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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.
81

Tectônica da conexão do Cinturão Ribeira com a Faixa Araçuaí - Divisa Rio de Janeiro/Espírito Santo / Tectonic connection beetwen the Ribeira and Araçuaí Belts at the boundary of Rio de Janeiro and Espírito Santo

Tiago da Rocha Karniol 09 December 2008 (has links)
A investigação geológica-estrutural de duas seções transversais ao Cinturão Ribeira, no norte do Rio de Janeiro e sul do Espírito Santo, revela que a região caracteriza-se por um regime tectônico transpressivo, o qual pode ser reconhecido, principalmente, a partir da análise geométrica e cinemática dos elementos estruturais. Neste trecho do orógeno, observa-se uma curvatura das principais estruturas, de NE para NNE, relacionadas à articulação, a sul, com o lineamento de Além Paraíba. Essa geometria, em escala regional, pode ser relacionada a uma cinemática destral, considerando-se, como referência, o Cráton do São Francisco. Na seção Italva (RJ) - Muriaé (MG), as principais evidências da tectônica transpressiva referem-se à articulação entre zonas de cisalhamento de alto ângulo, predominantemente direcionais e com movimentação para SW, paralela ao orógeno, principalmente no seu setor oriental, e zonas de cisalhamento de ângulo intermediário com lineação frontal e movimentação extensional de topo para ESE. Na seção Marechal Floriano - Ibatiba (ES), as zonas de cisalhamento apresentam movimentação predominantemente oblíqua com componente direcional destral que refletem a propagação do fluxo tectônico para SSW, como pode ser observado, entre outras, na zona de cisalhamento de Guaçuí. Foram reconhecidas também estruturas sinistrais que podem representar indícios de uma movimentação antitética nessas zonas. Nas duas seções investigadas, a partição da deformação reflete-se na alternância entre zonas de máxima deformação, formadas por rochas tipicamente miloníticas, e zonas intermediárias de mais baixa deformação, onde predominam corpos de rochas intrusivas. Além disso, o padrão anastomosado, por vezes em leque, das estruturas planares, bem como sua complexa relação com os elementos lineares, é atribuído ao caráter transpressivo da deformação. Os granulitos com granada investigados na região no norte do Rio de Janeiro indicam um equilíbrio químico com temperatura entre 700 e 780 °C e pressão entre 7,9 e 9,3 kbar, resultado substancialmente superior aos intervalos de 600-670 °C e 5,7-6,7 kbar, obtidos para gnaisses de associações aluminosas, na porção leste da seção. Esse contraste nos resultados geotermobarométricos, consistentemente mais elevados considerando-se o centro dos minerais em relação às bordas, juntamente com a caracterização cinemática e as feições microestruturais são evidências da ocorrência, neste setor orogênico, de um processo de exumação mais acentuada no conjunto dos granulitos. Num regime transpressivo associado à colisão oblíqua de placas ou terrenos, esse processo pode ser explicado pela extrusão de porções da crosta inferior em regime dúctil, cinematicamente articuladas por zonas de cisalhamento extensionais, como as caracterizadas neste trabalho. Tomando como referência os dados apresentados, atribuídos a um regime de deformação transpressiva durante o Neoproterozóico, considera-se arbitrário o emprego do paralelo 21° Sul como limite entre a Faixa Araçuaí e