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2003

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Articles 151 - 180 of 3876

Full-Text Articles in Physical Sciences and Mathematics

Design And Analysis Of Cylindrical Antiresonant Reflecting Optical Waveguide, Chyng Wen Tee, S. F. Yu Dec 2003

Design And Analysis Of Cylindrical Antiresonant Reflecting Optical Waveguide, Chyng Wen Tee, S. F. Yu

Research Collection Lee Kong Chian School Of Business

A field-transfer matrix method is developed to analyze the modal characteristics of cylindrical multilayered waveguides with axis-symmetric geometry. A new design rule for cylindrical antiresonant reflecting optical waveguides (ARROWs), based on a three-step design process, is also proposed to minimize the radiation loss of the fundamental leaky mode. In addition, a simple approach is suggested to estimate the optimum core diameter of the cylindrical ARROWs for optimum radiation loss and radiation loss margin. Hence, it can be shown that an extra high index cladding layer is good enough to reduce the radiation loss as well as to maintain a reasonably …


Using Spreadsheets In Geoscience Education: Survey And Annotated Bibliography Of Articles In The Journal Of Geoscience Education Through 2003, Beth Fratesi, H. L. Vacher Dec 2003

Using Spreadsheets In Geoscience Education: Survey And Annotated Bibliography Of Articles In The Journal Of Geoscience Education Through 2003, Beth Fratesi, H. L. Vacher

School of Geosciences Faculty and Staff Publications

Thirty-eight papers published in the Journal of Geoscience Education ( JGE) from 1989 through 2003 explicitly use or recommend the use of spreadsheets as part of classroom or field exercises, projects, or entire courses. Many of the papers include the spreadsheets, and some include the equations. The papers demonstrate how spreadsheets allow students to explore a subject through problem-oriented, interactive, and quantitative exercises. We provide an annotated bibliography and classify the 38 JGE papers by spreadsheet use, mathematics skill area, and geologic subdiscipline. Our discussion of five selected articles — abundance of elements in the Earth’s crust; directional properties of …


Trust, Collaboration, And Financial Return In Conservation/Development Partnerships, New England Environmental Finance Center Dec 2003

Trust, Collaboration, And Financial Return In Conservation/Development Partnerships, New England Environmental Finance Center

Economics and Finance

In early 2002 the New England Environmental Finance Center hosted a series of roundtable discussions among municipal officials, residential developers, land trust representatives, and others about "Innovative Approaches to Land Conservation and Smart Growth". Among our observations was that for many of the over 20 conservation/development partnerships we discussed in the series, creation and maintenance of trust was central to success or failure of various stages of the partnership. This suggested a link between creation of trust and financial return for traditionally opposed project partners.

To further examine this matter, we interviewed 11 round table participants and asked questions about …


Specific Dynamic Action, Growth And Development In Larval Atlantic Cod, Gadus Morhua, Jessica A. Geubtner Dec 2003

Specific Dynamic Action, Growth And Development In Larval Atlantic Cod, Gadus Morhua, Jessica A. Geubtner

Electronic Theses and Dissertations

The larval stage of marine fish is a period of rapid growth and development. Atlantic cod (Gadus morhua) are approximately 4-5 rnm in length upon hatch and feed endogenously from their yolk sac for the first week. After this time, larval cod must successfully capture live prey to survive and to fuel high growth rates of greater than 10%d". Previous studies have found that during exogenous feeding and at growth rates greater than 8%d1 larvae experience what appears to be cost free growth, where mass specific metabolic rate does not decrease with increasing mass. Due to size and condition constraints …


The Role Of Larval Thermal Tolerance In The Distribution Of Blue Mussel Species Within The Gulf Of Maine, Susan J. Limbeck Dec 2003

The Role Of Larval Thermal Tolerance In The Distribution Of Blue Mussel Species Within The Gulf Of Maine, Susan J. Limbeck

Electronic Theses and Dissertations

Two species of blue mussel, Myrilus edulis and Myrilus trossulus, are sympatric throughout much of the Canadian Maritime Provinces and into the Gulf of Maine. While the distribution of M edulis extends south to the Mid-Atlantic, that of M. trossulus ends abruptly in the Gulf of Maine. I have hypothesized that these differences in adult distribution are the result of species-specific variation in larval thermal tolerances. Previously, it has been shown that when reared at 20 OC, from 36 hour post-fertilization through settlement, M. trossulus had significantly higher mortality rates than M. edulis. This study examined whether species-specific differences in …


