Physical Sciences and Mathematics Commons^™

The Coastal Monitor: Vol. 9 No. 5, John Tanacredi Ph.D.

The Coastal Monitor

There are a multitude of lessons learned from the last 3 years of the Covid-19 pandemic. But one truly stands out ...the total lack of understanding of the basic chemistry associated with the nitrogen cycle, which in Suffolk County, NY, continues to be declared as the “evil-nitrogen”. The major source of nitrogen into the water body comes from the atmosphere which is the predominate constituent of the air we breathe79% nitrogen. Nitrogen compounds contribution to eutrophication in freshwater (ponds & lakes) systems is legendary and, the concentration of nitrogen in marine waters has always been known as a limiting agent …

Mixed Quantum/Classical Theory For Collisional Quenching Of Pahs In The Interstellar Media, Bikramaditya Mandal, Carolin Joy, Alexander Semenov, Dmitri Babikov

Chemistry Faculty Research and Publications

A computationally affordable methodology is developed to predict cross sections and rate coefficients for collisional quenching and excitation of large molecules in space, such as PAHs. Mixed quantum/classical theory of inelastic scattering (MQCT) is applied, in which quantum state-to-state transitions between the internal states of the molecule are described using a time-dependent Schrodinger equation, while the scattering of collision partners is described classically using mean-field trajectories. To boost the numerical performance even further, a decoupling scheme for the equations of motion and a Monte Carlo sampling of the initial conditions are implemented. The method is applied to compute cross sections …

Reversible Dioxygen Binding To Co(Ii) Complexes With Noninnocent Ligands, Praveen Kumar, Laxmi Devkota, Maximilian C. Casey, Anne A. Fischer, Sergey V. Lindeman, Adam T. Fiedler

Chemistry Faculty Research and Publications

A series of mononuclear Co(II) complexes with noninnocent (redox-active) ligands are prepared that exhibit metal–ligand cooperativity during the reversible binding of O₂. The complexes have the general formula, [Co^II(L^S,N)(Tp^R2)] (R = Me, Ph), where L^S,N is a bidentate o-aminothiophenolate and Tp^R2 is a hydrotris(pyrazol-1-yl)borate scorpionate with R-substituents at the 3- and 5-positions. Exposure to O₂ at room temperature results in one-electron oxidation and deprotonation of L^S,N. The oxidized derivatives possess substantial “singlet diradical” character arising from antiferromagnetic coupling between an iminothiosemiquinonate (ITSQ^•–) …

Chemical Interactions And Cytotoxicity Of Terpene And Diluent Vaping Ingredients, Yanira Baldovinos, Alexandra Archer, James C. Salamanca, Robert M. Strongin, Christie Sayes

Chemistry Faculty Publications and Presentations

Vaping devices have risen in popularity since their inception in 2007. The practice involves using a variety of commercially available devices. Internal heating systems in devices aerosolize e-liquid formulations of complex mixtures including an active ingredient (e.g., THC, CBD, and nicotine), diluents (or cutting agents), solvents, and flavoring agents (e.g., terpenes and aldehydes). The vaping toxicology literature consists of cytotoxicity studies of individual chemicals and commercial formulas. Because of the variation of e-liquid composition, there is a limited understanding of the toxicity of ingredient combinations. This study analyzed the cytotoxic effects after exposure to individual and binary mixtures of a …

Application Of Nanodisc Technology To A Membrane-Bound P450: Functional Studies And Resonance Raman Studies On Cyp51a1, Yuanqi Jing

Dissertations (1934 -)

Membrane-bound cytochrome P450s are highly insoluble and tend to form aggregations in aqueous solution due to its hydrophobic N-terminal transmembrane anchor. The traditional methodology of studying membrane-bound proteins depends on the use of detergent; however, detergent solubilization of membrane P450s does not satisfy many criteria of biochemical and biophysical studies on membrane proteins. A well-developed Nanodisc technology has been proven to be an extraordinarily efficient method of studying membrane-bound P450s. The human sterol 14-demethylases (CYP51A1) are membrane-bound P450 enzymes that catalyze oxidative removal of the C32 methyl group of lanosterol by first forming an alcohol, then an aldehyde, and finally …