o Cinturão Ribeira. As diferenças em relação à articulação cinemática, nas duas seções estudadas, indicam uma variação do quadro de deformação no sentido longitudinal. Essas diferenças podem ser compreendidas por mudanças das condições de contorno, como a geometria do bloco rígido e variações reológicas impostas por taxas variadas de fusão das rochas, que levaram a extrusão com preservação parcial de paragêneses granulíticas da crosta inferior no segmento estudado. / Litho-structural characterizations carried out on two transverse sections of the Neoproterozoic Ribeira Belt, in the north portion State of Rio de Janeiro and southern State of Espírito Santo, southeastern Brazil, show that it represents part of the transpressive dextral orogen related to the Central Mantiqueira Province. NNE-trending and steeply-dipping regional mylonitic belts describe a map-scale, S-C-like structure that is characterized by their deflection towards NE near the Além Paraíba shear zone. This geometry is consistent with oblique continental collision considering the São Francisco Craton as a reference. In the Italva (RJ) - Muriaé (MG) section, the shear zones on its eastern part present predominant top to SW, parallel-to-the-orogen, transpressive movements and top-down-to-ESE tectonics on the central-western part of the section related to intermediary-dipping shear zones with frontal lineation. The main shear zones on the Marechal Floriano - Ibatiba (ES) section describe oblique movements with dextral component and top-to-SW tectonic flow, as described in the Guaçuí shear zone. At some outcrops, sinistral structures may reflect antithetic movements on these zones. Lithological and structural control related to deformation partitioning lead to the formation of milonites and felsic mylonitic granulites in ductile shear zones, alternated with less deformed intermediate to basic granulites with charnockitic lenses. Indeed, the anastomosed geometry and fan-like pattern of planar structures, as well as the complex relation with linear elements, may be a result of the transpressive shear. The garnet granulites on the northern region of Rio de Janeiro present chemical equilibrium from 700 to 780 °C and from 7.9 to 9.3 kbar which is higher than the intervals of 600-670 °C and 5,8-6,7 kbar obtained for aluminous gneisses on the eastern portion of the section. These differences on geothermobarometric results, mostly higher considering the nuclei of minerals in relation to its borders, the kinematic characteristics and microstructural pattern of samples suggest a more elevated exhumation rate for the granulites in this orogenic segment. Considering a transpressive regime related to oblique tectonic plates or blocks collision, this process can be explained by the ductile extrusion of infracrustal portions as shown by extensional shear zones described in this work. Because of our investigations, we think that the limit of Ribeira and Araçuaí belts on parallel 21° South, as considered by some authors, is arbitrary. The contrasts on kinematics on both studied sections point to longitudinal variations of deformation path that may reflect boundary condition changes, like the geometry of the craton and rheologic transitions of rocks caused by differential partial melting, that lead to extrusion tectonics with partial preservation of granulitic parageneses on the investigated segment.
82

