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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.
341

Neotectonic evolution of the Serrania Del Interior range and Monagas fold and thrust belt, Eastern Venezuela : Morphotectonics, Seismic Profiles Analyses and Paleomagnetism / Evolution Néotectonique de la Serranía Del Interior et de la ceinture plissée de Monagas, Nord-Est du Venezuela : Morphotectonique, Interprétation Sismique et Paléomagnétisme

Fajardo, Atiria 19 November 2015 (has links)
La convergence oblique entre les plaques Caraïbes et Amérique du Sud à partir de l'Oligocène a conduit à la formation de la cordillère « Serranía del Interior » (SDI) et de son avant pays au sud (bassin de Maturín) et la ceinture plissée de Monagas. D’abord transpressif (direction NW-SE), le déplacement entre les deux plaques devient à compter de ~12 Ma principalement une translation O-E qui s’accommode principalement sur la faille d’El Pilar. Cependant, des indices de compression active ont été identifiés à la terminaison de la faille d'Urica dans la chaine plissée de Monagas. Pour discuter des mécanismes de cette déformation compressive actuelle, nous avons mis en œuvre une interprétation sismique (2D et 3D), une étude géomorphologique et une étude paléomagnétique. Depuis le front sud de la SDI dans la chaîne plissée de Monagas, l'interprétation sismique et l’analyse géomorphologique se sont concentrées sur les chevauchements de San Félix, Tarragona, Punta de Mata, Jusepín et Amarilis. Deux discordances miocènes (Mid-Miocene Unconformity (MMU) de ~10 Ma et Late Miocene Unconformity (LMU) de ~5,3 Ma) ont été cartographiées sur la sismique. En s’appuyant sur la LMU, il a été calculé à l’aplomb de ces accidents un taux de soulèvement plio-pléistocène de ~0,4 mm/a. Invisibles sur la sismique, des déformations ont aussi été observées en surface sur ces accidents (des terrasses fluviatiles basculées, plissées et faillées et des anomalies de drainage). Datées par des méthodes cosmonucléides (10Be et 26Al), l’âge des terrasses alluviales déformées sont compris entre ~90 ka sur le chevauchement de Tarragona et ~15 ka dans la zone de Punta de Mata. Un taux minimal de soulèvement pléistocène terminal à l’aplomb des chevauchements a été calculé entre 0,1 et 0,6 mm/a. Cette gamme de vitesse recouvre celle renvoyée par la LMU et montre que la déformation n'a pas varié significativement pendant les derniers 5,3 Ma. Ces observations montrent que les chevauchements de Tarragona, Pirital El Furrial et d’autres plus jeunes développés dans la formation Carapita restent actifs. Cette déformation superficielle s’estompe rapidement vers l’est près de la ville Maturín. Nous interprétons cette déformation comme liée au jeu récent de la faille d'Urica qui se termine au sud en queue de cheval. La faille d’Urica accommoderait donc une partie du déplacement entre plaques Caraïbe et Amérique du Sud. Une étude paléomagnétique a été réalisée dans les blocs de Caripe et Bergatín au sein de la SDI où 27 localités ont été échantillonnées dans les sédiments du Crétacé au Paléocène. Une observation clé de cette étude a été la mise en évidence d'une composante paléomagnétique stable déviée vers le Nord Est avec des polarités normale et inverse. Les analyses statistiques de ces composantes indiquent une acquisition postérieure au plissement de la SDI (< ~12 Ma). La déclinaison moyenne dans les blocs de Caripe et de Bergatín indique une rotation horaire de R=37º±4 º autour d’un axe vertical. Le taux de rotation post-Miocene moyen avoisine ~3.7º/Ma et reste probablement actif. Nous proposons de rattacher cette rotation horaire à un système de failles type "Riedel" (Urica et San Francisco) en relation avec la faille d’El Pilar. / In Northeastern Venezuela, the tectonic provinces of the Serranía Del Interior thrust belt (high hills), the Monagas Thrust belt (foothills) and the Maturín foreland basin formed as a result of the oblique convergence between the Caribbean and South American plates since the Oligocene. GPS data show that post 12 My wrenching component between the plates is accommodated predominantly by the E-W strike-slip El Pilar Fault. However, evidence of active compression has been identified in the southern limit of the NW-SE dextral Urica Fault, specifically, in the Monagas Fold and Thrust Belt. In order to constrain the neotectonics of this area, this thesis presents a combined approach, which includes geomorphological study, seismic and paleomagnetism. In the Monagas Fold and Thrust Belt, the geomorphological study and the seismic interpretation were focused on five zones. From the foothills to the deformation front, these zones are: San Felix, Tarragona, Punta de Mata, Jusepín and Amarilis. These areas show surface deformations such as topographic uplifts, tilted terraces, folded terraces, faulted terraces, and drainage anomalies. The dating of the river terraces through 10Be and 26Al methods indicates that these terraces formed in the Late Pleistocene. The oldest terrace located in the Tarragona zone has a maximum exposure age of ~90 ky and the youngest located in the Punta de Mata zone of ~15 ky. From this dating, a minimum vertical deformation rate between ~0.6-0.1 mm/y was calculated for this area. Using the seismic interpretation of a 3D block, the surfaces of two unconformities (MMU and LMU) have been mapped. The age obtained for the LMU (~5.3 My), yield a Plio-Pleistocene uplift rate between ~0.3-0.4 mm/y, which is close to the vertical deformation rate calculated from the terraces dated. These similar rates seem to indicate that the deformation rate in the MFTB has not changed significantly for the last 5.3 My. The deformed surfaces observed in the field and in DEM images coincide vertically with the deep structures interpreted in the seismic lines. I propose that the deformation on the surface is linked to the Tarragona, Pirital, Furrial thrusts and the Amarilis Backthrust activity and to the youngest thrusts developed in the Carapita Formation. However, this surface deformation dies out near the city of Maturín, therefore, the neotectonic deformation is inferred to be caused by local tectonics. I propose that this local compressive deformation could have been generated by a horsetail termination in the southern limit of the Urica Fault which reactivated the oldest thrusts (Tarragona and Pirital thrusts) and deformed the post-Middle Miocene units until reaching the surface. In the zones where the El Pilar Fault mainly accommodates the wrenching component, block rotation is likely. For that reason, a paleomagnetic study was conducted in the Caripe and Bergatín blocks of the Serranía Del Interior where 27 sites were sampled in Cretaceous to Paleocene sediments. Statistics analyses of the components yield a negative bedding-tilt test, indicating that this component was acquired post ~12 My after the folding process in the Serranía del interior. The average declination indicates a clockwise block rotation of R = 37º ± 4º and a post-Middle Miocene rotation rate of ~3.7º/My in both the Caripe and Bergatín blocks. This rotation rate is probably still active. I propose to relate the regional clockwise rotation to the development of a synthetic Riedel shear system formed by the El Pilar Fault (master regional fault) and by the Urica and San Francisco synthetic Riedel shears.
342

