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Full-Text Articles in Physical Sciences and Mathematics

Modules Over Localized Group Rings For Groups Mapping Onto Free Groups, Nicholas Davidson May 2011

Modules Over Localized Group Rings For Groups Mapping Onto Free Groups, Nicholas Davidson

Boise State University Theses and Dissertations

In 1964, Paul Cohn showed that if F is a finitely-generated free group, and Q a field, then all ideals in the group ring Q[F] are free as Q[F]-modules. In particular, all finitely-generated submodules of free Q[F]-modules are free. In 1990, Cynthia Hog-Angeloni reproved this theorem using techniques from geometric group theory. Leaning on Hog-Angeloni's methods, we prove an analogous statement for crossed products D * F, with D a division ring.

With this result in hand, we prove that if G = HF, the semi-direct product …


Understanding Bioprospecting: Can Indigenous Populations Benefit From The Search For Pharmaceuticals In Areas Of High Biodiversity, Emily Schwindt May 2011

Understanding Bioprospecting: Can Indigenous Populations Benefit From The Search For Pharmaceuticals In Areas Of High Biodiversity, Emily Schwindt

Department of Environmental Studies: Undergraduate Student Theses

Bioprospecting is a controversial issue, and anthropologists and other scientists are quick to take sides. The idea of large corporations pumping money into conservation and development programs, while developing what could be the latest life-saving drug simply sounds too good to be true, and often times is. However, if all parties work together and proceed with caution, these benefits could become more than a fantasy. Looking at case studies from Costa Rica, India, South Africa and Panama this paper attempts to find patterns among successful bioprospecting agreements and note shortcomings and identify risks. This information will be used to suggest …


Improving Energy Sustainability In Pound Hall, Craig Adams May 2011

Improving Energy Sustainability In Pound Hall, Craig Adams

Department of Environmental Studies: Undergraduate Student Theses

This research project deals with improving energy sustainability in Pound Hall dormitory located on the University of Nebraska at Lincoln’s (UNL) city campus. An investigation on the current energy usage of Pound Hall showed that its energy rates worsened between the years of 2009 and 2010. These combined (electricity, steam, and water) energy rates were compared with those of the newly renovated Othmer Hall to emphasize the lack of sustainability in the older dormitory. In order to improve Pound Hall’s energy rates, an energy benefit analysis of implementing a green roof was performed. Having a green roof on this dormitory …


Extent Of Gully Erosion In An Agricultural Field In Northeastern Nebraska At Section 35 Township 29 North Range 1 West In Cedar County, Crystal Starkel May 2011

Extent Of Gully Erosion In An Agricultural Field In Northeastern Nebraska At Section 35 Township 29 North Range 1 West In Cedar County, Crystal Starkel

Department of Environmental Studies: Undergraduate Student Theses

My thesis project examined a gully within Section 35 Township 29 North Range 1 West. This gully has been noticed for five years and has grown substantially in those five years. The extent and causes of gully erosion were examined by considering the soil, the climate, the land management history, by measuring the gully physically, by using GIS, and by using an economic support tool was estimate soil loss. Appropriate recommendations were developed to reduce gully erosion.


Creating An Environmental Placed Based Education At Norris Elementary, Ben Kittrell May 2011

Creating An Environmental Placed Based Education At Norris Elementary, Ben Kittrell

Department of Environmental Studies: Undergraduate Student Theses

This study is focused on creating a place based education program. Place based education programs provide many benefits at the personal level with the students (PBEEC). The study was completed at Norris Elementary School where the students have access to the “Norris Forest” which is a planted forest with a walk way through the trees. Some of the trees are labeled for the students to identify and others are not. A graph of the unlabelled trees has been included for the students or the teachers to use.

