizer groups along the strata are isomorphic with $\\mathrm{SU}(2)$, $\\mathrm{SU}(3)$, $\\mathrm{G}_2$ or $\\mathrm{SU}(4)$, where $\\mathrm{SU(2)}$ corresponds to the open stratum, which is generically non-empty. We also determine the rank stratification of a lar...
The landscape of G-structures in eight-manifold compactifications of M-theory
Elena Mirela Babalic; Calin Iuliu Lazaroiu
2015-05-09T23:59:59.000Z
We consider spaces of "virtual" constrained generalized Killing spinors, i.e. spaces of Majorana spinors which correspond to "off-shell" $s$-extended supersymmetry in compactifications of eleven-dimensional supergravity based on eight-manifolds $M$. Such spaces naturally induce two stratifications of $M$, called the chirality and stabilizer stratification. For the case $s=2$, we describe the former using the canonical Whitney stratification of a three-dimensional semi-algebraic set ${\\cal R}$. We also show that the stabilizer stratification coincides with the rank stratification of a cosmooth generalized distribution ${\\cal D}_0$ and describe it explicitly using the Whitney stratification of a four-dimensional semi-algebraic set $\\mathfrak{P}$. The stabilizer groups along the strata are isomorphic with $\\mathrm{SU}(2)$, $\\mathrm{SU}(3)$, $\\mathrm{G}_2$ or $\\mathrm{SU}(4)$, where $\\mathrm{SU(2)}$ corresponds to the open stratum, which is generically non-empty. We also determine the rank stratification of a larger generalized distribution ${\\cal D}$ which turns out to be integrable in the case of compactifications down to $\\mathrm{AdS}_3$.
Space-Time as an Orderparameter Manifold in Random Networks and the Emergence of Physical Points
Manfred Requardt
1999-02-11T23:59:59.000Z
In the following we are going to describe how macroscopic space-time is supposed to emerge as an orderparameter manifold or superstructure floating in a stochastic discrete network structure. As in preceeding work (mentioned below), our analysis is based on the working philosophy that both physics and the corresponding mathematics have to be genuinely discrete on the primordial (Planck scale) level. This strategy is concretely implemented in the form of cellular networks and random graphs. One of our main themes is the development of the concept of physical (proto)points as densely entangled subcomplexes of the network and their respective web, establishing something like (proto)causality. It max perhaps be said that certain parts of our programme are realisations of some old and qualitative ideas of Menger and more recent ones sketched by Smolin a couple of years ago. We briefly indicate how this two-story-concept of space-time can be used to encode the (at least in our view) existing non-local aspects of quantum theory without violating macroscopic space-time causality!
Quantization of the relativistic fluid in physical phase space on Kaehler manifolds
Holender, L.; Vancea, I. V. [Departamento de Fisica, Universidade Federal Rural do Rio de Janeiro (UFRRJ), Cx. Postal 23851, 23890-000 Seropedica (Brazil); Santos, M. A. [Departamento de Fisica e Quimica, Universidade Federal do Espirito Santo (UFES), Avenida Fernando Ferarri S/N-Goiabeiras, 29060-900 Vitoria (Brazil)
2008-02-15T23:59:59.000Z
We discuss the quantization of a class of relativistic fluid models defined in terms of one real and two complex conjugate potentials with values on a Kaehler manifold, and parametrized by the Kaehler potential K(z,z) and a real number {lambda}. In the Hamiltonian formulation, the canonical conjugate momenta of the potentials are subjected to second-class constraints which allow us to apply the symplectic projector method in order to find the physical degrees of freedom and the physical Hamiltonian. We construct the quantum theory for that class of models by employing the canonical quantization methods. We also show that a semiclassical theory in which the Kaehler and the complex potentials are not quantized has a highly degenerate vacuum. We define and compute the quantum topological number (quantum linking number) operator which has nonvanishing contributions from the Kaehler and complex potentials only. Also, we show that the vacuum and the states formed by tensoring the number operators eigenstates have zero linking number, and show that linear combinations of the tensor product of number operators eigenstates which have the form of entangled states have nonzero linking number.
Manifold, bus support and coupling arrangement for solid oxide fuel cells
Parry, Gareth W. (East Windsor, CT)
1989-01-01T23:59:59.000Z
Individual, tubular solid oxide fuel cells (SOFCs) are assembled into bundles called a module within a housing, with a plurality of modules arranged end-to-end in a linear, stacked configuration called a string. A common set of piping comprised of a suitable high temperture resistant material (1) provides fuel and air to each module housing, (2) serves as electrically conducting buses, and (3) provides structural support for a string of SOFC modules. The piping thus forms a manfold for directing fuel and air to each module in a string and makes electrical contact with the module's anode and cathode to conduct the DC power generated by the SOFC. The piping also provides structureal support for each individual module and maintains each string of modules as a structurally integral unit for ensuring high strength in a large 3-dimensional array of SOFC modules. Ceramic collars are used to connect fuel and air inlet piping to each of the electrodes in an SOFC module and provide (1) electrical insulation for the current carrying bus bars and gas manifolds, (2) damping for the fuel and air inlet piping, and (3) proper spacing between the fuel and air inlet piping to prevent contact between these tubes and possible damage to the SOFC.
System and method for detection of dispersed broadband signals
Qian, Shie (Austin, TX); Dunham, Mark E. (Los Alamos, NM)
1999-06-08T23:59:59.000Z
A system and method for detecting the presence of dispersed broadband signals in real time. The present invention utilizes a bank of matched filters for detecting the received dispersed broadband signals. Each matched filter uses a respective robust time template that has been designed to approximate the dispersed broadband signals of interest, and each time template varies across a spectrum of possible dispersed broadband signal time templates. The received dispersed broadband signal x(t) is received by each of the matched filters, and if one or more matches occurs, then the received data is determined to have signal data of interest. This signal data can then be analyzed and/or transmitted to Earth for analysis, as desired. The system and method of the present invention will prove extremely useful in many fields, including satellite communications, plasma physics, and interstellar research. The varying time templates used in the bank of matched filters are determined as follows. The robust time domain template is assumed to take the form w(t)=A(t)cos{2.phi.(t)}. Since the instantaneous frequency f(t) is known to be equal to the derivative of the phase .phi.(t), the trajectory of a joint time-frequency representation of x(t) is used as an approximation of .phi.'(t).
System and method for detection of dispersed broadband signals
Qian, S.; Dunham, M.E.
1999-06-08T23:59:59.000Z
A system and method for detecting the presence of dispersed broadband signals in real time are disclosed. The present invention utilizes a bank of matched filters for detecting the received dispersed broadband signals. Each matched filter uses a respective robust time template that has been designed to approximate the dispersed broadband signals of interest, and each time template varies across a spectrum of possible dispersed broadband signal time templates. The received dispersed broadband signal x(t) is received by each of the matched filters, and if one or more matches occurs, then the received data is determined to have signal data of interest. This signal data can then be analyzed and/or transmitted to Earth for analysis, as desired. The system and method of the present invention will prove extremely useful in many fields, including satellite communications, plasma physics, and interstellar research. The varying time templates used in the bank of matched filters are determined as follows. The robust time domain template is assumed to take the form w(t)=A(t)cos[l brace]2[phi](t)[r brace]. Since the instantaneous frequency f(t) is known to be equal to the derivative of the phase [phi](t), the trajectory of a joint time-frequency representation of x(t) is used as an approximation of [phi][prime](t). 10 figs.
Method of Manufacturing Micro-Disperse Particles of Sodium Borohydride
Kravitz, Stanley H. (Placitas, NM); Hecht, Andrew M. (Sandia Park, NM); Sylwester. Alan P. (Albuquerque, NM); Bell, Nelson S. (Albuquerque, NM)
2008-09-23T23:59:59.000Z
A compact solid source of hydrogen gas, where the gas is generated by contacting water with micro-disperse particles of sodium borohydride in the presence of a catalyst, such as cobalt or ruthenium. The micro-disperse particles can have a substantially uniform diameter of 1-10 microns, and preferably about 3-5 microns. Ruthenium or cobalt catalytic nanoparticles can be incorporated in the micro-disperse particles of sodium borohydride, which allows a rapid and complete reaction to occur without the problems associated with caking and scaling of the surface by the reactant product sodium metaborate. A closed loop water management system can be used to recycle wastewater from a PEM fuel cell to supply water for reacting with the micro-disperse particles of sodium borohydride in a compact hydrogen gas generator. Capillary forces can wick water from a water reservoir into a packed bed of micro-disperse fuel particles, eliminating the need for using an active pump.
The concentration-velocity dispersion relation in galaxy groups
Andreas Faltenbacher; William G. Mathews
2007-06-08T23:59:59.000Z
Based on results from cold dark matter N-body simulations we develop a dynamical model for the evolution of subhaloes within host haloes of galaxy groups. Only subhaloes more massive than 5 times 10^8 M_{sol} at the time of accretion are examined because they are massive enough to possibly host luminous galaxies. As they orbit within a growing host potential the subhaloes are subject to tidal stripping and dynamical friction. We consider groups of equal mass (M_{vir} = 3.9 times 10^{13} M_{sol}) at redshift z=0 but with different concentrations associated with different formation times. We investigate the variation of subhaloe (or satellite galaxy) velocity dispersion with host concentration and/or formation time. In agreement with the Jeans equation the velocity dispersion of subhaloes increases with the host concentration. Between concentrations ~5 and ~20 the subhaloe velocity dispersions increase by ~25 per cent. By applying a simplified tidal disruption criterion, i.e. rejection of all subhaloes with a tidal truncation radius below 3 kpc at z=0, the central velocity dispersion of 'surviving' subhaloes increases substantially for all concentrations. The enhanced central velocity dispersion among surviving subhaloes is caused by a lack of slow tangential motions. Additionally, we present a fitting formula for the velocity anisotropy parameter \\beta(r) which does not depend on concentration if the group-centric distances are scaled by r_s, the characteristic radius of the NFW-profile.
Can dispersal mode predict corridor effects on plant parasites?
Sullivan, Lauren, L.; Johnson, Brenda, L.; Brudvig, Lars, A.; Haddad, Nick, M.
2011-08-01T23:59:59.000Z
Habitat corridors, a common management strategy for increasing connectivity in fragmented landscapes, have experimentally validated positive influences on species movement and diversity. However, long-standing concerns that corridors could negatively impact native species by spreading antagonists, such as disease, remain largely untested. Using a large-scale, replicated experiment, we evaluated whether corridors increase the incidence of plant parasites. We found that corridor impacts varied with parasite dispersal mode. Connectivity provided by corridors increased incidence of biotically dispersed parasites (galls on Solidago odora) but not of abiotically dispersed parasites (foliar fungi on S. odora and three Lespedeza spp.). Both biotically and abiotically dispersed parasites responded to edge effects, but the direction of responses varied across species. Although our results require additional tests for generality to other species and landscapes, they suggest that, when establishing conservation corridors, managers should focus on mitigating two potential negative effects: the indirect effects of narrow corridors in creating edges and direct effects of corridors in enhancing connectivity of biotically dispersed parasites.
Grant L. Hawkes; James E. O'Brien; Greg Tao
2011-11-01T23:59:59.000Z
A three-dimensional computational fluid dynamics (CFD) electrochemical model has been created to model high-temperature electrolysis cell performance and steam electrolysis in an internally manifolded planar solid oxide electrolysis cell (SOEC) stack. This design is being evaluated at the Idaho National Laboratory for hydrogen production from nuclear power and process heat. Mass, momentum, energy, and species conservation and transport are provided via the core features of the commercial CFD code FLUENT. A solid-oxide fuel cell (SOFC) model adds the electrochemical reactions and loss mechanisms and computation of the electric field throughout the cell. The FLUENT SOFC user-defined subroutine was modified for this work to allow for operation in the SOEC mode. Model results provide detailed profiles of temperature, operating potential, steam-electrode gas composition, oxygen-electrode gas composition, current density and hydrogen production over a range of stack operating conditions. Single-cell and five-cell results will be presented. Flow distribution through both models is discussed. Flow enters from the bottom, distributes through the inlet plenum, flows across the cells, gathers in the outlet plenum and flows downward making an upside-down ''U'' shaped flow pattern. Flow and concentration variations exist downstream of the inlet holes. Predicted mean outlet hydrogen and steam concentrations vary linearly with current density, as expected. Effects of variations in operating temperature, gas flow rate, oxygen-electrode and steam-electrode current density, and contact resistance from the base case are presented. Contour plots of local electrolyte temperature, current density, and Nernst potential indicate the effects of heat transfer, reaction cooling/heating, and change in local gas composition. Results are discussed for using this design in the electrolysis mode. Discussion of thermal neutral voltage, enthalpy of reaction, hydrogen production, cell thermal efficiency, cell electrical efficiency, and Gibbs free energy are discussed and reported herein.
Short-range atmospheric dispersion of carbon dioxide
Cortis, A.; Oldenburg, C.M.
2009-11-01T23:59:59.000Z
We present a numerical study aimed at quantifying the effects of concentration-dependent density on the spread of a seeping plume of CO{sub 2} into the atmosphere such as could arise from a leaking geologic carbon sequestration site. Results of numerical models can be used to supplement field monitoring estimates of CO{sub 2} seepage flux by modelling transport and dispersion between the source emission and concentration-measurement points. We focus on modelling CO{sub 2} seepage dispersion over relatively short distances where density effects are likely to be important. We model dense gas dispersion using the steady-state Reynolds-averaged Navier-Stokes equations with density dependence in the gravity term. Results for a two-dimensional system show that a density dependence emerges at higher fluxes than prior estimates. A universal scaling relation is derived that allows estimation of the flux from concentrations measured downwind and vice versa.
Fractional power-law spatial dispersion in electrodynamics
Tarasov, Vasily E., E-mail: tarasov@theory.sinp.msu.ru [Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow 119991 (Russian Federation); Departamento de Análisis Matemático, Universidad de La Laguna, 38271 La Laguna, Tenerife (Spain); Trujillo, Juan J., E-mail: jtrujill@ullmat.es [Departamento de Análisis Matemático, Universidad de La Laguna, 38271 La Laguna, Tenerife (Spain)
2013-07-15T23:59:59.000Z
Electric fields in non-local media with power-law spatial dispersion are discussed. Equations involving a fractional Laplacian in the Riesz form that describe the electric fields in such non-local media are studied. The generalizations of Coulomb’s law and Debye’s screening for power-law non-local media are characterized. We consider simple models with anomalous behavior of plasma-like media with power-law spatial dispersions. The suggested fractional differential models for these plasma-like media are discussed to describe non-local properties of power-law type. -- Highlights: •Plasma-like non-local media with power-law spatial dispersion. •Fractional differential equations for electric fields in the media. •The generalizations of Coulomb’s law and Debye’s screening for the media.
Polydispersity analysis of Taylor dispersion data: the cumulant method
Luca Cipelletti; Jean-Philippe Biron; Michel Martin; Hervé Cottet
2014-08-26T23:59:59.000Z
Taylor dispersion analysis is an increasingly popular characterization method that measures the diffusion coefficient, and hence the hydrodynamic radius, of (bio)polymers, nanoparticles or even small molecules. In this work, we describe an extension to current data analysis schemes that allows size polydispersity to be quantified for an arbitrary sample, thereby significantly enhancing the potentiality of Taylor dispersion analysis. The method is based on a cumulant development similar to that used for the analysis of dynamic light scattering data. Specific challenges posed by the cumulant analysis of Taylor dispersion data are discussed, and practical ways to address them are proposed. We successfully test this new method by analyzing both simulated and experimental data for solutions of moderately polydisperse polymers and polymer mixtures.
New ceramics containing dispersants for improved fracture toughness
Nevitt, M.V.; Aldred, A.T.; Chan, Sai-Kit
1985-07-01T23:59:59.000Z
The invention is a ceramic composition containing a new class of dispersant for hindering crack propagation by means of one or more energy-dissipative mechanisms. The composition is composed of a ceramic matrix with dispersed particles of a transformation-prone rare-earth niobate, tantalate or mixtures of these with each other and/or with a rare-earth vanadate. The dispersants, having a generic composition tRBO/sub 4/, where R is a rare-earth element, B if Nb or Ta and O is oxygen, are mixed in powder form with a powder of the matrix ceramic and sintered to produce a ceramic form or body. The crack-hindering mechanisms operates to provide improved performance over a wide range of temperature and operating conditions.
Scattering approach to dispersive atom-surface interactions
Dalvit, Diego [Los Alamos National Laboratory; Messina, Riccardo [LAB KASTLER BROSSEL; Maia Neto, Paulo [INSTITUTO DE FISICA UFRJ; Lambrecht, Astrid [LAB KASTLER BROSSEL; Reynaud, Serge [LAB KASTLER BROSSEL
2009-01-01T23:59:59.000Z
We develop the scattering approach for the dispersive force on a ground state atom on top of a corrugated surface. We present explicit results to first order in the corrugation amplitude. A variety of analytical results are derived in different limiting cases, including the van der Waals and Casimir-Polder regimes. We compute numerically the exact first-order dispersive potential for arbitrary separation distances and corrugation wavelengths, for a Rubidium atom on top of a silicon or gold corrugated surface. We consider in detail the correction to the proximity force approximation, and present a very simple approximation algorithm for computing the potential.
Stellar Velocity Dispersion of the Leo A Dwarf Galaxy
Warren R. Brown; Margaret J. Geller; Scott J. Kenyon; Michael J. Kurtz
2007-05-08T23:59:59.000Z
We measure the first stellar velocity dispersion of the Leo A dwarf galaxy, \\sigma = 9.3 +- 1.3 km/s. We derive the velocity dispersion from the radial velocities of ten young B supergiants and two HII regions in the central region of Leo A. We estimate a projected mass of 8 +- 2.7 x10^7 solar masses within a radius of 2 arcmin, and a mass to light ratio of at least 20 +- 6 M_sun/L_sun. These results imply Leo A is at least ~80% dark matter by mass.
Fractional Power-Law Spatial Dispersion in Electrodynamics
Tarasov, Vasily E
2015-01-01T23:59:59.000Z
Electric fields in non-local media with power-law spatial dispersion are discussed. Equations involving a fractional Laplacian in the Riesz form that describe the electric fields in such non-local media are studied. The generalizations of Coulomb's law and Debye's screening for power-law non-local media are characterized. We consider simple models with anomalous behavior of plasma-like media with power-law spatial dispersions. The suggested fractional differential models for these plasma-like media are discussed to describe non-local properties of power-law type.
Thomas Laetsch
2013-05-17T23:59:59.000Z
This paper gives a rigorous interpretation of a Feynman path integral on a Riemannian manifold M with non-positive sectional curvature. A $L^2$ Riemannian metric $G_P$ is given on the space of piecewise geodesic paths $H_P(M)$ adapted to the partition $P$ of $[0,1]$, whence a finite-dimensional approximation of Wiener measure is developed. It is proved that, as $mesh(P) \\to 0$, the approximate Wiener measure converges in a $L^1$ sense to the measure $e^{-\\frac{2 + \\sqrt{3}}{20\\sqrt{3}} \\int_0^1 Scal(\\sigma(s)) ds} d\
Analysis of Tracer Dispersion During a Prescribed Forest Burn
Collins, Gary S.
. Additionally, a sulfur hexafluoride (SF6) tracer dispersion test was conducted by releasing SF6 from a line source within the burn and measuring SF6 concentrations at the supertower. Supertower Instrumentation (TGAPS) connected to a CO2 closed path Licor LI-6262 and a SF6 detector (7 inlet locations) ·Cambell CSAT
Distinct spinon and holon dispersions in photoemission spectral functions from
Loss, Daniel
ARTICLES Distinct spinon and holon dispersions in photoemission spectral functions from one particles) called spinons and holons. Experimentalists have long sought to verify this effect. Angle quasiparticle peak splits into a spinonÂholon two-peak- like structure. Despite extensive ARPES experiments
Effect of Dispersant on Asphaltene Suspension Dynamics: Aggregation and Sedimentation
Firoozabadi, Abbas
processes, most involving scat- tering, either dynamic light scattering, static light scattering, or neutron on this aggregation behavior through the use of dynamic light scattering, showing that both the amount of dispersant asphaltene suspensions. The light scattering results match well with those obtained through the macroscopic
Combined dispersive/interference spectroscopy for producing a vector spectrum
Erskine, David J. (Oakland, CA)
2002-01-01T23:59:59.000Z
A method of measuring the spectral properties of broadband waves that combines interferometry with a wavelength disperser having many spectral channels to produce a fringing spectrum. Spectral mapping, Doppler shifts, metrology of angles, distances and secondary effects such as temperature, pressure, and acceleration which change an interferometer cavity length can be measured accurately by a compact instrument using broadband illumination. Broadband illumination avoids the fringe skip ambiguities of monochromatic waves. The interferometer provides arbitrarily high spectral resolution, simple instrument response, compactness, low cost, high field of view and high efficiency. The inclusion of a disperser increases fringe visibility and signal to noise ratio over an interferometer used alone for broadband waves. The fringing spectrum is represented as a wavelength dependent 2-d vector, which describes the fringe amplitude and phase. Vector mathematics such as generalized dot products rapidly computes average broadband phase shifts to high accuracy. A Moire effect between the interferometer's sinusoidal transmission and the illumination heterodynes high resolution spectral detail to low spectral detail, allowing the use of a low resolution disperser. Multiple parallel interferometer cavities of fixed delay allow the instantaneous mapping of a spectrum, with an instrument more compact for the same spectral resolution than a conventional dispersive spectrometer, and not requiring a scanning delay.
