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Intrinsic Gas-Phase Behavior Of Uranium Species: A Comprehensive Reactivity Study Of [O=U≡Ch]+ And [Uh]+, Justin Terhorst

Electronic Theses and Dissertations

The intrinsic chemistry of actinide elements, particularly uranium, remains a key challenge in understanding f-block reactivity due to the complexity introduced by solvent interactions, counter-ions, and complex equilibria in the condensed phase. In this dissertation, a systematic gas-phase study utilizing preparative tandem ion-trap mass spectrometry (PTMSⁿ) is presented, focusing on the reactivity of uranium-centered species, specifically [OUCH]⁺, an oxy uranium methylidyne species, and [UH]⁺ ions. By stripping away solvent effects and isolating the ions, PTMSⁿ provides a powerful platform to probe the fundamental chemical behavior of uranium species in their intrinsic state.

The …

Combined In Silico And Experimental Approaches Of Pharmacognosy To Resolve Complex Natural Product Issues, William Michael Neal

Electronic Theses and Dissertations

Since the identification of useful bioactive natural products can often involve tedious dereplication measures to decipher complex mixtures, much emphasis is placed on methods that can effectively characterize natural products. Several in silico methods, such as quantitative structure-activity relationships (QSARs), molecular docking, and quantum calculations, provide researchers with valuable tools to overcome the challenge of complex natural product mixtures. To exemplify the abilities of computational methodologies to further the field of pharmacognosy, this dissertation elaborates on several research projects involving computational approaches in pharmacognosy, including: (1) global assessment of pregnane X receptor (PXR) agonism via multiple QSAR models, (2) differentiation …

Computational Quantum Chemistry Studies Of The Stabilities Of Radical Adducts Formed During The Oxidation Of Melatonin Derivatives, James Horne

Electronic Theses and Dissertations

Melatonin is a natural antioxidant that has been investigated for properties as a potential spin trap to identify short-lived free radicals. Computational quantum chemistry studies have been performed for the oxidation of melatonin to N¹-acetyl-N²-formyl-5-methoxykynuramine. This research focused on modification of melatonin into derivatives and analyzing the change in total molecular energy from melatonin to its oxidation product, as well as the corresponding derivatives. Each of the molecular geometries were optimized at the DFT/B3LYP/6-31G(d), DFT/B3LYP/cc-pVXZ (X = D, T), HF/6-31G(d), HF/cc-PVXZ (X = D, T), MP2/6-31G(d), and MP2/cc-PVXZ (X = D, T) levels of theory. …

Development And Assessment Of Gamified Process-Oriented Guided Inquiry Learning Activities In Undergraduate Large Lecture Chemistry Courses, Nathan Turner

Electronic Theses and Dissertations

Students who take general chemistry and do not perform well are more likely to pursue an alternative degree or remove themselves from STEM curriculum entirely. Poor academic performance and high student attrition rates in general chemistry courses have resulted in the perception of chemistry courses being gatekeepers for students in pursuit of STEM degrees. Process-Oriented Guided Inquiry Learning (POGIL) has shown promising results in both lecture and laboratory teaching on student performance in chemistry while gamification has been used to enhance student learning experiences to help students grasp chemistry concepts. The current project blends two student-centered approaches, gamification and POGIL, …

Pedagogical Content Knowledge (Pck) Change And Professional Development For Educators: An Assessment Of A Master’S In Chemistry Program For High School Science Teachers, Mary Charlotte Bautista

Electronic Theses and Dissertations

The M.S. Chemistry – Chemical Education Specialization program at South Dakota State University provides in-depth general chemistry coursework to in-service high school science teachers in a virtual format. The goal of the program is for the teachers enrolled to become more effective teachers while gaining content knowledge in chemistry; in essence, to increase their pedagogical content knowledge (PCK). The aim of this study is to follow participants through their experience in this program in order to understand how the program’s requirements enhance its participants’ teaching and learning. A narrative framework follows one participant through their two-year experience in the program, …

Students’ Perceptions Of Specific Laboratory Curricula On The Learning Experience In Chemistry Courses, Arwa Ali Alshehri