This project incorporates activities that will engage the students in order to teach …


The Diffusion Of Environmental Literacy In An American Urban Community Through Children, Kelley Phillips May 2011

The Diffusion Of Environmental Literacy In An American Urban Community Through Children, Kelley Phillips

Department of Environmental Studies: Undergraduate Student Theses

Environmental literacy is a contentious issue in the United States of America because citizens feel it is forced upon them and interferes with our materialistic culture. Also, many Americans have limited access to green space and little time to devote to increasing their environmental mindset. This project documents a technique to introduce environmental literacy to American citizens by working with single communities in a common subset of American culture. Based on a model used by anthropologists in third world countries, the goal was to diffuse environmental literacy into a community by only instructing the children of that community in environmental …


21rst Century Educational Farmstead, Trevis Carmichael May 2011

21rst Century Educational Farmstead, Trevis Carmichael

Department of Environmental Studies: Undergraduate Student Theses

When Europeans began settling in the United States, farmsteads were built across the Great Plains. Out of necessity, these had to function in a self-sufficient manner; meaning the people had to produce their own food, use local materials, and be energy efficient for their transportation. Parents had to teach their children how to do all of the practical work it took to maintain their lives. This was the foundation that America was built upon. Having completed the first decade of the 21st century, the time seems right for a mental re-settlement that follows some of those same principles. Teaching our …


Ecotourism In Costa Rica: Environmental Impacts And Management, Emily Mckeone May 2011

Ecotourism In Costa Rica: Environmental Impacts And Management, Emily Mckeone

Department of Environmental Studies: Undergraduate Student Theses

Globally we are witnessing growing environmental destruction, particularly to the natural resource bases of underdeveloped countries. If ecotourism can generate profits for local economies, while protecting and conserving the natural resource base of that community, it could be a strong alternative for numerous countries. Evidence suggests that the ecotourism industry has been expanding at a rapid rate in recent decades (Dasenbrock 2002). It is important to understand the positive and negative ecological impacts of the industry as this rapid growth rate continues.

The main objective of this study is to highlight the strengths and weaknesses of the ecotourism industry in …


Analysis And Interpretation Of Factors Leading To Increased Aids Prevalence In Sub-Saharan Africa, William Kalhorn May 2011

Analysis And Interpretation Of Factors Leading To Increased Aids Prevalence In Sub-Saharan Africa, William Kalhorn

Department of Environmental Studies: Undergraduate Student Theses

My thesis research project focuses on the major factors that are contributing to the worst disease epidemic on the planet today. I have aimed to determine what may be some of the most important factors contributing to highly variable difference in HIV/AIDS prevalence rates are among the regions of East, West, and South Africa. The HIV/AIDS epidemic has been growing and expanding to new areas of the world since the first case arose in 1959 in what is now called Kinshasa, Congo (Avert, 2011). The AIDS/HIV epidemic is believed to have originated on the African continent, and this is where …


Educating Young Adults About Sustainable Development, Meghan Lewis May 2011

Educating Young Adults About Sustainable Development, Meghan Lewis

Department of Environmental Studies: Undergraduate Student Theses

This qualitative study on the types of environmental education on different age groups was conducted in Lincoln, Nebraska. The purpose of this thesis is to identify what age group and educational methods would be most effective to educate Lincoln citizens on the importance and benefits of sustainable development. Environmental education is an important aspect in implementation of new, environmentally friendly ideas.

Lincoln environmentalists are working to improve the city’s sustainability. Finding a way to consistently educate Lincoln residents on the importance and benefits of sustainable development will increase the public’s awareness of their efforts, leading to a greater interest in …


Designing A School Garden Space That Emphasizes Children's Wants And Uses Permaculture Design Methods, Mikhaela Mullins May 2011

Designing A School Garden Space That Emphasizes Children's Wants And Uses Permaculture Design Methods, Mikhaela Mullins

Department of Environmental Studies: Undergraduate Student Theses

A case study was organized at Saratoga Elementary school in Lincoln, Nebraska to obtain data on what children desire in a garden space. To collect this data a school garden space was constructed and an after school garden club was implemented. Students who participated in the after school garden club partook in the study by drawing their ideal garden. Elements that the subjects drew were identified and categorized into ‘highly desired’ and ‘somewhat desired’.