High-index-core Bragg fibers: dispersion Juan A. Monsoriu
Fernández de Córdoba, Pedro
. P. Yeh, A. Yariv, and E. Marom, "Theory of Bragg fiber," J. Opt. Soc. Am. 68, 1196-1201 (1978). 4. Y. Xu, G.X. Ouyang, R.K. Lee, and A. Yariv, "Asymptotic Matrix Theory of Bragg Fibers," J. LightwaveHigh-index-core Bragg fibers: dispersion properties Juan A. Monsoriu Departamento de Física
Physicalbiological coupling in spore dispersal of kelp forest macroalgae
Washburn, Libe
PhysicalÂbiological coupling in spore dispersal of kelp forest macroalgae $ Brian Gaylorda produced by macroalgae that reside in kelp forests are complicated and laced with feedbacks. Here we before they contact the seafloor. Morphologies and material properties of canopy forming kelps may also
Weakly dispersive hydraulic flows in a contraction --Nonlinear stability analysis
Ee, Bernard Kuowei
Weakly dispersive hydraulic flows in a contraction -- Nonlinear stability analysis Bernard K. Ee hydraulic solutions of the forced Korteweg de-Vries equation is investigated here. For numerical convenience is destabilized by a hydraulic instability in which superexponential growth occurs prior to satura- tion
Development oxide dispersion strengthened ferritic steels for fusion
Mukhopadhyay, D.K.; Froes, F.H.; Gelles, D.S. [Pacific Northwest National Lab., Richland, WA (United States)
1997-04-01T23:59:59.000Z
Uniaxial tension creep response is reported for an oxide dispersion strengthened (ODS) steel, Fe-13.5Cr-2W-0.5Ti-0.25 Y{sub 2}O{sub 3} (in weight percent) manufactured using the mechanical alloying process. Acceptable creep response is obtained at 900{degrees}C.
Electrical properties of dispersions of graphene in mineral oil
Monteiro, O. R., E-mail: othon.monteiro@bakerhughes.com [Baker Hughes, 14990 Yorktown Plaza Dr., Houston, Texas 77040 (United States)
2014-02-03T23:59:59.000Z
Dispersions of graphene in mineral oil have been prepared and electrical conductivity and permittivity have been measured. The direct current (DC) conductivity of the dispersions depends on the surface characteristics of the graphene platelets and followed a percolation model with a percolation threshold ranging from 0.05 to 0.1?wt. %. The difference in DC conductivities can be attributed to different states of aggregation of the graphene platelets and to the inter-particle electron transfer, which is affected by the surface radicals. The frequency-dependent conductivity (?(?)) and permittivity (?(?)) were also measured. The conductivity of dispersions with particle contents much greater than the percolation threshold remains constant and equal to the DC conductivity at low frequencies ? with and followed a power-law ?(?)???{sup s} dependence at very high frequencies with s?0.9. For dispersions with graphene concentration near the percolation threshold, a third regime was displayed at intermediate frequencies indicative of interfacial polarization consistent with Maxwell-Wagner effect typically observed in mixtures of two (or more) phases with very distinct electrical and dielectric properties.
Heavy tailed K distributions imply a fractional advection dispersion equation
Meerschaert, Mark M.
Dispersion Equation (FADE) to model contaminant transport in porous media. This equation characterizes, and Particle Jumps Equations of contaminant transport in porous media are based on assumptions about hydraulic governing groundwater flow (e.g., Freeze and Cherry, 1979): h K v - = (1) where v is average velocity
Oxide dispersion strengthening of nickel electrodeposits for microsystem applications.
Janek, Richard P. (Owens Technology Inc., Palo Alto, CA); Kotula, Paul Gabriel; Buchheit, Thomas Edward; Michael, R. P.; Goods, Steven Howard
2003-11-01T23:59:59.000Z
Oxide dispersion strengthened nickel (ODS-Ni) electrodeposits were fabricated to net shape in a nickel sulfamate bath using the LIGA process. A 20 g/l charge of 10 nm Al{sub 2}O{sub 3} powder was suspended in the bath during electrodeposition to produce specimens containing an approximately 0.001-0.02 volume fraction dispersion of the alumina particulate. Mechanical properties are compared to baseline specimens fabricated using an identical sulfamate bath chemistry without the Al{sub 2}O{sub 3} powder charge. Results reveal that the as-deposited ODS-Ni exhibited significantly higher yield strength and ultimate tensile strength than the baseline material. This increase in as-deposited strength is attributed to Orowan strengthening. The ODS-Ni also showed improved retention of room temperature strength after annealing over a range of temperatures up to 600 C. Microscopy revealed that this resistance to anneal softening was due to an inhibition of grain growth in the presence of the oxide dispersion. Nanoindentation measurements revealed that the properties of the dispersion strengthened deposit were uniform through its thickness, even in narrow, high aspect ratio structures. At elevated temperatures, the strength of the ODS-Ni was approximately three times greater than that of the baseline material although with a significant reduction in hot ductility.
THE EFFECT OF TRANSVERSE MIXING ON TRACER DISPERSION
Stanford University
Hardware Data Acquisition And Analysis Software Experimental Procedure Analysis Procedure Results: Taylor. The theoretical response for linear Taylor dispersion was matched to the data to determine the non-linear Of Tracer Valve Constant-pressure Reservoir Design Schematic Drawing Of Electrode Circuit Results: Run 16
Refraction of dispersive shock waves , V.V. Khodorovskii 2
a dispersive counterpart of the classical gas dynamics problem of the interaction of a shock wave investigations, most notably in Bose-Einstein condensates (BECs) (see, e.g., [8, 32, 6]), where these waves problem involves complicated analysis of nonlinear multiphase wavetrains (see e.g. [22] for the Kd
air pollution dispersion: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
air pollution dispersion First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Environmental Pollution Air...
Permeability and Dispersion Coefficients in Rocks with Fracture Network - 12140
Lee, C.K.; Htway, M.Z. [Handong Global University, 3 Namsong-ri, Heunghae-eub, Buk-gu, Pohang, Kyungbuk, 791-708 (Korea, Republic of); Yim, S.P. [Korea Atomic Energy Research Institute, P.O.Box 150, Yusong, Daejon, 305-600 (Korea, Republic of)
2012-07-01T23:59:59.000Z
Fluid flow and solute transport are considered for a rock medium with a fracture network with regard to the effective permeability and the dispersion coefficients. To investigate the effects of individual fractures a three-fracture system is chosen in which two are parallel and the third one connects the two at different angles. Specifically the micro-cell boundary-value problems(defined through multiple scale analysis) are solved numerically by using finite elements to calculate the permeability and dispersion coefficients. It is shown that the permeability depends significantly on the pattern of the fracture distribution and the dispersion coefficient is influenced by both the externally imposed pressure gradient (which also reflects the flow field) and the direction of the gradient of solute concentration on the macro-scale. From the calculations of the permeability and dispersion coefficients for solute in a rock medium with a fracture network the following conclusions are drawn. 1. The permeability of fractured medium depends on the primary orientation of the fracture network and is influenced by the connecting fractures in the medium. 2. The cross permeability, e.g., permeability in the direction normal to the direction of the external pressure gradient is rather insensitive to the orientation of the fracture network. 3. Calculation of permeability is most efficiently achieved with optimal discretization across individual fractures and is rather insensitive to the discretization along the fracture.. 4. The longitudinal dispersion coefficient Dxx of a fractured medium depends on both the macro-scale concentration gradient and the direction of the flow (pressure gradient). Hence both features must be considered when investigating solute transport in a fractured medium. (authors)
amine-terminated water-dispersible fept: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
amine-terminated water-dispersible fept First Page Previous Page 1 2 3 4 5 6 Next Page Last Page Topic Index 1 Water Dispersible Silanes for Wettability Modification of Polysilicon...
Review of the ENSR Report Titled "Update 1 to: A Dispersion Modeling...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
"Update 1 to: A Dispersion Modeling Analysis of Downwash from Mirant's Potomac River Power Plant" Review of the ENSR Report Titled "Update 1 to: A Dispersion Modeling Analysis of...
Etika, Krishna
2012-02-14T23:59:59.000Z
-controlled dispersion of carbon nanotubes could have a variety of applications in nanoelectronics, sensing, and drug and gene delivery systems. Furthermore, this dissertation also contains a published study focused on controlling the dispersion state of carbon black (CB...
Energy Dispersed Large Data Wave Maps in 2 + 1 Dimensions
Sterbenz, Jacob; Tataru, Daniel
2010-01-01T23:59:59.000Z
of Finite S Norm Wave-Maps and Energy Dispersion 10.1renormalization of large energy wave maps. In: Journées “of Finite S Norm Wave-Maps and Energy Dispersion In this
Highly dispersed carbon nanotubes in organic media for polymer:fullerene photovoltaic devices
Hong, Soon Hyung
Highly dispersed carbon nanotubes in organic media for polymer:fullerene photovoltaic devices Gwang photovoltaic device are fabricated using homogeneously dispersed carbon nanotubes (CNTs) in a polymer. All rights reserved. 1. Introduction Organic photovoltaic (OPV) materials promise the production
Heat transfer to impacting drops and post critical heat flux dispersed flow
Kendall, Gail E.
1978-01-01T23:59:59.000Z
Heat transfer to drops impacting on a hot surface is examined in context of dispersions of flowing, boiling fluids. The liquid contribution to heat transfer from a hot tube to a two-phase dispersion is formulated in terms ...
Critique of Burnett-Frind dispersion tensor for axisymmetric porous media
Lichtner, Peter C [Los Alamos National Laboratory; Kelkar, Sharad [Los Alamos National Laboratory; Robinson, Bruce A [Los Alamos National Laboratory
2008-01-01T23:59:59.000Z
This technical note provides a critique of the Burnett and Frind (1987) dispersion tensor for porous media with axial symmetry based on a previous publication by the authors (Lichtner et aI., 2002). In this work a new approach is used based on unit eigenvectors which simplifies the analysis. It is demonstrated that the Burnett-Frind dispersion tensor, although acceptable for small values of the vertical velocity, produces the incorrect behavior for both longitudinal and transverse dispersivity as the flow velocity varies from parallel to perpendicular to the axis of symmetry. A new form of the dispersion tensor is derived for axially symmetric porous media involving four dispersivity coefficients corresponding to longitudinal and transverse dispersion in horizontal and vertical directions, defined as perpendicular and parallel to the axis of symmetry, respectively. This new dispersion tensor corrects two fundamental problems with the dispersion tensor proposed by Burnett and Frind (1987) for axial symmetric media.
On-board Measurement of NO and NO2 using Non-dispersive Ultraviolet...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
board Measurement of NO and NO2 using Non-dispersive Ultraviolet (NDUV) Spectroscopy On-board Measurement of NO and NO2 using Non-dispersive Ultraviolet (NDUV) Spectroscopy...
CFD Simulations of Joint Urban Atmospheric Dispersion Field Study
Lee, R; Humphreys III, T; Chan, S
2004-06-17T23:59:59.000Z
The application of Computational Fluid Dynamics (CFD) to the understanding of urban wind flow and dispersion processes has gained increasing attention over recent years. While many of the simpler dispersion models are based on a set of prescribed meteorology to calculate dispersion, the CFD approach has the ability of coupling the wind field to dispersion processes. This has distinct advantages when very detailed results are required, such as for the case where the releases occur around buildings and within urban areas. CFD also has great flexibility as a testbed for turbulence models, which has important implications for atmospheric dispersion problems. In the spring of 2003, a series of dispersion field experiments (Joint Urban 2003) were conducted at Oklahoma City (Allwine, et. al, 2004). These experiments were complimentary to the URBAN 2000 field studies at Salt Lake City (Shinn, et. al, 2000) in that they will provide a second set of comprehensive field data for evaluation of CFD as well as for other dispersion models. In contrast to the URBAN 2000 experiments that were conducted entirely at night, these new field studies took place during both daytime and nighttime thus including the possibility of convective as well as stable atmospheric conditions. Initially several CFD modeling studies were performed to provide guidance for the experimental team in the selection of release sites and in the deployment of wind and concentration sensors. Also, while meteorological and concentration measurements were taken over the greater Oklahoma City urban area, our CFD calculations were focused on the near field of the release point. The proximity of the source to a large commercial building and to the neighboring buildings several of which have multistories, present a significant challenge even for CFD calculations involving grid resolutions as fine as 1 meter. A total of 10 Intensive Observations Periods (IOP's) were conducted within the 2003 field experiments. SF6 releases in the form of puffs or continuous sources were disseminated over 6 daytime and 4 nighttime episodes. Many wind and concentration sensors were used to provide wind and SF6 data over both long and short time-averaging periods. In addition to the usual near surface measurements, data depicting vertical profiles of wind and concentrations adjacent to the outside walls of several buildings were also taken. Also of interest were observations of the trajectory of balloons that were deployed close to the tracer release area. Many of the balloons released exhibit extremely quick ascents up from ground level to the top of buildings, thus implying highly convective conditions. In this paper we will present some simulations that were performed during the planning of the field experiments. The calculations were based on two possible release sites at the intersections of Sheridan and Robinson, and Broadway and Sheridan. These results provided initial information on flow and dispersion patterns, which could be used to guide optimal placement of sensors at appropriate locations. We will also discuss results of more recent simulations for several releases in which reliable data is available. These simulations will be compared with the near field data taken from the wind sensors as well as the time-averaged data from the concentration sensors. Among the other topics discussed are initial and boundary conditions used in the simulations, adaptation of building GIS data for CFD modeling and analysis of field data.
An Experimental Study of Cold Helium Dispersion in Air
Chorowski, M; Riddone, G
2002-01-01T23:59:59.000Z
The Large Hadron Collider (LHC) presently under construction at CERN, will contain about 100 tons of helium mostly located in the underground tunnel and in caverns. Potential failure modes of the accelerator, which may be followed by helium discharge to the tunnel, have been identified and the corresponding helium flows calculated. To verify the analytical calculations of helium dispersion in the tunnel, a dedicated test set-up has been built. It represents a section of the LHC tunnel at a scale 1:13 and is equipped with a controllable helium relief system enabling the simulation of different scenarios of the LHC cryogenic system failures. Corresponding patterns of cold helium dispersion in air have been observed and analysed with respect to oxygen deficiency hazard. We report on the test set-up and the measurement results, which have been scaled to real LHC conditions.
Development of a GIS Based Dust Dispersion Modeling System.
Rutz, Frederick C.; Hoopes, Bonnie L.; Crandall, Duard W.; Allwine, K Jerry
2004-08-12T23:59:59.000Z
With residential areas moving closer to military training sites, the effects upon the environment and neighboring civilians due to dust generated by training exercises has become a growing concern. Under a project supported by the Strategic Environmental Research and Development Program (SERDP) of the Department of Defense, a custom application named DUSTRAN is currently under development that integrates a system of EPA atmospheric dispersion models with the ArcGIS application environment in order to simulate the dust dispersion generated by a planned training maneuver. This integration between modeling system and GIS application allows for the use of real world geospatial data such as terrain, land-use, and domain size as input by the modeling system. Output generated by the modeling system, such as concentration and deposition plumes, can then be displayed upon accurate maps representing the training site. This paper discusses the development of this integration between modeling system and Arc GIS application.
Non-Darcian forced convection in porous media with anisotropic dispersion
Adnani, P.; Catton, I.; Abdou, M.A. [Univ. of California, Los Angeles, CA (United States)
1995-05-01T23:59:59.000Z
Convective heat transfer in a particle packed tube is modeled in this paper. Axial and radial dispersion are both included in the governing equations. Results are compared with experimental data, and with previously developed models that did not include axial dispersion. It is shown that heat transfer in the thermally developing region is affected by axial dispersion when Peclet number is smaller than 10. Graphic results are provided to show the importance of axial dispersion for various Peclet numbers. 17 refs., 5 figs.
Simulation of miscible displacement in soils and sensitivity to the dispersion coefficient
Smajstrla, Allen George
1973-01-01T23:59:59.000Z
in the porous media to the magnitude of the dispersion coefficient in the diffusion-type dispersion equation. Three simulation models were developed. One was capable of simulating unsaturated vertical infiltration of water into a homo- geneous, isotropic... porous media. The second simulated saturated dispersion of solutes during the steady state flow of water through homogeneous, isotropic porous media. The third general dispersion simulation model combined the aforementioned two and was capable...
A dispersion curve study of dredged spoil basin inlets
Male, Robert
1974-01-01T23:59:59.000Z
13 19 IV. PROCEDURES AND TECHNIOUHS Test Procenures. Interpretation of Dispersion Curves. Data Analysis, 26 26 28 37 V. EXPERIMENTAL RESULTS. VI. DISCUSSION. The Model as a Settling Tank Relationship to Dredging Practice. 58 58 70 VII... all the spoil must be confined. The additional costs to be incurred in that region over ten years vary from $2. 62 million to $12. 87 million according to the confinement scheme. In the USA, most of the dredging projects are under the con- trol...
GIS and plume dispersion modeling for population exposure assessment
Archer, Jeffrey Keith
1998-01-01T23:59:59.000Z
. CHAPTER vll I INTRODUCTION. II REVIEW OF PREVIOUS RESEARCH III JUSTIFICATION AND OBJECTIVES. 3. 1 Justification. 3. 2 Project Objectives. IV METHODOLOGY . . . 15 . 15 . . . 17 . . 19 4. 1 The Study Site. 4. 2 Pollution Plume Dispersion Data.... 4. 3 Spatial and Demographic Data. 4. 4 Data Integration. V RESULTS. . . . . 19 . . . 21 . . . 36 . . 45 VI CONCLUSIONS. . . . . 60 6. 1 Conclusions, 6. 2 Room for Improvement. REFERENCES. APPENDIX A: Charts and Data Sheets. 60 . . . 61...
Preliminary assessment of regional dispersivity of the Hanford basalts
LaVenue, Arthur Marsh
1985-01-01T23:59:59.000Z
. ACKNONLEDGEMENTS I would like to thank the members of my graduate research committee, Dr. Patrick Domenico, Dr. Earl Hoskins, and Dr. James Russell for their corvaents and discussions during this study. I am thankful to Rockwell International-Hanford Operations... level nuclear waste repository, it is essential that the dispersivities be determined in order to aid in modelling studies that will be needed to characterize the site. GENERAL PHYSICAL NATURE OF HANFORD SITE Regional Setting The United States...
Global regularity of critical Schrödinger maps: subthreshold dispersed energy
Paul Smith
2012-12-19T23:59:59.000Z
We consider the energy-critical Schroedinger map initial value problem with smooth initial data from R^2 into the sphere S^2. Given sufficiently energy-dispersed data with subthreshold energy, we prove that the system admits a unique global smooth solution. This improves earlier analogous conditional results. The key behind this improvement lies in exploiting estimates on the commutator of the Schroedinger map and harmonic map heat flows.
Hanford atmospheric dispersion data: 1960 through June 1967
Nickola, P.W.; Ramsdell, J.V.; Glantz, C.S.; Kerns, R.E.
1983-11-01T23:59:59.000Z
This volume presents dispersion and supporting meteorological data from experiments conducted over relatively flat terrain at Hanford, Washington from January 1960 through June 1967. The nature of the experiments, the sampling grids, and the tracer techniques used are described in the narrative portion of the document. Appendices contain the time-integrated concentrations for samplers within the plumes, summaries of the concentration distributions across the plumes, and wind and temperature profile data for each release period. 18 references, 7 figures, 3 tables.
Estimating dispersion from a tornado vortex and mesocyclone
Weber, A.H.; Hunter, C.H.
