Effects Of Varying Ph, Temperature, And Sucrose Concentration On The Activity Of Invertase Enzyme,
2026
University of Arkansas, Fayetteville
Effects Of Varying Ph, Temperature, And Sucrose Concentration On The Activity Of Invertase Enzyme, B. Rainwater, S. Pratihar
Journal of the Arkansas Academy of Science
The purpose of this research is to study the factors that affect the enzymatic activity of invertase, extracted from baker’s yeast, on hydrolysis of sucrose in aqueous medium. Invertase, a glycoprotein, is an enzyme in the glycoside hydrolase family. It catalyzes the hydrolysis of sucrose producing equimolar mixture of a-D-glucose and b-D-fructose. Invertase shows high affinity for the substrate, and is capable of both cleaving the glycosidic linkage in sucrose and transferring ab-D-O-fructofuranoside residue to an acceptor substrate. (Toledo et al. 2019). A detailed mechanism of the action of invertase was postulated by Shall et al. (Shall et al. 1971). …
Long-Range Fit: A Software Package For The Representation And Study Of Long-Range Molecular Interactions,
2026
Missouri University of Science and Technology
Long-Range Fit: A Software Package For The Representation And Study Of Long-Range Molecular Interactions, Adrian L. Batista-Planas, Ernesto Quintas-Sánchez, Richard Dawes
Chemistry Faculty Research & Creative Works
Describing intermolecular forces is fundamental to modeling and predicting the behavior of molecular systems. In particular, long-range molecular interactions with electrostatic, induction, and dispersion as the main components play a critical role, especially for low-temperature and low-density regimes. Long-range interactions are often described through perturbation theory, representing the electronic charge distribution via a multipolar series of the moments and polarizability tensors corresponding to each molecule. However, while the theory is well established, obtaining the resulting analytical expressions (and their practical implementation) constitutes a highly complex and system-dependent task. To address this challenge, we developed long-range-fit (LRF), an interactive and user-friendly …
Design Of Lithium-Based Battery Electrolyte Compositions For Extreme Operating Conditions Using Alternative Solvents, Co-Solvents And Additives,
2026
CUNY Graduate Center
Design Of Lithium-Based Battery Electrolyte Compositions For Extreme Operating Conditions Using Alternative Solvents, Co-Solvents And Additives, Michael J. Keating
Dissertations, Theses, and Capstone Projects
Lithium-ion battery utilization is widespread due to relatively high capacity and long cycle life. Advanced technologies have specific demands of their energy storage devices that traditional Li-ion batteries are unable to meet. Lithium-ion batteries utilize a graphite anode which has a limited theoretical capacity. Traditional lithium-ion batteries also utilize flammable solvents in their electrolyte mixtures. Due to the flammable electrolyte, lithium-ion batteries are not considered practical for large scale applications. Additionally, the lithium-ion battery has a narrow optimal operating temperature window. The temperature limitation of lithium-ion batteries leads to issues for many applications such as operating in extreme temperature environments, …
A Computational Study Of The Chemomechanics Of Paracetamol Polymorphs: Towards Improving Drug Tabletability,
2026
The American University in Cairo AUC
A Computational Study Of The Chemomechanics Of Paracetamol Polymorphs: Towards Improving Drug Tabletability, Karim Nader Samra
Theses and Dissertations
The mechanical properties of pharmaceutical crystals are of great importance in tablet manufacturing. Also, knowing the mechanical properties of different polymorphs of the same crystal can reduce the overall production cost. In this study, computational work was done via performing density functional theory calculations on 3 paracetamol crystal polymorphs Form I, II, and III. Understanding the chemical bonding helps in predicting the key elastic properties for different crystallographic directions. In Form II, lattice vector C is dominated with the intermolecular hydrogen bond OH…O giving it the stiffest Young Modulus and the least Poisson’s ratio. Then comes the A-Axis which contains …
Development Status And Existing Problems Of Ion-Solvation Membranes For Electrolysis Of Water,
2026
State Key Laboratory of Advanced Fiber Materials, College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China
