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Articles 91 - 120 of 1002

Full-Text Articles in Chemistry

Implementation And Assessment Of A Course-Based Undergraduate Research Experience (Cure) In General Chemistry, Alissa Potts Jun 2023

Implementation And Assessment Of A Course-Based Undergraduate Research Experience (Cure) In General Chemistry, Alissa Potts

College of Science and Health Theses and Dissertations

Course-based undergraduate research experiences (CUREs) are growing in popularity in the chemistry community to replace traditional laboratory courses. This approach creates a research experience for a larger number of students than traditional research mentorship experiences offered at universities. CUREs can help students take ownership of projects, learn to design and troubleshoot experimental setups, problem-solve experiments that don’t have a “known answer”, and gain confidence in the laboratory. To assess the effectiveness of a general chemistry laboratory-based CURE course with DePaul students, the Experimental Design Ability Test (EDAT) and the Meaningful Learning in the Laboratory Instrument (MLLI) survey were given to …


A Computational Study Of Adsorptive Desulfurization In Metal Organic Frameworks, Kyle Concha May 2023

A Computational Study Of Adsorptive Desulfurization In Metal Organic Frameworks, Kyle Concha

Theses

Fossil fuel usage has been related to several concerns about the environment and human health. One of these concerns is related to fuels containing Organic Sulfur Compounds (OSCs) which upon burning produce hazardous compounds such as SO2 which contributes to acid rain and affects respiratory health. Removal of these OSCs is an important field of study as it can prevent the production of SOx compounds. One technique to remove OSCs is Adsorptive Desulfurization (ADS) in which Metal Organic Frameworks (MOFs) are potential candidates to be used as adsorbents. Two archetypal MOFs, HKUST-1 and Cu3HHTP2, …


Cooking With Chemistry: Marshmallows, Admin Stem For Success May 2023

Cooking With Chemistry: Marshmallows, Admin Stem For Success

STEM for Success Showcase

This lesson plan teaches students thermodynamics, foam, and other chemistry topics by cooking marshmallows.


New Methods For Core-Hole Spectroscopy Based On Coupled Cluster Theory, Megan Simons May 2023

New Methods For Core-Hole Spectroscopy Based On Coupled Cluster Theory, Megan Simons

Chemistry Theses and Dissertations

X-ray absorption spectra (XAS) is a method used to investigate atomic local structure and electronic states. Coupled cluster method is a numerical method used for describing many-body systems and electron correlation in a wavefunction. When equation-of-motion coupled cluster is used in XAS calculations, the ground state is applied to the excitation operator, which excites or ionizes the electron. This causes a large orbital relaxation error, normally ~5 eV, which leads to the need for triple excitations in order to obtain accurate results.

This dissertation introduces a coupled cluster method that uses "transition potential" reference orbitals to reduce the orbital relaxation …


Design And Synthesis Of Dinucleating Phthalazine-Based Ligands Toward Bimetallic Ruthenium Catalysts For Water Oxidation, Alex Bromley May 2023

Design And Synthesis Of Dinucleating Phthalazine-Based Ligands Toward Bimetallic Ruthenium Catalysts For Water Oxidation, Alex Bromley

Honors Theses

Two synthetic pathways were developed to construct dinucleating ligands towards the synthesis of bimetallic ruthenium-based water oxidation catalysts. The motivation for this work stems from earlier observations of related ligands that are susceptible to oxidative decomposition. The design pursued here incorporates a phthalazine core into the dinucleating ligand, which, we hypothesize, will prevent the previously established cleavage of a pyridazine unit at the same position. The ligand precursors involved in the multi-step syntheses are characterized by Nuclear Magnetic Resonance (NMR) spectroscopy. Synthetic protocols were refined to ensure reproducibility. In addition, our hypothesis for which of the two target ligands will …


Celebrating Native Chemists And Encouraging More Native Talent In Stem, Lisa Villa May 2023

Celebrating Native Chemists And Encouraging More Native Talent In Stem, Lisa Villa

Staff publications

This editorial was written to accompany cover art submitted to the American Chemical Society's 2023 ACS Diversity & Inclusion Cover Art Series, and selected as the July cover for Environmental Science & Technology Letters. The artwork design features several prominent chemists who are also strong advocates for increasing the number of Native American/First Nation scientists. They recognize how cultural beliefs may often be in conflict with scientific conversations, but have been working to attract and encourage Native American talent in the STEM fields.

The published cover art is included as a supplemental file.