1996-06-01T23:59:59.000Z
Atmospheric dispersion modeling is required to ensure that a postulated breach in radionuclide storage containers at the Savannah River Site (SRS) from a tornado strike of Fujita-scale intensity F2 or higher will not result in an unacceptable dose to individuals. Fujita-scale tornado descriptions are included in Appendix A of this report. Dispersion models previously used at SRS for estimating dispersion following a tornado strike were developed by D.W. Pepper in 1975 (DP-1387, Dispersion of Small Particles) and H.R. Haynes and D.W. Taylor in 1983 (DPST-82-982, Estimating Doses from Tornado Winds). Research conducted in 1983 on the formation and evolution of tornadic thunderstorms has lead to a more complete understanding of the tornado vortex and associated persistent updraft and downdraft regions within the parent thunderstorm. To ensure that appropriate, contemporary methods are used for safety analysis, the Pepper model and the Haynes and Taylor model were evaluated with respect to current knowledge of circulations within tornadic thunderstorms. Pepper`s model is complex numerically but contains most of the desired physical parameterizations. Haynes and Taylor`s model is used with the Puff-Plume model (an emergency response model on the Weather INformation and Display System at SRS) and has provisions for radionuclide deposition and rainout. Haynes and Taylor assumed heavy rain following the tornado for a period of ten minutes, followed by a lighter rain for another ten minutes, then no rain for the period when the material is transported to 100 km downwind. However, neither model incorporates the effects of a nearby thunderstorm downdraft.
Atmospheric dispersion estimates in the vicinity of buildings
Ramsdell, J.V. Jr.; Fosmire, C.J.
1995-01-01T23:59:59.000Z
A model describing atmospheric dispersion in the vicinity of buildings was developed for the U.S. Nuclear Regulatory Commission (NRC) in the late 1980s. That model has recently undergone additional peer review. The reviewers identified four areas of concern related to the model and its application. This report describes revisions to the model in response to the reviewers concerns. Model revision involved incorporation of explicit treatment of enhanced dispersion at low wind speeds in addition to explicit treatment of enhanced dispersion at high speeds resulting from building wakes. Model parameters are evaluated from turbulence data. Experimental diffusion data from seven reactor sites are used for model evaluation. Compared with models recommended in current NRC guidance to licensees, the revised model is less biased and shows more predictive skill. The revised model is also compared with two non-Gaussian models developed to estimate maximum concentrations in building wakes. The revised model concentration predictions are nearly the same as the predictions of the non-Gaussian models. On the basis of these comparisons of the revised model concentration predictions with experimental data and the predictions of other models, the revised model is found to be an appropriate model for estimating concentrations in the vicinity of buildings.
1-D profiling using highly dispersive guided waves
Volker, Arno; Zon, Tim van [TNO, Stieltjesweg 1, P.O. box 155 2600 AD Delft (Netherlands)
2014-02-18T23:59:59.000Z
Corrosion is one of the industries major issues regarding the integrity of assets. Currently, inspections are conducted at regular intervals to ensure a sufficient integrity level of these assets. Cost reduction while maintaining a high level of reliability and safety of installations is a major challenge. There are many situations where the actual defect location is not accessible, e.g., a pipe support or a partially buried pipe. Guided wave tomography has been developed to reconstruct the wall thickness of steel pipes. In case of bottom of the line corrosion, i.e., a single corrosion pit, a simpler approach may be followed. Data is collected in a pitch-catch configuration at the 12 o'clock position using highly dispersive guided waves. After dispersion correction the data collapses to a short pulse, any residual dispersion indicates wall loss. The phase spectrum is used to invert for the wall thickness profile in the circumferential direction, assuming a Gaussian defect profile. The approach is evaluated on numerically simulated and on measured data. The method is intended for rapid, semi-quantitative screening of pipes.
HUNTING FOR YOUNG DISPERSING STAR CLUSTERS IN IC 2574
Pellerin, Anne [Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843-4242 (United States); Meyer, Martin M. [International Centre for Radio Astronomy Research, University of Western Australia, 35 Stirling Highway, CRAWLEY WA 6009 (Australia); Calzetti, Daniella [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Harris, Jason, E-mail: apellerin@mta.ca, E-mail: martin.meyer@uwa.edu.au, E-mail: calzetti@astro.umass.edu, E-mail: jharris@30doradus.org [Illumina, Inc., 25861 Industrial Blvd, Hayward, CA 94545 (United States)
2012-12-01T23:59:59.000Z
Dissolving stellar groups are very difficult to detect using traditional surface photometry techniques. We have developed a method to find and characterize non-compact stellar systems in galaxies where the young stellar population can be spatially resolved. By carrying out photometry on individual stars, we are able to separate the luminous blue stellar population from the star field background. The locations of these stars are used to identify groups by applying the HOP algorithm, which are then characterized using color-magnitude and stellar density radial profiles to estimate age, size, density, and shape. We test the method on Hubble Space Telescope Advanced Camera for Surveys archival images of IC 2574 and find 75 dispersed stellar groups. Of these, 20 highly dispersed groups are good candidates for dissolving systems. We find few compact systems with evidence of dissolution, potentially indicating that star formation in this galaxy occurs mostly in unbound clusters or groups. These systems indicate that the dispersion rate of groups and clusters in IC 2574 is at most 0.45 pc Myr{sup -1}. The location of the groups found with HOP correlate well with H I contour map features. However, they do not coincide with H I holes, suggesting that those holes were not created by star-forming regions.
A Dispersive Treatment of $K_{\\ell4}$ Decays
Colangelo, Gilberto; Stoffer, Peter
2015-01-01T23:59:59.000Z
$K_{\\ell4}$ decays offer several reasons of interest: they allow an accurate measurement of $\\pi\\pi$-scattering lengths; they provide the best source for the determination of some low-energy constants of ChPT; one form factor is directly related to the chiral anomaly, which can be measured here. We present a dispersive treatment of $K_{\\ell4}$ decays that provides a resummation of $\\pi\\pi$- and $K\\pi$-rescattering effects. The free parameters of the dispersion relation are fitted to the data of the high-statistics experiments E865 and NA48/2. The matching to ChPT at NLO and NNLO enables us to determine the LECs $L_1^r$, $L_2^r$ and $L_3^r$. With recently published data from NA48/2, the LEC $L_9^r$ can be determined as well. In contrast to a pure chiral treatment, the dispersion relation describes the observed curvature of one of the form factors, which we understand as a rescattering effect beyond NNLO.
Creation of the model and implementation of the simulation of dispersion of air pollution in urban
Bargiela, Andrzej
Creation of the model and implementation of the simulation of dispersion of air pollution in urban..............................................................................................................1 1.2. Types of models of dispersion of air pollution was creation of the mathematical model and application of the simulation of dispersion of vehicular air
Dispersion modeling of ground-level area sources of particulate
Fritz, Bradley Keith
1998-01-01T23:59:59.000Z
, as shown by Equation 3. f(z) = exp ?, + exp? Y This curve represents the distribution of pollutant in the y-z plane. At any point y, a fraction of the total area of the curve [1] is determined The width of the curve depends on o?, a dispersion... the terminal settling velocity. Equation 6 and 7 are used. C p p dp g 18' where: t-o. ss, 'I C = 1+ ? 2. 514+ 0. 8e d (Eq. 6) (Eq 7) V, = Terminal Settling Velocity [m/s] C = Cunningham's Correction Factor [1/1] p, = density; 1500 [kg/m'] ) = gas...
Extracellular Proteins Limit the Dispersal of BiogenicNanoparticles
Moreau, John W.; Weber, Peter K.; Martin, Michael C.; Gilbert,Benjamin; Hutcheon, Ian D.; Banfield, Jillian F.
2007-04-27T23:59:59.000Z
High spatial-resolution secondaryion microprobespectrometry, synchrotron radiation Fourier-transform infraredspectroscopy and polyacrylamide gel analysis demonstrate the intimateassociation of proteins with spheroidal aggregates of biogenic zincsulfide nanocrystals, an example of extracellular biomineralization.Experiments involving synthetic ZnS nanoparticles and representativeamino acids indicate a driving role for cysteine in rapid nanoparticleaggregation. These findings suggest that microbially-derivedextracellular proteins can limit dispersal of nanoparticulatemetal-bearing phases, such as the mineral products of bioremediation,that may otherwise be transported away from their source by subsurfacefluid flow.
LMFBR fuel assembly design for HCDA fuel dispersal
Lacko, Robert E. (North Huntingdon, PA); Tilbrook, Roger W. (Monroeville, PA)
1984-01-01T23:59:59.000Z
A fuel assembly for a liquid metal fast breeder reactor having an upper axial blanket region disposed in a plurality of zones within the fuel assembly. The characterization of a zone is dependent on the height of the axial blanket region with respect to the active fuel region. The net effect of having a plurality of zones is to establish a dispersal flow path for the molten materials resulting during a core meltdown accident. Upward flowing molten material can escape from the core region and/or fuel assembly without solidifying on the surface of fuel rods due to the heat sink represented by blanket region pellets.
Measurement of vehicle emissions and the associated dispersion near roadways
Hlavinka, M. W
1986-01-01T23:59:59.000Z
air po)lution inodels by collec4ing data, for use in thc verification of these models. This objectives is accomplished through the following ma)or tasks: (l) Collect, ion of a large roadway air pollution data hase on magnetic t, ape so that... correla), iona to calcula4e the dispersion parame- ters. Several authors (Rao, et sl. and I'skridge& et sl. ' ) have suggested that, induced turbulence near roadways due 4o ), he tra)fic may play a larger role in pol)utant disper- sion I, han a4...
Structure of graphene oxide dispersed with ZnO nanoparticles
Yadav, Rishikesh, E-mail: rishikesh.yadav62@gmail.com; Pandey, Devendra K., E-mail: devendrakphy@gmail.com [School of Nanotechnology, Rajiv Gandhi Proudyogiki Vishwavidalaya, Bhopal, M.P. (India); Khare, P. S., E-mail: purnimaswarup@hotmail.com [Department of Physics, Rajiv Gandhi Proudyogiki Vishwavidalaya, Bhopal M.P. (India)
2014-10-15T23:59:59.000Z
Graphene has been proposed as a promising two-dimensional nanomaterial with outstanding electronic, optical, thermal and mechanical properties for many applications. In present work a process of dispersion of graphene oxide with ZnO nanoparticles in ethanol solution with different pH values, have been studied. Samples have been characterized by XRD, SEM, PL, UV-visible spectroscopy and particles size measurement. The results analysis indicates overall improved emission spectrum. It has been observed that the average diameter of RGO (Reduced Graphene Oxide) decreases in presence of ZnO nanoparticles from 3.8?m to 0.41?m.
Air Dispersion Modeling for Building 3026C/D Demolition
Ward, Richard C [ORNL; Sjoreen, Andrea L [ORNL; Eckerman, Keith F [ORNL
2010-06-01T23:59:59.000Z
This report presents estimates of dispersion coefficients and effective dose for potential air dispersion scenarios of uncontrolled releases from Oak Ridge National Laboratory (ORNL) buildings 3026C, 3026D, and 3140 prior to or during the demolition of the 3026 Complex. The Environmental Protection Agency (EPA) AERMOD system1-6 was used to compute these estimates. AERMOD stands for AERMIC Model, where AERMIC is the American Meteorological Society-EPA Regulatory Model Improvement Committee. Five source locations (three in building 3026D and one each in building 3026C and the filter house 3140) and associated source characteristics were determined with the customer. In addition, the area of study was determined and building footprints and intake locations of air-handling systems were obtained. In addition to the air intakes, receptor sites consisting of ground level locations on four polar grids (50 m, 100 m, 200 m, and 500 m) and two intersecting lines of points (50 m separation), corresponding to sidewalks along Central Avenue and Fifth Street. Three years of meteorological data (2006 2008) were used each consisting of three datasets: 1) National Weather Service data; 2) upper air data for the Knoxville-Oak Ridge area; and 3) local weather data from Tower C (10 m, 30 m and 100 m) on the ORNL reservation. Annual average air concentration, highest 1 h average and highest 3 h average air concentrations were computed using AERMOD for the five source locations for the three years of meteorological data. The highest 1 h average air concentrations were converted to dispersion coefficients to characterize the atmospheric dispersion as the customer was interested in the most significant response and the highest 1 h average data reflects the best time-averaged values available from the AERMOD code. Results are presented in tabular and graphical form. The results for dose were obtained using radionuclide activities for each of the buildings provided by the customer.7 Radiation dose was calculated assuming complete release of the building inventory as information was lacking regarding the portion of the building inventory expected to be released. Thus the results are derived using an extremely conservative release as documented in the Preliminary Hazard Screening report.7 To more closely approximate the result of a release, one must estimate the fraction of the total inventory released and multiply the results described above by that fraction. An example of how this calculation is accomplished is provided. Should an actual uncontrolled release occur, the results of this modeling effort could only be used to establish a rough order-of-magnitude for the event.
Dispersion toughened ceramic composites and method for making same
Stinton, D.P.; Lackey, W.J.; Lauf, R.J.
1984-09-28T23:59:59.000Z
Ceramic composites exhibiting increased fracture toughness are produced by the simultaneous codeposition of silicon carbide and titanium disilicide by chemical vapor deposition. A mixture of hydrogen, methyltrichlorosilane and titanium tetrachloride is introduced into a furnace containing a substrate such as graphite or silicon carbide. The thermal decomposition of the methyltrichlorosilane provides a silicon carbide matrix phase and the decomposition of the titanium tetrachloride provides a uniformly dispersed second phase of the intermetallic titanium disilicide within the matrix phase. The fracture toughness of the ceramic composite is in the range of about 6.5 to 7.0 MPa..sqrt..m which represents a significant increase over that of silicon carbide.
Implications of various dispersants on biofilm clean up processes
Beardwood, E.S.; Therrien, J.K.
1999-07-01T23:59:59.000Z
A microbiologically fouled industrial cooling water system was investigated utilizing a portable corrosion and fouling monitor according to the NACE RP0189-951 Standard. Baseline data was established and at which time the monitor was subjected to various dispersants (3) typically used for organic and microbiological deposit removal. The results of this in-field, side stream, experiment on a dynamic system will be presented. A number of key points and factors influencing the performance of the foulant clean up will also be discussed.
Electrophoresis of colloidal dispersions in the low-salt regime
Vladimir Lobaskin; Burkhard Duenweg; Martin Medebach; Thomas Palberg; Christian Holm
2006-12-15T23:59:59.000Z
We study the electrophoretic mobility of spherical charged colloids in a low-salt suspension as a function of the colloidal concentration. Using an effective particle charge and a reduced screening parameter, we map the data for systems with different particle charges and sizes, including numerical simulation data with full electrostatics and hydrodynamics and experimental data for latex dispersions, on a single master curve. We observe two different volume fraction-dependent regimes for the electrophoretic mobility that can be explained in terms of the static properties of the ionic double layer.
Computer simulation of the dispersion of carbon monoxide from roadways
Maldonado, Cesar
1976-01-01T23:59:59.000Z
and stability 3) The wind speed is constant with height 4) Dispersion is independent of site topography The equations used in the model are, for crosswinds, 12. 5~ & O & 90', 4. 24 1 z+h 2 1 1 z-h 2& exp p ? ( ?) g+ exp ? ( ? ) j L Ro sino 2 CJ 2 0 z (34... to include az for vertical distances as small as 4 meters Same as above Pasquill-Gitford and empirical calibration o an initial az to 1. 5 meters Pasquill-Gifford None short (3 ? 10 mm) releases smooth terrain Same as above Same as above smooth...
Dispersion toughened ceramic composites and method for making same
Stinton, David P. (Knoxville, TN); Lackey, Walter J. (Oak Ridge, TN); Lauf, Robert J. (Oak Ridge, TN)
1986-01-01T23:59:59.000Z
Ceramic composites exhibiting increased fracture toughness are produced by the simultaneous codeposition of silicon carbide and titanium disilicide by chemical vapor deposition. A mixture of hydrogen, methyltrichlorosilane and titanium tetrachloride is introduced into a furnace containing a substrate such as graphite or silicon carbide. The thermal decomposition of the methyltrichlorosilane provides a silicon carbide matrix phase and the decomposition of the titanium tetrachloride provides a uniformly dispersed second phase of the intermetallic titanium disilicide within the matrix phase. The fracture toughness of the ceramic composite is in the range of about 6.5 to 7.0 MPa.sqroot.m which represents a significant increase over that of silicon carbide.
RADIONUCLIDE DISPERSION RATES BY AEOLIAN, FLUVIAL, AND POROUS MEDIA TRANSPORT
J. Walton; P. Goodell; C. Brashears; D. French; A. Kelts
2005-07-11T23:59:59.000Z
Radionuclide transport was measured from high grade uranium ore boulders near the Nopal I Site, Chihuahua, Mexico. High grade uranium ore boulders were left behind after removal of a uranium ore stockpile at the Prior High Grade Stockpile (PHGS). During the 25 years when the boulder was present, radionuclides were released and transported by sheetflow during precipitation events, wind blown resuspension, and infiltration into the unsaturated zone. In this study, one of the boulders was removed, followed by grid sampling of the surrounding area. Measured gamma radiation levels in three dimensions were used to derive separate dispersion rates by the three transport mechanisms.
Achromatic phase matching at third orders of dispersion
Richman, Bruce
2003-10-21T23:59:59.000Z
Achromatic phase-matching (APM) is used for efficiently multiplying the frequency of broad bandwidth light by using a nonlinear optical medium comprising a second-harmonic generation (SHG) crystal and stationary optical elements whose configuration, properties, and arrangement have been optimized to match the angular dispersion characteristics of the SHG crystal to at least the third order. These elements include prisms and diffraction gratings for directing an input light beam onto the SHG crystal such that each ray wavelength is aligned to match the phase-matching angle for the crystal at each wavelength of light to at least the third order and such that every ray wavelength overlap within the crystal.
Electromagnetic energy dispersion in a 5D universe
Hartnett, John G. [School of Physics, University of Western Australia, 35 Stirling Hwy, Crawley 6009 WA Australia (Australia)
2010-06-15T23:59:59.000Z
Electromagnetism is analyzed in a 5D expanding universe. Compared to the usual 4D description of electrodynamics it can be viewed as adding effective charge and current densities to the universe that are static in time. These lead to effective polarization and magnetization of the vacuum, which is most significant at high redshift. Electromagnetic waves propagate but group and phase velocities are dispersive. This introduces a new energy scale to the cosmos. And as a result electromagnetic waves propagate with superluminal speeds but no energy is transmitted faster than the canonical speed of light c.
Dispersive approach to hadronic light-by-light scattering
Gilberto Colangelo; Martin Hoferichter; Massimiliano Procura; Peter Stoffer
2014-08-22T23:59:59.000Z
Based on dispersion theory, we present a formalism for a model-independent evaluation of the hadronic light-by-light contribution to the anomalous magnetic moment of the muon. In particular, we comment on the definition of the pion pole in this framework and provide a master formula that relates the effect from pi pi intermediate states to the partial waves for the process gamma^* gamma^* --> pi pi. All contributions are expressed in terms of on-shell form factors and scattering amplitudes, and as such amenable to an experimental determination.
Shock-Dispersed-Fuel Charges: Combustion in Chambers and Tunnels
Neuwald, P; Reichenbach, H; Kuhl, A L
2003-04-22T23:59:59.000Z
In previous studies we have investigated after-burning effects of a fuel-rich explosive (TNT). In that case the detonation only releases about 30% of the available energy, but generates a hot cloud of fuel that can burn in the ambient air, thus evoking an additional energy release that is distributed in space and time. The current series of small-scale experiments can be looked upon as a natural generalization of this mechanism: a booster charge disperses a (non-explosive) fuel, provides mixing with air and, by means of the hot detonation products, the energy to ignite the fuel. The current version of our miniature Shock-Dispersed-Fuel (SDF) charges consists of a spherical booster charge of 0.5 g PETN, embedded in a paper cylinder of approximately 2.2 cm, which is filled with powdered fuel compositions. The main compositions studied up to now contain aluminum flakes, hydrocarbon powders like polyethylene or hexosen (sucrose) and/or carbon particles. These charges were studied in four different chambers: two cylindrical vessels of 6.6-1 and 40.5-1 volume with a height-to-diameter ratio of approximately 1, a rectangular chamber of 41 (10.5 x 10.5 x 38.6 cm) and a 299.6 cm long tunnel model with a cross section of 8 x 8 cm (volume 19.21) closed at both ends.
