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2019

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Articles 181 - 210 of 1773

Full-Text Articles in Chemistry

Nickel Selenide Derived From [Ni(En)3](Seo3) Complex For Efficient Electrocatalytic Overall Water Splitting, Dan-Dan Chen, Xue-Qing Gao, Hong-Fei Liu, Wei Zhang, Rui Cao Oct 2019

Nickel Selenide Derived From [Ni(En)3](Seo3) Complex For Efficient Electrocatalytic Overall Water Splitting, Dan-Dan Chen, Xue-Qing Gao, Hong-Fei Liu, Wei Zhang, Rui Cao

Journal of Electrochemistry

Electrocatalytic water splitting is considered as a promising technology for renewable energy. The development of efficient, stable, cost-effective, and bifunctional catalysts for both water reduction and oxidation has continued to face significant challenges. Herein, we report a robust and highly active nickel selenide (NiSe) spheres grown on carbon cloth (CC) by electrodeposition from a nickel selenite complex which is a single source containing both Ni and Se. A combination of two chemicals containing, separately, Ni and Se is used in traditional preparations of metal selenides, causing possible problems in the uniformity of the products. The as-prepared NiSe-EA/CC electrode exhibited electrocatalytic …


Special Issue: Electrocatalysis And Fuel Cells, Shuangyin Wang Oct 2019

Special Issue: Electrocatalysis And Fuel Cells, Shuangyin Wang

Journal of Electrochemistry

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A Facile Route To Synthesize Pt-Wo3 Nanosheets With Enhanced Electrochemical Performance For Her, Peng-Jie Jiang, Yi Lv, Chang-Miao Chen, Hong-Cheng He, Yong Cai, Ming Zhang Oct 2019

A Facile Route To Synthesize Pt-Wo3 Nanosheets With Enhanced Electrochemical Performance For Her, Peng-Jie Jiang, Yi Lv, Chang-Miao Chen, Hong-Cheng He, Yong Cai, Ming Zhang

Journal of Electrochemistry

Platinum-tungsten trioxide (Pt-WO3) nanosheets were synthesized on nickel foams (NFs) directly. As great conductive networks, NFs substrates could greatly improve the electrode performance of WO3. The modified platinum nanoparticles not only enhanced the electron transformation of catalysts, but also increased the active sites for hydrogen evolution reaction (HER). Pt-WO3/NF revealed a better catalytic activity than WO3/NFs with a smaller Tafel slope (80 mV·dec-1) and a lower overpotential of 72 mV at the current density of 10 mA·cm-2. In addition, Pt-WO3/NF showed great durability and stability during …


Three-Dimensional Porous Vn Octahedron Catalyst With High Electrocatalytic Efficiency Toward Hydrogen Evolution Reaction, Can Yin, Wei-Wei Fu, Ling Fang, Shi-Li You, Hui-Juan Zhang, Yu Wang Oct 2019

Three-Dimensional Porous Vn Octahedron Catalyst With High Electrocatalytic Efficiency Toward Hydrogen Evolution Reaction, Can Yin, Wei-Wei Fu, Ling Fang, Shi-Li You, Hui-Juan Zhang, Yu Wang

Journal of Electrochemistry

With the rapid development of China’s economy, the demand for energy is increasing, and environmental problems are becoming more and more serious. The development and utilization of highly-clean new energy fuel can effectively alleviate the energy crisis and environmental pollution. Nowadays, exploring high-efficiency, environment-friendly and low-cost catalysts remains the focus of research in the hydrogen evolution reaction (HER). In this research, firstly, we proposed a three-dimensional porous vanadium nitride (VN) with octahedral structure, which was prepared by a calcination treatment method. The VN catalyst showed a good electrocatalytic activity toward HER, involving a small overpotential of 94.0 mV at -10 …


Influences Of Morphology And Nitrogen Doping On The Electrocatalytic Characteristics For Oxygen Reduction Reaction Of Nio/Rgo, Dong Liang, Heng-Yi Fang, Shuo Yao, Jie-Mei Yu, Zhao-Liang Zhang, Zhan-Kun Jiang, Xue-Ping Gao, Tai-Zhong Huang Oct 2019

Influences Of Morphology And Nitrogen Doping On The Electrocatalytic Characteristics For Oxygen Reduction Reaction Of Nio/Rgo, Dong Liang, Heng-Yi Fang, Shuo Yao, Jie-Mei Yu, Zhao-Liang Zhang, Zhan-Kun Jiang, Xue-Ping Gao, Tai-Zhong Huang

