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Arcabouço crustal profundo da parte Centro-Norte da margem de Angola: modelo de afinamento e contato de crostas / Deep crustal framework of North-Central margin of Angola: a model for thinning and crustal transitionLuiz Carlos Lucena Empinotti 27 October 2011 (has links)
Este trabalho tem como objetivo a identificação de feições que permitam (1) a construção do arcabouço crustal profundo e da porção superior do manto em parte da Costa de Angola, (2) a comparação deste arcabouço com o embasamento aflorante e (3) a tentativa de adequar estes resultados aos modelos de ruptura continental já publicados. Para alcançar estes objetivos foi feita a interpretação de cinco linhas sísmicas de reflexão profundas (25 Km de profundidade) na costa de Angola, nas Bacias de Kwanza e Baixo Congo, adquiridas pela ION-GXT. As feições identificadas na sísmica de reflexão auxiliaram na determinação dos limites da crosta continental superior e inferior, no reconhecimento das camadas que compõem a crosta oceânica e na identificação da Descontinuidade de Mohorovicic (que marca o limite entre crosta e manto). A interpretação sísmica associada a dados da literatura (que proporcionaram valores de densidade para os pacotes identificados na interpretação sísmica) permitiram a realização de uma modelagem gravimétrica que foi comparada ao dado gravimétrico adquirido durante a aquisição sísmica. A modelagem gravimétrica serviu para validar a interpretação sísmica, atuando como um controle de qualidade para a interpretação. Caso a anomalia gravimétrica gerada pela modelagem não estivesse de acordo com a anomalia medida, a interpretação sísmica era revista na tentativa de um melhor ajuste entre o resultado modelado e o medido. Este ajuste, no entanto, sempre foi feito honrando os refletores que estavam bem marcados na sísmica. Somado a isto, ainda foi utilizado o dado magnético adquirido no campo, no auxilio da interpretação. O arcabouço crustal obtido com a utilização deste método permitiu a comparação dos resultados da interpretação com os modelos de evolução de margens passivas existentes na literatura, mostrando muitos pontos em comum aos modelos que defendem a possibilidade de ocorrência de manto exumado em margens passivas pobres em magmatismo. A interpretação final destes dados mostrou um domínio proximal marcado por uma crosta continental espessa porém pouco afinada em contato com um domínio distal marcado por uma crosta continental muito afinada (crosta hiper-estirada) e, em direção ao centro do oceano, uma região em que ocorre a exumação do manto. A passagem do domínio proximal para o distal ocorre de forma rápida em uma região denominada Zona de Estrangulamento. À oeste do manto exumado é possível identificar a crosta oceânica. O cruzamento dos resultados obtidos neste trabalho com dados do embasamento aflorante no continente africano sugerem um controle do deste nos valores finais de afinamento da crosta continental sob a bacia e nas regiões de manto exumado. Trabalhos recentes realizados na costa de Angola e do Brasil mostram feições semelhantes às identificadas nesta dissertação. / The main objectives of this study are to identify features on seismic data that allow (1) the building of a deep crustal framework and of the upper portion of the mantle, in part of the Angolan margin; (2) to compare this framework with the adjacent outcropping basement of the African continent and; (3) to try to fit these results to the published continental breakup models. In order to achieve these objectives, five deep reflection seismic lines (25 km of depth) situated in the in Kwanza and Lower Congo Basins on the passive margin of Angola were interpreted. The features identified on seismic were useful to recognize the tripartite division that caracterize the oceanic crust and in defining the Mohorovicic Discontinuity (that represents the limit between crust and mantle). The seismic interpretation associated with the data obtained from the scientific literature (that provided density values for the packages identified on seismic interpretation) allowed the establishment of a gravity modeling that was compared to the gravity data acquired during the seismic acquisition. The gravity model was useful to validate the seismic interpretation, acting as a quality control of the latter. In case of the gravity anomaly generated by the modeling not being in accordance with the measured anomaly, the seismic interpretation was revised in order to obtain a better adjustment between the modeled and the measured result. This adjustment, however, was always done honoring the reflectors that were clearly positioned on seismic. In addition, the magnetic data acquired on the field was used to help on interpretation. The crustal framework obtained by the methodology described above was compared with the passive margin evolution models found on scientific literature, showing some points in common with the models that postulate the occurrence of exhumed mantle in magma-poor passive margins. The final interpretation of these data showed the existence of a proximal domain characterized by a thick continental crust slightly thinned in contact with a distal domain marked by a hyper-extended continental crust. Oceanwards there is a region where the exhumation of the mantle took place. The passage of the proximal to the distal domain is abrupt, here termed as a Necking Zone. Oceanic crust is identified to the west of exhumed mantle. The comparison of the results obtained in this study with data from the outcropping basement on the African continent suggests a basement control on the vales of continental crust thinning attained under the basins and on the regions of exhumed mantle. Recent works done on the Angolan and Brazilian margins show features similar to the ones identified on this dissertation.