A multi-crystal wavelength dispersive x-ray spectrometer
Alonso-Mori, Roberto; Montanez, Paul; Delor, James; Bergmann, Uwe [LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Kern, Jan [LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720-8099 (United States); Sokaras, Dimosthenis; Weng, Tsu-Chien; Nordlund, Dennis [SSRL, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Tran, Rosalie; Yachandra, Vittal K.; Yano, Junko [Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720-8099 (United States)
2012-07-15T23:59:59.000Z
A multi-crystal wavelength dispersive hard x-ray spectrometer with high-energy resolution and large solid angle collection is described. The instrument is specifically designed for time-resolved applications of x-ray emission spectroscopy (XES) and x-ray Raman scattering (XRS) at X-ray Free Electron Lasers (XFEL) and synchrotron radiation facilities. It also simplifies resonant inelastic x-ray scattering (RIXS) studies of the whole 2d RIXS plane. The spectrometer is based on the Von Hamos geometry. This dispersive setup enables an XES or XRS spectrum to be measured in a single-shot mode, overcoming the scanning needs of the Rowland circle spectrometers. In conjunction with the XFEL temporal profile and high-flux, it is a powerful tool for studying the dynamics of time-dependent systems. Photo-induced processes and fast catalytic reaction kinetics, ranging from femtoseconds to milliseconds, will be resolvable in a wide array of systems circumventing radiation damage.
Velocity dispersion and upscaling in a laboratory-simulated VSP
Rio, P.; Mukerji, T.; Mavko, G. [Stanford Univ., CA (United States)] [Stanford Univ., CA (United States); Marion, D. [Elf Aquitaine, Pau (France)] [Elf Aquitaine, Pau (France)
1996-03-01T23:59:59.000Z
A laboratory and numerical study was conducted to investigate the impact of scale-dependent seismic wave propagation in randomly layered media, as applied to sonic logs, surface seismic, and vertical seismic profiles (VSPs). Analysis of the laboratory results (1) confirmed the wavelength dependence of velocities inferred from traveltimes, (2) indicated that scale effects can introduce traveltime errors when upscaling from logs to surface seismic and VSPs, and (3) illustrated that erroneous VSP interval velocities can result when layer thicknesses are smaller than about one-tenth of the wavelength. A simple approximate recipe is presented for estimating these traveltimes by successively filtering the medium using a running Backus average and ray theory. The scale-dependent dispersion was also predicted well using a more rigorous invariant imbedding formulation. The predicted traveltimes, using the approximate recipe, compare well with the times observed in the laboratory stack of steel and plastic layers and in numerical studies of stratified media. The dispersion curves predicted by the approximate method also show the overall behavior computed with the more rigorous invariant imbedding formulation.
Low-pressure debris dispersal from scaled reactor cavities
Nichols, R.T.; Tarbell, W.W.
1988-01-01T23:59:59.000Z
During a severe nuclear reactor accident, degradation of the core may result in debris accumulating in the lower head. Upon failure of the head, the melt may be ejected under pressure through the cavity and into the containment building. Under low system pressure conditions, understanding the mechanisms of debris dispersal is instrumental in assessing the response of the containment to pressurized melt ejection. Current analytical approaches rely on empirical correlations for debris entrainment criteria and very simple gas flow patterns in the cavity. The work reported here is directed toward performing scaled experiments that will develop a data base for refined scaling analyses. Subsequently, extrapolations from the analyses to reactor scale may be performed to provide insight for accident predictions. Mechanistic models for gas flow through the cavity and entrainment of the debris are also being developed from the results presented here. The objective of the test matrix is to vary key parameters to assess the effect on the physical processes of dispersal of the melt from the reactor cavity at low system pressures.
Dispersion modeling and analysis for multilayered open coaxial waveguides
Sven Nordebo; Gokhan Cinar; Stefan Gustafsson; Borje Nilsson
2014-02-20T23:59:59.000Z
This paper presents a detailed modeling and analysis regarding the dispersion characteristics of multilayered open coaxial waveguides. The study is motivated by the need of improved modeling and an increased physical understanding about the wave propagation phenomena on very long power cables which has a potential industrial application with fault localization and monitoring. The electromagnetic model is based on a layer recursive computation of axial-symmetric fields in connection with a magnetic frill generator excitation that can be calibrated to the current measured at the input of the cable. The layer recursive formulation enables a stable and efficient numerical computation of the related dispersion functions as well as a detailed analysis regarding the analytic and asymptotic properties of the associated determinants. Modal contributions as well as the contribution from the associated branch-cut (non-discrete radiating modes) are defined and analyzed. Measurements and modeling of pulse propagation on an 82 km long HVDC power cable are presented as a concrete example. In this example, it is concluded that the contribution from the second TM mode as well as from the branch-cut is negligible for all practical purposes. However, it is also shown that for extremely long power cables the contribution from the branch-cut can in fact dominate over the quasi-TEM mode for some frequency intervals. The main contribution of this paper is to provide the necessary analysis tools for a quantitative study of these phenomena.
Paris-Sud XI, Université de
) exposed to dispersed crude oil2 3 Thomas Milinkovitch1* , Awa Ndiaye2 , Wilfried Sanchez2 , Stéphane Le ; CD : Chemically Dispersed oil ; D : Dispersant solution ; MD : Mechanically Dispersed oil; WSF application is an oil spill response technique. To evaluate the environmental31 cost of this operation
Boyer, Edmond
to chemically dispersed oil2 3 Luna-Acosta, A.a,* , Kanan, R.b , Le Floch, S.b , Huet, V.a , Pineau P;Abstract: The aim of this study was to evaluate the effects of chemically dispersed oil on an20 of the chemical dispersant. After 2 days of exposure to chemically dispersed28 oil, alkylated naphthalenes
The relation between seismic P- and S-wave velocity dispersion in saturated rocks
Mavko, G. [Stanford Univ., CA (United States). Dept. of Geophysics] [Stanford Univ., CA (United States). Dept. of Geophysics; Jizba, D. [CSTJF, Pau (France)] [CSTJF, Pau (France)
1994-01-01T23:59:59.000Z
Seismic velocity dispersion in fluid-saturated rocks appears to be dominated by two mechanisms: the large scale mechanism modeled by Biot, and the local flow or squirt mechanism. The two mechanisms can be distinguished by the ratio of P- to S-wave dispersions, or more conveniently, by the ratio of dynamic bulk to shear compliance dispersions derived from the wave velocities. The authors` formulation suggests that when local flow dominates, the dispersion of the shear compliance will be approximately 4/15 the dispersion of the compressibility. When the Biot mechanism dominates, the constant of proportionality is much smaller. Their examination of ultrasonic velocities from 40 sandstones and granites shows that most, but not all, of the samples were dominated by local flow dispersion, particularly at effective pressures below 40 MPa.
Flow Intermittency, Dispersion, and Correlated Continuous Time Random Walks in Porous Media
de Anna, Pietro; Le Borgne, Tanguy; Dentz, Marco; Tartakovsky, Alexandre M.; Bolster, Diogo; Davy, Philippe
2013-05-01T23:59:59.000Z
We study the intermittency of fluid velocities in porous media and its relation to anomalous dispersion. Lagrangian velocities measured at equidistant points along streamlines are shown to form a spatial Markov process. As a consequence of this remarkable property, the dispersion of fluid particles can be described by a continuous time random walk with correlated temporal increments. This new dynamical picture of intermittency provides a direct link between the microscale flow, its intermittent properties, and non-Fickian dispersion.
animal-mediated seed dispersal: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Stouffer, School of Biological Sciences, Univ. of Canterbury, Univ. of Extremadura, Av. Virgen del Puerto 2, ES-10600 Plasencia, Spain. Seed dispersal by animals Stouffer, Daniel...
Distribution and Dispersal of the South Pacifc Tree, Fagraea Berteriana (Loganiaceae)
Hanna, Zachary R.
2006-01-01T23:59:59.000Z
addressing the ridge top distribution phenomenon. ADISTRIBUTION AND DISPERSAL OF THE SOUTH PACIFC TREE, FAGRAEAits inter? island distribution in the South Pacific. I
Dispersal of planets hosted in binaries, transitional members of multiple star systems
F. Marzari; M. Barbieri
2007-07-04T23:59:59.000Z
This paper explains why planets in binary star systems might have a lower frequency. A transient triple state of the binary causes the dispersal of planets.
A model for P-wave attenuation and dispersion in a porous medium ...
lll
2005-09-05T23:59:59.000Z
Theoretical models of attenuation and dispersion due to wave-induced fluid flow ...... anisotropic layered fluid- and gas-saturated sediments, Geophysics, 62,.
Modulus dispersion and attenuation in tuff and granite
Haupt, R.W.; Martin, R.J. III; Tang, X.; Dupree, W.J. [New England Research, Inc., White River Junction, VT (United States); Price, R.H. [Sandia National Labs., Albuquerque, NM (United States)
1991-12-23T23:59:59.000Z
The effects of loading frequency, strain amplitude, and saturation on elastic moduli and attenuation have been measured in samples of the Topopah Spring Member welded tuff. Four different laboratory techniques have been used to determine Young`s modulus and extensional wave attenuation at frequencies ranging from 10{sup {minus}2} to 10{sup 6} Hz. The results are compared with data acquired for Sierra White granite under the same conditions. The modulus and attenuation in room dry samples remain relatively constant over frequency. Frequency dependent attenuation and modulus dispersion are observed in the saturated samples and are attributed to fluid flow and sample size. The properties of tuff were independent of strain amplitude in room dry and saturated conditions.
Chromatic and Dispersive Effects in Nonlinear Integrable Optics
Webb, Stephen D; Valishev, Alexander; Nagaitsev, Sergei N; Danilov, Viatcheslav V
2015-01-01T23:59:59.000Z
Proton accumulator rings and other circular hadron accelerators are susceptible to intensity-driven parametric instabilities because the zero-current charged particle dynamics are characterized by a single tune. Landau damping can suppress these instabilities, which requires energy spread in the beam or introducing nonlinear magnets such as octupoles. However, this approach reduces dynamic aperture. Nonlinear integrable optics can suppress parametric instabilities independent of energy spread in the distribution, while preserving the dynamic aperture. This novel approach promises to reduce particle losses and enable order-of-magnitude increases in beam intensity. In this paper we present results, obtained using the Lie operator formalism, on how chromaticity and dispersion affect particle orbits in integrable optics. We conclude that chromaticity in general breaks the integrability, unless the vertical and horizontal chromaticities are equal. Because of this, the chromaticity correcting magnets can be weaker ...
The Photon Dispersion as an Indicator for New Physics ?
Wolfgang Bietenholz
2010-09-02T23:59:59.000Z
We first comment on the search for a deviation from the linear photon dispersion relation, in particular based on cosmic photons from Gamma Ray Bursts. Then we consider the non-commutative space as a theoretical concept that could lead to such a deviation, which would be a manifestation of Lorentz Invariance Violation. In particular we review a numerical study of pure U(1) gauge theory in a 4d non-commutative space. Starting from a finite lattice, we explore the phase diagram and the extrapolation to the continuum and infinite volume. These simultaneous limits - taken at fixed non-commutativity - lead to a phase of broken Poincare symmetry, where the photon appears to be IR stable, despite a negative IR divergence to one loop.
Method for dispersing catalyst onto particulate material and product thereof
Utz, Bruce R. (Pittsburgh, PA); Cugini, Anthony V. (Pittsburgh, PA)
1992-01-01T23:59:59.000Z
A method for dispersing finely divided catalyst precursors onto the surface of coal or other particulate material includes the steps of forming a wet paste mixture of the particulate material and a liquid solution containing a dissolved transition metal salt, for instance a solution of ferric nitrate. The wet paste mixture is in a state of incipient wetness with all of this solution adsorbed onto the surfaces of the particulate material without the presence of free moisture. On adding a precipitating agent such as ammonia, a catalyst precursor such as hydrated iron oxide is deposited on the surfaces of the coal. The catalyst is activated by converting it to the sulfide form for the hydrogenation or direct liquefaction of the coal.
Excitation Theory for Space-Dispersive Active Media Waveguides
Barybin, A A
1999-01-01T23:59:59.000Z
A unified electrodynamic approach to the guided-wave excitation theory is generalized to the waveguiding structures containing a hypothetical space-dispersive medium with drifting charge carriers possessing simultaneously elastic, piezoelectric and magnetic properties. Substantial features of our electrodynamic approach are: (i) the allowance for medium losses and (ii) the separation of potential fields peculiar to the slow quasi-static waves. It is shown that the orthogonal complementary fields appearing inside the external source region are just associated with a contribution of the potential fields inherent in exciting sources. Taking account of medium losses converts the usual orthogonality relation into a novel form called the quasi-orthogonality relation. It is found that the separation of potential fields reveals the fine structure of interaction between the exciting sources and mode eigenfields: in addition to the exciting currents interacting with the curl fields, the exciting charges and the double ...
Dispersive Qubit Measurement by Interferometry with Parametric Amplifiers
Sh. Barzanjeh; D. P. DiVincenzo; B. M. Terhal
2014-10-02T23:59:59.000Z
We perform a detailed analysis of how an amplified interferometer can be used to enhance the quality of a dispersive qubit measurement, such as one performed on a superconducting transmon qubit, using homodyne detection on an amplified microwave signal. Our modeling makes a realistic assessment of what is possible in current circuit-QED experiments; in particular, we take into account the frequency-dependence of the qubit-induced phase shift for short microwaves pulses. We compare the possible signal-to-noise ratios obtainable with (single-mode) SU(1,1) interferometers with the current coherent measurement and find a considerable reduction in measurement error probability in an experimentally-accessible range of parameters.
Development of oxide dispersion strengthened ferritic steels for fusion
Mukhopadhyay, D.K. [Vista Metals, Inc., McKeesport, PA (United States); Froes, F.H. [Univ. of Idaho, ID (United States); Gelles, D.S. [Pacific Northwest National Lab., Richland, WA (United States)
1998-03-01T23:59:59.000Z
An oxide dispersion strengthened (ODS) ferritic steel with high temperature strength has been developed in line with low activation criteria for application in fusion power systems. The composition Fe-13.5Cr-2W-0.5Ti-0.25Y{sub 2}O{sup 3} was chosen to provide a minimum chromium content to insure fully delta-ferrite stability. High temperature strength has been demonstrated by measuring creep response of the ODS alloy in uniaxial tension at 650 and 900 C in an inert atmosphere chamber. Results of tests at 900 C demonstrate that this alloy has creep properties similar to other alloys of similar design and can be considered for use in high temperature fusion power system designs. The alloy selection process, materials production, microstructural evaluation and creep testing are described.
Submesoscale dispersion in the vicinity of the Deepwater Horizon spill
Poje, Andrew C; Lipphardt,, Bruce; Haus, Brian K; Ryan, Edward H; Haza, Angelique C; Reniers, A J H M; Olascoaga, Josefina; Novelli, Guillaume; Beron-Vera, Francisco J; Chen, Shuyi; Mariano, Arthur J; Jacobs, Gregg; Hogan, Pat; Coelho, Emanuel; Kirwan,, A D; Huntley, Helga; Griffa, Annalisa
2014-01-01T23:59:59.000Z
Reliable forecasts for the dispersion of oceanic contamination are important for coastal ecosystems, society and the economy as evidenced by the Deepwater Horizon oil spill in the Gulf of Mexico in 2010 and the Fukushima nuclear plant incident in the Pacific Ocean in 2011. Accurate prediction of pollutant pathways and concentrations at the ocean surface requires understanding ocean dynamics over a broad range of spatial scales. Fundamental questions concerning the structure of the velocity field at the submesoscales (100 meters to tens of kilometers, hours to days) remain unresolved due to a lack of synoptic measurements at these scales. \\textcolor{black} {Using high-frequency position data provided by the near-simultaneous release of hundreds of accurately tracked surface drifters, we study the structure of submesoscale surface velocity fluctuations in the Northern Gulf Mexico. Observed two-point statistics confirm the validity of classic turbulence scaling laws at 200m$-$50km scales and clearly indicate tha...
Urban Dispersion Program Overview and MID05 Field Study Summary
Allwine, K Jerry; Flaherty, Julia E.
2007-07-31T23:59:59.000Z
The Urban Dispersion Program (UDP) was a 4-year project (2004–2007) funded by the U.S. Department of Homeland Security with additional support from the Defense Threat Reduction Agency. The U.S. Environmental Protection Agency (EPA) also contributed to UDP through funding a human-exposure component of the New York City (NYC) field studies in addition to supporting an EPA scientist in conducting modeling studies of NYC. The primary goal of UDP was to improve the scientific understanding of the flow and diffusion of airborne contaminants through and around the deep street canyons of NYC. The overall UDP project manager and lead scientist was Dr. Jerry Allwine of Pacific Northwest National Laboratory. UDP had several accomplishments that included conducting two tracer and meteorological field studies in Midtown Manhattan.
Methods and apparatus for controlling dispersions of nanoparticles
Lavrentovich, Oleg D; Golovin, Andrii B
2014-10-21T23:59:59.000Z
Electrically reconfigurable metamaterial with spatially varied refractive index is proposed for applications such as optical devices and lenses. The apparatus and method comprises a metamaterial in which the refractive indices are modified in space and time by applying one or more electric fields. The metamaterials are electrically controllable and reconfigurable, and consist of metal (gold, silver, etc.) particles of different shapes, such as rods, with dimension much smaller than the wavelength of light, dispersed in a dielectric medium. The metamaterial is controlled by applying a non-uniform electric field that causes two effects: (1) It aligns the metallic anisometric particles with respect to the direction of the applied electric field and (2) It redistributes particles in space, making their local concentration position dependent.
Combustion of Shock-Dispersed Fuels in a Chamber
Neuwald, P; Reichenbach, H; Kuhl, A L
2003-04-23T23:59:59.000Z
In previous studies we have investigated after-burning effects of a fuel-rich explosive (TNT). In that case the detonation only releases about 30 % of the available energy, but generates a hot cloud of fuel that can burn in the ambient air, thus evoking an additional energy release that is distributed in space and time. The current series of small-scale experiments can be looked upon as a natural generalization of this mechanism: a booster charge disperses a (non-explosive) fuel, provides mixing with air and - by means of the hot detonation products - energy to ignite the fuel. The current version of our miniature Shock-Dispersed-Fuel (SDF) charges consists of a spherical booster charge of 0.5 g PETN, embedded in a paper cylinder of approximately 2.2 cm3, which is filled with powdered fuel compositions. The main compositions studied up to now contain aluminum powder, hydrocarbon powders like polyethylene or sucrose and/or carbon particles. These charges were studied in three different chambers of 4-1, 6.6-1 and 40.5-1 volume. In general, the booster charge was sufficient to initiate burning of the fuel. This modifies the pressure signatures measured with a number of wall gages and increases the quasi-static overpressure level obtained in the chambers. On the one hand the time-scale and the yield of the pressure rise depend on the fuel and its characteristics. On the other hand they also depend on the flow dynamics in the chamber, which is dominated by shock reverberations, and thus on the chamber geometry and volume. The paper gives a survey of the experimental results and discusses the possible influences of some basic parameters.
Avalanche-like fluidization of an attractive dispersion
Aika Kurokawa; Valérie Vidal; Kei Kurita; Thibaut Divoux; Sébastien Manneville
2015-05-22T23:59:59.000Z
We report on the transient dynamics of an attractive silica dispersion that displays strong physical aging. Extensive rheology coupled to ultrasonic velocimetry allows us to characterize the global stress response together with the local dynamics of the gel during shear startup experiments. In practice, after being rejuvenated by a preshear, the dispersion is left to age during a time $t_w$ before being submitted to a constant shear rate $\\dot \\gamma$. We investigate in detail the effects of both $t_w$ and $\\dot \\gamma$ on the fluidization dynamics and build a complete phase diagram of the gel behavior. At large enough shear rates, the gel is fully fluidized and flows homogeneously independently of its age. Under lower shear rates, the strong interplay between aging and shear rejuvenation leads, together with wall slip, to a more complex phenomenology. The gel may either display transient shear banding towards complete fluidization, or steady-state shear banding. In the former case, we unravel that the progressive fluidization occurs by successive steps that appear as peaks on the global stress relaxation signal. Flow imaging reveals that the shear band grows up to complete fluidization of the material by sudden avalanche-like events that are correlated to large peaks in the slip velocity at the moving wall. In the case of steady-state shear banding, we recover the classical scenario involving a critical shear rate $ \\dot \\gamma_c$ below which no homogeneous steady flow is possible. We show here that $\\dot \\gamma_c$ displays a nonlinear behavior with $t_w$. Our work paves the way for a thorough description of transient flows of weak attractive gels, and highlights the subtle interplay between shear, wall slip and aging that constitutes a major challenge in terms of modeling that has yet not been met.
