Physical Sciences and Mathematics Commons^™

The Ising Model On A Dynamically Triangulated Disk With A Boundary Magnetic Field, Simon Catterall, Scott V. Mcguire, Mark Bowick, Simeon Warner

Physics - All Scholarship

We use Monte Carlo simulations to study a dynamically triangulated disk with Ising spins on the vertices and a boundary magnetic field. For the case of zero magnetic field we show that the model possesses three phases. For one of these the boundary length grows linearly with disk area, while the other two phases are characterized by a boundary whose size is on the order of the cut-off. A line of continuous magnetic transitions separates the two small boundary phases. We determine the critical exponents of the continuous magnetic phase transition and relate them to predictions from continuum 2-d quantum …

Effects Of Woody Cover In The Landscaping On Riparian Avifauna And A Preliminary Nesting Assessment, Micah W. Perkins

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.

Movements And Habitat Use By Hatchery-Reared Pallid Sturgeon In The Lower Platte River, Nebraska, Vaughn A. Snook

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.

Announcements: Spring 2001

Drought Network News (1994-2001)

Contents:

IAEM’s 49th Annual Conference and Exhibit

International Conference on Drought Mitigation and Prevention of Land Desertification

New Book

Results Of A Rapid Appraisal Study: Agricultural Producers’ Perceptions Of Drought Vulnerability And Mitigation—Howard County, Nebraska, Cody L. Knutson, Matthew L. Blomstedt, Kara Slaughter

Drought Network News (1994-2001)

Drought is the leading natural disaster in the United States in terms of monetary losses. The National Research Council (1995) estimates that drought costs the United States an average of $6–8 billion per year. Because of these losses and the great effects of drought on many citizens’ quality of life, drought planning is gaining widespread support in the United States. However, U.S. drought planning within the agricultural sector has historically focused on response measures that help producers, primarily farmers, deal with and recover from drought. It has been found that these often ad-hoc drought responses are very expensive and do …

Droughts And Dew Bean Productivity In Northwestern Arid Rajasthan, India, Pratap Narain, R. S. Singh, D. Kumar

Drought Network News (1994-2001)

Arid ecosystems constitute an important part of the world’s dry climates. The Indian arid zone is characterized by a harsh and fragile system, which influences the productivity (both quantitative and qualitative) and socioeconomic status of the inhabitants. The study discussed in this article was conducted in the Bikaner region, which is one of the most drought-prone districts of Rajasthan (Figure 1). Annual rainfall in the district is 268 mm, of which 85% occurs during the southwest summer monsoon (July–September). The region is known to experience extreme variations in diurnal and seasonal temperatures and high wind velocity, particularly during summers, associated …

Winter Drought In Iran: Associations With Enso, M. J. Nazemosadat

Drought Network News (1994-2001)

The Islamic Republic of Iran (Figure 1) has an area of 1,648,000 km² and a population of 65 million people (1995 estimate). The country has arid and semiarid climates and the occurrence of rainfall is unreliable, with a coefficient of variation as high as 70%. The average annual precipitation over the country is around 250 mm. Two mountain ridges, the Alborz and Zagros (Figure 1), which run east and southeast from the northwest corner of the country, play an influential role in determining the amount and spatial distribution of rainfall. The peaks of Alborz and Zagros are about 5,700 …

Time Dependent Density Functional Theory Of Dynamical Response In 3d And 4d Metals, James M. Sullivan

Doctoral Dissertations

Two different but complementary quantum mechanical many-body problems are investigated. These problems include both static and dynamic aspects of the electronelectron interaction in real materials. In Chapter One, we take up the cases of Ag and Ni with a microscopic evaluation of the dielectric function and loss function using the formalism of time dependent density functional theory and all-electron techniques. We address the striking line shapes that have been recently observed via inelastic scattering experiments. The present work reveals three relevant energy scales for excitations in the selected systems. These scales are argued to be generic to a large number …

Error Estimation Of Bathymetric Grid Models Derived From Historic And Contemporary Data Sets, Martin Jakobsson, Brian R. Calder, Larry A. Mayer, Andy Armstrong

Center for Coastal and Ocean Mapping

The past century has seen remarkable advances in technologies associated with positioning and the measurement of depth. Lead lines have given way to single beam echo sounders, which in turn are being replaced by multibeam sonars and other means of remotely and rapidly collecting dense bathymetric datasets. Sextants were replaced by radio navigation, then transit satellite, GPS and now differential GPS. With each new advance comes tremendous improvement in the accuracy and resolution of the data we collect. Given these changes and given the vastness of the ocean areas we must map, the charts we produce are mainly compilations of …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 17, Number 8, May 2001, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

An eight page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Spring/Summer 2001, Nsu Oceanographic Center

Currents

No abstract provided.

Nucleation Of Water And Methanol Droplets On Cations And Anions: The Sign Preference, K.J. Oh, G.T. Gao, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

The barrier height to cation- and anion-induced nucleation to produce water and methanol droplets are calculated by means of an umbrella-sampling Monte Carlo method. The computer simulation corroborates the century-old finding of Wilson that the anion is a better nucleator to produce water droplets than the cation having the same magnitude of charge, even without the presence of external electric field. The simulation also shows that the cation is a better nucleator to produce methanol droplets than the anion.

