Physical Sciences and Mathematics Commons^™

Problems To Discover And To Boost Mathematical Talent In Early Grades: A Challenging Situations Approach, Viktor Freiman

The Mathematics Enthusiast

Several studies of mathematical giftedness conducted in the past two decades reveal the importance of creation of learning and teaching environment favourable to the identification and nurturing mathematically talented students. Based on psychological, methodological and didactical models created by Krutetskii (1976), Shchedrovtiskii (1968), Brousseau (1997) and Sierpinska (1994), we have developed our challenging situation approach. During 7 years of field study in the elementary K-6 classroom, we collected sufficient amount of data that demonstrate how these challenging situations help to discover and to boost mathematical talent in very young children keeping and increasing their interest towards more advanced mathematics curriculum. …

Building Blocks Problem Related To Harmonic Series, Yutaka Nishiyama

The Mathematics Enthusiast

In this discussion I give an explanation of the divergence and convergence of infinite series through the building blocks problem and at the same time I touch on the fact that mathematics is not just about manipulating complicated numerical formulas but also a field in which logical ways of thought are learnt. I emphasize that in order to overcome the aversion of university students to mathematics, teachers must pour their energies into developing study materials taken from topics relevant to the students.

Modeling Interdisciplinary Activities Involving Mathematics And Philosophy, Steffen M. Iversen

The Mathematics Enthusiast

In this paper a didactical model is presented. The goal of the model is to work as a didactical tool, or conceptual frame, for developing, carrying through and evaluating interdisciplinary activities involving the subject of mathematics and philosophy in the high schools. Through the terms of Horizontal Intertwining, Vertical Structuring and Horizontal Propagation the model consists of three phases, each considering different aspects of the nature of interdisciplinary activities. The theoretical modelling is inspired by work which focuses on the students abilities to concept formation in expanded domains (Michelsen, 2001, 2005a, 2005b). Furthermore the theoretical description rest on a series …

Fisheries Research Report No. 153 - A 12-Month Survey Of Recreational Fishing In The Pilbara Region Of Western Australia During 1999-2000, P C. Williamson, Neil R. Sumner, B E. Malseed

Fisheries research reports

A 12-month creel survey of recreational boat-based and shore-based fishing in the Pilbara region (Onslow to Broome inclusive) of Western Australia was conducted between December 1999 and November 2000. During the survey 3,085 boat crews were interviewed at public boat ramps when they returned from their fishing trips. Patrols conducted along the coastline interviewed 73 groups of boat-based fishers and 569 groups of shore-based fishers at fishing locations and camp sites.

The total annual recreational fishing effort for the Pilbara region was estimated to be 201,000 fisher days (95%CI: 193,000 – 210,000). This comprised 109,000 fisher days by boats launched …

A C-Symplectic Free S1-Manifold With Contractible Orbits And Cat = 1/2 Dim, Christopher Allday, John Oprea

Mathematics and Statistics Faculty Publications

An interesting question in symplectic geometry concerns whether or not a closed symplectic manifold can have a free symplectic circle action with orbits contractible in the manifold. Here we present a c-symplectic example, thus showing that the problem is truly geometric as opposed to topological. Furthermore, we see that our example is the only known example of a c-symplectic manifold having non-trivial fundamental group and Lusternik-Schnirelmann category precisely half its dimension.

Allocating Non-Real-Time And Soft Real-Time Jobs In Multiclusters, Ligang He, Stephen A. Jarvis, Daniel P. Spooner, Hong Jiang, Donna N. Dillenberger, Graham R. Nudd

School of Computing: Faculty Publications

This paper addresses workload allocation techniques for two types of sequential jobs that might be found in multicluster systems, namely, non-real-time jobs and soft real-time jobs. Two workload allocation strategies, the Optimized mean Response Time (ORT) and the Optimized mean Miss Rate (OMR), are developed by establishing and numerically solving two optimization equation sets. The ORT strategy achieves an optimized mean response time for non-real-time jobs, while the OMR strategy obtains an optimized mean miss rate for soft real-time jobs over multiple clusters. Both strategies take into account average system behaviors (such as the mean arrival rate of jobs) in …

Interpretational Difficulties In Quantum Field Theory, P Krekora, Q Su, Rainer Grobe

Faculty publications – Physics

Based on space-time-resolved solutions to relativistic quantum field theory we illustrate interpretational difficulties in associating field-theoretical quantities with properties of particles. These difficulties are related to the fact that the definition of the spatial probability density of particles depends on the choice of the Hilbert subspace on which the field operator is projected. We illustrate these problems by analyzing pair-production probabilities and spatial densities for the electron-positron dynamics associated with a spatially localized subcritical potential that is turned on and off in time.

