Physical Sciences and Mathematics Commons^™

Burst Pressure Properties And Ex Vivo Analysis Of Alginate-Based Hydrogels For Tissue Sealant Applications, Patrick Nelson Charron

Graduate College Dissertations and Theses

Lung diseases, cancers, and trauma can result in injury to the connective tissue lining the lung, i.e., the pleura. Pleural injuries lead to pneumothoraxes or pleural effusions, i.e., air or fluid leaking out of the lung respectively, and potential lung collapse - an immediately life threatening condition. While several bioengineered soft tissue sealants exist on the market, there is only one sealant FDA-approved for use in pulmonary surgery. In addition, very limited techniques are presented in the literature for characterizing the burst properties of hydrogel tissue sealants. For my thesis, I proposed to develop a protocol for characterizing the burst …

Speciation Behavior Of Americium Higher Oxidation States For The Separation Of Americium From Curium, Catherine Lynn Riddle

UNLV Theses, Dissertations, Professional Papers, and Capstones

Several countries are currently expanding the use of nuclear energy as a method for the safe generation of carbon free energy and a number are evaluating starting up a nuclear power program. Closed fuel cycle technologies may be key to waste reduction and a sustainable nuclear energy future and to support the development of more efficient fuel cycles, the investigation of the chemical properties of key actinides is at the forefront of separations research. In this work the characterization of higher oxidation states of americium (Am) has been performed using spectroscopic methods. Americium in the formal oxidation state of Am(V) …

Anodic Strategies For The Covalent Attachment Of Molecules To Electrodes Through Ethynyl And Vinyl Linkages, Matthew Vincent Sheridan

Graduate College Dissertations and Theses

Substrates with localized, organic radicals have the ability to attack `inert' surfaces to form covalent bonds between the substrate and an atom at the surface. These radicals can be generated in electrochemical experiments with substrates bearing an electroactive moiety. The moiety after oxidation (loss of an electron) or reduction (gain of an electron) generates the active radical. Electron transfer reactions at an electrode surface generate a high population of these radicals, thereby facilitating attachment.

The electrochemical oxidations of compounds containing terminal alkynes and alkenes were found to be effective methods for covalent attachment to glassy carbon, gold, and platinum electrodes. …

Synthesis Of Novel Ionic Liquid Tagged Porphryin Media Designed For The Oxidation Of Lignin, Joseph Hugh Franklin Baker

Online Theses and Dissertations

The ever growing need for a viable renewable fuel source has led to this thesis project; the biomimetic lignin degradation by means of a homogeneous oxidative catalyst in corresponding ionic liquids. Lignin comprises nearly a third of lignocellulosic biomass and is cross-linked to both cellulose and hemicellulose. Current utilization methods of lignin do not generate the full value of the polymer, because they do not yield many of the valuable feed stock chemicals it is comprised of. To improve the value of the biomass as a whole and create a viable economy for the US's transition to biofuels, better utilization …

Molecular Characterization Of The Soluble Fraction Of Atmospheric Particulate Matter Obtained By Chemical Oxidation With Nitric Acid, Amanda Susan Priest

Chemistry & Biochemistry Theses & Dissertations

The availability of information regarding the composition of ambient atmospheric particulate matter and the transformations that these compounds may undergo upon atmospheric transit is surprisingly absent. Electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry is used in this study to rapidly evaluate the composition of the water-soluble organic fraction of standard and collected atmospheric particulate matter samples, and the changes that these mixtures undergo upon oxidation with nitric acid. The standard samples include representative particulate matter collected over the course of a year in Washington, D.C. and particulate matter from the exhaust of a diesel-powered engine. The collected sample …

Oxidation Of Dibenzothiophene To Dibenzothiophene Using Metal Nanoparticles Supported On Silica, Karina Castillo

Open Access Theses & Dissertations

Silica and nanoparticles of Pt, Au, and Ag supported on silica were tested for the ability to oxidize dibenzothiophene (DBT) to sulfone. High performance liquid chromatography was used to study the removal of DBT from solution. In addition, X- ray diffraction, infrared spectroscopy and Raman Spectroscopy were used to characterize the product of the oxidation reaction. Further studies involved the use X-ray absorption spectroscopy to characterize the nanoparticle catalysts before and after the oxidation reaction.

To better understand the reaction, silica was synthesized at different pHs using three different acids. The acids used to synthesize the silica were HCl, HNO3, …

A Theoretical Study Of Methanol Oxidation Mechanisms By Methanol Dehydrogenase Enzymes For Fuel Cell Applications, Nagesh B. Idupulapati

Doctoral Dissertations

Enzymes are considered for electrochemical generation of power in fuel cells. Methanol dehydrogenase (MDH) is one such enzyme, which has been used as an anodic catalyst for a methanol-fed biofuel cell producing enough power for small electronic device applications. In practice, however, there are power output limitations associated with this MDH fuel cell, which may potentially be eliminated or reduced if the reactivity of this enzyme during the oxidation of methanol at the molecular level is clearly understood.

