Physical Sciences and Mathematics Commons^™

Acetylacetone Oxidation At Room Temperature: A Multiplexed Photoionization Mass Spectrometric Investigation, Study Of The Russell Intermediates In Gas Phase Reactions, And The Investigation Of Oxidation Reaction Products Of Ethanol At Room Temperature, Sara Gallarati

Master's Theses

This thesis presents the combustion study of acetyl acetone using synchrotron radiation coupled with multiplexed photoionization mass spectrometry at 298 K. The experiments were performed at the Chemical Dynamics Beamline 9.0.2 at the Advanced Light Source of the Lawrence Berkeley National Laboratory. The reaction of acetyl acetone with chlorine (Cl) radicals was analyzed based on their photoionization spectra and reaction kinetic profiles.

Additionally, a study of the Russell intermediate has been performed. Previous to experimentation at the Advanced Light Source, computational analysis has been investigated to evaluate compounds that could possibly lead to the formation of a stable species. The …

The Chemistry And Catalytic Activity Of Dehydrogenative Silylation And Hydroboration Of Complexes Bearing Semirigid Ligands With Group 14 Elements, Niroshani S. Abeynayake

Theses and Dissertations

Incorporation of silicon in the ligand backbone would yield electron-rich metal complexes upon coordination to transition metal complexes. The coordination chemistry of semirigid benzyl phosphines bearing a single or multiple phosphorus atoms and varying number of Si−H moieties has gained interest in recent years. This dissertation focuses on synthesizing silyl and germyl transition metal complexes of groups 9 and 10. Chapter II presents the synthesis of a family of four coordinated 14-electron rhodium complexes. The newly synthesized complexes were characterized in solution by multinuclear NMR spectroscopy and in the solid-state by single-crystal X-ray diffraction. These d⁶ complexes possess sawhorse …

Soil From Footwear Is A Newly Rediscovered Type Of Forensic Evidence Due To The Application Of Modern Analytical Techniques : A Review, Rhilynn Haley Ogilvie

Legacy Theses & Dissertations (2009 - 2024)

Traces of soil discovered on a footwear were historically among the first types of evidence used by crime scene investigators. This type of evidence has been rediscovered recently due to the application of powerful analytical techniques providing quantitative characteristics of the soil (bio)chemical composition. Advanced statistical analysis of the quantitative data further improves the probative value of the soil evidence. The article overview main aspects of the emerging techniques for the forensic soil analysis and the factors that challenge data interpretation including mixing, contamination, and composition complexity. Overcoming these issues is crucial for utilizing soil analysis for forensic purposes.

Expanding The Polymer Zwitterion Library – Novel Phosphonium-Based Polymer Zwitterions And Analogous Structures, Marcel U. Brown

Doctoral Dissertations

This dissertation encompasses the synthesis, characterization and application of novel polymer zwitterions that significantly expand the library of available zwitterionic polymers. Their facile synthesis is facilitated by the preparation of a novel functional sultone precursor molecule, which can be ring-opened by commercially available phosphine, amine and sulfide nucleophiles, affording phosphonium, ammonium or sulfonium sulfonate monomers, respectively. Most notably, this work describes the invention of phosphonium-based polymer zwitterions, establishing a new class of zwitterionic polymer structures with unique solution and interfacial properties. Furthermore, the incorporation of these phosphonium sulfonates into block copolymer architectures with conventional polymer zwitterions, and the resulting switchable …

Contra-Thermodynamic Halolactonization Of Lactam-Tethered 5-Aryl-4(E)-Pentenoic Acids For The Flexible And Stereocontrolled Synthesis Of Fused Lactam-Halolactones, Timothy K. Beng, Claire Borg, Morgan J. Rodriguez

All Faculty Scholarship for the College of the Sciences

Halolactonization of alkenoic acids enables the construction of oxygen-heterocycles via intramolecular halonium-induced nucleophilic addition. Although the literature is currently inundated with halolactonizations of 5-aryl-4(E)-pentenoic acids that predictably afford the 6-endo cyclization adducts, methods that reliably alter the innate regioselectivity bias to instead deliver the thermodynamically less favored 5-exo cyclization products are relatively rare. Here, we attempt to bridge this gap and have found mild conditions for contra-thermodynamic halolactonization of lactam-tethered 5-aryl-4(E)-pentenoic acids that lead to the formation of trans-fused lactam-γ-lactones. The natural proclivity for these 5-aryl-4(E)-pentenoic acids to undergo 6-endo cyclization is overridden and 5-exo-trig cyclization predominates. The success of …

