Thesis (M.S.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains xiv, 137 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 106-109).

Thesis (MTech. degree in Chemistry)--Tshwane University of Technology, 2008. / This work is aimed at experimental verification of the theory about the advantages of the two-step sample vapour release in a fast-heated ballast furnace. The term “ballast” was introduced earlier in electrothermal atomic absorption spectrometry, as an alternative to a platform to describe a compact body of refractive material loosely located on the bottom of a tube furnace atomiser. The thermal behaviour of the ballast furnace is similar to that of the platform, but without restriction created by the platform area. Compared with the flat or concave platform, a compact ballast of similar mass to the platform should have less impact on gas temperature because of the smaller surface area. The theoretical predictions concerning atomisation efficiency in the fast-heated ballast furnace were examined by the determination of metals in organic and inorganic matrices using a Quantum Z.ETA atomic absorption spectrometer. The instrument provided fast heating of the tube atomizer, 10 K ms-1. It is shown that in the employed ballast furnace the vapour released into the gas phase occurs after interim condensation on the ballast. For the samples of tetraethyllead, base oil and aqueous solutions of various metals, analytical signals are observed after stabilisation of tube temperature, independent of volatility of the analyte and level of temperature setting. For those samples, a high gas phase temperature provides complete recovery of the analyte without involvement of chemical modifiers and the reduction of spectral interferences from chloride matrices.

Seven iron ore pellets, two sinters, and one lump ore were studied in CO-CO₂-H₂-N₂ atmospheres from 350°C to 750°C, simulating the upper stack of the ironmaking blast furnace. Experiments were performed in a flowing gas reactor on single specimens of each type of substrate. Two different measurements were made: (1) the carbon deposition and concurrent iron oxide reduction rate at 550°C in 30%CO, 10%CO₂, 2%H₂, and 58%N₂; and (2) the amount of carbon deposited during a programmed increase in temperature and change in CO-CO₂ ratio simulating the descent of an ore specimen in the blast furnace stack. The rates of the concurrent reaction were determined from mass balances based on gas chromatographic analyses of the CO, CO₂H₂, and N₂ in both the inlet and outlet gases and the continuously recorded mass of the specimen. The materials were examined as to chemical composition, internal structure, porosity, and surface area. Elemental analyses of single iron oxide grains were made by electron microprobe. Slag materials and composition, and crystallinity were determined by microprobe and X-ray diffraction. The results of the experiments show that carbon deposition occurs only in the presence of metallic iron which is produced from the concurrent reduction of Fe₃O₄. The degree of reduction is controlled largely by the structure of the substrate, but the carbon deposition is controlled only by the chemical composition of the substrate--specifically, silicon in the iron and the CaO to MgO ratio. In the blast furnace simulation, the carbon deposition increases for pellets fluxed with dolomite to a maximum with lime-fluxed pellets. The effects of H₂ and CO₂ on the reactions were investigated in the isothermal experiments using an Empire pellet. The CO₂ controlled only the reduction, and this by diffusion of the CO₂. The hydrogen in very small amounts enhanced the deposition of carbon, probably by eliminating the presence of the inactive iron carbides. Under blast furnace conditions, the changes in the operation when the chemistry of the ore feed is changed to fluxed pellets will be due more to the shifts in the available heat within the stack from carbon deposition than to the low temperature reduction of the ores, which does not change with the addition of the flux materials.

Šio tyrimo objektas – Lietuvos muziejų erdvėse eksponuojamų koklinių krosnių rekonstrukcijos įvertinimas autentiškumo ir paveldosauginiu aspektu. Pagrindinis darbo tikslas – išanalizuoti ir įvertinti Lietuvos muziejų erdvėse eksponuojamų krosnių rekonstrukcijas. Darbe gilinamasi į atkūrimo autentiškumo problematiką. Vieni iš svarbiausių tikslui pasiekti keliamų uždavinių yra koklinių krosnių rekonstrukcijų reikšmės analizė bei būdingųjų verčių nustatymas. Kadangi koklinių krosnių rekonstrukcijos Vilniaus Žemutinėje pilyje yra ne tik didžiausios savo mastu, bet ir sudėtingiausios, didžiausias dėmesys tyrime skiriamas būtent šiam muziejui. Darbe atliekama mokslinių tyrimų duomenų, koklinių krosnių rekonstrukcinių maketų analizė, nagrinėjami teoriniai bei teisiniai pagrindai, kuriais remiamasi rekonstruojant Vilniaus Žemutinės pilies koklines krosnis, analizuojamos bei vertinamos koklinių krosnių eksponavimo vieta bei galimybės. Vertinimo kriterijais pasirinkus paveldosauginius, meninius, autentiškumo kriterijus, atliekamas koklinių krosnių rekonstrukcijų įvertinimas. Tyrimas reikšmingas tuo, kad atkreips dėmesį į Lietuvoje rekonstruojamas koklines krosnis. Aktualus paliestu autentiškumo ir moksliškumo klausimu. Šis darbas gali būti naudingas paveldo apsaugos specialistams, susiduriantiems su archeologiniu, architektūriniu paveldu, menotyrininkams bei muziejininkams. / The subject of this research is reconstructed tile furnaces exposed in spaces of Lithuanian museums. The aim of this work is to analyze and evaluate those reconstructions using the test of authenticy and main principles of conservation. Talking about reconstruction itself, the main problem of authenticy occurs. One of the main purpose in this work is the analysis of importance of reconstructed tile furnaces and attempt to select the typical values they implicate. As the reconstruction of tile furnaces in Lower castle of Vilnius is of the largest extent and also the most complicate one, the greatest attention in this work is dedicated to this museum. Amongst the main difficulties of reconstruction are: colleting tiles and making reconstructions, localization of original places of tile furnaces, attribution problem dealing with remains of tiles from various furnaces. The methods used in this work are: analysis of scientific information and models of reconstruction of tile furnaces, also the theoretical and juridical aspects are analyzed on which the idea of reconstruction is based. Also in the research is given the evaluation of the place of exhibition and stressed possibilities. To pursue the evaluation, various criteria have been chosen: the reconstructions of tile furnaces are analyzed according to principles of conservation, art and authenticy. This research is important because it spotlights the problem of reconstruction of tile furnaces, and relevant because of its... [to full text]

No description available.

No description available.

Thesis (Ph.D.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on March 19, 2009) Vita. Includes bibliographical references.

Thesis (Ph. D.)--Missouri University of Science and Technology, 2009. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed February 18, 2009) Includes bibliographical references.

Thesis (MSc.(Metallurgical Engineering)--University of Pretoria, 2007. / Includes bibliographical references.

Memoire (M.Sc.A.)--Universite du Quebec a Chicoutimi. 1987. / Bibliogr.: ff. 161-175. Document électronique également accessible en format PDF. CaQCU