Development Status And Existing Problems Of Ion-Solvation Membranes For Electrolysis Of Water, Zheng-Yuan Zhou, Yu-Tao Sun, Zheng-Bang Liu, Chuan-Zheng Wang, Yong-Nan Zhou, Xi Luo, Tian-Chi Zhou, Jin-Li Qiao
Journal of Electrochemistry
Ion-solvaing membranes (ISMs) have received extensive attention in recent years as a key component in electrochemical energy conversion and storage devices. This article provides an overview of structural composition, performance advantages, research progress, ion conduction mechanism and existing issues of ISMs, primarily classifying them according to the matrix structure. A detailed analysis of performance enhancement methods, key performance indicators of ISMs and performance influencing factors is also presented. The article contributes to further optimizing the design and application of ion-solvation membranes, providing theoretical support for the development of fields such as hydrogen production through electrolysis of water and electrochemical energy …
Iron-Involved Orr Electrocatalysts Under The Lens Of In-Situ/Operando Mössbauer Spectroscopy,
2026
CAS Key Laboratory of Science and Technology on Applied Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning, China 116023; Mössbauer Effect Data Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning, China 116023
Iron-Involved Orr Electrocatalysts Under The Lens Of In-Situ/Operando Mössbauer Spectroscopy, Sumbal Farid, Jun-Hu Wang
Journal of Electrochemistry
Exploring cost-effective and efficient catalysts for oxygen reduction reaction (ORR) poses a significant challenge, especially in the pursuit of alternatives to precious metals like platinum. Significant advancements have driven electrochemists to develop efficient ORR catalysts using abundant materials, particularly iron (Fe)-based, known for their exceptional performance in ORR. While the crucial function of Fe in boosting ORR catalytic activity is recognized, the connection between material attributes and catalytic performance remains enigmatic. Understanding the dynamic processes involved in oxygen electrocatalysis is paramount for designing precious-metals-free ORR electrocatalysts. Mössbauer spectroscopy stands out as a powerful technique for deciphering the structural characteristics of …
The Ntp Anode For Aqueous Sodium Ion Batteries: Recent Advances And Future Perspectives,
2026
School of Materials Science and Engineering, Xiamen University of Technology, Xiamen, 361024, Fujian, China; School of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, P R China
The Ntp Anode For Aqueous Sodium Ion Batteries: Recent Advances And Future Perspectives, Ming-Li Wang, Xue-Ying Su, Zheng-Xiang Shan, Shu-Zhe Yang, Heng-Rui Guo, Hao Luo, Dong-Liang Chao
Journal of Electrochemistry
Aqueous sodium-ion batteries (ASIBs) have attracted great attention in aqueous batteries due to their merit of high safety. However, the constrained work potential and insufficient chemical stability of anode materials in aqueous electrolytes hinder the large-scale application of ASIBs. Sodium titanium phosphate, NaTi2(PO4)3 (NTP), is considered one of the most promising anode materials for ASIBs due to its excellent electrochemical performance and tunable structure. Recently, great achievements have been made in the development of NTP, however, a comprehensive review of existing studies is still lacking. This article firstly introduces the basic properties of NTP and …
Carbon Supported Octahedral Ptni Nanoparticles (Oct-Ptni/C) As A Cathode Catalyst For Proton Exchange Membrane Fuel Cells (Pemfcs) With Improved Activity And Durability,
2026
Yunnan Key Laboratory of Modern Separation Analysis and Substance Transformation, College of Chemistry and Chemical Engineering, Yunnan Normal University, Kunming, Yunnan, 650500, P.R. China
Carbon Supported Octahedral Ptni Nanoparticles (Oct-Ptni/C) As A Cathode Catalyst For Proton Exchange Membrane Fuel Cells (Pemfcs) With Improved Activity And Durability, Zi-Wei Feng, Hai-Zhong Chen, Xiao Duan, Ling Tang, Yun-Kun Zhao, Long Huang
Journal of Electrochemistry
Proton exchange membrane fuel cells (PEMFCs) are considered as a promising renewable power source. However, the massive commercial application of PEMFCs has been greatly hindered by their high expense and less-satisfied performance mainly due to the sluggish oxygen reduction reaction (ORR) kinetics even on state-of-the-art Pt catalyst. Octahedral PtNi nanoparticles (oct-PtNi NPs) with excellent ORR activity in a half-cell have been widely studied, while their performance in membrane electrode assembly (MEA) has much less reported. Herein, we investigated the MEA performance using the carbon supported oct-PtNi NPs (oct-PtNi/C) as the cathode catalyst. Under the mild acid washing condition, the surface …
