This study identifies and critically assesses the social and physical consequences of, and possible responses to, sea-level rise and loss of land in the area that is now covered by the southern North Sea and English Channel/La Manche during the Mesolithic period. It suggests that Mesolithic studies still, despite debate on the matter, frame hunter fisher gatherers in economic terms. In this way, nature is seen as a separate entity to culture, the changing environment, therefore, becomes an external force against which people struggle. However, as an alternative, this thesis advocates an understanding of Mesolithic hunter fisher gatherers as an integral part of their changing world, suggesting that they would have had a fundamental awareness of these changes through a sensorial engagement, and acted accordingly. That said, it also suggests that, while not all people living in the area were equally affected by sea-level rise, the associated loss of land could have profoundly impacted people’s sense of place and being. It also highlights that, although sea-level rise and climate change occurred globally and on a millennial-scale, it unfolded and was experienced at a local and generational level. It therefore makes a case that to understand the human experience of early Holocene sea-level rise, it must be studied at the local-scale. This provides us with a better understanding of the effects of sea-level rise – a sense of the experience of it, rather than simply recording it as an abstract concept. Further, the local scale can identify problems that are not necessarily obvious from the larger scale. In this way, this thesis captures some of the nuances of environmental change that are frequently missing from the archaeological literature, and highlights the intense relationship between humans and their environment, providing a fresh approach to Mesolithic environment relations and a richer and more complex story of the effects of early Holocene sea-level rise.

The development and production of Canadian offshore petroleum deposits raises three key sets of issues of interest to economists. First are questions relating to the impact of royalties and taxes on producer decisions, and hence on the level and efficiency of resource taxation. Other issues concern the impacts on the overall economy during both the construction and production phases. A third set of issues relates to the distribution of powers and resource revenues between federal and provincial governments, including the links between provincial resource revenues and equalization payments. This thesis develops a numerically tractable economic model designed to examine these issues. At the model's core is a one-to-one relationship between development plans and production profiles. This property is exploited in simulating the behaviour of a price-taking, net-present-value-maximizing producer under conditions of certainty. The model is linked with a macroeconometric model of the Canadian economy to study the potential consequences of Hibernia, a petroleum deposit located in the Eastern Canadian offshore region. This deposit was chosen for analysis because its size, location and low costs (relative to current world oil prices) combine to raise all of the issues listed above. In most cases studied, producer responses to government policies result in the dissipation of less than five percent of the deposit's net present value to society. Although cases are identified where these responses have more serious consequences, the resulting dissipation of potential net benefits never exceeds 15 percent. The extension of specific forms of royalty and tax relief to the producer generally reduces the distortionary effects of government policies. The simulated exploitation of Hibernia induces small but sympathetic changes in most macroeconomic variables. The net crowding-out effects on other industries are shown to be relatively small, and to be more prevalent during the construction period. The results suggest that the larger share of the net benefits accruing to governments flows to the provincial treasury under three of the revenue-sharing systems modelled. However, Newfoundland and Labrador would lose a substantial portion of its Hibernia revenues under all of the equalization systems modelled. / Arts, Faculty of / Vancouver School of Economics / Graduate

Irgarol 1051 is a common antifoulant toxic to certain marine organisms. Submerged aquatic vegetation (SAV) are exposed to this herbicide when it leaches into the marine environment from painted structures, making SAVs ideal candidates to function as sentinel indicator of contamination. In the initial stage of this study, Coconut Grove and Key Largo Harbor were assessed for environmental exposure to Irgarol. Water, sediment and SAVs were collected, the latter two subject to automated solid phase extraction, and all samples analyzed by GC/MS-SIM for Irgarol and its metabolite, M1. Of the vegetation analyzed, Halodule and Syringodium had the highest capacity to bioaccumulate Irgarol and M1. The root system and leaf contributed negligibly and significantly, respectively, to Irgarol uptake. In the final stage, a transplant between Coconut Grove and Chicken Key showed that the biota Thalassia and Halodule were able to uptake and depurate Irgarol, respectively, over a period of 30 days.

