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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.
21

Facing Nature: The Infinite in the Flesh

Vicvang@yahoo.com.au, Robert Daniel Victorin-Vangerud January 2006 (has links)
This thesis explores the relation between two interpretations of chôra, drawn from a reading of Plato’s Timaeus. The first I label the elemental chôra. The second, I call the social chôra. The first chapter addresses the elements in Ionian philosophy, with an eye toward the political and social backdrop of the important cosmological notion of isonomia, law of equals. Here social and elemental are continuous. Chapter two looks at the next phase of Presocratic thought, Elea, specifically Parmenides and his influence on later thought, then turns to Heidegger’s reading of Parmenides’ through the key word of alêtheia. Finally, I offer a reading of Parmenides through a different key word— trust. The third chapter examines Plato’s cosmology in the Timaeus, focusing on the way the beginning of this dialogue inflects the dialogue in a political/social direction, putting the social chôra in tension with the elemental chôra that the body of the Timaeus’ discusses. In the fourth chapter, which examines the Phaedrus, this tension is inverted, since this dialogue on writing and justice set in what proves to be the mesmerizing and erotic elemental milieu of the world outside the walls of the polis. The second half of the dissertation turns to some modern thinkers within the phenomenological tradition or its wake who write about elementals. Chapter five examines Gaston Bachelard’s reveries on imagination which dream the natural world of fire, air, water, and earth from the standpoint of what he calls material and dynamic imagination, concepts that imply a strong sense of embodiment. Chapter six treats Levinas’ description of the elemental and fixes it in a stark relation to the human. I will suggest some possible points of contact between the elemental and the social in Levinas. Chapter seven turns to John Sallis’ analysis of the imagination as the means of access proper to the elemental in ways that differ from Bachelard. He position the earth as a fundamental other. I will suggest that in the end his position inherits Heidegger’s lack of emphasis on embodied and needy humanity. Alphonso Lingis offers his own unique reading of the elemental in a more Levinasian and Merleau-Pontian vein, speaking of the directives the world, both human and natural, puts to us, and returning to a philosophy of substance that puts the body in the picture. Chapter eight uses his thought to focus the issue of the dissertation.
22

Estudio de la Reducción de Azufre Elemental y Producción de Sulfuro de Hidrógeno en Bioreactores Anaeróbicos

Escobar Antoine, Claudio Manuel January 2009 (has links)
No description available.
23

Elemental analysis of Marksville-style prehistoric ceramics from Mississippi and Alabama

Baca, Keith A 03 May 2008 (has links)
Distinctive Marksville-style pottery is characteristic of the Middle Woodland period (200 B.C. – A.D. 500) in the Lower Mississippi River Valley and adjacent regions. Marksville material is common in the Lower Mississippi Valley, and the scarcity of similar pottery in northeastern Mississippi and western Alabama has caused claims that Marksville pots were imported into those areas; however, they may have been locally made. To test these alternative possibilities, the elemental composition of some Marksville-style potsherds, other pottery, and clays from various archaeological sites spanning the above regions was characterized using laser ablation-inductively coupled plasma-mass spectrometry. The results show that the analyzed Marksville-style pottery shares similar elemental profiles with locally common wares and local clays in the sample, allowing the conclusion that all of these Marksville specimens were made in the regions where they were found.
24

The application of elemental tags for biological analyte identification

Easter, Renee N. 23 September 2011 (has links)
No description available.
25

New Chelating Agents based on 8-Hydroxyquinoline

Billo, Edward Joseph 06 1900 (has links)
Several new potentially terdentate chelating agents based on the 8-hydroxyquinoline structure have been synthesized and characterized. Protonation constants of these ligands and formation constants of their chelates with selected metal-ions have been determined. Where possible, the chelates have been characterized by elemental analysis and other means. The results show that the ligand 2-(2'-thienyl)-8-hydroxyquinoline acts as a sterically hindering bidentate donor; the unusual relationship found between the formation constants of its bis-chelates (K1 < K2) has been explained on the basis of steric effects. The results of studies involving 4-amino-5-hydroxy-acridine and 4,5-dihydroxyacridine indicate that these ligands act as terdentate and bidentate donors, respectively. The failure of 4,5-dihydroxyacridine to act as a terdentate donor is explained in terms of chelate-ring strain. / Thesis / Doctor of Philosophy (PhD)
26

