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Articles 1 - 16 of 16
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Study On Methods Of Simultaneous Multi-Component Analysis., Jennifer Bernice Ashie
Study On Methods Of Simultaneous Multi-Component Analysis., Jennifer Bernice Ashie
Electronic Theses and Dissertations
Many new instrumentation and different instrumental techniques have been developed to deal with increasing complexity of samples encountered. Many researchers also have coupled these instrumental techniques with chemometric algorithms to assist in the quantitative analysis of multi-component samples in the hope of alleviating the need of tedious separation and cleanup procedures. These newer chemometric procedures tend to be complex and difficult to understand and implement and are successful under different circumstances and conditions. In this study, we start from the very simple beginning and examine the factors that can present difficulties with obtaining the correct results and observe how the …
Studies Of Surfactants Effect On Riboflavin Fluorescence And Its Determination In Commercial Food Products And Vitamin Tablets., William Emmanuel Ghann
Studies Of Surfactants Effect On Riboflavin Fluorescence And Its Determination In Commercial Food Products And Vitamin Tablets., William Emmanuel Ghann
Electronic Theses and Dissertations
A simple and economical fluorometer using blue LEDs excitation sources and simple PMT detection had been built, assembled, optimized, and employed for measurement of fluorescence from riboflavin (vitamin B2). Surfactants have been known to enhance the intensity of fluorescence of fluorescent compounds. Fluorescence analysis of riboflavin in the presence of various anionic, cationic, and nonionic surfactants was also conducted to determine if they could improve analysis. However, the surfactants employed did not seem to have any meaningful enhancement; in fact, some actually diminished the fluorescence intensity of riboflavin. The procedure was linear for riboflavin from 0.01 to 2.5 …
Towards The Design And Syntheses Of Novel Triads Comprising Single Robson-Type Macrocyclic Dicopper(Ii) Cores Flanked By Two Terminal Polypyridyl Ruthenium(Ii) Complexes., Leslie Shane Moody
Towards The Design And Syntheses Of Novel Triads Comprising Single Robson-Type Macrocyclic Dicopper(Ii) Cores Flanked By Two Terminal Polypyridyl Ruthenium(Ii) Complexes., Leslie Shane Moody
Electronic Theses and Dissertations
Progress toward the syntheses of new tetranuclear bimetallic complexes of copper(II) and ruthenium(II) was realized. The designed triads comprise a central binuclear copper(II) complex with a tetraiminodiphenolate macrocyclic Robson-type compartmental ligand. In the envisioned complexes, the macrocyclic core is further functionalized by attachment of two polypyridyl ruthenium(II) complexes. A novel dibrominated dicopper(II) Robson complex was formed by the 2:2:2 condensation reaction of 4-bromo-2,6-diformylphenol and 1,3- diaminopropane with cupric chloride. Similarly, a new dibrominated dizinc(II) was synthesized from zinc tetrafluoroborate and the same diamine and dialdehyde. The new dicopper(II) complex did not heterocouple with borylated substrates under explored Suzuki reaction conditions. …
Synthesis Towards Fulminic Acid And Its Derivatives In 1, 3-Dipolar Cycloaddition Reactions., Ophilia Ndi Toh
Synthesis Towards Fulminic Acid And Its Derivatives In 1, 3-Dipolar Cycloaddition Reactions., Ophilia Ndi Toh
Electronic Theses and Dissertations
A new approach to fulminic acid cycloadditions has been developed. At reduced temperatures, fulminic acid is generated in situ and undergoes 1, 3-diploar cycloaddition reactions with dipolarophiles to form isoxazolines and/or its dimers. This procedure represents a novel, safe general method for the one-step generation of fulminic acid, which complements existing potentially explosive protocols.
Monitoring Metal Containing Particulates Distribution On A College Campus Using Dandelion (Taraxacum Officinale) Leaves As Receptors., Suresh Chandra Regmi
Monitoring Metal Containing Particulates Distribution On A College Campus Using Dandelion (Taraxacum Officinale) Leaves As Receptors., Suresh Chandra Regmi
Electronic Theses and Dissertations
This study aims to determine the distribution of particulates carrying heavy metals at selected sites on a college campus using dandelion leaves as collectors. As a comparison, sites far away from the campus surrounding Bristol Motor Speedway Car Racing Stadium were also monitored. To reduce the probability of memory effects from the long-term atmospheric deposition or absorption of metals from soil a seasonal plant, dandelion, was used to monitor the metal contents. The metals monitored are cadmium, calcium, copper, chromium, iron, lead, and zinc. Fourteen sites were monitored and samples were collected once a week initially (growing time of the …
Contraction-Expansion Protocols., Nadine Katia Njoya
Contraction-Expansion Protocols., Nadine Katia Njoya
Electronic Theses and Dissertations
An approach to a new class of compounds known as bridgehead dienone is described. The route is based on a tandem contraction-expansion event in which the contraction triggers the expansion. The two steps involved are a palladium-catalyzed Favorskii contraction and a cis-divinyl cyclopropanone rearrangement. Progress towards these goals is reported.