Precise Radial Velocities Of Giant Stars. I. Stable Stars, S. Hekker, S. Reffert, A. Quirrenbach, D. S. Mitchell, D. A. Fischer, G. W. Marcy, R. P. Butler

Physics

Context. Future astrometric missions such as SIM PlanetQuest need very stable reference stars. K giants have large luminosities, which place them at large distances and thus the jitter of their photocenters by companions is relatively small. Therefore K giants would be best suited as references. To confirm this observationally a radial velocity survey is performed to quantify the level of intrinsic variability in K giants.

Aims. From this radial velocity survey we present 34 K giants with an observed standard deviation of the radial velocity of less than 20 m/s. These stars are considered “stable” and can be used as …

Size And Properties Of The Nlr In The Seyfert-2 Galaxy Ngc1386, N. Bennert, B. Jungwiert, S. Komossa

Physics

We study the narrow-line region (NLR) of the Seyfert-2 galaxy NGC 1386 by means of long-slit spectroscopy obtained with FORS1 at the VLT. We use the galaxy itself for subtracting the stellar template, applying reddening corrections to fit the stellar template to the spectra of the NLR. The continuum gets steadily redder towards the nucleus. The spatial distribution of the reddening derived from the Balmer decrement differs from the continuum reddening, indicating dust within the NLR with a varying column density along the line of sight. Using spatially resolved spectral diagnostics, we find a transition between central line ratios falling …

(±)-1-Methyl-1,3,6-Triphenyl-7-(2-Phenylpropenyl)-1, 2-Dihydronaphthalene, Yongqiang Sui, Charles Leslie Barnes, Rainer Glaser

Chemistry Faculty Research & Creative Works

The crystal structure of the title compound, C₃₈H₃₂, presents a novel framework that combines the functionalities of a 1,6-diarene-substituted 1,2-dihydronaphthalene (DHN) with a 1,4-distyrylbenzene (DSB) to form a crossed bis-diarene. The lamellar crystal structure is held together by arene-arene interactions. While the orientations of the phenyl rings of the DSB units alternate within both the R and the S substructures, the homochiral substructures feature opposing polarity along the long axes of the DHN-based diarenes.

Black Hole Particle Emission In Higher-Dimensional Spacetimes, Vitor Cardoso, Marco Cavaglia, Leonardo Gualtieri

Physics Faculty Research & Creative Works

In models with extra dimensions, a black hole evaporates both in the bulk and on the visible brane, where standard model fields live. The exact emissivities of each particle species are needed to determine how the black hole decay proceeds. We compute and discuss the absorption cross sections, the relative emissivities, and the total power output of all known fields in the evaporation phase. Graviton emissivity is highly enhanced as the spacetime dimensionality increases. Therefore, a black hole loses a significant fraction of its mass in the bulk. This result has important consequences for the phenomenology of black holes in …

Zion National Park Environment Assessment/ Assessment Of Effect, Engineering-Environmental Management, Inc.

Elusive Documents

This environmental assessment I assessment of effect examines in detail two alternatives: no action and the National Park Service preferred alternative. The preferred alternative considers rehabilitation of the roadway and associated structures on either side of Route 10 (Zion-Mt. Carmel Highway) tunnel. The road work would primarily occur on the east side of the tunnel in a 0.25-mile segment beginning at the east tunnel entrance. Modifications on the east side of the tunnel would include slurry sealing the road surface and scaling rock slopes on both sides of the road; re-configuring two parking areas; creating a painted center median with …

On Hamilton’S Characteristic Functions For Reflection, Brendan Guilfoyle, Wilhelm Klingenberg

Publications

We review the complex differential geometry of the space of oriented affine lines in R3 and give a description of Hamilton’s characteristic functions for reflection in an oriented C1 surface in terms of this geometry.