Journal of Electrochemistry

In this research, the reduced graphene oxide (rGO) supported sheet-like NiO (NiO/rGO) and spherical-like NiO (NiO/N-rGO) catalysts for oxygen reduction reaction (ORR) were prepared. The structures, morphologies and chemical states of the two catalysts were characterized by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The electrochemical catalytic performance of the two catalysts for ORR were investigated by cyclic voltammetry (CV), Tafel, linear sweeping voltammetry (LSV), rotating disc electrode (RDE) and rotating ring disc electrode (RRDE) tests. Electrochemical results showed that the current density and onset potential (about 0.89 V) …


Preparations And Electrochemical Properties Of Co@Nc Nanocomposites Based On Zif-67, Xiao-Li Tan, Deng-Hong He, Xing-Wang Zhang Oct 2019

Preparations And Electrochemical Properties Of Co@Nc Nanocomposites Based On Zif-67, Xiao-Li Tan, Deng-Hong He, Xing-Wang Zhang

Journal of Electrochemistry

It is necessary to develop an inexpensive catalyst for the replacement of precious metal catalysts (such as RuO2, IrO2). In this article, the metal organic framework ZIF-67 was synthesized by solvothermal method at room temperature, and then the high temperature carbonization was used to prepare the nitrogen-doped carbon-based composite material Co@NC with the Co nanoparticle inside. The effects of the carbonization temperature on surface morphology, chemcial composition and electrocatalytic property were investigated. Most importantly, the Co@NC catalyst with the best morphology and structure was synthesized, and its catalytic activity and stability toward oxygen evolution reaction (OER) …


Preparation Of Nanostructural Mno-Porous Graphene Hybrid Material By Thermally-Driven Etching Of Mno For Lithium-Air Batteries, Juan Yang, Jun-Wei Lang, Peng Zhang, Bao Liu Oct 2019

Preparation Of Nanostructural Mno-Porous Graphene Hybrid Material By Thermally-Driven Etching Of Mno For Lithium-Air Batteries, Juan Yang, Jun-Wei Lang, Peng Zhang, Bao Liu

Journal of Electrochemistry

In this paper, improving the surface morphology of graphene(GNSs) as designed concept. we describe a MnO/porous-graphene(MnO-PGNSs) was synthesized by a simple site-localized Mn2+ on GO (Mn-GO) by charge adsorption and then driving by high-temperature calcination, growing MnO nanoparticles and etching GNSs achieved on step. And Then focus on the key factors of influenced the etch hole formation are analyzed, founded the dispersion of Mn-GO; layer number of GO and calcination temperature also affected the formation of holes. In addition, the MnO-PGNSs as lithium-air battery cathode exhibits high reversible capacity compared with GNSs and PGNs and it is able to …


Investigations In Electrochemical Thermodynamic And Kinetic Properties Of As-Cast And As-Quenched Cemg10Ni2 Hydrogen Storage Alloys, Feng Hu, Li-Rong Luo, Yong-Zhi Li, Ting-Ting Zhai, Xin Zhao, Yang-Huan Zhang Oct 2019

Investigations In Electrochemical Thermodynamic And Kinetic Properties Of As-Cast And As-Quenched Cemg10Ni2 Hydrogen Storage Alloys, Feng Hu, Li-Rong Luo, Yong-Zhi Li, Ting-Ting Zhai, Xin Zhao, Yang-Huan Zhang

Journal of Electrochemistry

In order to improve the electrochemical hydrogen storage properties of CeMg10Ni2 alloy, the rapid quenching technology was used to prepare CeMg10Ni2 alloys with nano-crystalline and amorphous structure. The microstructures of as-cast and as-spinning sample were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The electrochemical hydrogen storage properties were investigated by an automatic galvanostatic charging/discharging, high rate discharging (HRD), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. The results revealed that the as-cast alloy was composed of multiphase structures. The as-quenched alloys were made up of nano-crystalline and/or amorphous structures, and the …


Great Success Of The 20Th National Conference On Electrochemistry In China (Changsha), Chinese Society Of Electrochemistry (Cse) Oct 2019

Great Success Of The 20Th National Conference On Electrochemistry In China (Changsha), Chinese Society Of Electrochemistry (Cse)

Journal of Electrochemistry

No abstract provided.