Synthesis And Oxidation Of Lignin-Carbohydrate Model Compounds, Mai Thanh Thi Nguyen
Synthesis And Oxidation Of Lignin-Carbohydrate Model Compounds, Mai Thanh Thi Nguyen
Electronic Theses and Dissertations
To decrease our dependence on foreign oil supply and in an effort to decrease the amount of green house gases into the atmosphere, researchers are focusing on ways of producing fuels and chemicals from renewable resources. A renewable source such as wood has great potential for the production of biofuels and biochemicals. An integrated biorefinery process that maximizes the usage of wood and complements existing pulp and paper technology was proposed to extract underutilize hemicelluloses and covert them into bioethanol. In this process, not only hemicelluloses are extracted; lignin, since it is covalently bonded to hemicelluloses is extracted as well. …
Characterization Of Commercial Pectin Preparations By Spectroscopic And Chromatographic Techniques., Daniel Wayne Dixon
Characterization Of Commercial Pectin Preparations By Spectroscopic And Chromatographic Techniques., Daniel Wayne Dixon
Electronic Theses and Dissertations
Pectin has a long history as a food additive. However, elucidation of its fine structural and property relationships remains elusive. Recent research has focused on pectin's ability to complex with divalent heavy metals to aid in characterizing it. Commercial pectins of unknown composition were obtained from local grocers. Purified pectin samples from orange peel, lemon peel, and apple pomace, each of low and high levels of methyl esterification and of unknown distribution pattern were also purchased. Instead of metal complexation, several highly absorbing dyes such as Ruthenium Red, Nile Blue, and Acridine Orange were used to complex with the pectins …
Surface Engineering Of Gold Nanoparticles And Their Applications, Qiu Dai
Surface Engineering Of Gold Nanoparticles And Their Applications, Qiu Dai
Electronic Theses and Dissertations
Gold nanoparticles (AuNPs) with their unique sizes, shapes, and properties have generated much enthusiasm over the last two decades, and have been explored for many potential applications. The successful application of AuNPs depends critically on the ability to modify and functionalize their surface to provide stability, compatibility, and special chemical functionality. This dissertation is aimed at exploring the chemical synthesis and surface modification of AuNPs with the effort to (1) control the number of functional groups on the particle surface, and to (2) increase the colloidal stability at the physiological conditions. To control the functionality on the particle surface, a …
Forensic Analysis Of Automobile Paints By Atomic And Molecular Spectroscopic Methods And Statistical Data Analyses, Erin Mcintee
Forensic Analysis Of Automobile Paints By Atomic And Molecular Spectroscopic Methods And Statistical Data Analyses, Erin Mcintee
Electronic Theses and Dissertations
The analysis of 110 automotive paint samples was conducted for the research presented here. Laser-induced breakdown spectroscopy (LIBS) was the central instrument utilized for analysis although scanning electron microscopy / energy dispersive x-ray spectroscopy (SEM/EDS) and Fourier transform infrared spectroscopy - attenuated total reflection (FTIR-ATR) analyses were also performed. Two separate methods of LIBS analysis of samples were used: a cross sectional analysis and a drill down analysis. SEM/EDS analysis focused on the cross section while FTIR-ATR analysis concentrated on the clearcoat layer. Several different data/statistical analyses were evaluated including principal components analysis (PCA), two tailed t-tests based on several …
The Development Of A "Genetic Eyewitness" Profiling System For Low Template Forensic Specimens: Identification Of Novel Protein, Rna, And Dna Biomarkers, Erin Hanson
Electronic Theses and Dissertations
In many criminal investigations, valuable information regarding the physical appearance of suspected perpetrators or the time and order of events that transpired are provided by eyewitness accounts. However, the information obtained from eyewitnesses is often constrained by human recollection or subjective accounts and provides a biased description of the perpetrator's appearance or an inaccurate time line of events. Additionally, in numerous situations eyewitness accounts may not be available. An increasing reliance therefore is placed on the biological evidence recovered during criminal investigations to act as a silent witness, providing unbiased and scientific information that may aid in the resolution of …
The Identification Of Ignitable Liquids In The Presence Of Pyrolysis Products: Generation Of A Pyrolysis Product Database, Joseph Castelbuono