Quantitative Analysis Of The Proteomic Selectivity Of Acidic Reductive Alkylation Of Peptides, Connor Jewell May 2023

Quantitative Analysis Of The Proteomic Selectivity Of Acidic Reductive Alkylation Of Peptides, Connor Jewell

Honors Scholar Theses

Proteome quantification is a complicated process which takes on many methods, usually involving peptide derivatization and complex mass spectral analysis. Scores of techniques have been utilized to address issues of incomplete quantification. The implementation of IPTL labeling, or isobaric peptide terminal labeling, is a recent addition to the literature, which exploits the supposedly selective labeling of N-termini of tryptic peptides from the C-termini of lysine residues due to differences in basicity. This method has been shown to improve quantitation by reducing spectral complexity and provide more accurate and reproducible results on peptide abundance. Investigations into the selectivity of terminal derivatization …


Synthesis And Characterization Of Rhenium 2,2′-Pyridylnaphthyridine Metal Complexes, Benjamin F. Solomon Apr 2023

Synthesis And Characterization Of Rhenium 2,2′-Pyridylnaphthyridine Metal Complexes, Benjamin F. Solomon

Honors Theses

Rhenium (Re) is a group 7 heavy 5d transition metal in the same family as manganese (Mn) and technetium (Tc). Re-carbonyl complexes are known to be catalysts for many different kinds of reactions from C-C bond formation to reduction reactions like CO2 reduction (CO2RR)1,2. With this in mind, we have prepared a set of six Re-carbonyl complexes of 2,2′-pyridyl-1,6-naphthyridine (1,6- pynap) and 2,2′-pyridyl-1,8-naphthyridine (1,8-pynap), a redox non-innocent ligand containing a bpy moiety as well as an additional aryl nitrogen binding location at which another metal-ligand bond could form. We have synthesized these complexes as precursors …


Methods For Increasing The Electron Richness Of Iron Tricarbonyl Diimine Complexes, Francesca Lombardi, Joseph Maher, Sean Peloquin Apr 2023

Methods For Increasing The Electron Richness Of Iron Tricarbonyl Diimine Complexes, Francesca Lombardi, Joseph Maher, Sean Peloquin

Chemistry & Biochemistry Student Scholarship

Francesca Lombardi ’24, Major: Chemistry

Joseph Maher ’25, Major: Chemistry

Sean Peloquin ’26, Major: Biochemistry

Faculty Mentor: Dr. Maria Carroll, Chemistry and Biochemistry

The goal of our research is to synthesize new iron complexes that can reduce carbon dioxide. Increasing the electron richness of iron tricarbonyl diimine complexes, which have been synthesized previously in the Carroll research group, will increase the likelihood of a reaction with carbon dioxide occurring. We have taken two approaches to changing the electron density in the complexes. First, we reacted the complex Fe((CF3)2ArDABMe)(CO)¬3 with the reducing agent potassium on graphite, in order to reduce either …


Kinetic Analysis Of Glu115ala Cytosolic Human Malate Dehydrogenase Mutation Shows A Change In Activity On Non-Native Substrate Phenylpyruvate, Kailey Paar Apr 2023

Kinetic Analysis Of Glu115ala Cytosolic Human Malate Dehydrogenase Mutation Shows A Change In Activity On Non-Native Substrate Phenylpyruvate, Kailey Paar

Chemistry & Biochemistry Student Scholarship

The cytosolic human enzyme, malate dehydrogenase (MDH1), is believed to have a significant effect on the proliferation of cancerous cells. This enzyme oxidizes NADH to NAD+ as it converts oxaloacetate (OAA) to malate. This oxidation of NADH provides the needed NAD+ to cancer cells, which require NAD+ as they upregulate glycolysis in aerobic conditions. Targeting MDH1 can reveal new therapeutic treatments for cancer by preventing the conversion of OAA to malate and depleting NAD+ stores in cancer cells, which can be done by mutating residues in the enzyme and assessing the change in activity. Here we show the replacement of …


Magnetic Slime, Admin Stem For Success Apr 2023

Magnetic Slime, Admin Stem For Success

STEM for Success Showcase

Students learn chemistry and physics by making magnetic slime.


Invisible Ink, Admin Stem For Success Apr 2023

Invisible Ink, Admin Stem For Success

STEM for Success Showcase

Students create invisible ink to hide and reveal a message using chemistry.


Sugar Water Density Activity, Admin Stem For Success Apr 2023

Sugar Water Density Activity, Admin Stem For Success

STEM for Success Showcase

In this activity students learn about density using sugar water. Attached is the activity's lesson plan and a teacher reflection on the activity.


