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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

Hidden intrusions and molybdenite mineralization beneath the Kucing Liar Skarn, Ertsberg-Grasberg Mining District, Papua, Indonesia

Trautman, Marin Cherise 05 November 2013 (has links)
The Ertsberg-Grasberg Mining District of Papua, Indonesia (Western New Guinea) hosts the Ertsberg Cu-Au Skarn, the giant Grasberg Porphyry Cu-Au deposit, and several other orebodies. Two 1700-meter-long cores beneath the Kucing Liar ore skarn (KL98-10-22) and the Grasberg Igneous Complex (KL98-10-21) contain high concentrations of vein and disseminated molybdenite. KL98-10-22, the focus of this study, intersects two previously unencountered intrusions, the “Tertiary intrusion Kucing Liar” (Tikl) and “Tertiary Pliocene intrusion” (Tpi). An intense dilatational quartz vein stockwork cuts Tikl and Ekmai Sandstone (Kkes) units, predating Tpi intrusion. Prior to these ultradeep cores, which extend almost 3 km below pre-mining surface, molybdenite was rarely observed in the district. Geochemistry and isotopic data indicate that Tikl and Tpi intrusions originated from the same large magmatic system that emplaced other ore-forming Ertsberg-Grasberg district intrusions. Magma in a lower crustal chamber was recharged at least twice, according to Sr-Nd data. Laser-ablation inductively-coupled plasma mass spectrometry of magmatic zircons yields 238U-206Pb ages between 3.40 ± 0.12 Ma (Dalam Andesite) and 2.77 ± 0.15 Ma (Ertsberg intrusion), revealing a shorter period of igneous activity than previously measured by K-Ar and Ar-Ar dating. Analyses include composite ages of 3.28 ± 0.08 Ma for Tikl and 3.18 ± 0.11 Ma for Tpi. Inherited zircon cores indicate Precambrian (mostly Proterozoic) basement. Molybdenite veining beneath the Kucing Liar Skarn and Grasberg Igneous Complex postdates stockwork veining and occurred before the 2.99 ± 0.11 Ma Kali dikes. Only one molybdenite vein was observed cutting Tpi. Molybdenites yielded ~3 Ma Re-Os ages and anomalous >4 Ma and <0.5 Ma ages; anomalous ages were not reproducible in follow-up analyses (this study). Smearing deformation of molybdenite (through fault activity) causes crystal strain, likely leading to annealing recrystallization. Recrystallization possibly redistributes daughter-product Os, resulting in anomalous ages from annealed material. Fluids with high Mo/Cu ratios (which were likely supercritical) precipitated late-stage molybdenite deep in the system. These fluids developed through magma chamber crystallization, which concentrated molybdenum in the melt as an incompatible element, and stripping of Cu from the magma chamber during hydrothermal activity. / text
142

Hidden intrusions and molybdenite mineralization beneath the Kucing Liar Skarn, Ertsberg-Grasberg Mining District, Papua, Indonesia

Trautman, Marin Cherise 05 November 2013 (has links)
The Ertsberg-Grasberg Mining District of Papua, Indonesia (Western New Guinea) hosts the Ertsberg Cu-Au Skarn, the giant Grasberg Porphyry Cu-Au deposit, and several other orebodies. Two 1700-meter-long cores beneath the Kucing Liar ore skarn (KL98-10-22) and the Grasberg Igneous Complex (KL98-10-21) contain high concentrations of vein and disseminated molybdenite. KL98-10-22, the focus of this study, intersects two previously unencountered intrusions, the “Tertiary intrusion Kucing Liar” (Tikl) and “Tertiary Pliocene intrusion” (Tpi). An intense dilatational quartz vein stockwork cuts Tikl and Ekmai Sandstone (Kkes) units, predating Tpi intrusion. Prior to these ultradeep cores, which extend almost 3 km below pre-mining surface, molybdenite was rarely observed in the district. Geochemistry and isotopic data indicate that Tikl and Tpi intrusions originated from the same large magmatic system that emplaced other ore-forming Ertsberg-Grasberg district intrusions. Magma in a lower crustal chamber was recharged at least twice, according to Sr-Nd data. Laser-ablation inductively-coupled plasma mass spectrometry of magmatic zircons yields 238U-206Pb ages between 3.40 ± 0.12 Ma (Dalam Andesite) and 2.77 ± 0.15 Ma (Ertsberg intrusion), revealing a shorter period of igneous activity than previously measured by K-Ar and Ar-Ar dating. Analyses include composite ages of 3.28 ± 0.08 Ma for Tikl and 3.18 ± 0.11 Ma for Tpi. Inherited zircon cores indicate Precambrian (mostly Proterozoic) basement. Molybdenite veining beneath the Kucing Liar Skarn and Grasberg Igneous Complex postdates stockwork veining and occurred before the 2.99 ± 0.11 Ma Kali dikes. Only one molybdenite vein was observed cutting Tpi. Molybdenites yielded ~3 Ma Re-Os ages and anomalous >4 Ma and <0.5 Ma ages; anomalous ages were not reproducible in follow-up analyses (this study). Smearing deformation of molybdenite (through fault activity) causes crystal strain, likely leading to annealing recrystallization. Recrystallization possibly redistributes daughter-product Os, resulting in anomalous ages from annealed material. Fluids with high Mo/Cu ratios (which were likely supercritical) precipitated late-stage molybdenite deep in the system. These fluids developed through magma chamber crystallization, which concentrated molybdenum in the melt as an incompatible element, and stripping of Cu from the magma chamber during hydrothermal activity. / text
143

