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<p> A series of shallow intrusive and extrusive silicic volcanic rocks near Mamainse Point, Ontario, were sampled and analyzed for major and trace elements. The rocks are mainly fine grained, silicified rhyolites grading to dacites containing phenocrysts of quartz and feldspar. The analyses performed (XRF, AAS) indicate that many of these rocks have been altered from the normal igneous spectrum of rocks to potassic keratophyres. An enrichment in potash from potash metasomatism has accompanied low grade, burial metamorphism to produce a secondary mineral assemblage including chlorite, carbonate, and sericite. Local intense alteration of some rocks involved the depletion of mobile alkalis and addition of water and co2 to form calcite and kaolin. The overall field and chemical evidence suggest a single magmatic source for these rocks. </p> / Thesis / Bachelor of Arts (BA)

A safe storage of radioactive waste in repositories is an important task to protect humans and the environment from radio- and chemotoxicity. Long-term safety assessments predict the behavior of potential environmental contaminants like the actinides plutonium, uranium, or neptunium, in the near and far field of repositories. For such safety assessments, it is necessary to know the migration behavior of the contaminants in the environment, which is mainly dependent on the aquatic speciation, the solubility product of relevant solid phases, and the retardation due to sorption on surrounding minerals. Thus, an investigation of sorption processes of contaminants onto different minerals as well as the derivation of mineral specific surface complexation model (SCM) parameters is of great importance. Feldspar and mica are widely distributed in nature. They occur as components of granite, which is considered as a potential host rock for a repository in Germany, and in numerous other rocks, and thus also in the far field of nearly all repositories. However, their sorption behavior with actinides has only been scarcely investigated until now. In order to better characterize these systems and subsequently to integrate these minerals into the long-term safety assessments, this work focuses on the investigation of the sorption behavior of U(VI), Np(V), and Nd(III) as analogue for An(III) onto the minerals orthoclase and muscovite, representing feldspars and mica, respectively. All investigations were performed under conditions relevant to the far field of a repository. In addition to the extensive characterization of the minerals, batch sorption experiments, spectroscopic investigations, and surface complexation modeling were performed to elucidate the uptake and speciation of actinides on the mineral surfaces. In addition, the influence of microorganisms naturally occurring on the mineral surfaces and the effect of Ca2+ on U(VI) uptake on the minerals was studied. The obtained sorption curves exhibit a similar characteristic for orthoclase and muscovite. As expected Nd(III) shows the highest amount of sorption followed by U(VI) and finally Np(V). With spectroscopic investigations of the aquatic U(VI) solution in presence of Ca2+, the Ca2UO2(CO3)3 complex could be identified. Furthermore, with spectroscopic methods the U(VI) surface species onto orthoclase could be characterized, of which a novel uranium-carbonate surface species was observed. Based on the results of batch experiments and spectroscopic methods new SCM parameters for the sorption of U(VI), Np(V), and Nd(III) onto orthoclase and for Np(V) and Nd(III) onto muscovite could be derived. SCM parameters for U(VI) sorption onto muscovite confirmed earlier investigations. The obtained SCM parameters increase the amount of data available for sorption processes onto feldspar and mica. With this the relevance of feldspars for the sorption of actinides and lanthanides could be shown. Thus, this work contributes to a better understanding of interactions of actinides and lanthanides, in particular U(VI), Np(V), and Nd(III), with mineral phases ubiquitous in the environment. This in turn adds confidence to long-term safety assessments essential for the protection of humans and the environment from the hazards of radioactive waste.

This thesis investigates pricing to market behavior in the exports of Turkey, which is a small economy. The investigated sectors are hazelnut, dried grape, dried apricot, dried fig and feldspar. The sectors are selected because Turkey is the leading producer and exporter for these products in the world. We apply pricing to market model for the exports from Turkey to each of the largest importer countries and the world in total for each product to check whether there is monopolistic behavior in the markets. We also check whether there is complete local currency price stability in the investigated markets. The relationship between the import shares of destination markets in the Turkey&amp / #8217 / s exports and the estimated pricing to market elasticities are compared as well. In general, we find that there is pricing to market in the exports of Turkey for the investigated sectors.

