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I. Thermodynamics And Magnetism Of Cu2ocl2 Ii. Repairs To Microcalorimeter The "2"S Are Subscripts, And The Second 2 Is Preceded By A Lower Case L, Not A One, Thomas J. Parry Aug 2008

I. Thermodynamics And Magnetism Of Cu2ocl2 Ii. Repairs To Microcalorimeter The "2"S Are Subscripts, And The Second 2 Is Preceded By A Lower Case L, Not A One, Thomas J. Parry

Theses and Dissertations

Adiabatic calorimetry provides accurate and precise specific heat (Cp) data. From this data, thermodynamic functions may be calculated. Cu2OCl2, melanothallite, became of interest as part of a study of a particular thermochemical cycle. The experimental specific heat data and the calculated thermodynamic functions are reported here. Free energies of formation, calculated from the thermodynamic functions, suggest the particular cycle of interest with this compound as an intermediate is not feasible; uncertainty as to the accuracy of CuO and CuCl2 data used in the calculations indicate further study may be necessary. Upon collection of the specific heat data, an antiferromagnetic transition …

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Autonomous And Intelligent Radio Switching, Quiyi Duan Aug 2008

Autonomous And Intelligent Radio Switching, Quiyi Duan

Theses and Dissertations

With the proliferation of mobile applications and the abundance of wireless devices, it is increasingly common for devices to support multiple radios. When two devices are communicating they should choose the best available radio based on user preference and application requirements. This type of “radio switching” should happen automatically, so that the system optimizes performance dynamically. To achieve this objective, we design an Autonomous and Intelligent Radio Switching (AIRS) system to leverage the radio heterogeneity common in today's wireless devices. The AIRS system consists of three key components. First, we design a radio preference evaluation module to dynamically select the …

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Tooth Engagement Evaluation Of Involute Spline Couplings, Robert R. Robins Aug 2008

Tooth Engagement Evaluation Of Involute Spline Couplings, Robert R. Robins

Theses and Dissertations

Spline couplings are used in applications involving high torque; however, due to variations in teeth clearances, all teeth in spline couplings do not engage simultaneously, causing some of the teeth to carry a disproportionately large portion of the total load. Variations in tooth-to-tooth clearances mean the first pair of teeth to engage will carry more load and fail sooner. This has lead to an industry practice of designing splines around the criteria that only 25-50% of the teeth on a spline coupling will engage and carry the load, and the load is generally assumed to be uniformly distributed. This research …

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High-Level, Product Type-Specific Programmatic Operations For Streamlining Associative Computer-Aided Design, Nathan W. Scott Aug 2008

High-Level, Product Type-Specific Programmatic Operations For Streamlining Associative Computer-Aided Design, Nathan W. Scott

Theses and Dissertations

Research in the field of Computer Aided Design (CAD) has long focused on reducing the time and effort required of engineers to define three dimensional digital product models. Parametric, feature-based modeling with inter-part associativity allows complex assembly designs to be defined and re-defined while maintaining the vital part-to-part interface relationships. The top-down modeling method which uses assembly level control structures to drive child level geometry has proved valuable in maintaining these interfaces. Creating robust parametric models like these, however, is very time consuming especially since there can be hundreds of features and thousands of mathematical expressions to create. Even if …

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A Radical Conjugate Addition Approach To The Total Synthesis Of Celogentin C, Steven G. Capps Aug 2008

A Radical Conjugate Addition Approach To The Total Synthesis Of Celogentin C, Steven G. Capps

Theses and Dissertations

The synthesis of five chiral DBFOX (dibenzofuran-oxazoline) ligands with either aryl or benzyl substituents will be presented. The requisite amino alcohols were obtained with high enantioselectivity either commercially (DBFOX/Bn), via Sharpless asymmetric aminohydroxylation (DBFOX/Nap, DBFOX/t-BuPh, DBFOX/Pip), or via phase-transfer catalyzed asymmetric alkylation (DBFOX/MeNap). These ligands, complexed with Mg(NTf2)2, were used as Lewis acid promoters of enantioselective radical conjugate additions to α/β-unsaturated nitro-amides/esters. A summary of these results is presented and discussed. These findings led us to believe that our initial binding model between metal, ligand, and substrate was flawed. Thus, we figured that if we started with a functionality known …