Not Available
1991-09-01T23:59:59.000Z
The design of a CGMCFC electric generation plant that will provide a cost of eletricity (COE) which is lower than that of current electric generation technologies and which is competitive with other long-range electric generating systems is presented. This effort is based upon the Internal Manifold Heat Exchanger (IMHEX) technology as developed by the Institute of Gas Technology (IGT). The project was executed by selecting economic and performance objectives for alternative plant arrangements while considering process constraints identified during IMHEX fuel cell development activities at ICT. The four major subsystems of a coal-based MCFC power plant are coal gasification, gas purification, fuel cell power generation and the bottoming cycle. The design and method of operation of each subsystem can be varied, and, depending upon design choices, can have major impact on both the design of other subsystems and the resulting cost of electricity. The challenge of this project was to select, from a range of design parameters, those operating conditions that result in a preferred plant design. Computer modelling was thus used to perform sensitivity analyses of as many system variables as program resources and schedules would permit. In any systems analysis, it is imperative that the evaluation methodology be verifiable and comparable. The TAG Class I develops comparable (if imprecise) data on performance and costs for the alternative cases being studied. It identifies, from a range of options, those which merit more exacting scrutiny to be undertaken at the second level, TAG class II analysis.
AHF: Array-Based Half-Facet Data Structure for Mixed-Dimensional and Non-Manifold Meshes
Dyedov, Volodymyr; Ray, Navamita; Einstein, Daniel R.; Jiao, Xiangmin; Tautges, T.
2014-08-31T23:59:59.000Z
We present an Array-based Half-Facet mesh data structure, or AHF, for efficient mesh query and modification operations. The AHF extends the compact array-based half-edge and half-face data structures (T.J. Alumbaugh and X. Jiao, Compact array-based mesh data structures, IMR, 2005) to support mixed-dimensional and non-manifold meshes. The design goals of our data structure include generality to support such meshes, efficiency of neighborhood queries and mesh modification, compactness of memory footprint, and facilitation of interoperability of mesh-based application codes. To accomplish these goals, our data structure uses sibling half-facets as a core abstraction, coupled with other explicit and implicit representations of entities. A unique feature of our data structure is a comprehensive implementation in MATLAB, which allows rapid prototyping, debugging, testing, and deployment of meshing algorithms and other mesh-based numerical methods. We have also developed C++ implementation built on top of MOAB (T.J. Tautges, R. Meyers, and K. Merkley, MOAB: A Mesh-Oriented Database, Sandia National Laboratories, 2004). We present some comparisons of the memory requirements and computational costs, and also demonstrate its effectiveness with a few sample applications.
Telescopic Time-Scale Bridging for Modeling Dispersion in Rapidly Oscillating Flows
Zakhor, Avideh
Telescopic Time-Scale Bridging for Modeling Dispersion in Rapidly Oscillating Flows Ram K between the oscillation and dispersion time scales. Here, we present a methodology based on an implicit introduced errors. The error was found to decrease with mesh refinement, but a small inherent error
Modeling of the multiscale dispersion of nanoparticles in a hematite coating , F. Willot1
Boyer, Edmond
Modeling of the multiscale dispersion of nanoparticles in a hematite coating E. Couka1 , F. Willot1 conclude in Sec. (6). 2. Hematite nanocubes coating 2.1. Dispersion of nanoparticles In this work, we-Auguste Desbruères, 91003 Evry, France. Images of a hematite-based epoxy coating are obtained by scanning electron
Dispersion and Characterization of Nickel Nanostrands in Thermoset and Thermoplastic Polymers
Whalen, Casey Allen
2012-02-14T23:59:59.000Z
research done on dispersing powdered NiNS in various polymer matrices. This thesis covers the research in dispersing NiNS in three separate polymer systems, and related composite processing and characterization. An aromatic polyimide (CP2) is first used...
Price Dispersion in the Housing Market: The Role of Bargaining and Search Costs
Boyer, Edmond
Price Dispersion in the Housing Market: The Role of Bargaining and Search Costs Gaetano Lisi bargaining powers and search costs the selling price will be different. Recently, from a theoretical point a basic fact of housing markets: price dispersion. The variance in house prices is basically due to both
Participatory Sensing in Commerce: Using Mobile Camera Phones to Track Market Price Dispersion
Bulusu, Nirupama
their choices. Nevertheless, a major cause is the consumer search cost incurred in collecting pricingParticipatory Sensing in Commerce: Using Mobile Camera Phones to Track Market Price Dispersion In economics, price dispersion refers to the price difference of a homogeneous good across different vendors
Menzie, D.E.
1995-05-01T23:59:59.000Z
The main objective of this research project is to investigate dispersion as a method of quantifying geological characterization and defining reservoir heterogeneity in order to enhance crude oil recovery. The dispersion of flow of a reservoir rock (dispersion coefficient and dispersivity) was identified as one of the physical properties of a reservoir rock by measuring the mixing of two miscible fluids, one displacing the other in a porous medium. A rock was 100% saturated with a resident fluid and displaced by a miscible fluid of equal viscosity and equal density. Some specific experiments were performed with unequal densities. Produced fluid was analyzed by refractometer, nuclear reaction, electrical conductivity and X-ray scan. Several physical and flow characteristics were measured on the sand rock sample in order to establish correlations with the measured dispersion property. Absolute permeability, effective porosity, relative permeability, capillary pressure, the heterogeneity factor and electrical conductivity were used to better understand the flow system. Linear, transverse, 2-D and 3-D dispersions were measured and used to characterize the rock heterogeneity of the flow system. A new system of measuring dispersion was developed using a gas displacing gas system in a porous medium. An attempt was also made to determine the dispersion property of an actual reservoir from present day well log data on a producing well. 275 refs., 102 figs., 17 tabs.
Nolte, David D.
Adaptive all-order dispersion compensation of ultrafast laser pulses using dynamic spectral-1396 Received 14 July 1999; accepted for publication 24 September 1999 The time-varying dispersion of ultrafast laser pulses can be self-adaptively stabilized using real-time dynamic spectral holography
Title of dissertation: Dispersion of ion gyrocenters in models of anisotropic plasma turbulence
Anlage, Steven
ABSTRACT Title of dissertation: Dispersion of ion gyrocenters in models of anisotropic plasma Department of Physics Turbulent dispersion of ion gyrocenters in a magnetized plasma is studied gradient, the focus is on transport parallel to the shear flow. The prescribed flow produces strongly
Cyclogenesis Simulation of Typhoon Prapiroon (2000) Associated with Rossby Wave Energy Dispersion*
Li, Tim
2000-01-01T23:59:59.000Z
Cyclogenesis Simulation of Typhoon Prapiroon (2000) Associated with Rossby Wave Energy Dispersion (2000), in the western North Pacific, is simulated to understand the role of Rossby wave energy process is through the conventional barotropic Rossby wave energy dispersion, which enhances the low
Coupling traffic models on networks and urban dispersion models for simulating sustainable
Ceragioli, Francesca
models for modeling and testing different traffic scenarios, in order to define the impact on air quality it with the urban dispersion model Sirane. Keywords: urban air quality, macroscopic traffic models, road networks, pollutant dispersion models, traffic emissions control. AMS subject classification: 35L65, 35L67, 60K30, 90B
Gain dispersion in Visible Light Photon Counters as a function of counting rate
Bross, A.; /Fermilab; Buscher, V.; /Freiburg U.; Estrada, J.; /Fermilab; Ginther, G.; /Rochester U.; Molina, J.; /Rio de Janeiro State U.
2005-03-01T23:59:59.000Z
We present measurements of light signals using Visible Light Photon Counters (VLPC), that indicate an increase in gain dispersion as the counting rate increases. We show that this dispersion can be understood on the basis of a recent observation of localized field reduction in VLPCs at high input rates.
Seed dispersal by wind: towards a conceptual framework of seed abscission and its contribution to
Katul, Gabriel
above some threshold wind speed and (ii) depends on the drag force generated by the wind. 2. We revisitSeed dispersal by wind: towards a conceptual framework of seed abscission and its contribution determines many aspects of seed dispersal by wind. While there is yet no complete mechanistic framework
Population Ecology at the Range Edge Survival and Dispersal of a High-Density Lepidopteran
Population Ecology at the Range Edge Survival and Dispersal of a High-Density Lepidopteran Population Cecilia Ronnås Faculty of Natural Resources and Agricultural Sciences Department of Ecology Service/Repro, Uppsala 2011 #12;Population Ecology at the Range Edge. Survival and Dispersal of a High
INVESTIGATION OF THE THERMOCHROMIC PROPERTIES OF POLYTHIOPHENES DISPERSED IN HOST POLYMERS
Euler, William B.
INVESTIGATION OF THE THERMOCHROMIC PROPERTIES OF POLYTHIOPHENES DISPERSED IN HOST POLYMERS Brett L films or in solution. However, the utilization of conjugated polymers in many electronic applications requires them to be dispersed in a host polymer matrix.2 There have been few investigations
Different generation regimes of mode-locked all-positive-dispersion all-fiber Yb laser
Kobtsev, Sergei M.
to achieve stable mode-locking and ultra-short pulse generation in an all-positive dispersion cavityDifferent generation regimes of mode-locked all-positive-dispersion all-fiber Yb laser Sergey Kobtseva , Sergey Kukarina , Sergey Smirnova , Sergey Turitsynb , Anton Latkina a Laser system laboratory
POPULATION ECOLOGY Seasonal and Spatial Dynamics of Alate Aphid Dispersal in Snap Bean
Nault, Brian
POPULATION ECOLOGY Seasonal and Spatial Dynamics of Alate Aphid Dispersal in Snap Bean Fields for viruses that may be acquired by aphids and transmitted to snap bean, Phaseolus vulgaris L. Snap bean Þelds and temporal and spatial dispersal patterns of commonly encountered aphids in commercial snap bean Þelds
Harmonic phase-dispersion microscope with a MachZehnder interferometer
Fang-Yen, Christopher
Harmonic phase-dispersion microscope with a MachÂZehnder interferometer Andrew Ahn, Changhuei Yang S. Feld Harmonic phase-dispersion microscopy (PDM) is a new imaging technique in which contrast is provided by differences in refractive index at two harmonically related wavelengths. We report a new
Washburn, Libe
2004-01-01T23:59:59.000Z
Continental Shelf Research 24 (2004) 20292043 A conceptual model for river water and sediment and Beardsley, 1995; Geyer et al., 1996), while its sediment is dispersed primarily by bottom bound- ary layer dispersal in the Santa Barbara Channel, California Jonathan A. Warricka,Ã, Leal A.K. Mertesb , Libe
Fractional advection-dispersion equations for1 modeling transport at the Earth surface2
Bäumer, Boris
Fractional advection-dispersion equations for1 modeling transport at the Earth surface2 Rina partial differential equations such as the advection-dispersion equation12 (ADE) begin with assumptions biomechanical transport and mixing29 by bioturbation, and the transport of sediment particles and sediment
Dispersion of swimming algae in laminar and turbulent channel flows: theory and simulations
Croze, O A; Ahmed, M; Bees, M A; Brandt, L
2012-01-01T23:59:59.000Z
Algal swimming is often biased by environmental cues, e.g. gravitational and viscous torques drive cells towards downwelling fluid (gyrotaxis). In view of biotechnological applications, it is important to understand how such biased swimming affects cell dispersion in a flow. Here, we study the dispersion of gyrotactic swimming algae in laminar and turbulent channel flows. By direct numerical simulation (DNS) of cell motion within upwelling and downwelling channel flows, we evaluate time-dependent measures of dispersion for increasing values of the flow Peclet (Reynolds) numbers, Pe (Re). Furthermore, we derive an analytical `swimming Taylor-Aris dispersion' theory, using flow-dependent transport parameters given by existing microscopic models. In the laminar regime, DNS results and analytical predictions compare very well, providing the first confirmation that cells' response to flow is best described by the generalized-Taylor-dispersion microscopic model. We predict that cells drift along a channel faster th...
Cryogenic properties of dispersion strengthened copper for high magnetic fields
Toplosky, V. J.; Han, K.; Walsh, R. P. [National High Magnetic Field Laboratory, Tallahassee, FL 32310 (United States); Swenson, C. A. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)
2014-01-27T23:59:59.000Z
Cold deformed copper matrix composite conductors, developed for use in the 100 tesla multi-shot pulsed magnet at the National High Magnetic Field Laboratory (NHMFL), have been characterized. The conductors are alumina strengthened copper which is fabricated by cold drawing that introduces high dislocation densities and high internal stresses. Both alumina particles and high density of dislocations provide us with high tensile strength and fatigue endurance. The conductors also have high electrical conductivities because alumina has limited solubility in Cu and dislocations have little scattering effect on conduction electrons. Such a combination of high strength and high conductivity makes it an excellent candidate over other resistive magnet materials. Thus, characterization is carried out by tensile testing and fully reversible fatigue testing. In tensile tests, the material exceeds the design criteria parameters. In the fatigue tests, both the load and displacement were measured and used to control the amplitude of the tests to simulate the various loading conditions in the pulsed magnet which is operated at 77 K in a non-destructive mode. In order to properly simulate the pulsed magnet operation, strain-controlled tests were more suitable than load controlled tests. For the dispersion strengthened coppers, the strengthening mechanism of the aluminum oxide provided better tensile and fatigue properties over convention copper.
The Impact of Dust Evolution and Photoevaporation on Disk Dispersal
Gorti, Uma; Dullemond, Cornelis
2015-01-01T23:59:59.000Z
Protoplanetary disks are dispersed by viscous evolution and photoevaporation in a few million years; in the interim small, sub-micron sized dust grains must grow and form planets. The time-varying abundance of small grains in an evolving disk directly affects gas heating by far-ultraviolet photons, while dust evolution affects photoevaporation by changing the disk opacity and resulting penetration of FUV photons in the disk. Photoevaporative flows, in turn, selectively carry small dust grains leaving the larger particles---which decouple from the gas---behind in the disk. We study these effects by investigating the evolution of a disk subject to viscosity, photoevaporation by EUV, FUV and X-rays, dust evolution, and radial drift using a 1-D multi-fluid approach (gas + different dust grain sizes) to solve for the evolving surface density distributions. The 1-D evolution is augmented by 1+1D models constructed at each epoch to obtain the instantaneous disk structure and determine photoevaporation rates. The imp...
Viscosity of alumina nanoparticles dispersed in car engine coolant
Kole, Madhusree; Dey, T.K. [Thermophysical Measurements Laboratory, Cryogenic Engineering Centre, Indian Institute of Technology, Kharagpur 721 302 (India)
2010-09-15T23:59:59.000Z
The present paper, describes our experimental results on the viscosity of the nanofluid prepared by dispersing alumina nanoparticles (<50 nm) in commercial car coolant. The nanofluid prepared with calculated amount of oleic acid (surfactant) was tested to be stable for more than 80 days. The viscosity of the nanofluids is measured both as a function of alumina volume fraction and temperature between 10 and 50 C. While the pure base fluid display Newtonian behavior over the measured temperature, it transforms to a non-Newtonian fluid with addition of a small amount of alumina nanoparticles. Our results show that viscosity of the nanofluid increases with increasing nanoparticle concentration and decreases with increase in temperature. Most of the frequently used classical models severely under predict the measured viscosity. Volume fraction dependence of the nanofluid viscosity, however, is predicted fairly well on the basis of a recently reported theoretical model for nanofluids that takes into account the effect of Brownian motion of nanoparticles in the nanofluid. The temperature dependence of the viscosity of engine coolant based alumina nanofluids obeys the empirical correlation of the type: log ({mu}{sub nf}) = A exp(BT), proposed earlier by Namburu et al. (author)
Acoustic dispersion in a two-dimensional dipole system
Golden, Kenneth I.; Kalman, Gabor J.; Donko, Zoltan; Hartmann, Peter [Department of Mathematics and Statistics, College of Engineering and Mathematical Sciences, University of Vermont, Burlington, Vermont 05401-1455 (United States); Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467 (United States); Research Institute for Solid State Physics and Optics of the Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary)
2008-07-15T23:59:59.000Z
We calculate the full density response function and from it the long-wavelength acoustic dispersion for a two-dimensional system of strongly coupled point dipoles interacting through a 1/r{sup 3} potential at arbitrary degeneracy. Such a system has no random-phase-approximation (RPA) limit and the calculation has to include correlations from the outset. We follow the quasilocalized charge (QLC) approach, accompanied by molecular-dynamics (MD) simulations. Similarly to what has been recently reported for the closely spaced classical electron-hole bilayer [G. J. Kalman et al., Phys. Rev. Lett. 98, 236801 (2007)] and in marked contrast to the RPA, we report a long-wavelength acoustic phase velocity that is wholly maintained by particle correlations and varies linearly with the dipole moment p. The oscillation frequency, calculated both in an extended QLC approximation and in the Singwi-Tosi-Land-Sjolander approximation [Phys. Rev. 176, 589 (1968)], is invariant in form over the entire classical to quantum domains all the way down to zero temperature. Based on our classical MD-generated pair distribution function data and on ground-state energy data generated by recent quantum Monte Carlo simulations on a bosonic dipole system [G. E. Astrakharchik et al., Phys. Rev. Lett. 98, 060405 (2007)], there is a good agreement between the QLC approximation kinetic sound speeds and the standard thermodynamic sound speeds in both the classical and quantum domains.
Particle dispersing system and method for testing semiconductor manufacturing equipment
Chandrachood, Madhavi (Sunnyvale, CA); Ghanayem, Steve G. (Sunnyvale, CA); Cantwell, Nancy (Milpitas, CA); Rader, Daniel J. (Albuquerque, NM); Geller, Anthony S. (Albuquerque, NM)
1998-01-01T23:59:59.000Z
The system and method prepare a gas stream comprising particles at a known concentration using a particle disperser for moving particles from a reservoir of particles into a stream of flowing carrier gas. The electrostatic charges on the particles entrained in the carrier gas are then neutralized or otherwise altered, and the resulting particle-laden gas stream is then diluted to provide an acceptable particle concentration. The diluted gas stream is then split into a calibration stream and the desired output stream. The particles in the calibration stream are detected to provide an indication of the actual size distribution and concentration of particles in the output stream that is supplied to a process chamber being analyzed. Particles flowing out of the process chamber within a vacuum pumping system are detected, and the output particle size distribution and concentration are compared with the particle size distribution and concentration of the calibration stream in order to determine the particle transport characteristics of a process chamber, or to determine the number of particles lodged in the process chamber as a function of manufacturing process parameters such as pressure, flowrate, temperature, process chamber geometry, particle size, particle charge, and gas composition.
Dispersion of radioactive pollutant in a tornadic storm
Pepper, D.W.
1981-05-01T23:59:59.000Z
A three-dimensional numerical model is used to calculate ground-level air concentration and deposition (due to precipitation scavenging) after a hypothetical tornado strike at a plutonium fabrication facility in Pennsylvania. Plutonium particles less than 10 ..mu..m in diameter are assumed to be lifted into the tornadic storm cell by the vortex. The rotational characteristics of the tornadic storm are embedded within the larger mesoscale flow of the storm system. The design-basis translational wind values are based on probabilities associated with existing records of tornado strikes in the vicinity of the plant site. Turbulence exchange coefficients are based on empirical values deduced from experimental data in severe storms and from theoretical assumptions obtained from the literature. The quasi-Lagrangian method of moments is used to model the transport of concentration within a grid cell volume. In all case studies, the effects of updrafts and downdrafts, coupled with scavenging of the particulates by precipitation, account for most of the material being deposited within 20 to 45 km downwind of the plant site. Ground-level isopleths in the x-y plane show that most of the material is deposited behind and slightly to the left of the centerline trajectory of the storm. Approximately 5% of the material is dispersed into the stratosphere and anvil section of the storm.
Do dispersive waves play a role in collisionless magnetic reconnection?
Liu, Yi-Hsin; Daughton, W.; Li, H. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Karimabadi, H. [SciberQuest, Del Mar, California 92014 (United States) [SciberQuest, Del Mar, California 92014 (United States); Department of Electrical and Computer Engineering, UCSD, La Jolla, California 92093 (United States); Peter Gary, S. [Space Science Institute, Boulder, Colorado 80301 (United States)] [Space Science Institute, Boulder, Colorado 80301 (United States)
2014-02-15T23:59:59.000Z
Using fully kinetic simulations, we demonstrate that the properly normalized reconnection rate is fast ?0.1 for guide fields up to 80× larger than the reconnecting field and is insensitive to both the system size and the ion to electron mass ratio. These results challenge conventional explanations of reconnection based on fast dispersive waves, which are completely absent for sufficiently strong guide fields. In this regime, the thickness of the diffusion layer is set predominantly by the electron inertial length with an inner sublayer that is controlled by finite gyro-radius effects. As the Alfvén velocity becomes relativistic for very strong guide fields, the displacement current becomes important and strong deviations from charge neutrality occur, resulting in the build-up of intense electric fields which absorb a portion of the magnetic energy release. Over longer time scales, secondary magnetic islands are generated near the active x-line while an electron inertial scale Kelvin-Helmholtz instability is driven within the outflow. These secondary instabilities give rise to time variations in the reconnection rate but do not alter the average value.
