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Title: THE EFFECTIVENESS OF TEACHING METHODS DESIGNED TO IMPROVE STUDENT ENGAGEMENT AND RETENTION OF PHYSICS SUBJECT MATTER FOR BOTH SCIENCE AND NON-SCIENCE MAJORS.
Creator: Maronde, Dan, Efthimiou, Costas, University of Central Florida
Abstract / Description: The necessity of students' engagement with the subject matter for successful learning is well-documented in education research in general, and in physics education research in particular. This study examines the merits of two different programs designed to improve student learning through enhanced student engagement with the material. The target populations of the two programs are different: One is the group of students taking a physical science class as part of the general curriculum...
Show moreThe necessity of students' engagement with the subject matter for successful learning is well-documented in education research in general, and in physics education research in particular. This study examines the merits of two different programs designed to improve student learning through enhanced student engagement with the material. The target populations of the two programs are different: One is the group of students taking a physical science class as part of the general curriculum required of non-science, non-engineering majors; the other is the group of students, mostly in engineering disciplines, who must take the calculus-based introductory physics sequence as part of their majors' core curriculum. The physical science class is required for non-science majors due to the importance of having a science-literate public. To improve this group's engagement with the subject matter, Physics in Films approaches the subject in the context of scenes taken from popular Hollywood films. Students' learning in the class is evaluated by comparison between performance on pre- and post-tests. The students are also polled on their confidence in their answers on both tests, as an improved belief in their own knowledge is one of the goals of the class. For the calculus-based physics group, a large issue is retention within the major. Many students change to non-science majors before the completion of their degree. An improved understanding of the material in the introductory physics sequence should help alleviate this problem. The Physics Suite is a multi-part introductory physics curriculum based on physics education research. It has been shown to be effective in several studies when used in its entirety. Here, portions of the curriculum have been used in select sections of the introductory physics classes. Their effectiveness, both individually and in conjunction, is studied. Students' mastery of concepts is evaluated using pre- and post-tests, and effects on class performance and retention within the major are examined. Input from both groups of students in the study was obtained through interviews and surveys.
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Date Issued: 2011
Identifier: CFE0003742, ucf:48793
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0003742

Title: SYMMETRY IN THE DISSOCIATIVE RECOMBINATION OF POLYATOMIC IONS AND IN ULTRA-COLD FEW BODY COLLISIONS.
Creator: Douguet, Nicolas, Kokoouline, Viatcheslav, University of Central Florida
Abstract / Description: We discuss the role of symmetries in the dissociative recombinations (DR) of three polyatomic ions, namely the linear HCO+ (formyl) ion and the two highly symmetric H3+ and H3O+ (hydronium) molecular ions. Regarding the HCO+ ion, we apply a quantum mechanical treatment using the Multi-channel Quantum Defect Theory (MQDT) formalism to describe the ion-electron scattering process. Our study takes into account the Renner-Teller effect in order to model the non Born-Oppenheimer vibronic coupling...
Show moreWe discuss the role of symmetries in the dissociative recombinations (DR) of three polyatomic ions, namely the linear HCO+ (formyl) ion and the two highly symmetric H3+ and H3O+ (hydronium) molecular ions. Regarding the HCO+ ion, we apply a quantum mechanical treatment using the Multi-channel Quantum Defect Theory (MQDT) formalism to describe the ion-electron scattering process. Our study takes into account the Renner-Teller effect in order to model the non Born-Oppenheimer vibronic coupling in linear polyatomic ions. The coupling has shown to represent the main mechanism responsible for electronic capturing in highly excited Rydberg states associated with excited vibrational levels of the ionic core. We consider all internal degrees of freedom of HCO+ and obtain the dissociative cross section as a function of the incident electron kinetic energy. We have also improved the theoretical approach by including the large permanent dipole moment of HCO+ using a generalization of the MQDT formalism. To our knowledge, this is the first time the permanent dipole moment of an ion is included in a DR study. The obtained results are in good agreement with experimental data. W also study the DR of H3+ and H3O+ symmetric ions using a simplified theoretical treatment, which focuses on the key ingredient of the DR process, the electron capture in the first excited degenerate vibrational normal mode of the ions through non Born-Oppenheimer Jahn-Teller coupling. For both ions the obtained cross sections are in very good agreement with the available experimental data. Moreover, in the case of H3+, the results reproduce previous calculations from two independent theoretical studies. Finally, we investigate the role of symmetries in few body ultra-cold collisions by considering both three and four identical atoms systems. We derive allowed rearrangements of different fragments of the system, satisfying the complete symmetry of the molecular Hamiltonian. For that purpose we establish a correspondence between constants of motion of the system in different large-distance configurations and irreducible representations of the total symmetry group. Selection rules (forbidden transitions) and allowed states, which depend on the fermionic or bosonic nature of the atoms, can be derived from these results.
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Date Issued: 2010
Identifier: CFE0003552, ucf:48896
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0003552