Kinetics Of Isotope-Labeled Pathways In The Ozone Forming Recombination Reaction, Elizaveta Grushnikova

Dissertations (1934 -)

The ozone layer in Earth’s atmosphere is unique and plays a vital role in the development of life. Studying the mechanism behind ozone formation helps us understand the development of our planet’s atmosphere. We focus here on the anomalous mass-independent isotope effect.1 In 1981, Mauersberger et al.2 performed an experiment using weather balloons, resulting in the discovery of the anomalous isotope effect for ozone formation. Since then, other chemists have continued to investigate the theory behind this phenomenon. To understand the nature of the isotope effect, we must consider all stages of ozone formation. The basic reaction for ozone formation …

Converting Hydrazone-Based Photoswitches Into Functional Materials, Sirun Yang

Dartmouth College Ph.D Dissertations

The development of new classes of molecular switches with enhanced performance and brand-new functionalities enables practitioners to push the frontiers of adaptive materials. In the realm of photoswitches, the bistability of hydrazones (i.e., molecules that incorporate the C=N-NH functional group) allows for the kinetic trapping of polymer and supramolecular assemblies resulting in multistate actuation and emergent phenomena that are not tractable with other photoswitches. This property has transformed hydrazone photoswitches into powerful tools that can be used in understanding fundamental molecular interactions and how to apply them in modulating the physicochemical properties of materials.

Progressing from disordered to …

The Optimization Of Anion Exchange Membrane Fuel Cells And Water Electrolyzers By Varying Catalyst Design And Changing Gas Inlet Composition, Jasmine D. Bohannon

Theses and Dissertations

Researchers around the globe are looking to avoid the consequences of climate change by shifting away from the burning of fossil fuels as a source of energy. While using fossil fuels have negatively affected the earth’s climate for at least the last hundred and fifty years, the introduction of renewables looks to use abundant and naturally occurring resources. Sources of renewable energy include solar power, wind power, hydropower, geothermal energy, and biomass2 . These sources work by converting the abundant source into mechanical, electrical, or chemical energy that can be used to power industrial plants or residential areas and they …

Self-Assembling Porous Supramolecular Networks Capable Of Post-Synthetic Modification With A New Approach To Reticular Design With Semiconductor Potential, Steven A. Sloope

Theses and Dissertations

In past decades, research in self-assembling supramolecular frameworks have been produced with vast surface area, inherent from their porous nature. Predesigning monomers in a reticular manner allows a framework’s structure to be known before self-assembly occurs. This is very helpful since high porosity is sought after for many purposes such as hosting guests within the framework, post-synthetic modifications, sensing and detection, selective catalysis, semiconduction, etc. Methods of design usually focus on forming intrinsic porosity and unfortunately, sometimes the network formed is not as expected and porosity is lost.

In Chapter 1, we discuss novel ways of network formation, their potential …

Advances Of Biowaste-Derived Porous Carbon And Carbon–Manganese Dioxide Composite In Supercapacitors: A Review, A. Zekenova, M. Nazhipkyzy, Wanlu Li, A. Kalybayeva, G. Zhumanova, O. Zubova

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

One of the global problems is environmental pollution by different biowaste. To solve the problem, biowaste must be recycled. Waste-free technology is also a way of saving exhaustible raw materials. Research on electrochemical energy sources is currently the most dynamically developing area of off-grid energy. Electrochemical capacitors can operate for a long time without changing performance, they have smaller dimensions, high mechanical strength, and a wide operating temperature range. These properties are effective energy-saving devices. Therefore, supercapacitors are widely used in various industries. This review discussed the methods of obtaining and the characteristics of biowaste-derived activated carbon and carbon–manganese oxide …

Structural And Functional Studies Of Mtr4 And The Tramp Rna Surveillance Complex, Sean Johnson

Funded Research Records

No abstract provided.