Une histoire comptable et financière de la ligne ferroviaire dite de la « petite ceinture » Paris (1853-2014) : Approche par les théories de la décision / An accounting and financial history of the said railroad line of "The small belt" in Paris (1853-2014) : approach by the theories of the decision

Dhoiffir, Loutfi 07 February 2015 (has links)
La ligne de Petite Ceinture de Paris est un ancien chemin de fer à double voie de 32 kilomètres de longueur (hors raccordements) qui faisait le tour de Paris à l’intérieur des boulevards des Maréchaux. Ouverte par tronçons de 1852 à 1869, elle est d’abord exclusivement consacrée au trafic de marchandises avant d’être ouverte au trafic de voyageurs, à l’exception de la ligne d’Auteuil, à l’inverse directement ouverte aux voyageurs en 1854 et seulement en 1867 pour les marchandises. Désertée par les Parisiens en raison de la concurrence croissante du métropolitain à partir de 1900, la ligne est, pour l’essentiel de son parcours, fermée au trafic de voyageurs le dimanche 22 juillet 1934, hormis la ligne d’Auteuil, restée ouverte jusqu’en 1985. Le trafic de marchandises a également disparu depuis le début des années 1990, et la ligne est aujourd’hui en grande partie abandonnée et amputée d’une partie de sa longueur. Une portion de la ligne d’Auteuil a toutefois été intégrée en 1988 à la ligne C du RER. De nombreuses gares ont été détruites dont Montsouris. La gare de Passy a été conservée en étant transformée en restaurant. Des gares ont été converties comme la gare de Charonne. Restée à l’abandon depuis 1993, la Petite Ceinture a fait l’objet d’une première phase de concertation en 2013 afin d’en esquisser l’avenir. Notre travail de recherche s’inscrit au coeur de ce débat du devenir de la Petite Ceinture de Paris. Il vise à démontrer l’importance de cette emprise ferroviaire depuis sa création en 1852 jusqu’à sa fermeture en 1934 pour le service de voyageurs. Nous proposons une analyse comparative de la situation de la gestion comptable et financière depuis 1854 à 1934 pour déterminer les différents résultats d’exploitation réalisés afin d’évaluer la performance financière de la ligne. Notre démarche consiste à comprendre pourquoi des hommes intelligents, en possession de tous leurs moyens, ont-ils pu prendre la décision d’interrompre volontairement l’activité de la ligne Petite Ceinture. Quels sont les conséquences de la mise en jachère de très long terme de cette plate-forme ferroviaire ? Quels sont les manques à gagner de cette mise en sommeil ? Peu de recherches se sont basées sur cette démarche, et notre travail de recherche était d’étudier les différentes approches de la décision fondées sur les théories de la décision rationnelle de Simon, de Cyert et de March et sur les théories de la décision absurde de Christian Morel. Après confrontation de ces différentes approches, nous avons tiré comme résultat pour échapper à la non décision, l’application de la théorie de la métarègle de la fiabilité. / The Line Little Belt is a former Paris railway line double track 32 kilometers in length (excluding connections) who went around Paris within the boulevards of the Marshals. Opened by sections 1852 to 1869, it is first devoted exclusively to freight traffic before being opened for passenger traffic, with the exception of the Auteuil line, unlike directly open to travelers in 1854 and only in 1867 for goods. Deserted by Parisians because of growing competition from the Metropolitan in 1900, the line is, for most of his career, closed to passenger traffic Sunday, July 22, 1934, except the Auteuil line remained open until in 1985. Freight traffic has disappeared since the early 1990s, and the line is now largely abandoned and missing a portion of its length. A portion of the Auteuil line, however, was built in 1988 to the RER C line. Many stations were destroyed including Montsouris. Passy Station has been preserved by being converted into a restaurant. Stations were converted as station Charonne. Remained abandoned since 1993, the Little Belt has been the subject of a first phase of consultation in 2013 in order to sketch the future. Our research is at the heart of the debate about the future of the Little Belt Paris. It aims to demonstrate the importance of the railway line since its inception in 1852 until it closed in 1934 for passenger service. We provide a comparative analysis of the situation of the accounting and financial management from 1854 to 1934 to determine the different results of operations conducted to evaluate the financial performance of the line. Our approach is to understand why intelligent men, in possession of all their resources, they have taken the decision to voluntarily stop the activity of theLittle Belt line. What are the consequences of setting aside of the very long term of this railway platform? What are theshortfalls of this Sleep? Little research has been based on this approach, and our research was to study the differentapproaches to the decision based on the theories of rational decision of Simon of Cyert and March and the absurd theories of decision Christian More l . After comparison of these different approaches, we have learned as a result to escape the non-decision, applying the theory of meta-rule of the reliability.
83

Cretaceous-Paleogene Low Temperature History of the Southwestern Province, Svalbard, Revealed by (U-Th)/He Thermochronometry: Implications for High Arctic Tectonism

Barnes, Christopher January 2016 (has links)
The High Arctic has been a complex region of collisional and extensional tectonism through the Mesozoic and Cenozoic. Svalbard, the sub-aerial exposure of the northwestern Barents Shelf, is an excellent natural laboratory investigating for High Arctic tectonism. Using apatite and zircon (U-Th)/He low-temperature thermochronometry combined with geological constraints, we resolve Cretaceous through Paleogene time-temperature histories for four regions of the Southwestern Province. Our results indicate a temperature gradient from south to north of ~185°C to >200°C, respectively, as a consequence of sedimentary burial and elevated geothermal gradient ( 45°C/km) from High Arctic Large Igneous Province activity. Late Cretaceous cooling affected all regions during regional exhumation related to initial rifting in the Eurasian Basin. During Eurekan tectonism: 1) our models indicate a heating event (55-47 Ma) characterized by overthrusting and a lack of erosion of the West Spitsbergen Fold-and-Thrust Belt, with Central Basin sediments derived from northern Greenland, followed by 2) a subsequent cooling event (47-34 Ma) corresponding to a shift in tectonic regime from compression to dextral strike-slip kinematics; exhumation of the WSFTB coincided with strikeslip tectonics.
84