Physical And Chemical Changes Lesson Plan, Admin Stem For Success Apr 2023

Physical And Chemical Changes Lesson Plan, Admin Stem For Success

STEM for Success Showcase

Lesson plan and video for an activity on the difference between physical and chemical changes.


The Science Of Baking Bread, Admin Stem For Success Apr 2023

The Science Of Baking Bread, Admin Stem For Success

STEM for Success Showcase

Activity plan to teach biology and chemistry using a lesson on the baking of bread.


Modeling Excited State Processes In Molecular Aggregates By Constructing An Adaptive Basis For The Hierarchy Of Pure States, Leonel Varvelo Apr 2023

Modeling Excited State Processes In Molecular Aggregates By Constructing An Adaptive Basis For The Hierarchy Of Pure States, Leonel Varvelo

Chemistry Theses and Dissertations

Simulating excitation energy transfer (EET) in molecular materials is of crucial importance for the development of and understanding of materials such as organic photovoltaics and photosynthetic systems and further development of novel materials. The Hierarchy of Pure States (HOPS) is an exact framework for the time evolution of an open quantum system in which a hierarchy of stochastic wave functions are propagated in time. The adaptive HOPS (adHOPS) method achieves size-invariant scaling with the number of simulated molecules for sufficiently large aggregates by using an adaptive basis that moves with the excitation through the material. To demonstrate the power of …


Microscale Chemical Manipulation And Imaging Using Photoactive Molecules And Light, Uroob Haris Apr 2023

Microscale Chemical Manipulation And Imaging Using Photoactive Molecules And Light, Uroob Haris

Chemistry Theses and Dissertations

Chemical manipulation with light has been an active and growing area of research with important implications in materials science, biotechnology, and environmental science. From early investigations of light sensitive materials for photography in the 19th century, to printing billions of transistors on a semiconductor chip in present day, scientists have gained a deep understanding of photochemistry and the processes that allow us to harness light for everyday applications. In this work, we explore microscale fabrication and molecular imaging using light and photoactive molecules as foundational tools. We develop a visible-light mediated technique for high resolution microscale chemical lithography comprising …


Exploring Protein Conformations And Functions Through Molecular Dynamics Simulations And Machine Learning, Hao Tian Apr 2023

Exploring Protein Conformations And Functions Through Molecular Dynamics Simulations And Machine Learning, Hao Tian

Chemistry Theses and Dissertations

Proteins are essential biomacromolecules that perform a variety of critical functions in living organisms. The tertiary structure of a protein plays a crucial role in its biological activity as it determines how the protein interacts with other molecules. Consequently, understanding protein conformation and function is an important area of research with implications in medicine, biotechnology, and other fields.

The first part of this dissertation focuses on protein allostery, a process by which proteins transmit perturbations caused by binding at one site to a distal site, thereby regulating activity. With the development of computational methods like molecular dynamics simulations and machine …


Damped Oscillating Phosphoryl Transfer Reaction In The Cyanobacterial Circadian Clock, Hye In Jang, Pyonghwa Kim, Yongick Kim Mar 2023

Damped Oscillating Phosphoryl Transfer Reaction In The Cyanobacterial Circadian Clock, Hye In Jang, Pyonghwa Kim, Yongick Kim

Chemistry Faculty Research

Most organisms have circadian clocks to ensure the metabolic cycle to resonate with the rhythmic environmental changes without “damping,” or losing robustness. Cyanobacteria is the oldest and simplest form of life that is known to harbor this biological intricacy. Its KaiABC-based central oscillator proteins can be reconstituted inside a test tube, and the post-translational modification cycle occurs with 24 h periodicity. KaiC’s two major phosphorylation sites, Ser-431 and Thr-432, become phosphorylated and dephosphorylated by interacting with KaiA and KaiB, respectively. Here, we mutate Thr-432 into Ser to find the oscillatory phosphoryl transfer reaction damps. Previously, this mutant KaiC was reported …


The Concentration Of Heavy Metals In Lincoln Nebraska's Tap Water, Evan Neuhaus Mar 2023

The Concentration Of Heavy Metals In Lincoln Nebraska's Tap Water, Evan Neuhaus

Honors Program: Senior Projects (Public)

Heavy metals are commonplace in nature, and are typically found in scarce quantities in all drinking sources. However, in high enough concentrations, they can have a myriad of negative health effects. This study seeks to find the concentrations of such metals in the Lincoln water supply utilizing the resources of the Water Center at the University of Nebraska at Lincoln. To test for discrete concentrations of trace elements, a method of using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was implemented. ICP-MS uses plasma to ionize and atomize a sample which is then filtered into a series of cones into a …


Principles Of Chemistry-1, Rajnish Singh Feb 2023

Principles Of Chemistry-1, Rajnish Singh

KSU Distinguished Course Repository

Principles of Chemistry, chem 1211, is a 3 credit hour course, the first in a two-semester sequence covering the fundamental principles and applications of chemistry for science majors. Course content includes electronic structure of atoms and molecules, bonding fundamentals, fundamentals of chemical reactions, and gas laws. The course is taught asynchronously and the final exam being a national exam offered by the American chemical society, (ACS), that has to be taken in person.