Microstructural Origin Of The High-Energy Storage Performance In Epitaxial Lead-Free Ba(Zr 0.2 Ti 0.8 )O 3 Thick Films, Jun Ouyang, Xianke Wang, Changtao Shao, Hongbo Cheng, Hanfei Zhu, Yuhang Ren

Publications and Research

In our previous work, epitaxial Ba(Zr 0.2 Ti 0.8 )O 3 thick films (~1–2 μ m) showed an excellent energy storage performance with a large recyclable energy density (~58 J/cc) and a high energy efficiency (~92%), which was attributed to a nanoscale entangled heterophase polydomain structure. Here, we propose a detailed analysis of the structure–property relationship in these film materials, using an annealing process to illustrate the effect of nanodomain entanglement on the energy storage performance. It is revealed that an annealing-induced stress relaxation led to the segregation of the nanodomains (via detailed XRD analyses), and a degraded energy storage …

Comparative Study Of Bismuth Ferrite Deposition Method On Tio2 Nanotube And Performance Of Hydrogen Evolution In A Photoelectrochemical Dye-Sensitized Solar Cell Tandem System, Yunita Yunita, Muhammad Iqbal Syauqi, Jarnuzi Gunlazuardi

Makara Journal of Science

Hydrogen is a renewable and environmentally friendly energy source that can replace fossil fuels by utilizing solar energy through water splitting. The hydrogen production was conducted in this research by using a tandem system of dye-sensitized solar cell–photoelectrochemical cell (DSSC–PEC) and a TiO₂ nanotube coated with BiFeO₃ (BiFeO₃/TNT) as a photoanode in the PEC. The deposition of BiFeO₃ on TNT was prepared using the following three methods: successive ionic layer adsorption and reaction (SILAR), ultrasonication-assisted SILAR, and ultrasonic– immersion method by varying the number of deposition cycles in each method. In this study, the optimum …

Estimation Of The Bubble Point Pressure Of Multicomponent Reservoir Hydrocarbon Fluids, Benjamin Sunday Usen, Chidi Obi

Makara Journal of Science

This study developed a novel C-sharp (C#) programming language for the estimation of bubble point pressure (BPP) of various hydrocarbon mixtures at equilibrium state. The methodology was based on vapor–liquid equilibrium calculation using Peng Robinson equation of state implementation, thermodynamic equilibrium calculation and Newton-Raphson’s method for the successive substitution of the unknown variables. The equal fugacity constraint can be satisfied by obtaining the equilibrium which serves as a criterion for two or more phases to exist at equilibrium. The problem was resolved by searching for a pressure that will satisfy the two constraints. Complex calculation was performed by successively substituting …

Leveraging The Structure Of Dnaja1 To Discover Novel Potential Pancreatic Cancer Therapies, Heidi E. Roth, Aline De Lima Leite, Nicolas Y. Palermo, Robert Powers

Chemistry Department: Faculty Publications

Pancreatic cancer remains one of the deadliest forms of cancer with a 5-year survival rate of only 11%. Difficult diagnosis and limited treatment options are the major causes of the poor outcome for pancreatic cancer. The human protein DNAJA1 has been proposed as a potential therapeutic target for pancreatic cancer, but its cellular and biological functions remain unclear. Previous studies have suggested that DNAJA10s cellular activity may be dependent upon its protein binding partners. To further investigate this assertion, the first 107 amino acid structures of DNAJA1 were solved by NMR, which includes the classical J-domain and its associated linker …

Symmetry-Resolved Co Desorption And Oxidation Dynamics On O/Ru(0001) Probed At The C K-Edge By Ultrafast X-Ray Spectroscopy, Jerry Larue, Boyang Liu, Gabriel L. S. Rodrigues, Chang Liu, Jose Antonio Garrido Torres, Simon Schreck, Elias Diesen, Matthew Weston, Hirohito Ogasawara, Fivos Perakis, Martina Dell'angela, Flavio Capotondi, Devon Ball, Conner Carnahan, Gary Zeri, Luca Giannessi, Emanuele Pedersoli, Denys Naumenko, Peter Amann, Ivaylo Nikolov, Lorenzo Raimondi, Carlo Spezzani, Martin Beye, Johannes Voss, Hsin-Yi Wang, Filippo Cavalca, Jörgen Gladh, Sergey Koroidov, Frank Abild-Pedersen, Manuel Kolb, Piter S. Miedema, Roberto Costantini, Tony F. Heinz, Alan C. Luntz, Lars G. M. Pettersson, Anders Nilsson