Analysis Of The Spatial Dynamics Of The American Lobster (Homarus Americanus) Fishery Along The Coast Of Maine, Kevin M. Scheirer Dec 2003

Analysis Of The Spatial Dynamics Of The American Lobster (Homarus Americanus) Fishery Along The Coast Of Maine, Kevin M. Scheirer

Electronic Theses and Dissertations

The American lobster (Homarus americanus) supports the most valuable commercial fishery in the northeastern United States, thus the fishery is critical to Maine's economy. No systematic study has been done to collect information about, identify, and quantify the spatial dynamics of the Maine lobster fishery. This project helps to provide a better understanding of Maine's lobster fishery dynamics, and it will aid f'iture efforts to improve the stock assessment of Maine's lobster fishery. The analysis consists of three distinct parts: (1) comparison of data collected by two separate fishery dependent sampling programs; (2) spatial analysis of electronic logbook data; and …


Charge Transfer In Slow Collisions Of C⁴⁺ With H Below 1 Kev/Amu, Chen-Nan Liu, Anh-Thu Le, C. D. Lin Dec 2003

Charge Transfer In Slow Collisions Of C⁴⁺ With H Below 1 Kev/Amu, Chen-Nan Liu, Anh-Thu Le, C. D. Lin

Physics Faculty Research & Creative Works

We reexamined charge-transfer cross sections for C⁴⁺ + H collisions for energies from 1 meV/amu to 1 keV/amu using the recently developed hyperspherical close-coupling method. Our results agree with several previous theoretical calculations using molecular-orbital expansion. However, these converged theoretical predictions do not agree with total cross sections from the merged-beam experiments.


Nonlethal Techniques For Managing Predation: Primary And Secondary Repellents, John A. Shivik, Adrian Treves, Peggy Callahan Dec 2003

Nonlethal Techniques For Managing Predation: Primary And Secondary Repellents, John A. Shivik, Adrian Treves, Peggy Callahan

United States Department of Agriculture Wildlife Services: Staff Publications

Conservation biology requires the development of practical tools and techniques to minimize conflicts arising from human modification of ecosystems. We applied behavioral theory of primary and secondary repellents to predator management by using aversive stimulus devices (electronic training collars) and disruptive stimulus devices (behavior-contingent audio and visual repellents) in a multipredator (Canis lupus, Haliaeetus leucocephalus, Ursus spp. ) study in the United States. We examined fladry and a newly developed disruptive stimulus device contingent upon behavior on six wolf territories in Wisconsin, (US.A.) and determined that the disruptive stimulus device gave the greatest degree of protection from predation. We …


Wolf Depredation Trends And The Use Of Fladry Barriers To Protect Livestock In Western North America, Marco Musiani, Charles Mamo, Luigi Boitani, Carolyn Callaghan, C. Cormack Gates, Livia Mattei, Elisabetta Visalberghi, Stewart W. Breck, Giulia Volpi Dec 2003

Wolf Depredation Trends And The Use Of Fladry Barriers To Protect Livestock In Western North America, Marco Musiani, Charles Mamo, Luigi Boitani, Carolyn Callaghan, C. Cormack Gates, Livia Mattei, Elisabetta Visalberghi, Stewart W. Breck, Giulia Volpi

United States Department of Agriculture Wildlife Services: Staff Publications

In Alberta, Canada (1982-2001), and in Idaho, Montana, and Wyoming, United States (1987-2001), wolves (Canis lupus) killed various domestic animals, among which the major prey were sheep in the United States (68%, n = 494) and cattle in Canada (95%; n = 1633). Under recovery programs, the wolf population increased in the United States, and depredation events increased proportionately. In both countries, the number of domestic animals killed each year was correlated with the number of wolves killed by government authorities for depredation management. We tested the ability of anti-wolf barriers made of flags hanging from ropes to impede wolf …


Determination Of Spatial Strata For Environmental Regulatory Purposes, John Edward Daniels Dec 2003