Geothermal Energy And Its Impacts On The Environment, Aditi Gorthy, Nathan Tran, Laureen Pierre-Louis Jan 2023

Geothermal Energy And Its Impacts On The Environment, Aditi Gorthy, Nathan Tran, Laureen Pierre-Louis

Mako: NSU Undergraduate Student Journal

From the multitude of energy sources that we have developed throughout the eons, renewable energy or “clean energy” has been on the rise to combat global warming and climate change which burning nonrenewable sources of energy have contributed to. Before geothermal energy is used as part of the mainstream energy sources some aspects must be analyzed and resolved. Unfortunately, geothermal power plants still release pollutants, such as carbon dioxide and sulfur dioxide, into the environment and cause general environmental disruptions due to drilling and changes in land formations. Recent and future studies have been and should be conducted to find …


Data Set For "Atmospheric Aging Of Combustion-Derived Particles: Impact On Stable Free Radical Concentration And Its Ability To Produce Reactive Oxygen Species In Aqueous Media", Brian Majestic, Heather L. Runberg Jan 2023

Data Set For "Atmospheric Aging Of Combustion-Derived Particles: Impact On Stable Free Radical Concentration And Its Ability To Produce Reactive Oxygen Species In Aqueous Media", Brian Majestic, Heather L. Runberg

Chemistry and Biochemistry: Data Sets

Environmentally persistent free radicals (EPFR) are an emerging pollutant found in soot particles. Understanding how these change as they move through the atmosphere is important to human health. Here, soot was generated in the laboratory and exposed to simulated sunlight. The concentrations and characteristics of EPFR in the soot was recorded. Additionally, formation of hydroxyl radical from the photoactivated soot was measured.


Green Synthesis Of Nanoparticles And Their Utilization In Electrochemical Detection Of Catechol- Or Phenol-Based Substances, Daniel Laurence Myers Iii Jan 2023

Green Synthesis Of Nanoparticles And Their Utilization In Electrochemical Detection Of Catechol- Or Phenol-Based Substances, Daniel Laurence Myers Iii

Browse all Theses and Dissertations

PART A: GREEN SYNTHESIS OF COPPER NANOPARTICLES AND THEIR UTILIZATION IN THE DETECTION OF NEUROTRANSMITTERS Neurotransmitters, such as dopamine and epinephrine, are chemicals frequently found in the brain and are responsible for a number of human moods, needs, and emotions.1, 2 Detection of such neurotransmitters allows for a better judgement of a person’s physical and mental state, a utility that is vital in determining the presence of disease and mental illnesses.2 Electrochemical detectors used for such detections are often modified by materials such as metal nanoparticles.3 However, synthesizing nanoparticles can involve or produce chemicals, ammonium hydroxide among them, that are …


Lets Make Rock Candy!, Admin Stem For Success Jan 2023

Lets Make Rock Candy!, Admin Stem For Success

STEM for Success Showcase

  • Students should…

    • be familiar with terms such as solubility, solute, solvent, and supersaturated solution.

    • have a basic understanding of crystallization.

    • understand the concept of delayed gratification and how they can practice this skill in their everyday lives to make smart financial decisions.


Paek- And Pes-Like Perarylated Phosphonium Ionenes: Synthesis, Thermal Properties, And Conductivity, Samantha Sims Jan 2023

Paek- And Pes-Like Perarylated Phosphonium Ionenes: Synthesis, Thermal Properties, And Conductivity, Samantha Sims

Murray State Theses and Dissertations

Ionic liquids (ILs) are useful for many applications due to the tunability of their characteristic properties making these salts ideal for many applications. To further increase possible areas of application for these materials, some ILs can be incorporated into polymer structures to form poly ionic liquids (PILs) or ionenes. The specific ions used within the material will determine the thermal, mechanical, and chemical stability properties exhibited by the polymer. Adjustments can be made to the ion structures during the synthetic process to influence these observed properties.