Made available in DSpace on 2015-04-01T12:17:42Z (GMT). No. of bitstreams: 1 Aquivototal.pdf: 4458207 bytes, checksum: c998f318cd914a74966cc43b803e4c8d (MD5) Previous issue date: 2014-02-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / It is estimated that there are 500,000 acres of mesquite (Prosopis juliflora) planted in the Brazilian Northeast, 45% only on State of Paraíba. In State, the wood is used almost exclusively as fuel on drying kilns and firing of ceramic products in brick kilns, generating ash as residue. These ashes contain a high concentration of alkaline metals and earth metals, mainly CaO and K2O. This work studies the use of this residue in the ceramic tiles industry, in substitution to the feldspar. Thirteen mixtures with equal ratios of clay, kaolin and quartz, and the residue (varying from 5% to 20%, still under three granulometric perspectives), and prepared specimens of dimensions 110 mm x 55 mm x 8 mm in uniaxial tool die, with compacting pressure of 15 MPa. The samples were fired in three different temperatures: 1160°C, 1190°C and 1220°C, during 20 minutes, and characterized by means of X-ray fluorescence, X-ray diffraction, gravimetric thermal analysis and differential thermal analysis. The results of water absorption, apparent porosity and specific mass, linear shrinkage and flexural strength were also analysed. The specimens with addition of 5 and 10% ash, of granulometric -#35 +#60 (250 μm < particle size < 500 μm), fired in 1220°C, presented results of water absorption of 0.99% and 0.62%, respectively, which according to the ABNT, ASTM and ISO standards can be classified as stoneware tiles, and flexural strength of 23.3 and 23.0 MPa, respectively, being classified as coating materials. / Estima-se que existam 500 mil hectares de algarobeiras (Prosopis juliflora) plantadas no Nordeste, 45% do montante só na Paraíba. No Estado, a lenha é utilizada quase que exclusivamente como combustível nos fornos de secagem e queima de produtos cerâmicos nas olarias, gerando uma cinza como resíduo/subproduto. As cinzas da lenha de algaroba apresentam elevadas concentrações de metais alcalinos e alcalinos-terrosos, principalmente CaO e K2O. O presente trabalho estuda a utilização desse resíduo na indústria de placas cerâmicas para revestimentos, em substituição ao feldspato. Foram definidas 13 formulações com iguais proporções de argila, caulim e quartzo, e o resíduo (variando de 5 a 20%, ainda sob três perspectivas granulométricas), e confeccionados corpos de prova de dimensões 110 mm x 55 mm x 8 mm em matriz uniaxial, com pressão de compactação de 15 MPa. As amostras foram sinterizadas em três níveis de temperatura, 1160°C, 1190°C e 1220°C, com patamar de queima de 20 minutos. Foram realizados ensaios para caracterização das matérias-primas por fluorescência de raios-X, difração de raios-X, AG, DTA e ATG, e analisados os resultados de absorção de água, porosidade e massa específica aparentes, retração linear e tensão de ruptura à flexão. Os corpos de prova com adição de 5 e 10% de cinzas, de granulometria -#35 +#60 (250 μm < tamanho de partícula < 500 μm), sinterizados a 1220°C, apresentaram resultados de absorção de água de 0,99% e 0,62%, respectivamente, o que segundo as normas ABNT, ASTM e ISO podem ser classificados como grês porcelanato, e resistência à flexão de 23,3 e 23,0 MPa, respectivamente, caracterizando-os como materiais de revestimento.