Title: AN ANALYSIS OF PREDICTORS OF ENROLLMENT AND SUCCESSFUL ACHIEVEMENT FOR GIRLS IN HIGH SCHOOL ADVANCED PLACEMENT PHYSICS.
Creator: DePalma, Darlene, Boote, David, University of Central Florida
Abstract / Description: A problem within science education in the United States persists. U.S students rank lower in science than most other students from participating countries on international tests of achievement (National Center for Education Statistics, 2003). In addition, U.S. students overall enrollment rate in high school Advanced Placement (AP) physics is still low compared to other academic domains, especially for females. This problem is the background for the purpose of this study. This investigation...
Show moreA problem within science education in the United States persists. U.S students rank lower in science than most other students from participating countries on international tests of achievement (National Center for Education Statistics, 2003). In addition, U.S. students overall enrollment rate in high school Advanced Placement (AP) physics is still low compared to other academic domains, especially for females. This problem is the background for the purpose of this study. This investigation examined cognitive and motivational variables thought to play a part in the under-representation of females in AP physics. Cognitive variables consisted of mathematics, reading, and science knowledge, as measured by scores on the 10th and 11th grade Florida Comprehensive Assessment Tests (FCAT). The motivational factors of attitude, stereotypical views toward science, self-efficacy, and epistemological beliefs were measured by a questionnaire developed with question taken from previously proven reliable and valid instruments. A general survey regarding participation in extracurricular activities was also included. The sample included 12th grade students from two high schools located in Seminole County, Florida. Of the 106 participants, 20 girls and 27 boys were enrolled in AP physics, and 39 girls and 20 boys were enrolled in other elective science courses. Differences between males and females enrolled in AP physics were examined, as well as differences between females enrolled in AP physics and females that chose not to participate in AP physics, in order to determine predictors that apply exclusively to female enrollment in high school AP physics and predictors of an anticipated science related college major. Data were first analyzed by Exploratory Factor Analysis, followed by Analysis of Variance (ANOVA), independent t-tests, univariate analysis, and logistic regression analysis. One overall theme that emerged from this research was findings that refute the ideas that females have lower achievement scores, lower attitude, lower self-efficacy, and more stereotypical views regarding science than males. Secondly, the only significant differences found between males and females enrolled in AP physics were for stereotypical views toward science and one factor from the epistemological views questions, both of which favored females. Although the non AP boys significantly outscored non AP girls on science FCAT scores, the only other significant differences found between these groups of students were related to attitude, with the girls scoring higher than the boys on both counts. There were significant differences found for numerous variables between AP and non AP females, however, most of the same differences were found between the two ability groups of male students as well. This leads to the conclusion that these factors certainly play an important role in AP physics enrollment for both genders. But the few significant differences found exclusively between the two female ability groups; reading ability, stereotypical views toward science, and the epistemological beliefs regarding branches of physics being related by common principles and aspects of physics need to be inferred instead of directly measured, may play a more important role in increasing enrollment numbers of females.
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Date Issued: 2008
Identifier: CFE0002121, ucf:47533
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002121

Title: EVALUATING THE QUALITY OF PHYSICAL EDUCATION PROGRAMS PROVIDED BY STATE DEPARTMENT OF EDUCATION WEBSITES AND THE RELATIONSHIPS BETWEEN ADOLESCENT OBESITY AND SEDENTARY PREVALENCE.
Creator: McWilliams, Payton C, Valdes, Anna, University of Central Florida
Abstract / Description: This research seeks to determine the relationships between the quality of physical education (PE) programs provided by state departments of education (DOE), obesity rates, and sedentary behaviors described as physical inactivity in adolescents ages 10-17 years old. A modified rubric based on the "Let's Move Active Schools Assessment" was created and used to quantitatively and qualitatively evaluate the PE programs and physical activity (PA) opportunities provided by websites of the state's...
Show moreThis research seeks to determine the relationships between the quality of physical education (PE) programs provided by state departments of education (DOE), obesity rates, and sedentary behaviors described as physical inactivity in adolescents ages 10-17 years old. A modified rubric based on the "Let's Move Active Schools Assessment" was created and used to quantitatively and qualitatively evaluate the PE programs and physical activity (PA) opportunities provided by websites of the state's DOE. A total of fourteen states were chosen to be assessed due to having either the highest or lowest obesity or physical inactivity rates. It was believed that the states with the highest obesity prevalence would have the highest inactivity and the lowest quality PE programs, and that those with lowest obesity prevalence would have lowest physical inactivity and high quality PE programs. After assessing the chosen states, no correlation was found between the quality of PE program as determined from the created rubric and the obesity or sedentary behavior rates of the state. The highest grade of all states assessed was 23 out of 27 with the lowest score being 7. The average scores of the states with the highest obesity was greater than the average for those states with the lowest inactivity, indicating that the quality of PE programs as provided by the DOE are not exclusively related to obesity and physical inactivity prevalence. Other determining factors such as nutrition, state funding, local policies, and societal factors may be more involved in the health of children than what is popularly believed. The data show that efforts are being made to decrease obesity throughout schools and the departments of education, however the efficiency of such efforts to increase physical activity and health are low. While states may post plans for PE and create standards for teaching, local levels of education are not required to enforce the policies or teach the curriculum suggested. Including students with special conditions and providing physical activities outside the school building is also lacking although it may seem like measures are being taken to provide such opportunities. More evaluations must be completed to get a stronger understanding of how to fix inadequate physical education and activity programs provided by the states' DOEs. Reviewing each DOE efforts as well as that of the community and individual school districts would help gain insight into where roadblocks reside and how to overcome destructive policies to offer better physical activity and education to children.
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Date Issued: 2017
Identifier: CFH2000221, ucf:45982
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH2000221

