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Mechanochemical Investigation Of A Glassy Epoxy-Amine Thermoset Subjected To Fatigue, Stephen F. Foster Mr. 2015 The University of Southern Mississippi

Mechanochemical Investigation Of A Glassy Epoxy-Amine Thermoset Subjected To Fatigue, Stephen F. Foster Mr.

Dissertations

Covalent bonds in organic molecules can be produced, altered, and broken through various sources of energy and processes. These include photochemical, thermochemical, chemical, and mechanochemical processes. Polymeric materials derive their physical properties from the time scale of motion, summation of intermolecular forces, and number of chain entanglements and crosslinks. Glassy thermoset polymers experience mechanical fatigue during dynamic stress loading and properties diminish with inevitable material failure at stress levels below the ultimate tensile strength (UTS). Damage modeling has been successful in predicting the number of cycles required to induce failure in a specimen due to stress. However, it does not ...


The Rational Design Of Selective Electrocatalysts For Renewable Energy Devices, Daniel F. Abbott 2015 Northeastern University

The Rational Design Of Selective Electrocatalysts For Renewable Energy Devices, Daniel F. Abbott

Chemistry Dissertations

The rational design of electrocatalysts is paramount to the development of electrochemical devices. In particular, modifications to the structure and electronic properties of a particular catalyst can have a strong influence on the activity and selectivity towards various electrochemical reactions or pathways. In many cases this can lead to a particular reaction pathway being opened or closed, the formation of intermediates being stabilized or inhibited, the adsorption of poisonous species being mitigated, or the removal of poisonous species being promoted. In the this dissertation the design and characterization of catalysts for electrochemical devices (fuel cells, electrolyzers, and hydrogen pumps) will ...


Optimized Acid/Base Extraction And Structural Characterization Of Β-Glucan From Saccharomyces Cerevisiae, Shardrack O. Asare 2015 East Tennessee State University

Optimized Acid/Base Extraction And Structural Characterization Of Β-Glucan From Saccharomyces Cerevisiae, Shardrack O. Asare

Electronic Theses and Dissertations

β-glucan is a major component of the fungal cell wall consisting of (1→3)-β linked glucose polymers with (1→6)-β linked side chains. The published classical isolation procedure of β-glucan from Saccharomyces cerevisiae is expensive and time-consuming. Thus, the aim of this research was to develop an effective procedure for the extraction of glucans. We have developed a new method for glucan extraction that will be cost effective and will maintain the native structure of the glucan. The method that we developed is 80% faster and utilizes 1/3 of the reagents compared to the published classical method ...


Molecular Mechanism For The Biosynthesis Of Antifungal Hsaf And Antibacterial Wap-8294a2, Haotong Chen 2015 University of Nebraska-Lincoln

Molecular Mechanism For The Biosynthesis Of Antifungal Hsaf And Antibacterial Wap-8294a2, Haotong Chen

Student Research Projects, Dissertations, and Theses - Chemistry Department

Bioactive natural products are a major source of anti-infectives. Many ubiquitous inhabitants of soil and water, such as the Gram-negative, prolific producers of natural products, Lysobacter, remain largely unexplored. This PhD thesis reports our studies of the biosynthetic mechanism for a novel antifungal natural product HSAF and a potent anti-MRSA natural product WAP-8294A2.

In the first chapter, we give a short review of the biosynthesis of polyketides, focusing on those which exhibit new biosynthetic features. In subsequent chapters, we present original research on the biosynthetic mechanisms of dihydromaltophilin, a heat stable antifungal factor (HSAF). HSAF is the main antifungal ...