Geometric Realization And K-Theoretic Decomposition Of C*-Algebras, Claude Schochet

Mathematics Faculty Research Publications

Suppose that A is a separable C*-algebra and that G∗ is a (graded) subgroup of the ℤ/2-graded group K∗(A). Then there is a natural short exact sequence

0 → G∗ → K∗(A) → K∗(A)/G∗ → 0.

In this note we demonstrate how to geometrically realize this sequence at the level of C*-algebras. As a result, we KK-theoretically decompose A as

0 → A ⊗ [cursive]K → A_ƒ → SA_t → 0

where K∗(A_t) is the torsion subgroup of …

Towards Regional Assimilation Of Lagrangian Data: The Lagrangian Form Of The Shallow Water Reduced Gravity Model And Its Inverse, J. L. Mead, A. F. Bennett

Mathematics Faculty Publications and Presentations

Variational data assimilation for Lagrangian geophysical fluid dynamics is introduced. Lagrangian coordinates add numerical difficulties into an already difficult subject, but also offer certain distinct advantages over Eulerian coordinates. First, float position and depth are defined by linear measurement functionals. Second, Lagrangian or ‘comoving’ open domains are conveniently expressed in Lagrangian coordinates. The attraction of such open domains is that they lead to well-posed prediction problems [Bennett and Chua (1999)] and hence efficient inversion algorithms. Eulerian and Lagrangian solutions of the inviscid forward problem in a doubly periodic domain, with North Atlantic mesoscales, are compared and found to be in …

Visualizing Rhizosphere Chemistry Of Legumes With Mid-Infrared Synchrotron Radiation, Ted K. Raab, Michael C. Martin

Ted K. Raab

A bright synchrotron light source operated by the Lawrence Berkeley National Laboratory served as an external source for infrared (IR) microscopy of plant root microcosms. Mid-IR light from synchrotrons is 2-3 orders of magnitude brighter than conventional sources, providing contrast based on the chemical information in the reflected signal at a spatial resolution near the diffraction-limit of 3-10 microns. In an experiment using plant root microcosms fitted with zinc selenide IR-transmissive windows (50 mm x 20 mm x 1 mm), we describe chemical differences and similarities within the root zone of mung bean (Vigna radiata L.), grown with or without …

Simulation Of Inviscid Multi-Species Plasma Flow, Alexandre Martin, Marcelo Reggio, Jean-Yves Trépanier

Alexandre Martin

A multi-species solver for plasma at thermodynamical equilibrium is developed. A numerical scheme, based on Roe's, is implemented with some modification regarding the average quantities. A perfect gas treatment is carried out for validations, and a quasi-real gas treatment is also presented. The latter takes into account the changes in the composition of the gas caused by fluctuations in temperature and density.

Σary, Minnesota State University Moorhead, Mathematics Department

Math Department Newsletters

No abstract provided.

What "Is" Mathematics?: In Memoriam Of Gian-Carlo Rota, Gian-Carlo Rota

Humanistic Mathematics Network Journal

No abstract provided.

Hotel Infinity, Lawrence Mark Lesser

Humanistic Mathematics Network Journal

No abstract provided.

Poetry, Arnold L. Trindade

Humanistic Mathematics Network Journal

No abstract provided.

Naïve Thoughts On The Paradox Of Gödel, Philip J. Davis

Humanistic Mathematics Network Journal

No abstract provided.

A Geometry Course For Prospective Secondary School Teachers, Jeff Connor, Barbara Grover

Humanistic Mathematics Network Journal

No abstract provided.

The Need To Diversify The Ranks Of Teachers Of Mathematics, Frederick L. Uy

Humanistic Mathematics Network Journal

This paper intends to give rationales for the need to diversify the ranks of teachers of mathematics. It also suggests ideas that we can take to alleviate the situation that we currently are confronting.

Announcement: Association For Women In Mathematics Mentor Network

Humanistic Mathematics Network Journal

No abstract provided.

Problems In Which Given Information Is Ignored, Howard Wachtel

Humanistic Mathematics Network Journal

A set of problems is presented and discussed for which there is a tendency for students to ignore part of the given information in the problem and to substitute some extraneous assumptions. Typical student reactions are also discussed.

Educating The Public About School Mathematics, Zalman Usiskin

Humanistic Mathematics Network Journal

No abstract provided.

Zero, Sheila A. Mcneill

Humanistic Mathematics Network Journal

No abstract provided.

Hamilton's Icosian Calculus And His Icosian Game, Katye O. Sowell

Humanistic Mathematics Network Journal

No abstract provided.

Representation, Lawrence Mark Lesser

Humanistic Mathematics Network Journal

No abstract provided.

Book Review: The Teaching Gap By James W. Stigler And James Hiebert, Michael L. Brown

Humanistic Mathematics Network Journal

No abstract provided.