Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Louisiana State University

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 34171 - 34200 of 45178

Full-Text Articles in Entire DC Network

Lower Oceanic Crust Formed At An Ultra-Slow-Spreading Ridge: Ocean Drilling Program Hole 735b, Southwest Indian Ridge, Paul T. Robinson, Henry J.B. Dick, James H. Natland, J. C. Alt, W. Bach, D. Bideau, J. S. Gee, S. Haggis, J. Hertogen, G. Hirth, P. M. Holm, B. Ildefonse, G. J. Iturrino, B. E. John, D. S. Kelley, E. Kikawa, A. Kingdon, P. J. Leroux, J. Maeda, P. S. Meyer, D. J. Miller, H. R. Naslund, Y. L. Niu, J. Snow, R. A. Stephen, P. W. Trimby, H. U. Worm, A. Yoshinobu Jan 2000

Lower Oceanic Crust Formed At An Ultra-Slow-Spreading Ridge: Ocean Drilling Program Hole 735b, Southwest Indian Ridge, Paul T. Robinson, Henry J.B. Dick, James H. Natland, J. C. Alt, W. Bach, D. Bideau, J. S. Gee, S. Haggis, J. Hertogen, G. Hirth, P. M. Holm, B. Ildefonse, G. J. Iturrino, B. E. John, D. S. Kelley, E. Kikawa, A. Kingdon, P. J. Leroux, J. Maeda, P. S. Meyer, D. J. Miller, H. R. Naslund, Y. L. Niu, J. Snow, R. A. Stephen, P. W. Trimby, H. U. Worm, A. Yoshinobu

Faculty Publications

Ocean Drilling Program (ODP) Hole 735B, drilled on Legs 118 and 176, penetrated 1508 m of oceanic layer 3 on a transverse ridge adjacent to the Atlantis II Fracture Zone, Southwest Indian Ridge. The cored sequence consists predominantly of olivine gabbro and troctolite and lesser amounts of gabbro, microgabbro, and gabbronorite rich in Fe-Ti oxides. The section contains five major blocks of relatively primitive olivine gabbro and troctolite, composed of many smaller igneous bodies. Each of these composite blocks shows a small upward decrease in Mg# [defined as 100 × Mg/(Mg + Fe2+)] and contains more fractionated Fe- and Ti-rich …

Go to article

On The Structure Of 3-Connected Matroids And Graphs, James Oxley, Haidong Wu Jan 2000

On The Structure Of 3-Connected Matroids And Graphs, James Oxley, Haidong Wu

Faculty Publications

An element e of a 3-connected matroid M is essential if neither the deletion M\e nor the contraction M/e is 3-connected. Tutte's Wheels and Whirls Theorem proves that the only 3-connected matroids in which every element is essential are the wheels and whirls. In this paper, we consider those 3-connected matroids that have some non-essential elements, showing that every such matroid M must have at least two such elements. We prove that the essential elements of M can be partitioned into classes where two elements are in the same class if M has a fan, a maximal partial wheel, containing …

Go to article

Generalized Δ-Y Exchange And K-Regular Matroids, James Oxley, Charles Semple, Dirk Vertigan Jan 2000

Generalized Δ-Y Exchange And K-Regular Matroids, James Oxley, Charles Semple, Dirk Vertigan

Faculty Publications

This paper introduces a generalization of the matroid operation of Δ-Y exchange. This new operation, segment-cosegment exchange, replaces a coindependent set of k collinear points in a matroid by an independent set of k points that are collinear in the dual of the resulting matroid. The main theorem of the first half of the paper is that, for every field, or indeed partial field, F, the class of matroids representable over F is closed under segment-cosegment exchanges. It follows that, for all prime powers q, the set of excluded minors for GF(q)-representability has at least 2q-4 members. In the second …

Go to article

Exact Relations For Effective Tensors Of Composites: Necessary Conditions And Sufficient Conditions, Yury Grabovsky, Graeme W. Milton, Daniel S. Sage Jan 2000

Exact Relations For Effective Tensors Of Composites: Necessary Conditions And Sufficient Conditions, Yury Grabovsky, Graeme W. Milton, Daniel S. Sage

Faculty Publications

Typically the elastic and electrical properties of composite materials are strongly microstructure dependent. So it comes as a nice surprise to come across exact formulae for effective moduli that are universally valid no matter what the microstructure. Such exact formulae provide useful benchmarks for testing numerical and actual experimental data and for evaluating the merit of various approximation schemes. They can also be regarded as fundamental invariances existing in a given physical context. Classic examples include Hill's formulae for the effective bulk modulus of a two-phase mixture when the phases have equal shear moduli, Levin's formulae linking the effective thermal …