Title: Characterization and Application of Isolated Attosecond Pulses.
Creator: Chini, Michael, Chang, Zenghu, Saha, Haripada, Chow, Lee, Schulzgen, Axel, University of Central Florida
Abstract / Description: Tracking and controlling the dynamic evolution of matter under the influence of external fields is among the most fundamental goals of physics. In the microcosm, the motion of electrons follows the laws of quantum mechanics and evolves on the timescale set by the atomic unit of time, 24 attoseconds. While only a few time-dependent quantum mechanical systems can be solved theoretically, recent advances in the generation, characterization, and application of isolated attosecond pulses and few...
Show moreTracking and controlling the dynamic evolution of matter under the influence of external fields is among the most fundamental goals of physics. In the microcosm, the motion of electrons follows the laws of quantum mechanics and evolves on the timescale set by the atomic unit of time, 24 attoseconds. While only a few time-dependent quantum mechanical systems can be solved theoretically, recent advances in the generation, characterization, and application of isolated attosecond pulses and few-cycle femtosecond lasers have given experimentalists the necessary tools for dynamic measurements on these systems. However, pioneering studies in attosecond science have so far been limited to the measurement of free electron dynamics, which can in most cases be described approximately using classical mechanics. Novel tools and techniques for studying bound states of matter are therefore desired to test the available theoretical models and to enrich our understanding of the quantum world on as-yet unprecedented timescales.In this work, attosecond transient absorption spectroscopy with ultrabroadband attosecond pulses is presented as a technique for direct measurement of electron dynamics in quantum systems, demonstrating for the first time that the attosecond transient absorption technique allows for state-resolved and simultaneous measurement of bound and continuum state dynamics. The helium atom is the primary target of the presented studies, owing to its accessibility to theoretical modeling with both ab initio simulations and to model systems with reduced dimensionality. In these studies, ultrafast dynamics (-) on timescales shorter than the laser cycle (-) are observed in prototypical quantum mechanical processes such as the AC Stark and ponderomotive energy level shifts, Rabi oscillations and electromagnetically-induced absorption and transparency, and two-color multi-photon absorption to (")dark(") states of the atom. These features are observed in both bound states and quasi-bound autoionizing states of the atom. Furthermore, dynamic interference oscillations, corresponding to quantum path interferences involving bound and free electronic states of the atom, are observed for the first time in an optical measurement. These first experiments demonstrate the applicability of attosecond transient absorption spectroscopy with ultrabroadband attosecond pulses to the study and control of electron dynamics in quantum mechanical systems with high fidelity and state selectivity. The technique is therefore ideally suited for the study of charge transfer and collective electron motion in more complex systems.The transient absorption studies on atomic bound states require ultrabroadband attosecond pulses ? attosecond pulses with large spectral bandwidth compared to their central frequency. This is due to the fact that the bound states in which we are interested lie only 15-25 eV above the ground state, so the central frequency of the pulse should lie in this range. On the other hand, the bandwidth needed to generate an isolated 100 as pulse exceeds 18 eV (-) comparable to or even larger than the central frequency. However, current methods for characterizing attosecond pulses require that the attosecond pulse spectrum bandwidth is small compared to its central frequency, known as the central momentum approximation. We therefore explore the limits of attosecond pulse characterization using the current technology and propose a novel method for characterizing ultrabroadband attosecond pules, which we term PROOF (phase retrieval by omega oscillation filtering). We demonstrate the PROOF technique with both simulated and experimental data, culminating in the characterization of a world-record-breaking 67 as pulse.
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Date Issued: 2012
Identifier: CFE0004781, ucf:49802
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004781

Title: Integration of Fundamental Research and CER: The Role of Authenticity in Developing Views on the Nature of Teaching, Learning, and Doing Science.
Creator: Donnelly, Julie, Hernandez, Florencio, Del Barco, Enrique, Saitta, Erin, Yestrebsky, Cherie, Underwood, Sonia, University of Central Florida
Abstract / Description: This dissertation is an integration of fundamental research and chemical education. It begins with two nonlinear spectroscopic studies of compounds important to the study of brain chemistry. In Chapter 2, we present a novel method using quantum mechanics for modelling ligand docking and the potential of nonlinear circular dichroism for elucidating the mechanism of cannabinoids docking to their receptor, a contribution to studies of varying psychological effects of cannabinoids. Considering...
Show moreThis dissertation is an integration of fundamental research and chemical education. It begins with two nonlinear spectroscopic studies of compounds important to the study of brain chemistry. In Chapter 2, we present a novel method using quantum mechanics for modelling ligand docking and the potential of nonlinear circular dichroism for elucidating the mechanism of cannabinoids docking to their receptor, a contribution to studies of varying psychological effects of cannabinoids. Considering existent challenges with measuring this phenomenon, in Chapter 3, we evaluate two-photon absorption properties of Thioflavin T (ThT) in varying glycerol/water content solutions and discuss the enhancement of nonlinear absorption due to small micelle formation. Our results represent the potential to enhance the applications of ThT for imaging Amyloid beta plaques in vitro and ex vivo and its potential application in vivo. Next, we consider the benefits of incorporating modern research into the undergraduate curriculum. In Chapter 4, we describe the integration of nonlinear optics into the physical chemistry laboratory in a course-based undergraduate research experience and the effects on student learning and perceptions. In Chapter 5, we expand our impact to secondary students by describing the development and assessment of the Orlando Chemistry Training, Enrichment, and Tutoring (OCTET) camp and its success in conveying chemistry concepts and inspiring students to pursue chemistry. In Chapter 6, we combine the successes of the previous two studies and incorporate a research component into OCTET. We study the effect on participants' views about science and show the impact on their practical knowledge about doing science. Finally, in Chapter 6, we extend the implementation of authentic learning to the classroom, present the implementation of active learning in physical chemistry, and describe students' perceptions. The results presented in this dissertation demonstrate successful integration of fundamental research into education and the powerful impact on all parties.
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Date Issued: 2018
Identifier: CFE0006997, ucf:51620
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006997