Transformation of tonalitic gneiss into potassic garnet-sillimanite gneiss in a deep crustal shear zone in the Limpopo belt

Mokgatlha, Kgomotso P.B. 17 November 2014 (has links)
M.Sc. (Geology) / Please refer to full text to view abstract
85

The tectonic evolution of the rocks comprising the Venetia Klippe, Limpopo Belt, South Africa, with emphasis on carbonate and calc-silicate rocks and pegmatite

Twiggs, C. 16 August 2012 (has links)
M.Sc. / This thesis involves a study ofthe geology surrounding the —530 Ma to —519 Ma Venetia kimberlite pipes situated between AIldays and Messina (now renamed Musina) in the Beit Bridge Terrane of the Limpopo Belt, South Africa. The Limpopo Belt is an eastnortheast trending high grade metamorphic terrane thought until recently to be the result ofa collisional event between the Kaapv_aal and Zimbabwe Cratons between 2.7 and 2.65 Ga. However, recent studies have challenged this concept and suggest that the assembly was more complex and took place over an extended period of time ending at —2.04 Ga. This study involved surface mapping of the Farms Rugen (south) and Ostrolenca, providing additional information to help with mine planning, grade control and exploration. It forms a portion of a project initiated between Venetia Mine, the Venetia- Limpopo Nature Reserve and Professor Jay Barton of RAU to geologically map in detail the area around the pipes (scale < 1:10 000) and to study various aspects of the regional geology. The rock types into which the Venetia kimberlite pipes intruded belong to the Venetia klippe, an east-west trending synclinal structure with the axial plane dipping steeply northwards. Lithologically, the Venetia klippe comprises four layered units in which interlayered granitic or arkosic quartzofeldspathic gneisses, with and without biotite and garnet, and para and ortho-amphibolite, quartzite and meta-carbonate rocks (marble and limestone), banded iron formation and calc-silicate rock occur. Geochemical analysis (SEM and electron microprobe) of the meta-carbonates (re-crystallised magnesian limestone, coarse-grained marble and fine-grained foliated marble), indicate the precursors to be magnesian limestone, dolomite and limestone. Several events have been identified during the structural evolution of the area. They include: formation of gneissic metamorphic layering, tectonic suturing between different lithologies, formation of a syncline and east-west strike-slip faulting, north-south trending folds and northeast-southwest dextral strike-slip faulting, tourmaline bearing pegmatite emplacement, dolerite intrusion, tourmaline absent pegmatite emplacement, kimberlite emplacement and reactivation of pre-existing structures. Depositional structures only in the fine-grained foliated marble are preserved, e.g. graded bedding, cross-bedding, rip-up clasts and channels. These structures suggest deposition of the carbonates in two main depositional environments; peritidal (channels and rip-up clasts) and subtidal shelf (graded bedding and cross-bedding). A study of pegmatites in the area shows two main pegmatite types: tourmaline bearing and tormaline absent, each locally displaying a zonation. Mineralogically, the pegmaties are rich in quartz and albite and lack K-feldspar so they are classified as sodic-rich or plagio-pegmatites. Step heating 40Ar/39Ar analyses of muscovite from undeformed pegmatite yields an age of —2.0 Ga, which is interpreted to represent the time of pegmatite emplacement into the Venetia klippe rocks. Structurally, the pegmatites are sheet-like bodies cross-cutting compositional layering, joints, faults, folds and the dolerite, except for the older tourmaline bearing pegmatite that has intruded along east-west faults, but not northeast-southwest trending faults. By applying the principles of a dike propagation model, the source of the Venetia pegmatites should be greater than 5X5X5 km in volume and a maximum of 10km away. An appropriate granitic source has been recognized on the farm Gotha to the south of the mine by Martina Barnett. Leucocratic granodiorite, tonalite and granite with minor xenoliths of amphibolite, quartzite and magnetite quartzite define the Gotha Granitic Complex and pegmatite decreases in abundance away from it to the north and east. Deposition of Unit 3 lithologies into a rifted basin and an ancient epeiric sea is possible. However, there is more evidence (peritidal and shelf environments of the metacarbonates) and clean mature quartzites to suggest deposition into a passive continental margin or epeiric sea similar to the Malmani dolomites of the Transvaal Supergroup.
86

