Chemistry Commons^™

Virginia Academy Of Science At 100: A Presentation Given To The Chemistry Section Of The Virginia Academy Of Science, Tom Devore

Virginia Journal of Science

While I have not been an active member of the Virginia Academy of Sciences (VAS) for all of its 100 years of existence, I have seen many changes in VAS during the more than 30 years that I have been an active member. This paper, delivered at the VAS Annual Meeting at the College of William and Mary on May 25, 2023, recalls some of the outstanding scientists in Virginia that I have had the privilege of knowing and who have led and lived out the goals of VAS. They inspired me to try to live up to the high …

Characterizing And Developing Chemistry Students’ Data Analysis And Interpretation Of Chemical Data, Stephanie A. Berg

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

All chemistry students must develop competency in analyzing and making sense of data. However, there are many difficulties that chemistry students may experience while analyzing data. Many students may not use relevant prior knowledge to aid in making sense of data, or they may not form conclusions using all the data provided. Additionally, prior knowledge seems to influence one’s data analysis, but little is known about how students use it to make sense of data. Thus, I interviewed undergraduate students as they analyzed graphical data for a task and characterized how they used their prior knowledge throughout. My findings suggest …

Shorting At Long Duration: Impact Of Extended Discharge Capacity On Battery Solid Electrolytes, Ryan C. Hill, Amanda S. Peretti, Leo J. Small, Erik D. Spoerke, Yang-Tse Cheng

Chemical and Materials Engineering Faculty Publications

Long-duration energy storage (LDES) is critical to a stable, resilient, and decarbonized electric grid. While batteries are emerging as important LDES devices, extended, high-power discharges necessary for cost-competitive LDES present new materials challenges. Focusing on a new generation of low-temperature molten sodium batteries, we explore here unique phenomena related to long-duration discharge through a well-known solid electrolyte, NaSICON. Specifically, molten sodium symmetric cells at 110 ° C were cycled at 0.1 A cm−2 for 1–23 h discharges. Longer discharges led to unstable overpotentials, reduced resistances, and decreased electrolyte strength, caused by massive sodium penetration not observed in shorter duration discharges. …

The Dynamics Of The Flavin, Nadph, And Active Site Loops Determine The Mechanism Of Activation Of Class B Flavin-Dependent Monooxygenases, Gustavo Pierdominici-Sottile, Juliana Palma, María Leticia Ferrelli, Pablo Sobrado

Chemistry Faculty Research & Creative Works

Flavin-dependent monooxygenases (FMOs) constitute a diverse enzyme family that catalyzes crucial hydroxylation, epoxidation, and Baeyer–Villiger reactions across various metabolic pathways in all domains of life. Due to the intricate nature of this enzyme family's mechanisms, some aspects of their functioning remain unknown. Here, we present the results of molecular dynamics computations, supplemented by a bioinformatics analysis, that clarify the early stages of their catalytic cycle. We have elucidated the intricate binding mechanism of NADPH and L-Orn to a class B monooxygenase, the ornithine hydroxylase from (Formula presented.) (Formula presented.) known as SidA. Our investigation involved a comprehensive characterization of the …

Accurate Characterization Of Binding Kinetics And Allosteric Mechanisms For The Hsp90 Chaperone Inhibitors Using Ai-Augmented Integrative Biophysical Studies, Chao Xu, Xianglei Zhang, Lianghao Zhao, Gennady M. Verkhivker, Fang Bai

Mathematics, Physics, and Computer Science Faculty Articles and Research

The binding kinetics of drugs to their targets are gradually being recognized as a crucial indicator of the efficacy of drugs in vivo, leading to the development of various computational methods for predicting the binding kinetics in recent years. However, compared with the prediction of binding affinity, the underlying structure and dynamic determinants of binding kinetics are more complicated. Efficient and accurate methods for predicting binding kinetics are still lacking. In this study, quantitative structure–kinetics relationship (QSKR) models were developed using 132 inhibitors targeting the ATP binding domain of heat shock protein 90α (HSP90α) to predict the dissociation rate …

A Single Hydrogen Bond That Tunes Flavin Redox Reactivity And Activates It For Modification, Debarati Das, Anne-Frances Miller