Evolution Of Equatorial Ionospheric Bubbles During A Large Auroral Electrojet Increase In The Recovery Phase Of A Magnetic Storm, M. J. Keskinen, S. L. Ossakow, Bela G. Fejer, J. Emmert

Bela G. Fejer

[1] We present a model and observations of the evolution of equatorial ionospheric bubbles during a large auroral electrojet (AE) index increase in the recovery phase of a geomagnetic storm. Using a three-dimensional time-dependent numerical simulation model, we find, for the 19–21 October 1998 storm, that the equatorial bubble evolution is different during storm time as compared to quiet time conditions. We have found that the storm time vertical drift in conjunction with reduced off-equatorial E region shorting is the primary mechanism that distinguishes the large AE increase recovery phase storm time evolution from the quiet time case. Comparison of …

Mathematically Promising Students From The Space Age To The Information Age, Linda Jensen Sheffield

The Mathematics Enthusiast

On October 4, 1957, with the launch of Sputnik 1 by the Soviet Union, the world entered the Space Age and the United States became quite concerned that the Soviet Union had a head start in the space race. A year later, realizing that the support of gifted and talented mathematics and science students was critical to national security, the United States federal government passed the National Defense Education Act (NDEA), providing aid to education in the United States at all levels, primarily to stimulate the advancement of education in science, mathematics, and modern foreign languages. Also, during this time, …

Tme's Worldwide Circulation Statistics

The Mathematics Enthusiast

No abstract provided.

Not Out Of The Blue: Historical Roots Of Mathematics Education In Italy, Fulvia Furinghetti

The Mathematics Enthusiast

In this note I outline some elements of the history of mathematics education in Italy. Initially the chief characters were mathematicians who played a role in designing curricula and in editing textbooks. The development of the Italian community of mathematics educators towards the present day trend in research was fostered by participation in international activities after the Second World War. I also identify some elements of continuity with the past to stress the influence of some mathematicians in the development of present research.

Algorithmic Problems In Junior Contests In Latvia, Agnis Andžans, Inese Berzina, Dace Bonka

The Mathematics Enthusiast

Mathematical contests are of great importance for advanced education in Latvia today. Their content must be well-balanced and must correspond to the inner logic and recent trends of mathematics. A classification of algorithmic problems and characteristic examples are considered.

Geometric Restrictions On Producible Polygonal Protein Chains, Erik D. Demaine, Stefan Langerman, Joseph O'Rourke

Computer Science: Faculty Publications

Fixed-angle polygonal chains in three dimensions serve as an interesting model of protein backbones. Here we consider such chains produced inside a "machine" modeled crudely as a cone, and examine the constraints this model places on the producible chains. We call this notion producible, and prove as our main result that a chain whose maximum turn angle is α is producible in a cone of half-angle ≥ α if and only if the chain is flattenable, that is, the chain can be reconfigured without self-intersection to lie flat in a plane. This result establishes that two seemingly disparate classes of …

Simulations Of Black Hole Air Showers In Cosmic Ray Detectors, Eun-Joo Ahn, Marco Cavaglia

Physics Faculty Research & Creative Works

We present a comprehensive study of TeV black hole events in Earth's atmosphere originated by cosmic rays of very high energy. An advanced fortran Monte Carlo code is developed and used to simulate black hole extensive air showers from ultrahigh-energy neutrino-nucleon interactions. We investigate the characteristics of these events, compare the black hole air showers to standard model air showers, and test different theoretical and phenomenological models of black hole formation and evolution. The main features of black hole air showers are found to be independent of the model considered. No significant differences between models are likely to be observed …

Innovative Solutions To Human–Wildlife Conflicts

United States Department of Agriculture Wildlife Services: Staff Publications

Contents

Introduction
Developing Methods
Bird Research Program
Mammal Research Program
Product Development Research Program
Program Support
Wildlife Disease Research Program
Providing Wildlife Services
National Support
International Cooperation
Valuing and Investing in People
2005 Publication Awards
Supporting Student Research
Enhancing Information and Communication
Information Services
Seminars
Meetings, Workshops, and Conference Presentations
Publications

Macroscopic Computational Model Of Dielectric Barrier Discharge Plasma Actuators, Timothy R. Klein

Theses and Dissertations

Recent progress in the generation and sustainment of gas discharges at atmospheric pressure has energized research in the field of plasma-aerodynamics. Plasma actuators are promising devices that achieve flow control with no moving parts, do not alter the airfoil shape and place no parts in the flow. The operation of a plasma actuator is examined using a macroscopic (force and power addition) computational fluid dynamic model of a dielectric barrier discharge, DBD, in Fluent. A parametric approach is adopted to survey the range of requisite magnitudes of momentum and energy delivered to the flow field and to identify the effects …

Surface And Acidic Properties Of Mixed Zirconium And Titanium Oxides, Sofi-Rosamelia Bahgat Mahmoud Bahgat