Determination Of Spatial Strata For Environmental Regulatory Purposes, John Edward Daniels

Dissertations

This dissertation introduces spatial strata modelling, a methodology that combines spatial statistics, cluster analysis, and geographic information system theories to analyze the background level of naturally occurring contaminants of concern (COCs). The objective of spatial strata modelling is to divide a geographic area of interest into mutually exclusive geographic zones (spatial strata): with each stratum representing a different level of COC concentration. An estimate of each stratum's COC concentration level, representing an upper regulatory limit, will also be provided. Data provided by the Michigan Department of Environmental Quality describing the spatial location and arsenic concentrations of 211 Michigan sites (arsenic …


Geochemical And Isotopic Characterization Of Shallow Basinal Brines From The Makgadikgadi Pans Complex, Northeastern Botswana: Determination Of The Sources Of Salinity, Loago N. Molwalefhe Dec 2003

Geochemical And Isotopic Characterization Of Shallow Basinal Brines From The Makgadikgadi Pans Complex, Northeastern Botswana: Determination Of The Sources Of Salinity, Loago N. Molwalefhe

Dissertations

Isotopes and chemical tracers have been used to constrain the sources and causes of salinity in shallow groundwater brine from the Makgadikgadi Basin, northeastern Botswana. The brine is massively rich in chloride and sodium, and moderately rich in carbonates, sulphate and potassium, and is distinctively poor in divalent cationic species. Various models that have been advanced to explain the origin of the brines include evaporative enrichment at the surface and density-induced infiltration, dissolution of evaporites, and trapped connate water.

This study presents the compositional variability and behaviors of ·the stable isotopes of carbon (S13C) and oxygen (S18 …


The John Muir Newsletter, Winter 2003/2004, The John Muir Center For Environmental Studies Dec 2003

The John Muir Newsletter, Winter 2003/2004, The John Muir Center For Environmental Studies

Muir Center Newsletters (1981-2015)

Newsletter ^ERSnY OF THE PACIFIC, STOCKTON. CA Volume 14, Number l Winter 2008-2004 John Mum and Civilization Corinne Wong, Clackamas, Oregon (Editor's note: Corinne Wong is a graduating senior double majoring in Environmental Studies and Geosciences. In addition, Wong is a student athlete in women's basketball at the University of the Pacific. This paper was prepared in the Fall of 2002 for an undergraduate course, "John Muir and the Environment.") J-ohn Muir was very much a man of nature. He was a geologist, botanist, mountaineer, nature writer, and, as most commonly recognized, a conservationist. His love for nature is a …


Deconstructing Bases: Fair, Fitting, And Fast Bases, Thomas Q. Sibley Dec 2003

Deconstructing Bases: Fair, Fitting, And Fast Bases, Thomas Q. Sibley

Mathematics Faculty Publications

No abstract provided.


A High Shear-Rate Optical Rheometer For Complex Fluids, Khaled S. Mriziq Dec 2003

A High Shear-Rate Optical Rheometer For Complex Fluids, Khaled S. Mriziq

Doctoral Dissertations

A parallel-plate optical rheometer in a magnetic-disc drive configuration has been designed and constructed of optically transparent materials and operating with a very small gap to obtain rheological and structural measurements at very high shear rates.

The friction force at the disk-slider interface has been measured as a function of sliding speed while the film thickness was monitored in situ using a capacitance technique. The shear rate is calculated from the film thickness and the sliding speed. A thin film can be applied on the disk, which allows very high-shear-rate measurements at low sliding speeds with negligible viscous heating.

Both …


Current Perspectives On Energy And Mass Fluxes In Volcanic Arcs, William Leeman, Jon Davidson, Tobias Fischer, Anita Grunder, Mark Reagan, Martin J. Streck Dec 2003

Current Perspectives On Energy And Mass Fluxes In Volcanic Arcs, William Leeman, Jon Davidson, Tobias Fischer, Anita Grunder, Mark Reagan, Martin J. Streck

Geology Faculty Publications and Presentations

Volcanoes of the Pacific Ring of Fire and other convergent margins worldwide are familiar manifestations of nature's energy, account for about 25% of global volcanic outputs, dominate volcanic gas emissions to the atmosphere, and pose significant physical threats to a large human population. Yet the processes behind this prolific activity remain poorly understood.