Fuel cells, batteries, solar cells, and capacitors, all require materials that can withstand high …


Development Of Ambient Ionization Mass Spectrometry Approaches For The Characterization And Quantification Of Psychoactive Small-Molecule Constituents In Complex Plant Matrices, Megan Isabella Chambers Jan 2023

Development Of Ambient Ionization Mass Spectrometry Approaches For The Characterization And Quantification Of Psychoactive Small-Molecule Constituents In Complex Plant Matrices, Megan Isabella Chambers

Legacy Theses & Dissertations (2009 - 2024)

Drug chemistry sections of forensic crime laboratories are tasked with analyzing a variety of unknown materials, a subset of which are derived from plants. In comparison to the analysis of small-molecule drugs, these plant matrices are incredibly complex and present unique challenges. When traditional chromatographic approaches are used to interrogate these materials in forensic investigations, large amounts of time, resources, and funds are directed towards the extensive sample preparation steps required. Exacerbating the issue is that the matrix characteristics often result in instrument downtime to accomplish the maintenance required to address ingredients adhering to columns or clogging syringes, which are …


Post-Synthetic Modification Of Metal-Organic Frameworks And Demonstration Of Their Characteristics For Chemistry Education, Audrey Barbara Crom Jan 2023

Post-Synthetic Modification Of Metal-Organic Frameworks And Demonstration Of Their Characteristics For Chemistry Education, Audrey Barbara Crom

Legacy Theses & Dissertations (2009 - 2024)

Metal–organic frameworks (MOFs) have risen in popularity in recent decades due to their applications in gas storage, separations, and catalysis. The vast potential of these materials is a result of the inherent characteristics and properties afforded by the composition and combination of ligand and metal clusters used to construct MOFs. In this dissertation, we explore the properties and capabilities of these frameworks from a variety of perspectives. First, we demonstrate the characteristics of MOFs in experiments designed to be suitable for integration in an educational environment. Inorganic chemistry derives many of its concepts from multiple facets of chemistry, which makes …


Reduced Metal Nanocatalysts For Selective Electrochemical Hydrogenation Of Biomass-Derived 5-(Hydroxymethyl)Furfural To 2, 5-Bis(Hydroxymethyl)Furan In Ambient Conditions, Baleeswaraiah Muchharla, Moumita Dikshit, Ujjwal Pokharel, Ravindranath Garimella, Adetayo Adedeji, Kapil Kumar, Wei Cao, Hani Elsayed-Ali, Kishor Kumar Sadasivuni, Naif Abdullah Al-Dhabi, Sandeep Kumar, Bijandra Kumar Jan 2023

Reduced Metal Nanocatalysts For Selective Electrochemical Hydrogenation Of Biomass-Derived 5-(Hydroxymethyl)Furfural To 2, 5-Bis(Hydroxymethyl)Furan In Ambient Conditions, Baleeswaraiah Muchharla, Moumita Dikshit, Ujjwal Pokharel, Ravindranath Garimella, Adetayo Adedeji, Kapil Kumar, Wei Cao, Hani Elsayed-Ali, Kishor Kumar Sadasivuni, Naif Abdullah Al-Dhabi, Sandeep Kumar, Bijandra Kumar

Chemistry & Biochemistry Faculty Publications

Selective electrochemical hydrogenation (ECH) of biomass-derived unsaturated organic molecules has enormous potential for sustainable chemical production. However, an efficient catalyst is essential to perform an ECH reaction consisting of superior product selectivity and a higher conversion rate. Here, we examined the ECH performance of reduced metal nanostructures i.e., reduced Ag (rAg) and reduced copper (rCu) prepared via electrochemical or thermal oxidation and electrochemical reduction process, respectively. Surface morphological analysis suggests formation of nanocoral and entangled nanowire structure formation for rAg and rCu catalysts. rCu exhibits slight enhancement in ECH reaction performance in comparison to the pristine Cu. However, the rAg …


Chemically Mediated Algal-Bacterial Interactions: Promotion & Inhibition, Kara Talbott Jan 2023

Chemically Mediated Algal-Bacterial Interactions: Promotion & Inhibition, Kara Talbott

University of the Pacific Theses and Dissertations

Algae-bacteria interactions range from mutualistic, Chlamydomonas reinhardtii (green algae) provides carbonate complexes for surface associated bacteria (SAB) and the bacteria in turn provide B-12 for the algae, to pathogenic, the presence of certain bacteria increases the incidence of bleaching in the algae. Algal natural products have been found to display the following activities: anti-fouling, anti-bacterial, anti-cancer, and anti-feedant. Separately, it has been well documented in the literature that algae mediate their SAB, also known as their microbiome, using natural products to attract and inhibit different bacterial strains. My graduate work builds on these findings; our hypothesis is that the algal-bacterial …