Chuaria, Vendotaenia, and the taphonomy of the Carbonaceous Compression

Anderson, Evan Pelzner 21 June 2010 (has links)
Carbonaceous Compressions are a widespread preservational style for fossils, yet their taphonomy remains poorly understood. Previous studies focusing on the taphonomy of carbonaceous compressions have primarily looked at exceptionally preserved faunas in plane view. The precious nature of these fossils leaves destructive techniques of analysis out of the question, but these techniques are necessary if the taphonomy of carbonaceous compressions is to be deciphered. This study analyzes Neoproterozoic carbonaceous compressions from the Yangtze Gorges area in order to address this issue. Chuaria fossils from the Jiulongwan, Sixi, and Sifangtan sections of the Doushantuo Formation and Vendotaenia fossils from the Wuhe and Miaohe sections of the Denying Formation are microchemically analyzed in both plane view and cross section in order to gain a greater understanding of the makeup of carbonaceous compressions. Results confirm and elaborate on previous studies. Likely clay coats are detected on some Chuaria specimens, while they are absent on less thermally mature specimens. Evidence for sulfate reduction in association with carbonaceous compressions is found. Sulfur enrichment, rather than clay coats, is found in association with Vendotaenia fossils. These observations lead to the hypothesis that while organic remains require a very precise set of taphonomic conditions in order to be preserved as carbonaceous compressions, there may be more than one set of conditions that allow for preservation. More studies of a greater taxonomic and taphonomic range of carbonaceous compressions are needed, however, if the mechanisms which control this preservational pathway are to be fully understood. / Master of Science
27

Long Branch Nature Center - modern primitivism and the constructed dialogue of being within nature

Hartle, Brett David 02 December 2014 (has links)
The Architect's first drawn line marks a significant moment where alteration to the site is conceived and intervention with nature is beset. Equilibrium of the natural order; vegetative, habitat, hydrology, and geology are all in a vulnerable state. Rarely do these develop into harmonious balances. More often they are imposed instances. The Industrial Revolution forever changed the relationship between humans and nature, tilting the weight of power towards man. While humans capacity for innovation and destruction have grown enormously, our dependence on the natural cycles and resources of the planet remain and grow more voracious. Yet simultaneously, modern progress has facilitated the physical and psychological detachment of that interdependence. The fundamental elements of our existence are veiled through the efficiency of urbanization and its derivatives of specialization, mass-production, and globalization. This project is an examination of the interrelationship between humans and nature through the lens of civic architecture within a naturalistic setting. The fundamental thesis of this project is that there is a primal biological thread that connects human beings to the natural order, whether on a visceral or conscious level. This project explores the belief that humans intrinsically yearn to reinforce that bond - awakening primordial instincts developed over millions of years of evolutionary survival that have been suppressed by the artifice of modern life. Through a process of retreat and contemplation, this project offers the opportunity of individuals to evaluate and rebalance their own scales with nature and find their own accord and harmony. / Master of Architecture
28

Proveniência das rochas do Grupo Península Trinity, Antártica, como ferramenta para reconstrução da margem Pacífica do Gondwana / not available

Harabari, Andrea Prendalia 07 May 2014 (has links)
As rochas do Grupo Península Trinity e das unidadesequivalentes abrangem arenito, argilito e conglomerado, além de seus correspondentes metamórficos, e cuja formação é atribuída a correntes de turbidez. Afloram na parte norte da Península Antártica e arquipélagos adjacentes. Amostras de arenito, arcósio e conglomerado dessas unidades foram analisadas com intuito de traçar sua proveniência. A partir da análise petrográfica de arenito foi constatada a similaridade entre as rochas das formações do Grupo Península Trinity, Formação Grauvaca-Folhelho e Formação Miers Bluff. As rochas apresentam composição quartzo-feldspática, com baixa porcentagem de fragmentos líticos de composição plutônica, vulcânica e metamórfica. Diferenças composicionais ocorrem na Formação View Point, na qual também ocorre subarcóseo; e na Formação Miers Bluff, arcóseo lítico. As idades U-Pb de grãos detríticos de zircão para as rochas do Grupo Península Trinity da região de Botany Bay são concordantes e a mais jovem é 324 ± 8 Ma, ainda com quantidade expressiva de grãos com idades de 512 a 541Ma e 1001 a 1091Ma. Valores de ?Nd para rocha total, calculados para 220 Ma estão entre -5 e -8, indicando influência de fontes crustais recicladas ou de razoável residência crustal. A extensa gama de idades para a área-fonte indica reciclagem sedimentar de fonte diversa, com idades carboníferas, cambrianas e pré-cambrianas. O ?Hf calculado para as idades de U-Pb dos grãos de zircão detríticos mais jovens variade -1,2 a -5,7, também indicam extensa residência crustal. A amostra da Formação Legoupil, que complementa os dados de idades U-Pb em grãos detríticos de zircão para oGrupo Península Trinity, apresenta idade mais jovem de 265 ± 2, restringindo a idade máxima de sedimentação ao Permiano. Para as amostras da Formação Grauvaca-Folhelho as idades U-Pb em grãos detríticos de zircão apresentam duas concentrações bem definidas, permo-triássica e cambriana, com idade concordante mais jovem de 216 ± 2 Ma e mais antiga de 1,8 ± 0,13 Ga. Essas idades são condizentes com as dos grãos detríticos de zircão do Grupo Península Trinity. A partir dos dados de idades de grãos detríticos dezircão pode-se definir como a idade máxima para deposição para as formações Legoupil e Grauvaca-Folhelho sendo permo-triássica, assim como para as rochas do GrupoPenínsula Trinity em Botany Bay. Idades essas que levam a sugerir como fonte a Patagônia, no maciço Norte-patagônico, e Antártica Ocidental, na Terra de Mary Byrd. Estascondizem tanto em idade como em tipo de fonte, ígnea e metamórfica, com contribuição sedimentar. / The rocks of the Trinity Peninsula Group and equivalent units comprise sandstone, mudstone and conglomerate, as wel as their corresponding metamorphic rocks, whose formation is attributed to turbidity currents. They crop out in the northern Antarctic Peninsula and adjacent islands. Samples of sandstone, arkose and conglomerate of these units were analyzed in order to trace their provenance. From the petrographic analysis of sandstone was found similarity between the rocks of the Trinity Peninsula Group, Greywacke-Shale Formation and Miers Bluff Formation. The rocks have quartz-feldspathic composition, low percentage of lithic fragments of plutonic, volcanic and metamorphic rocks. Compositional differences occur in View Point Formation, which also occurs subarkose, and Miers Bluff Formation, lithic arcóseo. The U-Pb ages dates of detrital zircon grains in the rocks of the Trinity Peninsula Group region of Botany Bay are concordant and the youngest is 324 ± 8 Ma, but concentrations around 512-541Ma and 1001-1091Ma are common. Values of ?Nd calculated for 220 Ma are between -5 and -8, indicating influence of recycled crustal sources or with reasonable crustal residence. With extensive range of ages for the source area, indicating sediment recycling of diverse source areas, with ages spread from Carboniferous to Cambrian and Precambrian. The ?Hf calculated for dates U-Pb of younger detrital zircon ranges from -1.2 to -5.7, also indicate extensive crustal residence. The sample of Legoupil Formation, which complements the U-Pb dates for detrital zircon grains of the Trinity Peninsula Group, presents younger date of 265 ± 2, restricting the maximum age of the sedimentation asPermian. For samples of Greywacke-Shale Formation the U-Pb dates for detrital zircon grains exhibit two well-defined concentrations, permo-triassic and cambrian, with younger concordant date of 216 ± 2 Ma and older of 1.8 ± 0,13 Ga. These dates are consistent with those of detrital zircon grains from the Peninsula Group Trinity. From the data on detrital zircon grains can be defined as the maximum age for deposition for Legoupil and Greywacke-Shale formations being permo-triassic, as well as the rocks of the Trinity Peninsula Group in Botany Bay. Dates that suggest as a source area Patagonia, in Northern Patagonian massif and West Antarctica, in the Mary Byrd Land. These areas are consistent with both in age and rock types, igneous, metamorphic, and sedimentary, as the source area.
29