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Miocene climate as recorded on slope carbonates : examples from Malta (Central Mediterranean) and Northeastern Australia (Marion Plateau, ODP LEG 194)John, Cédric Michaël January 2003 (has links)
Im Rahmen dieser Doktorarbeit wurden die Hangkarbonate von zwei miozänen heterozoischen Karbonatsystemen näher untersucht: die Malta Inselgruppe (zentrales Mittelmeer) und das Marion Plateau (Nordost Australien, ODP Leg 194). Die Auswirkungen der mittelmiozänen Abkühlung (Mi3), die auf 13.6 Ma datiert wird und starken Einfluß auf die Sauerstoffisotopenkurve hatte, in den oben genannten Flachwassersystemen stellten das Ziel dieser Arbeit dar. Dieses Abkühlungsereignis beeinflußte außerdem sehr stark die ozeanographischen und klimatischen Muster, die im weiteren Verlauf zum modernen Eishausklima führten. So steht insbesondere die Vereisung von Ostantarktika mit diesem Ereignis in Verbindung. Diese Arbeit untersucht den Einfluß dieses Ereignisses auf Flachwassersysteme, um vorliegende Untersuchungen in Tiefwassersystemen zu ergänzen und so zum globalen Verständnis des miozänen Klimawechsels beizutragen.<br />
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Die Profile auf der Maltainselgruppe wurden mit Hilfe von Kohlenstoff- und Sauerstoffisotopen Auswertungen im Gesamtgestein, Gesamtgesteinmineralogie, Tonmineralanalyse und organischer Geochemie untersucht. Durch einen Wechsel von karbonatischeren zu tonigeren Sedimenten beeinflußte das mittelmiozäne Abkühlungsereignis die Sedimentation in diesem Gebiet sehr stark. Weiterhin wurde beobachtet, daß jede Phase der antarktischen Vereisung, nicht nur das mittelmiozäne Hauptereignis, zu einem erhöhten terrigenen Eintrag in den Hangsedimenten der Maltainselgruppe führte. Akkumulationsraten zeigen, daß dieser erhöhte terrigene Eintrag den einzelnen Vereisungsperioden zusammenhängt und die karbonatischen Sedimente durch tonreiche Sedimente “verunreinigt” wurden. Das daraufhin entwickelte Modell erklärt diesen erhöhten terrigenen Eintrag mit einer nordwärtigen Verlagerung der innertropischen Konvergenzzone durch die Bildung von kalten, dichten Luftmassen, die zu verstärkten Niederschlägen in Nordafrika führten. Diese verstärkten Niederschläge (oder verstärkter afrikanischer Monsun) beeinflußten die kontinentale Verwitterung und den Eintrag, mit der Folge, daß verstärkt terrigene Sedimente im Bereich der Hangsedimente der Maltainselgruppe abgelagert wurden. Die tonreichen Intervalle weisen Ähnlichkeiten zu sapropelischen Ablagerungen auf, was mit Hilfe der Spektral analyse des Karbonatgehalts und der geochemischen Analyse des organischen Materials gezeigt wurde. <br />
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Auf dem Marion Plateau wurden die Sauerstoff- und Kohlenstoffisotopenkurven anhand von Foraminiferen der Gattung Cibicidoides spp. rekonstruiert. Der Karbonatgehalt wurde mit Hilfe einer chemischen Methode (Coulometer) ermittelt. Genauso wie die Sedimente der Maltainselgruppe beeinflußte das mittelmiozäne Abkühlungsereignis (Mi3) auch die Sedimente auf dem Marion Plateau. So kam es bei 13,8 Ma, in etwa zur Zeit der Vereisung von Ostantarktika, zu einem Abfall der Karbonatakkumulationsraten. Weiterhin traten Änderungen in der Zusammensetzung der Sedimente auf, so nehmen neritische Karbonatfragmente ab, der planktische Foraminiferengehalt nimmt zu und es wurden verstärkt Quarz und Glaukonit abgelagert. Ein überraschendes Ergebnis ist die Tatsache, daß der große N12-N14 Meeresspiegelabfall um 11,5 Ma die Akkumulationsraten der Karbonate auf dem Hang nicht beeinflußte. Dieses Ergebnis ist umso erstaunlicher, da Karbonatplattformen normalerweise sehr sensitiv auf Meeresspiegeländerungen reagieren. Der Grund, warum sich die Karbonatakkumulationsraten schon um 13,6 Ma (Mi3) und nicht erst um 11,5 Ma (N12-N14) verringerten, liegt in der Tatsache, daß die ozeanischen Strömungen die Karbonatsedimentation auf dem Hang des Marion Plateau schon im Miozän kontrollierten. Das mittelmiozäne Ereignis (Mi3) erhöhte die Stärke diese Strömungen und als eine Ursache wurde die Karbonatakkumulation auf den Hängen reduziert. Die Amplitude des N12-N14 Meeresspiegelabfalls liegt bei 90 m unter der Berücksichtigung der Sauerstoffisotopendaten aus der Tiefsee und Berechnungen des Meeresspiegels anhand des “coastal onlaps”, die während Leg 194 gemacht wurden. Die Isotopendaten dieser Arbeit weisen hingegen auf einen verringerten Meeresspiegelabfall von 70 m hin.<br />
