Digital Commons Network^™

Two-Photon Cross Section Enhancement Of Photochromic Compounds For Use In 3d Optical Data Storage, Gheorghe Luchita

Electronic Theses and Dissertations

Rewritable photochrome-based 3D optical data storage requires photochromic molecules with high two-photon absorption (2PA) cross sections. Currently, the low value of two-photon absorption cross sections of existing photochromes makes them unsuitable for practical application in 3D data storage. Worldwide attempts to increase the cross section of photochromic molecules by altering the chemical structure have yielded poor results. In this work, two ways to increase the two-photon absorption cross sections of photochromes were investigated. In the first method, partial success demonstrated by extending the conjugation of a photochromic molecule, a high two-photon absorption cross section of the closed form isomer and …

Addressing The Achievement Gap And Disproportionality Through The Use Of Culturally Responsive Teaching Practices, Angela Griner

Electronic Theses and Dissertations

Culturally responsive teaching practices in schools and classrooms have been shown to be an effective means of addressing the achievement gap, as well as the disproportionate representation of racially, culturally, ethnically, and linguistically diverse students in programs serving students with special needs. While there has been a recent influx in research discussing these issues, teachers and school staff lack clear examples and tools for best practices that will aid them in addressing the achievement gap and disproportionality effectively within their schools. Conducted in three phases, this research provides a framework for developing, implementing, and evaluating a culturally responsive tool for …

Self-Assembly And Photophysics Of Selected Organic Materials And Two-Photon Bioimaging With Profluorescent Nitroxides, Polyelectrolyte Nanoparticles, And Squaraine Probes, Hyo Yang Ahn

Electronic Theses and Dissertations

Two-photon absorption and upconverted fluorescence has been utilized in a variety of applications in pure science and engineering. Multiphoton-based techniques were used in this research in order to understand photophysical and chemical characteristics of several fluorescent dyes and to demonstrate some of their key applications. Two-photon fluorescence microscopy (2PFM) has become a powerful technique in bio-photonics for non-invasive imaging in the near-infrared (NIR) region (700~1000 nm) that often results in less photobleaching. In Chapter 1, there is a brief introduction to fluorescence, examples of fluorescence materials, and a discussion of the advantages of two-photon absorption. 2PFM imaging was utilized in …

Effects Of Deadline Conditions On Learners Of Different Procrastination Tendencies In An Online Course, Pin Wang

Electronic Theses and Dissertations

The purpose of this study was to investigate the effects of three deadline conditions (i.e., frequent-instructor-set-deadline condition, flexible-instructor-set-deadline condition, and self-imposed-deadline condition) on students of different academic procrastination levels (high, medium, and low) in terms of their perceived learning, academic performance, and course satisfaction in an online course. A 3 x 3 factorial quasi-experimental design was adopted for this study. One hundred and seventy three students from three classes of different majors voluntarily participated in the study with 50 students majoring in Agriculture, 61 in International Trading, and 62 in Food Manufacturing. The three classes were randomly assigned to three …

High Pressure And Micro-Spectroscopic Studies Of Single Living Erythrocytes And The Intraerythrocytic Multplication Cycle Of Plasmodium Falciparum, Silki Arora

Electronic Theses and Dissertations

A novel experimental approach for micro-absorption spectroscopy and high-pressure microscopy of single cells is developed and applied to the investigation of morphological, volume, and spectroscopic changes in healthy red blood cells (RBCs) and erythrocytes infected with the malaria parasite Plasmodium falciparum. Through real-time optical imaging of individual erythrocytes (size ~ 7[micrometer]) we determine the change in volume over the pressure range from 0.1 to 210 MPa. The lateral diameter of healthy RBCs decreases reversibly with pressure with an approximate slope of 0.015 [micrometer] / MPa. In infected cells, clear differences in the deformability and between the compression and decompression curves …

Characterization Of The Nonlinear Refractive Index Of Carbon Disulfide Over An Extended Spectral And Temporal Range, Marcus Seidel