Pd Nanoparticles Supported On The Etched Ni Foams As High-Performance Electrocatalysts For Direct Ethanol Fuel Cells, Chi Zhang, Cheng-Fei Li, Gao-Ren Li Oct 2019

Pd Nanoparticles Supported On The Etched Ni Foams As High-Performance Electrocatalysts For Direct Ethanol Fuel Cells, Chi Zhang, Cheng-Fei Li, Gao-Ren Li

Journal of Electrochemistry

The development of non-Pt anode electrocatalysts with high activity and long-term durability at low cost for fuel cells still remains enormous challenge. Here we report the Pd nanoparticles supported on Ni foams etched by the mixed acids (HNO3+H2SO4+H3PO4+CH3COOH) (Pd/ME-NF) that are designed and fabricated as high-performance electrocatalysts for ethanol oxidation in alkaline media. Because of the advantages of large open space, fast electrolyte penetration/diffusion and rapid electron transfer process, the Pd/ME-NF catalysts exhibited significantly improved electrocatalytic activity and durability compared with the commercial Pd/C catalysts.


Fate Of The Organophosphate Insecticide, Chlorpyrifos, In Leaves, Soil, And Air Following Application, Supta Das, Kimberly J. Hageman, Madeleine Taylor, Sue Michelsen-Heath, Ian Stewart Oct 2019

Fate Of The Organophosphate Insecticide, Chlorpyrifos, In Leaves, Soil, And Air Following Application, Supta Das, Kimberly J. Hageman, Madeleine Taylor, Sue Michelsen-Heath, Ian Stewart

Chemistry and Biochemistry Faculty Publications

A field study was conducted to further our understanding about the fate and transport of the organophosphate insecticide, chlorpyrifos, and its degradation product, chlorpyrifos oxon. Leaf, soil and air sampling was conducted for 21 days after chlorpyrifos application to a field of purple tansy (Phacelia tanacetifolia). Air samples were collected using a high-volume air sampler (HVAS) and seven battery-operated medium-volume active air samplers placed around the field and on a 500-m transect extending away from the field. Chlorpyrifos was detected every day of the sampling period in all matrices, with concentrations decreasing rapidly after application. Chlorpyrifos oxon was …


Cross-Linked Poly(4-Vinylpyridine-N-Oxide) As A Polymer-Supported Oxygen Atom Transfer Reagent, Anna M. Bauer, Erin E. Ramey, Kjersti G. Oberle, Gretchen A. Fata, Chloe D. Hutchison, Christopher R. Turlington Oct 2019

Cross-Linked Poly(4-Vinylpyridine-N-Oxide) As A Polymer-Supported Oxygen Atom Transfer Reagent, Anna M. Bauer, Erin E. Ramey, Kjersti G. Oberle, Gretchen A. Fata, Chloe D. Hutchison, Christopher R. Turlington

Faculty Publications

Oxygen atom transfer (OAT) reagents are common in biological and industrial oxidation reactions. While many heterogeneous catalysts have been utilized in OAT reactions, heterogeneous OAT reagents have not been explored. Here, cross-linked poly(4-vinylpyridine-N-oxide), called x-PVP-N-oxide, was tested as a heterogeneous OAT reagent and its oxidation chemistry compared to its molecular counterpart, pyridine-N-oxide. The insoluble oxidant x-PVP-N-oxide demonstrated comparable reactivity to pyridine-N-oxide in direct oxidation reactions of phosphines and phosphites in acetonitrile, but x-PVP-N-oxide did not react in other solvents. The polymer backbone of x-PVP-N-oxide, however, allowed …


Biochar Enhances Nitrous Oxide Reduction In Acidic But Not In Near-Neutral Ph Soil, Engil Isadora Pujol Pereira, Jerome Lechot, Rafaela Feola Conz, Abmael Da Silva Cardoso, Johan Six Oct 2019

Biochar Enhances Nitrous Oxide Reduction In Acidic But Not In Near-Neutral Ph Soil, Engil Isadora Pujol Pereira, Jerome Lechot, Rafaela Feola Conz, Abmael Da Silva Cardoso, Johan Six