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Als allgemeine Schlußfolgerung kann gesagt werden, daß der mittelmiozäne Klimaumschwung die Karbonatsysteme zumindest an den beiden untersuchten Lokalitäten beeinflußt hat. Allerdings waren die Auswirkungen sehr von den unterschiedlichen lokalen Gegebenheiten abhängig. Insbesondere wirkten sich die Anwesenheit einer Landmasse (Malta) und die Abwesenheit einer Barriere vor den Einflüssen des offenen Ozeans (Marion Plateau) stark auf die Ablagerung der Karbonate aus. / This study investigated the slope carbonates of two Miocene carbonate systems: the Maltese Islands (in the Central Mediterranean) and the Marion Plateau (Northeastern Australia, drilled during ODP Leg 194). The aim of the study was to trace the impact of the Miocene cooling steps (events Mi1-Mi6) in these carbonate systems, especially the Mi3 event, which took place around 13.6 Ma and deeply impacted the marine oxygen isotope record. This event also profoundly impacted oceanographic and climatic patterns, eventually leading to the establishment of the modern ice-house world. In particular, East Antarctica became ice covered at that period. The rational behind the present study was to investigate the impact that this event had on shallow water systems in order to complement the deep-sea record and hence acquire a more global perspective on Miocene climate change.<br />
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The Maltese Islands were investigated for trends in bulk-rock carbon and oxygen isotopes, as well as bulk-rock mineralogy, clay minerals analysis and organic geochemisty. Results showed that the mid Miocene cooling event deeply impacted sedimentation at that location by changing sedimentation from carbonate to clay-rich sediments. Moreover, it was discovered that each phase of Antarctic glaciation, not just the major mid Miocene event, resulted in higher terrigenous input on Malta. Mass accumulation rates revealed that this was linked to increased runoff during periods when Antarctica was glaciated, and thus that the carbonate sediments were “diluted” by clay-rich sediments. The model subsequently developed to explain this implies feedback from Antarctic glaciations creating cold, dense air masses that push the ITCZ Northward, thus increasing precipitation on the North African subcontinent. Increased precipitation (or stronger African monsoon) accelerated continental weathering and runoff, thus bringing more terrigenous sediment to the paleo-location of the slope sediments of Malta. Spectral analysis of carbonate content and organic matter geochemical analysis furthermore suggest that the clay-rich intervals are similar to sapropelic deposits.<br />
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On the Marion Plateau, trends in oxygen and carbon isotopes were obtained by measuring Cibicidoides spp foraminifers. Moreover, carbonate content was reconstructed using a chemical method (coulometer). Results show that the mid Miocene cooling step profoundly affected this system: a major drop in accumulation rates of carbonates occurs precisely at 13.8 Ma, around the time of the East Antarctic ice sheet formation. Moreover, sedimentation changes occurred at that time, carbonate fragments coming from neritic environments becoming less abundant, planktonic foraminifer content increasing and quartz and reworked glauconite being deposited. Conversely, a surprising result is that the major N12-N14 sea-level fall occurring around 11.5 Ma did not impact the accumulation of carbonates on the slope. This was unexpected since carbonate platform are very sensitive to sea-level changes. The model developed to explain that mass accumulation rates of carbonates diminished around 13.6 Ma (Mi3 Event) instead of 11.5 Ma (N12-N14 event), suggests that oceanic currents were controlling slope carbonate deposition on the Marion Plateau prior to the mid-Miocene, and that the mid Miocene event considerably increase their strength, hence reducing the amount of carbonate being deposited on slope sites. Moreover, by combining results from deep-sea oxygen isotopes with sea-level estimates based on coastal onlaps made during Leg 194, we constrain the amplitude of the N12-N14 sea-level fall to 90 meters. When integrating isotopic results from this study, this amplitude is lowered to 70 meters.<br />
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A general conclusion of this work is that the mid Miocene climatic shift did impact carbonate systems, at least at the two locations studied. However, the nature of this response was highly dependant on the regional settings, in particular the presence of land mass (Malta) and the absence of a barrier to shelter from the effects of open ocean (Marion Plateau).
