Carbon Dioxide Reduction On Large Area Liquid Metal Gallium-Indium Electrocatalysts,
2023
University of Arkansas, Fayetteville
Carbon Dioxide Reduction On Large Area Liquid Metal Gallium-Indium Electrocatalysts, Thomas Hollis
Chemistry & Biochemistry Undergraduate Honors Theses
Carbon dioxide (CO2) is widely known as a greenhouse gas that contributes to global warming due to the burning of fossil fuels. The carbon dioxide reduction reaction (CO2RR) is widely studied to reutilize CO2 to useful products, including methane, ethane, and carbon monoxide. This project studies the use of liquid metal gallium-indium as an electrocatalyst to perform CO2 reduction to carbon monoxide (CO) or possibly solid carbon in various solutions. Gallium-indium is characterized and studied through its “wetting” properties and adhesion to substrate foil through the measurement of contact angles inside solution. These liquid …
Mechanisms Of Formation Of Novel Guanine-Guanine Cross-Links As Major End Products During One-Electron Oxidation Of Guanine Derivatives,
2023
East Tennessee State University
Mechanisms Of Formation Of Novel Guanine-Guanine Cross-Links As Major End Products During One-Electron Oxidation Of Guanine Derivatives, Evan Dunn
Undergraduate Honors Theses
Guanine (G), as the most oxidizable base in DNA, is the major focus of studies of oxidation damage to DNA. The present thesis reports the first detailed characterization of G dimerization products potentially resulting from recombination of neutral G• radicals. Previous research has discovered a novel type of products of G• dimerization, D1 and D2, formed from one-electron oxidation of G derivatives. However, the mechanism of this dimerization remains elusive. While there appears to be a tautomeric equilibrium between two forms of G•, G(N1-H)• or G(N2-H)•, it remains unclear which intermediate participates in the formation of …
Collisional Excitation Of C2h- By H2: New Interaction Potential And Scattering Calculations,
2023
Missouri University of Science and Technology
Collisional Excitation Of C2h- By H2: New Interaction Potential And Scattering Calculations, Fabien Dumouchel, Ernesto Quintas-Sánchez, Christian Balança, Richard Dawes, François Lique, Nicole Feautrier
Chemistry Faculty Research & Creative Works
Interstellar Anions Play an Important Role in Astrochemistry as Being Tracers of the Physical and Chemical Conditions in Cold Molecular Clouds and Circumstellar Gas. the Local Thermodynamic Equilibrium is Generally Not Fulfilled in Media Where Anions Are Detected and Radiative and Collisional Data Are Required to Model the Observed Lines. the C2H- Anion Has Not Yet Been Detected in the Interstellar Medium; However, Collisional Data Could Be Used for Non-LTE Models that Would Help in Identifying the Most Intense Lines. for This Purpose, We Have Computed the First 4D Potential Energy Surface (PES) of the C2H--H2 Complex using an Explicitly …
Probing The Effect Of Nitrogen And Boron Doping On Structures, Properties, And Stability Of C20 Clusters,
2023
Kennesaw State University
Probing The Effect Of Nitrogen And Boron Doping On Structures, Properties, And Stability Of C20 Clusters, Ramsay Revennaugh, Martina Kaledin
Symposium of Student Scholars
Fullerenes are carbon molecules arranged in a closed hollow shell to form spherical-like structures. These clusters exist in various sizes, Cn, with the smallest being C20. C20, often when doped with other elements, has shown promise in creating new materials as a catalyst and as energy storage material. Here, we look at the existence of C20 doped with nitrogen or boron atoms using density functional theory (DFT). C20 is doped with one to three boron or nitrogen atoms, respectively, including the five different C18N2 / C18B2 …
Ab Initio Calculations Of Vibrational Spectra Of Model Peptides,
2023
Kennesaw State University
Ab Initio Calculations Of Vibrational Spectra Of Model Peptides, Katheryn Foust, Martina Kaledin
Symposium of Student Scholars