An international "State of the Arc" (SOTA) conference was held in August on the slopes of Mt. Hood, Oregon, to address current views on the energy and mass fluxes in volcanic arcs. This meeting brought together some 90 leading experts and students of subduction zones and their …


A Modeling Experiment On The Grounding Of An Ice Shelf In The Central Arctic Ocean During Mis 6, Martin Jakobsson, M Siegert, Mark Paton Dec 2003

A Modeling Experiment On The Grounding Of An Ice Shelf In The Central Arctic Ocean During Mis 6, Martin Jakobsson, M Siegert, Mark Paton

Center for Coastal and Ocean Mapping

High-resolution chirp sonar subbottom profiles from the Lomonosov Ridge in the central Arctic Ocean, acquired from the Swedish icebreaker Oden in 1996, revealed large-scale erosion of the ridge crest down to depths of 1000 m below present sea level [Jakobsson, 1999]. Subsequent acoustic mapping during the SCICEX nuclear submarine expedition in 1999 showed glacial fluting at the deepest eroded areas and subparallel ice scours from 950 m water depth to the shallowest parts of the ridge crest [Polyak et al., 2001]. The directions of the mapped glaciogenic bed-forms and the redeposition of eroded material on the Amerasian side of the …


Isotropic Loop Quantum Cosmology With Matter. Ii. The Lorentzian Constraint, F. Hinterleitner, Seth Major Dec 2003

Isotropic Loop Quantum Cosmology With Matter. Ii. The Lorentzian Constraint, F. Hinterleitner, Seth Major

Articles

The Lorentzian Hamiltonian constraint is solved for isotropic loop quantum cosmology coupled to a massless scalar field. As in the Euclidean case, the discreteness of quantum geometry removes the classical singularity from the quantum Friedmann models. In spite of the absence of the classical singularity, a modified DeWitt initial condition is incompatible with a late-time smooth behavior. Further, the smooth behavior is recovered only for positive or negatives times but not both. An important feature, which is shared with the Euclidean case, is a minimal initial energy of the order of the Planck energy required for the system to evolve …


Survey Of Health Effects Among Residents Adjacent To A National Priority List Site In Ssouthwest Virginia., Danette Haywood Dec 2003

Survey Of Health Effects Among Residents Adjacent To A National Priority List Site In Ssouthwest Virginia., Danette Haywood

Electronic Theses and Dissertations

The Saltville Waste Disposal Site is a National Priority List site used during the 77- year operation (1895–1972) of an electrolytic chlorine and caustic soda plant. A cross-sectional study was conducted to determine disease prevalence among Saltville Medical Center (SMC) patients. Diseases associated with chronic exposures to mercury, arsenic, and lead were reviewed in patient records and these data were analyzed. Ratios of illness observed at the SMC were compared to health studies of similar environmental exposures and disease prevalence among residents of neighboring communities. Prevalence ratios were calculated for residents and non-residents of Saltville who were SMC patients. Saltville …


Host-Pathogen Interactions In A Segregating Population Of Bc2f2 Hybrid Castanea Dentata And Other Chesnut Hybirds After Exposure To Hypovirus-Containing And Hypvirus-Free Strains Of Cryphonectria Parasitica, Stephen Henry Alexander Dec 2003

Host-Pathogen Interactions In A Segregating Population Of Bc2f2 Hybrid Castanea Dentata And Other Chesnut Hybirds After Exposure To Hypovirus-Containing And Hypvirus-Free Strains Of Cryphonectria Parasitica, Stephen Henry Alexander

Masters Theses and Doctoral Dissertations

An F2 population of second backcross interspecific hybrid chestnut trees (BC2F2) and the progeny of the Chattanooga Chestnut Tree Project (CCTP) breeding program were exposed to three isogenic strains of Cryphonectria parasitica. Strain Ep155 (virus-free) was used to screen the 4- 7 year old chestnut trees for resistance to chestnut blight disease. Two virus-containing, hypovirulent strains, Ep155(CHV1-Euro7) and Ep155(CHV1-Ep713), were used to investigate interactions of host disease resistance and expression ofhypovirulence. The BC2F2 population varied from highly susceptible to highly resistant, as measured by Ep155 (virus-free) canker length at 95 days. Disease resistance in the CCTP population varied from highly …