Dispersal of Gaseous Circumstellar Discs around High-Mass Stars
Yue Shen; Yu-Qing Lou
2006-05-19T23:59:59.000Z
We study the dispersal of a gaseous disc surrounding a central high-mass stellar core once this circumstellar disc becomes fully ionized. If the stellar and surrounding EUV and X-ray radiations are so strong as to rapidly heat up and ionize the entire circumstellar disc as further facilitated by disc magnetohydrodynamic (MHD) turbulence, a shock can be driven to travel outward in the fully ionized disc, behind which the disc expands and thins. For an extremely massive and powerful stellar core, the ionized gas pressure overwhelms the centrifugal and gravitational forces in the disc. In this limit, we construct self-similar shock solutions for such an expansion and depletion phase. As a significant amount of circumstellar gas being removed, the relic disc becomes vulnerable to strong stellar winds and fragments into clumps. We speculate that disc disappearance happens rapidly, perhaps on a timescale of $\\sim 10^3-10^4\\hbox{yr}$ once the disc becomes entirely ionized sometime after the onset of thermal nuclear burning in a high-mass stellar core.
Oxide Dispersion Strengthened Iron Aluminide by CVD Coated Powders
Asit Biswas Andrew J. Sherman
2006-09-25T23:59:59.000Z
This I &I Category2 program developed chemical vapor deposition (CVD) of iron, aluminum and aluminum oxide coated iron powders and the availability of high temperature oxidation, corrosion and erosion resistant coating for future power generation equipment and can be used for retrofitting existing fossil-fired power plant equipment. This coating will provide enhanced life and performance of Coal-Fired Boilers components such as fire side corrosion on the outer diameter (OD) of the water wall and superheater tubing as well as on the inner diameter (ID) and OD of larger diameter headers. The program also developed a manufacturing route for readily available thermal spray powders for iron aluminide coating and fabrication of net shape component by powder metallurgy route using this CVD coated powders. This coating can also be applid on jet engine compressor blade and housing, industrial heat treating furnace fixtures, magnetic electronic parts, heating element, piping and tubing for fossil energy application and automotive application, chemical processing equipment , heat exchanger, and structural member of aircraft. The program also resulted in developing a new fabrication route of thermal spray coating and oxide dispersion strengthened (ODS) iron aluminide composites enabling more precise control over material microstructures.
Dispersion relation for pure dust Bernstein waves in a non-Maxwellian magnetized dusty plasma
Deeba, F. [National Tokamak Fusion Program, PAEC, P.O. Box 3329, Islamabad 44000 (Pakistan); Department of Physics, G.C. University, Lahore 54000 (Pakistan); Ahmad, Zahoor [National Tokamak Fusion Program, PAEC, P.O. Box 3329, Islamabad 44000 (Pakistan); Murtaza, G. [Salam Chair in Physics, G.C. University, Lahore 54000 (Pakistan)
2011-07-15T23:59:59.000Z
Pure dust Bernstein waves are investigated using non-Maxwellian kappa and (r,q) distribution functions in a collisionless, uniform magnetized dusty plasma. Dispersion relations for both the distributions are derived by considering waves whose frequency is of the order of dust cyclotron frequency, and dispersion curves are plotted. It is observed that the propagation band for dust Bernstein waves is rather narrow as compared with that of the electron Bernstein waves. However, the band width increases for higher harmonics, for both kappa and (r,q) distributions. Effect of dust charge on dispersion curves is also studied, and one observes that with increasing dust charge, the dispersion curves shift toward the lower frequencies. Increasing the dust to ion density ratio ((n{sub d0}/n{sub i0})) causes the dispersion curve to shift toward the higher frequencies. It is also found that for large values of spectral index kappa ({kappa}), the dispersion curves approach to the Maxwellian curves. The (r,q) distribution approaches the kappa distribution for r = 0, whereas for r > 0, the dispersion curves show deviation from the Maxwellian curves as expected. Relevance of this work can be found in astrophysical plasmas, where non-Maxwellian velocity distributions as well as dust particles are commonly observed.
Federal Response Assets for a Radioactive Dispersal Device Incident
Sullivan,T.
2009-06-30T23:59:59.000Z
If a large scale RDD event where to occur in New York City, the magnitude of the problem would likely exceed the capabilities of City and State to effectively respond to the event. New York State could request Federal Assistance if the United States President has not already made the decision to provide it. The United States Federal Government has a well developed protocol to respond to emergencies. The National Response Framework (NRF) describes the process for responding to all types of emergencies including RDD incidents. Depending on the location and type of event, the NRF involves appropriate Federal Agencies, e.g., Department of Homeland Security (DHS), the Department of Energy (DOE), Environmental Protection Agency (EPA), United States Coast Guard (USCG), Department of Defense (DOD), Department of Justice (DOJ), Department of Agriculture (USDA), and Nuclear Regulatory Commission (NRC). The Federal response to emergencies has been refined and improved over the last thirty years and has been tested on natural disasters (e.g. hurricanes and floods), man-made disasters (oil spills), and terrorist events (9/11). However, the system has never been tested under an actual RDD event. Drills have been conducted with Federal, State, and local agencies to examine the initial (early) phases of such an event (TopOff 2 and TopOff 4). The Planning Guidance for Protection and Recovery Following Radiological Dispersal Device (RDD) and Improvised Nuclear Device (IND) incidents issued by the Department of Homeland Security (DHS) in August 2008 has never been fully tested in an interagency exercise. Recently, another exercise called Empire 09 that was situated in Albany, New York was conducted. Empire 09 consists of 3 different exercises be held in May and June, 2009. The first exercise, May 2009, involved a table top exercise for phase 1 (0-48 hours) of the response to an RDD incident. In early June, a full-scale 3- day exercise was conducted for the mid-phase response (48 hours +). A few weeks later, a one day full-scale exercise was conducted for the late phase (recovery) response to an RDD event. The lessons learned from this study are not available as of June 30, 2009. The objective of this report is to review and summarize anticipated Federal and State response actions and the roles and responsibilities of various agencies (DHS, EPA, DOE, NY-DEP, NY-DEC) with respect to decontamination issues that would arise from a radiological dispersion device (RDD), e.g., dirty bomb attack. These issues arise in the late phase of the response (48 hours and beyond) after the area has been stabilized and forensic information has been obtained. Much of the information provided in this report is taken directly from published guidance that is readily available.
Chertkov, Michael; Gabitov, Ildar
2004-03-02T23:59:59.000Z
The present invention provides methods and optical fibers for periodically pinning an actual (random) accumulated chromatic dispersion of an optical fiber to a predicted accumulated dispersion of the fiber through relatively simple modifications of fiber-optic manufacturing methods or retrofitting of existing fibers. If the pinning occurs with sufficient frequency (at a distance less than or are equal to a correlation scale), pulse degradation resulting from random chromatic dispersion is minimized. Alternatively, pinning may occur quasi-periodically, i.e., the pinning distance is distributed between approximately zero and approximately two to three times the correlation scale.
On the application of computational fluid dynamics codes for liquefied natural gas dispersion.
Luketa-Hanlin, Anay Josephine; Koopman, Ronald P. (Lawrence Livermore National Laboratory, Livermore, CA); Ermak, Donald (Lawrence Livermore National Laboratory, Livermore, CA)
2006-02-01T23:59:59.000Z
Computational fluid dynamics (CFD) codes are increasingly being used in the liquefied natural gas (LNG) industry to predict natural gas dispersion distances. This paper addresses several issues regarding the use of CFD for LNG dispersion such as specification of the domain, grid, boundary and initial conditions. A description of the k-{var_epsilon} model is presented, along with modifications required for atmospheric flows. Validation issues pertaining to the experimental data from the Burro, Coyote, and Falcon series of LNG dispersion experiments are also discussed. A description of the atmosphere is provided as well as discussion on the inclusion of the Coriolis force to model very large LNG spills.
Dispersion engineering of high-Q silicon microresonators via thermal oxidation
Jiang, Wei C. [Institute of Optics, University of Rochester, Rochester, New York 14627 (United States); Zhang, Jidong [Department of Electrical and Computer Engineering, University of Rochester, Rochester, New York 14627 (United States); Usechak, Nicholas G. [Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States); Lin, Qiang, E-mail: qiang.lin@rochester.edu [Institute of Optics, University of Rochester, Rochester, New York 14627 (United States); Department of Electrical and Computer Engineering, University of Rochester, Rochester, New York 14627 (United States)
2014-07-21T23:59:59.000Z
We propose and demonstrate a convenient and sensitive technique for precise engineering of group-velocity dispersion in high-Q silicon microresonators. By accurately controlling the surface-oxidation thickness of silicon microdisk resonators, we are able to precisely manage the zero-dispersion wavelength, while simultaneously further improving the high optical quality of our devices, with the optical Q close to a million. The demonstrated dispersion management allows us to achieve parametric generation with precisely engineerable emission wavelengths, which shows great potential for application in integrated silicon nonlinear and quantum photonics.
Dispersion engineering of high-Q silicon microresonators via thermal oxidation
Jiang, Wei C; Usechak, Nicholas G; Lin, Qiang
2014-01-01T23:59:59.000Z
We propose and demonstrate a convenient and sensitive technique for precise engineering of group-velocity dispersion in high-Q silicon microresonators. By accurately controlling the surface-oxidation thickness of silicon microdisk resonators, we are able to precisely manage the zero-dispersion wavelength while simultaneously further improving the high optical quality of our devices, with the optical Q close to a million. The demonstrated dispersion management allows us to achieve parametric generation with precisely engineerable emission wavelengths, which shows great potential for application in integrated silicon nonlinear and quantum photonics.
Self-similar pulse evolution in an all-normal-dispersion laser
Renninger, William H.; Chong, Andy; Wise, Frank W. [Department of Applied Physics, Cornell University, 212 Clark Hall, Ithaca, New York 14853 (United States)
2010-08-15T23:59:59.000Z
Parabolic amplifier similaritons are observed inside a normal-dispersion laser. The self-similar pulse is a local nonlinear attractor in the gain segment of the oscillator. The evolution in the laser exhibits large (20 times) spectral breathing, and the pulse chirp is less than the group-velocity dispersion of the cavity. All of these features are consistent with numerical simulations. The amplifier similariton evolution also yields practical features such as parabolic output pulses with high energies, and the shortest pulses to date from a normal-dispersion laser.
Li, Tim
Tropical Cyclogenesis Associated with Rossby Wave Energy Dispersion of a Preexisting Typhoon. Part with the Rossby wave energy dispersion of a preexisting TC. The wave trains are oriented in a northwest induced by tropical cyclone (TC) energy dispersion are revealed based on the Quick Scatterometer (Quik
Alternating projections on manifolds
2006-07-27T23:59:59.000Z
Jul 27, 2006 ... The survey ar- ticle [BB96] covers ... ?School of Operations Research and Industrial Engineering, Cornell University, Ithaca,. NY 14853, U.S.A. ...
Deeba, F. [National Tokamak Fusion Program, PAEC, P.O. Box 3329, Islamabad 44000 (Pakistan); Department of Physics, G. C. University, Lahore 54000 (Pakistan); Ahmad, Zahoor [National Tokamak Fusion Program, PAEC, P.O. Box 3329, Islamabad 44000 (Pakistan); Murtaza, G. [Salam Chair in Physics, G. C. University, Lahore 54000 (Pakistan)
2010-10-15T23:59:59.000Z
A generalized dielectric constant for the electron Bernstein waves using non-Maxwellian distribution functions is derived in a collisionless, uniform magnetized plasma. Using the Neumann series expansion for the products of Bessel functions, we can derive the dispersion relations for both kappa and the generalized (r,q) distributions in a straightforward manner. The dispersion relations now become dependent upon the spectral indices {kappa} and (r,q) for the kappa and the generalized (r,q) distribution, respectively. Our results show how the non-Maxwellian dispersion curves deviate from the Maxwellian depending upon the values of the spectral indices chosen. It may be noted that the (r,q) dispersion relation is reduced to the kappa distribution for r=0 and q={kappa}+1, which, in turn, is further reducible to the Maxwellian distribution for {kappa}{yields}{infinity}.
Etika, Krishna
2012-02-14T23:59:59.000Z
state. The ability to tailor nanoparticle dispersion state in liquid and solid media can ultimately provide a powerful method for tailoring the properties of solution processed nanoparticle-filled polymer composites. This dissertation reports the use...
FRICTION AND WEAR STUDY OF DISPERSED PHASE INTERMETALLIC COMPOUNDS IN FERROUS MATRICES
Riddle, R.A.
2010-01-01T23:59:59.000Z
rights. .j . J LBL-5771 FRICTION AND WEAR STUDY OF DISPERSEDS. THESIS) i LBL-5771 FRICTION AND WEAR STUDY OF DISPERSEDWilman, "A Theory of Friction and Wear During the Abrasion
The evolution of dispersion in the sibilants of the Scandinavian languages
Williams, Paul Jonathan
2012-11-28T23:59:59.000Z
This dissertation investigates the evolution of dispersion in sound inventories by extending Boersma & Hamann’s (2008) model to the sibilant inventories of some of the modern Scandinavian languages. I show that the Icelandic and central Swedish...
Crab dispersion and its impact on the CERN Large Hadron Collider collimation
Sun, P; Tomàs, R; Zimmermann, F
2010-01-01T23:59:59.000Z
Crab cavities are proposed to be used for a luminosity upgrade of the Large Hadron Collider (LHC). Crab cavities are rf cavities operated in a transverse dipole mode, which imparts on the beam particles a transverse kick that varies with the longitudinal position along the bunch. The crab cavity introduces another kind of dispersion to the particles which is z dependent, and thus could complicate the beam dynamics and have an impact on the LHC collimation system. As for LHC, the off-momentum beta-beat and dispersion-beat already compromise the performance of the collimation system; the crab dispersion introduced by global crab cavities might do the same, and should be carefully evaluated. In this paper, we present a definition for the crab dispersion, and study its impact on the LHC collimation system.
Lee, Sunwoong
2006-01-01T23:59:59.000Z
Methods are developed for passive source localization and environmental parameter estimation in seismo-acoustic waveguides by exploiting the dispersive behavior of guided wave propagation. The methods developed are applied ...
Phillips, Holly Anne
2009-05-15T23:59:59.000Z
The threat of a Radiological Dispersal Device (RDD) detonation arouses the concern of contaminated victims of all ages. The purpose of this study was to investigate the dose to a uniformly contaminated five-year old male. It also explores...
Mruczkiewicz, M.; Krawczyk, M. [Faculty of Physics, Adam Mickiewicz University in Poznan, Umultowska 85, Pozna? 61-614 (Poland)
2014-03-21T23:59:59.000Z
We study the effect of one-side metallization of a uniform ferromagnetic thin film on its spin-wave dispersion relation in the Damon–Eshbach geometry. Due to the finite conductivity of the metallic cover layer on the ferromagnetic film, the spin-wave dispersion relation may be nonreciprocal only in a limited wave-vector range. We provide an approximate analytical solution for the spin-wave frequency, discuss its validity, and compare it with numerical results. The dispersion is analyzed systematically by varying the parameters of the ferromagnetic film, the metal cover layer and the value of the external magnetic field. The conclusions drawn from this analysis allow us to define a structure based on a 30?nm thick CoFeB film with an experimentally accessible nonreciprocal dispersion relation in a relatively wide wave-vector range.
Application of Computational Fluid Dynamics in the Forced Dispersion Modeling of LNG Vapor Clouds
Kim, Byung-Kyu
2013-05-31T23:59:59.000Z
The safety and security of liquefied natural gas (LNG) facilities has prompted the need for continued study of LNG mitigation systems. Water spray systems are widely recognized as an effective measure for dispersing LNG vapor clouds. Currently...
Study of the Effects of Obstacles in Liquefied Natural Gas (LNG) Vapor Dispersion using CFD Modeling
Ruiz Vasquez, Roberto
2012-10-19T23:59:59.000Z
The evaluation of the potential hazards related with the operation of an LNG terminal includes possible release scenarios with the consequent flammable vapor dispersion within the facility; therefore, it is important to know the behavior...
Liquefied Natural Gas (LNG) Vapor Dispersion Modeling with Computational Fluid Dynamics Codes
Qi, Ruifeng
2012-10-19T23:59:59.000Z
Federal regulation 49 CFR 193 and standard NFPA 59A require the use of validated consequence models to determine the vapor cloud dispersion exclusion zones for accidental liquefied natural gas (LNG) releases. For modeling purposes, the physical...
Air dispersion modeling of particulate matter from ground-level area sources
Meister, Michael Todd
2000-01-01T23:59:59.000Z
State Air Pollution Regulatory Agencies (SAPRAs) often use dispersion modeling to predict downwind concentrations of particulate matter (PM) from a facility. As such, a facility may be granted or denied an operating permit ...
Rehman, Abdul
2012-02-14T23:59:59.000Z
This thesis provides a detailed evaluation of different environmentally friendly dispersants in invert-emulsion drilling fluids that can be used to drill wells under difficult conditions such as HPHT. The drilling fluid is weighted by manganese...
Jabloner, H.
1987-07-07T23:59:59.000Z
A cutback asphalt composition is described comprising asphalt and a hydrocarbon solvent. The improvement composition comprises a water-dispersible spurted polyolefin pulp having precipitated a natural rubber or synthetic elastomer that is swellable in hydrocarbon solvents.
Control of Vapor Dispersion and Pool Fire of Liquefied Natural Gas (LNG) with Expansion Foam
Yun, Geun Woong
2011-10-21T23:59:59.000Z
in outdoor field tests. Thus, this research focused on experimental determination of the effect of expansion foam application on LNG vapor dispersion and pool fire. Specifically, for evaluating the use of foam to control the vapor hazard from spilled LNG...
A numerical study of horizontal dispersion in a macro tidal basin
Maine, University of
boundary layer near the tidal mixing front on Georges Bank (Houghton and Ho 2001) and in Hudson River that significant horizon- tal dispersion and mixing can be induced in oscillatory flows (Aref 1984; Ottino 1989
Type Ia Supernova Intrinsic Magnitude Dispersion and the Fitting of Cosmological Parameters
Kim, Alex G
2010-12-10T23:59:59.000Z
I present an analysis for fitting cosmological parameters from a Hubble Diagram of a standard candle with unknown intrinsic magnitude dispersion. The dispersion is determined from the data themselves, simultaneously with the cosmological parameters. This contrasts with the strategies used to date. The advantages of the presented analysis are that it is done in a single fit (it is not iterative), it provides a statistically founded and unbiased estimate of the intrinsic dispersion, and its cosmological-parameter uncertainties account for the intrinsic dispersion uncertainty. Applied to Type Ia supernovae, my strategy provides a statistical measure to test for sub-types and assess the significance of any magnitude corrections applied to the calibrated candle. Parameter bias and differences between likelihood distributions produced by the presented and currently-used fitters are negligibly small for existing and projected supernova data sets.
Cirpka, Olaf Arie
Geostatistical inference of hydraulic conductivity and dispersivities from hydraulic heads; accepted 25 April 2006; published 10 August 2006. [1] In groundwater, hydraulic heads and solute arrival times depend primarily on the hydraulic conductivity field and hydraulic boundary conditions. The spread
Shear wave attenuation and dispersion in melt-bearing olivine polycrystals
interpretation and seismological implications Ulrich H. Faul, John D. Fitz Gerald, and Ian Jackson Research: seismic wave attenuation, olivine, partial melting, grain boundary sliding, grain boundary structure and dispersion in melt-bearing olivine polycrystals: 2. Microstructural interpretation and seismological
Engineering Escherichia coli to Control Biofilm Formation, Dispersal, and Persister Cell Formation
Hong, Seok Hoon
2012-02-14T23:59:59.000Z
was obtained that causes nearly complete biofilm dispersal by increasing cell death by the activation of proteases. Bacterial quorum sensing (QS) systems are important components of a wide variety of engineered biological devices, since autoinducers are useful...
Diversity and productivity peak at intermediate dispersal rate in evolving metacommunities
Hochberg, Michael
LETTERS Diversity and productivity peak at intermediate dispersal rate in evolving metacommunities * Positive relationships between species diversity and productivity have been reported for a number of understanding how diversity and productivity are linked over evolutionary timescales. Here, we investigate
Hamilton, Andrea; Hall, Christopher
2008-01-01T23:59:59.000Z
We describe an unusual application of synchrotron energy-dispersive diffraction with hard X-rays to obtain structural information on metastable sodium sulfate heptahydrate. This hydrate was often mentioned in nineteenth ...
Price, Jacqueline Elaine
2004-11-15T23:59:59.000Z
backward Lagrangian stochastic model and a Gaussian plume dispersion model. This analysis assessed the uncertainty surrounding each sampling procedure in order to gain a better understanding of the uncertainty in the final emission rate calculation (a basis...
