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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.
161

Remembering Change: An Architectural Response to Rising Sea Levels

Stevens, Martha Joyce 27 July 2023 (has links)
A rising sea level threatens historic buildings and towns that tie together the collective identity of a community, but because the disaster is often prolonged and the loss occurs all around us, the current model for memorials will not accommodate the grief the future holds. Memorials are meant to aid in remembering and often point to a specific event or place where a historic event happened. If the loss is ongoing and happening everywhere, the memorial will need to adapt and address more universal concepts to be inclusive. A memorial can no longer simply point to a moment in the past. They must help educate about important issues and experiences that impact daily life. Future memorials need to address diverse narratives and complex histories to remain relevant when cultural values shift. There is an architectural opportunity to reflect on more universal experiences that are on-going and affect everyone, but these memorials need to operate at a local level to make big issues, like climate change, more digestible. By focusing on one symptom, like sea level rise, and using a specific instance of loss as the backdrop, visitors can experience the profound impact of climate change firsthand. The Historic Point Lookout Lighthouse will become the site for a new theoretical tidal park and climate change memorial. It will memorialize what has been lost to rising sea levels and heighten visitors' awareness of their own relationships to water. The design will present the dynamics of water in the short term, mid term, and long term to make the subtle changes of rising sea levels evident. The site will transform over the course of the day with tidal action, over the years with material weathering, and over the decades with sea level rise. Locals will have a place to return to as the surrounding area is swallowed by the bay and they are forced to relocate. The building itself will act as a metaphorical anchor and storytelling device, marking the place that experienced a historical and cultural erasure because of rising sea levels. As the building changes and transforms with the landscape, it will become embedded in the collective identity of the Bay and the memories of its visitors. / Master of Architecture / A rising sea level threatens historic buildings and towns that tie together the collective identity of a community, but because the disaster is often prolonged and the loss occurs all around us, the current model for memorials will not accommodate the grief the future holds. Memorials are meant to aid in remembering and often point to a specific event or place where a historic event happened. If the loss is ongoing and happening everywhere, the memorial will need to adapt and address more universal concepts to be inclusive. A memorial can no longer simply point to a moment in the past. They must help educate about important issues and experiences that impact daily life. Future memorials need to address diverse narratives and complex histories to remain relevant when cultural values shift. There is an architectural opportunity to reflect on more universal experiences that are on-going and affect everyone, but these memorials need to operate at a local level to make big issues, like climate change, more digestible. By focusing on one symptom, like sea level rise, and using a specific instance of loss as the backdrop, visitors can experience the profound impact of climate change firsthand. The Historic Point Lookout Lighthouse will become the site for a new theoretical tidal park and climate change memorial. It will memorialize what has been lost to rising sea levels and heighten visitors' awareness of their own relationships to water. The design will present the dynamics of water in the short term, mid term, and long term to make the subtle changes of rising sea levels evident. The site will transform over the course of the day with tidal action, over the years with material weathering, and over the decades with sea level rise. Locals will have a place to return to as the surrounding area is swallowed by the bay and they are forced to relocate. The building itself will act as a metaphorical anchor and storytelling device, marking the place that experienced a historical and cultural erasure because of rising sea levels. As the building changes and transforms with the landscape, it will become embedded in the collective identity of the Bay and the memories of its visitors.
162

Assessment of Biogeochemical Maturation of Overburden Disturbed by Surface Mining