Parallaxes And Distance Estimates For 14 Cataclysmic Variable Stars, John R. Thorstensen Dec 2003

Parallaxes And Distance Estimates For 14 Cataclysmic Variable Stars, John R. Thorstensen

Dartmouth Scholarship

I used the 2.4 m Hiltner Telescope at MDM Observatory in an attempt to measure trigonometric parallaxes for 14 cataclysmic variable stars. Techniques are described in detail. In the best cases the parallax uncertainties are below 1 mas, and significant parallaxes are found for most of the program stars. A Bayesian method that combines the parallaxes together with proper motions and absolute magnitude constraints is developed and used to derive distance estimates and confidence intervals. The most precise distance derive here is for WZ Sge, for which I find 43: 3.1:6 1:5 pc. Six Luyten Half-Second stars with previous precise …


Effect Of Heavy Metals On Bacteria, Elena Vratonjic Dec 2003

Effect Of Heavy Metals On Bacteria, Elena Vratonjic

Theses and Dissertations

Heavy metals have become devastating environmental contaminants due to their widespread use in the manufacture of electronics, plastics, batteries and dyes. The discharge of heavy metals into the environment has caused concern about their effects on the ecosystem. Many metals are essential for growth in small amounts. However, at higher concentrations heavy metals are toxic because they bind to organic compounds. This accounts for their effects on some important parts of the cell structure, like their ability to denature protein molecules. The initial objective of this study was to find out the growth rate of E.coli and M.roseus in the …


Constraint Datalog In Trust Management, Scot Anderson Dec 2003

Constraint Datalog In Trust Management, Scot Anderson

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Constraint Datalog holds an increasing role in Trust Management. We discuss several Trust Management systems and give a description of the environment and requirements for Trust Management. Constraint Datalog using addition constraints and approximation theory provides an expressive semantic with which to describe security policies for credentials, delegations and authorizations. Approximation theory allows halting in Constraint Datalog over addition constraints. We use the decision problem of Diophantine equations to show that Constraint Datalog over addition constraints is complete. Combining these two concepts provides an approximately complete, safe language. The problem of constant additions to closed languages provides reasons for using …


Predicting Nonlinear Network Traffic Using Fuzzy Neural Network, Zhaoxia Wang, Tingzhu Hao, Zengqiang Chen, Zhuzhi Yuan Dec 2003

Predicting Nonlinear Network Traffic Using Fuzzy Neural Network, Zhaoxia Wang, Tingzhu Hao, Zengqiang Chen, Zhuzhi Yuan

Research Collection School Of Computing and Information Systems

Network traffic is a complex and nonlinear process, which is significantly affected by immeasurable parameters and variables. This paper addresses the use of the five-layer fuzzy neural network (FNN) for predicting the nonlinear network traffic. The structure of this system is introduced in detail. Through training the FNN using back-propagation algorithm with inertia] terms the traffic series can be well predicted by this FNN system. We analyze the performance of the FNN in terms of prediction ability as compared with solely neural network. The simulation demonstrates that the proposed FNN is superior to the solely neural network systems. In addition, …


Xstamps: A Multiversion Timestamps Concurrency Control Protocol For Xml Data, Khin-Myo Win, Wee-Keong Ng, Ee Peng Lim Dec 2003

Xstamps: A Multiversion Timestamps Concurrency Control Protocol For Xml Data, Khin-Myo Win, Wee-Keong Ng, Ee Peng Lim

Research Collection School Of Computing and Information Systems

With the tremendous growth of XML data over the Web, efficient management of such data becomes a new challenge for database community. Several data management solutions, proposed in recent years, extend the capability of traditional database systems to meet the needs of XML data while alternative approaches introduce new generation databases, named as native XML database management systems. Although traditional databases have mature transaction management and concurrency control techniques, there is still a need to tailor techniques for native XML databases in order to deal with distinct characteristics of XML. In this paper, we propose XStamps, a multiversion timestamps concurrency …


Paper For An Educational Digital Library, Dion Hoe-Lian Goh, Yin-Leng Theng, Ming Yin, Ee Peng Lim Dec 2003