School of Earth, Environmental, & Marine Sciences Faculty Publications

We quantified nitrous oxide (N2O) fluxes and total denitrification (N2O + N2) in an acidic (Ferralsol) and a near-neutral pH soil (Cambisol) to determine whether biochar’s alkalinization effect could be the mechanism inducing potential reductions in N2O fluxes. In Ferralsol, decreases in N2O emissions and in the N2O to N2O + N2 ratio were observed in both biochar and lime treatments. In Cambisol, neither biochar nor lime decreased N2O emissions, despite significantly increasing soil pH. The abundance and community structure of nosZ gene-bearing microorganisms indicated that gene abundances did not explain biochar effects, but a higher diversity of nosZ gene-bearing …


Chemical Synthesis Of Oligosaccharides From Human Milk, Mithila Dulanjalee Bandara Weerasooriya Mudiyanselage Oct 2019

Chemical Synthesis Of Oligosaccharides From Human Milk, Mithila Dulanjalee Bandara Weerasooriya Mudiyanselage

Dissertations

Human milk oligosaccharides (HMO) are a family of structurally related glycans that are highly abundant in breast milk. Oligosaccharide fraction is the third largest solid component in human milk after lactose and lipids. There is an accumulating evidence that HMO can provide significant benefits to the breast-fed infants. However, understanding of the exact HMO functions is still incomplete due to the lack of individual compounds in sufficient quantities. Therefore, development of expeditious strategies for the chemical synthesis of HMO has been increasingly important. Among all the methods available for oligosaccharide synthesis, armed-disarmed strategy introduced by Fraser-Reid is based on chemoselective …


Quartz Crystal Microbalance Based Sensors For Detection And Discrimination Of Volatile Organic Compounds Using Ionic Materials, Stephanie R. Vaughan Oct 2019

Quartz Crystal Microbalance Based Sensors For Detection And Discrimination Of Volatile Organic Compounds Using Ionic Materials, Stephanie R. Vaughan

LSU Doctoral Dissertations

Volatile organic compounds (VOCs) are prevalent in everyday life, ranging from household chemicals, naturally occurring scents from common plants and animals, to industrial-scale chemicals. Many of these VOCs are known to cause adverse health and environmental effects and require regulation to prevent pollution. Detecting VOCs plays a critical role in food quality control, environmental quality control, medical diagnostics, and explosives detection. Thus, development of adequate sensing devices for detection and discrimination of VOCs is of great importance. In recent years, use of quartz crystal microbalance (QCM) based sensor arrays for analyses of VOCs has attracted significant interest. Detection of VOCs …


Development Of A Tunable Platform For The Study Of Geomacromolecular Matrices Using Controlled Radical Polymerization, Arjun Pandey Oct 2019

Development Of A Tunable Platform For The Study Of Geomacromolecular Matrices Using Controlled Radical Polymerization, Arjun Pandey

LSU Doctoral Dissertations

Soil is an important environmental component, and the study of soil processes have many practical implications such as improvement in agriculture, mitigation of climate change etc. The widespread use of Agricultural Chemicals (ACs) in modern agriculture has resulted in adverse effects in environment and human health mostly through contamination into food and water sources. Study of fate, bioavailability, and transport of ACs involves molecular level understanding of their interactions with soil. This can be challenging due to complex and heterogeneous nature of soil. One common approach used is the correlation of macroscopic properties of soil, (e.g. sorption) with empirical parameters …


Thioenamide Synthesis Inspired By Peptide Macrocycles, Joshua Allen Lutz Oct 2019

Thioenamide Synthesis Inspired By Peptide Macrocycles, Joshua Allen Lutz

LSU Doctoral Dissertations

Despite advances in medicine, antibiotic resistance threatens to return once preventable diseases to the human population. The microbisporicins are 24-amino acid antibiotic peptides belonging to the lantibiotic class, which pathogens have been slow to develop resistance. The uncommon post-translational modification S-[(Z)-2-aminovinyl]-D-cysteine (AviCys) is likely crucial to their activity, and appears in a small number of other peptides with compelling biological activities. Total synthesis of an AviCys-containing peptide has eluded the chemical community.