The role of airphoto and satellite image interpretation in analysing volcanic landforms and structures in the eastern part of the Trans Mexican Volcanic Belt, Mexico /

Werle, Dirk. January 1984 (has links)
No description available.
87

Simulation und Analyse ringgespannter Zahnriemengetriebe

Bankwitz, Hagen 03 November 2014 (has links) (PDF)
Die Arbeit befasst sich mit der Simulation von Zweiwellen-Zahnriemengetrieben und deren Vorspannmethoden, insbesondere mit der relativ neuen Methode Spannring (ROLL-RING®). Das Ziel der vorliegenden Arbeit ist es, ein analytisches Simulationsmodell zu entwickeln, mit dem grundlegende Erkenntnisse über das statische und dynamische Verhalten solcher ringgespannten Zahnriemengetriebe gewonnen werden können. Für einen exemplarischen Vergleich der Vorspannmethoden, werden außerdem analytische Simulationsmodelle für Zahnriemengetriebe ohne Spannelement und mit federgespannter Rolle erstellt. Als weiteren Bestandteil der vorliegenden Arbeit wird eine Dimensionierungsvorschrift für ringgespannte Zahnriemengetriebe abgeleitet, bei der sowohl statische als auch dynamische Vorgänge im Getriebe berücksichtigt werden können. Anschließend wird der Einfluss der relevanten Parameter auf das Verhalten des ringgespannten Getriebes untersucht. Alle erstellten Simulationsmodelle werden sowohl experimentell an Versuchsständen als auch mittels FEM-Vergleichsrechnung validiert. Die dafür benötigten Getriebeparameter wurden ebenfalls experimentell ermittelt. Abschließend folgt der exemplarische Vergleich der Vorspannmethoden anhand von drei Simulationsbeispielen und einem experimentellen Vergleich des Wirkungsgrads. / This dissertation deals with the simulation of two-shaft timing belt drive and its pre-tension methods. Special attention is given to the relatively new method tensioning ring (ROLL-RING®). The target of the present work is to develop an analytical simulation model, with this fundamental understanding of the static and dynamic behavior of such ring-tensioned timing belt drives can be gained. For an exemplary comparison of pre-tension methods, analytical simulation models for synchronous belt drive without pre-tension element and with tensioner pulley with spring will be created. As another part of the present work a dimensioning specification for ring-tensioned toothed belt drives was deduced. This specification can be considered in both static and dynamic processes in the transmission. Then, the influence of relevant parameters on the behavior of the ring-tensioned timing belt drives is researched. All created simulation models will vali-date both experimental and FEM using comparative calculation. The parameters re-quired for the transmission were also experimentally determined. Finally, the exemplary comparison of pre-tensioned methods basis of three examples of simulation and an ex-perimental comparison of energy conversion efficiency follow.
88