Two mechanisms for the methanol oxidation process by MDH have been proposed in the literature, Addition-Elimination (A-E) and Hydride Transfer (H-T), but …

A Lab To Stemulate Undergraduate Students Into Science, Technology, Engineering And Mathematics Majors, Nicole Lynn Speelman

Browse all Theses and Dissertations

The central focus is the development and implementation of a research/lab module for first year chemistry courses. Electrochemical techniques are utilized to study oxidation and reduction reactions of neurotransmitters with a poly(2,2'-Bithiophene) modified electrode. The goal is to excite students about chemistry and encourage them to continue studies in Science, Technology, Engineering, and Mathematics (STEM) during their undergraduate education. The lab module was created for Project REEL (Research Experiences to Enhance Learning) and will be illustrated with results typically obtained by students. The experiment is inquiry-based, which includes challenging questions students have to do collaboration and research to answer, as …

Comparison Of The Electrochemical Properties Of Ethanol In Perchloric Acid And Ionic Liquids, Sandra Felix-Balderrama

Browse all Theses and Dissertations

1-Ethyl-3-Methylimidazolium Tetrafluroborate (EMImBF₄) and 1-Ethyl-3-Methylimidazlium Bis(trifluoromethanesulfonyl)imide (EMImTFSI) ionic liquids were synthesized and characterized in order to study the electrochemical oxidation of ethanol in these ionic liquids on a platinum surface electrode.

It was found that pure EMImBF₄ exhibits an electrochemical window of 4.4 V,while EMImTFSI exhibits an electrochemical window of 5.0 V.

Electrochemical study of ethanol in perchloric acid showed that the oxidation of ethanol strongly depends on the concentration of ethanol and on the temperature of the solution. The poisoning of the platinum electrode only depends on the concentration of ethanol. At a low concentration of …

Study Of Corrosion Of Materials In The Sulfur-Iodine Hydrogen Production Cycle, Thao Trung Ho

UNLV Theses, Dissertations, Professional Papers, and Capstones

Hydrogen is of great interest since the availability of traditional fossil fuels is in decline. Strictly speaking, hydrogen is not a primary source of energy but is an energy carrier, since energy typically must be used from another source (electricity, natural gas, coal, etc.) to produce it. Of hydrogen production techniques, the Sulfur-Iodine thermochemical water splitting process (S-I cycle), which was proposed by General Atomics (GA), is promising with its simplicity and high efficiency. Most of the chemicals are recycled except water. However, the S-I cycle operates in a harsh, corrosive environment in the presence of a mixture of iodine …

Mass Spectrometry-Based High Throughput Approach For Identification Of Molecular Modification Of Oxidative Process In Respiratory Diseases, Wei Song

ETD Archive

Eosinophil peroxidase (EPO) and myeloperoxidase (MPO) have been implicated in generating reactive species and promoting oxidative modifications in numerous diseases. The detection and identification of potential pathways has been proven extremely challenge due to evanescence nature of these reactive species. An alternative approach to study the involvement of oxidative modification is to detect and quantify the stable molecular fingerprints, like oxidized tyrosine species, in biological matrices. Previously reported analytical methods for quantifying oxidized amino acids have typically been limited by: low sensitivity, specificity and the failure of detection potential oxidation products generated during sample handling. Using GC/MS in combination with …

Kinetics And Mechanism Of Oxygen Delignification, Yun Ji

Electronic Theses and Dissertations

Considerable research has been conducted into the kinetics and selectivity of the oxygen delignification process to overcome limitation in its use. However most studies were performed in a batch reactor whereby the hydroxide and dissolved oxygen concentrations are changing during the reaction time in an effort to simulate tower performance in pulp mills. This makes it difficult to determine the reaction order of the different reactants in the rate expressions. Also the lignin content and cellulose degradation of the pulp are only established at the end of the experiment when the sample is removed from the batch reactor. To overcome …

Biochemical Investigations Of Macular Degeneration: The Significance Of Protein Oxidation Including Novel Methods For Its Study, Sarah Warburton

Theses and Dissertations

The retinal pigment epithelium (RPE) is a monolayer of cells located directly behind the photoreceptor cells in the retina. These cells are involved in a variety of functions that support the visual process in the eye, namely 1) they form a blood-retina barrier which separates the neural retina from the choroid's blood supply, 2) the apical processes of RPE cells diurnally phagocytose the outer segments of photoreceptor cells, and 3) they participate in the renewal of the photopigment 11-cis retinal. Age-related macular degneration (AMD) is the leading cause of blindness in people over the age of 50 years in North …