These elements were then incorporated into a proposed garden design plan for Saratoga. The proposal plan uses Permaculture design methods to emphasize sustainability.


Assessing Anglers Identification Of Common Fish Species Of Nebraska, Jason Reed May 2011

Assessing Anglers Identification Of Common Fish Species Of Nebraska, Jason Reed

Department of Environmental Studies: Undergraduate Student Theses

Creel surveys, also known as angler surveys, entail individual interviews with anglers. The interviews include a variety of questions pertaining to their fishing trip on that particular day. The interviewer asks the angler questions that include, but are not limited to what species they caught that day, the size of the fish, how many hours they spent fishing that day, what bait they were using, etc. If the angler does not know the species caught or misidentifies the species there is the potential for the recorded data to negatively impact management techniques that rely on the creel survey data. One …


Parks And Obesity In Rural And Urban Nebraska, Michaela S. Wolf May 2011

Parks And Obesity In Rural And Urban Nebraska, Michaela S. Wolf

Department of Environmental Studies: Undergraduate Student Theses

In order to better understand the role community design plays in obesity rates, this project studies a potential relationship between distance of parks from homes and obesity rates in four Nebraska counties. Park use may contribute to important health benefits, such as reducing risk of obesity by increasing physical activity levels. There are limitations to park use, such as crime rates and facility upkeep that are important to understand so that they might be managed and communities can reap greater benefits from their parks, including better fitness. This study examines park distance from homes as a potential limiting factor to …


Archaeoparasitology Of Chaco Canyon, Rachel Paseka May 2011

Archaeoparasitology Of Chaco Canyon, Rachel Paseka

Department of Environmental Studies: Undergraduate Student Theses

Ancient cultures of the Colorado Plateau have been a focus of archaeoparasitology since its inception, and a vast parasitological history is recorded in coprolites preserved in this arid region. The inhabitants of Chaco Canyon dominated Ancestral Puebloan culture between 1050 and 1120 AD and were responsible for the construction of great towns, road systems, and early agriculture. Analysis of the parasites preserved in fecal remains contributes to an increased knowledge of ancient Chacoan health and culture. Nineteen coprolites from four sites in Chaco Canyon were rehydrated and analyzed microscopically for parasite remains. Rhabditiform and filariform nematode larvae were found from …


Duffing-Van Der Pol-Type Nonlinear Oscillator System, Jing Cui May 2011

Duffing-Van Der Pol-Type Nonlinear Oscillator System, Jing Cui

Theses and Dissertations - UTB/UTPA

In this thesis, we are concerned with the nonlinear Duffing–van der Pol–type oscillator system by means of the Lie symmetry reduction method. This system has physical relevance as a simple model in certain flow-induced structural vibration problems, which includes the van der Pol oscillator and the damped Duffing oscillator etc as particular cases. By applying the Lie symmetry analysis, we find two nontrivial infinitesimal generators, and use them to construct canonical variables. Through the inverse analysis, some dynamical properties of the nonlinear system under certain parametric conditions are presented. Comparison with the existing results by the Prelle– Singer procedure is …


Distributed Semantic Web Data Management In Hbase And Mysql Cluster, Craig M. Franke May 2011

Distributed Semantic Web Data Management In Hbase And Mysql Cluster, Craig M. Franke

Theses and Dissertations - UTB/UTPA

Various computing and data resources on the Web are being enhanced with machine-interpretable semantic descriptions to facilitate better search, discovery and integration. This interconnected metadata constitutes the Semantic Web, whose volume can potentially grow the scale of the Web. Efficient management of Semantic Web data, expressed using the W3C's Resource Description Framework (RDF), is crucial for supporting new data-intensive, semantics-enabled applications. In this work, we study and compare two approaches to distributed RDF data management based on emerging cloud computing technologies and traditional relational database clustering technologies. In particular, we design distributed RDF data storage and querying schemes for HBase …