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We report on carbon monoxide desorption and oxidation induced by 400 nm femtosecond laser excitation on the O/Ru(0001) surface probed by time-resolved x-ray absorption spectroscopy (TR-XAS) at the carbon K-edge. The experiments were performed under constant background pressures of CO (6 × 10⁻⁸ Torr) and O2 (3 × 10⁻⁸ Torr). Under these conditions, we detect two transient CO species with narrow 2π* peaks, suggesting little 2π* interaction with the surface. Based on polarization measurements, we find that these two species have opposing orientations: (1) CO favoring a more perpendicular orientation and (2) CO favoring a more parallel orientation …

Probing Mechanisms Of Binding And Allostery In The Sars-Cov-2 Spike Omicron Variant Complexes With The Host Receptor: Revealing Functional Roles Of The Binding Hotspots In Mediating Epistatic Effects And Communication With Allosteric Pockets, Gennady M. Verkhivker, Steve Agajanian, Ryan Kassab, Keerthi Krishnan

Mathematics, Physics, and Computer Science Faculty Articles and Research

In this study, we performed all-atom MD simulations of RBD–ACE2 complexes for BA.1, BA.1.1, BA.2, and BA.3 Omicron subvariants, conducted a systematic mutational scanning of the RBD–ACE2 binding interfaces and analysis of electrostatic effects. The binding free energy computations of the Omicron RBD–ACE2 complexes and comprehensive examination of the electrostatic interactions quantify the driving forces of binding and provide new insights into energetic mechanisms underlying evolutionary differences between Omicron variants. A systematic mutational scanning of the RBD residues determines the protein stability centers and binding energy hotpots in the Omicron RBD–ACE2 complexes. By employing the ensemble-based global network analysis, we …

Preface To Special Issue On Water Electrolysis For Hydrogen Production, Li Li, Jin-Song Hu, Zi-Dong Wei

Journal of Electrochemistry

No abstract provided.

Recent Development Of Low Iridium Electrocatalysts Toward Efficient Water Oxidation, Jing Ni, Zhao-Ping Shi, Xian Wang, Yi-Bo Wang, Hong-Xiang Wu, Chang-Peng Liu, Jun-Jie Ge, Wei Xing

Journal of Electrochemistry

Developing high-performance and low-cost electrocatalysts for oxygen evolution reaction (OER) is the key to implementing polymer electrolyte membrane water electrolyzer (PEMWE) for hydrogen production. To date, iridium (Ir) is the state-of-the-art OER catalyst, but still suffers from the insufficient activity and scarce earth abundance, which results in high cost both in stack and electricity. Design low-Ir catalysts with enhanced activity and stability that can match the requirements of high current and long-term operation in PEMWE is thus highly desired, which necessitate a deep understanding of acidic OER mechanisms, unique insights of material design strategies, and reliable performance evaluation norm, especially …

The Rapid Preparation Of Efficient Mofeco-Based Bifunctional Electrocatalysts Via Joule Heating For Overall Water Splitting, Ao Zhou, Wei-Jian Guo, Yue-Qing Wang, Jin-Tao Zhang

Journal of Electrochemistry

Water electrolysis is an available way to obtain green hydrogen. The development of highly efficient electrocatalysts is a current research hotspot for water splitting, but it remains challenging. Herein, we demonstrate the synthesis of a robust bifunctional multi-metal electrocatalysts toward water splitting via the rapid Joule-heating conversion of metal precursors. The composition and morphology were well regulated via altering the ratio of metal precursors. In particular, the trimetal MoC/FeO/CoO/carbon cloth (CC) electrode revealed the outstanding bifunctional electrocatalytic performance due to the unique composition and large electrochemical active surface area. Typically, the MoC/FeO/CoO/CC catalyst needed low overpotentials of 121 and 268 …

Self-Supporting Nife Ldhs@Co-Oh-Co3 Nanorod Array Electrode For Alkaline Anion Exchange Membrane Water Electrolyzer, Dan-Dan Guo, Hong-Mei Yu, Jun Chi, Zhi-Gang Shao

