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Role Of Water On The Rotational Dynamics Of The Organic Methylammonium Cation: A First Principles Analysis, Ross D. Hoehn, Joseph S. Francisco, Sabre Kais, Ali Kachmar 2019 Purdue University

Role Of Water On The Rotational Dynamics Of The Organic Methylammonium Cation: A First Principles Analysis, Ross D. Hoehn, Joseph S. Francisco, Sabre Kais, Ali Kachmar

Faculty Publications -- Chemistry Department

Understanding the degradation mechanisms of lead-halide perovskites (CH3NH3PbI3) under exposure to liquid/aerosol water is an essential problem within the photovoltaic community. Herein we investigate both the static and the dynamic properties of the methylammonuim cation (MA) as it coordinates with invading water molecules (MA.(H2O)n, n = 1, 2, 3, 4) using both stationary state quantum mechanics and first principle molecular dynamics simulations. Various solvation structures of MA were characterized by their stabilization energies, dipoles, and Maximally-Localized Wannier Function (MLWF) centers. Calculation – and analysis – of vibrational shifts in the IR spectral region ...


A Review: Thermal Stability Of Methylammonium Lead Halide Based Perovskite Solar Cells, Tanzila Tasnim Ava, Abdullah Al Mamun, Sylvain Marsillac, Gon Namkoong 2019 Old Dominion University

A Review: Thermal Stability Of Methylammonium Lead Halide Based Perovskite Solar Cells, Tanzila Tasnim Ava, Abdullah Al Mamun, Sylvain Marsillac, Gon Namkoong

Electrical & Computer Engineering Faculty Publications

Perovskite solar cells have achieved photo-conversion efficiencies greater than 20%, making them a promising candidate as an emerging solar cell technology. While perovskite solar cells are expected to eventually compete with existing silicon-based solar cells on the market, their long-term stability has become a major bottleneck. In particular, perovskite films are found to be very sensitive to external factors such as air, UV light, light soaking, thermal stress and others. Among these stressors, light, oxygen and moisture-induced degradation can be slowed by integrating barrier or interface layers within the device architecture. However, the most representative perovskite absorber material, CH3 ...


Investigation Of Amyloid Β Oligomer Dissociation Mechanisms By Single Molecule Fluorescence Techniques, Hope Cook Abdalla 2019 University of Kentucky

Investigation Of Amyloid Β Oligomer Dissociation Mechanisms By Single Molecule Fluorescence Techniques, Hope Cook Abdalla

Theses and Dissertations--Chemistry

Alzheimer’s disease (AD) is currently considered the most prevalent neurodegenerative disease and places a large financial burden on society as healthcare resources are limited and the disease does not have a cure. Alzheimer’s disease is characterized by the presence of amyloid beta (Aβ) plaques and neurofibrillary tangles; however current literature suggests Aβ oligomers are the main aggregating species leading to AD symptoms. Therefore, the underlying cause of Alzheimer’s, accumulation of amyloid beta, is currently being studied in hopes of developing treatment options. Our research aims at determining the mechanism and kinetics of Aβ oligomer dissociation into non-toxic ...


Solar Cells, D. Venkataraman 2019 University of Massachusetts Amherst

Solar Cells, D. Venkataraman

Science and Engineering Saturday Seminars

Solar cells convert the sun's energy into electrical energy. In this workshop, I will discuss the processes involved in solar cell and various types of solar cells that are being developed as an alternative to silicon solar cells. I will also demonstrate how students can build a solar cell from readily available materials.


Inhibition Of Hsv-1 Binding By Egcg-Stearate, Valerie Paschalis 2019 Montclair State University

Inhibition Of Hsv-1 Binding By Egcg-Stearate, Valerie Paschalis

Theses, Dissertations and Culminating Projects

Herpes simplex virus type 1 (HSV-1) is the causative agent of oral herpes, and is able to establish lifelong latent infection along with painful, recurring symptoms. Epigallocatechin-3- gallate (EGCG) is the most abundant polyphenol derived from green tea (Camellia sinensis), whose anti-inflammatory, antioxidant, anti-cancer, and antiviral properties have been widely studied. Although EGCG is not chemically stable and has poor hydrophobicity, lipophilic derivatives of EGCG have shown increased stability as well as increased antiviral efficacy against HSV. Previous studies have demonstrated that EGCG stearate (EGCG-S), a derivative of EGCG esterified at the 4’ position with stearic acid, is able to ...