Markey Cancer Center Faculty Publications

Electron bifurcation produces high-energy products based on less energetic reagents. This feat enables biological systems to exploit abundant mediocre fuel to drive vital but demanding reactions, including nitrogen fixation and CO₂ capture. Thus, there is great interest in understanding principles that can be portable to man-made devices. Bifurcating electron transfer flavoproteins (Bf ETFs) employ two flavins with contrasting reactivities to acquire pairs of electrons from a modest reductant, NADH. The bifurcating flavin then dispatches the electrons individually to a high and a low reduction midpoint potential (E°) acceptor, the latter of which captures most of the energy. Maximum efficiency …

The Study Of Biomass Based Polymers And Cyclic Polymers, Yishayah Bension

Theses and Dissertations

Plastics have become an integral part of everyday life, from household care to aerospace applications, polymers are involved in every industry. Most of these polymeric materials are derived from petroleum feedstocks which have deleterious effects on our environment. The production of petrochemicals has led to an increase in greenhouse gases and microplastic pollution which have accelerated climate change. My research focuses on utilizing existing biomasses to improve the plastic economy’s circularity. This work develops new materials from bio-based polymers such as lignin and soybean oil. Raw lignin suffers from inherently weak mechanical properties, poor solubility, processability, and molecular structure ambiguity. …

Diagnosing Discharge Events Within A Novel Miniature Simplified Coaxial Ion Trap Mass Analyzer, David Virgil Sirbescu-Stanley

Masters Theses

Mass spectrometry is a technique that organizes material samples by mass to reveal their chemical composition by forming a spectrum. Since their invention, ion trap mass spectrometers have undergone significant enhancements. This work, funded by the National Science Foundation and in collaboration with Brigham Young University, the Simplified Coaxial Ion Trap (SCIT), attempts to simplify ion trap geometry and combine three ion traps into one device. Successful demonstration of the SCIT functionality could reduce costs, reduce manufacturing complexity, and shrink total instrument volume. At the same time, trapping capacity and analytical efficiency will be increased. However, as discussed within, challenges …

Investigating Ocean Carbonate System Changes Across Latitudes In The North Atlantic Basin With A Time-Series Mooring System, Anna Trujillo

Independent Study Project (ISP) Collection

The world ocean, specifically the Arctic, serves as one of the greatest mitigators for anthropogenic carbon dioxide release, making the study of high latitude ocean carbonate chemistry an increasingly important topic. While much work has been done concerning the science of acidification and future model projections, analyzing data to detect decadal anthropogenic trends and effects is also highly important. Aiming to add to this data pool, this study investigated the ocean carbonate system at three North Atlantic mooring locations at polar, subtropical, and tropical latitudes from 2013 - 2021. Time series datasets of the pH and pCO₂ of surface water …

Self-Assembly Of Core-Substituted Naphthalene Diimide Based Palladium (Ii) And Platinum (Ii) Macrocycles, Samantha Aragon, Camille Kwan, Franchesca Tinacba

Posters - 2024

Coordination-driven self-assembly is an efficient way to create 2D and 3D supramolecular coordination complexes (SCC) due to its predictable features of metal coordination. SCC’s represent a growing area of research with applications in various fields such as host-guest chemistry, catalysis, chemical transfer and separation, and stabilization of its reactive intermediate. Integrating various fluorophore/chromophore into these SCC’s results in unique properties and functions. In this project, core-substituted naphthalenediimide (NDI) based macrocycles were constructed via self-assembly with 90° platinum (II) and palladium (II) phosphane triflates.1H NMR and 31P NMR studies of the self-assembled product in various nonpolar to polar solvents showed two …

Magnetic Properties And Biological Relevance Of Scorpionate-Based Transition Metal Complexes, Laxmi Devkota

Dissertations (1934 -)

There are two major components to this research dissertation. The first component describes the synthesis and characterization of high-spin, first-row transition metal complexes supported by facially-coordinating “scorpionate” ligands. These studies have sought to uncover fundamental relationships between molecular structure and magnetic properties, with the ultimate aim of assisting in the design of single molecule magnets (SMMs). To this end, comprehensive series of four and five-coordinated M(II)-X complexes (M = Co, Fe, and Cu; and X = F, Cl, Br, and I) were prepared using hydrotris(pyrazol-1-yl)borate ligands (TpR,R’; where R and R’ indicate substituents at the 3- and 5-position of the …

