Nature, Material, Home: Exploring the Human-Nature Connection through Handmade Building Materials

This thesis challenges the distance humans have put between themselves and nature through an exploration in biogenic building materials and a degrowth approach to dwelling construction. The research conducted identifies the core causes of the historically constructed divide between society and nature and recommends changes to degrow it. A series of experiments conducted at multiple scales informed the feasibility of the real-world applications of the thesis. The exploration of biogenic construction materials brings the theory of degrowth forward using a hands-on approach. The thesis proposes an architecture that presents an alternative approach to material production and building construction to create a dwelling that positions construction and human habitation within nature

Intra-tidal variation of stratification in a semi-arid estuary under the impact of flow regulation

The Jaguaribe River is the largest semi-arid Brazilian river and represents an important water source for the state of Ceará. The Castanhão Weir, built to regulate the flow of the Jaguaribe, began operating successfully in the 1990s. As a result, the hydrodynamic regime of the estuary has undergone alteration and is no longer subject to the former annual climatological variability of the dry and rainy seasons. This paper introduces an assessment of the changes in the hydrological conditions resulting from the construction of the weir and investigates the structure of the density stratification in the estuary. A field experiment was conducted at the end of the dry season in November 2009, during which salinity and temperature were monitored at different levels for three tidal cycles. The temporal variations in salinity and temperature during the tidal cycles were 16 psu and 1.5°C, respectively. The salinity exhibited a vertical variation of four units, while the temperature variation was much lower. Several stratification indicators were calculated from the observed density: the stratification coefficient, the Brunt-Väisälä frequency and the potential energy anomaly. The results showed that the parameters behave similarly, differences being observed only in their relative magnitudes. The vertical structure of the estuary exhibited marked stratification during the ebb tide but vertical homogeneity during both flood and high tide. With the regularized flow existing under present conditions, the estuary exhibits hyposaline and a partially mixed structure for the period studied, despite the typical expectation of a hypersaline and well-mixed vertical structure.O rio Jaguaribe é o maior rio do semi-árido brasileiro, constituindo uma importante fonte de água para o estado do Ceará. Na década de 1990 entrou em operação o Açude do Castanhão com o objetivo de regularizar a vazão do rio Jaguaribe, o qual obteve grande sucesso. Como consequência foi alterado o regime hidrodinâmico do estuário, o qual atualmente não está mais sujeito a variabilidade climatológica anual de estações seca e chuvosa. O presente trabalho apresenta uma avaliação da mudança do regime hidrológico antes e após a construção do açude, e investiga a estrutura de estratificação da densidade nos estuários. Foi realizado um experimento de campo em novembro de 2009, no fim da estação seca, quando a salinidade e temperatura da água foram monitorados em diferentes níveis durante três ciclos de maré. A variação temporal da salinidade e temperatura durante os ciclos de maré foram de 16 psu e 1,5ºC, respectivamente. A salinidade chegou a apresentar variação vertical de 4 unidades, enquanto que a variação da temperatura foi bem inferior. Foram calculados parâmetros indicadores da estratificação a partir da densidade: coeficiente de estratificação; frequência de Brunt-Väisälä; e a anomalia da energia potencial. Os resultados mostraram que os parâmetros comportam-se da mesma maneira, apenas com diferença da magnitude relativa de seus valores. A estrutura vertical do estuário apresentou estratificação pronunciada durante a fase de vazante da maré, e verticalmente homogênea na fase de enchente da maré e durante a preamar. Dada as condições presentes, com vazão regularizada, o estuário apresenta padrão de estratificação parcialmente misturado e hiposalino, quando seria esperado uma condição bem misturada e hipersalina para o período estudado

Het ontwerpen en maken van een designtool voor sleephopperzuigers

Mechanical, Maritime and Materials EngineeringMarine and Transport TechnologyShip Design, Production and OperationOEMO 92/1

Sleephopperzuigers

Mechanical, Maritime and Materials EngineeringMarine and Transport TechnologyShip Design, Production and OperationOEMO 92/0

Lithostratigraphy of the Kirkwood Formation (Uitenhage Group), including the Bethelsdorp, Colchester and Swartkops Members, South Africa

Abstract The Jurassic – Cretaceous Kirkwood Formation forms part of the Uitenhage Group, the earliest deposits to fill Mesozoic rift basins that developed in what is now the southern Cape of South Africa during the breakup of Gondwana. The Kirkwood Formation is not only palaeontologically extremely important, having yielded diverse assemblages of vertebrate, invertebrate and plant fossil taxa, but also contains suitable source rocks for hydrocarbon systems offshore of the southern Cape of South Africa. The Kirkwood Formation comprises chronostratigraphic markers in the form of radiometrically dateable volcaniclastic deposits and age-diagnostic invertebrate fossils, which may provide robust dates for the depositional history of the Uitenhage Group. The Kirkwood, including the Bethelsdorp, Colchester and Swartkops Members, is 2210 m at its thickest and comprises sandstones and mudstones deposited in fluvial and lacustrine depositional settings from the Tithonian to Valanginian. These microfossil-based ages may only apply to the unit in its type area in the Algoa Basin and not to its lithostratigraphic correlatives in the other Mesozoic rift basins, which have highly variable ages ranging from Middle Jurassic to Early Cretaceous.</jats:p

Lithostratigraphy of the Enon Formation (Uitenhage Group), South Africa

Abstract The Uitenhage Group represents the earliest deposits that filled Mesozoic rift basins in the southern Cape of South Africa during the fragmentation of the supercontinent Gondwana. The sedimentology of the Enon Formation records the development of alluvial systems that drained the region since the onset of Gondwanan rifting, and therefore plays an important role in our understanding of early landscape evolution along the southern African continental margin. The mostly coarse conglomeratic unit was deposited continuously in actively subsiding, but separated, rift basins. As a result, the deposits are diachronous between basins and display highly varied thicknesses of up to well over 2000 m.</jats:p

Sea level variability in South African estuaries

Sea level variability in the coastal ocean affects water levels in adjacent estuaries over a wide range of periods and to varying distances landward. An assessment is given here of the responses of a number of South African estuaries, focusing on tidal and subtidal periods where the dominant effects are found and the necessary data are available. Shorter period inputs tend to be limited to mouth regions and require more detailed, higher frequency data. Subtidal fluctuations, in particular those caused by coastal trapped waves, play an important part in the dynamics of estuaries in the Western Cape and Eastern Cape. In many cases their influence dominates tidal oscillations farther upstream, and it is apparent that such fluctuations must be considered in any assessment of estuarine characteristics, and indeed their upstream extent. Nonetheless, it should be emphasised that each estuary has unique properties, and must be assessed individually. Sea level variability changes dramatically north of the Kei Estuary, and particularly off the coast of KwaZulu-Natal. Unfortunately, few measurements were available from these estuaries, but the mouth conditions of the estuaries and the build-up of river flow appear to be important factors in resulting estuary water levels. These results show that using only tidal variations in the sea can result in very misleading conclusions about concurrent water levels in estuaries