Correlates Of Seat Belt Use Among Turkish Front Seat Occupants

Simsekoglu, Ozlem 01 July 2005 (has links) (PDF)
CORRELATES OF SEAT BELT USE AMONG TURKISH FRONT SEAT OCCUPANTS SimSekoglu, &Ouml / zlem M.S., Department of Psychology Supervisor: Assoc. Prof. Dr. Timo Lajunen June, 2005, 79 pages This thesis included three separate studies, which were observational, interview and survey studies, on seat belt use among Turkish front seat occupants. The observation study investigated occupant characteristics and environmental factors affecting seat belt use. Seat belts were used significantly more among females and older occupants than among males and younger occupants / and on intercity roads, at weekends and in the afternoons than on city roads, at weekdays and in the evenings. The interview study investigated the common reasons for using and not using a seat belt in different trip types, qualitatively. Safety, situational conditions, habit and avoiding punishment were the commonly reported reasons for using a seat belt, while situational conditions, not believing the effectiveness of seat belt use, discomfort and no habit of using a seat belt were the commonly reported reasons for not using a seat belt, for most of the trip types. In the third study, seat belt use both on urban and rural roads were explained with the basic and extended Theory of Planned Behavior (TPB) models and Health Belief Model (HBM), using Structural Equation Modeling. Basic TPB model showed a good fit to the data, while extended TPB model and HBM showed a low fit to the data. Within TPB constructs, attitudes and the subjective norm had a positive and significant relation to intentions to use a seat belt. Results were discussed for their implications to traffic safety in Turkey, along with limitations of the study and suggestions for further studies.
89

Fluid-induced charnockite formation post-dating prograde granulite facies anatexis in southern Natal metamorphic province, South Africa

Saunders, Brenton Mark 24 April 2014 (has links)
M.Sc. (Geology) / The Proterozoic Namaqua-Natal Mobile Belt of southern Africa represents a succession of high grade metamorphosed igneous and sedimentary rocks rimming the southern and western extents of the Kaapvaal craton. Different petrological processes associated with the onset of granulite facies metamorphism were investigated with the emphasis on the processes on anatexis and migmatitization and the influence of the fluid phase on these processes. The investigation took place in the Margate Terrane of the Southern Natal Metamorphic Province. The Umzimkulu and Louisiana Quarries near Port Shepstone formed the bulk of the field area for this investigation. The Umzimkulu and Louisiana quarries expose two s-type granitic lithologies, namely, the Glenmore Biotite Gneiss (GBGn) and the slightly younger, intrusive Margate Leucogranite (MLGn), both of which have been metamorphosed to granulite facies. Geothermobarometric calculations on the metamorphism of the Margate Terrane all indicate temperatures and pressures of peak metamorphism be 850oC+50oC at +6 kbar. The high grade metamorphic history of the lithologies is recorded by the formation of concordant, lens-shaped, prograde anatectic leucosomes. The leucosomes are concentrically surrounded by biotite selvage zones, followed by melanosomes, and lastly undisturbed host rock material. This investigation revealed that the formation of both the charnockite veins and the prograde leucosomes occurred through processes of anatexis. Field relations suggest that the charnockitic veins formed in situ, and were structurally controlled, which is evident from their linearity. Petrographic and geochemical data provide evidence for melt involvement. This is in strong contrast to theories of charnockite formation ascribed to subsolidus granulite formation by the flushing of host lithologies by a pervasive, carbonic fluid, as has been suggested to have occurred in Southern India. The so-called "incipient charnockites" of Southern India are both morphologically and geochemically similar to the charnockite veins described in the SNMP, suggesting that an anatectic origin may be common to both.
90

Pohon pásového dopravníku pro transport uhlí / Drive of coal transport belt conveyor

Kliš, Kamil January 2013 (has links)
This diploma thesis deals with designing a drivetrain for a coal belt conveyor. Thesis contains necessary calculations according to norms needed for determining suitable components of a belt conveyor. The goal of this diploma thesis was to design a drivetrain for a belt conveyor, all its components including a frame of the drivetrain and to create drawing documentation.

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