Journal of Electrochemistry

The development of efficient and durable electrodes for anion exchange membrane water electrolyzers (AEMWEs) is essential for hydrogen production. In this work, 2D NiFe layered double hydroxides (NiFe LDHs) nanosheets were grown on the 1D cobaltous carbonate hydroxide nanowires array (Co-OH-CO₃) and the unique 3D layered self-supporting nanorod array (NiFe LDHs@Co-OH-CO₃/NF) electrode was obtained. Importantly, we demonstrated an efficient and durable self-supporting NiFe LDHs@Co-OH-CO₃/NF electrode for oxygen evolution reaction (OER) and as the anode of the AEMWE. In a three-electrode system, the self-supporting NiFe LDHs@Co-OH-CO₃/NF electrode showed excellent catalytic activity for OER, …

A Co Porphyrin With Electron-Withdrawing And Hydrophilic Substituents For Improved Electrocatalytic Oxygen Reduction, Hong-Bo Guo, Ya-Ni Wang, Kai Guo, Hai-Tao Lei, Zuo-Zhong Liang, Xue-Peng Zhang, Rui Cao

Journal of Electrochemistry

Understanding factors that influence the catalyst activity for oxygen reduction reaction (ORR) is essential for the rational design of efficient ORR catalysts. Regulating catalyst electronic structure is commonly used to fine-tune electrocatalytic ORR activity. However, modifying the hydrophilicity of catalysts has been rarely reported to improve ORR, which happens at the liquid/gas/solid interface. Herein, we report on two Co porphyrins, namely, NO₂-CoP (Co complex of 5,10,15,20-tetrakis(4-nitrophenyl)porphyrin) and 5F-CoP (Co complex of 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin), and their electrocatalytic ORR features. By simultaneously controlling the electronic structure and hydrophilic property of the meso-substituents, the NO₂-CoP showed higher electrocatalytic activity than …

Surface Structure Engineering Of Feni-Based Pre-Catalyst For Oxygen Evolution Reaction: A Mini Review, Jia-Xin Li, Li-Gang Feng

Journal of Electrochemistry

Nitrite, a widespread raw material, is harmful to human health for long-term consumption. At present, the detection methods of nitrite mainly include chemical analysis, fluorescence, ultraviolet spectrophotometry and chromatography. These methods have ideal sensitivity and selectivity, but also have some characteristics: cumbersome operation, expensive equipment and professional personnel. Therefore, the development of a simple and sensitive nitrite assay is of great significance. In this paper, the Au/rGO/FeOOH composite materials, which revealed good synergistic catalytic performance among the three elements in the composite, were prepared by simple hydrothermal method and reduction method for the first time with large specific surface area …

The Life And Death Of Organic Electronics: Controlling Degradation And Regeneration Through Molecular Materials Design, Susanna Vu

Electronic Theses and Dissertations

Next-generation electronics will require conformability and stretchability to expand their integration in daily-life objects to be efficient energy and data storage. However, with the design and development of advanced technology comes the growing problem of electronic waste (e-waste). To tackle this growing challenge and access sustainable technologies, we suggest two routes for the fabrication of new electronics and enhancement of current technology that will reduce waste accumulation by using either degradable materials or regenerative materials. We propose the use of self-immolative polymers (SIPs) and self-healing polymers (SHPs) to control the lifetime and durability of various organic electronics through materials design. …

Perovskite-Type Water Oxidation Electrocatalysts, Xiao Liang, Ke-Xin Zhang, Yu-Cheng Shen, Ke Sun, Lei Shi, Hui Chen, Ke-Yan Zheng, Xiao-Xin Zou

Journal of Electrochemistry

The development of energy conversion/storage technologies can achieve the reliable and stable renewable energy supply, and bring us a sustainable future. As the core half-reaction of many energy-related systems, water oxidation is the bottleneck due to its sluggish kinetics of the four-concerted proton-electron transfer (CPET) process. This necessitates the exploitation of low cost, highly active and stable water oxidation electrocatalysts. Perovskite-type oxides possess diverse crystal structures, flexible compositions and unique electronic properties, enabling them ideal material platform for the optimization of catalytic performance. In this review, we provide a comprehensive summary for the crystal structures, electronic structures and synthetic methods …

Saturable Absorption Of Free-Electron Laser Radiation By Graphite Near The Carbon K-Edge, Lars Hoffmann, Sasawat Jamnuch, Craig P. Schwartz, Tobias Helk, Sumana L. Raj, Hikaru Mizuno, Riccardo Mincigrucci, Laura Foglia, Emiliano Principi, Shervin Fatehi