Exocomets at large orbital radii and their inward transport in debris discs

Marino Estay, Sebastián January 2018 (has links)
Planetary systems are not only composed of planets, but also of km-sized rocky and icy bodies that are confined within belts similar to the Asteroid and Kuiper belt in the Solar System. Mutual collisions within these belts grind down solids producing dust and giving rise to debris discs. Primitive asteroids and comets likely played a major role in the emergence of life on Earth through their delivery of volatiles early in the lifetime of our planet. Cometary impacts, therefore, could be a necessary condition for the emergence of life in exoplanets and the study of debris discs essential to determine the ubiquity of such phenomenon. Moreover, exocometary discs provide a unique window into the origins and outer regions of planetary systems as comets do within our Solar System. Initially, in Chapter 1 I present an overview of the study of exoplanetary systems, focusing on debris discs. I discuss the basics of planet formation, its connection with debris discs, and how these evolve and interact with planets. I also describe how we observe these discs and probe their volatile component that is locked inside exocomets, and some evidence supporting the idea of exocomets venturing into the inner regions of planetary systems. Then, in Chapters 2, 3, 4 and 5 I present new ALMA observations of the systems HD 181327, η Corvi, the multiplanet system 61 Vir and HD 107146, which host debris discs. In the first two, I highlight the derivation of the density structure of their discs and the detection of volatiles being released by exocomets; while in the third and fourth I compare the observations with simulations, which I use to set constraints on the underlying planetesimal distribution and mass and orbital distance of unseen planets. Finally, in Chapter 6 I present result obtained from N-body simulations to study the process of inward transport of comets by a multiplanetary system and how these can deliver material to inner planets and explain the frequently observed exozodiacal dust. To conclude, in Chapter 7 I summarise the results and conclusions of this dissertation and discuss ongoing and future work.
343