Electronic Theses and Dissertations

The intensity dependent refractive index change of a medium is frequently described in terms of the product n₂ · I where n₂ is the nonlinear refractive index and I the light intensity. The nonlinear refractive index is often treated as constant which is a reasonable assumption if the light interacts only with bound electrons. In the case of carbon disulfide (CS₂) however, nuclear motions contribute to n₂. These motions occur on the sub picosecond time scale and thus become especially relevant for ultrashort laser pulses. The neat liquid CS₂ is studied because it exhibits a large nonlinear refractive index in …

An Approach To Improve The Failure Rate Model Of A Solid State Laser By Utalizing The Physics Of Failure Methodology, Omar L. Thompson

Electronic Theses and Dissertations

The ability to predict the failure rate of any military laser is very critical. In-field laser usage does not support the troubleshooting and repairing of a complex electro optical system. The only published laser failure rate model was last updated by the Department of Defense in 1975. Consequently, the failure rate predicted is inaccurate due to model deficiencies. This dissertation has developed a laser failure rate model for diode pumped lasers with improved failure rate prediction accuracy. The model has surpassed the capabilities of the Department of Defense model by the inclusion of key performance attributes that are currently not …

Ant Colony Optimization Approach For Stacking Configurations, Yijun Chen

Lingnan Theses

In data mining, classifiers are generated to predict the class labels of the instances. An ensemble is a decision making system which applies certain strategies to combine the predictions of different classifiers and generate a collective decision. Previous research has empirically and theoretically demonstrated that an ensemble classifier can be more accurate and stable than its component classifiers in most cases. Stacking is a well-known ensemble which adopts a two-level structure: the base-level classifiers to generate predictions and the meta-level classifier to make collective decisions. A consequential problem is: what learning algorithms should be used to generate the base-level and …

Evolutionary Developmental Biology And Intelligent Design, Scott F. Gilbert

Biology Faculty Works

No abstract provided.

Investigation Of Nanoceria-Modified Platinum-Gold Composite Electrodes For The Electrochemical Reduction Of Oxygen In Alkaline Media, Rahul Hegishte

Electronic Theses and Dissertations

Platinum-gold and nanoceria-modified platinum-gold electrodes were prepared on a platinum surface via electrochemical reduction of solutions of platinum and gold salts in the dispersion of nanoceria. The molar ratios of Pt and Au were varied in both PtAu and PtAu/CeO₂ electrodes while the total concentration of the metals was maintained at 2 x 10⁻³M and the concentration of nanoceria was maintained constant at 5 x 10⁻³M. The electrodes were characterized by their cyclic voltammetry curves in 0.5M sulfuric acid solution. The electrochemically active area of the electrodes was determined using the copper underpotential deposition method. The linear sweep voltammograms of …

The Application Of Two-Photon Absorbing Probes In Lysosomal, Zinc Ion Sensing And Folate Receptor-Targeted Bioimaging, Xuhua Wang

Electronic Theses and Dissertations

Two-photon fluorescence microscopy (2PFM) has become a powerful technique for bioimaging in non-invasive cancer diagnosis and also investigating the mechanization and original of a variety of diseases by tracking various biological processes. Because the fluorescence emission by two photon absorbing (2PA) is directly proportional to the square of the intensity of excitation light, this intrinsic property of 2PA provides 2PFM great advantages over traditional one-photon fluorescence microscopy (1PFM), including high 3D spatial localization, less photodamage and interference from biological tissue because of using longer wavelength excitation (700-1300 nm). However, most 2PA probes are hydrophobic and their photostabilities are questionable, severely …

The Unsuspected Pathway Of The Allosteric Transition In Hemoglobin, Stefan Fischer, Kenneth W. Olsen, Kwangho Nam, Martin Karplus

Chemistry: Faculty Publications and Other Works

Large conformational transitions play an essential role in the function of many proteins, but experiments do not provide the atomic details of the path followed in going from one end structure to the other. For the hemoglobin tetramer, the transition path between the unliganded (T) and tetraoxygenated (R) structures is not known, which limits our understanding of the cooperative mechanism in this classic allosteric system, where both tertiary and quaternary changes are involved. The conjugate peak refinement algorithm is used to compute an unbiased minimum energy path at atomic detail between the two end states. Although the results confirm some …

Distal Radioulnar Joint Biomechanics And Forearm Muscle Activity, Joseph Scott Bader

University of Kentucky Doctoral Dissertations

Optimal management of fractures, post-traumatic arthritis and instability of the distal radioulnar joint (DRUJ) requires an understanding of the forces existing across this joint as a function of the activities of daily living. However, such knowledge is currently incomplete. The goal of this research was to quantify the loads that occur at the DRUJ during forearm rotation and to determine the effect that individual muscles have on those loads.