Elucidating The Effect Of Surface Modifications On Nanomaterial Function, Nicholas Langer

Dissertations (1934 -)

Nanoparticles (NPs) are an exciting class of materials with unique properties that inspire their use in sensing, catalysis, optoelectronic devices, and more. NPs are frequently coated in organic molecules, termed ligands, to increase their stability, but ligands also influence NP catalytic activity and their interactions with neighboring molecules. To fully realize the potential of nanomaterials as key components in novel complex systems, a more nuanced understanding of the relationships between NPs, ligands, and their surrounding microenvironment is critical. After a brief review of the NP field in Chapter 1, Chapter 2 begins the investigation of structure-function relationships with a cross-class …

Probing Charge Transport Mechanisms In 2d Semiconductive Metal Organic Framewoks, James Nyakuchena

Dissertations (1934 -)

Metal organic frameworks (MOFs) are a class of highly porous crystalline materials constructed from metal nodes connected by multitopic organic ligands. Due to their unique properties such as large surface area, tunable pore structure, and structural diversity, they have demonstrated potential in a wide array of applications including gas storage and separation, sensing, catalysis, and drug delivery. However, there are only a handful of MOFs reported that have electrical conductivity, which prevents their applications in photoelectronic and photocatalytic applications. This is because hard metals and redox inactive ligands with terminal hard linking bases such as carboxylates are often used in …

Thinking Outside The Membrane: Investigating The Structure Of The Influenza A M2 Ectodomain, Kyra Roepke , '24

Senior Theses, Projects, and Awards

Influenza A leads to annual epidemics that result in three-to-five million cases of severe illness each year and occasional devastating pandemics. Some current prevention and treatment methods target the M2 membrane protein on the surface of the virus. However, viral mutability and drug resistance require the targeting of more conserved parts of the protein.

The goal of this thesis was to investigate the secondary structure and dynamics of the M2 ectodomain (M2e), which is highly conserved across influenza viruses and across evolutionary time. The structure of M2e has previously been challenging to study because of its flexibility. In this study, …

Differences In The Metabolic Outputs Of Caulobacter Crescentus Modify The Kinetics Of Silver Nanoparticle Dissolution, Tyler M. Hicks , '24

Senior Theses, Projects, and Awards

Silver nanoparticles (AgNPs) are widely used within commercial products due to their distinct antibacterial and antimicrobial properties. As their utilization continues to increase, their inevitable improper disposal could present lasting environmental ramifications due to their nonspecific biotoxicity. One microorganism of interest is Caulobacter crescentus, a common freshwater bacterium found in locations where AgNPs end after their disposal. C. crescentus has two distinct cell types—a stalked and a swarmer form—each with their own unique function and metabolic outputs. Approximately 15% of the C. crescentus metabolome varies with cell cycle, thus making this an interesting and environmentally relevant model organism for …

Multifunctional Nanomaterial Analysis Using Inexpensive Techniques, Casey Jordan , '24

Senior Theses, Projects, and Awards

Designing methods to comprehensively understand nanomaterial interactions is of paramount importance as nanomaterials gain widespread use and their environmental impact becomes a concern. While current characterization methods are suitable for initial assessments, there is a need for comprehensive techniques to evaluate end-of-use scenarios and environmental effects. This report emphasizes the potential of electrochemistry as a versatile measurement tool for nanomaterial analysis. Two projects are presented, showcasing innovative analytical architectures to overcome the limitations of existing techniques. Project 1 integrates linear sweep stripping voltammetry (LSSV) and particle impact voltammetry (PIV) to achieve kinetic resolution and size analysis of silver nanoparticles (AgNPs) …

Analyzing The Influence Of Design And Operating Conditions On Combustion And Emissions In Premixed Turbulent Flames: A Comprehensive Review, Medhat Elkelawy Prof. Dr. Eng., E. A. El Shenawy Prof. Dr., Hagar Alm-Eldin Bastawissi, Ibrahim Ali Mousa Eng., Mohamed M. Abdel-Raouf Ibrahim Dr. Eng.