Chemistry with lasers / Química con láseres

Marillo Sialer, Estephany 18 May 2018 (has links)
El número de aplicaciones de la energía laser en el campo científico crece día a día. Estas no solo se han extendido en los campos de química, física y ciencia de materiales, sino también en biología y medicina. Este artículo es una breve introducción a los principios fundamentales del funcionamiento del láser, así como a su aplicación en el campo de la química. / The number of applications of lasers in science is constantly growing, with applications stretching from chemistry, physics and materials science to biology and medicine. This article provides a short overview of the fundamentals of lasers and an introduction to the application of lasers and laser ablation in chemistry.
30

The importance of elemental stacking order and layer thickness in controlling the formation kinetics of copper indium diselenide

Thompson, John O., 1962- 12 1900 (has links)
xiii, 84 p. ; ill. / This dissertation describes the deposition and characterization of an amorphous thin film with a composition near that of CuInSe 2 (CIS). The creation of an amorphous intermediate leads to a crystalline film at low annealing temperatures. Thin films were deposited from elemental sources in a custom built high vacuum chamber. Copper-selenium and indium-selenium binary layered samples were investigated to identify interfacial reactions that would form undesired binary intermediate compounds resulting in the need for high temperature annealing. Although the indium-selenium system did not form interfacial compounds on deposit, indium crystallized when the indium layer thickness exceeded 15 angstroms, disrupting the continuity of the elemental layers. Copper-selenium elemental layers with a repeat thickness of over 30 angstroms or compositions with less than 63% selenium formed CuSe on deposit. Several deposition schemes were investigated to identify the proper deposition pattern and thicknesses to form the CIS amorphous film. Simple co-deposition resulted in the nucleation of CIS. A simple stacking of the three elements in the older Se-In-Cu at a repeat thickness of 60 angstroms resulted in the nucleation of CuSe and sometimes CIS. The CIS most likely formed due to the disruption of the elemental layers by the growth of the CuSe. Reduction of the repeat thickness to 20 angstroms eliminated the nucleation of CuSe, as predicted by the study of the binary Cu-Se layered samples, but resulted in the nucleation of CIS, similar to the co-deposited samples. To eliminate both the thick Cu-Se region, and prevent the intermixing of all three elements, a more complex deposition pattern was initiated. The copper and selenium repeat thicknesses were reduced into a Se-Cu-Se-Cu-Se pattern followed by deposition of the indium layer at a total repeat thickness of 60 angstroms. At a Se:Cu ratio of 2:1 and the small repeat thickness, no Cu-Se phases nucleated. Additionally, the Cu-In interface was eliminated. For this deposition scheme, films with a selenium rich composition relative to CuInSez were generally amorphous. Those that were Cu-In rich always nucleated CIS on deposit. Annealing of all samples produced crystalline CIS. / Adviser: David C. Johnson

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