Sulfur Behavior In The 1257 Ce Samalas Magma (Lombok, Indonesia) As Revealed By Volcanic Apatite, Yasmin Jackson

Earth Sciences Theses and Dissertations

Explosive volcanic eruptions can inject massive amounts of volatiles, including SO₂ and H₂S, into the stratosphere, inducing drastic tropospheric cooling via sulfate aerosols. Greenland and Antarctic ice cores record evidence of these substantial releases of SO₂ and H₂S, including the massive release during the ultraplinian 1257 CE Samalas eruption. The 1257 CE Samalas eruption is estimated to have released ~158 Tg of SO₂, making it the largest volcanogenic release of SO₂ within the last 2000 years. Vidal et al. (2016) propose that most of this sulfur (S) was hosted in a …

Comparing Computational Methods By Stretching Diatomic Molecules, Aaron Mitchell

Undergraduate Student Research Internships Conference

A comparison of functionals was done by comparing full electron density profiles along the bond axis of H₂ and N₂. Additionally, based on the success of the (HF)-DFT method, the goal of this project was to compare the mRKS method to (HF)-DFT.

Assessment Of The Toxicity Of Legacy And Next-Generation Perfluoroalkyl Substances (Pfas) In Early-Life Stages Of Freshwater And Marine Fish, Kiflom Gebreab

FIU Electronic Theses and Dissertations

Per- and polyfluoroalkyl substances (PFASs) are a group of synthetic surfactants that have utilized for several decades in a wide range of industrial and manufacturing applications. Owing to their high chemical stability, PFAS are widespread and persistent in the environment, and have been shown to be bioaccumulative in diverse organisms including plants, wildlife, and humans. Exposure to PFASs has been linked to a range of documented toxic and/or adverse effects in relation to human and animal health. The potential environmental health and ecotoxicity of next-generation PFAS remain unclear. In the present study, toxicity, and bioconcentration potential, of several perfluoroether carboxylic …

Stereocontrolled Access To Δ-Lactone-Fused-Γ-Lactams Bearing Angular Benzylic Quaternary Stereocenters, Timothy K. Beng, Morgan J. Rodriguez, Claire Borg

All Faculty Scholarship for the College of the Sciences

C-fused γ-lactam-lactones are resident in several bioactive molecules, including anticancer agents such as omuralide. In this embodiment, we report mild conditions for the catalytic halolactonization of lactam-tethered 5-aryl-4(E)-pentenoic acids. The use of dichloromethane as the solvent and Ph₃PS as the catalyst led to predominant 6-endo-trig cyclization and furnished the trans-fused-γ-lactam-δ-lactones. The transformation is modular, regioselective, chemoselective, and diastereoselective. The γ-lactam-δ-lactones bear angular quaternary benzylic stereocenters, which is noteworthy since the presence of a quaternary carbon in bioactive small molecules often promotes an element of conformational restriction that imparts potency, selectivity, and metabolic stability. The …

Targeting Heat Shock 27 Kda Protein Induces Androgen Receptor Degradation, Yaxin Li

ETD Archive

Glioblastoma (GBM) is the most common and aggressive brain tumor, with very poor prognosis. Androgen receptor (AR) plays a significant role in the progression of GBM, and anti-androgen agents have the potential to be used for the treatment of GBM. However, AR mutation commonly happens in GBM, which makes the anti-androgen agents less effective. Heat shock 27 kDa protein (HSP27) is a well-documented chaperone protein to stabilize AR. Inhibition of HSP27 results in AR degradation regardless the mutation status of AR, which makes HSP27 a good target to abolish AR in GBM. Identified compound I ((N-(3-((2,5-dimethoxybenzyl)oxy)-4-(methylsulfonamido) phenyl)-4-methoxybenzamide) inhibits GBM cell …

Dr. Lawrence J. Berliner, Anit Tyagi

DU Undergraduate Research Journal Archive

An interview with Dr. Lawrence J. Berliner.