Fitting Tweedie's Compound Poisson Model to Insurance Claims Data: Dispersion Modelling
Smyth, Gordon K.
. Smyth Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia Bent Jørgensen, dispersion modelling, double generalized linear models, power variance function, REML, risk theory of Medical Research, Post Office, Royal Melbourne Hospital, Parkville, VIC 3050, Australia 1 #12
12.141 Electron Microprobe Analysis by Wavelength Dispersive X-ray Spectrometry, January (IAP) 2006
Chatterjee, Nilanjan
Introduction to the theory of x-ray microanalysis through the electron microprobe including ZAF matrix corrections. Techniques to be discussed are wavelength and energy dispersive spectrometry, scanning backscattered ...
Thermal non-equilibrium in dispersed flow film boiling in a vertical tube
Forslund, Robert Paul
1966-01-01T23:59:59.000Z
The departure from thermal equilibrium between a dispersed liquid phase and its vapor at high quality during film boiling is investigated, The departure from equilibruim is manifested by the high resistance to heat transfer ...
Localized in-situ polymerization on graphene surfaces for stabilized graphene dispersions
Sriya Das; Ahmed S. Wajid; John L. Shelburne; Yen-Chi Liao; Micah J. Green
2011-04-28T23:59:59.000Z
We demonstrate a novel in situ polymerization technique to develop localized polymer coatings on the surface of dispersed pristine graphene sheets. Graphene sheets show great promise as strong, conductive fillers in polymer nanocomposites; however, difficulties in dispersion quality and interfacial strength between filler and matrix have been a persistent problem for graphene-based nanocomposites, particularly for pristine graphene. To address this problem, a physisorbed polymer layer is used to stabilize graphene sheets in solution. To form this protective layer, an organic microenvironment is formed around dispersed graphene sheets in surfactant solutions, and a nylon 6,10 or nylon 6,6 coating is created via interfacial polymerization. A similar technique was originally developed to protect luminescent properties of carbon nanotubes in solution. These coated graphene dispersions are aggregation-resistant and may be reversibly redispersed in water even after freeze-drying. The coated graphene holds promise for a number of applications, including multifunctional graphene-polymer nanocomposites.
Truong, Bao H. (Bao Hoai)
2008-01-01T23:59:59.000Z
Nanofluids are engineered colloidal dispersions of nanoparticles (1-100nm) in common fluids (water, refrigerants, or ethanol...). Materials used for nanoparticles include chemically stable metals (e.g., gold, silver, ...
Price, Jacqueline Elaine
2004-11-15T23:59:59.000Z
Engineering directly impacts current and future regulatory policy decisions. The foundation of air pollution control and air pollution dispersion modeling lies in the math, chemistry, and physics of the environment. ...
Study of the Effects of Obstacles in Liquefied Natural Gas (LNG) Vapor Dispersion using CFD Modeling
Ruiz Vasquez, Roberto
2012-10-19T23:59:59.000Z
The evaluation of the potential hazards related with the operation of an LNG terminal includes possible release scenarios with the consequent flammable vapor dispersion within the facility; therefore, it is important to ...
Iterative receivers for OFDM systems with dispersive fading and frequency offset
Liu, Hui
2004-09-30T23:59:59.000Z
The presence of dispersive fading and inter-carrier interference (ICI) constitute the major impediment to reliable communications in orthogonal frequency-division multiplexing (OFDM) systems. Recently iterative (``Turbo'') processing techniques...
Calabro, Joshua D.
Fundamental to the development of three-dimensional microelectronic fabrication is a material that enables vertical geometries. Here we show low-melting-point metal alloys containing iron dispersions that can be remotely ...
Process for the synthesis of nanophase dispersion-strengthened aluminum alloy
Barbour, John C. (Albuquerque, NM); Knapp, James Arthur (Albuquerque, NM); Follstaedt, David Martin (Albuquerque, NM); Myers, Samuel Maxwell (Albuquerque, NM)
1998-12-15T23:59:59.000Z
A process for fabricating dispersion-strengthened ceramic-metal composites is claimed. The process comprises in-situ interaction and chemical reaction of a metal in gaseous form with a ceramic producer in plasma form. Such composites can be fabricated with macroscopic dimensions. Special emphasis is placed on fabrication of dispersion-strengthened aluminum oxide-aluminum composites, which can exhibit flow stresses more characteristic of high strength steel.
Origin of Scale-Dependent Dispersivity and Its Implications For Miscible Gas Flooding
Steven Bryant; Russ Johns; Larry Lake; Thomas Harmon
2008-09-30T23:59:59.000Z
Dispersive mixing has an important impact on the effectiveness of miscible floods. Simulations routinely assume Fickian dispersion, yet it is well established that dispersivity depends on the scale of measurement. This is one of the main reasons that a satisfactory method for design of field-scale miscible displacement processes is still not available. The main objective of this project was to improve the understanding of the fundamental mechanisms of dispersion and mixing, particularly at the pore scale. To this end, microsensors were developed and used in the laboratory to measure directly the solute concentrations at the scale of individual pores; the origin of hydrodynamic dispersion was evaluated from first principles of laminar flow and diffusion at the grain scale in simple but geometrically completely defined porous media; techniques to use flow reversal to distinguish the contribution to dispersion of convective spreading from that of true mixing; and the field scale impact of permeability heterogeneity on hydrodynamic dispersion was evaluated numerically. This project solved a long-standing problem in solute transport in porous media by quantifying the physical basis for the scaling of dispersion coefficient with the 1.2 power of flow velocity. The researchers also demonstrated that flow reversal uniquely enables a crucial separation of irreversible and reversible contributions to mixing. The interpretation of laboratory and field experiments that include flow reversal provides important insight. Other advances include the miniaturization of long-lasting microprobes for in-situ, pore-scale measurement of tracers, and a scheme to account properly in a reservoir simulator (grid-block scale) for the contributions of convective spreading due to reservoir heterogeneity and of mixing.
Dispersion engineered high-Q silicon Nitride Ring-Resonators via Atomic Layer Deposition
Riemensberger, Johann; Herr, Tobias; Brasch, Victor; Holzwarth, Ronald; Kippenberg, Tobias J
2012-01-01T23:59:59.000Z
We demonstrate dispersion engineering of integrated silicon nitride based ring resonators through conformal coating with hafnium dioxide deposited on top of the structures via atomic layer deposition (ALD). Both, magnitude and bandwidth of anomalous dispersion can be significantly increased. All results are confirmed by high resolution frequency-comb-assisted-diode-laser spectroscopy and are in very good agreement with the simulated modification of the mode spectrum.
Method for in situ characterization of a medium of dispersed matter in a continuous phase
Kaufman, Eric N. (Knoxville, TN)
1995-01-01T23:59:59.000Z
A method for in situ characterization of a medium of a dispersed phase in a continuous phase, including the steps of adding a fluorescent dye to one phase capable of producing fluorescence therein when the fluorescent dye is optically excited, optically exciting the fluorescent dye at a wavelength to produce fluorescence in the one phase, and monitoring the fluorescence to distinguish the continuous phase from the dispersed phase.
Plasma-chemical production of dispersed carbon. study of the phase composition
Idinov, N.A.; Korolev, Y.M.; Polak, L.S.; Popov, V.T.
1986-09-01T23:59:59.000Z
Results of x-ray structure and electron-micoscope studies of plasma-chemical dispersed carbon particles obtained in an experiment are presented along with the results of an analysis of of the spectral composition of extracts from them. Experimental dependences of the properties of the dispersed carbon (size of clusters in particles, concentrations of polyaromatic compounds contained in the extracts, particle size distributions) on the temperature of the flow at the sampling point are obtained.
Characterizing the global dispersion of carbon nanotubes in ceramic matrix nanocomposites
Koszor, Orsolya; Tapaszto, Levente; Balazsi, Csaba [Research Institute for Technical Physics and Materials Science, H-1525 Budapest (Hungary); Marko, Marton [Research Institute for Solid State Physics and Optics, H-1525 Budapest (Hungary)
2008-11-17T23:59:59.000Z
The dispersion of single-walled carbon nanotubes in silicon nitride ceramic matrices has been investigated by small angle neutron scattering experiments. In contrast to electron microscopy investigations of fracture surfaces, neutron scattering measurements provide information on the bulk dispersion of nanotubes within the matrix. The scattering intensities reveal a decay exponent characteristic to surface fractals, which indicates that the predominant part of nanotubes can be found in loose networks surrounding the grains of the polycrystalline matrix.
An Algorithm for Detecting Quantum-Gravity Photon Dispersion in Gamma-Ray Bursts: DISCAN
Jeffrey D. Scargle; Jay P. Norris; Jerry T. Bonnell
2007-09-01T23:59:59.000Z
DisCan is a new algorithm implementing photon dispersion cancellation in order to measure energy-dependent delays in variable sources. This method finds the amount of reversed dispersion that optimally cancels any actual dispersion present. It applies to any time- and energy-tagged photon data, and can avoid binning in both time and energy. The primary motivation here is the search for quantum gravity based dispersion in future gamma ray burst data from the Gamma Ray Large Area Space Telescope (GLAST). Extrapolation of what is know about bursts at lower energies yields a reasonable prospect that photon dispersion effects consistent with some quantum gravity formalisms may be detected in sufficiently bright bursts. Short bursts have no or very small inherent lags, and are therefore better prospects than long ones, but even they suffer systematic error due to pulse asymmetry that may yield an irreducible uncertainty. We note that data at energies higher than about 0.1 TeV may not be useful for detecting dispersion in GRBs. Of several variants of the proposed algorithm, one based on Shannon information is consistently somewhat superior to all of the others we investigated.
Upscaling of Solute Transport in Heterogeneous Media with Non-uniform Flow and Dispersion Fields
Xu, Zhijie; Meakin, Paul
2013-10-01T23:59:59.000Z
An analytical and computational model for non-reactive solute transport in periodic heterogeneous media with arbitrary non-uniform flow and dispersion fields within the unit cell of length ? is described. The model lumps the effect of non-uniform flow and dispersion into an effective advection velocity Ve and an effective dispersion coefficient De. It is shown that both Ve and De are scale-dependent (dependent on the length scale of the microscopic heterogeneity, ?), dependent on the Péclet number Pe, and on a dimensionless parameter ? that represents the effects of microscopic heterogeneity. The parameter ?, confined to the range of [-0.5, 0.5] for the numerical example presented, depends on the flow direction and non-uniform flow and dispersion fields. Effective advection velocity Ve and dispersion coefficient De can be derived for any given flow and dispersion fields, and . Homogenized solutions describing the macroscopic variations can be obtained from the effective model. Solutions with sub-unit-cell accuracy can be constructed by homogenized solutions and its spatial derivatives. A numerical implementation of the model compared with direct numerical solutions using a fine grid, demonstrated that the new method was in good agreement with direct solutions, but with significant computational savings.
Impact of dispersed solar and wind systems on electric distribution planning and operation
Boardman, R.W.; Patton, R.; Curtice, D.H.
1981-02-01T23:59:59.000Z
Small-scale dispersed solar photovoltaic and wind generation (DSW) will affect the generation, transmission, and distribution systems of an electric utility. This study examines the technical and economic impacts of dispersing DSW devices within the distribution system. Dispersed intermittent generation is included. Effects of DSW devices on capital investments, reliability, operating and maintenance costs, protection requirements, and communication and control requirements are examined. A DSW operation model is developed to help determine the dependable capacity of fluctuating solar photovoltaic and wind generation as part of the distribution planning process. Specific case studies using distribution system data and renewable resource data for Southern California Edison Company and Consumers Power Company are analyzed to gain insights into the effects of interconnecting DSW devices. The DSW devices were found to offer some distribution investment savings, depending on their availability during peak loads. For a summer-peaking utility, for example, dispersing photovoltaic systems is more likely to defer distribution capital investments than dispersing wind systems. Dispersing storage devices to increase DSW's dependable capacity for distribution systems needs is not economically attractive. Substation placement of DSW and storage devices is found to be more cost effective than feeder or customer placement. Examination of the effects of DSW on distribution system operation showed that small customer-owned DSW devices are not likely to disrupt present time-current distribution protection coordination. Present maintenance work procedures, are adequate to ensure workmen's safety. Regulating voltages within appropriate limits will become more complex with intermittent generation along the distribution feeders.
The role of surface structure and dispersion in CO hydrogenation on cobalt
Johnson, B.G.; Bartholomew, C.H. (Brigham Young Univ., Provo, UT (USA)); Goodman, D.W. (Texas A and M Univ., College Station (USA))
1991-03-01T23:59:59.000Z
The effects of surface structure on the CO hydrogenation reaction have been investigated by comparing the steady-state activity and selectivity of submonolayer cobalt deposited on W(110) and W(100) with those of carbonyl-derived Co/alumina catalysts of varying dispersion and extent of reduction. The Co/W surfaces have highly strained and different geometries (1) but have similar activity. The activity matches that of the highly active, highly reduced Co/alumina catalysts, suggesting that the steady-state activity of cobalt surfaces is independent of surface structure. AES spectra show the after-reaction Co/W surfaces to have high coverages of both carbon and oxygen, with carbon lineshapes characteristic of carbidic carbon. Carbonyl-derived Co/dehydroxylated alumina catalysts have high extents of reduction, high dispersions, and good activity stability. Increasing the dehydroxylation temperature of the alumina support increases metal dispersion while decreasing CO{sub 2} and olefin selectivities. Specific CO hydrogenation activity is constant over the range of dispersion of 5-37% for highly reduced 3 and 5% Co/alumina catalysts and over the entire range of dispersion (0-100%) if polycrystalline Co and Co/W surfaces are included. The specific activity of carbonyl-derived catalysts appears to be more closely related to the extent of reduction and the support dehydroxylation temperature than to the dispersion. Thus, the chemical nature of the support surface appears to be the controlling factor in determining the specific activity of supported cobalt catalysts.
Raffray, A. René
2009-01-01T23:59:59.000Z
considerations) to enable coupling to an oxide dispersion-strengthened (ODS) ferritic steel manifold, to 1300 C
Raffray, A. René
2014-01-01T23:59:59.000Z
, assembly and maintenance, Fusion Eng. Des. (2014), http://dx.doi.org/10.1016/j.fusengdes.2014.elsevier.com/locate/fusengdes ITER blanket manifold system: Integration, assembly and maintenance Alex Martina, , George Dellopoulosb failure would prevent ITER operation a maintenance strategy has been planned. © 2014 Elsevier B.V. All
Observation of time dependent dispersion in laboratory scale experiments with intact tuff
Rundberg, R.S.; Triay, I.R.; Ott, M.A.; Mitchell, A.J.
1989-12-01T23:59:59.000Z
The migration of radionuclides through intact tuff was studied using tuff from Yucca Mountain, Nevada. The tuff samples were both highly zeolitized ash-fall tuff from the Calico Hills and densely welded devitrified tuff from the Topopah Springs member of the Paintbrush tuff. Tritiated water and pertechnetate were used as conservative tracers. The sorbing tracers {sup 85}Sr, {sup 137}Cs, and {sup 133}Ba were used with the devitrified tuff only. Greater tailing in the elution curves of the densely welded tuff samples was observed that could be fit by adjusting the dispersion coefficient in the conventional Advection Dispersion Equation, ADE. The curves could be fit using time dependent dispersion as was previously observed for sediments and alluvium by Dieulin, Matheron, and de Marsily. The peak of strontium concentration was expected to arrive after 1.5 years based on the conventional ADE and assuming a linear K{sub d} of 26 ml/g. The observed elution had significant strontium in the first sample taken at 2 weeks after injection. The peak in the strontium elution occurred at 5 weeks. The correct arrival time for the strontium peak was achieved using a one dimensional analytic solution with time dependent dispersion. The dispersion coefficient as a function of time used to fit the conservative tracers was found to predict the peak arrival of the sorbing tracers. The K{sub d} used was the K{sub d} determined by the batch method on crushed tuff. 23 refs., 9 figs., 2 tabs.
Analysis Of Residence Time Distribution Of Fluid Flow By Axial Dispersion Model
Sugiharto [Department of Physics, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Jl. Ganesha 10, Bandung 40132 (Indonesia); Centre for Applications of Isotopes and Radiation Technology-National Nuclear Energy Agency, Jl. Lebak Bulus Raya No. 49, Jakarta 12440 (Indonesia); Su'ud, Zaki; Kurniadi, Rizal; Waris, Abdul [Centre for Applications of Isotopes and Radiation Technology-National Nuclear Energy Agency, Jl. Lebak Bulus Raya No. 49, Jakarta 12440 (Indonesia); Abidin, Zainal [Department of Physics, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Jl. Ganesha 10, Bandung 40132 (Indonesia)
2010-12-23T23:59:59.000Z
Radioactive tracer {sup 82}Br in the form of KBr-82 with activity {+-} 1 mCi has been injected into steel pipeline to qualify the extent dispersion of water flowing inside it. Internal diameter of the pipe is 3 in. The water source was originated from water tank through which the water flow gravitically into the pipeline. Two collimated sodium iodide detectors were used in this experiment each of which was placed on the top of the pipeline at the distance of 8 and 11 m from injection point respectively. Residence time distribution (RTD) curves obtained from injection of tracer are elaborated numerically to find information of the fluid flow properties. The transit time of tracer calculated from the mean residence time (MRT) of each RTD curves is 14.9 s, therefore the flow velocity of the water is 0.2 m/s. The dispersion number, D/uL, for each RTD curve estimated by using axial dispersion model are 0.055 and 0.06 respectively. These calculations are performed after fitting the simulated axial dispersion model on the experiment curves. These results indicated that the extent of dispersion of water flowing in the pipeline is in the category of intermediate.
Ungulate Carcasses Perforate Ecological Filters and Create
and others 2005; Gilliam 2007; Dearden and War- dle 2008). Under some conditions, persistent dominant
Jha, Neetu; Ramaprabhu, S. [Department of Physics, Alternative Energy and Nanotechnology Laboratory (AENL), Nano Functional Materials Technology Centre (NFMTC), Indian Institute of Technology Madras, Chennai 600036 (India)
2009-10-15T23:59:59.000Z
High thermal conducting metal nanoparticles have been dispersed on the multiwalled carbon nanotubes (MWNTs) outer surface. Structural and morphological characterizations of metal dispersed MWNTs have been carried out using x-ray diffraction analysis, high resolution transmission electron microscopy, energy dispersive x-ray analysis, and Fourier transform infrared spectroscopy. Nanofluids have been synthesized using metal-MWNTs in de-ionized water (DI water) and ethylene glycol (EG) base fluids. It has been observed that nanofluids maintain the same sequence of thermal conductivity as that of metal nanoparticles Ag-MWNTs>Au-MWNTs>Pd-MWNTs. A maximum enhancement of 37.3% and 11.3% in thermal conductivity has been obtained in Ag-MWNTs nanofluid with DI water and EG as base fluids, respectively, at a volume fraction of 0.03%. Temperature dependence study also shows enhancement of thermal conductivity with temperature.
Nonlinear theory of resonant slow waves in anisotropic and dispersive plasmas
Christopher Clack; Istvan Ballai
2008-08-23T23:59:59.000Z
The solar corona is a typical example of a plasma with strongly anisotropic transport processes. The main dissipative mechanisms in the solar corona acting on slow magnetoacoustic waves are the anisotropic thermal conductivity and viscosity. Ballai et al. [Phys. Plasmas 5, 252 (1998)] developed the nonlinear theory of driven slow resonant waves in such a regime. In the present paper the nonlinear behaviour of driven magnetohydrodynamic waves in the slow dissipative layer in plasmas with strongly anisotropic viscosity and thermal conductivity is expanded by considering dispersive effects due to Hall currents. The nonlinear governing equation describing the dynamics of nonlinear resonant slow waves is supplemented by a term which describes nonlinear dispersion and is of the same order of magnitude as nonlinearity and dissipation. The connection formulae are found to be similar to their non-dispersive counterparts.
Temporally propagated optical pulses, and what they reveal about dispersion handling
Kinsler, Paul
2015-01-01T23:59:59.000Z
I derive a temporally propagated uni-directional optical pulse equation valid in the few cycle limit. Temporal propagation is advantageous because it naturally preserves causality, unlike the competing spatially propagated models. The approach generates exact coupled bi-directional equations, which can be efficiently approximated down to a uni-directional form in cases where an optical pulse changes little over one optical cycle. It also also allows a direct term-to-term comparison of an exact bi-directional theory with an approximate uni-directional theory. Notably, temporal propagation handles dispersion in a different way, and this difference serves to highlight existing approximations inherent in spatially propagated treatments of dispersion. Accordingly, I emphasise the need for future work in clarifying the limitations of the dispersion conversion required by these types of approaches; since the only alternative in the few cycle limit may be to resort to the much more computationally intensive full Maxw...