Análises estatísticas de Cloudina spp. no sul da faixa Paraguai e Namíbia. E suas implicações filogenéticas e evolutivas. / not available

Strikis, Pedro Carlos 07 December 2017 (has links)
No presente trabalho foram analisadas amostras de mão (carbonatos) provenientes da Formação Tagatiya Guazú, Grupo Itapucumí Paraguai (extremo sul da Faixa Dobrada Vallemí) e da Formação Tamengo Grupo Corumbá Brasil (Sul da Faixa Paraguai) todas do final do Ediacarano e lâminas delgadas confeccionadas a partir destas amostras e de outros carbonatos da Formação Tamengo e também provenientes da Formação Kuibis, Namíbia. Todas foram fotografadas e os diâmetros dos funis das espécies de Cloudina presentes medidos (tanto das amostras de mão quanto das lâminas delgadas). As medidas obtidas foram analisadas por técnicas estatísticas básicas e testes de normalidade, e não paramétricos (teste de Mann-Whitney, Kruskal-Wallis) e também teste de Kolmogorov-Smirnov para se estabelecer possível semelhança entre as amostras, também se efetuou análises exploratórias de Escalamento Multidimensional não Métrico e Análise de Agrupamento. Os resultados obtidos permitiram estabelecer a presença de três espécies de Cloudina, sendo uma delas nova (C. lucianoi, C. riemkeae e C. latilabrum n. sp.). Também foi possível estabelecer relações ecológicas onde se concluiu que viveram em ambientes semelhantes, juntas temporalmente. Detectou-se a presença de C. riemkeae partir da comparação com as mensurações efetuadas no material proveniente da Namíbia e não foi detectada a presença de C. hartmannae na Faixa Paraguai. Propôs-se uma filoginia para as espécies presentes na Faixa Paraguai e o processo de especiação que teria levado a filogenia proposta. Amostra da Formação Tagatiya Guazú foi submetida a técnica de microtomografia de raio-X. A microtomografia de raio-X permitiu o estabelecimento de um novo organismo ou dubiofossil para o Final do Ediacarano, Virgula itapucumense interpretado como possuindo corpo mole, segmentado que foi considerado como engenheiro de ecossistema pela sua forma de vida, infauna provavelmente se alimentava de tapetes bacterianos, ou também pelotas de fezes de organsmos infaunais. / In the present work were analyzed hand samples (carbonates), as well as thin sections from Tagatiya Guazú Formation, Itapucumí Group, Paraguay (Southern Vallemí Fold Belt) and from Tamengo Formation Group Corumbá, Brazil (Southern Paraguay Belt) from the end of Ediacaran period, and thin slides obtained from these samples and others carbonates from the same formations as well as from Kuibis Formation Namibia. All samples were photographed and the diameter of the funnels of species from Cloudina were measured (from hand samples and thin slides). The measurements were analyzed by simple statistics methods in order to determine mean, standard deviation and other parameters, normality tests were used, and nonparametric tests performed (Mann-Whitney, Kruskal-Wallis) and also the test of Kolmogorov- Smirnov, exploratory technics were applied in order to find any possible similarity between samples. Exploratory techniques NMMDS and Classical Clustering were applied to find affinities between samples. The results of statistical analyses led to the establishment of three species of Cloudina: C. riemkeae, C. lucianoi and C. latilabrum n. sp. in the Paraguay and Vallemí Belt. Also, ecological relations between these species living in the same habitat at the same time at the end of Ediacaran period were inferred. The presence of C. riemkeae was inferred by comparing the measurements of this species present in slides from Namibia with those slides and hand samples from Paraguay Belt. The presence of C. hartmannae was not detected in the Paraguay Belt. A phylogeny for the species of Cloudina present in the Paraguay Belt was proposed as well as a process of speciation that led to this phylogeny. A sample from Tagatiya Guazú was used in X-Ray microtomography. The results of X-Ray Microtomography led to the establishment of a new fossil organism or at least a dubiofossil at the end of Ediacaran period that has soft body and was segmented named Virgula itapucumense, that was considered an ecosystem engineer due to its life mode, infaunal and feeding in bacterial mat, or feces pellets of infaunal organisms.
344