Prediction And Confirmation Of A Switch-Like Region Within The N-Terminal Domain Of Hsirt1, Angelina T. Huynh, Thi-Tina N. Nguyen, Carina A. Villegas, Saira Montemorso, Benjamin Strauss, Richard A. Pearson, Jason G. Graham, Jonathan Oribello, Rohit Suresh, Brooke Lustig, Ningkun Wang

Faculty Research, Scholarly, and Creative Activity

Many proteins display conformational changes resulting from allosteric regulation. Often only a few residues are crucial in conveying these structural and functional allosteric changes. These regions that undergo a significant change in structure upon receiving an input signal, such as molecular recognition, are defined as switch- like regions. Identifying these key residues within switch-like regions can help elucidate the mechanism of allosteric regulation and provide guidance for synthetic regulation. In this study, we combine a novel computational workflow with biochemical methods to identify a switch-like region in the N-terminal domain of human SIRT1 (hSIRT1), a lysine deacetylase that plays important …

Computational Investigations Into Astrochemical Inorganic Oxides, Ammonia Borane, And Genetic Algorithms, E. Michael Valencia

Honors Theses

The formulations of quantum mechanics in the early 1900s were exciting theoretical discoveries, but were not practical to apply until the advent of computers and the subsequent computational methods in 1951. With the introduction of tractable simplifications, procedures such as Hartree-Fock allowed for determination of properties of non-trivial systems. Presently, huge leads of computational power have allowed for extremely precise, quantitative work that can be applied to the human body, synthesis, or even astrochemical processes. This thesis presents works concerning 1) the history of quantum mechanics; 2) a brief primer on computational chemistry and its methods; 3) inorganic oxides in …

Stem Club, Camden Jones, Erica Gesner, Amber Gadeken

Honors Expanded Learning Clubs

The goal of this club is to introduce various topics stemming from different fields in science. We hope to excite the students about science and show them how important it is to their everyday lives. This club also aims to provide free education to underserved communities.

Hierarchical Modelling Of Raman Spectroscopic Data Demonstrates The Potential For Manufacturer And Caliber Differentiation Of Smokeless Powders, Nathan Russell Bartlett

Legacy Theses & Dissertations (2009 - 2024)

With the rise of gun-based crime and the advent of lead-free ammunition reducing the effectiveness of previously used methods, the analysis of smokeless powders to better understand organic gunshot residues is now more important than ever. One method that has shown potential is Raman spectroscopy, a relatively quick, nondestructive, and non-contact analysis method. To investigate whether Raman spectroscopy could be used to characterize individual powders, samples of smokeless powders from three manufacturers, Remington, Federal, and Winchester, each with two 9mm caliber and two .38 caliber ammo types, were dissolved, and their Raman spectra were collected. A hierarchical modelling system was …

Exploring Indicator Displacement Assays For Phosphate Detection In Seawater, Francis Radics

Chemistry & Biochemistry Student Scholarship

Francis Radics ’22
Major: Biochemistry
Faculty Mentor: Dr. John Breen, Chemistry and Biochemistry

Indicator displacement assays are based on the optical signal modulation of a noncovalently bound indicator upon dissociation by an analyte species. Our work has focused on exploring the lower detection limits for luminescent displacement assays for inorganic phosphate in seawater using complex ions containing two di(2-picolyl)amine ligands (also called DPA or bis(2-pyridylmethyl)amine), each coordinating a zinc cation. Following the work of B.D. Smith and coworkers, we have prepared three ligands by covalently attaching two DPA moieties, 2,6-bis(chloromethyl) benzene, and 2,6-bis(chloromethyl)-4-methylphenol, and 1,2-phenylenedimethylamine, for assays with 6,7-dihydroxy-4-methanesulfonic acid …

The Effects Copper Has On Casting Glass, K. Malika Haver

Honors Projects

The aim of this honors project was to discern the difference between how various types of copper reacted with glass. The two disciplines that were connected were chemistry and glassblowing. The basic components learned in chemistry were applied to glass with an end goal of a project installation that visualized the discoveries with copper. The glassblowing technique used was lost wax casting, and the two types of copper used were copper foil and fine copper metal powder. The copper was found to turn the glass into various blues with the intensity and darkness of the blues being dependent on the …

Metal Complexes Of Redox Active Ligands, Alexandra Chaparro, Parker Keller

Chemistry & Biochemistry Student Scholarship

Alexandra Chaparro ’22, Major: Biochemistry

Parker Keller ’24, Major: Chemistry

Mentor: Dr. Maria Carroll, Chemistry and Biochemistry

Our research focuses on synthesizing and studying the properties of metal complexes that contain redox active ligands. Ligands are molecules or ions that can bind to a metal ion, and this particular class of ligands is interesting because they can either accept or lose electrons. We synthesized zinc complexes, in order to measure the reduction potentials of the ligands, which provide information about the ease with which they accept electrons. We then synthesized iron complexes and determined their structures. These complexes are potentially …