Electronic Theses and Dissertations

Laboratory courses play a key role in developing critical thinking and problem-solving skills and providing experience in certain aspects of a laboratory setting including reactions, materials, and equipment. Prior studies suggest that a laboratory course assists students toward cognitive gain on lecture content. In contrast, other studies conclude that laboratory is uncorrelated with cognitive gain on lecture content. Thus, a discord exists between researchers regarding the role that laboratory experiences play in furthering the understanding of chemistry concepts taught in lectures. The purpose of this research is to examine the impact of two different laboratory curricula on students’ performance in …

Diversity And Inclusion In Science Teaching Learning (Distl): Focusing On The Perspectives Of Undergraduate Students And Graduate Teaching Assistants In The Chemistry Classroom, Albert Aidoo

Electronic Theses and Dissertations

Students in Science, Technology, Engineering and Mathematics (STEM) come with a wide range of experiences and educational backgrounds. There is high attrition rate and low academic achievement among students in STEM areas, specifically in college chemistry courses that are prerequisites for many STEM majors. Hence it is important to look at diversity and inclusion specifically in first- and second-year college chemistry courses to address the challenge of student attrition in STEM. Diversity can be understood as the differences each student brings along the dimensions of prior knowledge, skills, race, ethnicity, sexual orientation, gender, socio-economic status, age, ability, religious or political …

College Students Conceptions Of Particulate Nature Of Matter And The Impact On Research Instrumentation, Bridget Klutse

Electronic Theses and Dissertations

The main objective of this research was to explore the understanding and conceptions of Particulate Nature of Matter (PNM) with Chem 115 L students as the participants. Conceptions were defined specifically as beliefs and alternative beliefs about topics. The research also assessed the impact of analytical instrumentation in the chemistry laboratory on learning chemistry concepts. Eight questions (8) with multiple choice answers were administered to 10 students at the beginning and after the Fall 2018 semester via selective/purposeful sampling. Data were collected using surveys (pre- and post-surveys) and interviews (pre- and postinterviews), then analyzed quantitatively and qualitatively. The eight questions …

Technology-Based Culturally Relevant Chemistry Education (Crce), Mercy Adoma Fosu

Electronic Theses and Dissertations

The relevance of chemistry concepts and principles remains a challenge for most students enrolled in college chemistry courses. Part of this problem is the disconnect with what students experience in their every-day lives, and how the material, specifically chemistry content is presented via textbooks, lectures, and laboratory teaching. Moreover, the teaching of general chemistry has traditionally focused on traditional, instructor-centric expository delivery of course materials, that treats students as empty vessels devoid of prior knowledge. Students prior knowledge and experiences are crucial in shaping their understanding of scientific concepts and principles. Even students with relatively low expectations for success in …

Implementing And Assessing The Use Of A New Strategy For Training Chemistry Graduate Teaching Assistants, Amanda Hyett

Electronic Theses and Dissertations

Graduate teaching assistants (GTAs) largely contribute to undergraduate education but are often underprepared for their role as educators. Most graduate students attend graduate school to perform research and are then asked to teach for the first time without sufficient pedagogy training. To assist in increasing the GTAs pedagogical knowledge, a scenario-based activity series was developed and implemented for first- and second-year GTAs. Developing scenario-based scenarios from actual laboratory events provided GTAs with the opportunity to practice prior to engaging in the laboratory classroom. The Teaching Assistant Intervention Activities (TAIAs) included topics such as interpersonal skills and behaviors, group process, working …

Computational Quantum Chemistry Studies Of The Interactions Of Amino Acids Side Chains With The Guanine Radical Cation., Edward Acheampong

Electronic Theses and Dissertations

Guanine is generally accepted as the most easily oxidized DNA base when cells are subjected to ionizing radiation, photoionization or photosensitization. At pH 7, the midpoint reduction potential is on the order of 0.2 – 0.3 V higher than those of the radicals of e.g. tyrosine, tryptophan cysteine and histidine, so that the radical “repair” (or at least, a thermodynamically favorable reaction) involving these amino acids is feasible. Computational quantum studies have been done on tyrosine, tryptophan, cysteine and histidine side chains as they appear in histones. Density functional theory was employed using B3LYP/6-31G+ (d, p) basis set to study …

The Relationship Between Recollection, Knowledge Transfer, And Student Attitudes Towards Chemistry, Oluwatobi Omobonike Odeleye

