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Age and Tectonic Evolution of the Amdo Basement: Implications for Development of the Tibetan Plateau and Gondwana PaleogeographyGuynn, Jerome January 2006 (has links)
The elucidation of the geologic processes that led to the creation of the Tibetan Plateau, a large area of thick crust and high elevation, is a fundamental question in geology. This study provides new data and insight on the geologic history of central Tibet in the Jurassic and Cretaceous, prior to the Indo-Asian collision, as well as the Gondwanan history of the Lhasa and Qiangtang terranes of the plateau. This investigation is centered on the Bangong suture zone near the town of Amdo and I present new geochronology, thermochronology, thermobarometry and structural data of the Amdo basement, an exposure of high-grade gneisses and intrusive granitoids. Using a range of thermochronometers, I show there were two periods of cooling, one in the Middle-Late Jurassic after high-grade metamorphism and a second in the Early Cretaceous. I attribute Middle-Late Jurassic metamorphism, magmatism, and initial cooling of the Amdo basement to arc related tectonism that resulted in tectonic or sedimentary burial of the magmatic arc. I propose that a second period of cooling, nonmarine, clastic sedimment deposition and thrust faulting in the Early Cretaceous is related to the Lhasa-Qiangtang collision. The thermochronology reveals limited denudation between the Cretaceous and the present, indicating the existence of thickened crust when India collided with Asia in the early Tertiary. U-Pb geochronology of the orthogneisses and detrital zircon geochronology of metasedimentary rocks suggests that the Lhasa and Qiangtang terrane were located farther west along Gondwanan's northern margin than most reconstructions depict.
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Ion Mobility Mass Spectrometry of DNA/SgrAI Nuclease OligomersMa, Xin January 2012 (has links)
SgrAI is a restriction endonuclease (ENase) that cuts a long recognition sequence and exhibits self-modulation of cleavage activity and sequence specificity. Previous research has shown that SgrAI forms large oligomers when bound to particular DNA sequences and under the same conditions where SgrAI exhibits accelerated DNA cleavage kinetics. However, the detailed structure and stoichiometry of SgrAI:DNA as well as the basic building block of the oligomers, has not been fully characterized. Ion mobility mass spectrometry (IM-MS) was employed to analyze SgrAI/DNA complexes and show that the basic building block of the oligomers is the DNA-bound SgrAI dimer (DBD). The oligomers are heterogeneous containing a mixture of species with variable numbers of DBD. The collision cross sections (CCS) of the oligomers were found to have a linear relationship with the number of DBD. Models of the SgrAI/DNA oligomers were constructed and a head-to-tail arrangement was most consistent with the experimental CCS.
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Testing alternative models of continental collision in Central Turkey by a study of the sedimentology, provenance and tectonic setting of Late Cretaceous-Early Cenozoic syn-tectonic sedimentary basinsNairn, Steven Peter January 2011 (has links)
In central Anatolia, Turkey, a strand of the former northern Neotethys Ocean subducted northwards under the Eurasian (Pontide) active margin during Late Cretaceous–Early Cenozoic time. Subduction and regional plate convergence were associated with the generation and emplacement of accretionary complexes and supra-subduction zone-type ophiolites onto former passive margins of microcontinents. The resultant suture zones contain Late Cretaceous to Middle Eocene basins (“The Central Anatolian Basins”) including: 1) the Kırıkkale Basin; 2) the Çankırı Basin, 3) the Tuz Gölü Basin and; 4) the Haymana - Polatlı Basin. Using stratigraphic logging, igneous geochemistry, micropalaeontology and provenance studies, this study tests two end-member models of basin evolution. In model one, the basins developed on obducted ophiolitic nappes following closure of a single northern Neotethys Ocean during the latest Cretaceous. In model two, northern Neotethys comprised two oceanic strands, the İzmir-Ankara-Erzincan Ocean to the north and the Inner Tauride Ocean to the south, separated by the Niğde-Kırşehir microcontinent, which was rifted from the Gondwana continent to the south. In this scenario, the basins developed as accretionary-type basins, associated with north-dipping subduction which persisted until the Middle Eocene when continental collision occurred. Where exposed, the basements of the Central Anatolian Basins comprise the Ankara Mélange, a mainly Upper Cretaceous subduction-accretion complex and the western/northern margin of the Niğde-Kırşehir microcontinent. New geochemical data from the composite basement of the Kırıkkale Basin identify mid ocean-ridge basalt (MORB), here interpreted to represent relict Upper Cretaceous Neotethyan oceanic crust. During the latest Cretaceous, the Kırıkkale and Tuz Gölü Basins initiated in deep water above relict MORB crust and ophiolitic mélange, bordered by the Niğde-Kırşehir microcontinent to the east where marginal facies accumulated. Further west, the Haymana-Polatlı Basin represents an