Chemistry Faculty Publications and Presentations

The interaction of intense light with matter gives rise to competing nonlinear responses that can dynamically change material properties. Prominent examples are saturable absorption (SA) and two-photon absorption (TPA), which dynamically increase and decrease the transmission of a sample depending on pulse intensity, respectively. The availability of intense soft X-ray pulses from free-electron lasers (FELs) has led to observations of SA and TPA in separate experiments, leaving open questions about the possible interplay between and relative strength of the two phenomena. Here, we systematically study both phenomena in one experiment by exposing graphite films to soft X-ray FEL pulses of …

Interpretable Machine Learning Models For Molecular Design Of Tyrosine Kinase Inhibitors Using Variational Autoencoders And Perturbation-Based Approach Of Chemical Space Exploration, Keerthi Krishnan, Ryan Kassab, Steve Agajanian, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

In the current study, we introduce an integrative machine learning strategy for the autonomous molecular design of protein kinase inhibitors using variational autoencoders and a novel cluster-based perturbation approach for exploration of the chemical latent space. The proposed strategy combines autoencoder-based embedding of small molecules with a cluster-based perturbation approach for efficient navigation of the latent space and a feature-based kinase inhibition likelihood classifier that guides optimization of the molecular properties and targeted molecular design. In the proposed generative approach, molecules sharing similar structures tend to cluster in the latent space, and interpolating between two molecules in the latent space …

Wastewater-Informed Public Health Intervention Playbook

Sustain Magazine

As the SARS-CoV-2 pandemic quickly spread from country to country and continent to continent in 2020, governments and scientists needed a way to track COVID-19 through populations in order to position public health interventions in the most impactful locations. Having a decision-based risk framework may help to guide policy creation that could minimize or prevent possible outbreaks and surges of infection within communities. The University of Louisville in partnership with Louisville’s Department of Public Health and Wellness tested this strategy in 2021 and 2022. This Wastewater-Informed Public Health Intervention Playbook describes the decisions and actions of that academic and public …

Electrospun Poly(3-Hydroxybutyrate-Co-3-Hydroxyvalerate)/Olive Leaf Extract Fiber Mesh As Prospective Bio-Based Scaffold For Wound Healing, Jose Gustavo De La Ossa, Serena Danti, Jasmine Esposito Salsano, Bahareh Azimi, Veronika Tempesti, Niccoletta Barbani, Maria Digiacomo, Marco Macchia, Mohammed Jasim Uddin, Caterina Cristallini

Chemistry Faculty Publications and Presentations

Polyhydroxyalkanoates (PHAs) are a family of biopolyesters synthesized by various microorganisms. Due to their biocompatibility and biodegradation, PHAs have been proposed for biomedical applications, including tissue engineering scaffolds. Olive leaf extract (OLE) can be obtained from agri-food biowaste and is a source of polyphenols with remarkable antioxidant properties. This study aimed at incorporating OLE inside poly(hydroxybutyrate-co-hydroxyvalerate) (PHBHV) fibers via electrospinning to obtain bioactive bio-based blends that are useful in wound healing. PHBHV/OLE electrospun fibers with a size of 1.29 ± 0.34 µm were obtained. Fourier transform infrared chemical analysis showed a uniform surface distribution of hydrophilic -OH groups, confirming the …

Pressure-Induced Modifications To The Structural And Optoelectronic Properties Of 2d Hybrid Organic-Inorganic Perovskites, Jesse Ratte

Electronic Thesis and Dissertation Repository

Recently, 2D hybrid organic-inorganic perovskites (HOIP) have garnered lots of research interest for their applications in optoelectronic devices, especially in solar cells. The optoelectronic properties of 2D HOIPs have yet to be optimized for these applications. High external pressure is well known to induce structural modifications to 2D HOIPs, and thus modify their optoelectronic properties. Herein, we report a study of the effects of high pressure (HP) on the structures and optoelectronic properties of cyclohexane methylamine (CMA) lead iodide (CMA2PbI4) and the structures of N,N-dimethylphenylene-p-diammonium (DPDA) lead iodide (DPDAPbI4).

High pressure measurements of CMA2PbI4 were performed using Raman spectroscopy, Fourier-transform …