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1997

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Full-Text Articles in Physical Sciences and Mathematics

Preference And Motivation Testing, David Fraser, Lindsay R. Matthews Jan 1997

Preference And Motivation Testing, David Fraser, Lindsay R. Matthews

Validation of Animal Experimentation Collection

Since the early 1970s, scientists have used preference tests (tests that require animals to choose between two or more different options or environments) as a means of answering questions about animal welfare. Preference tests have been used to establish animals' preferences for common housing options such as ambient temperature, illumination and preferred types of bedding and flooring; to improve the effectiveness of devices such as loading ramps and nest boxes; and to clarify how strongly animals avoid various aspects of confinement and methods of restraint.

To use preference research to answer questions about animal welfare, three issues need to be …


Elimination Of Supply Harmonics, Stephen L. Clark, P. Famouri, W. L. Cooley Jan 1997

Elimination Of Supply Harmonics, Stephen L. Clark, P. Famouri, W. L. Cooley

Mathematics and Statistics Faculty Research & Creative Works

The price of the extensive use of power electronic devices is becoming clear: increasing harmonic "pollution." The greater amount of harmonics being introduced into power distribution systems is of concern to both power consumers and power companies. First, a brief look is taken at background information which describes harmonic sources, effects, and characteristics. Then the evolution of the harmonics elimination approaches of current compensation and active filtering are discussed to give some insight into the directions that research is taking.


On The Behavior Of The Solutions Of The Navier-Stokes Equations At Vanishing Viscosity, Roger Temam, Xiaoming Wang Jan 1997

On The Behavior Of The Solutions Of The Navier-Stokes Equations At Vanishing Viscosity, Roger Temam, Xiaoming Wang

Mathematics and Statistics Faculty Research & Creative Works

In this article we establish partial results concerning the convergence of the solutions of the Navier-Stokes equations to that of the Euler equations. Namely, we prove convergence on any finite interval of time, in space dimension two, under a physically reasonable assumption. We consider the flow in a channel or the flow in a general bounded domain.


Time Averaged Energy Dissipation Rate For Shear Driven Flows In ℝⁿ, Xiaoming Wang Jan 1997

Time Averaged Energy Dissipation Rate For Shear Driven Flows In ℝⁿ, Xiaoming Wang

Mathematics and Statistics Faculty Research & Creative Works

We drive an upper bound of the time averaged energy dissipation rate for boundary driven flows directly from the Navier-Stokes equations in ℝn. the upper bound is independent of the kinematic viscosity in accordance with Kolomogorov's scaling result. Copyright © 1997 Elsevier Science B.V. All rights reserved.


Disconjugacy And Transformations For Symplectic Systems, Martin Bohner, Ondřej Došlý Jan 1997

Disconjugacy And Transformations For Symplectic Systems, Martin Bohner, Ondřej Došlý

Mathematics and Statistics Faculty Research & Creative Works

We examine transformations and diconjugacy for general symplectic systems which include as special cases linear Hamiltonian difference systems and Sturm-Liouville difference equations of higher order. We give a Reid roundabout theorem for these systems and also for reciprocal symplectic systems. Particularly, we investigate a connection between eventual disconjugacy of linear Hamiltonian difference systems and their reciprocals. Finally, we present a dinsconjugacy-preserving transformation of a Sturm-Liouville equation of higher order which transforms this equation into another one of the same order.


Sea Turtle Conservation Program, Broward County, Fl 1997 Report, Curtis M. Burney, William E. Margolis Jan 1997

Sea Turtle Conservation Program, Broward County, Fl 1997 Report, Curtis M. Burney, William E. Margolis

Marine & Environmental Sciences Faculty Reports

Since 1978, the Broward County Environmental Protection Department (BCEPD) has provided for the conservation of endangered and threatened sea turtle species within its area of responsibility. Broward County is within the normal nesting areas of three species of sea turtles: the loggerhead sea turtle (Caretta caretta), the green sea turtle (Chelonia mydas) and the leatherback sea turtle (Dermochelys coriacea). The loggerhead is listed as a threatened species, while the green and leatherback are listed as endangered under the U.S. Endangered Species Act, 1973, and Chapter 370, F.S.