accretionary-type basin constructed on the Ankara Mélange. To the north, the Çankırı Basin developed on accretionary mélange, bounded by the Pontide active margin to the north. Palaeocene sedimentation was dominated by marginal coralgal reef facies and siliciclastic turbidites. Latest Palaeocene–middle Eocene facies include shelf-type Nummulitid limestone, shallow-marine deltaic pebbly sandstones and siliciclastic turbidites. This thesis proposes a new model in which two north-dipping subduction zones were active during the late Mesozoic within northern Neotethys. In the south, ophiolites formed above a subduction zone consuming the Inner Tauride Ocean until the southward retreating trench collided with the northern margin of the Tauride continent emplacing ophiolites and mélange. In the north, subduction initiated outboard of the Eurasian margin triggering the genesis of supra-subduction zone ophiolites; the subduction zone rolled back southwards until it collided with the Niğde-Kırşehir microcontinent, again emplacing ophiolites during latest Cretaceous time. Neotethyan MORB still remained to the west of the Niğde-Kırşehir microcontinent forming the basement of the Kırıkkale and Tuz Gölü Basins. Latest Palaeocene–middle Eocene regional convergence culminated in crustal thickening, folding, uplift and strike-slip faulting which represent final continental collision and the geotectonic assembly of central Anatolia.
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Phenolic oxime copper complexes : a gas phase investigationRoach, Benjamin David January 2011 (has links)
This thesis explores the use of mass spectrometry to define the strengths, and understand solution phase speciation of phenolic oxime-based solvent extractants of the types used in the hydrometallurgical recovery of copper. Chapter 1 reviews briefly the current extraction technology for copper and focuses on hydrometallurgy and the use of phenolic oximes such as 5-nonylsalicylaldoxime. The modification of the latter to improve extraction efficiency is discussed, focussing on the introduction of X-substituents in the 3 position of the benzene ring. Modern mass spectrometry techniques are also discussed with a focus on their application to inorganic systems and their use in achieving the aims of this thesis, as defined above. The work described in chapter 2 involves the development of collision induced dissociation (CID) techniques to determine the relative gas phase stabilities of copper complex anions of the type [Cu(L)(L-H)]-, where LH is a 5-alkyl-3-X-2- hydroxybenzaldehyde oximes and X a range of substituents. The importance of interligand interactions in the outer-coordination sphere and their influence on gas phase anion stability, as defined by CID, is reported. The work described in Chapter 2 on CID is extended in chapter 3 and looks at the effect of charge, of ligand type, LH, and of the nature of the metal on the stability of ionic forms of [M(L)2] complexes, where LH is extended to include 5-alkyl-2- hydroxyphenylethanone oximes. The effects of substitution at the azomethine carbon atom and at the 3-position of the benzene ring and of variation of the nature of the metal on the ion dissociation mechanisms are shown to have a major influence on ion stability under CID conditions. In chapter 4 density functional theory calculations have been used to investigate the influences of substitution at the azomethine carbon atom and at the 3-position of the benzene ring and of variation of the nature of the metal on the gas phase structures of the neutral complexes, [M(L)2]. Gas phase deprotonation and dimerisation enthalpies of the ligands, LH, and enthalpies of formation of [M(L)2] complexes have been calculated and correlates with experimentally determined ligand extraction strength. The ligand type has been extended to include 3-X-2-hydroxybenzaldehyde hydrazones, which have previously been shown to have lower distribution coefficients for copper than the analogous 3-X-substituted oximes. The calculated gas phase formation enthalpies for [M(L)2] show a strong correlation with the strengths as extractants LH, measured as their pH0.5 values for metal uptake. Chapter 5 considers whether mass spectrometry can be used to define the solution equilibria when two different oxime-based ligands, LXH and LYH, compete for Cu(II) in a single phase solution. It has been established that shifts in the relative peak intensities of deprotonated ions derived from the Cu(II) complexes, [Cu(LX)2], [Cu(LY)2] and [Cu(LX)(LY)] reflect changes in the solution composition. The work described in chapter 6 extends the study of solution phase speciation using mass spectrometry. When the Cu(II) and proton concentrations of solutions were varied distinct changes in the resulting electrospray mass spectra were observed and the resulting species were identified using CID and high resolution mass spectrometry. A novel, [Cu3(L-H)3-μ3-O/OH]- species is determined to be a major component of solutions where Cu(II) concentrations are equal to/greater than the LH concentration. Various 3-X-2-hydroxybenzaldehyde oximes (X = CH2NR2) were synthesised. The incorporation of a protonatable arm in the 3-position enabled trinuclear complexes, [Cu3(L-H)3-μ3-OH], to be isolated and fully characterized, including two X-ray determined crystal structures.
