Thesis (M.S.)--University of Missouri, School of Mines and Metallurgy, 1921. / The entire thesis text is included in file. Typescript. Illustrated by author. Title from title screen of thesis/dissertation PDF file (viewed June 3, 2009) Includes bibliographical references (p. 21-23).

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In this work the method of isotopic substitution in neutron diffraction is used to measure the partial structure factors of several binary systems. Molten sodium chloride at 820(5) °C is investigated and an improvement is made on the previously available data. The applicability of a simple model pair potential for the asymptotic decay of the pair correlation functions is discussed. The glass forming system zinc chloride is also investigated in both the molten phase at 332(5) °C and the glassy phase at 25(1) °C. The measured partial pair distribution functions show that the zinc atoms are fourfold coordinated in both the glass and the liquid and that the first sharp diffraction peak in the total structure factor is mainly due to the zinc-zinc correlations. A simple ionic model can account for several factors associated with the ultimate decay of the partial pair correlation functions.

Thesis (Ph. D.)--Institute of Paper Chemistry, 1969. / Includes bibliographical references (p. 49-51).

Thesis (Ph. D.)--Institute of Paper Chemistry, 1962. / Includes bibliographical references (p. 44).

Desde sua descoberta em meados do século XIX, os reagentes organometálicos têm sido amplamente utilizados na síntese orgânica, sendo bastante eficientes na formação de novas ligações carbono-carbono. A escolha do reagente organometálico ideal para determinada reação envolve conhecimentos relacionados à sua natureza química e à própria reatividade do substrato. O núcleo quinoxalínico apresenta um grande potencial para a química medicinal, estando presente em diversos produtos naturais e sintéticos que apresentam atividade biológica. Apesar disso, existem poucos estudos na literatura sobre a aplicação de reagentes organometálicos na funcionalização de quinoxalinas. A reação de metalação dirigida usando bases organometálicas é uma poderosa ferramenta para funcionalização de substratos aromáticos. Contudo, exemplos da aplicação desta estratégia na funcionalização de quinoxalinas são bastante raros. Assim, este trabalho teve como principal objetivo investigar a reatividade dos reagentes organometálicos derivados de zinco, magnésio e lítio em reações de metalação de quinoxalinas substituídas com grupos funcionais nas posições C-2 e C-6. Embora as quinoxalinas substituídas com grupos éster, amida e fenil na posição C-2 não tenham apresentado a reatividade esperada frente aos amidetos mistos de zinco e magnésio (TMPZnCl?MgCl2?LiCl, TMP2Zn?2MgCl2?2LiCl, TMPMgCl?LiCl e TMP2Mg?2LiCl), uma nova metodologia foi desenvolvida utilizando TMPLi como base, na presença de ZnCl2, que permitiu a preparação de vários derivados difuncionalizados em bons rendimentos, muitos dos quais de estrutura inédita. Quinoxalinas não substituídas nas posições C-2 e C-3 possuem reconhecida intolerância à presença de reagentes organometálicos, rendendo preferencialmente produtos de dimerização. Desta forma, uma contribuição importante deste trabalho foi o desenvolvimento de uma metodologia de funcionalização da quinoxalina de estrutura mais simples em micro-ondas, mediada pelo sistema TMPMgCl?LiCl/ZnCl2, que permitiu a preparação de diversos derivados arilados em rendimentos que variaram de razoáveis a bons (25 a 94%). Além disso, a metodologia mostrou-se bastante eficiente para síntese de ligantes bidentados de interesse para a área de catálise / Since its discovery in the mid-nineteenth century, organometallic reagents have been widely used in organic synthesis, being very effective in the formation of new carbon-carbon bonds. The choice of the ideal organometallic reagent for certain reaction involves knowledge related to their chemical nature and reactivity of the substrate itself. The quinoxaline core has great potential for medicinal chemistry and is present in many natural and synthetic products presenting biological activity. Nevertheless, there are few studies on the application of organometallic reagents in the functionalization of quinoxalines. The directed metalation reaction using metal bases is powerful synthetic tool for functionalization of aromatic substrates. However, examples on the application of such strategy to the functionalization of of quinoxalines are very rare. This work mainly aimed to investigate the reactivity of organometallic reagents of zinc, magnesium and lithium in the metalation of quinoxalines substituted with functional groups at the C-2 and C-6 positions. Although C-2 substituted quinoxalines with ester and amide groups have not shown the expected reactivity with mixed amides of zinc, magnesium and lithium (TMPZnCl?MgCl2?LiCl, TMP2Zn?2MgCl2?2LiCl, TMPMgCl?LiCl and TMP2Mg?2LiCl), a new methodology was developed using TMPLi as a base in the presence of ZnCl2, allowing the preparation of various difuncionalized derivatives in good yields, many of them new compounds. Quinoxalines unsubstituted at the C-2 and C-3 positions have recognized intolerance to the presence of organometallic reagents, preferably yielding dimerization products. Thus, an important contribution of this work was the development of a functionalization methodology of the simplest quinoxaline in microwave mediated by the TMPMgCl?LiCl/ZnCl2, allowing the preparation of various arylated derivatives in yields ranging from reasonable to good (25 to 94%). Furthermore, the methodology could be applied to the synthesis of bidentate ligands of interest for catalysis