Call For Abstracts - Resrb 2019, July 8-9, Wrocław, Poland, Wojciech M. Budzianowski 2018 Wojciech Budzianowski Consulting Services

Call For Abstracts - Resrb 2019, July 8-9, Wrocław, Poland, Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.


Table Of Contents, 2018 University of South Carolina

Table Of Contents

Journal of the South Carolina Academy of Science

No abstract provided.


Controls On Phosphorus Export From An Agricultural Watershed: Amsden Brook, Fort Fairfield, Maine Usa., Gregory J. McDonald 2018 University of Maine

Controls On Phosphorus Export From An Agricultural Watershed: Amsden Brook, Fort Fairfield, Maine Usa., Gregory J. Mcdonald

Electronic Theses and Dissertations

This study explores the sources and mechanisms of phosphorus (P) mobilization during base flow within the Amsden Brook watershed, Fort Fairfield, Maine, USA. Amsden Brook is an agriculturally dominated watershed drained by a spring-fed and perennial first- to second-order stream. We characterized the P concentrations within the watershed to investigate connections between soils, stream sediment, surface water, and groundwater. Waters were monitored monthly during the 2017 snow-free period for temperature, pH, dissolved oxygen, conductivity, soluble reactive P (SRP), total P, strong acid anions, strong base cations, dissolved organic carbon (DOC), Al, Fe, and Mn. Phosphorus speciation within soils and sediment ...


Side Chain Modifications To Improve Peptide Structure–Activity Relations, Neelam Lahankar 2018 Seton Hall University

Side Chain Modifications To Improve Peptide Structure–Activity Relations, Neelam Lahankar

Seton Hall University Dissertations and Theses (ETDs)

While natural peptides, are ideal starting points for peptide-based drug design and development, they suffer from high conformational instability, which results in susceptibility to proteolytic degradation and poor bioavailability. Peptidomimetics in recent years has helped circumvent these shortcomings by improving the pharmacological properties of polypeptides. Peptidomimetics contain essential elements (pharmacophores) that mimic a natural peptide or protein in 3D space and retain the ability to interact with the biological target producing the same biological effect. In contrast, they offer conformationally restricted structures, potentially minimizing cross-target interactions, which leads to better transport properties through biologic membranes and resistance to immune responses ...


Syntheses Of A Tin (Iv) Meso-Tetra(4-Pyridyl) Porphyrin Dichloride-Tetrachlorobis (Bipy)2 Ruthenium (Ii) Complex And Studies Of Photophysical Properties Of 1-Nitropyrene, Phillip Sharp 2018 Stephen F. Austin State University

Syntheses Of A Tin (Iv) Meso-Tetra(4-Pyridyl) Porphyrin Dichloride-Tetrachlorobis (Bipy)2 Ruthenium (Ii) Complex And Studies Of Photophysical Properties Of 1-Nitropyrene, Phillip Sharp

Electronic Theses and Dissertations

Development of a photosensitizer that can work in both aerobic and anaerobic environments would increase the robustness of the cancer treatment known as photodynamic therapy. The development of a photosensitizer was first attempted by synthesizing a tin (IV) meso-tetra (4-pyridyl) porphyrin dichloride-tetrachlorobis (Bipy)2 ruthenium (II) complex. The synthesize of the tin porphyrin was done by a method from literature and had a percent error of 31.58 and 37.31 when comparing the theoretical percentages of carbon (55.39) and nitrogen (12.92) meaning that photosensitizer was not synthesized.

The second type of chromophore that was studied was 1-nitropyrene ...


