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The University of Maine

2003

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Articles 61 - 77 of 77

Full-Text Articles in Physical Sciences and Mathematics

Maine's Salt Marshes: Their Functions, Values, And Restoration, Michele Dionne, Erno Bonebakker, Kristen Grant Jan 2003

Maine's Salt Marshes: Their Functions, Values, And Restoration, Michele Dionne, Erno Bonebakker, Kristen Grant

Maine Sea Grant Publications

This illustrated resource booklet for Maine residents educates the reader about the properties and functions of salt marshes. It also facilitates leadership and participation in restoration efforts by providing information for further resources.

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Field Guide To Phytoplankton In The Gulf Of Maine, Susan White Jan 2003

Field Guide To Phytoplankton In The Gulf Of Maine, Susan White

Maine Sea Grant Publications

This field 50-leaf guide was created for the citizen volunteers who provide a first-alert system to the Maine Department of Marine Resources by watching for the presence of potentially toxic phytoplankton along the coast. The waterproof cards (held in a three-ring binder) provide color images from light microscopes at 200X or 400X, as well as identifying characteristics, natural history facts, and known impacts of 22 types of phytoplankton. A glossary, size chart, bibliography, and a brief about zooplankton are also included.

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Performance Advantages Of Maximum Likelihood Methods In Prbs-Modulated Time-Of-Flight Energy Loss Spectroscopy, Zhongyu Yang Jan 2003

Performance Advantages Of Maximum Likelihood Methods In Prbs-Modulated Time-Of-Flight Energy Loss Spectroscopy, Zhongyu Yang

Electronic Theses and Dissertations

This thesis describes the design, experimental performance, and theoretical simulation of a novel time-of-flight analyzer that was integrated into a high resolution electron energy loss spectrometer (TOF-HREELS). First we examined the use of an interleaved comb chopper for chopping a continuous electron beam. Both static and dynamic behaviors were simulated theoretically and measured experimentally, with very good agreement. The finite penetration of the field beyond the plane of the chopper leads to non-ideal chopper response, which is characterized in terms of an "energy corruption" effect and a lead or lag in the time at which the beam responds to the …

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Crevassing And Calving Of Glacial Ice, James Patrick Kenneally Jan 2003

Crevassing And Calving Of Glacial Ice, James Patrick Kenneally

Electronic Theses and Dissertations

Calving of ice is a relatively new area of research in the still young field of glaciology. In the short time that calving has been studied, it has been mainly treated as an afterthought, with the predominant mode of thinking being that it will happen so to concern oneself with why is not important. Many studies dealt with observations of calving front positions over time vs. ice velocity in an attempt to quantify the calving rate as the difference between the two, while others have attempted to deduce some empirical relationship between calving rate and variables such as water depth …

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Design, Implementation And Assessment Of An Earth Systems Science Course For Secondary Teachers, Jeffery C. Owen Jan 2003

Design, Implementation And Assessment Of An Earth Systems Science Course For Secondary Teachers, Jeffery C. Owen

Electronic Theses and Dissertations

In the fall of 2002 the Department of Earth Sciences at the University of Maine piloted an innovative course developed as a core offering for the new Master of Science in Teaching program. A team of four instructors comprised of two Earth Sciences faculty and two science educators developed the course and implemented it with nine students- six in-service teachers and three pre-service teachers. The course addressed multiple needs of secondary teachers through the integration of instruction in curriculum design, pedagogy, assessment, and classroom-level educational research, and earth systems science content. The components of instruction taught in the course included: …

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Soil Solution Dynamics In Response To Elevated Nitrogen And Sulfur Treatments At The Bear Brook Watershed In Maine, Johanna Szillery Jan 2003

Soil Solution Dynamics In Response To Elevated Nitrogen And Sulfur Treatments At The Bear Brook Watershed In Maine, Johanna Szillery

Electronic Theses and Dissertations

Base cation depletion in forest soils of northeastern North America is a continuing concern because of the ongoing elevated deposition of sulfur (S) and nitrogen (N), intensive-management practices, and the often poorly understood implications of land-use history on modem ecosystem function. At the Bear Brook Watershed in Maine (BBWM), one of two paired, forested watersheds has been subjected to experimental additions of S and N for over a decade. Treatments consist of 28.8 kg S ha-' yr-' and 25.2 kg N ha-' yr-' in the form of granular (NH&SO4 applied bimonthly by helicopter. Ceramic cup tension lysimeters were used to …