Poncelet, Dominique M. 15 August 2011 (has links)
No description available.
163

The Surface Chemistry and Geochemistry of Feldspar Weathering

Houston, William Norman 09 1900 (has links)
<p> In this study the experiments were designed to measure the geochemical and surface charge (zeta potential) changes with time for two crushed samples of feldspar (Na-fs and K-fs) over the pH range of most natural waters (5 to 9). These experiments show: </p> <p> (a) the importance of adsorption/desorption phenomena in both short-term and long-term feldspar dissolution, and probably for chemical weathering in general; </p> <p> (b) that the generalized curve which characterizes the geochemical data (an initial rapid rise to a peak followed by a decrease to a lower, either constant or later increasing value) is consistent with a consideration of the adsorption/desorption process (i.e., the formation of the double layer) taking place at the feldspar surface and with the simple dissolution of the mineral; </p> <p> (c) that the cation-silica ratios (Na₂O/SiO₂, K₂O/SiO₂, CaO/SiO₂) of the solution compared to those in the original feldspar indicate an initially incongruent dissolution which tends towards congruency during the latter part of the experiments. </p> <p> From information in the Iiterature and the results of these experiments. it may be concluded that: </p> <p> (a) the most important or master variables in chemical weathering are abrasion, minerologic or crystallographic factors such as twinning, exsolution regions, impurities, fractures and grain size, and solution composition and concentration. pH does not appear to be a master variable in most natural waters, especially for long-term weathering, and the chemical composition of the mineral phase is also not a good criterion for predicting weathering behaviour; and </p> <p> (b) the most extreme chemical weathering should occur in a high energy environment, either for physical reasons (i.e., high abrasion due to extreme relief) or for chemical reasons (i.e., high rainfall). </p> / Thesis / Master of Science (MSc)
164

WEATHERING: THE EVER-CHANGING FINISH

HEABERLIN, CLIFF 01 July 2004 (has links)
No description available.
165

CHEMICAL WEATHERING AND ORGANIC CARBON TRANSPORT IN AN ACTIVE MOUNTAIN BELT: SIERRA DE LAS MINAS, GUATEMALA

McAdams, Brandon Collins 20 December 2012 (has links)
No description available.
166

How much does fungi contribute to weathering? : A Literature Review

Bejtoft, Emil January 2024 (has links)
Ectomycorrhizal fungi contribute to weathering and may be used as an alternative to fertilizers. Their usefulness is dependent on how much they can contribute to the weathering that takes place in the same area. This review discusses the current literature on how much ectomycorrhizal fungi contribute to the total chemical weathering rate. There are few studies that document said contribution, with most geomycological weathering studies only reporting weathering numbers for the fungi. The weathering contribution towards apatite and olivine appears to be higher (at 28% and 16% respectively) than the 0.2% and 0.5% attributed to feldspar and 2% attributed to biotite. More research is needed to understand how much fungi can contribute to weathering. It would be preferable to study multiple species of both minerals and fungi at once in the same drainage area.
167

Long-term performance of water repellants on rendered autoclaved aerated concrete

Kus, Hülya January 2002 (has links)
Many failures of external walls made of porous buildingmaterials are caused by excessive moisture content,particularly after driving rain and under long duration ofmoist conditions. Lack of sufficient protection againstexposure conditions is one of the reasons for external wallsprematurely demonstrating failures, i.e. properties andperformance above/below critical levels. Silicon-based waterrepellants are increasingly used in order to improve theperformance of both old and new buildings. Water repellants areexpected to prolong the service life and improve the durabilityof wall components by preventing or minimising water ingressinto the structure and thus delaying the deteriorating effectsof the atmosphere. To date, various kinds of water repellantshave been developed. However, only limited research has beencarried out, particularly on the long-term field exposuretesting. Existing research is mainly focused on the performanceof surface treatments of concrete structures and the protectionof historical buildings built of stone, brick and wood, and isprimarily based on short-term laboratory testing. The aim ofthis research work is to study the long-term performance,degradation processes and ageing characteristics of renderedautoclaved aerated concrete (AAC) with and without waterrepellants. Investigations are carried out by physical andchemical analysis of fresh samples, samples naturally weatheredby long-term field exposure and samples artificially aged byshort-term accelerated laboratory tests. Two differentapplication of water repellants are employed: impregnation ofrendering surface with an aqueous product and as additive inpowder form mixed into the fresh rendering mortar. Continuousmoisture and temperature monitoring of naturally exposed testsamples are also included in the study. Wetcorr sensors andresistance-type nail electrodes are used to measure the surfacemoisture and the moisture content in the material,respectively. This thesis describes the experimental set-upand presents the results from site monitoring and laboratorytests of unexposed, naturally and artificially exposed samples(freeze-thaw and UV+water). The results from the continuousmoisture measurements are compared with the results obtainedfrom the full-scale test cabin built within the EUREKA-projectE 2116 DurAAC. The test cabin has the same basic measurementinstruments for continuous monitoring of moisture andtemperature. An attempt has been made to develop methods forlong-term performance assessment of water repellants to be usedin service life prediction. The combination of data obtainedfrom the field measurements with data obtained from thelaboratory tests and analysis may also meet practical needs ofthe end-users.
168