Anodic Cyclization Reaction: Manipulation Of Reaction Pathway And Efforts To Radical Cation And Radical Intermediate, Ruozhu Feng 2018 Washington University in St. Louis

Anodic Cyclization Reaction: Manipulation Of Reaction Pathway And Efforts To Radical Cation And Radical Intermediate, Ruozhu Feng

Arts & Sciences Electronic Theses and Dissertations

In recent years, synthetic chemists have been expressing significant interest in electro-organic synthetic methods. This interest is being fueled by the existence of an increasing number of successful methods in the literature and the availability of new electrochemical equipment that removes the barrier to attempting an electrolysis reaction for the first time. Yet while these developments have fueled growth in some areas of electro-organic synthesis (the recycling of chemical catalysts for example), other areas remain underdeveloped. One such area is the exploration of reactions that can be triggered directly as an electrode surface without the use of any chemical reagent ...


Radiolabeled Nanohydroxyapatite As A Platform For The Development Of New Pet Imaging Agents, Stacy Lee Queern 2018 Washington University in St. Louis

Radiolabeled Nanohydroxyapatite As A Platform For The Development Of New Pet Imaging Agents, Stacy Lee Queern

Arts & Sciences Electronic Theses and Dissertations

Positron emission tomography (PET) imaging utilizes drugs labeled with positron emitters to target and evaluate different biological processes occurring in the body. Tailoring medicine to the individual allows for higher quality of care with better diagnosis and treatment and is a key purpose for advancing research into developing new platforms for PET imaging agents. A PET nuclide of high interest for the development of these agents is 89Zr. This can be attributed to the long half-life of 3.27 days and low positron energy of 89Zr.

In this work, we developed a production method for 89Zr using Y sputtered coins ...


Photophysical Characterization And Wavelength Tuning Of Natural And Synthetic Oxobacteriochlorins And Biohybrids, Don Hood 2018 Washington University in St. Louis

Photophysical Characterization And Wavelength Tuning Of Natural And Synthetic Oxobacteriochlorins And Biohybrids, Don Hood

Arts & Sciences Electronic Theses and Dissertations

ABSTRACT OF THE DISSERTATION

Photophysical Characterization and Wavelength Tuning of Natural and Synthetic Oxobacteriochlorins and Biohybrids

By

Donald L. Hood

Doctor of Philosophy in Chemistry

Washington University in St. Louis, 2018

Dr. Dewey Holten, Chairperson

Herein is discussed the theoretical and practical unpinnings of photophysical behaviors and kinetic constants for tetrapyrrole macrocycles, to wit, porphyrins, chlorins, and bacteriochlorins. Understanding the characteristic photophysical response of tetrapyrroles to changes in environment or substituents is important to designing synthetic chromophores with tunable absorption wavelengths and for preparing useful biohybrids of natural photosynthetic light antennas combined with unnatural chromophores attached to the light antenna ...


Photo-Isomerizable Complementary Hydrogen Bond Arrays, Jeffrey S. Pleizier 2018 The University of Western Ontario

Photo-Isomerizable Complementary Hydrogen Bond Arrays, Jeffrey S. Pleizier

Electronic Thesis and Dissertation Repository

The use of light as an external stimulus provides a non-invasive technique to induce large changes in physical and chemical properties of a substrate. The incorporation of a photochromic subunit into supramolecular polymeric systems therefore adds a potential "smart" quality for polymer manipulation. The azo moiety (-N=N-) is one of the most popular photochromic units as the trans to cis isomerization results in a large degree of spatial rearrangement. This present thesis exploits the azo group by its incorporation into complementary hydrogen bonded complexes. Hydrogen bonding acceptor groups attached to the periphery of the central azo photoswitch provided strong ...


Inequality, Rubber, And Thermodynamics In Indonesia, Ernest M. Oleksy 2018 Cleveland State University

Inequality, Rubber, And Thermodynamics In Indonesia, Ernest M. Oleksy

The Downtown Review

Intersectionality has led the charge in ensuring that workplace justice is assured to all people, irrespective of their identities. While intersectionality is a useful theory for explaining inequality, what must not be understated is the contributions that postcolonialism and the blue-collar working identity can have on harsh working conditions. Particularly, miners in Indonesia have had to work in very hostile environments where they are at-risk for sulfur poisoning as they mine for materials to vulcanize rubber. This article serves two purposes. The first is to call attention to how place can help explain the differential experiences of miners in the ...