Go to article

Coulomb Gap: How A Metal Film Becomes An Insulator, V. Y.U. Butko, J. F. Ditusa, P. W. Adams Jan 2000

Coulomb Gap: How A Metal Film Becomes An Insulator, V. Y.U. Butko, J. F. Ditusa, P. W. Adams

Faculty Publications

Electron tunneling measurements of the density of states (DOS) in ultrathin Be films reveal that a correlation gap mediates their insulating behavior. In films with sheet resistance Rln(V) Efros-Shklovskii Coulomb gap spectrum finally emerges in the highest R films. Transport measurements of films which display this gap are well described by a universal variable range hopping law R(T) = (h/2e2)exp(T0/T)1/2. © 2000 The American Physical Society.

Go to article

Lower Bounds For Two-Level Additive Schwarz Preconditioners With Small Overlap, Susanne C. Brenner Jan 2000

Lower Bounds For Two-Level Additive Schwarz Preconditioners With Small Overlap, Susanne C. Brenner

Faculty Publications

Lower bounds for the condition numbers of the preconditioned systems are obtained for two-level additive Schwarz preconditioners. They show that the known upper bounds for both second order and fourth order problems are sharp in the case of a small overlap.

Go to article

Front Matter Jan 2000

Front Matter

1650-1850: Ideas, Aesthetics, and Inquiries in the Early Modern Era

No abstract provided.

Go to article

Editor's Choice Underapplauded Books, J. M. Stafford Jan 2000

Editor's Choice Underapplauded Books, J. M. Stafford

1650-1850: Ideas, Aesthetics, and Inquiries in the Early Modern Era

No abstract provided.

Go to article

"Whirlwind Within A Whirlwind" Congreve, Restoration Comedy, And The Play Of History, Will Mcconnell Jan 2000

"Whirlwind Within A Whirlwind" Congreve, Restoration Comedy, And The Play Of History, Will Mcconnell

1650-1850: Ideas, Aesthetics, and Inquiries in the Early Modern Era

No abstract provided.

Go to article

Locke Reading The Law Of Nature Lockeian Hermeneutics And Political Judgment, Andrew Norris Jan 2000

Locke Reading The Law Of Nature Lockeian Hermeneutics And Political Judgment, Andrew Norris

1650-1850: Ideas, Aesthetics, and Inquiries in the Early Modern Era

No abstract provided.

Go to article

Skeptical Ataraxia And Selfhood In Pope's Imitations Of Horace, James Noggle Jan 2000

Skeptical Ataraxia And Selfhood In Pope's Imitations Of Horace, James Noggle

1650-1850: Ideas, Aesthetics, and Inquiries in the Early Modern Era

No abstract provided.

Go to article

Common Life And Animality In Hume, Peter S. Fosl Jan 2000

Common Life And Animality In Hume, Peter S. Fosl

1650-1850: Ideas, Aesthetics, and Inquiries in the Early Modern Era

No abstract provided.

Go to article

Re-Assessing The Classical Tradition Volney's Changing Use Of Artistic Images In Scientific Representations, Michel Huysseune Jan 2000

Re-Assessing The Classical Tradition Volney's Changing Use Of Artistic Images In Scientific Representations, Michel Huysseune

1650-1850: Ideas, Aesthetics, and Inquiries in the Early Modern Era

No abstract provided.

Go to article

Scheherazade's Risk Male Voyeurism And The Female Narrative Gambit, Arthur J. Weitzman Jan 2000

Scheherazade's Risk Male Voyeurism And The Female Narrative Gambit, Arthur J. Weitzman

1650-1850: Ideas, Aesthetics, and Inquiries in the Early Modern Era

No abstract provided.

Go to article

The Royal Captives, A Fragment Of Secret History: Ann Yearsley's "Unnecessary Curiosity", Judith Dorn Jan 2000

The Royal Captives, A Fragment Of Secret History: Ann Yearsley's "Unnecessary Curiosity", Judith Dorn

1650-1850: Ideas, Aesthetics, and Inquiries in the Early Modern Era

No abstract provided.