The evolution of the alchemical androgyne in symbolist and surrealist art

Grew, Rachael January 2010 (has links)
The relationship between Symbolism and Surrealism is well known yet scarcely documented in detail. This thesis aims to address this oversight by exploring the connections between these two movements, specifically through investigating their shared motif of the androgyne. The androgyne embodies the professed aim of each of these groups: the transcendence of the physical in favour of the ephemeral for the Symbolists, and the unification of opposites for the Surrealists. Equally, both movements have an interest in the occult, and the androgyne is a key image within the occult tradition symbolising spiritual unity, dovetailing with the Symbolists’ and the Surrealists’ goals. The androgyne will be analysed firstly within the context of alchemy, surveying the way in which it is portrayed in primary sources, and how this has changed in Symbolist and Surrealist art. It will also be analysed in the contexts of psychoanalysis and gender identity, observing how male and female artists portray the androgyne differently and why. The aim of this thesis is therefore two-fold: firstly, a comparative study of the iconography employed by these connected movements, to original alchemical sources, and also between the male and female artists of these movements. Secondly, it aims to create a more secure basis for the notion of alchemical influence on Symbolism and Surrealism.
144

From Neighborhoods To Wellbeing And Conservation: Enhancing The Use Of Greenspace Through Walkability

Zuniga Teran, Adriana Alejandra January 2015 (has links)
In drylands, it is essential to maximize the coupling of social and ecological systems in order to achieve sustainability, particularly in human dominated landscapes such as cities. The enhanced use of greenspace in cities in drylands provides unique opportunities to maximize the coupling of social and ecological systems. It maintains the functioning of ecological systems while involving civil society in the conservation of biodiversity and improving human wellbeing in urban settings. The provision and access to greenspace in cities is determined by neighborhood design. The access for the human use of greenspace can be enhanced through walkability, or the characteristics of the built environment that influence physical activity. Walkable neighborhoods that provide access to greenspace can be catalysts for activity and health and have the potential to increase the level of conservation support in urban residents. The purpose of this research is to look for wellbeing and conservation synergies between walkable neighborhoods and the enhanced use of greenspace. To accomplish this research, first we assess walkability in the built environment through an interdisciplinary literature review that integrates the findings on walkability from several research domains. We create a conceptual framework that organizes the neighborhood design elements that influence physical activity into nine walkability categories: connectivity, land-use, density, traffic safety, surveillance, parking, experience, greenspace, and community. We call this the Walkability Framework. This analysis allows us to identify gaps and strengths of walkability in the Leadership for Energy and Environmental Design for Neighborhood Development (LEED-ND) certification system. After a quantitative and qualitative analysis, we propose an enhanced version for walkability that we call LEED-NDW+ (walkability plus). The next step is to test if the Walkability Framework can be used as a model to measure the interactions between the built environment and physical activity. We accomplish this through the use of a questionnaire (N=486) that captures the perceptions, attitudes and behaviors of residents in Tucson, Arizona. Significant correlations between all the walkability categories and physical activity support the use of the framework as a model. We call this the Walkability Model. The final stage of this research uses the Walkability Model to evaluate walkability in four neighborhood design types in Tucson that include traditional development, suburban development, enclosed community, and cluster housing. We then look for wellbeing and conservation synergies between walkable neighborhoods and the enhanced use of greenspace. Results from this study suggest that neighborhoods with a high level of walkability have the potential to enhance the use of greenspace, which in turn provide important wellbeing and conservation synergies that can contribute to healthier communities and increase the support for conservation of biodiversity within and beyond cities. The enhanced use of greenspace maximizes the coupling of social and ecological systems in cities in drylands, which increases resilience in the face of climate change.
145

An assessment of the impact of current language policy pertaining to adult basic education and training at Phindangene adult education centre (Lamontville).