Fast Photochemical Oxidation And Footprinting Of Proteins Via Trifluoromethyl Radical Chemistry, Elaine Morrow

Honors Theses

Fast photochemical oxidation of proteins (FPOP) is a useful tool in proteomics because of the ability for modifications to occur on the scale of microseconds which reduces the modifications to tertiary and quaternary structure allowing for more accurate labeling of the protein. Labels for FPOP are generated from various radicals in our experiments which include hydroxyl radicals and trifluoromethyl radicals. Hydroxyl radicals are easily generated by using an excimer laser (KrF laser, 248 nm) or a UV flash lamp (as a part of the Fox™ System) by the photolysis of hydrogen peroxide. Trifluoromethyl radicals, however, need hydroxyl radicals to be …

Applied Math In Introductory Chemistry, Ji Kim, Grace Pai

Open Educational Resources

Students, particularly those who are non-science majors, often struggle with college-level science courses required for graduation due to the applied mathematics needed to successfully complete the course. This resource includes four activities on the topics of units and measurements, dimensional analysis, density, and gases. These topics were specifically designed to teach the mathematics embedded in these topics in a culturally responsive way. Throughout the activities, we incorporate these four elements of culturally relevant pedagogy (Ladson-Billings, 2009) in order to engage students in successfully solving basic mathematics in chemistry while promoting their interest in learning chemistry.

Biochemical Characterization Of Induced Pluripotent Stem Cell-Derived Cardiomyocytes As A Model Of Barth Syndrome, Alisha J. House

ETD Archive

Barth Syndrome (BTHS) is an X-linked inborn error of metabolism (IEM) which manifests as a multi-systemic disease. One of the primary symptoms is dilated cardiomyopathy, and alongside the cardiovascular disease that arises, patients often experience metabolic abnormalities such as 3-methylglutaconic aciduria, growth retardation, and neutropenia. There has been a need for the development of a suitable in vitro modeling system which will accurately recapitulate the biochemical and physical nature of BTHS. The purpose of this project has been to develop a model for studying the biochemical pathogenesis of Barth Syndrome using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). To achieve …

Unraveling Molecular Mechanisms Of Antibiotic Resistance Through Multiscale Simulations And Explainable Machine Learning, Zilin Song

Chemistry Theses and Dissertations

Pathogen resistance to β-lactam antibiotics compromises effective treatments of superbug infections. One major source of β-lactam resistance is the bacterial production of β-lactamases, which could effectively hydrolyze β-lactam drugs. In this thesis, the hydrolysis of various β-lactam antibiotics by class A serine-based β-lactamases (ASβLs) were investigated using hybrid Quantum Mechanical / Molecular Mechanical (QM/MM) minimum energy pathway (MEP) calculations and explainable machine learning (ML) approaches. The TEM-1/benzylpenicillin acylation reaction with QM/MM chain-of-states reaction pathways was firstly revisited. I proposed two decomposition methods for energy contribution analysis based on perturbing ML regression models. Both methods were shown to be model implementation …

A Damaged Reputation: Nuclear Depictions In Entertainment Media, Alexander Cannon

Chemistry & Biochemistry Student Scholarship

This paper, originally written for Dr. Adamus Liotta in an honors chemistry class, explores the possibility of a significant influence over public common sense found in the depictions of entertainment media. Through careful analysis and interpretation of Godzilla, The Simpsons, Fallout, and Call of Duty, this paper finds a synergy throughout this diverse range of audience, medium and historical origin, which culminates in an effect much greater than the sum of its parts. This effect frames nuclear science, of any kind, in a hyperbolically catastrophic and horrific light, reinforcing an excessively cautious, pessimistic public perspective on nuclear technology …

Synthesis Of Phosphonate-Based Diimide Ligands, Kenya V. Medina, Adelani Pius

Honors Program Theses and Research Projects

There has been a resurged interest in the synthesis of metal-organic frameworks because of their potential applications in energy production and drug delivery. Although diimides are insoluble in aqueous solutions, the addition of phosphonic acid allows the complex to be water soluble, which greatly increases their application. Therefore, the creation of a hybrid metal-organic complex by the addition of phosphonic groups to diimide ligands can result in a polar porous compound. In this project the ligand design included the use of dianhydrides including pyromellitic dianhydride, naphthalenetetracarboxylic dianhydride, perylenetetracarboxylic dianhydride, and biphenyl-tetracarboxylic acid dianhydride. These dianhydride precursors were refluxed under argon …