Since these statutes strictly forbid any disturbance …


Climate Records In Coral Skeletons, Peter K. Swart, Richard E. Dodge Jan 1997

Climate Records In Coral Skeletons, Peter K. Swart, Richard E. Dodge

Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures

No abstract provided.


Barium Chronologies From South Florida Reef Corals - Environmental Implications, D. Anderegg, Richard E. Dodge, Peter K. Swart, L. Fisher Jan 1997

Barium Chronologies From South Florida Reef Corals - Environmental Implications, D. Anderegg, Richard E. Dodge, Peter K. Swart, L. Fisher

Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures

Benthic algal blooms (e.g., Codium isthmocladum) have become increasingly common on reefs and hardgrounds of Southeast Florida. The contribution from possible responsible nutrient sources, including natural upwelling and local pollution, has not been quantified. In an attempt to differentiate each potential source, lattice-bound barium concentrations in the skeletons of two common Southeast Florida stony coral species (Montastraea faveolata and Solenastrea bournoni) were measured by isotope dilution inductively coupled mass spectrometry (ICP/MS). Specimens were collected offshore between 26˚01'-57'N at shallow (10m) and deep (20m) reefs. X-rays of skeletal slabs revealed annual density bands which guided annual and subannual …


Fall 1997, Nsu Oceanographic Center Jan 1997

Fall 1997, Nsu Oceanographic Center

Currents

No abstract provided.


Spring 1997, Nsu Oceanographic Center Jan 1997

Spring 1997, Nsu Oceanographic Center

Currents

No abstract provided.


Summer 1997, Nsu Oceanographic Center Jan 1997

Summer 1997, Nsu Oceanographic Center

Currents

No abstract provided.


Winter 1997, Nsu Oceanographic Center Jan 1997

Winter 1997, Nsu Oceanographic Center

Currents

No abstract provided.


Sodium Nitrite Alone Protects The Brain O _I_ Microsomal Ca -Atpase Against Potassium Cyanide-Induced Neurotoxicity In Rats, Odutayo O. Odunuge, G.. A. Adenuga Jan 1997

Sodium Nitrite Alone Protects The Brain O _I_ Microsomal Ca -Atpase Against Potassium Cyanide-Induced Neurotoxicity In Rats, Odutayo O. Odunuge, G.. A. Adenuga

Faculty Publications

The effect of a short-term oral administration of potassium cyanide (KCN) (200 ppm in diet) with or without sodium nitrite (NaNO2) pretreatment on rat brain microsomal Ca2* ATPase was investigated. The specific activity value of the enzyme significantly decreased (p<0.05) by 50% compared with control and by 63% for KCN-treated rats compared with KCN-treated rats pretreated with NaNO;,. There was no significant difference at the h = 0.05 level between the values obtained for the control and KCN-treated rats pretreated with NaNO,. These results show both that feeding lowers brain microsomal Ca2f-ATPase activity and that NaNO, has a protective role (antidote function) in that respect.


Electron-Impact Ionization Cross Sections Of Atmospheric Molecules, Y.-K. Kim, W. Hwang, N. M. Weinberger, M. A. Ali, M. Eugene Rudd Jan 1997

Electron-Impact Ionization Cross Sections Of Atmospheric Molecules, Y.-K. Kim, W. Hwang, N. M. Weinberger, M. A. Ali, M. Eugene Rudd

M. Eugene Rudd Publications

A theoretical model for electron-impact total ionization cross sections, which has been found to be reliable for a wide range of molecules, is applied to molecules of interest to atmospheric science. The new theory, the binary-encounter-Bethe (BEB) model, combines the binary encounter theory and the Bethe theory for electron-impact ionization, and uses simple theoretical data for the ground state of the target molecule, which are readily available from molecular structure codes. Total ionization cross sections of 11 molecules, CS, CS2, COS, CH4, H2S, NH3, NO2, N2O, O3 …


Electron-Impact Total Ionization Cross Sections Of Silicon And Germanium Hydrides, M. A. Ali, Y.-K. Kim, W. Hwang, N. M. Weinberger, M. Eugene Rudd Jan 1997

Electron-Impact Total Ionization Cross Sections Of Silicon And Germanium Hydrides, M. A. Ali, Y.-K. Kim, W. Hwang, N. M. Weinberger, M. Eugene Rudd