Made available in DSpace on 2014-12-17T14:57:55Z (GMT). No. of bitstreams: 1 RaimundoJSP.pdf: 1219471 bytes, checksum: d712293aa14f71b340c5cbfd7467bfe4 (MD5) Previous issue date: 2010-01-12 / This study aimed to investigate the use of cane sugar ashes from small-scale stills of Eun?polis region, state of Bahia, in pottery mass that can be developed as porcelain stoneware. Bahia is the second largest producer of rum distillery in Brazil. In the production of rum is produced residue called bagasse, which is used to generate electricity in Power plants and in the distillery itself, generating ashes as residue, which is played in nature, causing environmental damage. We studied 5 (five) formulations of 0% 10% 20%, 30% and 40% by weight of the ash, without ignition and 3 (three) formulations of 10%, 20% and 30% with gray ash temperature of 1250?C. The formulation at 0% by weight of ash was used for a comparison between the traditional mass of porcelain stoneware and the masses with the addition of ash calcined, replacing feldspar. The percentage by weight of kaolin and of Clay was kept the same, 30%, and all raw materials were derived from the state of Bahia. The samples were made in uniaxial array with dimensions of (60 x 20 x 5) mm and compressed to a pressure of 45 MPa. Assays were performed to characterize the raw by X-ray fluorescence, X-ray diffraction, ATD and ATG and Dilatometric analysis. The samples were sintered at temperatures of 1100?C, 1150?C, 1200?C and 1250?C, for the specimens with the ashes without ash and 1150? C and 1200? C for specimens with the gray level of calcined 60 minutes. and then we made a cooling ramp with the same rate of warming until reach ambient temperature. The sintered bodies were characterized by water absorption, porosity, linear shrinkage, bending strength and XRD of the fracture surface and the results analyzed. It was proven, after results of tests performed, that it is possible to use the ash residue of sugar cane bagasse on ceramic coating with the addition of up to 10% wt of the residue ash / O presente trabalho visa a investigar a utiliza??o da cinza do bala?o da cana de a??car proveniente do alambique artesanal da regi?o de Eunapolis-BA em massa cer?mica que poder? ser aproveitada como um gr?s porcelanato. A Bahia e o segundo estado brasileiro maior produtor de cacha?a de alambique do Brasil. Na produ??o da cacha?a, e produzido res?duo chamado bala?o , sendo este utilizado na gera??o de energia el?trica em usinas termoel?tricas e na pr?pria destilaria, gerando uma cinza como res?duo, que e jogada na natureza, provocando danos ambientais. Foram estudadas 5 (cinco) formula??es de 0% 10%, 20%, 30% e 40% em peso de res?duo de cinza sem calcina??o e 3 (tr?s) formula??es de 10%, 20% e 30% com a cinza calcinada na temperatura de 1250oC. A formula??o em 0% em peso de cinza serviu para uma compara??o entre a massa tradicional do gr?s porcelanato em rela??o as massas com a adi??o de cinza sem calcinar e calcinada, em substitui??o ao feldspato. A percentagem em peso da argila e do caulim foi mantida a mesma, 30%, e todas as mat?rias-primas foram oriundas do estado da Bahia. Os corpos de prova foram confeccionados em matriz uniaxial com as dimens?es de (60 x 20 x 5) mm e compactados a uma press?o de 45 MPa. Foram realizados ensaios para caracteriza??o das mat?rias-primas por fluoresc?ncia de raios X, difra??o de raios X, ATD, ATG, e analise dilatometrica. As amostras foram sinterizadas nas temperaturas de 1100?C, 1150?C, 1200?C e 1250oC para os corpos de prova com a cinza sem calcinar e 1150?C e 1200?C para os corpos de prova com a cinza calcinada com patamar de 60 minutos. Os corpos sinterizados foram caracterizados por absor??o de ?gua, porosidade aparente, retra??o linear, resist?ncia a flex?o e DRX da superf?cie de fratura e os resultados analisados. Ficou comprovado, apos resultado dos ensaios realizados, que e poss?vel a utiliza??o do res?duo da cinza do bala?o da cana de a??car em massas cer?micas de revestimento, com adi??o de ate 10% wt do res?duo da cinza

When firing calcium ceramic materials creates a new crystalline phase anorthite. It can significantly improve the properties of ceramic body. This work deals with the possibilities of development anortitové ceramics using non-plastic raw materials, particularly alumina cement compared with conventional ceramics based on mullite.