Strategic Consideration And Recommendation On Development Of Chemistry In China, Yanlin Cheng, Shuxian Wu, Qing Dai, Chunying Chen, Yuliang Zhao

Bulletin of Chinese Academy of Sciences (Chinese Version)

Chemistry, as a central science linking all the other sciences, has played an influential role in promoting the development of the whole scientific and technological field and the prosperity of economy and society. Developed countries strongly support the development of chemistry and effectively promote the level of chemical research and chemical industry. Since the founding of the People's Republic of China, chemical research has been supported among the field of natural sciences, and its current level is at the forefront of the world. However, there are still problems in the field of chemistry research in China, such as insufficient major …

Evaluation And Improvement Of Capillary Microextraction Of Volatiles Coupled To Gas Chromatography-Mass Spectrometry For The Analysis Of Ignitable Liquid Residues In Fire Debris, Michelle Nikole Torres

FIU Electronic Theses and Dissertations

A key aspect of fire debris analysis is the ability to extract the remnants of an ignitable liquid from a matrix with a high degree of reliability and sensitivity. Although there are several robust, standardized methods, there is no single technique universally applicable to casework. In this work a novel extraction technique – Capillary Microextraction of Volatiles (CMV) – has been applied, for the first time, for ignitable liquid residue (ILR) extraction. A 20-minute dynamic sampling laboratory protocol from traditional 1 L paint cans was established and optimized based upon ASTM guidelines. The development of new adsorption phases for CMV …

P3k14c, A Synthetic Global Database Of Archaeological Radiocarbon Dates, Erick Robinson

Anthropology Faculty Publications and Presentations

Archaeologists increasingly use large radiocarbon databases to model prehistoric human demography (also termed paleo-demography). Numerous independent projects, funded over the past decade, have assembled such databases from multiple regions of the world. These data provide unprecedented potential for comparative research on human population ecology and the evolution of social-ecological systems across the Earth. However, these databases have been developed using different sample selection criteria, which has resulted in interoperability issues for global-scale, comparative paleo-demographic research and integration with paleoclimate and paleoenvironmental data. We present a synthetic, global-scale archaeological radiocarbon database composed of 180,070 radiocarbon dates that have been cleaned according …

Adapting The Cacao Model To Support Higher Education Stem Teaching Reform, Karen Viskupic, Brittnee Earl, Susan E. Shadle

Geosciences Faculty Publications and Presentations

Background: Efforts to achieve improved student outcomes in STEM are critically reliant on the success of reform efforts associated with teaching and learning. Reform efforts include the transformation of course-based practices, community values, and the institutional policies and structures associated with teaching and learning in higher education. Enacting change is a complex process that can be guided by change theories that describe how and why a desired change takes place. We analyzed the utility of a theory-based change model applied in a higher education setting. Our results provide guidance for change efforts at other institutions.

Results: Use of the CACAO …

Harmful Algal Blooms In Caesar Creek Lake And Their Relationship To Riparian Cover, Morgan C. Grunden

Browse all Theses and Dissertations

Caesar Creek Lake (CCL) in Warren County, OH has recently been experiencing harmful algal blooms (HABs) which are most likely attributed to an excess of phosphorus (P) from fertilizers and manures applied to surrounding fields. Sediments act as a sink for P later supplying a source of P in lakes for HABs when waters become thermally stratified and anoxic. This study seeks to determine the relationship between HABs in CCL and riparian cover at the main tributaries, Anderson Fork and Caesar Creek. In order to do this, sediment samples were collected from four sample sites along Anderson Fork and three …

Measurements Of Atmospheric Radicals, Heather L. Runberg

Electronic Theses and Dissertations

Atmospheric particulate matter (PM) is a global health concern. PM_2.5 is formed primarily through combustion processes such as automobile use and industrial activity. Natural sources of PM_2.5 result from events like volcanos and wildfires. Upon inhalation, PM_2.5 is small enough to travel deep into the lungs where it can form reactive oxygen species (ROS), such as hydroxyl radical (OH), causing oxidative damage to pulmonary tissues. PM_2.5 has been linked to cardiopulmonary diseases such as asthma, chronic obstructive pulmonary disease (COPD), and high blood pressure.

PM_2.5 is small enough to remain aloft and travel many hundreds …