O objetivo deste trabalho foi estudar as propriedades mecânicas do metal como soldado usando fluxo ativado na condição como recebido. Foram utilizadas cinco chapas base, sendo quatro delas de aço do tipo alta resistência e baixa liga (ABRL) e uma de aço carbono comum SAE 1020, que foram soldadas usando um único passe. O eletrodo utilizado foi o arame EM 12K , diâmetro de 4 mm e pó de ferro 400. As condições de soldagem utilizada foram: tensão de 34V, corrente de 660A, velocidade de soldagem de 30 cm/mim por minuto e uma adição de pó metálico de 373 g/m. Estas condições produzem um aporte de calor de 4,5 kJ/mm e uma diluição da chapa base em torno de 43%. Os ensaios mecânicos realizados forma de dureza, de tração e de impacto. A natureza das inclusões não metálicas foi investigada por microscopia eletrônica de varredura e análise por Energy Dispersive X RAY (EDS). Os resultados mostraram que as condições do fluxo e a diluição da chapa base alteraram a química nos metais como soldados, principalmente o oxigênio, isto permitiu mudanças significativas na temperabilidade. Como resultado as percentagens das microestruturas foram bastante alteradas principalmente na ferrita acicular, ocasionando mudanças nas propriedades mecânicas de dureza, tração e impacto. / The objective of this work was to study the properties of the metal as welded using activated flux in the condition as received. Five base plates, four of which were HSLA steel and one SAE 1020, that were welded using a single pass. EM 12K electrode and 400 metallic powder were used. The conditions for welding were: voltage 34V, current 660A, welding speed 30 cm/min and addition of metallic powder 373 Kg/M. These conditions produced a heat input of 4,5 kJ/mm and dilution in the base plate around 43%. Mechanical tests of hardness, impact resistance and tensile strength were carried out. The nature of non-metallic inclusions was investigated by scanning electron microscopy and analysis by Energy Dispersive X-Ray (EDS). The results showed that the conditions of the flux and the dilution of the base plate changed the chemical compositions in the metal as welded, mainly oxygen, which altered significantly the hardenability. As a result, the percentage of the microstructures changed, specially for acicular ferrite, allowing for changes in mechanical properties of hardness, impact resistance and tensile strength.

Gravity-driven membrane (GDM) filtration is one of the promising membrane bioreactor (MBR) technologies. It operates at a low pressure by gravity, requiring a minimal energy. Thus, it exhibits a great potential for a decentralized system, conducting household in developing and transition countries. Biofouling is a universal problem in almost all membrane filtration applications, leading to the decrease in flux or the increase in transmembrane pressure depending on different operation mode. Air scoring or regular membrane cleaning has been utilized for fouling mitigation, which requires increased energy consumption as well as complicated operations. Besides, repeating cleaning will trigger the deterioration of membranes and shorten their lifetime, elevating cost expenditures accordingly. In this way, GDM filtration stands out from conventional MBR technologies in a long-term operation with relative stable flux, which has been observed in many studies. The objective of this study was to monitor the biofilm development on a flat sheet membrane submerged in a GDM reactor with constant gravitational pressure. Morphology of biofilm layer in a fixed position was acquired by an in-situ and on-line OCT (optical coherence tomography) scanning at regular intervals for both visual investigation and structure analysis. The calculated thickness and roughness were compared to the variation of flux, fouling resistance and permeate quality, showing expected consistency. At the end of experiment, the morphology of entire membrane surface was scanned and recorded by OCT. Membrane autopsy was carried out for biofilm composition analysis by total organic carbon (TOC) and liquid chromatography with organic carbon detection (LC-OCD). In addition, biomass concentration was obtained by flow cytometer and adenosine tri-phosphate (ATP) method. The data of biofilm components indicated a homogeneous biofilm structure formed after a long-term running of the GDM system, based on the morphology observation by OCT images. The superiority of GDM in both flux maintaining and long-term operation with production of high quality effluent was demonstrated, as well as the suitability of OCT for biofouling monitoring was emphasized.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / This paper, evaluates a proposal for an external bend fluvial erosion control, using submerged vanes as velocity and shear stress control, verifying its effectiveness by modeling in Iber to calculate the scour produced by discharges with different return periods. The results indicate that the velocity, shear stress and scour decrease along the curve, due to submerged vanes.