Electronic Theses and Dissertations

Certain foundational concepts, including acid-base theory, chemical bonding and intermolecular forces (IMFs), appear throughout the undergraduate chemistry curriculum. The level of understanding of these foundational concepts influences the ability of students to recognize the relationships between sub-disciplines in chemistry. The purpose of this study was to investigate the relationship between student attitudes towards chemistry and their abilities to recollect and transfer knowledge of IMFs, a foundational concept, to their daily lives as well as to other classes. Data were collected using surveys, interviews and classroom observations, and analyzed using qualitative methods. The data show that while most students were able …

Computational Quantum Chemistry Studies Of The Stabilities Of Radical Intermediates Formed During The Oxidation Of Melatonin, Constance E. Warden

Electronic Theses and Dissertations

Melatonin, a nontoxic natural antioxidant, is of interest as a possible spin trap for use in spectroscopic methods to observe and identify short-lived free radicals, which have been linked to oxidative stress that may result in serious health problems. However, the reaction mechanisms for the oxidation of melatonin to form the product N¹-acetyl-N²-formyl-5-methoxykynuramine are still not well understood. Computational quantum chemistry studies have been done on four proposed reaction mechanisms, involving the following major intermediate structures: a dioxetane, an epoxide, a melatonin radical cation, and a spin radical adduct. Molecular geometries were optimized at the …

Computational Studies Of Spin Trapping Of Biologically Relevant Radicals By New Heteroaryl Nitrones, Eyram Asempa

Electronic Theses and Dissertations

Heteroaryl nitrone spin traps have been suggested to act as free radical scavengers. The geometry optimizations and the single-point energies of the spin trapping reactions of the heteroaryl nitrones, 5,5-dimethylpyrroline-N-oxide (DMPO) and α-phenyl-N-t-butylnitrone (PBN) have been computationally studied using ab initio (Hartree-Fock (HF) and second-order Møller-Plesset (MP2)) methods and Density Functional Theory (DFT) methods. The effects of new heteroaryl substituents on a parent nitrone spin trap have been examined at the HF and MP2 levels with the 6-31G*, and cc-pVnZ (n=D, T, Q) basis sets. The thermodynamics of the spin trapping at the C-site and O-site with •H, …

Strengthening Stem Performance And Persistence : Influence Of Undergraduate Teaching Assistants On Entry-Level Stem Students., Stephanie B. Philipp

Electronic Theses and Dissertations

Increasing retention of students in science, technology, engineering, or mathematics (STEM) programs of study is a priority for many colleges and universities. This study examines an undergraduate teaching assistant (UTA) program implemented in a general chemistry course for STEM majors to provide peer learning assistance to entry-level students. This study measured the content knowledge growth of UTAs compared to traditional graduate teaching assistants (GTAs) over the semester, and described the development of peer learning assistance skills of the UTAs as an outcome of semester-long training and support from both science education and STEM faculty. Impact of the UTA program on …

Little Sewickley Creek: The Redesignation Process Of A High Quality Stream To An Exceptional Value Stream, Nathan Todd Reinhart

Electronic Theses and Dissertations

The Pennsylvania Department of Environmental Protection has set designated uses for all of the 83,000 miles of waterways based on their quality. Only the highest quality streams are afforded the highest protection with a High Quality (HQ) or Exceptional Value (EV). Little Sewickley Creek is designated as a High Quality-Trout Stocking Fishery and may warrant redesignation as an Exceptional Value waterway. The aim of the study was to provide technical data on the stream to support an EV reclassification. The report has compiled previous data and collected new data in order to file a formal petition to the PA DEP. …

Age As A Factor In Inter-Tissue Spacing Of Stable Carbon Isotope Values In Juvenile Human Remains From The Dakhleh Oasis, Egypt, Annie Laurie Norris

Electronic Theses and Dissertations

Although stable isotope analysis is routinely utilized in bioarchaeology and relies on principles that are well-understood, there are still fundamental issues that have not been thoroughly investigated. This thesis examines the relationship between inter-tissue spacing of carbon stable isotope values (δ13C) and age in juvenile human remains. Analyses of tissues within the same individual reveal disparate isotopic values for a variety of physiological and biological reasons discussed herein. This project examines the distance between the δ13C values in bone collagen, skin, hair, and nail, and examines how these distances vary between different age groups, utilizing data collected from 52 well-preserved …

New Synthetic Methodologies For The Construction And Optimization Of Natural Products, Amir E. Wahba