Nkabinde, Cyril Thamsanqa. January 2002 (has links)
Public policy can take a wide range of forms, from broad statements of goals to more specific statements of intention (De Clercq 1997 cited in Kallaway et al 1997). Policy can be expressed in speeches, official statements, court decisions, laws and regulations, all of which embody the authority to define goals and priorities. Policy also provides a framework for taking action and lends legitimacy to implementation and evaluation purposes (Ray and Poonwansie 1987 cited in Ovando, 1999). The outcomes of a policy depend critically on the resources allocated to its support and the institutional arrangements mobilized in its implementation. Despite the introduction and implementation of the new Language in Education Policy (1997), policies and legislation enacted by the new government in South Africa to redress the imbalances of the past, especially in terms of promoting the marginalized African languages, and recognising language diversity and choice, the status and use of African languages in schools has not improved. The purpose of this study was to examine the impact of the current language policy on an adult centre that is Phindangene Adult Centre. This study sought to investigate learners and teachers attitudes towards the Language In Education Policy. It also aimed to demonstrate how language choices were made at Phindangene AEC, and whose interests they served. Different research instruments were used for data collection. A written questionnaire and semi-structured interviews were used to gather data from the respondents. Observation and official records were also used to supplement this. This study showed that there was a big difference between the language policy of the country and language practice at Phindangene AEC. In the light of the major findings the study recommends the following: • Student's primary language should be incorporated into the instructional program. • A holistic approach to teacher development should be adopted which provides teachers with basic skills and concepts in curriculum development through seminars and workshops. • Much more effort should go into developing and providing learning materials and textbooks that are more appropriate to adult learners. • School governing bodies need to familiarize themselves with the new Language in Education Policy. • It is the responsibility of the Department of Education to make sure that each adult centre gets a copy of the language policy. / Thesis (M.Ed.) - University of Natal, 2002
146

THE EVOLUTION OF GRENVILLE BASEMENT IN THE EASTERN GREAT SMOKY MOUNTAINS; CONSTRAINTS FROM U-PB ZIRCON GEOCHRONOLOGY, WHOLE ROCK SM-ND, AND FELDSPAR PB GEOCHEMISTRY

Quinn, Ryan Joel 01 January 2012 (has links)
Identifying the crustal affinity of Grenville basement rocks in the Dellwood quadrangle, western NC, provides insight into the tectonic evolution of eastern Laurentia during Grenville orogenesis. U-Pb zircon geochronology of orthogneiss, augen gneiss, and mafic xenoliths in orthogneiss reveal magmatic pulses at 1130, 1180, and 1330 Ma and metamorphic episodes at 450 and 1040 Ma. Xenoliths in 1330 Ma orthogneiss are as old as 1382 Ma and represent the oldest component of Blue Ridge basement identified to-date. Feldspar Pb isotope values span a range between juvenile-Laurentian and southern-central Appalachian basement/Amazonia. Most Pb isotope data define an array consistent with crustal mixing between Laurentia and Amazonia, however, one xenolith has a unique Pb isotopic composition interpreted as Laurentian crust. Sm-Nd isotope data yield depleted mantle model ages ranging from 1.52 to 1.79 Ga (200 to 650 Ma older than their crystallization ages) indicating a broadly non-juvenile heritage for Dellwood basement. Three biotite gneiss samples contain detrital zircon grains derived from 1060, 1160, 1330, and 1750 Ma sources. Multiple magmatic zircon age populations, variable depleted mantle modelages, and regionally unique isotopic Pb signatures are evidence of protracted Grenville magmatism in the southern Appalachians involving both Laurentian and Amazonian crustal components.
147

Variabilité chimique et isotopique créée par les processus sédimentaires dans les sédiments de rivière Himalayennes