The main diet of herbivorous waterfowl, such as swans, coots, and ducks, consists of submerged macrophytes. The grazing by waterfowl below the surface may affect the biomass and species composition of the submerged plants. The vegetations is, however, also affected by e.g. water turbidity, periphyton growing on the plants and water temperature. This literature study aimed to assess the impact of waterfowl on the biomass and production of submerged vegetation in shallow, eutrophic lakes and how this may vary with the season. The review showed that the density of submerged vegetation biomass varies during the seasons but tends to be highest in the summer. Waterfowl density is usually highest during autumn migration. According to experimental field studies in which waterfowl were excluded from protected areas, showed that protected plants had longer shoots and fewer stumps and, in several studies, also higher biomass, than in areas where waterfowl resided free. Although several studies have shown that waterfowl affect the biomass of macrophytes in different ways, is still uncertain to what degree and whether this has a negative or positive impact on the species composition of vegetation in a longer time perspective. However, alternative state shifts in shallow eutrophic lakes from a clear to a turbid water state have not been shown to be caused by waterfowl. With climate change, the time and place of waterfowl migration and wintering will most probably change. This could lead to altered pressure and seasonality of the grazing by waterfowl on submerged vegetation. / Växtätande sjöfåglars diet består huvudsakligen av undervattensvegetation. Fåglarna betar av växterna oftast under ytan, men undervattensvegetationens biomassa och artsammasättning påverkas inte bara av sjöfåglar, utan också av en rad andra faktorer, till exempel vattnets grumlighet, påväxtalger och vattentemperatur. Syftet med denna litteraturstudie var att undersöka under vilka förutsättningar betning från sjöfåglar har betydelse för undervattensvegetation. Växternas biomassa har visats minska i samband med sjöfåglars födointag, om den huvudsakligen består av vattenväxlighet. Vegetationens täthet varierar under året men uppnår störst täthet under sommaren. Sjöfåglar har visats vara i störst täthet under höstmånaderna, i samband med flyttning. Experimentella studier har genomförts genom att jämföra skyddade områden där sjöfåglar utestängts med öppna områden där sjöfåglar kunnat beta. I de skyddade områdena var växterna generellt längre och hade flera skott. Där fanns också färre stubbar än i de öppna områdena. Flera studier har visat att sjöfåglarna påverkar vegetationens biomassa på olika sätt men det är fortfarande osäkert i vilken grad och om detta över längre tid har en negativ eller positiv påverkan på vegetationens artsammansättning. I och med nutida klimatförändringar kan sjöfåglars tidpunkt och plats för migration och övervintring att förändras. Detta kan leda till att sjöfåglarna inte emigrerar från sjöar och kommer därav med största sannolikhet påverka undervattensvegetationen.

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While side-scan sonar has become a valuable geophysical tool for forensic water searches, controlled research is paramount to determine the best practices for searches in aquatic environments as it provides a structured environment in which to investigate variables that influence the effectiveness of the technology and provides valuable experience for sonar operators. The purpose of this research is to conduct controlled research in order to evaluate the applicability of side-scan sonar to searches involving submerged firearms and proxy cadavers. In addition, the best practices for employing this technology in forensic searches in freshwater ponds and lakes in a humid, subtropical environment in Central Florida would be developed. Five street-level firearms were submerged in a pond, and two sets of three pig carcasses (Sus scrofa), utilized as proxies for human bodies, were staked to the bottom of a pond for this research. Transects were conducted over the firearms and the pig carcasses utilizing side-scan sonar. The first set of pig carcasses represented a child size (30-32 kg) and the second set a small adult size (51-54 kg). Results show that firearms were not detected due to the terrain and small size. However, this technology successfully located small to medium-sized proxy carcasses on a flat, sandy lake bottom when experienced operators were conducting the search. Conversely, vegetation obscured submerged bodies. While the smaller carcasses were difficult to detect throughout the data collection, medium-sized carcasses were easily discerned. Moreover, the medium-sized carcasses decomposed at the same rate as previous studies and were visible throughout each stage of decomposition. Finally, employing a 900 kHz frequency with a 20 m swath-width provided the best search parameters. Therefore, in the appropriate conditions, iv side-scan sonar is an effective tool for locating submerged bodies in freshwater lakes and ponds in a humid, subtropical environment.

Human occupation of the New England region of North America during the early Holocene has long been established archaeologically. However, the data exists almost solely from terrestrial sites. Vast portions of aerial land once available to early occupants of the area for resource procurement and living surfaces are now submerged. Underwater pre-Contact resources embedded in these submerged landforms will undeniably contribute to a holistic understanding of New England's cultural history. Examination of current archaeological procedures reveal that the archaeological standards, practices, and theories commonly employed in terrestrial archaeology are largely not being extended past the coastline into the underwater environment. This is due, in part, to the past history of professional skepticism regarding the preservation and accessibility of terrestrial archaeological deposits post-Holocene sea level rise. A report of global, submerged, terrestrial archaeology projects that show submerged, intact resources challenge this skepticism. A detailed review of an underwater survey in Boston Harbor, designed to predict, locate, and investigate submerged pre-Contact sites, is used as a case study to argue that these resources deserve the same rigorous study as terrestrial archaeological resources. Post-glacial deposition may act as an agent of preservation in New England waters, and past concerns of transgressive erosion are discussed in light of current geophysical research. Recommendations of how and why submerged pre-Contact archaeological resources should become commonplace within archaeological inquiry are supported by advances in technology, increased geophysical survey of the marine environment and knowledge of the prevailing laws governing archaeological resources underwater.