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Att investera i toppen av en högkonjunktur : Ett fenomen i svensk börshistoria / To invest at the top of an economic boom : A phenomenon in the Swedish stock market historyWennerström, Carl-Ludvig, Bäckdahl, Dennis January 2008 (has links)
Bakgrund: Åren 86-97 kännetecknas som en period med flera stora reformer och en svensk konjunktur som nådde sin botten med tre år i följd av negativ BNP-tillväxt. Påtagligt var även reaktionen från Stockholmsbörsen som i samband med lågkonjunkturen upplevde en kraftig nedgång. Vad drev då denna avkastningsutveckling, vinsterna eller värderingarna av dessa? Hur såg sambandet ut mellan konjunktur, bolagsvinster, vinstvärderingar och börsutveckling för perioden? Syfte: Syftet med denna uppsats, på uppdrag av Melker Schörling AB, är att studera avkastningsutveckling, bolagsvinster och P/E-multiplar över en konjunkturcykel för att analysera till vilken grad multipelexpansion/kontraktion kontra vinsttillväxt drivit avkastningen för olika branscher på Stockholmsbörsen. I ett andra skede utreds huruvida prognoser för P/E-tal och branschvinster på Stockholmsbörsen korrelerat med konjunkturen samt även hur EBITDA- och vinstmarginaler inverkat på aktievärderingar under tidsperioden. Utifrån studiens resultat kommer eventuella lärdomar kopplas till dagens konjunkturella situation. Genomförande: Insamlat datamaterial i form av siffror och nyckeltal utgår från Affärsvärldens tidsskrifter och årsböcker med början 1986 och slut 1997. Utifrån dessa har, för studien, relevanta beräkningar dessutom gjorts. Resultat: Studien av Stockholmsbörsen 86-97, där handelsbranschen genomled konjunkturnedgången bäst, visar inte på att konjunkturen spelar roll för avkastningsutvecklingen. Vinstprognoserna drev avkastningen under lågkonjunkturen medan vinstvärderingarna dämpade nedgången. Genomgående ökade vinstvärderingarna under lågkonjunkturen till följd av att vinstprognoserna föll mer än kursen. Studien visar på att dessa ökade vinstvärderingar innehöll överskattade vinstförväntningar. Innan börsnedgången befann sig P/E-talen på relativt låga nivåer och när utväxlingen i samband med lågkonjunkturens slut skedde var P/E-talen höga, vilket ifrågasätter huruvida P/E-talet egentligen är representativt under en lågkonjunktur samt dess förmåga att indikera på risk. Prognostiserat P/E-tal korrelerar väl med faktiskt P/E-tal men det faktiska fluktuerar i större grad. Marginalerna, som korrelerar negativt med vinstvärderingarna, uppvisar en laggningseffekt gentemot omsättningen. / Background: The years 86-97 are characterized as a period with many big reformations when the Swedish economy reached its bottom with three years in a row with negative GDP. The reaction from the Swedish stock market was substantial and Stockholmsbörsen went through a heavy bearish period. What was it that drove this stock return, the expected earnings or the valuation of them? What was the connection between the business cycle, earnings, valuations and stock return for this particular period? Aim: The aim of the thesis, on behalf of Melker Schörling AB, is to study stock return, company earnings and price-earnings ratios during a business cycle in order to analyse to what extent multiple expansion/contraction versus earnings growth have driven stock return for the different branches on Stockholmsbörsen. In a second stage we observe how estimates of branches’ price-earnings ratios and earnings correlate with the business cycle and what impact EBITDA and pre-tax profit margin have on valuation during the period. Based on the result of the thesis, contingent knowledge will be related to today’s economic situation. Completion: The data, consisting of figures and ratios, is collected from magazines and yearbooks of Affärsvärlden starting 1986 and ending 1997. With the help of these, relevant calculations have been made. Result: This study of Stockholmsbörsen during the years 86-97, where the consumer-goods index had the best performance, shows that the business cycle has no impact on the stock return. The earnings estimates drove the stock return during the economic slump of 91-93 while the valuations tempered the fall. Through the economic slump the valuations became higher due to the fact that the earnings estimates fell more than the stock return. The study also shows that the increased valuations consisted of overestimated earnings estimates. Before the stock market fell the price-earnings ratios were at relatively low levels and when bull period begun in the end of the economic slump the ratios were high. This fact questions whether the price-earnings ratio is representative during an economic slump and if the ratio indicates risk accurately. Forward PE correlates positively with current PE, but the current PE is more volatile. Margins, which correlate negatively with valuations, indicate a lagging effect towards sales growth.