Garcon, Marion 23 November 2012 (has links) (PDF)
Les compositions isotopiques en Nd, Hf, Pb et Sr des sédiments de rivière sont souvent considérées comme étant représentatives de celles de leurs roches sources. Elles sont donc largement utilisées pour tracer la provenance des sédiments ou pour moyenner les compositions isotopiques des lithologies drainées. L'influence des processus sédimentaires sur les compositions isotopiques de ces sédiments est cependant mal connue. L'objectif de l'étude présentée ici est de caractériser l'ampleur de la variabilité isotopique pouvant être générée par les processus de tri minéralogique au cours du transport des sédiments dans le milieu fluviatile. Pour ce faire, nous avons analysé les concentrations en éléments traces et les compositions isotopiques en Nd, Hf, Pb et Sr dans différents types de sédiments de rivière (bedload, suspended load, bank) échantillonnés à plusieurs endroits dans le système fluviatile du Ganges qui draine une partie de l'orogène Himalayenne. Nous avons également mesuré les compositions chimiques et isotopiques de nombreuses fractions minérales et granulométriques séparées de ces sédiments afin de mieux comprendre l'influence de chaque espèce minérale dans le budget isotopique total d'un sédiment de rivière. Dans le cas où les lithologies drainées sont essentiellement cristallines et sédimentaires, nous montrons que les isotopes du Nd dans les sédiments de rivière sont très peu affectés par les processus de tri minéralogique puisqu'ils sont toujours contrôlés par les mêmes minéraux, à savoir la monazite et l'allanite. Au contraire, les systèmes isotopiques de l'Hf, du Pb et du Sr s'avèrent particulièrement touchés par les processus de tri minéralogique. Les isotopes de l'Hf et du Pb sont tous deux affectés par un effet zircon qui génère de larges variations isotopiques entre les sédiments de fond de rivières et ceux transportés en suspension. Pour le Sr, les variations observées entre les différents types de sédiments résultent des proportions variables de micas et feldspath-K qu'ils contiennent. Dans le cas où les principales lithologies drainées présentent de forts contrastes d'érodabilité i.e. basaltes versus roches cristallines, nous montrons que les effets combinés de l'érosion différentielle dans le bassin de drainage et du tri sédimentaire dans la colonne d'eau sont responsables d'importantes variations isotopiques en Nd, Hf et Pb entre les sédiments de fond de rivière et ceux transportés en suspension. Nos calculs suggèrent que les produits d'érosion basaltique, relativement fins, sont préférentiellement transportés en suspension, proche de la surface de l'eau, alors que les produits d'érosion des roches plus cristallines sont préférentiellement concentrés dans les sédiments de fond de rivière. Enfin, nous suggérons que les variations isotopiques observées entre les différents types de sédiments transportés par les rivières sur les continents pourraient avoir d'importantes implications pour les systématiques isotopiques des sédiments océaniques terrigènes et sur l'évolution à long terme du réservoir mantellique si ces derniers sont recyclés au niveau des zones de subduction.
148

A Geochemical and Isotopic Investigation of Metasedimentary Rocks from the North Caribou Greenstone Belt, Western Superior Province, Canada

Duff, Jason 30 April 2014 (has links)
The North Caribou Greenstone Belt (NCGB) lies at the core the granitoid-dominant North Caribou Terrane (NCT). Two sedimentary assemblages; the Eyapamikama (ELS) and Zeemal-Heaton Lake (ZHA) form the core of the NCGB. Geochemistry of garnets from the orogenic Au deposit at Musselwhite suggest that the auriferous fluids have a contribution of metamorphic fluids and mineralization consisted of prolonged, multi-stage periods. Chemical zoning suggests changes in the influx of chalcophile and lithophile elements and that Au/sulphide ratios during nucleation were lower relative to later growth events. Zircons from the ELS and ZHA suggest a c. 100 My hiatus in the onset of sedimentation, with the ZHA showing younger, “Timiskaming-type” ages. Age distributions from each assemblage reflect proximal, igneous sources. Nd isotopic compositions of the ZHA suggest a mixture of ancient and contemporaneous sources which are similar to external TTG rocks. Deplete mantle model ages of the ZHA rocks indicate a Mesoarchean inheritance.
149

Transformation And `europeanization`of Greek Political Culture: The Case Of Political Parties Between 1974-2000

Alkan, Hulya 01 April 2004 (has links) (PDF)
This thesis analyses the &lsquo / dualistic&rsquo / structure of Greek political culture formed by traditionalist and modernist wings in a historical context by concentrating on post-1974 era. The dissolution of the dictatorship in 1974 constituted a turning point both for Greek politics and Greek political culture. In this point, political parties played the key role in the process of transition and consolidation of democracy and reshaping Greek political culture. Accession into the EC was another historical step for Greek politics and political culture. Deepening of integration with the EC (EU) and Europeanization process has profoundly affected socio-political, economic structure and institutional modernization of Greece. Europeanization of Greece reformulated the hegemony struggle between traditionalist and modernist wings in favor of the latter. Especially, coming to power of Simitis with a pro-European understanding and &lsquo / modernization&rsquo / discourse reinforced the hegemony of modernist wing over the traditionalist one.
150