Chromatographic Analysis Of Drug-Protein Interactions During Diabetes And Characterization Of Human Serum Albumin Through Multidimensional Mass Spectrometry, Ryan E. Matsuda 2015 University of Nebraska-Lincoln

Chromatographic Analysis Of Drug-Protein Interactions During Diabetes And Characterization Of Human Serum Albumin Through Multidimensional Mass Spectrometry, Ryan E. Matsuda

Student Research Projects, Dissertations, and Theses - Chemistry Department

Diabetes is a metabolic disease that can lead to the non-enzymatic glycation of serum proteins such as human serum albumin (HSA). Previous studies have indicated that glycation can affect the structure and function of these proteins. This dissertation describes the development of tools and techniques based on high performance affinity chromatography (HPAC) and multidimensional mass spectrometry to analyze the effects of glycation on the function and structure of HSA.

A major portion of this research involved the utilization of HPAC to examine the effect of glycation on the binding of three second-generation sulfonylurea drugs and one third-generation sulfonylurea drug. These ...


Analysis Of Free Solute Fractions And Solute-Protein Interactions Using Ultrafast Affinity Extraction And Affinity Microcolumns, Xiwei Zheng 2015 University of Nebraska-Lincoln

Analysis Of Free Solute Fractions And Solute-Protein Interactions Using Ultrafast Affinity Extraction And Affinity Microcolumns, Xiwei Zheng

Student Research Projects, Dissertations, and Theses - Chemistry Department

This dissertation describes the use of a high-performance affinity chromatography method based on ultrafast affinity extraction and microcolumns to study biological interactions.

In the first project, a new method was created and based on ultrafast affinity extraction to determine both the dissociation rate constants (kd) and association equilibrium constants (Ka) for drug-protein interactions in solution. Various conditions to optimize the use of ultrafast affinity extraction for equilibrium and kinetic studies were considered.

The objective of the next portion of this dissertation was to develop a chromatographic approach to measure free drug fractions in more complex samples. This was ...


Investigation Of The Alkaline Electrochemical Interface And Development Of Composite Metal/Metal-Oxides For Hydrogen And Oxygen Electrodes, Michael Kenneth Bates 2015 Northeastern University

Investigation Of The Alkaline Electrochemical Interface And Development Of Composite Metal/Metal-Oxides For Hydrogen And Oxygen Electrodes, Michael Kenneth Bates

Chemistry Dissertations

Understanding the fundamentals of electrochemical interfaces will undoubtedly reveal a path forward towards a society based on clean and renewable energy. In particular, it has been proposed that hydrogen can play a major role as an energy carrier of the future. To fully utilize the clean energy potential of a hydrogen economy, it is vital to produce hydrogen via water electrolysis, thus avoiding co-production of CO2 inherent to reformate hydrogen. While significant research efforts elsewhere are focused on photo-chemical hydrogen production from water, the inherent low efficiency of this method would require a massive land-use footprint to achieve sufficient ...


Synthetic Approaches Towards A Radiofluorinated Agent For Imaging Alzheimer's Disease, Tracy Chang 2015 Northeastern University

Synthetic Approaches Towards A Radiofluorinated Agent For Imaging Alzheimer's Disease, Tracy Chang

Chemistry Master's Theses

Alzheimer's Disease (AD) is a neurodegenerative disease in which the patient's memory slowly declines, accompanied by general physical degeneration and death. There are several hypotheses about the cause of AD, one of them being the aggregation of amyloid beta (Aβ) protein. Currently, the only way to definitively identify AD is by postmortem autopsy, in which the Aβ plaque is clearly identified. A potential noninvasive method for early diagnosis is a radiotracer for imaging Aβ deposits in the brain using positron emission tomography (PET) or single photon emission computer tomography (SPECT).

The Vasdev group has proposed alternative radio-fluorinated tracers ...