The primary challenge of AviCys synthesis is the construction of a thioenamide functional group. We demonstrate that acid-promoted reactions between an amide and …


High Functional Diversity Of Contaminated Soils From Liberty State Park, Nina M. Goodey Oct 2019

High Functional Diversity Of Contaminated Soils From Liberty State Park, Nina M. Goodey

Sustainability Seminar Series

Urban brownfields present an opportunity to study the functioning of degraded ecosystems. We investigated the soils of Liberty State Park in Jersey City, New Jersey, which once supported a major rail yard and port facility with docks for shipping cargo to New York City. ICP-MS and pyrolysis-GC-MS studies were used to show that our study site is contaminated with heavy metals and organic contaminants, including polycyclic aromatic hydrocarbons. We used fluorescence spectroscopy to measure soil enzymatic function at multiple locations within the brownfield and found the following types of sites: 1.) hotspots with high heavy metal concentrations and high extracellular …


Determination Of Cannabinoids, Cathinones, And Synthetic Fentanyls Using Wastewater-Based Epidemiology, Catherine O'Rourke, Bikram Subedi Oct 2019

Determination Of Cannabinoids, Cathinones, And Synthetic Fentanyls Using Wastewater-Based Epidemiology, Catherine O'Rourke, Bikram Subedi

Posters-at-the-Capitol

Unregulated new psychoactive substances (NPS) in “pure” or “preparation” forms are designed to mimic the effects of controlled substances, and are introduced and reintroduced in the market as a cheap substitute for established regulated drugs in quick succession to loophole the law enforcement efforts on combating drugs. For example, carfentanil, a synthetic opioid activates the opioid receptors similar to morphine but it is astoundingly potent compared to a typical drug of abuse (100 times more potent than fentanyl and 10,000 times more powerful than morphine). Based on the cost- and time-intensive forensic analysis, National Drug Early Warning System reported the …


Stacked Core-Shell & Self-Supported Nanorod Array Electrocatalysts For Pem Fuel Cells, Fatma Merve Yurtsever Oct 2019

Stacked Core-Shell & Self-Supported Nanorod Array Electrocatalysts For Pem Fuel Cells, Fatma Merve Yurtsever

Theses and Dissertations

Polymer electrolyte membrane fuel cell (PEMFC) is one of the most attractive technologies for clean, renewable energy in the twenty-first century. It has many advantages in terms of zero carbon emission, quiet operation mode, high power density, higher efficiency than Carnot engines, and it requires less warm-up & fast start-up time. However, oxygen reduction reaction (ORR) activity and stability are still significant issues for the next generation PEMFCs to increase its usage. In this study, we developed a new design of stacked core-shell nanorod array and self-supported composition graded Pt:Ni nanorod array electrocatalyst to improve ORR kinetics and catalyst stability. …


Chemistry And Biochemistry News, Georgia Southern University Oct 2019

Chemistry And Biochemistry News, Georgia Southern University

Biochemistry, Chemistry & Physics: News & Publications (2012-2023)

  • SERMACS 2019 - Chemistry on the Coast


Samarium-Activated La2hf2o7 Nanoparticles As Multifunctional Phosphors, Santosh K. Gupta, Maya Abdou, Jose P. Zuniga, Alexander A. Puretzky, Yuanbing Mao Oct 2019

Samarium-Activated La2hf2o7 Nanoparticles As Multifunctional Phosphors, Santosh K. Gupta, Maya Abdou, Jose P. Zuniga, Alexander A. Puretzky, Yuanbing Mao

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Recent developments in the field of designing novel nanostructures with various functionalities have pushed the scientific world to design and develop high-quality nanomaterials with multifunctional applications. Here, we propose a new kind of doped metal oxide pyrochlore nanostructure for solid-state phosphor, X-ray scintillator, and optical thermometry. The developed samarium-activated La2Hf2O7 (LHOS) nanoparticles (NPs) emit a narrow and stable red emission with lower color temperature and adequate critical distance under near-UV and X-ray excitations. When the LHOS NPs are exposed to an energetic X-ray beam, the Sm3+ ions situated at the symmetric environment get excited along with those located at the …


Ultrafast And Real-Time Dynamics Of Nanomaterials Studied By Advanced Spectroscopic Techniques, Jeewan Chaminda Ranasinghe Oct 2019

Ultrafast And Real-Time Dynamics Of Nanomaterials Studied By Advanced Spectroscopic Techniques, Jeewan Chaminda Ranasinghe

LSU Doctoral Dissertations

Ultrafast and nonlinear spectroscopies are used to study excited-state dynamics and monitor real-time growth dynamics of different types of nanomaterials. In the first study, the growth dynamics of colloidal gold-silver core-shell nanoparticles are studied using in situ second harmonic generation and extinction spectroscopy. The growth lifetimes are studied under different reaction conditions, resulting in different silver shell thicknesses, with spectral comparisons to finite-difference time-domain calculations. The results are consistent with a three-step growth process. During the first step of the nanoparticle growth reaction, rough and uneven surfaces are formed rapidly giving rise to plasmonic hot spots with corresponding broad, red-shifted …