>Magister Scientiae - MSc / The Sea Point contact, Cape Town, South Africa, exposes the contact between the Neoproterozoic Malmesbury Group metasedimentary rocks of the Pan-African Saldania belt and the intrusive S-type Peninsula Granite of the Neoproterozoic-Paleozoic Cape Granite Suite (CGS). The exposure outcrops over an area of approximately 170 m × 60 m with the northern end of the exposure being characterized by the country rock–microgranite intrusive contact. Heading further south, the outcrop transitions to the main contact zone, which is a predominantly gradational zone marked by sheets of compositionally variable granitic injections (collectively referred to as hybrid granite phases) concordant to the country rock structure, before reaching the main pluton area comprising the voluminous coarse-grained porphyritic granite. Using a combined study incorporating field, structural, geochemical, isotopic and U-Pb geochronological data, the intrusive contact is investigated to determine the construction history of the pluton and delineate possible emplacement mechanisms. The granitic phases, which vary from fine-grained leucocratic, medium-grained porphyritic to coarse-grained porphyritic, are peraluminous, magnesian to ferroan, and alkali-calcic. Based on the linear trends between the whole-rock major and trace element content of the granites vs. maficity (molar Fe + Mg), their initial Sr ratios and εNd(t) values, the granites of the study area are consistent with the currently proposed petrogenetic model for the CGS (e.g. Stevens et al., 2007; Villaros et al., 2009a; Harris & Vogeli, 2010); i.e., they are crustally derived and their chemical variability is controlled primarily by peritectic assemblage entrainment. The fractional crystallization of K-feldspar is identified as the primary mechanism for the local geochemical variability of the granites. The fractionation of K-feldspar as a mechanism of variability was evaluated using binary log-log diagrams of Ba, Sr and Eu and is interpreted to have taken place at levels close to the emplacement site after source entrainment processes. Although there is outcrop evidence, particularly in the main contact zone, to suggest that local assimilation and filter pressing took place, this was not reflected by the whole-rock and isotope geochemistry of the granites. This suggests that these processes are very localized and will need further rigorous testing to ascertain the extent to which they caused variability. Outcrop evidence for assimilation includes gradational country rock-granite contacts and the ductile behaviour of the country rock, whereas the occurrence of K-feldspar megacrysts embedded in the country rock at the main contact zone suggests melt accumulation and escape consistent with the filter pressing mechanism. In the case of the latter, the melt fraction of the granite was easily mobilized and driven out compared to the crystal fraction (K-feldspars) during the emplacement of the granites. Field relationships and the structural interpretation of the Malmesbury Group country rocks and the granites reveal that: (1) the various granites are late syn-tectonic and (2) were emplaced as incrementally assembled, repeated pulses of inclined granitic sheets more or less normal (i.e. at high angles) to the regional NE-SW shortening (D1) of the Malmesbury forearc during the Saldanian orogeny. Given the lack of a controlling shear zone in facilitating granite emplacement in the study area, the pre-existing planar anisotropies (bedding planes and foliations) in the country rock provided preferential pathways for magma emplacement and propagation during deformation. This implies that the tensile strength normal and parallel to the bedding and foliation anisotropy of the country rock was larger than the regional differential stress (σ1 – σ3, with σ1 ≥ σ2 ≥ σ3), allowing for magma emplacement relative to shortening. Sheet propagation is interpreted to have occurred through the balance of the following conditions: (1) density contrasts between host rocks and magmas, (2) the pressure differential along the subvertical fractures/sheets, and (3) the melt pressure equalling the lithostatic pressure to keep the magma pathways open and being sufficiently high such that it exceeds the sum of σ1 and the tensile strength of the rock parallel to σ1. The crystallization ages of the dated granite samples are identical within error and vary between 538.7 ± 3.6 Ma and 542.7 ± 2.9 Ma. They, therefore, cannot prove which granite phase intruded first and which one proceeded and so forth. Field relationships, however, suggests that the microgranites were first to intrude given their fine-grained nature and the localized chilled contacts they show with the country rock. The various coarser-grained and porphyritic phases were next to intrude, with their coarse grain-sizes and lack of chilled margins with the country rock suggesting that the time interval between their successive emplacements was not too long; this prevented the country rock from completely cooling down between each magma batch. Magma stoping and the ductile flow of the host material (owing to highly viscous magma flow) to accommodate granite emplacement are interpreted to be secondary emplacement processes.