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Cloth simulation and collision detection using geometry images07 June 2012 (has links)
M.Sc. (Computer Science) / A challenge faced when simulating the complex behaviour of cloth, especially at interactive frame rates, is maintaining an acceptable level of realism while keeping computation time to a minimum. A common method used to increase the performance is to decrease the number of nodes controlling the cloth's movement. This results in a significant decrease in the time taken to calculate each frame of the animation, but at the cost of sacrificing detail that can only be obtained using a dense discretisation of the cloth. A simple, efficient and popular method to simulate cloth is the mass-spring system, which utilises a regular grid of vertices representing discrete points along the cloth's surface. The structure of geometry images is similar, which makes them an ideal choice for representing arbitrary surface meshes in a cloth simulator whilst retaining the effciency of a mass-spring system. This dissertation presents a novel method of applying geometry images to cloth simulation in order to obtain cloth motion for surface meshes while retaining the simplicity of a massspring model. By adapting an implicit/explicit integration scheme, and utilising the regular structure of geometry images, an improvement in performance is achieved. Additionally, the cloth is able to drape over other objects, also represented as geometry images. The proposed method is efficient enough to allow fairly dense cloth meshes to be simulated in real-time.
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Chaucer's Collision MontageSimmons, Brandon 13 May 2016 (has links)
Sergei Eisenstein’s theory of collision montage can be applied to The Canterbury Tales because Chaucer’s writing is highly visual and often unconventional. This study analyzes several portraits and tales to demonstrate Chaucer’s literary collision montage technique. The opening lines of the General Prologue present the juxtaposition of the tripartite plant and humans to suggest commoners’ social immobility. The interruption of the Miller’s Tale clashes with the Knight’s to suggest the possibility of social mobility and to challenge traditional patriarchy. The latter half of the narrator’s description in the Wife of Bath’s portrait indicates a sexualized subtext through the juxtaposition of neutral images that undercuts her wealthy appearance. Chaucer’s literary collision montage technique is used to suggest the possibility of social mobility, and to reflect the disruption of the social hierarchy in late fourteenth-century England.
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Swept areas and collision detection with application to autonomous vehiclesSundberg, Sofia January 2005 (has links)
This thesis presents an algorithm for collision detection for an autonomous articulated vehicle following pregenerated paths in a mining environment. Two types of vehicles are studied. The tricycle vehicle and the articulated vehicle. The characteristics of the mine is presented. A way of using these characteristics is studied. An algorithm for collision detection using the swept area of the vehicle following a pregenerated path is given. As proof of concept a small implementation is also given along, with a few examples. / Validerat; 20101217 (root)
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Avaliação de interface de reação e colisão para eliminar interferências poliatômicas na análise de etanol combustível por ICP-MS /Neves, Denise Regina das. January 2010 (has links)