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Optimization Constrained Cad Framework With Iso-Performing Design Generator, Kelly Eric Bowman Aug 2008

Optimization Constrained Cad Framework With Iso-Performing Design Generator, Kelly Eric Bowman

Theses and Dissertations

Design decisions have a large impact early in the design process. Optimization methods can help engineers improve their early decision making, however, design problems are often ill-posed for optimization at this early stage. This thesis develops engineering methods to use optimization during embodiment design, despite these difficulties. One common difficulty in designing mechanical systems is in handling the effects that design changes in one subsystem have on another. This is made more difficult in early engineering design, when design information is preliminary. Increased efforts have been made to use numerical optimization methods in early engineering design – because of the …

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A Microanalytical Approach To Understanding The Origin Of Cumulate Xenoliths From Mauna Kea, Hawaii, Megan Pickard Aug 2008

A Microanalytical Approach To Understanding The Origin Of Cumulate Xenoliths From Mauna Kea, Hawaii, Megan Pickard

Theses and Dissertations

Cumulate xenoliths erupted with alkalic hawaiite lavas from a postshield cinder cone on Mauna Kea, Hawaii include a variety of mafic and ultramafic rock types. Previous studies of major and trace element compositions of minerals in the xenoliths are interpreted to show transitional to alkalic magma parentages from the postshield stage, although any orthopyroxene-bearing xenoliths are considered to have tholeiitic parents. Major element compositions minerals were analyzed using the electron microprobe and trace element compositions of clinopyroxene grains were analyzed by laser ablation inductively coupled plasma mass spectrometry. In this study, major element compositions of clinopyroxene, olivine and plagioclase grains …

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On Autonomous Multi-Agent Control In Wilderness Search And Rescue: A Mixed Initiative Approach, Benjamin C. Hardin Aug 2008

On Autonomous Multi-Agent Control In Wilderness Search And Rescue: A Mixed Initiative Approach, Benjamin C. Hardin

Theses and Dissertations

Searching for lost people in a Wilderness Search and Rescue (WiSAR) scenario is a task that can benefit from large numbers of agents, some of whom may be robotic. These agents may have differing levels of autonomy, determined by the set of tasks they are performing. In addition, the level of autonomy that results in the best performance may change due to varying workload or other factors. Allowing a supervisor and a searcher to jointly decide the correct level of autonomy for a given situation (“mixed initiative”) results in better overall performance than giving an agent absolute control over their …

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Magmatic Sulfur And Chlorine Abundances At Stromboli, Italy And Their Role In The Formation Of Vesicle-Hosted Metal Alloys, Nichelle Lynn Baxter Aug 2008

Magmatic Sulfur And Chlorine Abundances At Stromboli, Italy And Their Role In The Formation Of Vesicle-Hosted Metal Alloys, Nichelle Lynn Baxter

Theses and Dissertations

Strand et al. (2002) discovered small metal alloy grains rich in Cu, Co, and Sn (maximum size 150 µm) in vesicles of lava from Kilauea Volcano. These alloys are also found in basaltic rocks of several Italian volcanoes. To better understand the origin of these metal-rich grains, bombs from Stromboli Volcano were examined. Two bomb types were collected from Stromboli: pumiceous bombs and scoriaceous bombs. Bulk rock trace element geochemistry indicates that there are no significant differences in Cu, Co, or Sn (the three major components of the metal alloys) between the pumiceous and scoriaceous bombs. Comparison of olivine melt …

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Pre-Eruptive Conditions Of The Oligocene Wah Wah Springs Tuff, Southeastern Great Basin Ignimbrite Province, Kurtus Steven Woolf Aug 2008

Pre-Eruptive Conditions Of The Oligocene Wah Wah Springs Tuff, Southeastern Great Basin Ignimbrite Province, Kurtus Steven Woolf