Determinants of adherence in patients on ART on the Copper Belt Province in Zambia

Chisa, Sume Percival 03 1900 (has links)
Thesis (MPhil (Industrial Psychology. Africa Centre for HIV/AIDS Management))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: Chronic drug therapy has been fraught with many issues such as adherence, drug intolerance, long-term toxicity and resistance. In HIV/AIDS care, adherence is a major problem due to the fact that for success of the therapy, adherence must be in the region of ninety five percent. If this is not maintained the virus begins to mutate and resistant moieties appear, and this in turn leads to failure of the therapy. This high level of adherence is very difficult to maintain especially in patients who begin antiretroviral therapy (ART) for various reasons such as persuasion by health workers and family, and not due to their own conviction. They usually tend not to adhere to the therapy when symptoms resolve and they start feeling better. There are a number of factors that promote adherence and these are incorporated into HIV care for the programme to succeed. The research was intended to explore and describe factors causing patients to default ART on the Copper belt in Ndola at Ndola Central Hospital and to ultimately propose appropriate interventions to ensure improved return rates of patients on ART. Qualitative tools i.e. interviews and focus group discussions respectively were used, taking into account ethical considerations and data collected was then analyzed. Factors causing patients to default on ART were found to be poor social economic background, inadequate finance, unavailability of food, poor or little understanding of instructions, poor quality of counseling or low literacy levels, high pill burden, unpalatability of drugs and patient readiness to life time commitment to taking ARVS. / AFRIKAANSE OPSOMMING: Chroniese medisyneterapie is gepaard gaande met vele kwessies soos trou bly, weerstandsgebrek aan medisyne, langtermyn toksisiteit en weerstand. In MIV/Vigs sorg, is trou bly 'n groot probleem weens die feit dat vir sukses in terapie moet dit oor vyf-en-negentig persent wees. As dit nie gehandhaaf word nie sal die virus begin verander en weerstand weestandbiedende gedeeltes sal verskyn, en dit op sy beurt lei tot die mislukking van die terapie. Hierdie hoë vlak van trou bly is baie moeilik om te handhaaf veral in pasiente wie antiretrovirale terapie (ART) vir verskeie redes begin het soos oorreeding deur gesondheids werkers en familie, en nie deur hul eie oortuiging nie. Hulle neig gewoonlik om die terapie te laat vaar wanneer simptome verminder en hulle begin beter voel. Daar is verskeie faktore wat trou bly bevorder en wat ingelyf word in MIV sorg om die program te laat slaag. Die doel van hierdie navorsing was om die faktore te beskryf wat veroorsaak dat pasiente op die Copperbelt in Ndola by Ndola Sentrale Hospitaal hul ART verpligtinge nie nakom nie en om uiteindelik geskikte intervensies voor te stel om verbeterde terugkeer koerse van pasiente op ART te verseker. Kwalitatiewe insrumente, dit is, onderhoude en fokusgroupe is gebruik, met in agneming etiese kwessies, en data is daarna geanaliseer.
345

Análises estatísticas de Cloudina spp. no sul da faixa Paraguai e Namíbia. E suas implicações filogenéticas e evolutivas. / not available