A Fully Automatic Segmentation Method For Breast Ultrasound Images, Juan Shan May 2011

A Fully Automatic Segmentation Method For Breast Ultrasound Images, Juan Shan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Breast cancer is the second leading cause of death of women worldwide. Accurate lesion boundary detection is important for breast cancer diagnosis. Since many crucial features for discriminating benign and malignant lesions are based on the contour, shape, and texture of the lesion, an accurate segmentation method is essential for a successful diagnosis. Ultrasound is an effective screening tool and primarily useful for differentiating benign and malignant lesions. However, due to inherent speckle noise and low contrast of breast ultrasound imaging, automatic lesion segmentation is still a challenging task.

This research focuses on developing a novel, effective, and fully automatic …


High Dynamic Range Imaging For The Detection Of Motion., Jeffrey Robert Hay May 2011

High Dynamic Range Imaging For The Detection Of Motion., Jeffrey Robert Hay

Electronic Theses and Dissertations

High dynamic range imaging involves imaging at a bit depth higher than the typical 8-12 bits offered by standard video equipment. We propose a method of imaging a scene at high dynamic range, 14+ bits, to detect motion correlated with changes in the measured optical signal. Features within a scene, namely edges, can be tracked through a time sequence and produce a modulation in light levels associated with the edge moving across a region being sampled by the detector. The modulation in the signal is analyzed and a model is proposed that allows for an absolute measurement of the displacement …


Exfoliated Graphite Nanoplatelet-Filled Impact Modified Polypropylene Nanocomposites, Alex Duguay May 2011

Exfoliated Graphite Nanoplatelet-Filled Impact Modified Polypropylene Nanocomposites, Alex Duguay

Electronic Theses and Dissertations

Exfoliated graphite nanoplatelets (xGnP)-filled polymer composites have demonstrated superior electrical, mechanical, physical and thermal properties and are becoming a major focus for both academic and industrial research and development (R&D) activities. The main objective of this study was to characterize the influence of xGnP particle diameter, filler loading and the addition of coupling agents on the mechanical, rheological and thermal properties of xGnP-filled impact modified polypropylene (IMPP) composites. IMPP is currently being used at the AEWC Advanced Structures and Composites Center in polymer impregnated (pre-preg) fiber reinforced polymer (FRP) tapes consisting of an IMPP matrix polymer and E-glass continuous fibers. …


Interannual Variability In American Lobster Settlement: Correlations With Sea Surface Temperature, Wind Stress And River Discharge, Mahima Jaini May 2011

Interannual Variability In American Lobster Settlement: Correlations With Sea Surface Temperature, Wind Stress And River Discharge, Mahima Jaini

Electronic Theses and Dissertations

Recruitment to benthic marine populations is fundamentally a biophysical problem. The American Lobster Settlement Index is an annual diver-based survey of the young-of-year American lobsters (Homarus americanus) found in inshore nurseries in New England, USA and Atlantic Canada at the end of the postlarval settlement season. The considerable interannual variability in the settlement index suggests that environmental factors play an important role in regulating planktonic larval supply and transport. In this study, I focused on the longest settlement time series from three oceanographically contrasting regions: Midcoast Maine, coastal Rhode Island and the lower Bay of Fundy. Sampling in these regions …


Assessment Of Conceptual Understanding Of Atomic Structure, Covalent Bonding, And Bond Energy, Alma Gonzales May 2011

Assessment Of Conceptual Understanding Of Atomic Structure, Covalent Bonding, And Bond Energy, Alma Gonzales

All Theses

This research work relied upon the importance of conceptual understanding to meaningful learning. Conceptual understanding is strongly influenced by students' prior knowledge (1). Many of these ideas pose strong barriers to deeper understanding and are called misconceptions since they are inconsistent or in conflict with generally accepted scientific facts (2). Thus, it is beneficial for instructors to initially elicit students' conceptual understanding in order to properly address student's misconceptions during the learning process. However, results are very dependent on the instrument used to elicit conceptual understanding (3). The most commonly used tools are summative assessments or achievement tests (4). They …