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People In Nature: Environmental History Of The Kennebec River, Maine, Daniel J. Michor Jan 2003

People In Nature: Environmental History Of The Kennebec River, Maine, Daniel J. Michor

Electronic Theses and Dissertations

The quality of a river affects the tributaries, lakes, and estuary it feeds; it affects the wildlife and vegetation that depend on the river for energy, nutrients, and habitat, and also affects the human community in the form of use, access, pride, and sustainability. In an age of mass consumerism and materialism, dwindling natural resources and wild spaces, and advanced technology, the ability to make a living and at the same time enjoy the benefits of rural living is increasingly difficult. Using the entire Kennebec River watershed as the scale of investigation with particular focus on the river corridor itself, …

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Renormalization-Group Studies Of Three Model Systems Far From Equilibrium, Ivan T. Georgiev Jan 2003

Renormalization-Group Studies Of Three Model Systems Far From Equilibrium, Ivan T. Georgiev

Electronic Theses and Dissertations

This thesis describes the development of analytical and computational techniques for systems far from equilibrium and their application to three model systems. Each of the model systems reaches a non-equilibrium steady state and exhibits one or more phase transitions. We first introduce a new position-space renormalization-group approach and illustrate its application using the one-dimensional fully asymmetric exclusion process. We have constructed a recursion relation for the relevant dynamic parameters for this model and have reproduced all of the important critical features of the model, including the exact positions of the critical point and the first and second order phase boundaries. …

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A Mathematical Model For Simplifying Representations Of Objects In A Geographic Information System, Gabriel Perrow Jan 2003

A Mathematical Model For Simplifying Representations Of Objects In A Geographic Information System, Gabriel Perrow

Electronic Theses and Dissertations

The study of operations on representations of objects is well documented in the realm of spatial engineering. However, the mathematical structure and formal proof of these operational phenomena are not thoroughly explored. Other works have often focused on query-based models that seek to order classes and instances of objects in the form of semantic hierarchies or graphs. In some models, nodes of graphs represent objects and are connected by edges that represent different types of coarsening operators. This work, however, studies how the coarsening operator "simplification" can manipulate partitions of finite sets, independent from objects and their attributes. Partitions that …

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Solar And Wind Energy Development In Maine: 1973-1997, Evan Rallis Jan 2003

Solar And Wind Energy Development In Maine: 1973-1997, Evan Rallis

Electronic Theses and Dissertations

Focusing on how Maine reflected, as well as stood out from national trends in the development of wind and solar energy, this study concentrates particularly on how Maine state government and environmental groups contributed to this development, as well as on the technological progress of these energy sources. It draws primarily on state government documents, newspapers, and periodicals for evidence. The 1973-74 energy crisis, combined with the rise of the environmental movement, led to an increased exploration of alternative energy sources, in particular those that were relatively friendly to the environment like solar and wind energy. Attempts to utilize these …

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Stable Sulfur Isotope Rations From West Antarctica And The Tien Shan Mountains: Sulfur Cycle Characteristics From Two Environmentally Distinct Areas, Lee Pruett Jan 2003

Stable Sulfur Isotope Rations From West Antarctica And The Tien Shan Mountains: Sulfur Cycle Characteristics From Two Environmentally Distinct Areas, Lee Pruett

Electronic Theses and Dissertations

Continuous snow pit and ice core samples from two distinct environments (West Antarctica and the Tien Shan mountains in central Asia) were analyzed for 6 3 4 ~ and used to assess different regional sulfur cycle characteristics. In West Antarctica, 18 continuous samples were obtained from the RIDSA ice core (78.73"S, 116.33"W, 1740 m asl), covering the years 1935 to 1976. Each sample represents from 2 to 3 years of snow deposition, and the combination of summer and winter seasons varies by sample. 6 3 4 ~ values range from 3.1 %O to 9.9%0, and reflect the overall isotopic composition …

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An Information Theoretic Study Of The Ising Antiferromagnet With Quenched Dilution On A Triangular Lattice, Matthew D. Robinson Jan 2003

An Information Theoretic Study Of The Ising Antiferromagnet With Quenched Dilution On A Triangular Lattice, Matthew D. Robinson