The Chemical Causes And Social Effects Of Acid Rain, Ernest M. Oleksy 2018 Cleveland State University

The Chemical Causes And Social Effects Of Acid Rain, Ernest M. Oleksy

The Downtown Review

While global warming tends to dominate the collective conscious for environmentalism of academics and the public alike, many other physical phenomena bear serious implications for humanity's future. One such phenomenon, acid rain, has been under-reported considering how damaging it is to the ecosystem and how much politicking is involved when determining how to address it. This article serves two purposes. The first is to inform readers of the basic chemical processes underlying acid rain and why it is damaging to organisms. The second is to inform readers of how acid rain has been portrayed by other publications, like the ...


Copper Grafted Titanium Dioxide In Hydrogels For Photocatalysts, Salem Amsaaed 2018 Atlanta University Center

Copper Grafted Titanium Dioxide In Hydrogels For Photocatalysts, Salem Amsaaed

Electronic Theses & Dissertations Collection for Atlanta University & Clark Atlanta University

This study are based on the premise that the incorporation of metal ions into nano titania-PHEMA [poly (2-hydroxyethyl methacrylate)] hydrogels would enhance the desirable properties in the photodecomposition of pollutants. The investigation are centered in the use of Cu(II) as metal ion of interest. The development of TiO2-PHEMA-Cu hydrogels was conducted, and the characterization of the materials by FT-IR, XRD and fluorescence was performed. The absorption of copper(II) from the solution was monitored by UV-Vis. The FT-IR are found too, be the most effective tool too, analyze the interaction of Cu(II) with PHEMA in the ...


The Investigation Of The Chlorine Initiated Oxidation Of 2-Phenylethanol And Stability Of Superalkali Lithium Substituted Silyls., Adam Otten 2018 The University of San Francisco

The Investigation Of The Chlorine Initiated Oxidation Of 2-Phenylethanol And Stability Of Superalkali Lithium Substituted Silyls., Adam Otten

Master's Theses

This thesis investigates the combustion potential of 2-phenylethanol and the superalkali properties of small lithium substituted silicon compounds. All combustion experiments were performed at the Advanced Light Source of Lawrence Berkeley National Laboratory at the Chemical Dynamics Beamline 9.0.2. The chlorine initiated oxidation of 2PE was investigated at 298 and 550 K using a multiplex photoionization mass spectrometer, coupled with the tunable vacuum ultraviolet radiation. Reaction products were identified using kinetic time traces and photoionization spectra.

Additionally, the stability of small superalkali silicon-lithium compounds has also been investigated. All structures and energetics were calculated using the CBS-QB3 composite ...


Detection And Melting Of Surface-Bound Dna Using A Purely Electrochemical Approach, Denny Ho 2018 The University of San Francisco

Detection And Melting Of Surface-Bound Dna Using A Purely Electrochemical Approach, Denny Ho

Master's Theses

In this thesis, we demonstrate an electrochemical approach for monitoring the electric-field induced melting of surface-bound double-stranded DNA. The electrochemical routine involves repeated chronoamperometry pulses to melt the duplex and square wave voltammetry to monitor the extent of melting. We utilize a scanning potential and constant potential technique to generate melting curves and access the stability and kinetics of the DNA duplexes. Our method uses a mixed monolayer of thiol-modified DNA oligomers and mercaptohexanol on gold electrodes, are subsequently incubated with target DNA covalently modified with electroactive methylene blue. Under room temperature, 10 mM Tris, and optimized electrochemical parameters, DNA ...


Heat And Work, The First Law Of Thermodynamics From The Boltzmann Pov, Carl W. David 2018 University of Connecticut

Heat And Work, The First Law Of Thermodynamics From The Boltzmann Pov, Carl W. David

Chemistry Education Materials

The First Law of Thermodynamics is discussed in terms of the Boltzmann distribution.


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