Oxidative Damage Caused By Iron Loading Into Ferritin, Talina Christensen Watts

Undergraduate Honors Capstone Projects

Ferritin is the iron storage protein found in humans, animals, plants, fungi and bacteria. We are interested in how iron is loaded and stored in mammalian ferritin. Ferrous iron must be oxidized to ferric iron in order to be stored in ferritin. It is generally believed that ferritin does the loading itself, dependant upon a "ferroxidase activity." Oxidation of iron can result in the production of the hydroxyl radical which can cause oxidative damage to surrounding proteins and other biomolecules. An indicator of oxidative damage to proteins is the formation of carbonyl groups. Using only the H subunit of human …

Synthetic Approach To Hexaoxa[6]Peristylanes. A Novel Ddq-Induced Oxidative Rearrangement, Douglas Arthur Otte

Honors Theses

The structural beauty and interesting bonding properties of polycyclic cage compounds have been a source of fascination to many chemists. In this work, progress toward the synthesis of large oxabowl systems, such as hexaoxa[6]peristylane and its derivative dipbenylhexaoxa[6)peristylane, is described. Thus, the adduct obtained from the cycloaddition of maleic anhydride and cyc!ooctatetraene is converted into key dicarbonyl intermediates. Subsequently, the ozonolysis of these intermediates is carried out in order to generate hexaoxa(6)peristylane as well as diphenylhexaoxa[6]peristylane. Molecular modeling studies, performed at the semi-empirical level, are also described.

The Determination Of The Crystal Structure Of 2-Methyl-2methylacrylyl-Cyclohexanone- (1,5)-Diaxaspiro Mononeopentyl By X-Ray Christallography, Joann Stevenson

McCabe Thesis Collection

Cyclohexanone, the central component of the compound 2-methyl-2-methylacrylylcyclohexanone-( l,5)-diaxaspiro mononeopentyl (see figure on page 2), serves as a solvent for oil in piston type aircraft and in natural and vinyl resins. It is used in the production of crude rubber, waxes, fats, shellac and DDT and other pesticides. Cyclohexanone also is a part of the production of adipic acid, which is used to prepare nylon and is used to prepare cyclohexanone resins via condensation to enhance the adhesive properties of products like floor paints.

Cyclohexanones are among the most accessible hydroaromatic derivatives and serve as the initial materials for the …

A Diffuse Reflectance Infrared Fourier Transform Spectroscopic Investigation Of The Oxidation Of Co On Platinum/Tin(Iv) Oxide-Based Catalysts, Julie Christi Stiltner Patrick

Chemistry & Biochemistry Theses & Dissertations

Platinum/tin(IV) oxide-based catalysts have been developed for the oxidation of carbon monoxide at 55 °C and 1 atmosphere pressure. A diffuse reflectance infrared fourier transform spectroscopic (DRIFTS) investigation of this oxidation has been performed. Four catalyst samples have been subjected to a 5% carbon monoxide pretreatment at 125 °C, helium exposure at 55 °C, bottled air (20% oxygen) exposure at 55 °c, and exposure to a 2:1 stoichiometric mixture of carbon monoxide and oxygen at 55 °C. During the course of these exposures, evidence for the development of two different surface carbon monoxide configurations has been found: one that is …

Oxidation Of N,N-Dimethylformamide And N,N-Dimethylacetamide In A Photoreactor, Su-Jen Syu

Theses

Oxidation of N,N-dimethylformamide(DMF) and N,N-dimethylacetamide(DMA) was investigated in a 30 liter semi-batch reactor. Five reaction processes were studied by using UV alone, O₃ alone, O₂/UV, O₂/O₃/UV and H2 O₂/UV respectively. Mathematical models have been developed to interpret the reaction kinetics. Reaction rate constants and mass transfer coefficients were determined by using Rosenbrock Hillclimb optimization algorithm. The experimental data and the predicted results from the models were compared. The kinetic parameters obtained from the previous semi-batch modes were applied to the continuous stirred tank reactor (CSTR) system. Results of this work show …

Surface Area Of Coal As Influenced By Low Temperature Oxidation Processes, Salvador Leon Arredondo

Dissertations and Theses

The possibility of increasing the amount of readily accessible surface area by enlarging the 5 A pore was examined via pretreating the PSOC-371 coal with gases such as nitrogen, nitrogen-oxygen, and ozone-oxygen and hydrogen peroxide solutions. Surface areas were obtained from nitrogen adsorption at 77 K and carbon dioxide adsorption at either 298 or 195 K for each sample before and after treatment.