Nonparametric Methods In Varying Coefficient Models And Quantile Regression Models, Chinthaka Kuruwita May 2011

Nonparametric Methods In Varying Coefficient Models And Quantile Regression Models, Chinthaka Kuruwita

All Dissertations

This dissertation aims to address two problems in nonparametric regression models. An estimation issue in generalized varying coefficient models and a hypothesis testing issue in nonparametric quantile regression models is discussed.
We propose a new estimation method for generalized varying coefficient models where the link function is specified up to some smoothness conditions. Consistency and asymptotic normality of the estimated varying coefficient functions are established. Simulation results and a real data application demonstrate the usefulness of the new method.
A new approach for testing the equality of nonparametric quantile regression functions is also presented. Based on marked empirical processes, we …


Geochemical Controls On Mercury Methylation In Backwaters Of A Gulf Coastal Plain River System, Implications For Water Column Processes, Liam N. Schenk May 2011

Geochemical Controls On Mercury Methylation In Backwaters Of A Gulf Coastal Plain River System, Implications For Water Column Processes, Liam N. Schenk

Graduate Theses and Dissertations

The abundance and distribution of mercury and methyl mercury were investigated at three sites in the lower Ouachita River in the summer of 2010 in an effort to provide the first characterization of the extent of mercury contamination in this river system, and to investigate the potential for mercury methylation in the water column of backwaters off of the main channel. Results showed that filtered methyl mercury was positively correlated to dissolved organic carbon (r2=0.76) for water samples taken from the bottom 1 ft of the water column at three sites, suggesting the importance of dissolved organic carbon in mercury …


A Stochastic Model For Wind Turbine Power Quality Using A Levy Index Analysis Of Wind Velocity Data, Jonathan Blackledge, Eugene Coyle, Derek Kearney May 2011

A Stochastic Model For Wind Turbine Power Quality Using A Levy Index Analysis Of Wind Velocity Data, Jonathan Blackledge, Eugene Coyle, Derek Kearney

Conference papers

The power quality of a wind turbine is determined by many factors but time-dependent variation in the wind velocity are arguably the most important. After a brief review of the statistics of typical wind speed data, a non- Gaussian model for the wind velocity is introduced that is based on a Levy distribution. It is shown how this distribution can be used to derive a stochastic fractional diusion equation for the wind velocity as a function of time whose solution is characterised by the Levy index. A Levy index numerical analysis is then performed on wind velocity data for both …


An Analysis Of The Mortality Risks Associated With Heat And Heat Waves In Ireland, To Assist In Planning For Climate Change, Mathilde Pascal May 2011

An Analysis Of The Mortality Risks Associated With Heat And Heat Waves In Ireland, To Assist In Planning For Climate Change, Mathilde Pascal

Doctoral

Although extreme temperatures have not been identified as a major cause of mortality in Ireland, climate change calls for an evaluation of the past, present and future health risks associated with heat and heat waves. The health impacts of heat were investigated using mortality and temperature data for the period 1981-2003. Data were aggregated in urban areas (Dublin, Cork, Drogheda, Arklow, Dundalk, Galway, Limerick, Waterford and Wexford) and rural areas. Seven heat waves were identified between 1981 and 2003, corresponding to 254 excess deaths (197 in rural areas, and 57 in urban areas). A major episode was observed in rural …


A Contribution To The Vascular Flora Of The Sequatchie Valley Within Sequatchie County, Tennessee, John Richard Evans May 2011

A Contribution To The Vascular Flora Of The Sequatchie Valley Within Sequatchie County, Tennessee, John Richard Evans

Masters Theses and Doctoral Dissertations

The vascular flora of the Sequatchie Valley within Sequatchie County, Tennessee was studied for three growing seasons from 2008 through 2010. The Sequatchie Valley is located within the southeastern portion of the Cumberland Plateau and is generally considered to be part of the Cumberland Plateau Physiographic Province. Nevertheless, a number of geological and ecological factors distinguish the Sequatchie Valley from the elevated Cumberland Plateau, suggesting that the floristic composition of the valley may be different from the surrounding region. Although several previous floristic studies have been conducted on the plateau surface, very little attention has been given to the Sequatchie …