Go to article

The Poetry Professors Eighteenth-Century Spenserianism And Romantic Concepts Of Culture, David H. Radcliffe Jan 2000

The Poetry Professors Eighteenth-Century Spenserianism And Romantic Concepts Of Culture, David H. Radcliffe

1650-1850: Ideas, Aesthetics, and Inquiries in the Early Modern Era

No abstract provided.

Go to article

Greek Orthodoxy In The Eighteenth Century A Probe, Father John G. Panagiotou Jan 2000

Greek Orthodoxy In The Eighteenth Century A Probe, Father John G. Panagiotou

1650-1850: Ideas, Aesthetics, and Inquiries in the Early Modern Era

No abstract provided.

Go to article

The London Merchant Transmorgrified, Or, Barnwell Unbound John Oxenford's A Day Well Spent (1836), Klaus Stierstorfer Jan 2000

The London Merchant Transmorgrified, Or, Barnwell Unbound John Oxenford's A Day Well Spent (1836), Klaus Stierstorfer

1650-1850: Ideas, Aesthetics, and Inquiries in the Early Modern Era

No abstract provided.

Go to article

Failure As Authority Poetic Voices And The Muse Of Grace In William Cowper's The Task, David Paxman Jan 2000

Failure As Authority Poetic Voices And The Muse Of Grace In William Cowper's The Task, David Paxman

1650-1850: Ideas, Aesthetics, and Inquiries in the Early Modern Era

No abstract provided.

Go to article

Etiquette, Ethics, And Aesthetics, Jennifer Georgia Jan 2000

Etiquette, Ethics, And Aesthetics, Jennifer Georgia

1650-1850: Ideas, Aesthetics, and Inquiries in the Early Modern Era

No abstract provided.

Go to article

Index Jan 2000

Index

1650-1850: Ideas, Aesthetics, and Inquiries in the Early Modern Era

No abstract provided.

Go to article

Captivity Narratives And The Powers Of Horror Eunice Williams And Mary Jemison, Captives Unredeemed, Evelyne Keitel Jan 2000

Captivity Narratives And The Powers Of Horror Eunice Williams And Mary Jemison, Captives Unredeemed, Evelyne Keitel

1650-1850: Ideas, Aesthetics, and Inquiries in the Early Modern Era

No abstract provided.

Go to article

Book Reviews Jan 2000

Book Reviews

1650-1850: Ideas, Aesthetics, and Inquiries in the Early Modern Era

No abstract provided.

Go to article

Gravitational Radiation From Schwarzschild Black Holes: The Second-Order Perturbation Formalism, Reinaldo J. Gleiser, Carlos O. Nicasio, Richard H. Price, Jorge Pullin Jan 2000

Gravitational Radiation From Schwarzschild Black Holes: The Second-Order Perturbation Formalism, Reinaldo J. Gleiser, Carlos O. Nicasio, Richard H. Price, Jorge Pullin

Faculty Publications

The perturbation theory of black holes has been useful recently for providing estimates of gravitational radiation from the black-hole collisions. Second-order perturbation theory, relatively undeveloped until recently, has proved to be important both for providing refined estimates and for indicating the range of validity of perturbation theory. Here we review the second-order formalism for perturbations of Schwarzschild spacetimes. The emphasis is on practical methods for carrying out the second-order computations of the outgoing radiation. General issues are illustrated throughout with examples from "close-limit" results, perturbation calculations in which black holes start from the small separation. © 2000 Elsevier Science B.V.

Go to article

Grazing Collisions Of Black Holes Via The Excision Of Singularities, Steve Brandt, Randall Correll, Roberto Gómez, Mijan Huq, Pablo Laguna, Luis Lehner, Pedro Marronetti, Richard A. Matzner, David Pullin, Jorge Pullin, Erik Schnetter, Deirdre Shoemaker, Jeffrey Winicour Jan 2000

Grazing Collisions Of Black Holes Via The Excision Of Singularities, Steve Brandt, Randall Correll, Roberto Gómez, Mijan Huq, Pablo Laguna, Luis Lehner, Pedro Marronetti, Richard A. Matzner, David Pullin, Jorge Pullin, Erik Schnetter, Deirdre Shoemaker, Jeffrey Winicour

Faculty Publications

We present the first simulations of non-headon (grazing) collisions of binary black holes in which the black hole singularities have been excised from the computational domain. Initially two equal mass black holes m are separated a distance ≈10m and with impact parameter ≈2m. Initial data are based on superposed, boosted (velocity ≈0.5c) solutions of single black holes in Kerr-Schild coordinates. Both rotating and non-rotating black holes are considered. The excised regions containing the singularities are specified by following the dynamics of apparent horizons. Evolutions of up to t≈35m are obtained in which two initially separate apparent horizons are present for …