Title: Dynamical Invariants and the Fluid Impulse in Plasma Models.
Creator: Michalak, Martin, Shivamoggi, Bhimsen, Mohapatra, Ram, Brennan, Joseph, Eastes, Richard, University of Central Florida
Abstract / Description: Much progress has been made in understanding of plasmas through the use of the MHD equations and newer models such as Hall MHD and electron MHD. As with most equations of fluid behavior, these equations are nonlinear, and no general solutions can be found. The use of invariant structures allows limited predictions of fluid behavior without requiring a full solution of the underlying equations. The use of gauge transformation can allow the creation of new invariants, while differential...
Show moreMuch progress has been made in understanding of plasmas through the use of the MHD equations and newer models such as Hall MHD and electron MHD. As with most equations of fluid behavior, these equations are nonlinear, and no general solutions can be found. The use of invariant structures allows limited predictions of fluid behavior without requiring a full solution of the underlying equations. The use of gauge transformation can allow the creation of new invariants, while differential geometry offers useful tools for constructing additional invariants from those that are already known. Using these techniques, new geometric, integral and topological invariants are constructed for Hall and electron MHD models. Both compressible and incompressible models are considered, where applicable. An application of topological invariants to magnetic reconnection is provided. Finally, a particular geometric invariant, which can be interpreted as the fluid impulse density, is studied in greater detail, its nature and invariance in plasma models is demonstrated, and its behavior is predicted in particular geometries under different models.
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Date Issued: 2013
Identifier: CFE0005382, ucf:50442
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005382

Title: WHAT IS APPEALING?:SEX AND RACIAL DIFFERENCES IN PERCEPTIONS OF THE PHYSICAL ATTRACTIVENESS OF WOMEN.
Creator: Sewell, Rachel, Donley, Amy, University of Central Florida
Abstract / Description: In today's society a beauty ideal exists in America, which attempts to define female beauty as fitting into a certain mold. Certain characteristics have been deemed the most attractive when it comes to female physical attractiveness, and an ideal image of beauty has been presented by the media. This research focuses on whether or not everyone buys into that beauty ideal, and examines the impact that a person's sex and race has on the physical characteristics which that individual defines as...
Show moreIn today's society a beauty ideal exists in America, which attempts to define female beauty as fitting into a certain mold. Certain characteristics have been deemed the most attractive when it comes to female physical attractiveness, and an ideal image of beauty has been presented by the media. This research focuses on whether or not everyone buys into that beauty ideal, and examines the impact that a person's sex and race has on the physical characteristics which that individual defines as the most appealing. Surveys were administered to 300 UCF students age 18-35. Participants were asked about ten different physical characteristics relating to women, and were asked to choose the characteristic among each group that they found the most physically attractive or beautiful. The study showed that both sex and racial differences do exist, and that there are variations in what different people consider beautiful. Not everyone has the same opinion on what is attractive in regards to the physical appearance of women.
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Date Issued: 2011
Identifier: CFH0004117, ucf:44862
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH0004117

Title: MODELED AND OBSERVED N2 LYMAN-BIRGE-HOPFIELD BAND EMISSIONS IN EARTH'S DAYGLOW: A COMPARISON.
Creator: Murray, Donald, Eastes, Richard, University of Central Florida
Abstract / Description: Ultraviolet (UV) spectra obtained from Earth's dayglow contain important information for understanding the thermosphere, and the N2 Lyman-Birge-Hopfield (LBH) bands are possibly the most useful emission. To be useful, a thorough understanding of how the LBH band emission varies with altitude and latitude is essential to present and future use of this emission by space-based remote sensors. Excited by photoelectron impact on N2 leading to transitions from the a 1Πg state to the ground...
Show moreUltraviolet (UV) spectra obtained from Earth's dayglow contain important information for understanding the thermosphere, and the N2 Lyman-Birge-Hopfield (LBH) bands are possibly the most useful emission. To be useful, a thorough understanding of how the LBH band emission varies with altitude and latitude is essential to present and future use of this emission by space-based remote sensors. Excited by photoelectron impact on N2 leading to transitions from the a 1Πg state to the ground state, the LBH emissions radiate between 1270 and 2400 Å. In addition to being populated by electron impact excitation, the a 1Πg state is populated by radiative and collisional cascading from adjacent singlet states a' 1Σu, and w 1Δu (Eastes, 2000). Ultimately, the intensity is most dependent on low energy electron flux (Ajello and Shemansky, 1985; Meier, 1991) because that is where the electron impact scattering cross sections of the singlet states are the largest. This dissertation presents modeled LBH profiles produced using the Intrasystem Cascade Excitation (ICE) model (Eastes, 2000) with photoelectron fluxes calculated using the Continuous Slowing Down (CSD) model (Jasperse, 1976). Both of these models implement the Mass Spectrometer and Incoherent Scatter (MSIS) to model an atmosphere. Modeled emissions are compared against observations by the High resolution Ionospheric and Thermospheric Spectrograph (HITS) on the Advanced Research and Global Observation Satellite (ARGOS). This dissertation will investigate the LBH emissions in detail and ultimately use them for remote sensing of thermospheric temperatures.
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Date Issued: 2007
Identifier: CFE0001986, ucf:47422
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001986

Title: On Hall Magnetohydrodynamics: X-type Neutral Point and Parker Problem.
Creator: Reger, Kyle, Shivamoggi, Bhimsen, Rollins, David, Eastes, Richard, University of Central Florida
Abstract / Description: The framework for the Hall magnetohydrodynamic (MHD) model for plasma physics is built up from kinetic theory and used to analytically solve problems of interest in the field. The Hall MHD model describes fast magnetic reconnection processes in space and laboratory plasmas. Specifically, the magnetic reconnection process at an X-type neutral point, where current sheets form and store enormous amounts of magnetic energy which is later released as magnetic storms when the sheets break up, is...
Show moreThe framework for the Hall magnetohydrodynamic (MHD) model for plasma physics is built up from kinetic theory and used to analytically solve problems of interest in the field. The Hall MHD model describes fast magnetic reconnection processes in space and laboratory plasmas. Specifically, the magnetic reconnection process at an X-type neutral point, where current sheets form and store enormous amounts of magnetic energy which is later released as magnetic storms when the sheets break up, is investigated. The phenomena of magnetic flux pile-up driving the merging of antiparallel magnetic fields at an ion stagnation-point flow in a thin current sheet, called the Parker problem, also receives rigorous mathematical analysis.
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Date Issued: 2012
Identifier: CFE0004428, ucf:49345
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004428