Pedro Carlos Strikis 07 December 2017 (has links)
No presente trabalho foram analisadas amostras de mão (carbonatos) provenientes da Formação Tagatiya Guazú, Grupo Itapucumí Paraguai (extremo sul da Faixa Dobrada Vallemí) e da Formação Tamengo Grupo Corumbá Brasil (Sul da Faixa Paraguai) todas do final do Ediacarano e lâminas delgadas confeccionadas a partir destas amostras e de outros carbonatos da Formação Tamengo e também provenientes da Formação Kuibis, Namíbia. Todas foram fotografadas e os diâmetros dos funis das espécies de Cloudina presentes medidos (tanto das amostras de mão quanto das lâminas delgadas). As medidas obtidas foram analisadas por técnicas estatísticas básicas e testes de normalidade, e não paramétricos (teste de Mann-Whitney, Kruskal-Wallis) e também teste de Kolmogorov-Smirnov para se estabelecer possível semelhança entre as amostras, também se efetuou análises exploratórias de Escalamento Multidimensional não Métrico e Análise de Agrupamento. Os resultados obtidos permitiram estabelecer a presença de três espécies de Cloudina, sendo uma delas nova (C. lucianoi, C. riemkeae e C. latilabrum n. sp.). Também foi possível estabelecer relações ecológicas onde se concluiu que viveram em ambientes semelhantes, juntas temporalmente. Detectou-se a presença de C. riemkeae partir da comparação com as mensurações efetuadas no material proveniente da Namíbia e não foi detectada a presença de C. hartmannae na Faixa Paraguai. Propôs-se uma filoginia para as espécies presentes na Faixa Paraguai e o processo de especiação que teria levado a filogenia proposta. Amostra da Formação Tagatiya Guazú foi submetida a técnica de microtomografia de raio-X. A microtomografia de raio-X permitiu o estabelecimento de um novo organismo ou dubiofossil para o Final do Ediacarano, Virgula itapucumense interpretado como possuindo corpo mole, segmentado que foi considerado como engenheiro de ecossistema pela sua forma de vida, infauna provavelmente se alimentava de tapetes bacterianos, ou também pelotas de fezes de organsmos infaunais. / In the present work were analyzed hand samples (carbonates), as well as thin sections from Tagatiya Guazú Formation, Itapucumí Group, Paraguay (Southern Vallemí Fold Belt) and from Tamengo Formation Group Corumbá, Brazil (Southern Paraguay Belt) from the end of Ediacaran period, and thin slides obtained from these samples and others carbonates from the same formations as well as from Kuibis Formation Namibia. All samples were photographed and the diameter of the funnels of species from Cloudina were measured (from hand samples and thin slides). The measurements were analyzed by simple statistics methods in order to determine mean, standard deviation and other parameters, normality tests were used, and nonparametric tests performed (Mann-Whitney, Kruskal-Wallis) and also the test of Kolmogorov- Smirnov, exploratory technics were applied in order to find any possible similarity between samples. Exploratory techniques NMMDS and Classical Clustering were applied to find affinities between samples. The results of statistical analyses led to the establishment of three species of Cloudina: C. riemkeae, C. lucianoi and C. latilabrum n. sp. in the Paraguay and Vallemí Belt. Also, ecological relations between these species living in the same habitat at the same time at the end of Ediacaran period were inferred. The presence of C. riemkeae was inferred by comparing the measurements of this species present in slides from Namibia with those slides and hand samples from Paraguay Belt. The presence of C. hartmannae was not detected in the Paraguay Belt. A phylogeny for the species of Cloudina present in the Paraguay Belt was proposed as well as a process of speciation that led to this phylogeny. A sample from Tagatiya Guazú was used in X-Ray microtomography. The results of X-Ray Microtomography led to the establishment of a new fossil organism or at least a dubiofossil at the end of Ediacaran period that has soft body and was segmented named Virgula itapucumense, that was considered an ecosystem engineer due to its life mode, infaunal and feeding in bacterial mat, or feces pellets of infaunal organisms.
346

Étude des propriétés élastiques des verres d’oxydes sous haute pression : implications structurales / Pressure induced structural transformations in glasses