Human and cadaver studies were used to analyze the shear (A-P), transverse (M-L) and resultant forces at the DRUJ and to determine the role that 15 individual muscles had on those …

Genetic And Physiological Contribution Of Adrenergic Cells In Heart Development, Kingsley Osuala

Electronic Theses and Dissertations

The adrenergic hormones norepinephrine (NE) and epinephrine (EPI) are essential for cardiovascular development as embryos lacking NE/EPI begin to die abruptly between embryonic days 10.5 and 11.5 due to apparent cardiac failure. The objective of this research aims to elucidate the mechanism of the embryonic fatality observed in the NE/EPI deficient mouse model. Here we utilized the dopamine β- hydroxylase knockout (Dbh-/-) mouse model, which lacks the gene and subsequent enzyme necessary for the conversion of dopamine to norepinephrine. Embryonic mouse hearts were extracted from Dbh+/+ (control) and Dbh-/- (experimental model) mice for mRNA transcript expression profiling. These studies were …

Low Noise And Low Repetition Rate Semiconductor-Based Mode-Locked Lasers, Dimitrios Mandridis

Electronic Theses and Dissertations

The topic of this dissertation is the development of low repetition rate and low noise semiconductor-based laser sources with a focus on linearly chirped pulse laser sources. In the past decade chirped optical pulses have found a plethora of applications such as photonic analogto-digital conversion, optical coherence tomography, laser ranging, etc. This dissertation analyzes the aforementioned applications of linearly chirped pulses and their technical requirements, as well as the performance of previously demonstrated chirped pulse laser sources. Moreover, the focus is shifted to a specific application of the linearly chirped pulses, timestretched photonic analog-to-digital conversion (TS ADC). The challenges of …

A Qualitative Case Study Of Novice Kenyan Primary School Teachers What Messages Transmitted By The Teacher Training Colleges Are Internalized And Applied?, Carol A. Kranz

Electronic Theses and Dissertations

The method of instruction and the formal curriculum within two Kenyan teacher training colleges were studied in order to discover which messages regarding pedagogical practice are internalized within novice Kenyan primary school teachers and then actualized within their classrooms. An educational connoisseurship approach was utilized to give descriptive, interpretive, evaluative, and thematic insight. Three data streams were collected through interview, observation, and design evaluation in order to establish structural corroboration and internal validity. The study found that the method of instruction by the teacher training college faculty was teacher-centered and utilized lower order cognitive methodology. Though the formal curriculum design …

Metal Blacks As Scattering Centers To Increase The Efficiency Of Thin Film Solar Cells, Deep R. Panjwani

Electronic Theses and Dissertations

Metal nano particles are investigated as scattering centers on front surface of thin-film solar cells to improve efficiency. The principle is that scattering, which is enhanced near the plasmon resonance frequency of the particle and depends on particle size, increases the effective optical path length of incident light, leading to more light absorption in active layer of thin film solar cell. The particular types of particles investigated here are known as "metal-black", well known as an IR absorber for bolometric infrared detectors. Gold-black was deposited on commercial thin-film solar cells using a thermal evaporator in a nitrogen ambient at pressures …

Middle School Literacy Coaches In Florida A Study Of The Relationships Among Experience, Coaching Activities, And Other Factors Related To Reading Achievement, Patricia A. Bowman

Electronic Theses and Dissertations

The focus of this research was to investigate and clarify the work lives of middle school literacy coaches in central Florida by studying their backgrounds and experiences before assuming the role of literacy coach. Additionally, the beliefs of literacy coaches on what factors influence reading achievement were examined. The responses of 44 participating middle school literacy coaches were used to investigate (a) the academic and professional experiences of each coach, (b) the percentage of time spent in 13 literacy coaching activities, and (c) the working factors related to student reading achievement as evidenced on the Florida Comprehensive Assessment Test. Data …