Experimental And Computational Electrochemistry Of Quinazolinespirohexadienone Molecular Switches – Differential Electrochromic Vs Photochromic Behavior, Eric W. Webb, Jonathan P. Moerdyk, Kyndra B. Sluiter, Benjamin J. Pollock, Amy L. Speelman, Eugene J. Lynch, William F. Polik, Jason G. Gillmore Oct 2019

Experimental And Computational Electrochemistry Of Quinazolinespirohexadienone Molecular Switches – Differential Electrochromic Vs Photochromic Behavior, Eric W. Webb, Jonathan P. Moerdyk, Kyndra B. Sluiter, Benjamin J. Pollock, Amy L. Speelman, Eugene J. Lynch, William F. Polik, Jason G. Gillmore

Faculty Publications

Our undergraduate research group has long focused on the preparation and investigation of electron-deficient analogs of the perimidinespirohexadienone (PSHD) family of photochromic molecular switches for potential application as "photochromic photooxidants" for gating sensitivity to photoinduced charge transfer. We previously reported the photochemistry of two closely related and more reducible quinazolinespirohexadienones (QSHDs), wherein the naphthalene of the PSHD is replaced with a quinoline. In the present work, we report our investigation of the electrochemistry of these asymmetric QSHDs. In addition to the short wavelength and photochromic long-wavelength isomers, we have found that a second, distinct long-wavelength isomer is produced electrochemically. This …


There And Back Again: A Chemist Tale & The Lord Of The Ring Stands, Benjamin Blass Oct 2019

There And Back Again: A Chemist Tale & The Lord Of The Ring Stands, Benjamin Blass

Science Seminars

Students at universities and colleges are focused on achieving their degrees, but often wonder where their careers will take them once they leave the confines of the academic world. While some people’s careers are straight lines through to retirement, others are wandering paths that lead to unexpected outcomes and opportunities. In an effort to provide some insight into life after school. This lecture describes Dr. Blass’s career journey over his 25+ year career and highlights some of the lessons he learned along the way.


Aromatic Character Of [Au13]5+ And [Mau12]4+/6+ (M = Pd, Pt) Cores In Ligand Protected Gold Nanoclusters – Interplay Between Spherical And Planar Σ-Aromatics, Nikita Fedik, Alexander I. Boldyrev, Alvaro Muñoz-Castro Oct 2019

Aromatic Character Of [Au13]5+ And [Mau12]4+/6+ (M = Pd, Pt) Cores In Ligand Protected Gold Nanoclusters – Interplay Between Spherical And Planar Σ-Aromatics, Nikita Fedik, Alexander I. Boldyrev, Alvaro Muñoz-Castro

Chemistry and Biochemistry Faculty Publications

The most characteristic feature of planar π-aromatics is the ability to sustain a long-range shielding cone under a magnetic field oriented in a specific direction. In this article, we showed that similar magnetic responses can be found in σ-aromatic and spherical aromatic systems. For [Au13]5+, long-range characteristics of the induced magnetic field in the bare icosahedral core are revealed, which are also found in the ligand protected [Au25(SH)18]− model, proving its spherical aromatic properties, also supported by the AdNDP analysis. Such properties are given by the 8-ve of the structural core satisfying …


Changes In Pm2.5 Peat Combustion Source Profiles With Atmospheric Aging In An Oxidation Flow Reactor, Judith C. Chow, Junji Cao, Lung-Wen Anthony Chen, Xiaoliang Wang, Qiyuan Wang, Jie Tian, Steven Sai Hang Ho, Adam C. Watts, Tessa B. Carlson, Steven D. Kohl, John G. Watson Oct 2019

Changes In Pm2.5 Peat Combustion Source Profiles With Atmospheric Aging In An Oxidation Flow Reactor, Judith C. Chow, Junji Cao, Lung-Wen Anthony Chen, Xiaoliang Wang, Qiyuan Wang, Jie Tian, Steven Sai Hang Ho, Adam C. Watts, Tessa B. Carlson, Steven D. Kohl, John G. Watson