Electronic Theses and Dissertations

This investigation applies information theoretic techniques to study the ordering and structure of the Ising antiferromagnet with quenched disorder on a triangular lattice. The pure system shows no phase transition due to the high degree of frustration present. However, when quenched vacancies are introduced randomly into this geometrically frustrated system, a phase transition at finite temperature, to an ordered phase, can arise. If the vacancies are introduced on all three sublattices of the triangular lattice, then a two-dimensional spin-glass transition occurs. If dilution takes place on only one sublattice, then the other two sublattices develop magnetiza- tions below the critical …

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The Distribution Of The Irreducibles In An Algebraic Number Field, Rebecca Rozario Jan 2003

The Distribution Of The Irreducibles In An Algebraic Number Field, Rebecca Rozario

Electronic Theses and Dissertations

The objective of this thesis is to study the distribution of the number of principal ideals generated by an irreducible element in an algebraic number field, namely in the non-unique factorization ring of integers of such a field. In particular we are investigating the size of M(x), defined as M ( x ) =∑ (α) α irred.|N (α)|≤≠ 1, where x is any positive real number and N (α) is the norm of α. We finally obtain asymptotic results for hl(x).

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12,000-Year Record Of Lake-Level And Vegetative Change At Mathews Pond, Piscataquis County, Maine, Usa, Andrea Masterman Nurse Jan 2003

12,000-Year Record Of Lake-Level And Vegetative Change At Mathews Pond, Piscataquis County, Maine, Usa, Andrea Masterman Nurse

Electronic Theses and Dissertations

This study of late-glacial and Holocene changes in lake-level and vegetation at Mathews Pond contributes new information about Holocene environments in northeastern North America. The research establishes a 12,000-year record of paleohydrology for the watershed adjacent to Big Reed Forest Reserve, the largest stand of old-growth forest in the northeastern United States. Mathews Pond is a 7.4 ha, closed-basin, groundwaterseepage lake located in an upland, forested region of the Aroostook River drainage system. Glacial meltwater briefly filled the basin - 13.0 ka (1 ka = 1000 I4C yr BP)). The lake existed as a shallow pool in the deep area …

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Extracting Movement Patterns Using Fuzzy And Neuro-Fuzzy Approaches, Haci Mustafa Palancioglu Jan 2003

Extracting Movement Patterns Using Fuzzy And Neuro-Fuzzy Approaches, Haci Mustafa Palancioglu

Electronic Theses and Dissertations

Several applications generate large volumes of data on movements including vehicle navigation, fleet management, wildlife tracking and in the near future cell phone tracking. Such applications require support to manage the growing volumes of movement data. Understanding how an object moves in space and time is fundamental to the development of an appropriate movement model of the object. Many objects are dynamic and their positions change with time. The ability to reason about the changing positions of moving objects over time thus becomes crucial. Explanations on movements of an object require descriptions of the patterns they exhibit over space and …

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Knowledge-Based Task Structure Planning For An Information Gathering Agent, John Phelps Jan 2003

Knowledge-Based Task Structure Planning For An Information Gathering Agent, John Phelps

Electronic Theses and Dissertations

An effective solution to model and apply planning domain knowledge for deliberation and action in probabilistic, agent-oriented control is presented. Specifically, the addition of a task structure planning component and supporting components to an agent-oriented architecture and agent implementation is described. For agent control in risky or uncertain environments, an approach and method of goal reduction to task plan sets and schedules of action is presented. Additionally, some issues related to component-wise, situation-dependent control of a task planning agent that schedules its tasks separately from planning them are motivated and discussed.

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An Interhemispheric Comparison Of The Recession Of Mountain Glaciers In The Last 150 Years, Colby Smith Jan 2003

An Interhemispheric Comparison Of The Recession Of Mountain Glaciers In The Last 150 Years, Colby Smith

Electronic Theses and Dissertations

Historical records in the Northern Hemisphere show overall glacier retreat since about AD 1860-1890. A glacial retreat of similar timing and magnitude in the Southern Hemisphere is less well established. Comparison of the timing and magnitude of glacial recession in the two polar hemispheres over the past century can elucidate mechanisms driving global climatic change. In order to determine the recession patterns of Murchison, Hooker, and Tasman Glaciers in the Southern Alps of New Zealand, geomorphic maps were constructed and recent glacial deposits were dated using lichenometry. Since the mid-to-late nineteenth century, each glacier terminus has retreated about 1.5 km. …

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