Paper For An Educational Digital Library, Dion Hoe-Lian Goh, Yin-Leng Theng, Ming Yin, Ee Peng Lim

Research Collection School Of Computing and Information Systems

GeogDL is a digital library of geography examination resources designed to assist students in revising for a national geography examination in Singapore. As part of an iterative design process, we carried out participatory design and brainstorming with student and teacher design partners. The first study involved prospective student design partners. In response to the first study, we describe in this paper an implementation of PAPER – Personalised Adaptive Pathways for Exam Resources – a new bundle of personalized, interactive services containing a mock exam and a personal coach. The mock exam provides a simulation of the actual geography examination while …


Probing Scattering Wave Functions Close To The Nucleus, Don H. Madison, Daniel Fischer, Matthew S. Foster, Michael Schulz, Robert Moshammer, Stephenie J. Jones, Joachim Hermann Ullrich Dec 2003

Probing Scattering Wave Functions Close To The Nucleus, Don H. Madison, Daniel Fischer, Matthew S. Foster, Michael Schulz, Robert Moshammer, Stephenie J. Jones, Joachim Hermann Ullrich

Physics Faculty Research & Creative Works

Recently, three-dimensional imaging of the ejected electrons following 100  MeV/amu C6+ single ionization of helium led to the observation of a new structure not predicted by theory [M. Schulz et al., Nature (London) 422, 48 (2003)]. Instead of the usual “recoil lobe” centered on the momentum-transfer axis, a ring-shaped structure centered on the beam axis was observed. New measurements at 2  MeV/amu exhibit a similar structure, which is now predicted by theory. We argue that the same theory failed at 100  MeV/amu because the faster projectiles probe distances much closer to the nucleus, where our multiple-scattering model is expected …


Irradiation Induced Order-Dis Order Transformations In Ni-Mo Alloys, Ovidiu F. Toader Dec 2003

Irradiation Induced Order-Dis Order Transformations In Ni-Mo Alloys, Ovidiu F. Toader

Dissertations

No abstract provided.


Pond-Breeding Amphibian Species Distributions In A Beaver-Modified Landscape, Acadia National Park, Mount Desert Island, Maine, Jesse Cunningham Dec 2003

Pond-Breeding Amphibian Species Distributions In A Beaver-Modified Landscape, Acadia National Park, Mount Desert Island, Maine, Jesse Cunningham

Electronic Theses and Dissertations

In order to maintain pond-breeding amphibian species richness, it is important to understand how both natural and anthropogenic disturbances affect species assemblages and individual species distributions both at the scale of individual ponds and at a larger landscape scale. The goal of this project was to investigate what characteristics of ponds and the surrounding wetland landscape were most effective in predicting pond-breeding species richness and the individual occurrence of wood frog (Rana sylvatica), bullfrog (Rana catesbeiana) and pickerel frog (Rana palustris) breeding sites in a beaver-modified landscape and how this landscape has changed over …


Development And Assessment Of A Spatial Decision Support System For Conservation Planning, Sean Murphy Dec 2003

Development And Assessment Of A Spatial Decision Support System For Conservation Planning, Sean Murphy

Electronic Theses and Dissertations

Land conservation is frequently cited as the most effective means of limiting the detrimental effects of anthropogenic forces on natural resources. Because governmental entities can be hampered by fiscal and political concerns, land trusts are increasing relied on to protect habitat. However, these groups often lack the analysis and research tools necessary to meet their mission. Geographic Information System (GIs) technologies such as Spatial Decision Support Systems (SDSS) offer the promise of allowing decision makers to explore their decision space at a landscape level of analysis. But critics have charged that research in this arena is largely anecdotal in nature. …


Uniform Approximation Of Continuous Functions On A Compact Riemann Surface By Elliptic Modular Forms, Michael Berg Dec 2003

Uniform Approximation Of Continuous Functions On A Compact Riemann Surface By Elliptic Modular Forms, Michael Berg

Mathematics, Statistics and Data Science Faculty Works

We show that the graded algebra of elliptic modular forms and their conjugates comprises a uniformly dense subspace of the space of all continuous functions on the compactification of the fundamental domain for the action of SL2(Z) on the complex upper half-plane by fractional linear transformations.