Discovery Of Unknown Modifications In Recombinant Monoclonal Antibodies, Christopher Michael Chumsae 2015 Northeastern University

Discovery Of Unknown Modifications In Recombinant Monoclonal Antibodies, Christopher Michael Chumsae

Chemistry Dissertations

Recombinant monoclonal antibodies have become one of the most important classes of biotherapeutics today. Due to their complexity, they must be produced by cellular expression. They are subject to various posttranslational modifications during manufacture, formulation and storage. Occasionally, the antibody may encounter a reactive molecule which in turn, results in a new variant. The application of modern analytical strategies including charge-based approaches and mass spectrometry in a defined workflow can effectively elucidate the presence of new species and help to understand the chemistry and underlying root cause. This dissertation will discuss the discovery of three novel chemical modifications in a ...


Synthesis Of Se-Adenosyl-L-Selenohomocysteine Selenoxide And Potential Gram-Negative Antibacterial Analogs, Dillon Christian Cleary 2015 Northeastern University

Synthesis Of Se-Adenosyl-L-Selenohomocysteine Selenoxide And Potential Gram-Negative Antibacterial Analogs, Dillon Christian Cleary

Chemistry Master's Theses

This paper includes work performed on two separate projects. The first project is the synthesis and characterization of a new analog of S-adenosylmethionine (AdoMet or SAM) called Se-adenosyl-L-selenohomocysteine selenoxide (SeAHO). This work outlines the total synthesis starting from adenosine and the characterization data collected along the way. This work culminated with the first successful synthesis of the desired selenoxide analog that can now be studied further for its potential biological activity. The second project involves medicinal chemistry efforts in synthesizing analogs of the oxazolidinone scaffold with desirable characteristics for potential treatment of Gram-negative bacterial infections. The oxazolidinone scaffold has already ...


Synthesis And Characterization Of Five New Tetrakis(N-Phenylacetamidato) Dirhodium(Ii) Amine Complexes And One Molybdenum Cofactor Described Crystallographically, Cragin K. Harris 2015 East Tennessee State University

Synthesis And Characterization Of Five New Tetrakis(N-Phenylacetamidato) Dirhodium(Ii) Amine Complexes And One Molybdenum Cofactor Described Crystallographically, Cragin K. Harris

Electronic Theses and Dissertations

Six new crystal structures were determined using a Rigaku Mercurcy 375/MCCD(XtaLab mini) diffractometer. The structure of a molybdenum cofactor was solved resulting in an R1 (R1 = Σ ||Fo| - |Fc|| / Σ |Fo|) of 3.61% despite the presence of a disordered DMSO molecule. New Tetrakis(N-phenylacetamidato) Dirhodium(II) complexes were synthesized and characterized. Two 2,2-cis-[Rh2(NPhCOCH3)4]•(C3H4N2)x where x= 1 or 2 were successfully crystallized and solved with R1 values below 5%. Additional studies were conducted via NMR to observe formation of both products. Three potential catalysts were synthesized starting with 3,1-[Rh2 ...


Study Of Mechanical Properties Of Pva Fiber-Reinforced Concrete With Raman Spectroscopic Analysis, Ramyasree Annam 2015 Western Kentucky University

Study Of Mechanical Properties Of Pva Fiber-Reinforced Concrete With Raman Spectroscopic Analysis, Ramyasree Annam

Masters Theses & Specialist Projects

The brittleness of concrete has always been a safety and economic issue of great concern. The low tensile strength of concrete is the cause of its intrinsic brittle nature. This is critical considering the amount of concrete used for the construction of highways, buildings, and other facilities. The mechanical properties of concrete must be improved to provide upgraded construction. Crack resistant and durable concrete has always been a major goal for engineers. Many approaches have been tried to make concrete a better construction material. Fiber reinforcement is an approach which has been shown to improve the quality and durability of ...