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Carbon and nitrogen cycling in permeable continental shelf sediments and porewater solute exchange across the sediment-water interfaceRao, Alexandra Mina Fernandes 17 November 2006 (has links)
Continental margin sediments play an important role in marine biogeochemical cycles, partly due to high primary production rates and efficient export of organic matter to sediments in margin environments. This thesis presents studies of solute exchange in fine-grained sediments representative of slope and rise environments, and carbon and nitrogen cycling in sandy sediments dominant in continental shelves worldwide. Results of these studies advance understanding of the role of benthic processes on marine ecosystems.
In fine-grained sediments, solute exchange by diffusion, biological mixing and bioirrigation can be quantified using in situ flux chambers with inert tracer additions. Mechanistic models of chamber tracer transport across the seabed indicate that in organic-rich sediments, bioirrigation and mixing dominate over a wide range of bottom water oxygen levels, reflecting the patchiness and versatility of benthic macrofaunal communities. Positive correlations between benthic oxygen and tracer fluxes appear site-specific. Reliable chamber volume estimates derived from mechanistic models reveal that empirical fits to chamber tracer datasets may overestimate chamber volume and benthic solute fluxes.
The biogeochemistry of sandy, highly permeable sediments that dominate continental shelves is largely unknown because of the difficulty in sampling and studying them under natural conditions. Novel sediment reactors were developed and used to mimic in situ porewater advection and natural sedimentary conditions. Compositional changes of natural seawater, with and without the addition of
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Att investera i toppen av en högkonjunktur : Ett fenomen i svensk börshistoria / To invest at the top of an economic boom : A phenomenon in the Swedish stock market historyWennerström, Carl-Ludvig, Bäckdahl, Dennis January 2008 (has links)
<p>Bakgrund: Åren 86-97 kännetecknas som en period med flera stora reformer och en svensk konjunktur som nådde sin botten med tre år i följd av negativ BNP-tillväxt. Påtagligt var även reaktionen från Stockholmsbörsen som i samband med lågkonjunkturen upplevde en kraftig nedgång. Vad drev då denna avkastningsutveckling, vinsterna eller värderingarna av dessa? Hur såg sambandet ut mellan konjunktur, bolagsvinster, vinstvärderingar och börsutveckling för perioden?</p><p>Syfte: Syftet med denna uppsats, på uppdrag av Melker Schörling AB, är att studera avkastningsutveckling, bolagsvinster och P/E-multiplar över en konjunkturcykel för att analysera till vilken grad multipelexpansion/kontraktion kontra vinsttillväxt drivit avkastningen för olika branscher på Stockholmsbörsen.</p><p>I ett andra skede utreds huruvida prognoser för P/E-tal och branschvinster på Stockholmsbörsen korrelerat med konjunkturen samt även hur EBITDA- och vinstmarginaler inverkat på aktievärderingar under tidsperioden. Utifrån studiens resultat kommer eventuella lärdomar kopplas till dagens konjunkturella situation.</p><p>Genomförande: Insamlat datamaterial i form av siffror och nyckeltal utgår från Affärsvärldens tidsskrifter och årsböcker med början 1986 och slut 1997. Utifrån dessa har, för studien, relevanta beräkningar dessutom gjorts.</p><p>Resultat: Studien av Stockholmsbörsen 86-97, där handelsbranschen genomled konjunkturnedgången bäst, visar inte på att konjunkturen spelar roll för avkastningsutvecklingen. Vinstprognoserna drev avkastningen under lågkonjunkturen medan vinstvärderingarna dämpade nedgången. Genomgående ökade vinstvärderingarna under lågkonjunkturen till följd av att vinstprognoserna föll mer än kursen. Studien visar på att dessa ökade vinstvärderingar innehöll överskattade vinstförväntningar. Innan börsnedgången befann sig P/E-talen på relativt låga nivåer och när utväxlingen i samband med lågkonjunkturens slut skedde var P/E-talen höga, vilket ifrågasätter huruvida P/E-talet egentligen är representativt under en lågkonjunktur samt dess förmåga att indikera på risk. Prognostiserat P/E-tal korrelerar väl med faktiskt P/E-tal men det faktiska fluktuerar i större grad. Marginalerna, som korrelerar negativt med vinstvärderingarna, uppvisar en laggningseffekt gentemot omsättningen.</p> / <p>Background: The years 86-97 are characterized as a period with many big reformations when the Swedish economy reached its bottom with three years in a row with negative GDP. The reaction from the Swedish stock market was substantial and Stockholmsbörsen went through a heavy bearish period. What was it that drove this stock return, the expected earnings or the valuation of them? What was the connection between the business cycle, earnings, valuations and stock return for this particular period?