Journal of Engineering Research

Recently, premixed combustion has dominated the field of combustion research worldwide. The current work is a review that addresses the effects of design and operating regimes on the combustion and emission characteristics of premixed turbulent flames. The study accounts for recent developments aimed at overcoming combustor operability issues that influence emissions and flame stability. Various experimental setups have been utilized in investigations, with results pertaining to performance and emissions concerning premixed turbulent flames. Thus, the objective of this paper is to provide a comprehensive review of the effects of swirl vane angles and equivalence fuel-air ratios for tests conducted both …

Accurate Estimation Of Ethanol Content In Fruit Juices Using Cielab Color Space And Chemometrics Via Smartphone-Based Digital Image Colorimetry, Chairul Ichsan, Yasir Amrulloh, Desti Erviana

Makara Journal of Science

This study aims to investigate the optimal color space and chemometric technique for digital image colorimetry to determine ethanol content (% v/v) in apple, orange, and grape juices, using potassium dichromate (K₂Cr₂O₇) under acidic conditions. The accuracy of colorimetric–chemometric integration across various color spaces (RGB, HSV, CIELab, CMYK, CIELuv, CIEXYZ, and CIELch) was benchmarked against UV–Vis spectrophotometry using metrics such as coefficient of determination (R²), mean absolute percentage error (MAPE), and root–mean–squared error (RMSE). Various chemometric techniques (PLS, PCR, MLR, multivariable–SVR, and multivariable NN regression) were evaluated. Results demonstrate that combining the CIELab color …

An Exploration Of Secondary School Science Teacher’S Epistemological Belief In Malang, Anindyta Nur Rizkyana Safitri, Endang Purwaningsih, Nuril Munfaridah, Alif Darmawan

Jurnal Pendidikan Sains

The objective of this study is to delve into the epistemological convictions of secondary school science teachers in Malang across various tenures, namely senior teachers, junior teachers, and pre-service teachers. Employing an explanatory sequential design model, the research employs a mixed-method approach. Quantitative data, gathered through the administration of the Scientific Epistemology Beliefs Questionnaire (n = 30), are complemented by qualitative insights drawn from interviews with teachers (n = 6) concerning their epistemological orientations. Descriptive statistics and qualitative analyses, utilizing an a priori coding technique aligned with the study’s conceptual framework, were conducted on the interview data. Quantitative analysis reveals …

Myeloid-Derived Suppressor Cell Mitochondrial Fitness Governs Chemotherapeutic Efficacy In Hematologic Malignancies, Saeed Daneshmandi, Jee Eun Choi, Qi Yan, Cameron R. Macdonald, Manu Pandey, Mounika Goruganthu, Nathan Roberts, Prashant K. Singh, Richard M. Higashi, Andrew N. Lane, Teresa W-M Fan, Jianmin Wang, Philip L. Mccarthy, Elizabeth A. Repasky, Hemn Mohammadpour

Markey Cancer Center Faculty Publications

Myeloid derived suppressor cells (MDSCs) are key regulators of immune responses and correlate with poor outcomes in hematologic malignancies. Here, we identify that MDSC mitochondrial fitness controls the efficacy of doxorubicin chemotherapy in a preclinical lymphoma model. Mechanistically, we show that triggering STAT3 signaling via β2-adrenergic receptor (β2-AR) activation leads to improved MDSC function through metabolic reprogram- ing, marked by sustained mitochondrial respiration and higher ATP generation which reduces AMPK signaling, altering energy metabolism. Furthermore, induced STAT3 signaling in MDSCs enhances glutamine consumption via the TCA cycle. Metabolized glutamine generates itaconate which downregulates mitochondrial reactive oxygen species via regulation of …

Fostering Engagement And Learning Outcomes: A Comparative Analysis Of Ethnochemical And Stem-Based Pedagogies For Chemistry Learning In Vocational High Schools, Maulidya Husnul Khatimah, Lismi Animatul Chisbiyah