Investigations Into The Molecular Mechanisms Of Bacterial Pathogen-Host Interactions: Construction Of A Dual Plasmid System For Incorporation Of Unnatural Amino Acids Into Pseudomonas Syringae Pv. Tomato Dc3000, Scotty D. Raber 2015 University of Nebraska-Lincoln

Investigations Into The Molecular Mechanisms Of Bacterial Pathogen-Host Interactions: Construction Of A Dual Plasmid System For Incorporation Of Unnatural Amino Acids Into Pseudomonas Syringae Pv. Tomato Dc3000, Scotty D. Raber

Student Research Projects, Dissertations, and Theses - Chemistry Department

A dual plasmid system for the incorporation of unnatural amino acids into plant pathogen, Pseudomonas syringae pv. tomato DC3000, has been designed. This invention is expected to allow (a) mutations of proteins synthesized by the bacterium, P. syringae pv. tomato DC3000, that can capture molecular targets, especially for such modified proteins secreted by the phytopathogen into the host plant cells of A. thaliana and S. lycopersicum, (b) expression of biological probes in the bacterial species to monitor changes in redox, nutritional, and other small molecule states over pre-, post- and in situ disease stages, and (c) secretion of such biological ...


The 8-Silyloxyquinoline Scaffold As A Versatile Platform For The Sensitive Detection Of Aqueous Fluoride, Xinqi Zhou 2015 University of Nebraska-Lincoln

The 8-Silyloxyquinoline Scaffold As A Versatile Platform For The Sensitive Detection Of Aqueous Fluoride, Xinqi Zhou

Student Research Projects, Dissertations, and Theses - Chemistry Department

As one of the most essential elements in nature, fluoride has been well known and extensively studied since the 16th century. Since then the two-edged nature of fluoride in biological systems has been well described. Specifically, moderate fluoride exposure can aid in tooth and bone development, while fluoride overexposure results in the depilating disease known as fluorosis. Because of the side effects upon overexposure of fluoride, there is a need to develop fast and straight forward methods to sensitively and selectively detect and quantify fluoride concentration in drinking water. With this goal in mind and by taking advantage of ...


Toward The Measurement Of Biodistribution Of 18F-Labeled Industrial Chemicals With Positron Emission Tomography (Pet), Katelyenn S. McCauley 2015 University of Nebraska-Lincoln

Toward The Measurement Of Biodistribution Of 18F-Labeled Industrial Chemicals With Positron Emission Tomography (Pet), Katelyenn S. Mccauley

Student Research Projects, Dissertations, and Theses - Chemistry Department

Plasticizers are added to polymeric materials to increase flexibility and durability, thus they constitute a common, and widely used class of industrial chemicals. Plasticizers have been suspected of a number of adverse health effects including the interference with the endocrine system.1 These substances have the tendency to migrate to the surfaces of materials, where they can be absorbed, ingested, or inhaled. 5 The iniquitousness of plasticizers and the daily contact with polymeric materials has given rise to concern about the toxicity and health effects of these substances. Many long-term and excessive-dose studies have been conducted on many of these ...


Design, Synthesis, And Reactivity Of Bimetallic Complexes Of Dimethylplatinum(Ii) Containing Ditopic Ligands, Matthew S. McCready 2015 The University of Western Ontario

Design, Synthesis, And Reactivity Of Bimetallic Complexes Of Dimethylplatinum(Ii) Containing Ditopic Ligands, Matthew S. Mccready

University of Western Ontario - Electronic Thesis and Dissertation Repository

This thesis describes a study of monometallic and bimetallic dimethylplatinum(II) complexes containing ditopic nitrogen donor ligands. This work details the design and synthesis of side-to-side and cofacial arranged ligands and their respective coordination chemistry. The study of the synthesis, characterization and reaction mechanisms of the various dimethylplatinum(II) complexes is outlined in detail with special emphasis focused on the reactivity of the complexes towards oxidative addition.

The ditopic ligand 6-dppd, 1,4-di(2-pyridyl)-5,6,7,8,9,10-hexahydrocycloocta[d]pyridazine, was observed to coordinate only a single equivalent of a platinum(II) center. The inability to coordinate a ...