M. Eugene Rudd Publications

Electron-impact total ionization cross sections of some silicon and germanium compounds have been calculated by applying a new theoretical model that has been found to be reliable for a wide range of molecules. The new theory, the binary-encounter-Bethe (BEB) model, combines the binary-encounter theory and the Bethe theory for electron-impact ionization, and uses simple theoretical molecular orbital data—binding energies, average kinetic energies, and occupation numbers—which are readily available from molecular structure codes. Total ionization cross sections of SiH, SiH2, SiH3, SiH4, Si2H6, Si(CH3)4, GeH, GeH2 …


Radial Dose Model Of Ssb, Dsb, Deletions And Comparisons To Montecarlo Track Structure Simulations, Francis A. Cucinotta, H. Nikjoo, J. W. Wilson, Robert Katz, D. T. Goodhead Jan 1997

Radial Dose Model Of Ssb, Dsb, Deletions And Comparisons To Montecarlo Track Structure Simulations, Francis A. Cucinotta, H. Nikjoo, J. W. Wilson, Robert Katz, D. T. Goodhead

Robert Katz Publications

The initial lesions formed in DNA by ionizing radiation include base damage, single strand breaks (SSB), double strand breaks (DSB), DNA cross links, and deletions. Deletions occur through energy deposition and perhaps more importantly through recombination repair of DSB's. Several mechanisms for the formation of DSB's and deletions related to energy deposition can be considered. Track simulation codes have indicated the importance of clusters of ionizations in small volumes similar to the size of a nucleosome. These clusters have been related to several types of damage to DNA, including DSB and deletions resulting from multiple DSB's formed by single electron …


Restoration Of An Urban Salt Marsh: An Interdisciplinary Approach, David G. Casagrande Jan 1997

Restoration Of An Urban Salt Marsh: An Interdisciplinary Approach, David G. Casagrande

Yale School of the Environment Bulletin Series

No abstract provided.


Bridges To Sustainability: Business And Government Working Together For A Better Environment, Luis Gomez-Echeverri Jan 1997

Bridges To Sustainability: Business And Government Working Together For A Better Environment, Luis Gomez-Echeverri

Yale School of the Environment Bulletin Series

No abstract provided.


Eastern South Dakota Wetlands, Rex R. Johnson, Kenneth F. Higgins, Michael L. Kjellsen, Charles R. Elliot Jan 1997

Eastern South Dakota Wetlands, Rex R. Johnson, Kenneth F. Higgins, Michael L. Kjellsen, Charles R. Elliot

Natural Resource Management Faculty Books

Diverse and extensive wetland resources have always been familiar parts of the landscape to farmers, hunters, and residents of eastern South Dakota. The journals and oral histories of adventurers, trappers, and natives and immigrants reveal how wetlands shaped the wildlife and the people who lived on and modified the land to meet their own needs. The history of South Dakota wetlands parallels the history and interactions of people and wetlands elsewhere in North America and the world. This interaction can best be characterized as constant conflict. Driven primarily by economics, farmers the world over expended tremendous energy to "reclaim" and …


Wetland Resources Of Eastern South Dakota, Rex R. Johnson, Kenneth F. Higgins Jan 1997

Wetland Resources Of Eastern South Dakota, Rex R. Johnson, Kenneth F. Higgins

Natural Resource Management Faculty Books

The mere mention of the word "wetland" in coffee shops and other gathering places on the prairies today brings out emotions and opinions that run the gamut from saving them all to draining them all. To some people, what we do with wetlands has been, and still is, a personal choice, a matter of exercising individual rights on private property. To others, wetlands are community resources that provide values that touch all of society. They contend that what is done to and about wetlands is a community decision regardless of ownership. Herein lies the controversy we have experienced over wetlands …


Combinatorics Of Open Covers (Iii): Games, CP(X), Marion Scheepers Jan 1997

Combinatorics Of Open Covers (Iii): Games, CP(X), Marion Scheepers

Mathematics Faculty Publications and Presentations

Some of the covering properties of spaces as defined in Parts I and II are here characterized by games. These results, applied to function spaces Cp(X) of countable tightness, give new characterizations of countable fan tightness and countable strong fan tightness. In particular, each of these properties is characterized by a Ramseyan theorem.