</p><p>Aim: The aim of the thesis, on behalf of Melker Schörling AB, is to study stock return, company earnings and price-earnings ratios during a business cycle in order to analyse to what extent multiple expansion/contraction versus earnings growth have driven stock return for the different branches on Stockholmsbörsen.</p><p>In a second stage we observe how estimates of branches’ price-earnings ratios and earnings correlate with the business cycle and what impact EBITDA and pre-tax profit margin have on valuation during the period. Based on the result of the thesis, contingent knowledge will be related to today’s economic situation.</p><p>Completion: The data, consisting of figures and ratios, is collected from magazines and yearbooks of Affärsvärlden starting 1986 and ending 1997. With the help of these, relevant calculations have been made.</p><p>Result: This study of Stockholmsbörsen during the years 86-97, where the consumer-goods index had the best performance, shows that the business cycle has no impact on the stock return. The earnings estimates drove the stock return during the economic slump of 91-93 while the valuations tempered the fall. Through the economic slump the valuations became higher due to the fact that the earnings estimates fell more than the stock return. The study also shows that the increased valuations consisted of overestimated earnings estimates. Before the stock market fell the price-earnings ratios were at relatively low levels and when bull period begun in the end of the economic slump the ratios were high. This fact questions whether the price-earnings ratio is representative during an economic slump and if the ratio indicates risk accurately. Forward PE correlates positively with current PE, but the current PE is more volatile. Margins, which correlate negatively with valuations, indicate a lagging effect towards sales growth.</p>
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Zone d'attente pour personnes en instance : une ethnographie de la détention frontalière en FranceMakaremi, Chowra 01 1900 (has links)
L’ethnographie de la détention frontalière en France se penche sur le phénomène des migrations transnationales et sur le gouvernement des frontières qui y répond, à travers des pratiques d’enfermement et d’expulsion des étrangers dans une « zone d’attente » aéroportuaire. La construction des camps d’étrangers, dont relève ce terrain, témoigne de nouvelles distributions du pouvoir qui passent par l’accès à la mobilité. L’étude empirique d’une forme particulière de ce contrôle est ainsi le point de départ d’une réflexion plus large sur ce régime de gouvernement, qui dessine une autre topographie politique de la globalisation.
L’enquête nous invite à comprendre les pratiques par lesquelles les gouvernements démocratiques administrent des populations non-citoyennes, et la façon dont ces modalités de prise en charge et de surveillance opèrent une reconfiguration des frontières physiques, morales et politiques. L’ethnographie s’interroge sur l’expérience quotidienne de ceux qui sont les sujets de ces régimes juridiques et humanitaires croisés.
Le confinement des étrangers entrecroise plusieurs dimensions, qui organisent la recherche : la construction d’un enfermement humanitaire, et les usages institutionnels et militants de différents régimes de droits qui y sont en jeu; les pratiques de prise en charge de populations identifiées comme vulnérables; les reconfigurations de la frontière à travers de nouvelles formes réticulaires et zonales; et enfin, l’expérience de circulation que dessinent les archipels de surveillance, et les pratiques de gestion différentielle des mobilités dont participent les zones d’attente. / This ethnographic study of border detention in France investigates how, in response to trends in transnational migration, borders are governed through practices such as the confinement and deportation of foreign migrants. In particular, the increasing prominence of camps or other restricted areas in which migrants or illegal aliens are held for varying lengths of time highlight a new distribution of power, defined by access to mobility. Focusing on a specific form of control – the “waiting zone” at an airport's borders – this empirical study offers an in depth meditation on this power dynamic, which reflects, in itself, another political topography of globalization.
The research investigates how democratic governments manage non citizen populations, and examines the ways in which the types of restriction and surveillance brought to bear on these people reconfigure physical, moral and political boundaries. The ethnographic components of the study seek to explore the everyday experience of the people who become subject to these tangled legal and humanitarian procedures.