Sonneville, Camille 10 July 2013 (has links)
Le comportement des verres sous pression, lié à leurs structures topologiques, est un enjeu majeur à la fois fondamental et appliqué. L’anomalie élastique de la silice à 2,5GPa est un phénomène connu et son existence est plus que probable dans le verre de GeO2. Il semblait alors légitime de questionner son existence dans des verres plus répandus de compositions chimiques complexes comme les verres alumino sodo silicatés. L’anomalie élastique a été étudiée in situ par Diffusion Brillouin et Raman pour le verre de GeO2 et trois verres alumino sodo silicaté de compositions chimiques : (Al2O3)X(Na2O)25−X(SiO2)75 où X=0, 6 et 12%. Il a été montré que l’existence de l’anomalie de compressibilité dans le domaine élastique n’était pas réduite qu’à la silice uniquement mais au contraire persistait sur un vaste domaine de compositions chimiques et semblait être liée à la présence d’anneaux à 6 tétraèdres. Au delà de la limite élastique, les modifications structurales à l’origine du phénomène de densification permanente ont été étudiées pour la silice, le verre de GeO2 et six verres d’alumino sodo silicatés (contenant X=0, 2, 6, 9, 12 et 16% d’Al2O3). Tout d’abord nous avons observé par diffusion Brillouin la disparition progressive de l’anomalie élastique de la silice avec la densification. Ce phénomène a été interprété en termes de transformations induites par la pression d’une forme amorphe basse densité (LDA) en une forme amorphe haute densité (HDA) : LDA → HDA. Des études in situ et ex situ par Diffusion Brillouin et Raman, Résonance Magnétique Nucléaire (RMN) et aussi de Spectroscopie d’Absorption des Rayons X proche du seuil (XANES) ont montré que les modifications structurales à l’origine de la densification permanente dépendaient grandement de la composition chimique. En particulier la présence de cation sodique semble favoriser les modifications à courte portée comme la formation d’espèces hautement coordonnées d’aluminium ou encore de silicium ainsi que la dépolymérisation du réseau. Au contraire les verres les plus riches en aluminium semblent montrer une densification plus proche structurellement de celle de la silice pure c’est à dire modifiant principalement l’ordre à moyenne distance avec diminution de l’angle inter-tétraèdre et de la taille des anneaux / The structural study of glasses under pressure is of fundamental interest in Physics, Earth Science and is technologically important for the comprehension of industrial material properties. The elastic anomaly at 2.5GPa in pure silica glass is a well known phenomenon and its existence is more than likely in GeO2 glass. In this work the persistence of the elastic anomaly in more complex and more widely glass compositions as sodium alumino silicate glasses was studied. The elastic anomaly was studied in situ in GeO2 and three sodium alumino silicate glasses by Brillouin and Raman scattering. The studied sodium alumino silicate glasses had the following compositions : (Al2O3)X(Na2O)25−X(SiO2)75 where X=0, 6 et 12% and is the molar percentage of Al2O3. The elastic anomaly was shown to persist in a broad domain of chemical compositions thus its existence is not reduced to pure silica glass. Its existence seems to be linked to the presence of 6 membered rings. Beyond the elastic limit, the structural modifications was studied in pure silica, GeO2 glass and sodium alumino silica glasses (with X=0, 2, 6, 9, 12 et 16% of Al2O3) in order to structurally better understand the densification phenomenon. Firstly the elastic anomaly was studied by Brillouin scattering experiments, was shown to progressively disappear with the densification. This progressive disappearance was interpreted in terms of a progressive structure induced transformation from a Low Density Amorphous form (LDA) into a High Density Amorphous form (HDA) : LDA → HDA. In situ and ex situ studies by Brillouin and Raman scattering, Nuclear Magnetic Resonance (NMR) and X-ray Absorption Near Edge Structure (XANES) showed that the pressure induced structural transformation was highly dependent of the glass chemical composition. For instance the presence of sodium cations promotes short range order modifications, such as formation of highly coordinated species (Al, Si) and network depolymerization. On the other hand, glasses with a high aluminum concentration show a densification process closer to that of pure silica glass, with mainly middle range order structural modifications such as a decrease of the inter-tetrahedral angle or ring size decrease
347

Controls on river and overbank processes in an aggradation-dominated system : Permo-Triassic Beaufort Group, South Africa