Title: SURVEY OF METEORITE PHYSICAL PROPERTIES: DENSITY, POROSITY AND MAGNETIC SUSCEPTIBILITY.
Creator: Macke, Robert, Britt, Daniel, University of Central Florida
Abstract / Description: The measurement of meteorite physical properties (i.e. density, porosity, magnetic susceptibility) supplements detailed chemical and isotopic analyses for small samples (thin sections or ~300 mg portions) by providing whole-rock data for samples massing in the tens of grams. With the advent of fast, non-destructive and non-contaminating measurement techniques including helium ideal-gas pycnometry for grain density, the Archimedean Ã‚Â"glass beadÃ‚Â" method...
Show moreThe measurement of meteorite physical properties (i.e. density, porosity, magnetic susceptibility) supplements detailed chemical and isotopic analyses for small samples (thin sections or ~300 mg portions) by providing whole-rock data for samples massing in the tens of grams. With the advent of fast, non-destructive and non-contaminating measurement techniques including helium ideal-gas pycnometry for grain density, the Archimedean Ã‚Â"glass beadÃ‚Â" method for bulk density and (with grain density) porosity, and the use of low-field magnetometry for magnetic susceptibility, all of which rely on compact and portable equipment, this has enabled a comprehensive survey of these physical properties for a wide variety of meteorites. This dissertation reports on the results of that survey, which spanned seven major museum and university meteorite collections as well as the Vatican collection. Bulk and grain densities, porosities and magnetic susceptibilities are reported for 1228 stones from 664 separate meteorites, including several rare meteorite types that are underrepresented in previous studies. Summarized here are data for chondrites (carbonaceous, ordinary and enstatite) and stony achondrites. Several new findings have resulted from this study. From the use of a Ã‚Â"weathering modulusÃ‚Â" based on grain density and magnetic susceptibility to quantify weathering in finds, it is observed that the degree of weathering of ordinary chondrites is dependent on their initial porosity, which becomes reduced to less than ~8% for all finds, but for enstatite chondrites weathering actually increases porosity. Grain density and magnetic susceptibility, which have been shown to distinguish H, L and LL ordinary chondrites, also may distinguish shergottites, nakhlites and chassignites from each other, but the two groups of enstatite chondrites (EH and EL) remain indistinguishable in these properties. H chondrite finds exhibit a slight negative trend in porosity with increasing petrographic type, and all chondrite falls together exhibit a pronounced negative trend in porosity spanning all petrographic types. The overall trend corresponds roughly to a positive trend in porosities with respect to both degree of oxidation and percentage of matrix. It also corresponds to the macroporosities of analogous asteroids. These traits constrain models of conditions in the solar nebula and the formation of chondrite parent-body precursors.
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Date Issued: 2010
Identifier: CFE0003424, ucf:48420
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0003424

Title: The Impact of Judo on Aggressive Behaviors in Youth with Autism Spectrum Disorder.
Creator: Rivera, Paola, Garcia, Jeanette, Fukuda, David, Stout, Jeffrey, University of Central Florida
Abstract / Description: The aim of this study was to examine the effects of an 8-week judo program on lifestyle habits and behavior in children with Autism Spectrum Disorder (ASD). METHODS: Participants included 25 children (ages 8-17), with a formal diagnosis of ASD. The sample participated in an 8-week judo program (45 minutes, 1x week), with measures taken at baseline and at the end of the 8-weeks. In order to assess activity levels and sleep quality, participants were instructed to wear Actigraph GT9X...
Show moreThe aim of this study was to examine the effects of an 8-week judo program on lifestyle habits and behavior in children with Autism Spectrum Disorder (ASD). METHODS: Participants included 25 children (ages 8-17), with a formal diagnosis of ASD. The sample participated in an 8-week judo program (45 minutes, 1x week), with measures taken at baseline and at the end of the 8-weeks. In order to assess activity levels and sleep quality, participants were instructed to wear Actigraph GT9X Accelerometers for 7 days and nights. In order to assess behavioral changes, parents were given the ABC survey to fill out at baseline and post-intervention. Non-parametric paired t-tests were conducted to compare differences in behaviors, MVPA, SB, and sleep quality (i.e. sleep efficiency, total sleep time, number of awakenings, and wake after sleep onset) pre and post judo. RESULTS: Results indicated there was a strong negative correlation (r= -0.632) with inappropriate behaviors and the number of classes attended. Participants also spent a significantly greater percentage of time in daily MVPA (8% vs 4%, p=0.05) following the program. There was a significant increase in total minutes of sleep duration (572.56 vs 333.8, p=0.008) following the program, and although not statistically significant, a trend existed for improved sleep efficiency (92% vs 88%, p=0.1). CONCLUSION: Despite no significant differences in ABC scores pre and post-judo, a strong association between class attendance and lower ABC scores were observed, along with improvements in MVPA and sleep quality. Future studies should include larger samples of youth with ASD, over a longer intervention period.
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Date Issued: 2019
Identifier: CFE0007525, ucf:52591
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007525