The research interweaves several key issues which shape policy on border detention: confinement, albeit in a humanitarian form, constructed through judicial activism and the administrative application of different standards of rights for various alien populations; the conflation of humanitarian care and control for populations identified as vulnerable; the redrawing of frontiers through networks and zones; and, lastly, the experience of mobility produced by the differential management of movement within the modern archipelagos of surveillance, of which waiting zones are part.
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Structure, stratigraphy, and U-Pb zircon-titanite geochronology of the Aley carbonatite complex, northeast British Columbia: Evidence for Antler-aged orogenesis in the Foreland Belt of the Canadian CordilleraMcLeish, Duncan Forbes 26 April 2013 (has links)
The tectonic significance and age of carbonatite intrusions in the western Foreland Belt of the Canadian Cordillera are poorly constrained. Recent 1:5,000 scale field mapping of one of these carbonatite intrusions, the Aley carbonatite (NTS 94 B/5), has demonstrated that it was emplaced as a syn-kinematic sill, coeval with a major nappe-forming tectonic event. Determining the age of the Aley carbonatite therefore provides a means of directly dating tectonism related to carbonatite magmatism. A U-Pb titanite age of 365.9 +/- 2.1 Ma was obtained from the Ospika pipe, an ultramafic diatreme spatially and genetically related to the carbonatite. We interpret the Late Devonian age of the Ospika pipe to be the minimum possible age of the carbonatite and syn-magmatic nappe-forming tectonic event. The maximum possible age of the carbonatite is constrained by the Early Devonian age of the Road River Group (ca. 410 Ma), the youngest strata intruded by carbonatite dykes and involved in the nappe forming event. Our dating results for the Aley carbonatite closely correlate with U-Pb zircon and perovskite ages obtained for the Ice River carbonatite complex in the western Foreland Belt of the southern Canadian Cordillera, and support the interpretation of carbonatite intrusions of the western Foreland Belt as genetically linked components of an alkaline-carbonatitic magmatic province. Structural, stratigraphic, and geochronological data from the Aley area indicate that deformation was similar in style to, and coeval with, structures attributable to the Antler Orogeny, and are consistent with the Antler orogen having extended the length of Cordilleran margin from the southern United States to Alaska. Deformed alkaline-carbonatite intrusions that characterize continental suture zones in Africa and Tibet may provide an analogue for the Aley carbonatite and correlative alkaline-carbonatite complexes in the western Foreland Belt. / Graduate / 0372 / mcleish@uvic.ca
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Zone d'attente pour personnes en instance : une ethnographie de la détention frontalière en FranceMakaremi, Chowra 01 1900 (has links)
No description available.
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Structure profonde de la marge Nord-Ouest Africaine / Deep crustal structure of the North-West African marginBiari, Youssef 04 December 2015 (has links)
La marge NE Américaine est une des marges les mieux étudiées au monde, elle a fait l’objet de plusieurs études géophysiques. En comparaison, la marge africaine reste peu étudiée car uniquement deux campagnes océanographiques y ont été menées : la campagne Sismar (2001) au large de la Meseta et la campagne Dakhla (2002) au large du Sahara. La structure profonde de la marge canadienne est connue grâce aux profils de sismique grand-angle SMART-1, 2 et 3. Le premier objectif du projet MIRROR était d’acquérir des profils combinant sismique grand-angle et sismique réflexion sur un segment homologue au profil SMART-1. La comparaison entre les segments homologues de ces deux marges ayant pour but de mieux comprendre le mode d’ouverture de l'océan Atlantique Central. Une comparaison entre les modèles Sismar, Dakhla et Mirror montre que la croûte continentale est plus épaisse au nord et s'amincit vers le sud. La largeur de la zone de transition est plus étroite au sud et les profils Sismar sont localisés sur un bassin sédimentaire posé sur une croûte continentale très amincie. La comparaison avec la marge homologue montre que l'épaisseur, la structure de la croûte continentale et la zone d'amincissement sont très semblables. Par contre, il existe une zone de manteau exhumé et serpentinisé sur le profil Canadien qui n'a pas d’homologue sur la marge africaine. De plus, l'épaisseur de la croûte océanique est différente avec 8 km sur la côte africaine et seulement 3-4 km sur la marge canadienne. Plusieurs hypothèses ont été proposées pour expliquer cette différence (a) une différence d’âge entre les deux croûtes (b) un épaississement lié au passage du point chaud des Canaries (c) une accrétion asymétrique. / The NE American margin represents one of the best studied margins in the world, it was the subject of several scientific programs. In comparison, the conjugate NW African margin remains fairly unknown, only two deep seismic cruises were acquired: the SISMAR cruise (2001) offshore the Meseta and the DAKHLA cruise (2002) offshore the Sahara. The deep structure of the Canadian margin is known due to the SMART wide-angle seismic profiles 1, 2 and 3. The first objective of the MIRROR project was to acquire combined wide-angle and deep reflection seismic data offshore a segment conjugate to the SMART-1 profile. The comparison between the homologous segments of these two margins aimed to better understand the opening mechanism of the Central Atlantic Ocean. A comparison between Sismar, Dakhla and Mirror models shows that the continental crust is thicker in the north and thins toward the south. The width of the transition zone is narrower south and Sismar profiles are located on a sedimentary basin placed on a very thinned continental crust. Comparing the Mirror profile with that of the Canadian conjugate margin (Smart 1) shows that the thickness, the structure of the continental crust and the thinning is very similar. However, zones of exhumed and serpentinized mantle were imaged along the Canadian profile that have no conjugate on the African margin. Moreover, the thickness of the oceanic crust is variable with 8 km on the African side and only 3-4 km on the Canadian margin. Several hypotheses have been proposed to explain this difference (a) an age difference between the two types of crust (b) thickening associated with the passage of the Canary hotspot (c) an asymmetric accretion or (d) an accretion at slow to ultra-slow speading centers.