Theses and Dissertations

The Wah Wah Springs Tuff (30.0 Ma) is one of several very large volume ash-flow tuffs (>3200 km³ of erupted magma) that were emplaced near the peak of the flare-up of activity in the Great Basin ignimbrite province of western North America. It can be characterized as a "monotonous intermediate" ignimbrite because of its intermediate concentrations of silica (~63 to ~70 wt. %), apparent uniform chemical and mineralogical characteristics, and crystal-rich nature (32 ± 10 % phenocrysts on a dense rock basis). The major phase assemblage found throughout deposit is similar to other monotonous intermediates with a few exceptions …

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Regulators Of G-Protein Signaling, Rgs13 And Rgs16, Are Associated With Cxcl12-Mediated Cd4+ T Cell Migration, Lijin Xia Aug 2008

Regulators Of G-Protein Signaling, Rgs13 And Rgs16, Are Associated With Cxcl12-Mediated Cd4+ T Cell Migration, Lijin Xia

Theses and Dissertations

Chemokines are important chemical signals that guide lymphocyte movement within the immune system and promote the organization and functions of germinal centers (GCs) in the secondary lymphoid tissues. Previous studies have shown that GC T cells exhibit high expression of chemokine receptor 4, CXCR4, but that these cells are unable to migrate to the ligand for this receptor, the chemokine CXCL12. This “migratory paralysis” to CXCL12 was found to be correlated with the expression of two Regulators of G-protein Signaling, RGS13 and RGS16 in the GC T cells. The objective of my research was to determine whether RGS13 and RGS16 …

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Watertight Trimmed Nurbs, Thomas W. Sederberg, Xin Li, Hongwei Lin, Heather Ipson Aug 2008

Watertight Trimmed Nurbs, Thomas W. Sederberg, Xin Li, Hongwei Lin, Heather Ipson

Faculty Publications

This paper addresses the long-standing problem of the unavoidable gaps that arise when expressing the intersection of two NURBS surfaces using conventional trimmed-NURBS representation. The solution converts each trimmed NURBS into an untrimmed T-Spline, and then merges the untrimmed T-Splines into a single, watertight model. The solution enables watertight fillets of NURBS models, as well as arbitrary feature curves that do not have to follow isoparameter curves. The resulting T-Spline representation can be exported without error as a collection of NURBS surfaces.

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Spectroscopic Study Of Compressible Mobile Phase And Stationary Phase Behavior In Chromatography, Lawrence R. Baker Jul 2008

Spectroscopic Study Of Compressible Mobile Phase And Stationary Phase Behavior In Chromatography, Lawrence R. Baker

Theses and Dissertations

Raman spectroscopy, laser-induced fluorescence, and sum-frequency generation (SFG) spectroscopy are used to investigate the behavior of compressible mobile phases and stationary phases under a variety of chromatographic conditions. Efforts to understand and optimize separations employing compressible mobile phases have been limited by a lack of understanding of the mobile phase density gradient. Mobile phase compressibility leads to gradients in linear velocity and solute retention and affects separation speed and efficiency, especially in packed columns. This work describes on-column density measurement of CO2, a common carrier fluid for SFC and SGC, in packed capillary columns using Raman microspectroscopy. On-column detection by …

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The Development Of A Computational Model Of Thrombosis In Hemodialysis Catheters, Daniel J. Lattin Jul 2008

The Development Of A Computational Model Of Thrombosis In Hemodialysis Catheters, Daniel J. Lattin

Theses and Dissertations

Thromboembolism (TE) significantly limits the usefulness and safety of blood-contacting devices such as hemodialysis catheters. Computer simulation of TE can provide understanding of the process and can facilitate the design of more effective devices. Previous work conducted at BYU successfully modeled TE in a simple, two-dimensional flow cell design by adding quantitative TE code to a commercial computational fluid dynamics (CFD) package, Fluent. This two-dimensional model predicted thrombus initiation and growth and adjusted flow to accommodate thrombus geometries, but was limited by computational power and unsophisticated meshing techniques. To build upon this work, and take advantage of BYU's new supercomputing …

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Localized Coarsening Of Conforming All-Hexahedral Meshes, Adam C. Woodbury Jul 2008