Fine-Scale Structures In Saturn's Rings Waves, Wakes And Ghosts, Kevin Baille

Electronic Theses and Dissertations

The Cassini mission provided wonderful tools to explore Saturn, its satellites and its rings system. The UVIS instrument allowed stellar occultation observations of structures in the rings with the best resolution available (around 10 meters depending on geometry and navigation), bringing our understanding of the physics of the rings to the next level. In particular, we have been able to observe, dissect, model and test the interactions between the satellites and the rings. We first looked at kilometer-wide structures generated by resonances with satellites orbiting outside the main rings. The observation of structures in the C ring and their association …

Towards Calibration Of Optical Flow Of Crowd Videos Using Observed Trajectories, Iman K. Elbadramany

Electronic Theses and Dissertations

The need exists for finding a quantitative method for validating crowd simulations. One approach is to use optical flow of videos of real crowds to obtain velocities that can be used for comparison to simulations. Optical flow, in turn, needs to be calibrated to be useful. It is essential to show that optical flow velocities obtained from crowd videos can be mapped into the spatially averaged velocities of the observed trajectories of crowd members, and to quantify the extent of the correlation of the results. This research investigates methods to uncover the best conditions for a good correlation between optical …

Program Completers' Perceptions Of Teacher Preparedness In Planning, Instruction, And Professionalism In Florida A Comparison Of District Alternative Programs, Traditional Programs, And Educator Preparatory Institutes, Lucile Heald Oldham

Electronic Theses and Dissertations

In this research, data collected by the Florida Department of Education (FLDOE) for 2006-2007 and 2007-2008 program completers of the following three Florida teacher preparation programs were compared: the Initial Teacher Preparation Programs (ITP) of approved colleges and universities, District Alternative Certification Programs (DACP), the Educator Preparatory Institutes (EPI). A factor analysis was performed to identify factors perceived by program completers as important to their preparedness to teach. The factors that most closely supported completers’ perceptions of Florida teacher preparation programs regarding successful preparation for the classroom were: Planning and Instruction; Assessment, Communication and Research; Professional Responsibility and Ethical Conduct; …

The Relative Recoverability Of Dna And Rna Profiles From Forensically Relevant Body Fluid Stains, Charly Parker

Electronic Theses and Dissertations

Biological material (fluids or tissues) whether from the victim or suspect is often collected as forensic evidence, and methods to obtain and analyze the DNA found in that material have been well established. The type of body fluid (i.e. blood, saliva, semen, vaginal secretions, and menstrual blood) from which the DNA originated is also of interest, and messenger RNA typing provides a specific and sensitive means of body fluid identification. In order for mRNA profiling to be utilized in routine forensic casework, RNA of sufficient quantity and quality must be obtained from biological fluid stains and the methods used for …

Effects On Teachers' Mathematics Content Knowledge Of A Professional Learning Community, Beverley Christmas Price

Electronic Theses and Dissertations

The purpose of this research was to study the implementation of a professional learning community comprised of one group of third-grade teachers in a Florida elementary school where the emphasis was on research-based practices in the teaching of mathematics. Investigated were the growth of teachers‟ content knowledge in mathematics, specifically in the areas of multiplication and division, and the effects of their professional learning within their classrooms. Specifically this study looked at whether or not the participation of a group of third grade teachers in a professional learning community PLC improved the mathematical content knowledge of the participants of the …

Price Discovery In The U.S. Bond Market Trading Strategies And The Cost Of Liquidity, Haimei Shao

Electronic Theses and Dissertations

The world bond market is nearly twice as large as the equity market. The goal of this dissertation is to study the dynamics of bond price. Among the liquidity risk, interest rate risk and default risk, this dissertation will focus on the liquidity risk and trading strategy. Under the mathematical frame of stochastic control, we model price setting in U.S. bond markets where dealers have multiple instruments to smooth inventory imbalances. The difficulty in obtaining the optimal trading strategy is that the optimal strategy and value function depend on each other, and the corresponding HJB equation is nonlinear. To solve …