The function of biological molecules is closely related to their spatial structure and conformational dynamics. Therefore, understanding the structure and functions of small peptides contributes to gaining insight into the behavior of more complex systems. The peptide bond (-CO-NH-) is among the very important binding patterns in biochemistry. It links amino acids together, specifies rigidity to the protein backbone, and includes the two essential docking sites for hydrogen-bond-mediated protein folding and protein aggregation, namely, the C=O acceptor and the N-H donor parts. Therefore, the C=O (amide-I) and N-H (amide-A) vibrations provide sensitive and widely used probes into the structure of …
A Comparative Study Of Specific Enthalpy Of Aromatic Hydrocarbons With Simple Carbohydrates,
2023
Arkansas Tech University
A Comparative Study Of Specific Enthalpy Of Aromatic Hydrocarbons With Simple Carbohydrates, Kohl D. Kervin, Subha Pratihar
ATU Research Symposium
Calorimetry is an aspect of chemistry primarily focused on determining the enthalpy of reactions (∆Hrxn). In the bomb calorimetry technique, the heat of combustion of chemical compounds can be measured experimentally. From this data and the application of Hess’s Law, ∆the Hrxn of several chemical reactions can be determined. The technique of bomb calorimetry can be applied to food, fuels, pharmaceuticals, and many other fields. The objective of the present project is to determine the specific enthalpy of various simple carbohydrates (naturally occurring sugars) through bomb calorimetry and compare it with that of aromatic hydrocarbons.
By performing benzoic acid standardization …
Additivity Of Diene Substituent Gibbs Free Energy Contributions For Diels–Alder Reactions Between Me2c=Cme2 And Substituted Cyclopentadienes,
2023
Northern Illinois University
Additivity Of Diene Substituent Gibbs Free Energy Contributions For Diels–Alder Reactions Between Me2c=Cme2 And Substituted Cyclopentadienes, Thomas M. Gilbert, Austin S. Flemming, Brendan C. Dutmer
Faculty Peer-Reviewed Publications
Systematic computational studies of pericyclic Diels–Alder reactions between (H3C)2C═C(CH3)2, 1, and all permutations of substituted cyclopentadienes c-C5R1R2R3R4R5aR5b (R = H, CH3, CF3, F) allowed isolation of substitutional effects on Gibbs free energy barrier heights and reaction Gibbs free energies. “Average Substitution Gibbs Free Energy Correction” ΔGASC#‡/ΔGASC# values for each substituent in each position appeared to be additive. Substituent effects on barriers showed interesting contrasts. Methyl substitution at positions 5a and 5b increased barriers significantly, while substitution at all other positions had essentially no impact. In contrast, fluoro substitution at positions 5a and 5b lowered barriers more than substitution at other …
Scanning Probe And Spectroscopic Investigations Of Polarization-Driven Electronic Interactions At The Inorganic/Organic Interface Of 2d Materials,
2023
University of Massachusetts Amherst
Scanning Probe And Spectroscopic Investigations Of Polarization-Driven Electronic Interactions At The Inorganic/Organic Interface Of 2d Materials
Doctoral Dissertations
My thesis focuses on understanding the changes in electronic properties of two-dimensional materials produced by surface interactions not limited to charge exchange. Recent work from our group demonstrated that both small molecules and polymers can function as effective charge dopants for monolayered 2D materials such as MoS2 and graphene, changing the Fermi energy by either donating or accepting electron density to/from the 2D material. Additionally, the underlying support material was found to play a significant role, where higher dielectric constant supports result in larger magnitude of Fermi energy shift of the 2D material because less of the dopant interaction …
Diffractive Imaging Of Laser Induced Molecular Reactions With Kiloelectron-Volt Ultrafast Electron Diffraction,
2023
University of Nebraska–Lincoln
Diffractive Imaging Of Laser Induced Molecular Reactions With Kiloelectron-Volt Ultrafast Electron Diffraction, Yanwei Xiong