Title: Advanced Metrology and Diagnostic Loss Analytics for Crystalline Silicon Photovoltaics.
Creator: Schneller, Eric, Schoenfeld, Winston, Thomas, Jayan, Fenton, James, Coffey, Kevin, Sundaram, Kalpathy, University of Central Florida
Abstract / Description: Characterization plays a key role in developing a comprehensive understanding of the structure and performance of photovoltaic devices. High quality characterization methods enable researchers to assess material choices and processing steps, ultimately giving way to improved device performance and reduced manufacturing costs. In this work, several aspects of advanced metrology for crystalline silicon photovoltaic are investigated including in-line applications for manufacturing, off-line...
Show moreCharacterization plays a key role in developing a comprehensive understanding of the structure and performance of photovoltaic devices. High quality characterization methods enable researchers to assess material choices and processing steps, ultimately giving way to improved device performance and reduced manufacturing costs. In this work, several aspects of advanced metrology for crystalline silicon photovoltaic are investigated including in-line applications for manufacturing, off-line applications for research and development, and module/system level applications to evaluate long-term reliability. A frame work was developed to assess the cost and potential value of metrology within a manufacturing line. This framework has been published to an on-line calculator in an effort to provide the solar industry with an intuitive and transparent method of evaluating the economics of in-line metrology. One important use of metrology is in evaluating spatial non-uniformities, as localized defects in large area solar cells often reduce overall device performance. Techniques that probe spatial uniformity were explored and analysis algorithms were developed that provide insights regarding process non-uniformity and its impact on device performance. Finally, a comprehensive suite of module level characterization was developed to accurately evaluate performance and identify degradation mechanisms in field deployed photovoltaic modules. For each of these applications, case-studies were used to demonstrate the value of these techniques and to highlight potential use cases.
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Date Issued: 2016
Identifier: CFE0006499, ucf:51386
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006499

Title: Femtosecond Filament Interaction as a Probe for Molecular Alignment.
Creator: McKee, Erik, Richardson, Martin, Baudelet, Matthieu, Chang, Zenghu, University of Central Florida
Abstract / Description: Femtosecond laser filamentation is a highly nonlinear propagation mode. When a laser pulse propagates with a peak power exceeding a critical value Pcr (5 GW at 800 nm in air), the Kerr effect tends to collapse the beam until the intensity is high enough to ionize the medium, giving rise to plasma defocusing. A dynamic competition between these two effects takes place leaving a thin and weakly ionized plasma channel in the trail of the pulse. When an ultrafast laser pulse interacts with...
Show moreFemtosecond laser filamentation is a highly nonlinear propagation mode. When a laser pulse propagates with a peak power exceeding a critical value Pcr (5 GW at 800 nm in air), the Kerr effect tends to collapse the beam until the intensity is high enough to ionize the medium, giving rise to plasma defocusing. A dynamic competition between these two effects takes place leaving a thin and weakly ionized plasma channel in the trail of the pulse. When an ultrafast laser pulse interacts with molecules, it will align them, spinning them about their axis of polarization. As the quantum rotational wave packet relaxes, the molecules will experience periodic field-free alignment. Recent work has demonstrated the effect of molecular alignment on laser filamentation of ultra-short pulses. Revival of the molecular alignment can modify filamentation parameters as it can locally modify the refractive index and the ionization rate. In this thesis, we demonstrate with simulations and experiments that these changes in the filament parameters (collapse distance and filament plasma length) can be used to probe molecular alignment in CO2.
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Date Issued: 2013
Identifier: CFE0005033, ucf:50000
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005033

Title: AR Physics: Transforming physics diagrammatic representations on paper into interactive simulations.
Creator: Zhou, Yao, Underberg-Goode, Natalie, Lindgren, Robb, Moshell, Jack, Peters, Philip, University of Central Florida
Abstract / Description: A problem representation is a cognitive structure created by the solver in correspondence to the problem. Sketching representative diagrams in the domain of physics encourages a problem solving strategy that starts from 'envisionment' by which one internally simulates the physical events and predicts outcomes. Research studies also show that sketching representative diagrams improves learner's performance in solving physics problems. The pedagogic benefits of sketching representations on...
Show moreA problem representation is a cognitive structure created by the solver in correspondence to the problem. Sketching representative diagrams in the domain of physics encourages a problem solving strategy that starts from 'envisionment' by which one internally simulates the physical events and predicts outcomes. Research studies also show that sketching representative diagrams improves learner's performance in solving physics problems. The pedagogic benefits of sketching representations on paper make this traditional learning strategy remain pivotal and worthwhile to be preserved and integrated into the current digital learning landscape.In this paper, I describe AR Physics, an Augmented Reality based application that intends to facilitate one's learning of physics concepts about objects' linear motion. It affords the verified physics learning strategy of sketching representative diagrams on paper, and explores the capability of Augmented Reality in enhancing visual conceptions. The application converts the diagrams drawn on paper into virtual representations displayed on a tablet screen. As such learners can create physics simulation based on the diagrams and test their (")envisionment(") for the diagrams. Users' interaction with AR Physics consists of three steps: 1) sketching a diagram on paper; 2) capturing the sketch with a tablet camera to generate a virtual duplication of the diagram on the tablet screen, and 3) placing a physics object and configuring relevant parameters through the application interface to construct a physics simulation.A user study about the efficiency and usability of AR Physics was performed with 12 college students. The students interacted with the application, and completed three tasks relevant to the learning material. They were given eight questions afterwards to examine their post-learning outcome. The same questions were also given prior to the use of the application in order to comparewith the post results. System Usability Scale (SUS) was adopted to assess the application's usability and interviews were conducted to collect subjects' opinions about Augmented Reality in general. The results of the study demonstrate that the application can effectively facilitate subjects' understanding the target physics concepts. The overall satisfaction with the application's usability was disclosed by the SUS score. Finally subjects expressed that they gained a clearer idea about Augmented Reality through the use of the application.
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Date Issued: 2014
Identifier: CFE0005566, ucf:50292
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005566