Environmental & Global Health Faculty Research

Smoke from laboratory chamber burning of peat fuels from Russia, Siberia, the USA (Alaska and Florida), and Malaysia representing boreal, temperate, subtropical, and tropical regions was sampled before and after passing through a potential-aerosol-mass oxidation flow reactor (PAM-OFR) to simulate intermediately aged (∼2 d) and well-aged (∼7 d) source profiles. Species abundances in PM2.5 between aged and fresh profiles varied by several orders of magnitude with two distinguishable clusters, centered around 0.1 % for reactive and ionic species and centered around 10 % for carbon. Organic carbon (OC) accounted for 58 %–85 % of PM2.5 mass in fresh profiles with …


Pyrenylpyridines: Sky-Blue Emitters For Organic Light-Emitting Diodes, Thenahandi Prasanthi Deepthika De Silva, Sang Gill Youm, Isiah M. Warner Oct 2019

Pyrenylpyridines: Sky-Blue Emitters For Organic Light-Emitting Diodes, Thenahandi Prasanthi Deepthika De Silva, Sang Gill Youm, Isiah M. Warner

Faculty Publications

A novel sky-blue-emitting tripyrenylpyridine derivative, 2,4,6-tri(1-pyrenyl)-pyridine (2,4,6-TPP), has been synthesized using a Suzuki coupling reaction and compared with three previously reported isomeric dipyrenylpyridine (DPP) analogues (2,4-di(1 pyrenyl)pyridine (2,4-DPP), 2,6-di(1-pyrenyl)pyridine (2,6-DPP), and 3,5-di(1-pyrenyl)-pyridine (3,5-DPP)). 0 revealed by single-crystal X-ray analysis and computational simulations, all compounds possess highly twisted conformations in the solid state with interpyrene torsional angles of 42.3 degrees-57.2 degrees. These solid-state conformations and packing variations of pyrenylpyridines could be correlated to observed variations in physical characteristics such as photo/thermal stability and spectral properties, but showed only marginal influence on electrochemical properties. The novel derivative, 2,4,6-TPP, exhibited the lowest degree …


Intrinsic Cleavage Inhibition By Thermophilic Type Ii-S Restriction Endonucleases, Dino Jake Ciccone Oct 2019

Intrinsic Cleavage Inhibition By Thermophilic Type Ii-S Restriction Endonucleases, Dino Jake Ciccone

Master of Science in Chemical Sciences Theses

Restriction endonucleases (REs) are the cornerstone research tools used in molecular biology and biotechnology. These enzymes are essential to several ground-breaking achievements, including DNA cloning, gene editing, and genome mapping. A subset of these enzymes, Type II-S restriction endonucleases (IISREs), cleave double-stranded DNA (dsDNA) not governed by sequence specificity, but rather at a fixed distance from their recognition sequence. These enzymes maintain complete cleavage promiscuity, allowing utilization in techniques such as Golden Gate assembly, Serial Analysis of Gene Expression (SAGE), and Restriction Endonuclease Protection, Selection, and Amplification (REPSA). However, laboratories generated evidence that intrinsically cleavage refractory sequences exist. Understanding the …


Medium-Dependent Antibacterial Properties And Bacterial Filtration Ability Of Reduced Graphene Oxide, Alexander Gusev, Olga Zakharova, Dmitry S. Muratov, Nataliia S. Vorobeva, Mamun Sarker, Iaroslav Rybkin, Daniil Bratashov, Evgeny Kolesnikov, Aleš Lapanje, Denis V. Kuznetsov, Alexander Sinitskii Oct 2019

Medium-Dependent Antibacterial Properties And Bacterial Filtration Ability Of Reduced Graphene Oxide, Alexander Gusev, Olga Zakharova, Dmitry S. Muratov, Nataliia S. Vorobeva, Mamun Sarker, Iaroslav Rybkin, Daniil Bratashov, Evgeny Kolesnikov, Aleš Lapanje, Denis V. Kuznetsov, Alexander Sinitskii

Department of Chemistry: Faculty Publications

Toxicity of reduced graphene oxide (rGO) has been a topic of multiple studies and was shown to depend on a variety of characteristics of rGO and biological objects of interest. In this paper, we demonstrate that when studying the same dispersions of rGO and fluorescent Escherichia coli (E. coli) bacteria, the outcome of nanotoxicity experiments also depends on the type of culture medium. We show that rGO inhibits the growth of bacteria in a nutrition medium but shows little eect on the behavior of E. coli in a physiological saline solution. The observed eects of rGO on E. coli in …