Theses, Dissertations, and Student Research: Department of Physics and Astronomy
Capturing the structural changes during a molecular reaction with ultrafast electron diffraction (UED) requires a high spatiotemporal resolution and sufficiently high signal-to-noise to record the signals with high fidelity. In this dissertation, I have focused on the development of a tabletop gas phase keV-UED setup with a femtosecond temporal resolution. A DC electron gun was employed to generate electron pulses with a high repetition rate of 5 kHz. The space charge effect in the electron pulse was ameliorated by compressing the 90 keV electron pulse longitudinally with a time varying electric field in an RF cavity. The velocity mismatch between …
Modeling Excited State Processes In Molecular Aggregates By Constructing An Adaptive Basis For The Hierarchy Of Pure States,
2023
Southern Methodist University
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 …
Synthesis And Characterization Of New Azo Dyes Derived From Acyclovir And Sulfamethoxazole And Study Their Biological Activity,
2023
Hadhrahout University
Synthesis And Characterization Of New Azo Dyes Derived From Acyclovir And Sulfamethoxazole And Study Their Biological Activity, Abdul Rahman Y. Wahoud, Thanaa Shriteh, Ali Yousef, Mohammad Mazen Kondakji
Hadhramout University Journal of Natural & Applied Sciences
In this research, two new azo dyes, 9-(2-Hydroxy-ethoxymethyl)-2-(2-hydroxy5nitrophenylazo)-1,9-dihydro-purin-6-one and 4-(2-Hydroxy-napHthalen-1-ylazo)-N-(5-methyl-isoxazol-3-yl)-benzenesulfonamide, derived from Acyclovir and Sulfamethoxazole was synthesized. The first dye synthesis was started by diazation of acyclovir, then combined with 4-nitrophenol activated with potassium hydroxide 10%, yielding 80%, and its purity was verified by thin layer chromatography (TLC). The second dye synthesis was started by diazation of Sulfamethoxazole then combined with β-naphthol activated with potassium hydroxide 10%, yielding 87%, and its purity was verified by thin layer chromatography (TLC). The identity of the resulting pigments was determined based on spectroscopic methods such as infrared spectroscopy, proton nuclear magnetic resonance spectrum …
Minimal Auxiliary Basis Set Approach For The Electronic Excitation Spectra Of Organic Molecules,
2023
Case Western Reserve University
Minimal Auxiliary Basis Set Approach For The Electronic Excitation Spectra Of Organic Molecules, Zehao Zhou, Shane M. Parker
Faculty Scholarship
We report a minimal auxiliary basis model for time-dependent density functional theory (TDDFT) with hybrid density functionals that can accurately reproduce excitation energies and absorption spectra from TDDFT while reducing cost by about \change{two} orders of magnitude. Our method, dubbed TDDFT-ris, employs the resolution-of-the-identity technique with just one $s$-type auxiliary basis function per atom for the linear response operator, where the Gaussian exponents are parametrized across the periodic table using %using tabulated atomic radii with a single global scaling factor. By tuning on a small test set, we determine a single functional-independent scale factor that balances errors in excitation energies …
Author Spotlight,
2023
Chinese Chemical Society | Xiamen University
Recent Advances In Exploring Highly Active & Durable Pgm-Free Oxygen Reduction Catalysts,
2023
College of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, PR China
Recent Advances In Exploring Highly Active & Durable Pgm-Free Oxygen Reduction Catalysts, Yuan Li, Miao-Ying Chen, Bang-An Lu, Jia-Nan Zhang
Journal of Electrochemistry
In order to reduce the considerable usage of expensive but scarce platinum at the cathode in proton exchange membrane fuel cells (PEMFCs), it is necessary to pursue alternatives to platinum. The most promising platinum group metal (PGM)-free catalysts for oxygen reduction reaction (ORR) are atomically dispersed, and nitrogen-coordinated metal site catalysts denoted as M-N-C (M = Fe, Co, or Mn, etc.). Over the last few decades, there have been great advances in these catalysts with high ORR activity and promising initial fuel cell performance approaching traditional Pt/C catalysts. However, the stability of these highly active Fe-N-C catalysts under practical fuel …