The Vapor Phase Oxidation Of 1, 3-Pentadiene, David E. Sasser

Retrospective Theses and Dissertations

The vapor phase oxidation of 1.3-pentadiene, over heterogeneous catalysts, was investigated with the objective of producing 2,4-pentadienal and 2,4-pentadienoic acid. Copper and cobalt-molybdenum catalysts, both supported and unsupported, were utilized at various reaction temperatures, residence times and feed ratios. The matter of 1,3-pentadiene vaporization and introduction into the reactor system proved to be critical. Low temperature vaporization of the hydrocarbon and dilution with the oxidant, air, was found to be necessary to avoid polymerization of the feed. Alumina-supported catalysts were found to be very active, leading to severe cracking of the hydrocarbon feed and subsequent carbonization of the catalysts. Silica-supported …

The Liquid Phase Oxidation Of 1,3-Pentadiene, Carl B. Reaves

Retrospective Theses and Dissertations

The liquid phase autoxidation of 1,3-pentadiene to 2,4-pentadienoic acid utilizing gaseous oxygen at atmospheric pressure was investigated as a possible route for direct utilization of piperylene obtained during the cracking of naptha to ethylene. Catalyst system consisting of cobalt, manganese, and iron salts promoted by sodium, potassium and hydrogen bromides, were used under a variety of condition of catalyst concentration, temperature, oxygen flow and piperylene purity. Under all conditions studied, a large number of oxidation products were formed. Maximum yields of 2,4-pentadienoic acid were obtained using a cobalt acetate bromide catalyst at 85°C.

Oxidation Of Thin Silver Films By Ozone And Atomic Oxygen, Lawrence R. Thorne

Undergraduate Honors Capstone Projects

Recently, thin silver film detectors have been used to determine atomic oxygen profiles in the 70-100 km region of the upper atmosphere. The detectors' sensitivity to atomic oxygen is the result of the formation of silver oxide(s) which cause their electrical resistance to increase. A common procedure to calibrate and to make these detectors more sensitive is to cycle them through a series of three or more oxidations and reductions. This paper indicates that this cycling makes silver films more sensitive to ozone, causing them to be usable only at heights greater than 38 km. Also reported herein are experimentally …

Estimations Of The Effective Electrolytic Surface Area Of Rough And Porous Silver Electrodes ; Ii. Potentiostatic Oxidation Of Silver In Alkaline Electrolyte, James Glenn Bearss

Theses and Dissertations

This dissertation is written in two sections. The first section deals with the development of methods for the estimation of the effective electrolytic surface area of rough and porous silver electrodes in alkaline electrolyte. Data are presented comparing the results of three different methods of surface area estimation. Model pore electrodes were also prepared and oxidized to study the reactions in a pore. Data for constant current oxidations of these electrodes is given. The second section deals with the potentiostatic oxidations of silver in alkaline electrolyte. Data are presented on the total charge acceptance versus applied potential for a potential …

The Influence Of Temperature And Some Other Factors On The Biological And Nonbiological Oxidation Of Chalcopyrite, Pyrite And Copper Sulfide, Ezra Revier Palmer

Theses and Dissertations

The purpose of this study was: (1) to find the effect of temperature on the wet oxidation of chalcopyrite, pyrite, and copper sulfide over the biological and nonbiological range; (2) to determine the influence of ferrous and ferric iron and free oxygen(air) on the oxidation. The sulfide minerals studied were oxidized over a range of temperatures between 25° to 75° C. The optimum biological oxidation occurred near 35° C. The nonbiological oxidation was very slow at low temperatures but increased with increasing temperature. The effect of solutions used in leaching the various sulfides over the temperature range differred. A synthetic …

Stability And Concentration Effects In The Use Of Siloxene As A Chemiluminescent Indicator In Redox Titrations, William F. Burkhardt

Chemistry Honors Papers

This 22 page thesis attempts to determine the limitations of, and to extend the applicability of siloxene as a chemiluminescent indicator in redox titrations.

Separation And Identification Of The 2,4-Dinitrophenylhydrazones Of The Oxidation Products Of Glycerol., Gwendolyn Parker Mcclure

Electronic Theses and Dissertations

No abstract provided.

A Study Of Chrome Dyeing By Determination Of Chromium On Dyed Wool And In Exhausted Dye Baths, Thomas Schonfeld

Chemistry Honors Papers

This 13 page thesis attempts to analyze the reaction between the wool and the chromate in the dye bath.

Iron And Cobalt Salts As Catalysts In The Oxidation Of Sodium Sulfite By Free Oxygen, Loren C. Bryner

Theses and Dissertations

The present investigation was carried out to show the catalytic effect of some iron and cobalt salts on the oxidation of sodium sulfite solutions by free oxygen. The rate of reaction was determined by measuring the volume of water required to replace the absorbed oxygen. A photograph and diagrammatical arrangement of the apparatus is given, (Page 14). From the preliminary experiments it was found that the rate of oxidation of sodium sulfite solutions is dependent upon concentration, and speed of the shaker.

Volumetric Chemical Analysis, Beatrice Brooks

Chemistry Honors Papers

This 20 page thesis illustrates various methods of volumetric processes.