Method of producing an oxide dispersion strengthened coating and micro-channels
Kang, Bruce S; Chyu, Minking K; Alvin, Mary Anne; Gleeson, Brian M
2013-12-17T23:59:59.000Z
The disclosure provides a method for the production of composite particles utilizing a mechano chemical bonding process following by high energy ball milling on a powder mixture comprised of coating particles, first host particles, and second host particles. The composite particles formed have a grain size of less than one micron with grains generally characterized by a uniformly dispersed coating material and a mix of first material and second material intermetallics. The method disclosed is particularly useful for the fabrication of oxide dispersion strengthened coatings, for example using a powder mixture comprised of Y.sub.2O.sub.3, Cr, Ni, and Al. This particular powder mixture may be subjected to the MCB process for a period generally less than one hour following by high energy ball milling for a period as short as 2 hours. After application by cold spraying, the composite particles may be heat treated to generate an oxide-dispersion strengthened coating.
Tavlarides, L.L.; Bae, J.H.
1991-12-24T23:59:59.000Z
A laser capillary spectrophotometric technique measures real time or near real time bivariate drop size and concentration distribution for a reactive liquid-liquid dispersion system. The dispersion is drawn into a precision-bore glass capillary and an appropriate light source is used to distinguish the aqueous phase from slugs of the organic phase at two points along the capillary whose separation is precisely known. The suction velocity is measured, as is the length of each slug from which the drop free diameter is calculated. For each drop, the absorptivity at a given wavelength is related to the molar concentration of a solute of interest, and the concentration of given drops of the organic phase is derived from pulse heights of the detected light. This technique permits on-line monitoring and control of liquid-liquid dispersion processes. 17 figures.
Dispersion stability and thermal conductivity of propylene glycol-based nanofluids
Palabiyik, Ibrahim; Witharana, Sanjeeva; Ding, Yulong; 10.1007/s11051-011-0485-x
2012-01-01T23:59:59.000Z
The dispersion stability and thermal conductivity of propylene glycol based nanofluids containing Al2O3 and TiO2 nanoparticles were studied in the temperature range of 20 to 80 {\\deg}C. Nanofluids with different concentrations of nanoparticles were formulated by the two-step method without use of dispersants. In contrast to the common belief the average particle size of nanofluids was observed to decrease with increasing temperature. The nanofluids showed excellent stability over the temperature range of interest. Thermal conductivity enhancement for both of studied nanofluids was a non-linear function of concentration while was temperature independent. Theoretical analyses were performed using existing models and comparisons were made with experimental results. The model based on the aggregation theory appears to yield the best fit. Keywords: Nanofluids, Propylene glycol, Alumina nanoparticles, Titania nanoparticles, Thermal conductivity, Dispersion stability.
Dispersion stability and thermal conductivity of propylene glycol-based nanofluids
Ibrahim Palabiyik; Zenfira Musina; Sanjeeva Witharana; Yulong Ding
2012-05-09T23:59:59.000Z
The dispersion stability and thermal conductivity of propylene glycol based nanofluids containing Al2O3 and TiO2 nanoparticles were studied in the temperature range of 20 to 80 {\\deg}C. Nanofluids with different concentrations of nanoparticles were formulated by the two-step method without use of dispersants. In contrast to the common belief the average particle size of nanofluids was observed to decrease with increasing temperature. The nanofluids showed excellent stability over the temperature range of interest. Thermal conductivity enhancement for both of studied nanofluids was a non-linear function of concentration while was temperature independent. Theoretical analyses were performed using existing models and comparisons were made with experimental results. The model based on the aggregation theory appears to yield the best fit. Keywords: Nanofluids, Propylene glycol, Alumina nanoparticles, Titania nanoparticles, Thermal conductivity, Dispersion stability.
Buckholtz, H.T.; Biermann, A.H.
1980-01-01T23:59:59.000Z
A computational model to simulate the dispersion and coagulation of aerosols emitted from coal-fired power plants was constructed. In modeling the dispersion of the aerosol, turbulent diffusion and wind-driven advection are treated by a finite-difference method. Molecular coagulation is incorporated in the model to follow shifts in the particle-size distribution. Particulate coagulation is mathematically described by Timiskii's equation. The relevent semi-empirical work of Smirnov is incorporated in the model to provide for the coagultion constant. Input for the model is a bimodal, particle-size distribution measured at an operating coal-fired power plant. Simulations indicate that dispersion competes against coagulation mechanisms to maintain the bimodal shaped distribution for 32 km. Turbulence and particle settling tend to enchance coagulation effects. The size-dependent spatial segregation of particles within the plume is predicted.
Charmonium spectra and dispersion relation with improved Bayesian analysis in lattice QCD
A. Ikeda; M. Asakawa; M. Kitazawa
2014-12-01T23:59:59.000Z
We study the charmonium spectral functions at finite momentum and the dispersion relation of $\\eta_c$ at finite temperature. For the analysis of the spectral function, we use an extended maximum entropy method (MEM). We perform the MEM analysis for the product space of Euclidean correlators in different channels or momenta to incorporate information encoded in correlations among the Euclidean correlators in MEM. We find that this method can improve the error of the reconstructed spectral images. To study the dispersion relation, we introduce a definition of the peak position in the spectral image in which the associated error can be estimated on the basis of MEM. We find that the dispersion relation of $\\eta_c$ at finite temperature follows the Lorentz invariant form even near the dissociation temperature $T\\simeq1.7T_c$.
Dispersive Quantum Systems: a class of isolated non-time reversal quantum systems
Lúcio Fassarella
2011-09-02T23:59:59.000Z
A "dispersive quantum system" is a quantum system which is both isolated and non-time reversal invariant. This article presents precise definitions for those concepts and also a characterization of dispersive quantum systems within the class of completely positive Markovian quantum systems in finite dimension (through a homogeneous linear equation for the non-Hamiltonian part of the system's Liouvillian). To set the framework, the basic features of quantum mechanics are reviewed focusing on time evolution and also on the theory of completely positive Markovian quantum systems, including Kossakowski-Lindblad's standard form for Liouvillians. After those general considerations, I present a simple example of dispersive two-level quantum system and apply that to describe neutrino oscillation.
Flow and axial dispersion in a sinusoidal-walled tube: Effects of inertial and unsteady flows
Richmond, Marshall C.; Perkins, William A.; Scheibe, Timothy D.; Lambert, Adam; Wood, Brian D.
2013-12-01T23:59:59.000Z
Dispersion in porous media flows has been the subject of much experimental, theoretical and numerical study. Here we consider a wavy-walled tube (a three-dimensional tube with sinusoidally-varying diameter) as a simplified conceptualization of flow in porous media, where constrictions represent pore throats and expansions pore bodies. A theoretical model for effective (macroscopic) longitudinal dispersion in this system has been developed by volume averaging the microscale velocity field. Direct numerical simulation using computational fluid dynamics (CFD) methods was used to compute velocity fields by solving the Navier-Stokes equations, and also to numerically solve the volume averaging closure problem, for a range of Reynolds numbers (Re) spanning the low-Re to inertial flow regimes, including one simulation at Re = 449 for which unsteady flow was observed. Dispersion values were computed using both the volume averaging solution and a random walk particle tracking method, and results of the two methods were shown to be consistent. Our results are compared to experimental measurements of dispersion in porous media and to previous theoretical results for the low-Re, Stokes flow regime. In the steady inertial regime we observe an power-law increase in effective longitudinal dispersion (DL) with Re, consistent with previous results. This rapid rate of increase is caused by trapping of solute in expansions due to flow separation (eddies). For the unsteady case (Re = 449), the rate of increase of DL with Re was smaller than that observed at lower Re. Velocity fluctuations in this regime lead to increased rates of solute mass transfer between the core flow and separated flow regions, thus diminishing the amount of tailing caused by solute trapping in eddies and thereby reducing longitudinal dispersion.
Construction of the eta->3pi (and K->3pi) amplitudes using dispersive approach
M. Zdrahal; K. Kampf; M. Knecht; J. Novotny
2009-10-09T23:59:59.000Z
The dispersive approach based only on very general principles, unitarity, analyticity and crossing symmetry, combined with chiral counting enables to construct fully relativistic model-independent representations of the eta and K three-pion decays valid up to and including two-loop corrections. Here we demonstrate the procedure on the eta->3pi^0 decay. We perform possible matchings of our dispersive approach with the two-loop ChPT result and briefly discuss corresponding predictions of the Dalitz plot slope parameter alpha.
Observation of spin-wave dispersion in Nd-Fe-B magnets using neutron Brillouin scattering
Ono, K., E-mail: kanta.ono@kek.jp; Inami, N.; Saito, K.; Takeichi, Y.; Kawana, D.; Yokoo, T.; Itoh, S. [Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan); Yano, M.; Shoji, T.; Manabe, A.; Kato, A. [Toyota Motor Corporation, Toyota, Aichi 471-8571 (Japan); Kaneko, Y. [Toyota Central R and D Labs. Inc., Aichi 480-1192 (Japan)
2014-05-07T23:59:59.000Z
The low-energy spin-wave dispersion in polycrystalline Nd-Fe-B magnets was observed using neutron Brillouin scattering (NBS). Low-energy spin-wave excitations for the lowest acoustic spin-wave mode were clearly observed. From the spin-wave dispersion, we were able to determine the spin-wave stiffness constant D{sub sw} (100.0?±?4.9?meV.Å{sup 2}) and the exchange stiffness constant A (6.6 ± 0.3 pJ/m)
McDonald, Thomas Joseph
1982-01-01T23:59:59.000Z
THE EFFECT OF CHEMICAL DISPERSANTS ON THE SOLUTION OF VOLATILE LIQUID HYDROCARBONS FROM SPILLED CRUDE OIL A Thesis by THOMAS JOSEPH McDONALD Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement... for the degree of MASTER OF SCIENCE August 1982 Major Subject: Oceanography THE EFFECT OF CHEMICAL DISPERSANTS ON THE SOLUTION OF VOLATILE LIQUID HYDROCARBONS FROM SPILLED CRUDE OIL A Thesis by THOMAS JOSEPH McDONALD Approved as to style and content by...
Little, Stafford Dean
1991-01-01T23:59:59.000Z
Dispersion Strengthened Aluminum-Iron-Vanadium-Silicon Alloy. (December 1991) Stafford Dean Little, B. S. , Texas A&M University Co-Chairs of Advisory Committee: Dr. M. N. Srinivasan Dr. A. Wolfenden A research program has been completed at Texas A...&M University in which the structure and properties of a rapidly solidified dispersion strengthened aluminum-iron- vanadium-silicon alloy were evaluated. A series of melt spun ribbons of FVS1212 (Fe- 11. 5%, V-1. 4%, Si-2. 2%, Al-bal) were produced...
McDonald, Thomas Joseph
1982-01-01T23:59:59.000Z
THE EFFECT OF CHEMICAL DISPERSANTS ON THE SOLUTION OF VOLATILE LIQUID HYDROCARBONS FROM SPILLED CRUDE OIL A Thesis by THOMAS JOSEPH McDONALD Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement... for the degree of MASTER OF SCIENCE August 1982 Major Subject: Oceanography THE EFFECT OF CHEMICAL DISPERSANTS ON THE SOLUTION OF VOLATILE LIQUID HYDROCARBONS FROM SPILLED CRUDE OIL A Thesis by THOMAS JOSEPH McDONALD Approved as to style and content by...
Dispersion relation approach to sub-barrier heavy-ion fusion reactions
Franzin, V.L.M.; Hussein, M.S.
1988-11-01T23:59:59.000Z
We discuss the conditions under which the dispersion relation technique, extensively employed in the context of elastic scattering, can be used in the analysis of heavy-ion fusion reactions. General unitarity defect arguments are used for this purpose. With the aid of an inverse dispersion relation, which gives the imaginary part of the fusion inclusive polarization potential in terms of the principal part integral involving the real part of the inclusive polarization potential, the sub-barrier fusion of heavy ions is discussed. The system /sup 16/O+/sup A/Sm is taken as an example.
Atmospheric-dispersion index for prescribed burning. Forest Service research paper
Lavdas, L.G.
1986-11-14T23:59:59.000Z
A numerical index that estimates the atmosphere's capacity to disperse smoke from prescribed burning is described. The physical assumptions and mathematical development of the index are described in detail. The index is expressed as a positive integer in such a way that doubling the index implies a doubling of the estimated atmospheric capacity. The dispersion index is conceptually similar to ventilation factor but is better able to describe diurnal changes within the lower atmosphere. The index provides a guide to the effect of prescribed burning activity on atmospheric smoke concentration during a portion of a day.
MnO spin-wave dispersion curves from neutron powder diffraction
Goodwin, Andrew L.; Dove, Martin T. [Department of Earth Sciences, Cambridge University, Downing Street, Cambridge CB2 3EQ (United Kingdom); Tucker, Matthew G. [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Keen, David A. [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Department of Physics, Oxford University, Clarendon Laboratory, Parks Road, Oxford OX1 3PU (United Kingdom)
2007-02-15T23:59:59.000Z
We describe a model-independent approach for the extraction of spin-wave dispersion curves from powder neutron total scattering data. Our approach is based on a statistical analysis of real-space spin configurations to calculate spin-dynamical quantities. The RMCPROFILE implementation of the reverse Monte Carlo refinement process is used to generate a large ensemble of supercell spin configurations from MnO powder diffraction data collected at 100 K. Our analysis of these configurations gives spin-wave dispersion curves for MnO that agree well with those determined independently using neutron triple-axis spectroscopic techniques.
THz-radiation production using dispersively-selected flat electron bunches
Thangaraj, Jayakar
2013-01-01T23:59:59.000Z
We propose an alternative scheme for a tunable THz radiation source generated by relativistic electron bunches. This technique relies on the combination of dispersive selection and flat electron bunch. The dispersive selection uses a slit mask inside a bunch compressor to transform the energy-chirped electron beam into a bunch train. The flat beam transformation boosts the frequency range of the THz source by reducing the beam emittance in one plane. This technique generates narrow-band THz radiation with a tuning range between 0.2 - 4 THz. Single frequency THz spectrum can also be generated by properly choosing the slit spacing, slit width, and the energy chirp.
Mass dispersion in transfer reactions with a stochastic mean-field theory
Kouhei Washiyama; Sakir Ayik; Denis Lacroix
2009-06-24T23:59:59.000Z
Nucleon transfer in symmetric heavy-ion reactions at energies below the Coulomb barrier is investigated in the framework of a microscopic stochastic mean-field theory. While mean-field alone is known to significantly underpredict the dispersion of the fragment mass distribution, a considerable enhancement of the dispersion is obtained in the stochastic mean-field theory. The variance of the fragment mass distribution deduced from the stochastic theory scales with the number of exchanged nucleon. Therefore, the new approach provides the first fully microscopic theory consistent with the phenomenological analysis of the experimental data.
NO HEAVY-ELEMENT DISPERSION IN THE GLOBULAR CLUSTER M92
Cohen, Judith G., E-mail: jlc@astro.caltech.edu [Palomar Observatory, Mail Stop 249-17, California Institute of Technology, Pasadena, CA 91125 (United States)
2011-10-20T23:59:59.000Z
Although there have been recent claims that there is a large dispersion in the abundances of the heavy neutron capture elements in the old Galactic globular cluster M92, we show that the measured dispersion for the absolute abundances of four of the rare earth elements within a sample of 12 luminous red giants in M92 ({<=}0.07 dex) does not exceed the relevant sources of uncertainty. As expected from previous studies, the heavy elements show the signature of the r-process. Their abundance ratios are essentially identical to those of M30, another nearby globular cluster of similar metallicity.
Array of aligned and dispersed carbon nanotubes and method of producing the array
Ivanov, Ilia N; Simpson, John T; Hendricks, Troy R
2013-06-11T23:59:59.000Z
An array of aligned and dispersed carbon nanotubes includes an elongate drawn body including a plurality of channels extending therethrough from a first end to a second end of the body, where the channels have a number density of at least about 100,000 channels/mm.sup.2 over a transverse cross-section of the body. A plurality of carbon nanotubes are disposed in each channel, and the carbon nanotubes are sufficiently dispersed and aligned along a length of the channels for the array to comprise an average resistivity per channel of about 9700 .OMEGA.m or less.
Dispersed Phase of Non-Isothermal Particles in Rotating Turbulent Flows
Pandya, R V R
2015-01-01T23:59:59.000Z
We suggest certain effects, caused by interaction between rotation and gravitation with turbulence structure, for the cooling/heating of dispersed phase of non-isothermal particles in rotating turbulent fluid flows. These effects are obtained through the derivation of kinetic or probability density function based macroscopic equations for the particles. In doing so, for one-way temperature coupling, we also show that homogeneous, isotropic non-isothermal fluid turbulence does not influence the mean temperature (though it influences mean velocity) of the dispersed phase of particles settling due to gravitational force in the isotropic turbulence.
Fang, D.; Yang, L. [Tsinghua Univ., Beijing (China); Sun, C.Z. [Suhou Nuclear Research Inst., Suzhou (China)
1995-01-01T23:59:59.000Z
The relationship between the consequences of the normal exhaust of radioactive materials in air from nuclear power plants and atmospheric dispersion is studied. Because the source terms of the exhaust from a nuclear power plant are relatively low and their radiological consequences are far less than the corresponding authoritative limits, the atmospheric dispersion models, their various modifications, and selections of relevant parameters have few effects on those consequences. In the environmental assessment and siting, the emphasis should not be placed on the consequence evaluation of routine exhaust of nuclear power plants, and the calculation of consequences of the exhaust and atmospheric field measurements should be appropriately, simplified. 12 refs., 5 figs., 7 tabs.
Sumpter, Bobby G [ORNL
2011-01-01T23:59:59.000Z
Polymer nanocomposites (PNCs) are materials based on a class of filled plastics that contain relatively small amounts of nanoparticles, which can impart improved structural, mechanical, and thermal properties relative to the neat polymer. However, the homogeneous dispersion of the nanoparticles into a polymer matrix is critical and an impeding factor for the controlled enhancement of PNC properties. In this work, we provide new insight into the importance of polymer chain connectivity and nanoparticle shape and curvature on the formation of noncovalent electron donor-acceptor (EDA) interactions between polymers and nanoparticles. This is accomplished by experimentally monitoring the dispersion of nanoparticles in copolymers containing varying amounts of functional moieties that can form noncovalent interactions with carbon nanoparticles with corroboration through density functional calculations. The results show that the presence of a minority of interacting functional groups within a polymer chain leads to an optimum interaction between the polymer and fullerene. Density functional theory calculations that identify the binding energy and geometry of the interaction between the functional monomers and fullerenes correspond very well with the experimental results. Moreover, comparison of these results to similar studies with single-walled carbon nanotubes (SWNT) indicate a distinct difference in the ability of EDA interactions to improve the dispersion of fullerenes relative to their impact on SWNT. Thus, the polymer chain connectivity, the polymer chain conformation, and size and shape of the nanoparticle modulate the formation of intermolecular interactions and directly impact the dispersion of the resultant nanocomposite.
Linton, Dias [ORNL; Dadmun, Mark D [ORNL; Sumpter, Bobby G [ORNL; Teh, Say-Lee [ORNL
2011-01-01T23:59:59.000Z
Polymer nanocomposites (PNCs) are materials based on a class of filled plastics that contain relatively small amounts of nanoparticles, which can impart improved structural, mechanical, and thermal properties relative to the neat polymer. However, the homogeneous dispersion of the nanoparticles into a polymer matrix is critical and an impeding factor for the controlled enhancement of PNC properties. In this work, we provide new insight into the importance of polymer chain connectivity and nanoparticle shape and curvature on the formation of noncovalent electron donoracceptor (EDA) interactions between polymers and nanoparticles. This is accomplished by experimentally monitoring the dispersion of nanoparticles in copolymers containing varying amounts of functional moieties that can form noncovalent interactions with carbon nanoparticles with corroboration through density functional calculations. The results show that the presence of a minority of interacting functional groups within a polymer chain leads to an optimum interaction between the polymer and fullerene. Density functional theory calculations that identify the binding energy and geometry of the interaction between the functional monomers and fullerenes correspond very well with the experimental results. Moreover, comparison of these results to similar studies with single-walled carbon nanotubes (SWNT) indicate a distinct difference in the ability of EDA interactions to improve the dispersion of fullerenes relative to their impact on SWNT. Thus, the polymer chain connectivity, the polymer chain conformation, and size and shape of the nanoparticle modulate the formation of intermolecular interactions and directly impact the dispersion of the resultant nanocomposite.