A Feedback Control Structure For On-Line Learning Tasks, Manfred Huber, Roderic Grupen Jan 1997

A Feedback Control Structure For On-Line Learning Tasks, Manfred Huber, Roderic Grupen

Roderic Grupen

This paper addresses adaptive control architectures for systems that respond autonomously to changing tasks. Such systems often have many sensory and motor alternatives and behavior drawn from these produces varying quality solutions. The objective is then to ground behavior in control laws which, combined with resources, enumerate closed-loop behavioral alternatives. Use of such controllers leads to analyzable and predictable composite system, permitting the construction of abstract behavioral models. Here, discrete event system and reinforcement learning techniques are employed to constrain the behavioral alternatives and to synthesize behavior on-line. To illustrate this, a quadruped


Learning To Coordinate Controllers -- Reinforcement Learning On A Control Basis, Manfred Huber, Roderic Grupen Jan 1997

Learning To Coordinate Controllers -- Reinforcement Learning On A Control Basis, Manfred Huber, Roderic Grupen

Roderic Grupen

Autonomous robot systems operating in an uncertain environment have to be reactive and adaptive in order to cope with changing environment conditions and task requirements. To achieve this, the hybrid control architecture presented in this paper uses reinforcement learning on top of a Discrete Event Dynamic System (DEDS) framework to learn to supervise a set of basis controllers in order to achieve a given task. The use of an abstract system model in the automatically derived supervisor reduces the complexity of the learning problem. In addition, safety constraints may be imposed a priori, such that the system learns on-line in …


Numerical Solution Of The Eigenvalue Problem For Hermitian Toeplitz Matrices, William Trench, Michael Ng Jan 1997

Numerical Solution Of The Eigenvalue Problem For Hermitian Toeplitz Matrices, William Trench, Michael Ng

William F. Trench

No abstract provided.


Nmr And Vortex Lattice Melting In Yba2cu3o7, Charles Recchia, J Martindale, C Pennington, W Hults, J Smith Jan 1997

Nmr And Vortex Lattice Melting In Yba2cu3o7, Charles Recchia, J Martindale, C Pennington, W Hults, J Smith

Charles H Recchia

No abstract provided.


The Brain As A Symbol-Processing Machine., Armando F. Rocha Jan 1997

The Brain As A Symbol-Processing Machine., Armando F. Rocha

Armando F Rocha

The knowledge accumulated about the biochemistry of the synapsis in the last decades completely changes the notion of brain processing founded exclusively over an electrical mechanism, toward that supported by a complex chemical message exchange occurring both locally, at the synaptic site, as well as at other localities, depending on the solubility of the involved chemical substances in the extracellular compartment. These biochemical transactions support a rich symbolic processing of the information both encoded by the genes and provided by actual data collected from the surrounding environment, by means of either special molecular or cellular receptor systems. In this processing, …


An Augmented Galerkin Method For Singular Integral Equations With Hilbert Kernel, S. Abbasbandy, E. Babolian Jan 1997

An Augmented Galerkin Method For Singular Integral Equations With Hilbert Kernel, S. Abbasbandy, E. Babolian

Saeid Abbasbandy

In recent papers, Delves [2] and others [1], [3] described a Chebyshev series method for the numerical solution of integral equations with non-singular kernels or some particular singular kernels, for example Green's function kernel, logarithmic and Cauchy kernels and so on. In this paper we describe a Fourier series expansion method for a class of singular integral equations with Hilbert kernel and constant coefficients. We give a number of numerical examples showing that Galerkin method works well in practice.


Local Nonequilibrium Transport Models, Sergey Sobolev Jan 1997

Local Nonequilibrium Transport Models, Sergey Sobolev

Sergey Sobolev

No abstract provided.


Local Non-Equilibrium Diffusion Effects On The Kinetic Phase Boundaries In Solidification, Sergey Sobolev Jan 1997

Local Non-Equilibrium Diffusion Effects On The Kinetic Phase Boundaries In Solidification, Sergey Sobolev

Sergey Sobolev

No abstract provided.


Pseudo-Steady States In The Model Of The Bray-Liebhafsky Oscillatory Reaction, Zeljko D. Cupic Jan 1997

Pseudo-Steady States In The Model Of The Bray-Liebhafsky Oscillatory Reaction, Zeljko D. Cupic

Zeljko D Cupic

No abstract provided.