Ocorrência de opacidade de cápsula posterior em cães pós-facoemulsificação, com ou sem a utilização de lente intraocular dobrável e efeitos do Nd: Yag Laser

Conceição, Luciano Fernandes da [UNESP] 15 July 2014 (has links) (PDF)
Made available in DSpace on 2015-04-09T12:28:07Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-07-15Bitstream added on 2015-04-09T12:48:22Z : No. of bitstreams: 1 000814977.pdf: 648645 bytes, checksum: 30e76402fd013eac04392612d142190b (MD5) / A catarata elenca-se entre as afecções oculares mais freqüentes em cães, sendo a facoemulsificação o método que melhor se adequa à sua terapia. As opacidades de cápsula posterior (OCPs) estão entre as complicações mais comuns e se manifestam em semanas ou meses após a facectomia. Lentes intraoculares (LIOs), empregadas na correção da hipermetropia pós-cirúrgica, são citadas como úteis na prevenção das OCPs, especialmente as acrílicas dobráveis, com bordas truncadas ou quadradas. Entretanto, quando OCPs se estabelecem requerem-se capsulotomias como forma de tratamento. Em pacientes humanos, reconhecem-se os efeitos do Nd:YAG laser como técnica não invasiva e segura frente a tais intercorrências. Para se compararem resultados de olhos de cães que receberam lentes intraoculares acrílicas dobráveis com olhos de cães afácicos, após facoemulsificação, durante um período de 180 dias, utilizaram-se 20 cães de raças diversas, machos ou fêmeas, que variaram de 3 a 7 anos de idade, apresentando catarata juvenil , imatura ou madura (imatura n = 10 , madura n = 10) bilateral. Dois grupos (G1 = com implante de lente intraocular e G2 = sem implante de lente artificial) foram formados aleatoriamente e todos os cães tiveram ambos os olhos operados. Após a cirurgia, os pacientes foram avaliados, semanalmente, quanto a presença ou a ausência de sinéquias, discoria, pressão intraocular, inflamação uveal e presença ou não de opacidade de cápsula posterior durante um período de 180 dias. Aos 60, 90, 120, 150 e 180 dias após a cirurgia, imagens da cápsula posterior foram capturados para avaliação da sua opacidade. Olhos com score 2 ou 3 de opacidade foram submetidos à terapia de capsulotomia pelo Nd:YAG laser. Variáveis categóricas ordinais foram comparadas (G1 X G2) empregando-se o teste de qui-quadrado e o teste exato de Fisher. Variáveis quantitativas foram comparadas empregando-se ANOVA com pós teste de Tukey / Cataracts are among the most common eye diseases in dogs, being the phacoemulsification method the one that best suits in their therapy. The posterior capsule opacification (PCOs) are among the most common complications and manifest themselves in weeks or months after cataract surgery. Intraocular lenses (IOLs) used in the correction of postoperative hyperopia, are mentioned as useful in the prevention of PCOs , especially the foldable acrylic ones with truncated or square edges. However, when PCOs are set up, capsulotomies are required as a treatment. In human patients, the effects of the Nd:YAG laser are recognized as a noninvasive and secure technique against such problems. To compare the results of eyes of dogs that received foldable acrylic intraocular lenses with eyes of aphakic dogs, after phacoemulsification, during a period of 180 days it was used 20 dogs of several breeds, male or female , ranging from 3 to 7 years old , with juvenile, immature or mature (n = 10 immature, mature n = 10) bilateral cataracts . Two groups (G1 = with implantation of intraocular lens and G2 = no artificial lens implant) were randomly formed and all dogs had both eyes operated. After the surgery, the patients were weekly evaluated for the presence or absence of synechiae, discoria, intraocular pressure, uveal inflammation and presence or absence of posterior capsule opacification during a period of 180 days. At 60, 90, 120, 150 and 180 days after surgery, the posterior capsule images were captured for evaluation of their opacity. Eyes with score 2 or 3 of opacity were underwent to capsulotomy by Nd:YAG laser. Ordinal categorical variables were compared (G1 X G2) using the chi-square and Fisher´s exact test. Quantitative variables were compared using ANOVA with Tukey post test. Synechiae were observed in the same frequency in both groups .G2 showed 30 % more discoria when compared to G1 Intraocular pressure did not differ between the groups. The ...

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