Physical Sciences and Mathematics Commons^™

Hierarchical Conjugated Polymer Systems Prepared By Controlled Chain-Growth Polymerization, Chunwa Peter Kei

LSU Doctoral Dissertations

π-Conjugated polymer materials may have a significant economic impact on society by providing means for designing affordable, flexible, and portable organic electronic devices. Their successful commercialization will depend on major scientific advancements, which will challenge human society to seek out ever more detailed and fundamental processes to command. Controlled polymerization affords such a power; allowing for the design of meticulous and precisely defined systems granting detailed insight into structure-property relationships in the polymer materials and bettering understanding of novel physical phenomena.

This dissertation primarily focuses on development and preparation of well-defined hierarchically organized macromolecular systems. The novel chain-growth polymerization methodologies …

Visible Light And Electron Transfer Chemistry For O-Glycosylation And Remote Hydroxylation, Mark Louis Spell

LSU Doctoral Dissertations

This dissertation focuses on the synthesis of dauer pheromone analogs for biological evaluation, the development of visible light promoted O-glycosylation methods and the development of an Ir(ppy)3 catalyzed C-H hydroxylation method. Chapter 1 describes the synthesis of dauer pheromone analogs. C.elegans is a small nematode that enters a dauer stage when encountering unfavorable environmental conditions. The dauer stage is initiated by the nematodes chemosensation of the dauer pheromone caused by the down regulation biochemical pathways TGF-â and IGF-1. These biochemical pathways are also seen in Homo Sapiens and play a role in a number of biological processes. Understanding how these …

The Implementation Of Two Cooperative Learning Structures, Rally Coach And Teams-Games-Tournaments, In High School Chemistry Courses, Joanna Miketinas Stewart

LSU Master's Theses

To combat the obstacles that students experience in chemistry, two cooperative learning strategies, Rally Coach and Teams-Games-Tournaments, were implemented in five chemistry courses at East Ascension High School. Rally Coach called for two students to work as a pair and peer tutor to successfully complete practice problems for each lesson. Teams-Games-Tournaments required students to work in groups of four to complete practice problems and compete for team points as a review. Every student experienced both learning strategies. A comparison was made to see which cooperative learning strategy better helped student performance, including comparisons of effects on different student demographics and …

The Effect Of Manipulatives On Students' Understanding Of Chemistry Concepts, Jasmine W. Banks

LSU Master's Theses

The purpose of this study was to assess the effectiveness of manipulatives on chemistry concepts. Manipulative activities were designed for four chemistry topics: Dimensional Analysis, Ionic Formulas, Molecular Shapes, and Stoichiometry. Seventy-five high school students were divided into a control or experimental group. The control group solved problems in small groups, while the experimental group used manipulatives to complete a guided activity. Students in the control group scored significantly higher on the posttest for the Dimensional Analysis and Ionic Formulas activities. There was no significant difference in the posttest scores for the Molecular Shapes and Stoichiometry posttest. While manipulatives can …

The Use Of Classroom Demonstrations To Improve High School Students' Ability To Understand Concepts In Chemistry, Jessica Langlois Shelton

LSU Master's Theses

This study was completed to determine if implementing demonstrations in specific chapters of a high school chemistry classroom would enhance students understanding of the topics the demonstrations represented. The study consisted of five sections of college preparatory high school chemistry. The sections were made up of both male and female students. The sections were randomly broken up into two groups. Each group acted as the experimental and control at different points in the study. Four chapters were used in the study. Each group represented the control group in two chapters and the experimental group in two chapters, flip flopping with …

The Effects Of Implementing The Cooperative Learning Structure, Numbered Heads Together, In Chemistry Classes At A Rural, Low Performing High School, Daniel Paul Baker

LSU Master's Theses

Due to the positive academic results in numerous studies on cooperative learning and the need and desire to improve academic results in East Feliciana High School Chemistry classes, the implementation of a cooperative learning structure called “numbered heads together” was studied during the spring 2013 semester at this rural, low performing high school. Numbered heads together was utilized during three units of a Chemistry class with 24 students and three units of an AP Chemistry with 11 students after completion of two units taught without the use of any type of cooperative learning structure. Using pre- and post-tests, learning gain …

Surface Studies Of Organic Thin Films Using Scanning Probe Microscopy And Nanofabrication, Venetia Denae Lyles

LSU Doctoral Dissertations

Porphyrins and metalloporphyrins have unique chemical and electronic properties and thus provide useful model structures for nanoscale studies of the role of chemical structure for electronic properties. Porphyrins have been proposed as viable materials for molecular-based information-storage devices, gas sensors, photovoltaic cells, organic light-emitting diodes and molecular wires. The function and efficiency of porphyrins in devices is largely attributable to molecular architecture and how the molecules are self-organized. Modifications of the porphyrin macrocycle, peripheral groups or bound metal ions can generate a range of electrical, photoelectrical or magnetic properties. The conductive properties are greatly influenced at the molecular level by …

Wet And Dry Aging Of Polymer-Asphalt Blends: Chemistry And Performance, Ionela Chiparus Glover

LSU Doctoral Dissertations

A PG 76-22 Polymer Modified Asphalt Cement composition was subjected in the laboratory to accelerated aging using both a standard Thin Film Oven Test and a Pressure Aging Vessel. Conditions simulating wet atmospheres (PAV in saturated water vapors) as well as very long service terms (multiple dry and wet PAV operations) were studied. A Rotating Cylinder Aging Test has been employed as an alternate asphalt aging technique using the same PMAC composition in order to observe the initial phases of the oxidative aging process. The data provided by this technique was correlated with the actual aging in the field of …

Modeling Longleaf Pine (Pinus Palustris Mill) Wood Properties Using Near Infrared Spectroscopy, Brian Kipling Via

LSU Doctoral Dissertations

This research demonstrated model development for important wood properties using near infrared spectroscopy (NIR); it considered the effect of outside sources of error, and the ability of NIR to measure fiber morphology. Strength, stiffness, and density were successfully modeled from wood samples taken throughout 10 longleaf (Pinus palustris Mill) trees. Principal components and multiple linear regression were compared for performance in prediction of density, strength, and stiffness. I found both modeling techniques to yield similar prediction accuracies. However, I found that density could be estimated through Beer-Lambert’s law since the absorbance at all wavelengths increased with density. Also, 5 of …