Evaluation Of The Expectancy Challenge Alcohol Literacy Curriculum (Ecalc) For Reducing Alcohol Use Among High School Students, Janani Sivasithamparam

Electronic Theses and Dissertations

Alcohol use is the single most alarming behavior among youth in the United States. Adolescents especially are at risk for increases in heavy episodic drinking and drunkenness leading to alcohol-related problems such as academic failure, interpersonal violence, risky sexual behavior and death. In an effort to address this endemic issue, a number of alcohol use prevention programs have been developed and are currently implemented in the high school setting. Many of these programs, however, lack an empirical basis and have been unable to demonstrate significant reductions in alcohol use over time. The need for the development and dissemination of effective …

Variational Embedded Solitons, And Traveling Wavetrains Generated By Generalized Hopf Bifurcations, In Some Nlpde Systems, Todd Blanton Smith

Electronic Theses and Dissertations

In this Ph.D. thesis, we study regular and embedded solitons and generalized and degenerate Hopf bifurcations. These two areas of work are seperate and independent from each other. First, variational methods are employed to generate families of both regular and embedded solitary wave solutions for a generalized Pochhammer PDE and a generalized microstructure PDE that are currently of great interest. The technique for obtaining the embedded solitons incorporates several recent generalizations of the usual variational technique and is thus topical in itself. One unusual feature of the solitary waves derived here is that we are able to obtain them in …

An Investigation In Journal Writing And Cooperative Learning With 8th Grade Geometry Students In The Construction Of Proof, Paul Wojcik

Electronic Theses and Dissertations

This action research study summarizes the investigation of journal writing and cooperative grouping with 8th grade geometry students in the construction of proof. Students written responses to prompts in journals were analyzed over the course of twelve weeks. Case studies of four students were developed from the researchers’ three geometry classes. All four students in the study participated in an academic program called Pre International Baccalaureate Preparation. Standardized test scores and an attitude scale categorized the four students. The ATMAT survey (Appendix A) measured each student’s attitude toward mathematics. Writing prompts focused on the students’ perceptions of the group process …

The Study Of Three Different Layered Structures As Model Systems For Hydrogen Storage Materials, Muzaffer Tonguç Öztek

Electronic Theses and Dissertations

The strength and success of the hydrogen economy relies heavily on the storage of hydrogen. Storage systems in which hydrogen is sequestered in a solid material have been shown to be advantageous over storage of hydrogen as a liquid or compressed gas. Many different types of materials have been investigated, yet the desired capacity and uptake/release characteristics required for implementation have not been reached. In this work, porphyrin aggregates were investigated as a new type of material for hydrogen storage. The building blocks of the aggregates are porphyrin molecules that are planar and can assume a face to face arrangement …

College Science Teachers' Inquiry Beliefs And Practices In The Science Classroom, Janet L. Bisogno

Electronic Theses and Dissertations

The purpose of the study was to examine college science professors’ beliefs regarding the use of inquiry in the college science classroom, how these beliefs impacted their instructional choices and how these beliefs were enacted in the classroom. Additional questions were how teachers’ beliefs vary across institution types (community college, private, four year college, and large research institution), and how beliefs vary across disciplines (life sciences and physical sciences). A case study design was required for this study due to the complexity of the topic and different data sources needed to answer the fore stated research questions. These data sources …

The Relationship Between Principal Reported Instructional And Organizational Practices Of Title I Elementary Schools And Adequate Yearly Progress, Marsha Bur

Electronic Theses and Dissertations

This study examined the practices of Title I elementary school principals in the state of Florida for the school year 2009 - 2010. Elementary school principals in six Florida school districts responded to a survey to determine the extent of implementation of instructional and organizational practices identified by research to improve instruction and learning. The practices (sub-constructs) examined were identified as curriculum, instruction, assessment, educational agenda (vision, mission, beliefs, goals), leadership for school improvement, community building, and culture of continuous improvement. The results of this study indicated that participating Florida Title I principals believed that they were implementing effective instructional …