Applications For The Quasi-Atomic Orbital And Constrained Density Functional Theory Methods On Catalytic Reactions,
2026
Louisiana State University and Agricultural and Mechanical College
Applications For The Quasi-Atomic Orbital And Constrained Density Functional Theory Methods On Catalytic Reactions, Alvaro David Loaiza Orduz
LSU Doctoral Dissertations
Selective activation of C–O, C–H, and C–C bonds underpins biomass upgrading, alkane functionalization, and CO₂ conversion. Despite their importance, the electronic factors governing catalytic performance remain incompletely understood, and many industrial processes still rely on empirical trends or material-specific observations. This dissertation addresses this gap by applying density functional theory (DFT), thermodynamic decomposition, and electronic-structure analysis to identify unifying principles of reactivity across transition-metal phosphides, vanadate oxides, copper-based electrocatalysts, and mixed IrO₂–RuO₂ layers. This work examines how charge transfer, orbital localization, and ligand-induced perturbations control reaction pathways in diverse catalytic systems. C–O bond scission in 2-methyltetrahydrofuran (MTHF) and methanol was …
Parameter-Free Determination Of Au Nanorod Dimensions Using Depolarized Dls And Genetic Optimization,
2026
Case Western Reserve University
Parameter-Free Determination Of Au Nanorod Dimensions Using Depolarized Dls And Genetic Optimization, Nehal Nupnar, Geofrey Nyabere, Claire M.B. Bolding, Kiril A. Streletzky, Michael J.A. Hore
Physics Faculty Publications
Gold nanorods (AuNRs) have received considerable attention for their distinctive optical properties and well-defined, low-polydispersity dimensions. These characteristics position them as promising candidates for diverse applications in imaging, sensing, and treating diseases. However, accurate characterization of AuNRs in their native solution state, which is crucial to many applications, presents many challenges─especially if AuNRs are coated with surface layers (e.g., surfactants or grafted polymers). When applied to AuNRs with functionalized surfaces, common techniques such as transmission electron microscopy (TEM), small-angle scattering, and dynamic light scattering (DLS) can present limitations such as small sample sizes, the inability to detect light elements, a …
Efficient Organic Molecular Crystal Structure Prediction Using The Density Functional Tight-Binding Method,
2026
Binghamton University--SUNY
Efficient Organic Molecular Crystal Structure Prediction Using The Density Functional Tight-Binding Method, Maureen M. Kitheka, Yan Jing, Yan Yao, Puja Goyal
Faculty Publications – Chemistry
Over the years, computational crystal structure prediction (CSP) for organic molecules has thrived as an area of research, spanning various scientific disciplines and having significant applications in industries such as pharmaceuticals and agrochemicals. Within the field of batteries, redox-active organic materials (ROMs) such as quinones have received increased attention as promising electrode materials for rechargeable batteries. However, experimental determination of the crystal structure of intermediate species formed during the discharge/charge cycle can often be challenging. Incomplete X-ray diffraction patterns can also lead to difficulties in crystal structure determination for ROMs used in batteries. Use of a semiempirical electronic structure method …
Theoretical Study Of Long-Range Molecular Interactions,
2026
Missouri University of Science and Technology
Theoretical Study Of Long-Range Molecular Interactions, Adrian Luis Batista-Planas
Doctoral Dissertations
Describing intermolecular forces is fundamental to modeling and predicting the behavior of molecular systems. In particular, long-range molecular interactions—with electrostatic, induction, and dispersion as main components—play a critical role, especially for low-temperature and low-density regimes. Long-range interactions are often described through perturbation theory, representing the electronic charge distribution via multipolar series of the moments and polarizability tensors corresponding to each molecule. However, while the theory is well-established, obtaining the resulting analytical expressions (and their practical implementation) constitutes a highly complex and system-dependent task. To address this challenge, we developed Long-Range-Fit (LRF), an interactive and user-friendly software package designed to automate …