Go to article

Consistent Canonical Quantization Of General Relativity In The Space Of Vassiliev Invariants, Cayetano Di Bartolo, Rodolfo Gambini, Jorge Griego, Jorge Pullin Jan 2000

Consistent Canonical Quantization Of General Relativity In The Space Of Vassiliev Invariants, Cayetano Di Bartolo, Rodolfo Gambini, Jorge Griego, Jorge Pullin

Faculty Publications

We present a quantization of the Hamiltonian and diffeomorphism constraint of canonical quantum gravity in the spin network representation. The novelty consists in considering a space of wavefunctions based on the Vassiliev knot invariants. The constraints are finite, well defined, and reproduce at the level of quantum commutators the Poisson algebra of constraints of the classical theory. A similar construction can be carried out in 2+1 dimensions leading to the correct quantum theory. © 2000 The American Physical Society.

Go to article

Second Order Perturbations Of A Schwarzschild Black Hole: Inclusion Of Odd Parity Perturbations, Carlos O. Nicasio, Reinaldo Gleiser, Jorge Pullin Jan 2000

Second Order Perturbations Of A Schwarzschild Black Hole: Inclusion Of Odd Parity Perturbations, Carlos O. Nicasio, Reinaldo Gleiser, Jorge Pullin

Faculty Publications

We consider perturbations of a Schwarzschild black hole that can be of both even and odd parity, keeping terms up to second order in perturbation theory, for the 1 = 2 axisymmetric case. We develop explicit formulae for the evolution equations and radiated energies and waveforms using the Regge-Wheeler-Zerilli approach. This formulation is useful, for instance, for the treatment in the "close limit approximation" of the collision of counterrotating black holes. © 2000 Plenum Publishing Corporation.

Go to article

Dynamics Of Diamagnetic Zeeman States Ionized By Half-Cycle Pulses, C. Rangan, K. J. Schafer, A. R.P. Rau Jan 2000

Dynamics Of Diamagnetic Zeeman States Ionized By Half-Cycle Pulses, C. Rangan, K. J. Schafer, A. R.P. Rau

Faculty Publications

We study the dynamical evolution of diamagnetic Zeeman states in hydrogen and sodium atoms ionized by half-cycle pulses. The eigenstates of the combined Coulomb-diamagnetic potential are determined by solving the Schrödinger equation using a grid-based pseudopotential method. We study states with principal quantum number n between [Formula Presented] in the [Formula Presented]-mixing regime at a magnetic field of 6 T. Diamagnetic states that are initially localized parallel and perpendicular to the magnetic field are subjected to the electric field of a half-cycle pulse (HCP) and their time evolution is monitored. We calculate the total ionized fraction, and also the spectrum …

Go to article

Photodetachment In Combined Static And Dynamic Electric Fields, Chitra Rangan, A. P. Rau Jan 2000

Photodetachment In Combined Static And Dynamic Electric Fields, Chitra Rangan, A. P. Rau

Faculty Publications

Through an exact solution of the time-dependent Schrödinger equation for an electron in a static electric field plus the time-dependent electric field of the detaching radiation, the photodetachment cross section of [Formula Presented] is calculated. Careful attention is paid to ensuring proper limiting behavior as the frequency of the time-dependent field goes to zero. We do not find observable effects of a cross term between the two fields on the detachment cross section. Our results point to possible gauge dependence and other difficulties of S-matrix formulations of multiphoton detachment and ionization. © 2000 The American Physical Society.

Go to article

Similarity Analysis Of Nonlinear Equations And Bases Of Finite Wavelength Solitons, A. Ludu, G. Stoitcheva, J. P. Draayer Jan 2000

Similarity Analysis Of Nonlinear Equations And Bases Of Finite Wavelength Solitons, A. Ludu, G. Stoitcheva, J. P. Draayer

Faculty Publications

We introduce a generalized similarity analysis which grants a qualitative description of the localised solutions of any nonlinear differential equation. This procedure provides relations between amplitude, width, and velocity of the solutions, and it is shown to be useful in analysing nonlinear structures like solitons, dublets, triplets, compact supported solitons and other patterns. We also introduce kink-antikink compact solutions for a nonlinear-nonlinear dispersion equation, and we construct a basis of finite wavelength functions having self-similar properties.

Go to article

First Prev Next Last