Localized Coarsening Of Conforming All-Hexahedral Meshes, Adam C. Woodbury

Theses and Dissertations

Finite element mesh adaptation methods can be used to improve the efficiency and accuracy of solutions to computational modeling problems. For many finite element modeling applications, a conforming all-hexahedral mesh is preferred. When adapting a hexahedral mesh, localized modifications that preserve topologic conformity are often desired. Effective hexahedral refinement methods that satisfy these criteria have recently become available. However, due to hexahedral mesh topology constraints, little progress has been made in the area of hexahedral coarsening. This thesis presents a new method to locally coarsen conforming all-hexahedral meshes. The method works on both structured and unstructured meshes and is not …

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Changes In Kindergarteners' Writing Complexity When Using Story Elements, Lynne M. Watanabe Jul 2008

Changes In Kindergarteners' Writing Complexity When Using Story Elements, Lynne M. Watanabe

Theses and Dissertations

This study examined changes in kindergarteners' writing complexity after implementing writing instruction based on story elements (character, setting, problem, and solution). Writing samples from six students of three ability levels (i.e., beginning, intermediate, and advanced) were collected over a six-week period within a guided writing context. These samples included three types of texts (oral language, pictures, and written text)and were analyzed using two analytic rubrics specifically created for this study, one for writing development and the other for the inclusion of story elements. Findings from this study suggest that all students, regardless of ability level wrote in more complex ways …

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Assessing Multivariate Heritability Through Nonparametric Methods, Benjamin Alan Carper Jul 2008

Assessing Multivariate Heritability Through Nonparametric Methods, Benjamin Alan Carper

Theses and Dissertations

The similarities between generations of living subjects are often quantified by heritability. By distinguishing genotypic variation, or variation due to parental pairings, from phenotypic variation, or normal intraspecies variation, the heritability of traits can be estimated. Due to the multivariate nature of many traits, such as size and shape, computation of heritability can be difficult. Also, assessment of the variation of the heritability estimate is extremely difficult. This study uses nonparametric methods, namely the randomization test and the bootstrap, to obtain both a measure of the extremity of the observed heritability and an assessment of the uncertainty.

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Predicting Performance On Criterion-Referenced Reading Tests With Benchmark Assessments, Kaitlyn Nicole Dyson Jul 2008

Predicting Performance On Criterion-Referenced Reading Tests With Benchmark Assessments, Kaitlyn Nicole Dyson

Theses and Dissertations

The current research study investigates the predictive value of two frequently-used benchmark reading assessments: Developmental Reading Assessment (DRA) and the Dynamic Indicators of Basic Early Literacy Skills (DIBELS). With an increasing emphasis on high-stakes testing to measure reading proficiency, benchmark assessments may assist in predicting end-of-year performance on high-stakes testing. Utah's high-stakes measurement of end-of-year reading achievement is the English Language Arts Criterion-Referenced Test (ELA-CRT). A Utah urban school district provided data for students who completed the DRA, DIBELS, and ELA-CRT in the 2005-2006 school year. The primary purpose of the study was to determine the accuracy to which the …

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Theory And Estimation Of Acoustic Intensity And Energy Density, Derek C. Thomas Jul 2008

Theory And Estimation Of Acoustic Intensity And Energy Density, Derek C. Thomas

Theses and Dissertations

In order to facilitate the acquisition and accurate interpretation of intensity and energy density data in high-amplitude pressure fields, the expressions for intensity and energy density are examined to ascertain the impact of nonlinear processes on the standard expressions. Measurement techniques for estimating acoustic particle velocity are presented. The finite-difference method is developed in an alternate manner and presented along with bias and confidence estimates. Additionally, two new methods for estimating the local particle velocity are presented. These methods appears to eliminate the errors and bias associated with the finite-difference technique for certain cases.

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Enhancing Students' Science Content Knowledge Through Text Structure Awareness, Jamie Lynn Christensen Jul 2008

Enhancing Students' Science Content Knowledge Through Text Structure Awareness, Jamie Lynn Christensen

Theses and Dissertations

The purpose of this study was to examine the effects of teaching text structure as a tool to assist first grade students' understanding of science content in a unit of study on plants. A quantitative analysis was performed to reveal any difference in mean post-test scores between a control group and a treatment group. Results indicated that the treatment group students' science content knowledge was increased significantly more than students in the control group. Usage of specific text structure keywords did not increase. However, students did use synonyms of keywords. Recommendations for further research are discussed.

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Quantitative Uncertainty Of Chemical Plume Transport In Low Wind Speeds Using Measured Field Data And Stochastic Modeling, Veronica Elaine Wannberg Jul 2008

Quantitative Uncertainty Of Chemical Plume Transport In Low Wind Speeds Using Measured Field Data And Stochastic Modeling, Veronica Elaine Wannberg

Theses and Dissertations

Low wind speed conditions should be studied because these conditions can present risk, particularly for areas immediately surrounding the release point, where high concentrations can occur and not dissipate. The following research attempts to clarify the processes governing both the general and low wind speed cases by determining the accuracy and uncertainty of standard prediction methods for contaminant plume transport in low wind speed plume modeling. Multiple techniques were utilized to incorporate field measured data, previously gathered for a different purpose, to generate parameter distributions and ground-truth data that could be used in stochastic models for chemical plume prediction. These …

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Lyapunov Exponents And Invariant Manifold For Random Dynamical Systems In A Banach Space, Zeng Lian Jul 2008

Lyapunov Exponents And Invariant Manifold For Random Dynamical Systems In A Banach Space, Zeng Lian

Theses and Dissertations

We study the Lyapunov exponents and their associated invariant subspaces for infinite dimensional random dynamical systems in a Banach space, which are generated by, for example, stochastic or random partial differential equations. We prove a multiplicative ergodic theorem. Then, we use this theorem to establish the stable and unstable manifold theorem for nonuniformly hyperbolic random invariant sets.

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Ability Of Adv Measurements To Detect Turbulence Differences Between Angular And Rounded Gravel Beds Of Intermediate - Roughness Scale, Benjamin B. Haws Jul 2008

Ability Of Adv Measurements To Detect Turbulence Differences Between Angular And Rounded Gravel Beds Of Intermediate - Roughness Scale, Benjamin B. Haws

Theses and Dissertations

A set of laboratory experiments was carried out to distinguish flow characteristics(bed origin, shear velocity, turbulence intensity, turbulent kinetic energy) between beds of differing gravel angularity. Ten vertical profiles of velocity measurements were taken from angular and rounded fixed gravel beds with a 16 MHz micro acoustic Doppler velocimeter (ADV) sampling at 50 Hz. Both gravel beds had a bottom slope of 0.2% and were in the intermediate - roughness scale. Shear velocities were calculated using three common methods: St Venant, Reynolds stress, and Clauser. The Reynolds stress method resulted in the closest visual match to turbulence distributions proposed by …

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A Conceptual Analysis Of Technological Pedagogical Content Knowledge, Susan Marie Cox Jul 2008

A Conceptual Analysis Of Technological Pedagogical Content Knowledge, Susan Marie Cox

Theses and Dissertations

This dissertation reports the results of a conceptual analysis of the technological pedagogical content knowledge (TPACK) framework, particularly its component constructs of technological content knowledge (TCK), technological pedagogical knowledge (TPK), and TPACK (the central component of the framework listed earlier). First, a technical use analysis reveals how existing research has defined and exemplified the constructs. Next, interviews with leading TPACK researchers further refine the constructs. The dissertation then reports cases that illustrate each of the constructs and the boundaries between them. The conceptual analysis results in an elaborated model of the TPACK framework, focusing on the essential features of each …

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Compact Trench-Based Silicon-On-Insulator Rib Waveguide 90-Degree And 105-Degree Bend And Splitter Design, Jiguo Song Jul 2008

Compact Trench-Based Silicon-On-Insulator Rib Waveguide 90-Degree And 105-Degree Bend And Splitter Design, Jiguo Song