Synthesis And Characterization Of Polymethylhydrosiloxane-Based Materials: Environmental Remediation, Unusual Oxidative Behavior, And Kinetic Analysis,
2026
University of Texas at Arlington
Synthesis And Characterization Of Polymethylhydrosiloxane-Based Materials: Environmental Remediation, Unusual Oxidative Behavior, And Kinetic Analysis, Hannah M. Hayes
Chemistry & Biochemistry Dissertations
Porous materials have a wide range of applications. One of which is environmental remediation as a sorbent. Synthetic materials are beneficial as they have more selectivity compared to natural sorbents however, they are more costly. Recently, a publication produced an ambiently dried gel using a copolymer of polymethylhydrosiloxane (PMHS) and polydimethylsiloxane (PDMS) after modification with vinylmethyldimethoxysilane (VMDMS). PMHS is a byproduct of the silicone industry which makes the synthesis cheaper and more environmentally friendly. The precursor ratio must be tailored to account for the change in polymer used. In this study, various ratios of PMHS and VMDMS as well as …
Connections Between Mathematics And Chemistry: An Interdisciplinary Undergraduate Curricular Initiative,
2026
Saint Michael's College
Connections Between Mathematics And Chemistry: An Interdisciplinary Undergraduate Curricular Initiative, George Ashline, Bret Findley
Journal of Mathematics and Science: Collaborative Explorations
In this article, we describe an undergraduate curricular initiative involving mathematics and chemistry faculty and students. Supported by a grant from the National Science Foundation Scholarships in Science, Technology, Engineering, and Mathematics Program, a program designed to encourage the study of and connections between quantitative fields and life sciences, this interdisciplinary collaboration features undergraduate student research and involves the development of curricular connections between mathematics and chemistry. Through this initiative, we have created activities for calculus courses featuring chemistry applications as well as activities for chemistry courses showcasing mathematical concepts. After the implementation of these curricular enhancements, we gathered student …
Elucidating The Impacts Of Non-Covalent Interactions In Organic Materials Through A Multiscale Computational Approach,
2026
University of Kentucky
Elucidating The Impacts Of Non-Covalent Interactions In Organic Materials Through A Multiscale Computational Approach, Sashen A. Ruhunage
Theses and Dissertations--Chemistry
Noncovalent interactions (NCIs) in π-conjugated organic materials serve as tunable levers that influence molecular structure and intermolecular interactions in the condensed phase and, in turn, impact the electronic, optical, and mechanical properties of these materials. NCIs include attractive dispersion, electrostatic, and induction interactions, as well as repulsive exchange interactions. However, how to design materials with NCI considerations remains an open question across many fields. Here, we seek to provide an electronic and atomistic perspective on these interactions through multiscale simulations to aid materials design, processing, and performance optimization. In this study, we investigate NCIs and their effects across various systems …
Real-Space Imaging Of The Electron-Pair Density Hole In Molecular Auger-Meitner Decay,
2026
University of Oxford
Real-Space Imaging Of The Electron-Pair Density Hole In Molecular Auger-Meitner Decay, Mats Simmermacher, Nathan Goff, Andres Moreno Carrascosa, Elke Fasshauer, Thomas Northey, Lingyu Ma, Haiwang Yong, Brian Stankus, Asami Odate, Xuan Xu, Wenpeng Du, Kyle Acheson, Joseph C. Cooper, Daniel Ratner, Mengning Liang, Ruaridh Forbes, Michael P. Minitti, Adam Kirrander, Peter M. Weber
Physics Faculty Publications
Electrons in matter can rearrange extremely quickly under external perturbations, underpinning subsequent structural and chemical transformations. Coulomb interactions between neighbouring electrons often shape this response, giving rise to correlated motion and strongly affecting the distribution of electrons in the system. Here we show that non-resonant hard X-ray scattering can directly access changes in the radial electron-pair density during the rapid rearrangement of core and valence electrons. We do this by studying sulfur hexafluoride molecules undergoing Auger–Meitner decay. We exploit a second-order interaction between the X-ray photons and the molecules to trigger and probe the decay dynamics with a single pulse, …