This study aimed synthesizing hydroxylapatite (HA) and Zn2+, F- and Cl- doped HA by solution precipitation method. The synthesized compounds were sintered at 1100&deg / C for 1h. For structural characterization, density of the samples were measured by Archimedes&rsquo / method. It was observed that Zn2+ addition increased the density significantly whereas F- caused a decrease and Cl- increased the density with a little amount. XRD was applied to the samples and it was found that co-doping of Zn2+ and F- ions decreased the unit cell volume of HA with F- addition. Other compositions gave fluctuated results in terms of unit cell volumes. HA phase and a little amount of CaO phase were detected in some samples. FTIR spectroscopy was used to detect whether Zn2+, F- and Cl- ions were incorporated to the HA structure or not by observing the bands corresponding to the bonds in the molecules. The amount of addition was also detected by FTIR. Results showed that ion incorporation to the HA structure was done successfully. SEM images were v analyzed and grain sizes of samples were calculated by Rietvelt analysis. Grain sizes of the samples increased by Cl- addition and decreased by Zn2+ and/or F- addition. For mechanical characterization, Vickers microhardness test was applied. Fracture toughness was calculated from Vickers microhardness results. According to the results, the highest microhardness values were found for F- and Zn2+ co-doped samples. It was also shown that fracture toughness decreased by Zn2+ addition. However, Zn2+ and F- co-doped samples gave higher fracture toughness results when compared with pure HA. Cl- addition also decreased the fracture toughness. The best compositions in terms of structural and mechanical properties was chosen as Zn2+ and F- co-doped samples and biological characterization was applied to these samples. Saos-2 cell line was used in biological examinations. For biological characterizations, Alamar Blue&trade / assay to detect viability and alkaline phosphatase activity (ALP) assay to detect differentiation were done. It was observed that 2 mol.% Zn2+ addition increased the cell viability and alkaline phosphatase activity. 1 mol.% F- addition also improved cell viability and alkaline phosphatase activiy. SEM images were analyzed to observe the morphology of the cells on HA and selected doped HA discs. In accordance with Alamar Blue&trade / assay and alkaline phosphatase activity assay, cells showed dendritic shapes on 2 Zn and 2 Zn 1 F sample which was the indicator of good material-cell interaction. Dissolution test was also applied by immersing the samples in simulated body fluid (SBF). pH change and SEM images for Ca2+ deposition were investigated. Increase in pH change with time was observed. F- included samples gave the lowest pH change results, especially 2 Zn 1 F. Dissolution pits and some apatitic formations were observed in SEM images.

Thesis (M.S.)--Mississippi State University. Department of Plant and Soil Sciences. / Title from title screen. Includes bibliographical references.