Archived Theses and Dissertations

he surface and acidic properties of mixed sulfated zirconium and titanium oxides were investigated in the present study. One mode of preparation was followed entailing the use of zirconium sulfate and titanium oxysulfate as starting materials in a 1:1 ratio, and ammonium hydroxide as a precipitating agent. The resulting oxides were subjected to different extents of washing with water to vary their sulfate content. The mixed oxides were then analyzed by nitrogen adsorption, infrared spectroscopy, differential thermal analysis, thermogravimetric analysis, and elemental analysis for sulfur content. The number of acidic sites was determined from the saturation values of the adsorption …

Trap Loss In A Dual-Species Rb-Ar* Magneto-Optical Trap, H. C. Busch, M. K. Shaffer, E. M. Ahmed, C. I. Sukenik

Physics Faculty Publications

We have investigated trap loss in a dual-species magneto-optical trap (MOT) comprised of 85Rb and metastable 40Ar. We measure the trap loss rate coefficients for each species due to the presence of the other as a function of trap light intensity. We clearly identify both Penning ionization of Rb by Ar* and associative ionization to form the molecular ion RbAr+ as two of the trap loss channels. We have also measured the trap loss rate coefficient for the Ar* MOT alone and observe production of Ar+ and Ar2+ ions.

Enzyme Dynamics Along The Reaction Coordinate: Critical Role Of A Conserved Residue, Evgueni Kovriguine, J. Patrick Loria

Chemistry Faculty Research and Publications

Conformational flexibility of the enzyme architecture is essential for biological function. These structural transitions often encompass significant portions of the enzyme molecule. Here, we present a detailed study of functionally relevant RNase A dynamics in the wild type and a D121A mutant form by NMR spin-relaxation techniques. In the wild-type enzyme, the dynamic properties are largely conserved in the apo, enzyme−substrate, and enzyme−product complexes. In comparison, mutation of aspartic acid 121 to alanine disrupts the timing of active-site dynamics, the product-release step, and global conformational changes, indicating that D121 plays a significant role in coordinating the dynamic events in RNase …

Scalable Authentication Of Mpeg-4 Streams, Yongdong Wu, Robert H. Deng

Research Collection School Of Computing and Information Systems

This paper presents three scalable and efficient schemes for authenticating MPEG-4 streams: the Flat Authentication Scheme, the Progressive Authentication Scheme, and the Hierarchical Authentication Scheme. All the schemes allow authentication of MPEG-4 streams over lossy networks by integrating seamlessly digital signatures and erasure correction coding with MPEG-4's fine granular scalability. A prominent feature of our schemes is their "sign once, verify many ways" property, i.e., they generate only one digital signature per compressed MPEG-4 object group, but allow clients to verify the authenticity of any down-scaled version of the original signed object group.

Sustainable Development And National Security, Sanford E. Gaines

William & Mary Environmental Law and Policy Review

No abstract provided.

Restructuring America's Government To Create Sustainable Development, Jeffrey Rudd

William & Mary Environmental Law and Policy Review

No abstract provided.

Double Resonance Spectroscopy Of The B″B̅ 1Σu+ State Of H2, R. C. Ekey, A. Marks, Elizabeth Mccormack

Physics Faculty Research and Scholarship

Double resonance spectroscopy via the EF (1)Sigma(+)(g),nu'(EF)=6,J(') state has been used to probe the rovibrational structure of the ungerade double-well B-n(B) over bar (1)Sigma(+)(u) state of H-2. Transitions to the B-n(B) over bar (1)Sigma(+)(u),nu((B) over bar)=17-35,J=0-4 levels of the outer-well and to the nu(n)(B)((B) over bar)=46-50,J=0-4 levels of the combined inner and outer wells above the barrier have been recorded by detecting both molecular and atomic ion production as a function of energy by using a time of flight mass spectrometer. Theoretical energy calculations incorporating the most recent potential curves have been used to aid in the assignment of observed …

Ƒ-Electron Correlations In Nonmagnetic Ce Studied By Means Of Spin-Resolved Resonant Photoemission, S. W. Yu, Takashi Komesu, B. W. Chung, Simon A. Morton, James G. Tobin, George Daniel Waddill

Physics Faculty Research & Creative Works

We have studied the spin-spin coupling between two f electrons of nonmagnetic Ce by means of spin-resolved resonant photoemission using circularly polarized synchrotron radiation. The two f electrons participating in the 3d5/2-->4f resonance process are coupled in a singlet while the coupling is veiled in the 3d3/2-->4f process due to an additional Coster-Kronig decay channel. The identical singlet coupling is observed in the 4d-->4f resonance process. Based on the Ce measurements, it is argued that spin-resolved resonant photoemission is one approach to study the correlation effects, particularly in the form of spin, in the rare earths.