Deciphering Ultrafast Photoinduced And Photocatalytic Reaction Dynamics On Oxide Surfaces: Direct Detection Of Radical Intermediates, Fragment Trapping, And Carbon–Carbon, Carbon–Oxygen, And Carbon–Hydrogen Bond Formation Pathways,
2026
University of Central Florida
Deciphering Ultrafast Photoinduced And Photocatalytic Reaction Dynamics On Oxide Surfaces: Direct Detection Of Radical Intermediates, Fragment Trapping, And Carbon–Carbon, Carbon–Oxygen, And Carbon–Hydrogen Bond Formation Pathways, Aakash Gupta
Graduate Studies Theses and Dissertations 2026
Understanding photoinduced reactions at solid interfaces is essential for advancing heterogeneous photocatalysis, surface photochemistry, and energy conversion technologies. This dissertation investigates the ultrafast dynamics of reactive intermediates, fragment trapping, and radical-mediated bond formation on oxide surfaces using time-of-flight mass spectrometry in conjunction with femtosecond pump-probe spectroscopy. Various experimental findings are validated through collaborations via density functional theory (DFT). By combining temporal, mass, and energy-resolved measurements, this work provides molecular-level insight into the elementary processes governing light-driven surface reactions. The photodissociation dynamics of CH3I adsorbed on TiO2(110), TiO2(100), and amorphous silicon oxide surfaces are examined …
A Theoretical Study Of Molecular Photoionization: Applications To Molecules Of Astrophysical And Atmospheric Interest,
2026
University of Central Florida
A Theoretical Study Of Molecular Photoionization: Applications To Molecules Of Astrophysical And Atmospheric Interest, Conner Penson
Graduate Studies Theses and Dissertations 2026
This thesis is devoted to the development of the model for total molecular photoionization spectra which is general to diatomic molecules and the application of this model to two benchmark systems, CH and N2, for verification. This model combines multi-channel quantum defect theory, first-principles ab initio molecular calculations, and vibrational frame transformation to accurately model molecular photoionization and electron impact including vibrational dynamics. The scattering data and transition dipole moments for the molecular systems were calculated using R-matrix method through the UKRMol+ codes. A vibrational frame transformation is then performed and multi-channel quantum defect theory is used to calculate closed …
Novel Chiral Interstellar Molecules: Quantum Anharmonic Ir And Vcd Predictions,
2026
Michigan Technological University
Novel Chiral Interstellar Molecules: Quantum Anharmonic Ir And Vcd Predictions, Meredith Paik
Dissertations, Master's Theses and Master's Reports
The 2016 discovery of the chiral molecule propylene oxide (C3H6O) in the interstellar medium (ISM) has opened new avenues into explaining the origin of biomolecular homochirality on Earth. Thus, studies of chiral molecules in the ISM may be able to reveal more about the mechanism behind homochirality. However, while the search for chiral molecules in space has become an active field of study, astrochemical researchers have yet to detect other chiral molecules in the ISM. For this purpose, numerous characteristics for detectability have been outlined that may facilitate the discovery of other interstellar chiral molecules. With …
31p Solution Nmr Investigation Of Abasic Dna,
2026
Missouri State University
31p Solution Nmr Investigation Of Abasic Dna, Clarissa R. Krimmel
Graduate Theses/Dissertations
Base excision repair (BER) mechanisms fix single base lesions in DNA, such as T:G mismatches. During the base excision repair mechanism, an abasic site (AP site) is formed as an intermediate. AP sites are unstable and highly mutagenic; they can stop DNA replication. This research investigates how the conformational properties of abasic sites in DNA affect the binding recognition of enzymes involved in DNA repair mechanisms, including BER. Three different abasic sequences are being analyzed for this research project. A second project looks at the effects of a naturally occurring purine derivative, hypoxanthine, on the DNA backbone. These hypoxanthine lesions …