Die sichere Endlagerung hochradioaktiver Stoffe ist weltweit eine der großen Herausforderungen des 21. Jahrhunderts. Der abgebrannte Kernbrennstoff ist hoch-radiotoxisch und stellt somit eine Gefährdung für Mensch und Umwelt dar. Daher muss der radioaktive Abfall für bis zu einer Million Jahre von der Umwelt isoliert werden. International wird dafür die Endlagerung in tiefengeologischen Formationen favorisiert. Für ein solches Endlager für radioaktive Abfälle kommen in Deutschland Salz-, Ton- und Kristallinformationen in Frage, welche aufgrund der verschiedenen mineralogischen und geochemischen Bedingungen Radionuklide (RN) unterschiedlich stark immobilisieren. Wesentliche Prozesse sind dabei Ausfällung, Einbau in Festphasen und Sorption an Mineraloberflächen. Für eine belastbare Risikobewertung möglicher Endlagerstandorte sind geeignete Transportmodelle notwendig, welche auf umfangreiche thermodynamische Daten angewiesen sind. Hierfür sind insbesondere Studien zu Wechselwirkungen (WW) von RN mit Mineralphasen im Kristallingestein, d.h. Quarz, Feldspäten, Glimmern, nicht ausreichend verfügbar. Die minoren Actinide Am und Cm liegen in wässriger Lösung grundsätzlich im dreiwertigen Oxidationszustand vor. Außerdem werden unter den zu erwarteten reduzierenden Bedingungen in einem Endlager auch Np zu einem geringen und Pu zu einem nennenswerten Teil dreiwertig vorliegen. Daher beschäftigt sich der erste Teil der Arbeit mit den WW dreiwertiger Actiniden (An(III) = Am, Cm) mit Feldspäten. Der zweite Teil der Arbeit beschäftigt sich mit dem Einfluss von Elektrolyten auf die Rückhaltung von Actiniden an Mineraloberflächen. Dabei wurde zum einen der Einfluss des natürlich häufig auftretenden, anorganischen Liganden Sulfat auf die Sorption von An(III) an das Schichtsilikat (Glimmer) Muskovit untersucht, sowie in einem weiteren Beispiel der Einfluss der Elektrolytzusammensetzung auf die Sorption des Actinids Thorium an Muskovit untersucht. Th liegt in wässriger Lösung ausschließlich vierwertig vor und wird stark hydrolysiert, wodurch die Bildung polynuklearer Spezies begünstigt ist. Methodisch kommen in diesem Teil der Arbeit neben Oberflächenröntgenbeugung (SXRD) auch Alphaspektrometrie und Rasterkraftmikroskopie (AFM) zum Einsatz. Die Ergebnisse der Arbeit leisten einen signifikanten Beitrag zur realistischen Abschätzung der Mobilität drei- und vierwertiger Actiniden im Kristallingestein. Die Ergebnisse der Arbeit werden in Zukunft Simulationen des reaktiven Transports und somit die Auswahl eines geeigneten Standorts für ein Endlager für radioaktiven Abfall unterstützen.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第18087号 / 理博第3965号 / 新制||理||1572(附属図書館) / 30945 / 京都大学大学院理学研究科地球惑星科学専攻 / (主査)准教授 三宅 亮, 教授 土`山 明, 准教授 河上 哲生 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM