Digital Commons Network^™

The Process Of Making Meaning: The Interplay Between Teachers' Knowledge Of Mathematical Proofs And Their Classroom Practices, Megan Paddack

Doctoral Dissertations

The purpose of this study was to investigate and describe how middle school mathematics teachers make meaning of proofs and the process of proving in the context of their classroom practices. A framework of making meaning, created by the researcher, guided the data collection and analysis phases of the study. This framework describes the five central aspects of the process of making meaning: knowledge, beliefs, utilization of knowledge, interconnections of practice and knowledge, and making sense of past knowledge and current experiences. The utilization of a qualitative research methodology that combined ethnographic fieldwork and discourse analysis allowed the researcher to …

Flow Within The Engineering Pipeline: Motivation Of High -Achieving Students During The High School To College Transition, Nick Tatar

Doctoral Dissertations

Student motivation is often related to perceptions of the learning environment, making the transition from high school to college a critical period as students adjust to new learning environments. It is also a critical time for engineering programs as high-achieving students who drop out of engineering during this period are not likely to be replaced.

A web-based survey including nine scales assessing personal motivation, perceived classroom goal structures, and academic related beliefs and behaviors was administered to eighty-eight students who participated at two time points---the end of senior year in high school and the end of the first semester in …

Tracking Diet And Movement Of Atlantic Bluefin Tuna (Thunnus Thynnus) Using Carbon And Nitrogen Stable Isotopes, John Logan

Doctoral Dissertations

Atlantic bluefin tuna (ABFT; Thunnus thynnus) are important top predators in pelagic ecosystems. Understanding their diet and movements is necessary for proper management, but existing methods are costly and logistically challenging. Naturally occurring stable isotopes have been used to study diet and movement in many aquatic ecosystems and offer a novel approach for studying these large pelagic fishes.

Lipids, which have lower carbon isotope values than protein, can affect isotope analyses of bulk tissue. Both chemical and mathematical corrections were used to address lipid effects on ABFT and the prey. All chemical extraction methods altered nitrogen isotope values. Mathematical corrections …

Chemical Sensors Based On Swellable Polymer Microparticles And Molecular Imprinted Polymers, John Ong'any Osambo

Doctoral Dissertations

Swellable thermoresponsive and lightly cross-linked polymer microparticles were prepared for the development of chemical sensors for various target analytes. The swelling and shrinking of the polymer particles as a function of concentration of target analytes has been investigated using turbidity and fluorescence measurements at suitable pH values.

Chemical sensors that respond to transition metal ions such as Cu 2+, Ni2+, Zn2+, and Pb2+ were prepared by copolymerizing N-Isopropylacrylamide (NIPAAm) with ligands such as; 2,2'-acylamidodiacetic acid (AIDA), dibutyl-2,2'-(3 vinylphenylazanediyl) diacetate (DVPAA), N-((4'-methyl-2,2'-bipyridin-4yl)methyl)-N-propylacrylamide (NMPPAAm), and N,N-bis(pyridine-2-ylmethyl)prop-2-en-1-amine (NBPMPA). The microparticles were either labeled with 9-vinylanthracene (9-VA)/2-Naphthylmethacrylate (2-NMA), or fluorescein o-acrylate/methacryloxethyl thiocarbonyl rhodamine B …

Predicting Inclusive Teaching Using The Transtheoretical Model Of Behavior Change And The Theory Of Planned Behavior, Heather D. Hussey

Doctoral Dissertations

The diversity related materials in many university and college courses do not reflect the extent of diversity in society (Banks, 2002). Attempts to diversify curriculum have been made (Montgomery, 2001; Richards, Brown, & Forde, 2007), but further work is needed to prepare students to thrive in a culturally diverse society (Banks, 2002; Marshall, 2002). Research regarding faculty views toward diversity on campus and in the curriculum is limited (Brunner, 2006; Piland, Hess, & Piland, 2000; Wasonga & Piveral, 2004). Although a majority of faculty believe that a diversified institution and curriculum is positive, little research has examined the types of …

A Qualitative Study Of How Writing Is Used In Catholic Secondary Schools To Foster Students' Metacognitive Skill Development, Bonnie Jean Davis

Doctoral Dissertations

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Going Beyond Our Borders : Global Literature And Teacher Choice, Guy Andrew Scott Roberts

Doctoral Dissertations

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Triple Differential Measurements Of Single And Multiple Ionization Of Argon By Electron And Positron Impact, Jared M. Gavin

Doctoral Dissertations

"Singly, doubly, and triply differential measurements of single and multiple ionization of Ar by 1 keV positron and electron impact have been measured for projectile energy losses from 0 to 200 eV, scattering angles of 0° to ±5°, and electron emission angles from 45° to 135°. For single ionization, both projectiles show similar overall energy loss distributions but differ with respect to varying scattering angles. Triply differential yields for the electron emission demonstrate the binary and recoil features but the lobes are distorted because of extraction field effects plus variations in grid transmission and solid angle as a function of …

Seeking Refuge In Urban America : Refugee Students In An International Public High School In California, Nabila Massoumi

Doctoral Dissertations

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The Relationship Of Reading Methods And Learning Styles To Taiwanese 12th Grade Male Students' Reading Comprehension In English, Yachi Teng

Doctoral Dissertations

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In Search Of Music Equity In An Urban Middle School, John Calloway

Doctoral Dissertations

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Demystifying Success : Critical Reflections Of African-American California Community College Students About Factors Leading To Scholastic Success During The First Year, Robert Lee Snowden

Doctoral Dissertations

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A Critical Hermeneutic Approach To Understanding Experiences Of Selected Afghan-Muslim-American Leaders Post-9/11 In The Diverse Bay Area, Belal A. Kaifi

Doctoral Dissertations

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The Relationship Between Moving In Early Adolescence And Adolescents' First Employee-Type Jobs, Stuart J. Richardson

Doctoral Dissertations

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Organizational Change And Strategic Schooling For English Language Learners : A Case Study, Silvia Ramirez

Doctoral Dissertations

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Students', Teachers', And Parents' Perspectives Of An African Centered Program : Þle Omode, Tiffany S. Wright

Doctoral Dissertations

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Voices From The Forest : Leadership Revealed Through Care, Shared Understanding, And Imagination, Don Kraft

Doctoral Dissertations

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Student Perceptions Of The Higher Education Transfer Process From Two-Year To Four-Year Institutions : A Qualitative Study Viewed Through The Lenses Of Student Departure, Social Network, And Complexity Theories, Kevin Matthew Kelly

Doctoral Dissertations

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"So There We Were--" : The Stories Told By Chief Petty Officers In The United States Navy, Explored Through A Complexity Lens, Patricia Joanne Reily

Doctoral Dissertations

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A Study Of The Beneficial Role Of Thiol Antioxidant Supplementation In Various Forms Of Glutathione Deficiency, Linu Sara Abraham

Doctoral Dissertations

"Oxidative stress plays a major role in the pathology of numerous disorders afflicting humans, ranging from neurodegenerative diseases, to cancer, and heavy metal toxicity. Scientists are on the constant lookout for new and better antioxidants that have the ability to slow, if not stop the harmful degenerative effects of free radicals in oxidative stress related disorders. Both synthetic and naturally occurring compounds are being constantly screened for their antioxidant properties. This study attempted to evaluate the abilities of a thiol antioxidant, N-Acetylcysteine amide (NACA), to protect cells from the harmful effects of glutathione depletion in two different models of oxidative …

Anti Wetting Additives For Aluminosilicate Refractories In Molten Aluminum Contact Applications, Devdutt Pramod Shukla

Doctoral Dissertations

"Aluminosilicate based refractories are widely used in furnace installations for melting aluminum because they are inexpensive, readily available and generally exhibit the properties desired from a refractory material. However, they face severe corrosion and degradation issues due to the extremely reducing nature of molten aluminum alloys. Isothermal static cup testing is widely used as a tool to evaluate the performance of refractories against penetration by molten aluminum alloys. Various testing methods were reviewed and an upgraded static cup test was recommended. Commercially available aluminosilicate refractories were tested using this method and their results were studied in order to understand the …

Applications Of Sensor Arrays In Acoustic And Seismic Signal Processing, Peng Xie

Doctoral Dissertations

"This work investigates the applications of sensor arrays in the areas of acoustic and seismic signal processing. It comprises three papers.

The first paper explores the problem of blind source separation (BSS) for convolutive acoustic signals. It concentrates on the well known permutation and amplitude problems in frequency-domain BSS and proposes a new hybrid approach to solve them. This approach connects the separation processes across all frequency bins, and relies on a novel permutation control unit. This framework could greatly reduce computational load and improve separation performance. Synthesized and real-world experiments demonstrate its efficiency.

The second paper investigates a new …

Fundamentals Of Friction Stir Spot Welding, Harsha Badarinarayan

Doctoral Dissertations

"The recent spike in energy costs has been a major contributor to propel the use of light weight alloys in the transportation industry. In particular, the automotive industry sees benefit in using light weight alloys to increase fuel efficiency and enhance performance. In this context, light weight design by replacing steel with Al and/or Mg alloys have been considered as promising initiatives. The joining of structures made of light weight alloys is therefore very important and calls for more attention. Friction Stir Spot Welding (FSSW) is an evolving technique that offers several advantages over conventional joining processes.