Title: Getting The Work Out of Workouts: Evaluating the Effectiveness and Outcomes of a Physical Exercise Motivational Intervention For Older Workers.
Creator: Sholar-Fetherlin, Brandon, Fritzsche, Barbara, Smither, Janan, Wang, Wei, Fragala, Maren, University of Central Florida
Abstract / Description: To mitigate their estimated $300 billion in annual health-related losses, many companies have instituted workplace wellness initiatives designed to promote physical activity among their employees, improving the overall health of their workforce. Though middle-aged and older workers may potentially enjoy the greatest physical, stress and cognitive benefits from regular exercise, workplace wellness programs have been less successful in attracting such employees. This study developed and tested...
Show moreTo mitigate their estimated $300 billion in annual health-related losses, many companies have instituted workplace wellness initiatives designed to promote physical activity among their employees, improving the overall health of their workforce. Though middle-aged and older workers may potentially enjoy the greatest physical, stress and cognitive benefits from regular exercise, workplace wellness programs have been less successful in attracting such employees. This study developed and tested a 6-week exercise motivation intervention designed to meet the needs of sedentary, older working adults and to determine what non-physical benefits might result from increased levels of physical exercise. The intervention, based primarily on Self-Determination Theory, included feedback on individually-made, realistic, process-specific exercise goals that and provided guidance from knowledgeable exercise professionals in addition to support group of socially-similar individuals to aid in coping and adherence. The intervention was built and delivered entirely online to fit better with the sample's considerable time demands. The motivational intervention was delivered to a sample of 30 mostly-older working adults and was successful in significantly improving activity levels and overall affect while decreasing stress. No significant differences were detected in measures of personal resources, work engagement, work effort and task performance. The implications and recommendations for future research are discussed.
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Date Issued: 2017
Identifier: CFE0006660, ucf:51235
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006660

Title: SHORT TERM EXAMINATION OF PHYSICAL ACTIVITY AND SLEEP QUALITY WITH CHILDREN WITH AUTISM SPECTRUM DISORDER.
Creator: Barnes, Demani Barak, Garcia, Jeanette M., Fukuda, David H., University of Central Florida
Abstract / Description: Children diagnosed with Autism Spectrum Disorder (ASD) may not be meeting the recommended amounts of physical activity (PA) or obtain a sufficient amount of sleep, however, few studies have objectively compared PA, sedentary behavior, and sleep quality between typically developing (TD) youth, and youth with ASD. Therefore, the purpose of this study was to compare levels of PA, sedentary behavior, and sleep quality between youth with ASD and TD youth. Twenty-three children with ASD and 12 TD...
Show moreChildren diagnosed with Autism Spectrum Disorder (ASD) may not be meeting the recommended amounts of physical activity (PA) or obtain a sufficient amount of sleep, however, few studies have objectively compared PA, sedentary behavior, and sleep quality between typically developing (TD) youth, and youth with ASD. Therefore, the purpose of this study was to compare levels of PA, sedentary behavior, and sleep quality between youth with ASD and TD youth. Twenty-three children with ASD and 12 TD children wore the Actigraph GT9X accelerometer over seven days and nights to assess activity and sleep. Youth with ASD had significantly greater levels of sedentary behavior (p=.02), and had less sleep efficiency compared to TD youth (p=.0001). Additionally, TD youth were more likely to achieve the recommended levels of PA compared to youth with ASD (p=.003). Results suggest that youth with ASD have poorer health habits compared to TD youth. Interventions should be developed to target health behaviors in youth with ASD.
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Date Issued: 2019
Identifier: CFH2000490, ucf:45830
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH2000490

Title: HEALTH ATTITUDES, KNOWLEDGE AND LITERACY OF PRIMARY CAREGIVERS WITH ELEMENTARY SCHOOL CHILDREN.
Creator: Stuib, Susan, Sivo, Stephen, University of Central Florida
Abstract / Description: Previous research has indicated that physical activity and healthy eating in elementary school children are the exception rather than the norm. Increased attention to the rising rates of childhood obesity, coupled with the recognition that changes in the school environment are critical to reducing this trend, has intensified the need to adopt better practices in school nutrition, physical activity and physical education. Apart from being physically active, children need to learn fundamental...
Show morePrevious research has indicated that physical activity and healthy eating in elementary school children are the exception rather than the norm. Increased attention to the rising rates of childhood obesity, coupled with the recognition that changes in the school environment are critical to reducing this trend, has intensified the need to adopt better practices in school nutrition, physical activity and physical education. Apart from being physically active, children need to learn fundamental motor skills and develop health related physical fitness (cardiovascular endurance, muscular strength and endurance, flexibility, and body composition). Primary caregivers play an important part in developing and teaching children these things through example and through conversations with their children. The purpose of this study was to examine the level of knowledge primary caregivers have about health and nutritional practices and whether primary caregivers' health practices, health knowledge or health literacy about nutrition and health affects their children's well-being and health practices. Based on the results from the questionnaire in this study targeted at primary caregivers of elementary school-age children, primary caregivers' health literacy, knowledge and attitudes of health were directly linked with their children's health and well-being and children's health practices.
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Date Issued: 2006
Identifier: CFE0001383, ucf:46990
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001383