Gulliford, Alice Rachel January 2014 (has links)
The Permo-Triassic lower Beaufort Group fluvial deposits extend over 100s of kilometres within the Karoo Basin, South Africa. A detailed study of the depositional architecture and stacking patterns of sand bodies within a 900 m thick succession has enabled interpretation of the controls on ancient river channel and overbank processes. Facies include very fine- to medium-grained sandstone, intra-formational conglomerate, mudstone and palaeosols. Channel-belts are dominated by upper flow regime structures, consistent with a flashy to ephemeral fluvial system. The overbank deposits comprise splays interbedded with purple, green and grey mudstone; these floodplain colour changes signify water table fluctuations. A hierarchy of channel-related elements has been established that recognises beds, bedsets, storeys, channel-belts, complexes and complex sets. Each channel-belt may be single- or multi-storey, whereby one storey represents the complete cut and fill cycle of a single migrating river, comprising bar accretion elements and channel-abandonment fill. The abandonment fill elements often consist of heterolithic plugs of climbing ripple-laminated very fine-grained sandstone, or interbedded claystone with siltstone. The Beaufort channel-belts preserve either lateral- or downstream-accretion patterns, or a combination. Each belt has either a lenticular or tabular geometry, recognisable by an erosional base overlain by intra-formational conglomerate lag and barform deposits. Genetically related channel-belts cluster to form complexes, of which two broad styles have been identified: Type A) laterally and vertically stacked channel-belts, and Type B) sub-vertically stacked channel-belts. There is evidence of localised clustering of sub-vertically stacked channel-belts adjacent to extensive overbank mudstone deposits. The apparent lack of a well-defined ‘container’ surface with mappable margins, suggests that this stacked channel-belt architecture represents an avulsion complex rather than a palaeovalley-fill. The lateral and stratigraphic variability in fluvial-overbank architecture is interpreted as the interplay of several controls. Allogenic forcing factors include, tectonic subsidence that influences accommodation, sediment supply, and high frequency climate cycles associated with the flashy discharge regime and expressed in the mudrock colour changes and distribution of palaeosols. The depositional river style, variability in channel-belt stacking patterns and compensational stacking of some channel-belt/splay complexes is interpreted to be the result of autogenic channel avulsion, supported by an absence of significant erosion. The relative merits of basin-axial trunk river and distributive fluvial system (DFS) models are assessed from detailed architectural and stratigraphic outcrop studies.
348

Optimal "Belt-in-Seat" : A study to evaluate the optimal positioning of a Belt in a car's frontal seats

Bryggman, Elin January 2020 (has links)
The world is continuously moving, and so are the life on it. As our society is constantly evolving and the width of human needs are rising, do organization need to provide new solutions that can satisfy our needs. Consequently, every designer is going to meet new challenges whenever the situation calls for it. This is the situation that CEVT’s engineers have found themselves in and the reason as to why this engineering project has become relevant for their industrial development and innovation. The seatbelt designers at CEVT’s Restraints department have encountered a situation where it forces them to change their product as it can no longer be installed in the cars’ B-pillars. The company must investigate alternative positionings with regard to the car's new design criteria in order to recreate or improve the functionalities in both safety and comfort of their seatbelt system. My project objective is to investigate alternative positionings and components that are part of the classic three-point seatbelt system with an aim to ensure good user experience in the area of comfort. By the end of this thesis I ought to have answered the following Mission Statement: “Determine the most optimal positioning and components of the seatbelt system to reduce inertia for a fontal Belt-in-Seat, where the system’s performance should be comparable to the users’ experience from an installation of a seatbelt in a B-pillar.” To establish the best component combination out of the parts delivered from Autoliv AB and secure an optimal placement for the involved parts, have I followed the three-stage process described by IDEO (2015). The Inspiration phase has included a Literature study, benchmarking, analytical assessments of user needs as well as prepared and performed of a test on the seatbelt system. The Ideation phase was focusing on establishing a placement for the system's components through a brainstorming so that it could be mounted in a seat prototype prepared for the user experience tests performed. The last phase, Implementation, consisted of an analysis that was focusing on the feedback received from users of different anthropometry. But also concentrated on summarizing all data collected throughout the project to select the final concept for this assignment. / Världen och allt liv på jorden är i ständig rörelse. När samhället strävar efter utveckling uppkommer samtidigt nya behov hos människan och dess omgivning, vilket gör att olika organisationer och företag behöver leverera nya lösningar och designa artefakter för att tillfredsställa människans behov. Varje designer kommer att möta nya utmaningar när en situation tvingar dem att ändra sina produkter. Detta är en situation som CEVT:s bilbältesdesigners står inför och anledningen till att detta arbete blivit aktivt för företagets industriella utveckling inom innovation. Situationen som tvingar konstruktörerna att ändra bältessystemets design är att systemet inte längre kan monteras i passagerarbilens B-stolpar. Därför måste företaget undersöka alternativa positioneringar som överensstämmer med bilens designkriterier för att återskapa bältets funktionalitet som berör både säkerhet och komfort av deras bältessystem. Arbetets syfte är att undersöka alternativa positioneringar och de inkluderade komponenterna som utgör ett klassiskt tre-punkts bälte med målet att säkerställa en god användarupplevels inom området komfort. I slutet av projektet skall jag ha uppfyllt följande Mission Statement: “Bestäm den mest optimala positioneringen och komponenter av ett säkerhetsbältes system för att reducera krafterna från ett bältes-integrerat framsäte, en ’Belt-in-Seat’, där systemets prestandard skall vara jämförbart med användarens upplevelse av en installation av bältet i bilens B-stolpe.”   Jag har följt IDEOs (2015) tre-stegs process för att säkerställa den bästa kombinationen av komponenter som har tillhandahållits av Autoliv AB samt fastställa en optimal placering av varje komponent i systemet. Inspirationsfasen har inkluderat en litteraturstudie, benchmarking, analytiska bedömningar av användarens behov samt förberett och genomfört ett test på bältesystemets prestandard. Ideationsfasen fokuserade på att etablera en placering för systemets komponenter genom en brainstorming så att dessa kunde monteras i en sätesprototyp som förberetts inför testerna för att evaluera användarens komfortupplevelse. Den sista fasen, Implementation, bestod av en analys som fokuserade på feedbacken från testpersonerna som erhöll olika antropometri. Fasen kretsade kring att sammanfatta all data som samlats in genom hela projektet för att välja det slutliga konceptet för uppgiften.
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Kinas nya sidenväg : En teorikonsumerande fallstudie utifrån realism och liberalism / China's New Silk Road : A Theory Consuming Case Study From a Realistic And Liberal Perspective