Flavour Chemicals In Electronic Cigarette Fluids, Peyton A. Tierney, Clarrissa D. Karpinski, Jessica E. Brown, Wentai Luo, James F. Pankow 2015 Portland State University

Flavour Chemicals In Electronic Cigarette Fluids, Peyton A. Tierney, Clarrissa D. Karpinski, Jessica E. Brown, Wentai Luo, James F. Pankow

Chemistry Faculty Publications and Presentations

Background: Most e-cigarette liquids contain flavour chemicals. Flavour chemicals certified as safe for ingestion by the Flavor Extracts Manufacturers Association may not be safe for use in e-cigarettes. This study identified and measured flavour chemicals in 30 e-cigarette fluids.

Methods: Two brands of single-use e-cigarettes were selected and their fluids in multiple flavour types analysed by gas chromatography/mass spectrometry. For the same flavour types, and for selected confectionary flavours (eg, bubble gum and cotton candy), also analysed were convenience samples of e-cigarette fluids in refill bottles from local ‘vape’ shops and online retailers.

Results: In many liquids, total flavour ...


Imidazolium Salts As Reaction Media For The Preparation Of Metal Halide Cluster Networks, Stephanie K. Gnewuch 2015 Otterbein University

Imidazolium Salts As Reaction Media For The Preparation Of Metal Halide Cluster Networks, Stephanie K. Gnewuch

Honor's Papers

This study investigated two different schemes of imidazolium and carboxylate salts to assess their use in preparing metal halide cluster networks. The first scheme used salts of 1-ethyl-3-methylimidazolium [EMIM]+ and 1-butyl-3-methylimidazolium [BMIM]+ as the cations and benzene-1,3,5-tricarboxylate [TMA]-, benzene 1,3-dicarboxylate [IPA]-, and benzene-1,4-dicarboxylate [TPA]- as the anions. The anions are commonly used in porous inorganic materials synthesis, as the size of the cation has been shown to often impact the final structure of the materials. The anions are common bridging ligands used to create network solids. The second scheme used 1,3-dimethylimidazolium triflate [DMIM]+ [OTf]- and ...


13c Nmr Spectroscopy: Transmission Effects In 3,5-Diaryl-4-Bromoisoxazoles, Beatrice Edjah, Jiyao Yu, Joseph Akinoso, Julia Dave, Hector Argueta-Gonzalez, Patrick Gaulden 2015 Georgia State University

13c Nmr Spectroscopy: Transmission Effects In 3,5-Diaryl-4-Bromoisoxazoles, Beatrice Edjah, Jiyao Yu, Joseph Akinoso, Julia Dave, Hector Argueta-Gonzalez, Patrick Gaulden

Georgia State Undergraduate Research Conference

No abstract provided.


Essential Oils From Apple Mint (Mentha Suaveolens) And Passionflower Fruit (Passiflora Incarnata): Studies On Cognition, Coordination, And Chemical Components., Evelyn F. Patrick *, Jessie Bowers *, Shannon Read *, Brett R. Lackey, Christine Murphy, Sandra L. Gray 2015 Endocrine Physiology Lab, Clemson University

Essential Oils From Apple Mint (Mentha Suaveolens) And Passionflower Fruit (Passiflora Incarnata): Studies On Cognition, Coordination, And Chemical Components., Evelyn F. Patrick *, Jessie Bowers *, Shannon Read *, Brett R. Lackey, Christine Murphy, Sandra L. Gray

Journal of the South Carolina Academy of Science

Plant essential oils (EO) are used as perfumes, lotions and air fresheners because of their pleasant aromas, but EO also have the ability to elicit changes in mood and behavior. These activities are influenced by the mode of administration and by multiple signaling pathways. The EO aromas from organically grown apple mint (Mentha suaveolens) and passionflower fruit (Passiflora incarnata) were assessed for their effects on cognition and coordination. Participants completed two tasks designed to test working memory and bimanual task efficiency in rooms infused with apple mint, passionflower fruit or control EO. Bimanual coordination was assessed using the Intercept2 program ...


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