Title: MODELING, SIMULATION, AND VISUALIZATION OF 3D LUNG DYNAMICS.
Creator: Santhanam, Anand, Rolland, Jannick, University of Central Florida
Abstract / Description: Medical simulation has facilitated the understanding of complex biological phenomenon through its inherent explanatory power. It is a critical component for planning clinical interventions and analyzing its effect on a human subject. The success of medical simulation is evidenced by the fact that over one third of all medical schools in the United States augment their teaching curricula using patient simulators. Medical simulators present combat medics and emergency providers with video-based...
Show moreMedical simulation has facilitated the understanding of complex biological phenomenon through its inherent explanatory power. It is a critical component for planning clinical interventions and analyzing its effect on a human subject. The success of medical simulation is evidenced by the fact that over one third of all medical schools in the United States augment their teaching curricula using patient simulators. Medical simulators present combat medics and emergency providers with video-based descriptions of patient symptoms along with step-by-step instructions on clinical procedures that alleviate the patient's condition. Recent advances in clinical imaging technology have led to an effective medical visualization by coupling medical simulations with patient-specific anatomical models and their physically and physiologically realistic organ deformation. 3D physically-based deformable lung models obtained from a human subject are tools for representing regional lung structure and function analysis. Static imaging techniques such as Magnetic Resonance Imaging (MRI), Chest x-rays, and Computed Tomography (CT) are conventionally used to estimate the extent of pulmonary disease and to establish available courses for clinical intervention. The predictive accuracy and evaluative strength of the static imaging techniques may be augmented by improved computer technologies and graphical rendering techniques that can transform these static images into dynamic representations of subject specific organ deformations. By creating physically based 3D simulation and visualization, 3D deformable models obtained from subject-specific lung images will better represent lung structure and function. Variations in overall lung deformations may indicate tissue pathologies, thus 3D visualization of functioning lungs may also provide a visual tool to current diagnostic methods. The feasibility of medical visualization using static 3D lungs as an effective tool for endotracheal intubation was previously shown using Augmented Reality (AR) based techniques in one of the several research efforts at the Optical Diagnostics and Applications Laboratory (ODALAB). This research effort also shed light on the potential usage of coupling such medical visualization with dynamic 3D lungs. The purpose of this dissertation is to develop 3D deformable lung models, which are developed from subject-specific high resolution CT data and can be visualized using the AR based environment. A review of the literature illustrates that the techniques for modeling real-time 3D lung dynamics can be roughly grouped into two categories: Geometrically-based and Physically-based. Additional classifications would include considering a 3D lung model as either a volumetric or surface model, modeling the lungs as either a single-compartment or a multi-compartment, modeling either the air-blood interaction or the air-blood-tissue interaction, and considering either a normal or pathophysical behavior of lungs. Validating the simulated lung dynamics is a complex problem and has been previously approached by tracking a set of landmarks on the CT images. An area that needs to be explored is the relationship between the choice of the deformation method for the 3D lung dynamics and its visualization framework. Constraints on the choice of the deformation method and the 3D model resolution arise from the visualization framework. Such constraints of our interest are the real-time requirement and the level of interaction required with the 3D lung models. The work presented here discusses a framework that facilitates a physics-based and physiology-based deformation of a single-compartment surface lung model that maintains the frame-rate requirements of the visualization system. The framework presented here is part of several research efforts at ODALab for developing an AR based medical visualization framework. The framework consists of 3 components, (i) modeling the Pressure-Volume (PV) relation, (ii) modeling the lung deformation using a Green's function based deformation operator, and (iii) optimizing the deformation using state-of-art Graphics Processing Units (GPU). The validation of the results obtained in the first two modeling steps is also discussed for normal human subjects. Disease states such as Pneumothorax and lung tumors are modeled using the proposed deformation method. Additionally, a method to synchronize the instantiations of the deformation across a network is also discussed.
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Date Issued: 2006
Identifier: CFE0001301, ucf:47033
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001301

Title: SOCIAL COMPETENCE OF HIGH SCHOOL STUDENTS ENROLLED IN ONLINE PHYSICAL EDUCATION COURSES.
Creator: Ware, Deborah, Higginbotham, Patricia, University of Central Florida
Abstract / Description: The purpose of this study was to assess the social competence of high school students enrolled in online Physical Education courses. Additionally, the demographic information regarding students who enroll in online Physical Education courses was examined. The subjects for this study included sixty students taking one of two Physical Education courses at the Florida Virtual School during the spring 2005 term. The entire curriculum of the Florida Virtual School is presented online and students...
Show moreThe purpose of this study was to assess the social competence of high school students enrolled in online Physical Education courses. Additionally, the demographic information regarding students who enroll in online Physical Education courses was examined. The subjects for this study included sixty students taking one of two Physical Education courses at the Florida Virtual School during the spring 2005 term. The entire curriculum of the Florida Virtual School is presented online and students live throughout the entire state of Florida. Therefore, the entire study was administered online. The assessment instrument used was the Teenage Inventory of Social Skills created by Heidi Inderbitzen. The Teenage Inventory of Social Skills is a 40-item self-report questionnaire consisting of statements rated on a 6-point continuum. The instrument was divided into two sub-scales; a positive scale and a negative scale. A One-Sample T-Test was used to compare the mean sample scores with the standard means. Frequencies were run to review demographic information. Results indicated that there was no significant mean difference found between the students enrolled in online Physical Education courses and the mean of students established by the TISS. The majority of respondents were female, Caucasian, and were attending public or private schools for most of their classes.
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Date Issued: 2005
Identifier: CFE0000624, ucf:46532
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000624

physical activity (9)	+ -
Physical Activity (5)	+ -
physics (5)	+ -
children (4)	+ -
diet (3)	+ -

physical appearance (3)	+ -
Augmented Reality (2)	+ -
Chalmers (2)	+ -
Exercise (2)	+ -
Nutrition (2)	+ -
Studio Physics (2)	+ -
child abuse (2)	+ -
consciousness (2)	+ -
high school (2)	+ -
laser physics (2)	+ -
optics (2)	+ -
pediatric (2)	+ -
physical (2)	+ -
physical abuse (2)	+ -
physical attractiveness (2)	+ -
physical disabilities (2)	+ -
physical education (2)	+ -
physical optics (2)	+ -
physicalism (2)	+ -
plasma physics (2)	+ -
single molecule magnets (2)	+ -
social presence (2)	+ -
spectroscopy (2)	+ -
technology (2)	+ -
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ETD Collection (67)	+ -
Honors Collection (19)	+ -

University of Central Florida (86)	+ -
Valdes, Anna (5)	+ -
Del Barco, Enrique (4)	+ -
Garcia, Jeanette (4)	+ -
Mucciolo, Eduardo (4)	+ -

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