Testing The Utility Of The Consortium For The Barcoding Of Life's Two 'Agreed Upon' Plant Dna Barcodes, Matk And Rbcl, Iam Michael Cohen May 2011

Testing The Utility Of The Consortium For The Barcoding Of Life's Two 'Agreed Upon' Plant Dna Barcodes, Matk And Rbcl, Iam Michael Cohen

Masters Theses and Doctoral Dissertations

DNA barcoding is the use of short standardized regions of DNA to identify unknown specimens to species. Currently, the zoological community has agreed that cytochrome oxidase I subunit 1 (COI), a mitochondrial gene region, will serve as the barcode region for all animal taxa. Due to oftentimes complicated evolutionary histories of plants, the plant barcoding community has had a much harder time agreeing on a gene region or regions that should be used to barcode the various land plant lineages. This is in large part due to poor reproductive barriers, which allows for chloroplast sharing between closely related species. In …


Feasibility Study Of Carbon Offsets As A Source Of Revenue For A Land Trust Using The Climate Action Reserve's Avoided Conversion Protocol, Jennifer Marie Sexton May 2011

Feasibility Study Of Carbon Offsets As A Source Of Revenue For A Land Trust Using The Climate Action Reserve's Avoided Conversion Protocol, Jennifer Marie Sexton

Masters Theses and Doctoral Dissertations

In 2008, 279 million hectares of forest land contained 45,337 teragrams (Tg) of carbon. Changes in land use and forestry practices in 2008 resulted in a net carbon sequestration of 940.3 Tg of carbon dioxide equivalent, or 13.5% of total U.S. greenhouse gas emissions in 2008, making forests a net sink for carbon. With increasing development pressures, organizations such as land trusts, that protect forest land and prevent deforestation, are positioned to become key players in climate change mitigation. There are 21 land trusts in Tennessee protecting over 165,000 acres of land. One such land trust, the Tennessee River Gorge …


The Pt2 (1,0) Band Of System Vi In The Near Infrared By Intracavity Laser Absorption Spectroscopy, Leah O'Brien, James O'Brien May 2011

The Pt2 (1,0) Band Of System Vi In The Near Infrared By Intracavity Laser Absorption Spectroscopy, Leah O'Brien, James O'Brien

Chemistry & Biochemistry Faculty Works

Intracavity laser absorption spectroscopy has been used to record rotationally resolved electronic spectra of Pt2 in the near infrared. The metal dimers were created using a 50 mm-long, platinum-lined hollow cathode plasma discharge. The observed transition at 12 937 cm−1 is identified as the (1,0) band of System VI, with state symmetries Ω = 0 – X Ω = 0.


An Assessment Of Stable Hydrogen-Isotope Analysis Methods To Assign Geographic Origin To Migratory Red-Tailed Hawks (Buteo Jamaicensis), Carla Marie Ahlschwede May 2011

An Assessment Of Stable Hydrogen-Isotope Analysis Methods To Assign Geographic Origin To Migratory Red-Tailed Hawks (Buteo Jamaicensis), Carla Marie Ahlschwede

Department of Environmental Studies: Undergraduate Student Theses

Stable-hydrogen isotopes are becoming an increasingly popular method of studying migratory birds, though sample preparation methods may affect results. In this study I examined feathers from red-tailed hawks (Buteo jamaicensis) to determine the relationship between measure of δD due to inter-feather variation or drying methods, assessed the accuracy of results by using two birds of known-origin and estimated possible natal origins of migratory red-tailed hawks. Two feathers per individual were taken from 81 wild hawks caught at Hitchcock Nature Center near Crescent IA and from 2 rescued red-tailed hawks, Raptor Recovery Nebraska near Eagle, NE. 119 of the …