Jurnal Pendidikan Sains

In contemporary education, the perceived difficulty of learning chemistry, attributed to its abstract nature, remains a challenge for many students. This difficulty is compounded by a notable lack of alignment between chemistry concepts and students’ daily experiences, despite the inherent relevance of chemistry to their everyday phenomena. Building on previous research affirming the efficacy of ethnochemical modules in enhancing student learning and achievement, this study investigates the suitability of a STEM-based approach for chemistry education, particularly in vocational high school. The research methodology employs a literature study method, utilizing the PICO(T) framework for keyword selection. A rigorous review and analysis …

Differences In Biology Students’ Self-Regulation During Online And Offline Learning And Its Relationship To Learning Outcomes, Adi Kus Rochman Jk, Dwi Listyorini, Fatchur Rohman, Yessi Affriyenni

Jurnal Pendidikan Sains

The cultivation of self-regulatory skills holds paramount importance for individuals’ future success, particularly in the context of evolving educational modalities prompted by the Covid-19 pandemic. As learning transitions between online during the pandemic and offline post-pandemic, understanding the nuances of self-regulation becomes imperative. Thus, this study sought to achieve three objectives: (1) analyzing disparities in student self-regulation between online and offline settings, (2) examining the interplay between online and offline self-regulation, and (3) scrutinizing the relationship between self-regulation and learning outcomes. Employing a methodological approach involving questionnaire administration, interviews, and collecting academic scores data, data analysis was conducted utilizing the …

Can Argument-Driven Inquiry-Assisted Virtual Laboratory Improve Pre-Service Physics Teachers’ Mastery Concept Of Simple Harmonic Oscillation?, Yolanda Dwi Vivian Karawahenni, Sutopo Sutopo, Arif Hidayat, Maya Mustika

Jurnal Pendidikan Sains

This study endeavors to ascertain the efficacy of the Argument-Driven Inquiry (ADI)- assisted virtual laboratory learning model in enhancing the comprehension of simple harmonic oscillation concepts among pre-service physics teachers. Employing a mixed- method approach with an embedded experimental design, the investigation employs a reasoned multiple-choice instrument comprising 15 questions. Analysis of the results reveals a noteworthy 48.38% increase in the average mastery of concepts between the pre-test and post-test, yielding an N-gain value of 0.63. Statistical scrutiny through paired sample t-tests corroborates significant disparities between pre-test and post-test scores, evidenced by a tcount (16.28) exceeding the critical ttable value …

Error Analysis Of Learners’ Problem-Solving Abilities In Mathematics Courses: A Newman Error Analysis (Nea) Approach, Aprilita Ekasari, Don Jaya Putra

Jurnal Pendidikan Sains

This study endeavors to systematically discern the spectrum of learner errors manifesting in problem-solving processes within the domain of mathematics, specifically focusing on the intricacies of integration, utilizing Newman Error Analysis (NEA) as the guiding framework. The cohort under investigation comprises 14 first-year students hailing from the Department of Physics Education at Musamus University, Merauke. Employing a descriptive methodology underscored by a qualitative orientation, this research incorporates tests and interviews as primary instruments for data collection. The tests are designed to meticulously evaluate the array of errors committed by learners, as per the tenets of Newman’s model. Additionally, a subset …

Synthesis, Molecular Characteristics, And Antibacterial Assessment Of Marine Hydroid Aqueous Extract-Based Silver Bio-Nanoparticles, Fredryk Mandey, Aulia Rhamdani Arfan, Rugaiyah Andi Arfah

Makara Journal of Science

This investigation aims to synthesize, analyze the molecularity, and test the ability of bacterial inhibition capability of silver nanoparticles that have been synthesized by simply mixing silver nitrate and aqueous extracts of marine natural products with and without the addition of amylum as a stabilizing agent. This research, with and without the addition of amylum as a stabilizing agent, obtained 39.0 and 55.2 mg of solids of round-shaped morphology silver nanoparticles with diameters of 87.9 and 103.0 nm., respectively. In addition, the antibacterial testing assay against Staphylococcus aureus and Escherichia coli showed some considerably good results. S. aureus with the …

Recent Advances In Solar Photo(Electro)Catalytic Nitrogen Fixation, Jun-Bo Ma, Sheng Lin, Zhiqun Lin, Lan Sun, Chang-Jian Lin