Electronic Theses and Dissertations

Toxicity associated with bioactive natural products is considered as a major obstacle in the process of drug discovery. Manzamine A (MA) is one such candidate that requires optimization to overcome the toxicity problem. The manzamine alkaloids represents a unique class of natural products that have shown a diverse range of bioactivities including antimicrobial, antiparasitic, cytotoxicity, anti-inflammatory, pesticidial, and was shown to possess activity against HIV-1 and AIDS opportunistic infections. The greatest potential for the manzamine alkaloids appears to be against malaria and neuroinflammation. Experimental and modeling studies suggested that the planer ?-carboline moiety can act as DNA intercalator and hence …

Toward The Synthesis Of Nuclease Models., Enni Nina Fomumbod

Electronic Theses and Dissertations

Nucleases are enzymes that can specifically recognize nucleic acids and hydrolyze their phosphodiester bonds effectively. As is the case with many hydrolases, nucleases often carry one or more metal centers. Cooperation between such metal centers and other interactions involving general acid-base activities are believed to be essential in multifunctional catalyses. Combination of such interactions in model compounds often resulted in larger than additive effects.

This work is aimed at synthesizing nuclease models that combine the ability to recognize phosphate groups and/or nitrogen bases of DNA together with the ability to catalyze phosphodiester hydrolysis. These models were designed to achieve optimum …

A Computational Chemistry Study Of Spin Traps., Jacob Fosso-Tande

Electronic Theses and Dissertations

Many defects in physiological processes are due to free radical damage: reactive oxygen species, nitric oxide, and hydroxyl radicals have been implicated in the parthenogenesis of cancer, diabetes mellitus, and rheumatoid arthritis. We herein characterize the phenyl-N-ter-butyl nitrone (PBN) type spin traps in conjunction with the most studied dimethyl-1-pyrroline-N-oxide (DMPO) type spin traps using the hydroxyl radical. In this study, theoretical calculations are carried out on the two main types of spin traps (DMPO and PBN) at the density functional theory level (DFT). The energies of the optimized structures, hyperfine calculations in gaseous and aqueous phases of the spin traps …

Slurry Chemistry Effects On Copper Chemical Mechanical Planarization, Ying Luo

Electronic Theses and Dissertations

Chemical-mechanical Planarization (CMP) has emerged as one of the fastest-growing processes in the semiconductor manufacturing industry, and it is expected to show equally explosive growth in the future (Braun, 2001). The development of CMP has been fueled by the introduction of copper interconnects in microelectronic devices. Other novel applications of CMP include the fabrications of microelectromechanical systems (MEMS), advanced displays, three dimensional systems, and so on (Evans, 2002). CMP is expected to play a key role in the next-generation micro- and nanofabrication technologies (Singh, et al., 2002). Despite the rapid increase in CMP applications, the fundamental understanding of the CMP …

An Analysis And Evaluation Of Chemical Education Selected South Dakota Secondary Schools, Bernal A. Kiser

Electronic Theses and Dissertations

In the past fifty years, numerous achievements have been made in the science of chemistry. Such achievements have required changes, both in industrial chemistry and in the teaching of chemistry. Traditionally, beginning chemistry has been taught as a descriptive science. Even presently, many secondary schools, colleges, and universities, offer a factual course emphasizing the factual data rather than the basic principles. Although teaching chemistry descriptively has appeared adequate in the past, because of the extensive volume of knowledge available today, such a method of instruction seem questionable. More than ever before there seems to be a need for a logical …

A Study Of A Fused Course In Physics And Chemistry For Watertown High School, Gerhart C. Hertz, Merle T. Meinicke

Electronic Theses and Dissertations

The writers had in mind the modification of the present science curriculum in the Watertown High School. In doing this, they sought the answers to the following questions: Can physics and chemistry be fused into a one-year course for pupils who do not enroll in the conventional physics and chemistry classes? Will such a course be feasible and workable? What content will be included? How will it be taught? How will the laboratory work be handled? Can it be adapted to the interests and ability levels of the pupils? Will the achievement of the pupils in this fused course be …

An Evaluation Of The Louisville Course Of Study In Chemistry In Relation To The Educational And Vocational Interests Of Girls As Discovered Among Pupils Of The Louisville Public Schools From September, 1935 To February, 1937., Pauline Kollmann Stein

Electronic Theses and Dissertations

No abstract provided.

The Effect Of Experimental Liver Damage On The Blood Picture Of The Dog., H. D. Bruner

Electronic Theses and Dissertations

No abstract provided.