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Physical Sciences and Mathematics Commons™

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Electronic Theses and Dissertations

2009

The University of Maine

Articles 1 - 7 of 7

Full-Text Articles in Physical Sciences and Mathematics

Salinity And Stratification In The Gulf Of Maine: 2001-2008, Heather E. Deese-Riordan Dec 2009

Salinity And Stratification In The Gulf Of Maine: 2001-2008, Heather E. Deese-Riordan

Electronic Theses and Dissertations

The salinity and vertical density structure (stratification) of the Gulf of Maine strongly influence the physical and biological character of the region including: circulation and transport, vertical mixing, and primary productivity. Variability in salinity and stratification also provides insights into the character and timing of the oceanic waters entering the region, a key to predicting regional climate change. This thesis addresses outstanding questions related to variability in salinity and the relative role of salinity and temperature in creating stratification. Hourly observations from Ocean Observing System buoys throughout the Gulf provide the primary data source for this investigation. Analysis of estimated …

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Investigating Saxitoxin Resistance In Softshell Clams (Mya Arenaria): Patterns Of Inheritance And Improvements On Methodology For Tracking And Identification, Scott A. Hamilton Dec 2009

Investigating Saxitoxin Resistance In Softshell Clams (Mya Arenaria): Patterns Of Inheritance And Improvements On Methodology For Tracking And Identification, Scott A. Hamilton

Electronic Theses and Dissertations

Attempts to characterize and study the population dynamics of the softshell clam Mya arenaria in relation to a mutation which confers resistance to paralytic shellfish toxins are complicated by a lack of non-lethal genotyping techniques, reliable tagging methods and an understanding of the inheritance patterns of the marker. Presented here, is a straightforward and non-lethal technique for clam genotyping, a new method for the long term tagging of clams, and the offspring genotype frequencies from a number of pair matings between clams of known genotype. Hemolymph extracted from M. arenaria was used directly in a polymerase chain reaction (PCR) to …

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Biological Conversion Of Hemicellulose Extract Into Value-Added Fuels And Chemicals, Sara Lynn Walton Dec 2009

Biological Conversion Of Hemicellulose Extract Into Value-Added Fuels And Chemicals, Sara Lynn Walton

Electronic Theses and Dissertations

The research presented in this thesis describes the fermentation of hemicellulose extracts to produce ethanol and lactic acid. Hardwood hemicellulose extracts made at a variety of conditions using the green liquor and hot water extraction processes were characterized and then fermented by Escherichia coli K011 and Bacillus coagulans MXL-9. Hemicellulose extracts were found to contain a dilute amount of xylo-oligosaccharides and acetic acid as the major components, and many minor components including other organic acids, lignin-derived phenolics, and sugar degradation products. In order to generate ethanol economically, the fermentation must produce at least a 4% ethanol solution, which requires a …

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Room Temperature Tunable Energy Transfer Systems In Different Solvents, Zhonghua Guo Aug 2009

Room Temperature Tunable Energy Transfer Systems In Different Solvents, Zhonghua Guo

Electronic Theses and Dissertations

The focus of this thesis is on d8 and d10 metal-metal interactions, e.g. weak bonding in homometallic and heterometallic systems in liquid solutions, the tunability of luminescent energy due to the variation of metal-metal interaction strength in different solvents and different concentrations, as well as energy transfer from the luminescent energy tunable d8 and d10 metal ions clusters as donor ions to the lanthanide ions as acceptor ions at room temperature. First, energy transfer has been studied between dicyanoaurate(I) luminescent nanocluster donor ions and Eu3+ and Tb3+ acceptor ions in aqueous solutions. The emission …

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Geodynamics Of Terrane Accretion Within Southern Alaska, Benjamin Patrick Hooks Jan 2009

Geodynamics Of Terrane Accretion Within Southern Alaska, Benjamin Patrick Hooks

Electronic Theses and Dissertations

The subduction and accretion of an exotic terrane at the southern margin of Alaska is driving uplift of the St. Elias and Alaska Ranges, and is responsible for some of the largest strain releases in history. Here are presented results from numerical models conditioned by geological observations that reproduce the tectonic landscape, deformation, and strain patterns at macro- (1000-km) and meso- (<100 >km) scales. These models utilize completely coupled thermal and mechanical solutions that account for the development of heterogeneities to both the thermal and rheological structure of the lithosphere. Perturbation to the thermal structure related to flattening of the …

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Modeling Ice Streams, Aitbala Sargent Jan 2009

Modeling Ice Streams, Aitbala Sargent

Electronic Theses and Dissertations

Modeling glacier and ice sheet flow is a computationally challenging problem. The most challenging part in simulating ice sheet flow is modeling the fastest moving part of ice sheets, ice streams. In the first part of the thesis, we have constructed two numerical models of isothermal ice stream flow, a three-dimensional full-Stokes ice-sheet/ice-stream/ice-shelf model and a modified MacAyeal-Morland ice-stream/ice-shelf model. In the second part of the thesis, we studied the possibility of using SuperLU-DIST multiprocessor software package for solving the systems of linear equations generated by the model. The uniqueness of the modified MacAyeal-Morland model is in its inclusion of …

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Characterization Of Firn Microstructure Using Scanning Electron Microscopy: Implications For Physical Properties Measurements And Climate Reconstructions, Nicole Spaulding Jan 2009

Characterization Of Firn Microstructure Using Scanning Electron Microscopy: Implications For Physical Properties Measurements And Climate Reconstructions, Nicole Spaulding

Electronic Theses and Dissertations

Samples from 12 East Antarctic firn and ice cores were analyzed using scanning electron micrcoscopy (SEM) in order to first develop a technique for the accurate characterization of physical properties and then to investigate the relationship between the physical microstructure and chemical properties. Both physical properties, such as grain size and porosity, and chemical properties, such as major ion and trace element concentration, provide information about atmospheric temperature changes, impurity content, accumulation rate and deformation history; therefore the characterization of both types of properties is necessary. Further, knowledge of the relationship between the physical and chemical properties may increase our …

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