Journal of Electrochemistry

Ammonia (NH₃) is an essential chemical in modern society. It is currently produced in industry by the Haber-Bosch process using H₂ and N₂ as reactants in the presence of iron-based catalysts at high-temperature (400–600 ^oC) and extremely highpressure (20–40 MPa) conditions. However, its efficiency is limited to 10% to 15%. At the same time, a large amount of energy is consumed, and CO₂ emission is inevitably. The development of a sustainable, clean, and environmentally friendly energy system represents a key strategy to address energy crisis and environmental pollution, ultimately aiming to achieve carbon neutrality. …

Advancements In Characterization Of Ancient Potteries From Southeast Asia: A Review Of Analytical Techniques, Chitnarong Sirisathitkul

Makara Journal of Science

Ancient potteries offer valuable information regarding technological advancements, life dynamics, cultural diversity, and trade routes in the past. Earthenware, stoneware, and porcelain from Southeast Asia have been characterized using several analytical techniques, as reviewed in this article. Fluorescent and diffracted X-rays give rise to elemental and phase compositions, respectively. Examination of molecular bonds requires vibrational spectroscopy, which is useful for the identification of organic materials in ancient potteries. With the advent of portable X-ray fluorescence and Raman spectrometry, on-site analysis of archeological ceramics is now possible. For in-depth analysis, synchrotron light sources can provide new insights into artifacts through X-ray …

The Determination Of Pzc And Differential Capacitance Curve Of Platinum-Alkaline Polymer Electrolyte Interfaces, Chen-Xi Liu, Ze-Ping Zou, Mei-Xue Hu, Yu Ding, Yu Gu, Shuai Liu, Wen-Jing Nan, Yi-Chang Ma, Zhao-Bin Chen, Dong-Ping Zhan, Qiu-Gen Zhang, Lin Zhuang, Jia-Wei Yan, Bing-Wei Mao

Journal of Electrochemistry

Alkaline polymer electrolyte (APE) is the core component of modern alkaline hydrogen and oxygen fuel cells, and its single ion conductor nature makes the "electrode/APE" interfaces different from the conventional "electrode/solution" interfaces in terms of ion distribution, electrical double layer structure and polarization behavior. Due to the complexity of the APE and the associated solid-solid interfaces, fundamental investigations are challenging and deeper understanding of the structures and properties of such interfaces is in the infant stage. In this work, we aim to investigate the double layer structure from the aspects of differential capacitance curve and potential of zero charge (PZC) …

Micropatterning And Functionalization Of Single Layer Graphene: Tuning Its Electron Transport Properties, Miao-Miao Cui, Lian-Huan Han, Lan-Ping Zeng, Jia-Yao Guo, Wei-Ying Song, Chuan Liu, Yuan-Fei Wu, Shi-Yi Luo, Yun-Hua Liu, Dong-Ping Zhan

Journal of Electrochemistry

As a promising 2D material, graphene exhibits excellent physical properties including single-atom-scale thickness and remarkably high charge carrier mobility. However, its semi-metallic nature with a zero bandgap poses challenges for its application in high-performance field-effect transistors (FETs). In order to overcome these limitations, various approaches have been explored to modulate graphene's bandgap, including nanoscale confinement, external field induction, doping, and chemical micropatterning. Nevertheless, the stability and controllability still need to be improved. In this study, we propose a feasible method that combines electrochemical bromination and photolithography to precisely tune the electron transport properties of single layer graphene (SLG). Through this …

Introductory Chemistry Student Success: Evaluating Peer-Led Team Learning And Describing Sense Of Belonging, Jessica D. Young

USF Tampa Graduate Theses and Dissertations

Identifying approaches that make science and engineering education broader and more inclusive is core to discipline based education research. Both fundamental and applied research are important in advancing a STEM education that retains the necessary scientists of the U.S.’s future. Thus, the major goal of this work was to evaluate and describe efforts that promote student success within introductory STEM courses. This began with applied research by utilizing quantitative analyses like case-matching, logistic regression, independent sample t-tests, and repeated measures while evaluating the efficacy of peer-led team learning (PLTL). Later, this work delves into qualitative approaches to answer fundamental research …