Research Progress In Cucurbit[N]Uril-Based Metal Nanomaterials For Electrocatalytic Applications,
2023
a Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, China; b State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China
Research Progress In Cucurbit[N]Uril-Based Metal Nanomaterials For Electrocatalytic Applications, Zong-Nan Wei, Min-Na Cao, Rong Cao
Journal of Electrochemistry
Metal nanomaterials have exhibited excellent performance in electrocatalytic applications, but they still face the problems of poor stability and limited regulation strategies. It is an efficient strategy for greatly enhanced catalytic activity and stability by introducing a second component. In this review, we provide the sketch for the combination of metal nanomaterials and cucurbit[n]urils (CB[n]s) in electrocatalytic applications. CB[n]s are a series of macrocycles with rigid structure, high stability, and function groups for coordinating with metal sites, which make them promising to stabilize and modulate the metal nanomaterials for ideal performance. The discussion classifies the roles of CB[n]s, involving CB[n]s …
Submission Guidelines,
2023
Chinese Chemical Society | Xiamen University
Supperlattice-Like Structure: Ordered Mass Transfer Endowing High Quality Output Of Fuel Cell,
2023
a Chongqing Key Laboratory of Chemical Process for Clean Energy and Resource Utilization, School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, China
Supperlattice-Like Structure: Ordered Mass Transfer Endowing High Quality Output Of Fuel Cell, Jian Wang, Wen-Hui Xuan, Qian He, Jing-Xia Jiang, Yuan-Yuan Zhou, Yao Nie, Qiang Liao, Min-Hua Shao, Wei Ding, Zi-Dong Wei
Journal of Electrochemistry
The current or voltage fluctuation in fuel cell operation is harmful to the fuel cell system and power application equipment. Here, we report a technique to eliminate such a fluctuation by the aid of new type of catalysts, superlattice-like mesoporous PtCo catalysts. The current fluctuation in fuel cells catalyzed by two invented catalysts are fixed at as low as 25 mA·cm−2 with a power of 0.75 W·cm−2 or 120 mA·cm−2 with a power of 1.01 W·cm−2, and no noticeable current decay was detected over 100 h. By contrast, a …
Preface To Special Issue: Electrocatalysis And Electrosynthesis (Ⅰ),
2023
1. College of Chemistry, Nankai University, Tianjin 30071, China
Preface To Special Issue: Electrocatalysis And Electrosynthesis (Ⅰ), Fang-Yi Cheng, Shuang-Yin Wang, Tian-Hua Zhou
Journal of Electrochemistry
No abstract provided.
Table Of Contents,
2023
Chinese Chemical Society | Xiamen University
In-Vial Detection Of Protein Denaturation Using Intrinsic Fluorescence Anisotropy,
2023
Centre for Advanced Photonics & Process Analysis, Munster Technological University Cork, T12P928, Ireland
In-Vial Detection Of Protein Denaturation Using Intrinsic Fluorescence Anisotropy, Krishnakumar Chullipalliyalil, Khaled Elkassas, Michael Mcauliffe, Sonja Vucen, Abina Crean
Cappa Publications
The conventional quality control techniques for identifying the denaturation of biopharmaceuticals includes sodium dodecyl sulfate-polyacrylamide gel electrophoresis for identifying fragmentation, ion exchange chromatography and isoelectric focusing for identifying deamidation, reverse-phase high-performance liquid chromatography (HPLC) for identifying oxidation, and size-exclusion HPLC for identifying aggregation. These stability assessments require essential processes that are destructive to the product tested. All these techniques are lab based and require sample removal from a sealed storage vial, which can breach the sterility. In this work, we investigate the heat- and surfactant-induced denaturation of an in-vial-stored model protein, bovine serum albumin (BSA), by analyzing its intrinsic fluorescence …