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Preços de transferência e margens de lucro alternativasBalsimelli, Felipe Cerrutti 10 October 2016 (has links)
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Previous issue date: 2016-10-10 / The present study analyzes the Brazilian transfer pricing rules, regarding the possible use of advanced price agreements (APAs). The Brazilian APAs has grounds on the proper Brazilian legislation: Law No. 9430/1996, Normative Ruling No. 1312/2012, Ordinance No. 222/2008 and other applicable Brazilian rules. This study presents the APAs as viable instruments to achieve the arm’s length principle and to avoid the distortions caused by the Brazilian fixed margin methods: PRL, CPL, CAP, PVA and PVV, in spite of its practicability. Although not expressly set forth in the Brazilian Federal Constitution of 1988 (FC/88), nor in the domestic Brazilian transfer pricing legislation (which was inspired in the OECD model), the arm’s length principle is presented as a proper 'Brazilian principle'. In this sense, the Brazilian arm’s length principle is presented within the context of other effective Brazilian tax principles expressly provided in the FC/88: mainly the constitutional principles of equality, contributive capacity, legality and mandatorily administrative act. According to the arm’s length principle, based on which transactions between related parties should equalized to the ones carried out by independent parties, the Brazilian transfer pricing rules are defended as constitutional rules, provided the alternative margins are feasible from a legal and practical perspective. This study concludes that the Brazilian APAs are legal and practical instruments to avoid administrative and judicial disputes, as well as to achieve the transfer pricing adjustments at real arm’s length conditions. It also exams the nature of Brazilian APAs (formal consultations) and provides a practice guidance for its application, as well as a critic overview of the applicable legislation. / O presente estudo examina as regras brasileiras de preços de transferência, no que diz respeito à possibilidade de utilização de acordos de preços antecipados (APAs). Os APAs brasileiros têm fundamento na própria legislação brasileira: Lei nº 9.430/1996, Instrução Normativa nº 1.312/2012, Portaria nº 222/2008 e outros normativos brasileiros aplicáveis. O estudo apresenta os APAs como instrumentos viáveis para se alcançar o princípio arm’s length e para afastar distorções causadas pelos métodos de margens fixas: PRL, CPL, CAP, PVA e PVV, em que pese sua praticabilidade. Embora não expressamente previsto pela Constituição Federal de 1988 (CF/88), nem pela legislação interna brasileira de preços de transferência (inspirada no modelo OCDE), o princípio arm’s length é apresentado como um 'princípio brasileiro'. Para tanto, o princípio arm’s length brasileiro é examinado no contexto dos princípios brasileiros expressamente indicados na CF/88: em especial os princípios de isonomia, capacidade contributiva, legalidade e vinculação do ato administrativo. De acordo com o princípio arm’s length, segundo o qual as operações entre partes relacionadas devem ser equiparadas a operações entre partes independentes, as regras brasileiras de preços de transferência são normas constitucionais, desde que a utilização de margens alternativas sejam aplicáveis sob uma perspectiva legal e prática. O estudo conclui que os APAs brasileiros são instrumentos legais e práticos aptos a evitar disputas administrativas e judiciais, bem como para viabilizar ajustes de preços de transferência em condições arm’s length. O estudo examina ainda a natureza dos APAs brasileiros (de consulta formal) e apresenta um guia prático para sua aplicação, além de uma crítica à legislação sobre o tema.
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