Orientador: José Anchieta Gomes Neto / Banca: Márcia Andréia Mesquita Silva da Veiga / Banca: Joaquim de Araujo Nóbrega / Resumo: A espectrometria de massa com plasma acoplado indutivamente empregando interface de reação/colisão (CRI-ICP-MS) foi avaliada para determinação simultânea de Al, Ba, Co, Cu, Cr, Fe, Mg, Mn, Mo, Na, Ni, Pb, Sb, Si, V e Zn em etanol combustível. Para as análises, amostras de etanol combustível foram diluídas vinte vezes de modo a conter 1% v/v de ácido nítrico e 10 μg L-1 Y utilizado como padrão interno. As calibrações foram feitas por ajuste de matriz utilizando etanol P.A.. Como gás de reação/colisão utilizou-se o hidrogênio e como gases auxiliares foram utilizados argônio e oxigênio. A CRI foi fundamental para a determinação da maioria dos analitos, principalmente Fe, Cr, Si e Mg. A escolha da melhor vazão do gás e a otimização dos parâmetros instrumentais foram estudadas utilizando soluções etanólicas contendo 10 μg L-1 dos analitos. Os limites de detecção para 27Al, 138Ba, 59Co,63Cu, 55Mn, 98Mo, 23Na, 58Ni, 208Pb, 121Sb, 51V e 64Zn em etanol por CRI-ICP-MS utilizando 20 mL min-1 de H2 no skimmer foram 0,2; 0,1; 0,005; 0,3; 0,02; 0,05; 0,8 0,2; 0,01; 0,1; 0,4 e 0,3 μg L-1, respectivamente. Os limites de detecção para 52Cr, 56Fe, 24Mg, 28Si em etanol utilizando 60 mL min-1 de H2 no skimmer foram 0,2; 0,1; 0,2 e 13,9 μg L-1. A validação do método foi feita por meio de testes de adição e recuperação dos analitos. Os intervalos de recuperação encontrados para 27Al, 138Ba, 59Co, 63Cu, 55Mn, 98Mo, 23Na, 58Ni, 208Pb, 121Sb, 51V, 64Zn, 52Cr, 56Fe, 24Mg, 28Si se apresentaram entre 78 e 114% / Abstract: The use of inductively coupled plasma mass spectrometry with collision/reaction interface (CRI) was evaluated for simultaneous determination of Al, Ba, Co, Cu, Cr, Fe, Mg, Mn, Mo, Na, Ni, Pb, Sb, Si, V e Zn in ethanol fuel. Samples were diluted 1:20 v/v in a solution containing 1% v/v nitric acid and 10 μg L-1 Y used as internal standard. For all elements the instrument was operated in CRI-ICP-MS mode. The use of CRI was mandatory for Fe, Cr, Si e Mg. Hydrogen was evaluated as the reaction/collision gas and argon and oxygen were used as auxiliary gas. Selection of best reaction gas flow rate and optimization of the instrumental parameters were carried out using ethanolic solutions containing analytes at 10 μg L-1. Limits of detection for 27Al, 138Ba, 59Co, 63Cu, 55Mn, 98Mo, 23Na, 58Ni, 208Pb, 121Sb, 51V e 64Zn in ethanol fuel by CRI-ICP-MS using 20 mL min-1 H2 in the skimmer cone 0.2; 0.1; 0.005; 0.3; 0.02; 0.05; 0.8; 0.2; 0.01; 0.1; 0.4 and 0.3 μg L-1, respectively. The detection limits for 52Cr, 56Fe, 24Mg, 28Si using 60 mL min-1 H2 in the skimmer cone were respectively 0.2; 0.1; 0.2 and 13.9 μg L-1. Method validation was accomplished by the addition and recovery studies. Recoveries found for 27Al, 138Ba, 59Co, 63Cu, 55Mn, 98Mo, 23Na, 58Ni, 208Pb, 121Sb, 51V e 64Zn, 52Cr, 56Fe, 24Mg, 28Si were within the 78 - 114% interval / Mestre
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Collision Broadening of Microwave Spectral Lines of Monomeric Formaldehyde and Formic AcidVenkatachar, Arun C. 08 1900 (has links)
Line width parameters for a number of spectral lines in the pure rotational spectrum of formaldehyde (CH20) and formic acid (HCOOH) have been measured using a sourcemodulated microwave spectrograph. All transitions studied in this investigation were of the type ΔJ=O (i.e. Q-branch transitions), with ΔK-1=0 and ΔK+1 =+l. The center frequencies of the measured lines varied from 8662.0 MHz to 48612.70 MHz. The experimentally determined collision diameters for self broadening interactions involving HCOOH and CH2 Q molecules were found to be 2 - 27 per cent less than those calculated by the Murphy-Boggs theory of collision broadening. Much better agreement between a simplified broadening scheme for symmetric top molecules and the observed foreign-gas collision diameters is obtained by using Birnbaum's theory.
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Existence of a Periodic Brake Orbit in the Fully SymmetricPlanar Four Body ProblemLam, Ammon Si-yuen 01 June 2016 (has links)
We investigate the existence of a symmetric singular periodic brake orbit in the equal mass, fully symmetric planar four body problem. Using regularized coordinates, we remove the singularity of binary collision for each symmetric pair. We use topological and symmetry tools in our investigation.
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