Turesson, Christina January 2020 (has links)
This essay consists of a case study which examines China’s Belt and Road Initiative from two theoretical perspectives: realism and liberalism. The essay aims to enhance the comprehension of the Belt and Road Initiative by providing a realistic as well as a liberal interpretation of the project, and then comparing them to point out similarities and differences between these views. The essay concludes that the theoretical perspectives here work complementary rather than contradictory, and that what is hard to explain with one theory, often can be explained by the other. A liberal perspective sees more opportunities with the project, whereas a realistic one sees more risks but also necessities. The important aspects of the project from a liberal perspective concludes to be increased trade, international cooperation and interdependence, which are considered as risks from a realistic perspective. The main advantage is to increase power and security and legitimize the rule of the Chinese communist party, realistically speaking. Realism and liberalism interpret the goal with the project differently as well. Whereas realism sees BRI as a bold foreign policy project which aims to help China gain power to become a superpower and defeat poverty in China, liberalism view BRI as a foreign policy infrastructure project, built on trade, international cooperation and linking the world together.
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Konformní pás a cesta: měnící se postoje Ruska k čínské přítomnosti ve Střední Asii / Bandwagoning with the Belt and Road: Russia's changing attitude towards the Chinese presence in Central Asia post-Crimea

Bill, Simon January 2019 (has links)
BILL, Simon. Bandwagoning with the Belt and Road: Russia's changing attitude towards the Chinese presence in Central Asia post-Crimea. Praha, 2019. 78 pages. Master's thesis (Mgr.). Charles University, Faculty of Social Sciences, Institute of International Studies. Department of Russian and East European Studies. Supervisor Prof. Jan Šír, Ph.D. Abstract Since the fall of the Soviet Union, Russia has considered the Central Asian states to be a part of its exclusive sphere of influence. In recent years, however, China has also increased its presence in the region, investing heavily in the energy and transportation sectors. This is exemplified by its Belt and Road Initiative (BRI), specifically its Silk Road Economic Belt (SREB) component, which was launched in September 2013. As China increased its presence in the region, and Russia launched its own initiative, the Eurasian Economic Union (EaEU), the two powers seemed to be on a collision course. However, relations between the two never deteriorated as predicted. Instead, the opposite has happened. In 2015, Russia found itself internationally isolated due to its controversial actions in Ukraine and embraced China's initiative. This dissertation will seek to explain Russia's increasingly accommodating attitude towards China's growing investment and influence...

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