The fundamentals aspects …

Systematic Functional And Object-Oriented Product Design Frameworks, Jen-Chi Wu

Doctoral Dissertations

"The existing co-design methods of mechatronic products focus on co-design of mechanical and electronic components or co-design of computer hardware and software components. There exist no effective co-design methods for mechanical, electronic and software components at the concept design stage. The research objective of this dissertation work is to develop more effective systematic product design approaches for co-design of mechatronic products. Three innovative functional and object-oriented integrated design frameworks and one virtual prototyping application, which leverages on these three design frameworks, have been developed for co-design of mechatronic products. The three frameworks are: I) Hierarchical Object-Oriented Functional Modeling Framework, 2) …

The Role Of Stochastic Resonance And Physical Constraints In The Evolution Of Foraging Strategy, Nathan Daniel Dees

Doctoral Dissertations

"This work represents a detailed study of the optimization of this process: foraging within a single, finite food patch for a limited amount of time. The work is an example of the computational algorithms of statistical physics being applied to the ecological field of foraging behavior. The analysis begins with an examination of the probability distributions observed in the movement parameters of the zooplankton, Daphnia. While foraging, these small aquatic organisms stochastically choose movement parameters with particular levels of variation, or noise, which are similar across several species. Here, related simulations consistently show that these noise levels may be adjusted …

F₂-Isoprostanes Study After Exposure To Selected Nanoparticles By Liquid Chromatography/Tandem Mass Spectrometry And Investigation Of Nanoparticles On The Cytotoxicity Effect Of Arsenic In Vitro, Xiaoqian Liu

Doctoral Dissertations

"Nanopartices as a new class of materials found their applications in industry, aerospace, clinical diagnosis and cancer therapy. Recently, the health effects of nanoparticles have caused people great concerns. This dissertation studies the mechanisms of nanoparticle cytotoxicity in human lung epithelial cells (A549). F₂-isoprostanes are novel reliable biomarkers for lipid peroxidation. In the first part of this work, total free F₂-isoprostanes were quantified by high performance liquid chromatography/mass spectrometry followed by the exposure of SiO₂ (15 nm), CeO₂ (20 nm), Fe₂O₃ (30 nm), and ZnO (70 nm) nanoparticles for 24 hours. For the first time, the results showed that F₂-isoprostanes …

Interference Effects Due To Projective-Target Nucleus Scattering In Single Ionization Of Molecular Hydrogen By 75 Kev Proton Impact, Jason S. Alexander

Doctoral Dissertations

"Doubly-differential cross-sections for the single ionization of molecular hydrogen by 75 keV proton impact have been measured as a function of the projectile scattering angle and energy loss and compared to available theoretical models. Interference structures are directly observed in the scattering angular dependence of the DDCS. The phase angle appears to be most sensitive to the projectile angle but not as sensitive to the electron energy, suggesting that the projectile - target nucleus interaction plays a central role in the interference. The large-angle structures disappear at electron speeds near the projectile speed. This may be due to a focusing …

Advanced Control Techniques For Doubly Fed Induction Generator-Based Wind Turbine Converters To Improve Low Voltage Ride-Through During System Imbalances, Murali M. Baggu

Doctoral Dissertations

A doubly-fed induction generator (DFIG) applied to wind power generation is under study for low voltage ride-through application during system disturbances. Conventional dq axis current control using voltage source converters for both the grid side and the rotor side of the DFIG are analyzed and simulated. DFIG operation is investigated under balanced and unbalanced system disturbances. A conventional d-axis and q-axis control applied to a voltage source converter (VSC) during a system imbalance exhibits oscillations in the stiff DC link voltage as well as in the real and reactive powers of the converter. Multiple advanced control methods are explored and …

Wind Power Applications To Groundwater Remediation, Ronald E. Gallagher

Doctoral Dissertations

"The use of renewable energy systems to power groundwater remediation systems seems like an inherently good idea because of potential cost savings and environmental benefits associated with reduced greenhouse gas emissions. Small wind turbine systems marketed for single residence applications may be the appropriate size for remediation systems, and such wind turbines are readily available at reasonable cost. Another benefit of using domestic wind turbine systems is that they are straightforward to install and operate with minimal training. One of the major drawbacks associated with using wind turbines at remediation sites is that site-specific wind velocity data is typically used …

Membrane Properties Of Intact Rock Cores Of Burlington Limestone, Jefferson Dolomite, Darrington Phyllite, And Low Permeability Concrete, Megan Hart

Doctoral Dissertations

"A number of laboratory studies have shown that clays exhibit membrane properties. However, little research has been performed on lithologies outside of pure clays. Recently, research focusing on mixed sand and clay membrane properties for engineering applications was performed. Still, literature only suggests the possibilities of membrane properties, osmotic or reverse-osmotic, associated with other naturally occurring 'tight' rock types. Therefore, the objectives of this research was to perform a series of hyperfiltration experiments using actual rock discs of Quarry Ridge Jefferson Dolomite, Darrington Phyllite, Lower Burlington Limestone, and low permeability concrete to determine if tight lithologies can function as membranes"--Abstract, …