The Identification Of Ignitable Liquids In The Presence Of Pyrolysis Products: Generation Of A Pyrolysis Product Database, Joseph Castelbuono
Electronic Theses and Dissertations
The fire debris analyst is often faced with the complex problem of identifying ignitable liquid residues in the presence of products produced from pyrolysis and incomplete combustion of common building and furnishing materials. The purpose of this research is to investigate a modified destructive distillation methodology provided by the Florida Bureau of Forensic Fire and Explosive Analysis to produce interfering product chromatographic patterns similar to those observed in fire debris case work. The volatile products generated during heating of substrate materials are extracted from the fire debris by passive headspace adsorption and subsequently analyzed by GC-MS. Low density polyethylene (LDPE) …
Determination Of The Degradation Mechanism For Polychlorinated Biphenyl Congeners Using Mechanically Alloyed Magnesium/Palladium, Robert Devor
Electronic Theses and Dissertations
Polychlorinated biphenyls are a ubiquitous environmental contaminant that can be found today throughout the world in soils and sediments, lakes and rivers, and flora and fauna. PCBs have percolated throughout the food chain, so that almost every human being has a detectable amount of the contaminant within their blood stream. Existing remediation methods include incineration, dredging and landfilling, and microbial degradation, but all of these methods have drawbacks that limit their effectiveness as treatment options. Recently, the use of zero-valent metals as a means of reductive dechlorination has been explored. Using a combination of zero-valent magnesium and catalytic palladium, a …
Solution Processible Aromatic Polyimides Via Diels Alder Precursor, Saral Shah
Solution Processible Aromatic Polyimides Via Diels Alder Precursor, Saral Shah
Electronic Theses and Dissertations
Aromatic polyimides are interesting materials since they possess outstanding key properties such as thermoxidative stability, high mechanical strength, high modulus, excellent electrical properties, and superior chemical resistance. However, their low solubility makes them difficult to characterize, process and obtain high molecular weight polymer. In this report, we synthesized a series of precursor polymers that contains Diels-Alder (DA) adducts of anthracene. Different dienophiles were tried. These precursor polymers are soluble in common organic solvents such as chloroform and can be easily processed to thin films. Heating the film above 215 degree induce retro-DA reaction, which generated the fully aromatic polyimides in …
Chromatographic And Mass Spectral Analyses Of Oligosaccharides And Indigo Dye Extracted From Cotton Textiles With Manova And Ano, Jessica Frisch
Chromatographic And Mass Spectral Analyses Of Oligosaccharides And Indigo Dye Extracted From Cotton Textiles With Manova And Ano, Jessica Frisch
Electronic Theses and Dissertations
Research was conducted on thirteen 100% cotton denim samples using an acid wash, established by Murray, to extract oligosaccharides from the cellulosic material. The oligosaccharide ion groups (+, +, and +) for molecules with degrees of polymerization between two and seven (DP2-DP7) were analyzed using liquid chromatography coupled to mass spectrometry with an electrospray ionization interface (LC-ESI-MS). The results were compared using the least-squares means in a Multivariate ANOVA (MANOVA) test followed by Univariate ANOVA and Tukey HSD tests and demonstrated that the method could correctly determine that two samples were statistically different 85.9% of the time when analyzing the …
Development And Forensic Application Of Dye Probe Fluorescence Resonance Energy Transfer For Improved Detection Of Changes In Dn, Micah Halpern
Development And Forensic Application Of Dye Probe Fluorescence Resonance Energy Transfer For Improved Detection Of Changes In Dn, Micah Halpern
Electronic Theses and Dissertations
Discovering, screening, and associating changes in DNA sequence are important to a broad range of disciplines and play a central role in Forensic Science. The typical types of changes include sequence variations [single nucleotide polymorphisms (SNP)] and length variations [short tandem repeats (STR)]. The steps for forensic DNA sample processing are similar for both types of changes but diverge at the point of detection. A number of approaches are being explored for SNP genotyping while STR analysis primarily consists of size-based analysis by capillary electrophoresis. Limitations exist for all current detection methods that pose significant impacts to forensic analysis. Bi-allelic …