Theses and Dissertations

This thesis presents a theoretical and numerical investigation of silicon-on-insulator trench based passive optical components, bend and splitter, respectively. Compact 90 degree and 105 degree bend and splitter are designed with high index-contrast rib waveguide at wavelength 1550nm and serve as building blocks of splitting network in micro-cantilever biosensing application. The main characteristic of trench based bend and splitter structures is their miniature size and their low radiation loss due to the strong light confinement in high index-contrast systems. Thus large scale, high density optical integrated splitting network becomes possible with the associated advantages of compactness. With FDTD simulation, we …

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Effects Of Moisture On Combustion Of Live Wildland Forest Fuels, Brent M. Pickett Jul 2008

Effects Of Moisture On Combustion Of Live Wildland Forest Fuels, Brent M. Pickett

Theses and Dissertations

Current operational wildland fire models are based on numerous correlations from experiments performed on dry (dead) fuel beds. However, experience has shown distinct differences in burning behaviors between dry and moist (live) fuels. To better understand these fundamental differences, an experiment was designed to use a flat-flame burner to simulate a moving fire front which heated and ignited a stationary, individual fuel sample. Samples included various U.S. species from the California chaparral, the intermountain west, and the southeastern regions. Temperature, mass, and video images were recorded throughout each experimental run from which numerous data values were obtained such as time …

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Microkinetic Model Of Fischer-Tropsch Synthesis On Iron Catalysts, Uchenna Prince Paul Jul 2008

Microkinetic Model Of Fischer-Tropsch Synthesis On Iron Catalysts, Uchenna Prince Paul

Theses and Dissertations

Fischer-Tropsch synthesis (FTS), developed in the early 1900's, is defined as the catalytic conversion of H2 and CO to hydrocarbons and oxygenates with the production of H2O and CO2. Accurate microkinetic modeling can in principle provide insights into catalyst design and the role of promoters. This work focused on gaining an understanding of the chemistry of the kinetically relevant steps in FTS on Fe catalyst and developing a microkinetic model that describes FTS reaction kinetics. Stable Al2O3-supported/promoted (20% Fe, 1% K, 1% Pt) and unsupported Fe (99% Fe, 1% Al2O3) catalysts were prepared and characterized. Transient experiments including temperature programmed …

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Inverse Scattering Image Quality With Noisy Forward Data, Thomas J. Sorensen Jul 2008

Inverse Scattering Image Quality With Noisy Forward Data, Thomas J. Sorensen

Theses and Dissertations

Image quality metrics for several inverse scattering methods and algorithms are presented. Analytical estimates and numerical simulations provide a basis for poor image quality diagnostics. The limitations and noise behavior of reconstructed images are explored analytically and empirically using a contrast ratio. Theoretical contrast ratio estimates using the canonical PEC circular cylinder are derived. Empirical studies are conducted to confirm theoretical estimates and to provide examples of image quality vs SNR for more complex scatterer profiles. Regularized sampling is shown to be more noise sensitive than tomographic reconstructive methods.

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The Tropical Jacobian Of A Tropical Elliptic Curve Is S^1(Q), Darryl Gene Wade Jul 2008

The Tropical Jacobian Of A Tropical Elliptic Curve Is S^1(Q), Darryl Gene Wade

Theses and Dissertations

We establish consistent definitions for divisors, principal divisors, and Jacobians of a tropical elliptic curve and show that for a tropical elliptic cubic C , the associated Jacobian (or zero divisor class group) is the group S^1(Q).

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Blue Heron Goodbye, Holly Rose Hansen Jul 2008

Blue Heron Goodbye, Holly Rose Hansen

Theses and Dissertations

As is typical to the way I write essays, I did not understand the goal of this collection until I wrote the last essay, “Blue Heron Goodbye.” Up until that point I was calling the collection “Why We Need Bloodhounds.” This title felt sufficiently representative to me of the goal of the collection because in this essay, I use discussions canvassing the Bloodhounds' strong sense of smell to focus my discussion about the world of the heart. However, when I wrote “Blue Heron Goodbye,” I realized I wasn't only interested in the struggles of the human heart (a broad topic …

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