Long-term performance of water repellants on rendered autoclaved aerated concrete

Kus, Hülya January 2002 (has links)
<p>Many failures of external walls made of porous buildingmaterials are caused by excessive moisture content,particularly after driving rain and under long duration ofmoist conditions. Lack of sufficient protection againstexposure conditions is one of the reasons for external wallsprematurely demonstrating failures, i.e. properties andperformance above/below critical levels. Silicon-based waterrepellants are increasingly used in order to improve theperformance of both old and new buildings. Water repellants areexpected to prolong the service life and improve the durabilityof wall components by preventing or minimising water ingressinto the structure and thus delaying the deteriorating effectsof the atmosphere. To date, various kinds of water repellantshave been developed. However, only limited research has beencarried out, particularly on the long-term field exposuretesting. Existing research is mainly focused on the performanceof surface treatments of concrete structures and the protectionof historical buildings built of stone, brick and wood, and isprimarily based on short-term laboratory testing. The aim ofthis research work is to study the long-term performance,degradation processes and ageing characteristics of renderedautoclaved aerated concrete (AAC) with and without waterrepellants. Investigations are carried out by physical andchemical analysis of fresh samples, samples naturally weatheredby long-term field exposure and samples artificially aged byshort-term accelerated laboratory tests. Two differentapplication of water repellants are employed: impregnation ofrendering surface with an aqueous product and as additive inpowder form mixed into the fresh rendering mortar. Continuousmoisture and temperature monitoring of naturally exposed testsamples are also included in the study. Wetcorr sensors andresistance-type nail electrodes are used to measure the surfacemoisture and the moisture content in the material,respectively. This thesis describes the experimental set-upand presents the results from site monitoring and laboratorytests of unexposed, naturally and artificially exposed samples(freeze-thaw and UV+water). The results from the continuousmoisture measurements are compared with the results obtainedfrom the full-scale test cabin built within the EUREKA-projectE 2116 DurAAC. The test cabin has the same basic measurementinstruments for continuous monitoring of moisture andtemperature. An attempt has been made to develop methods forlong-term performance assessment of water repellants to be usedin service life prediction. The combination of data obtainedfrom the field measurements with data obtained from thelaboratory tests and analysis may also meet practical needs ofthe end-users.</p>
169

Weathering and conservation of monuments constructed from tuff and sandstone in different environmental conditions / Case Studies from Mexico, Germany, Jordan and Cambodia

Wedekind, Wanja 18 July 2016 (has links)
No description available.
170

Weathering study of the gneissic rock mass from the Monte Seco tunnel region, southeastern Brazil. / Estudo do intemperismo de um maciço rochoso gnáissico da região do túnel Monte Seco, sudeste do Brasil.

Monticelli, João Paulo 15 May 2019 (has links)
This study refers to a qualitative and quantitative weathering characterization of a gneiss rock mass (weathering profile, intact rock and discontinuity) in a tropical region. The rock mass was excavated for a construction of an unlined railway tunnel, which during its useful life began to present block instability problems linked to the weathering and the time of exposure of the rock. The weathering of the rock mass and its weathering grades are approached in the geological and geotechnical points of view, covering bibliographical review on the subject, field inspection, direct and indirect investigations, and laboratory tests: petrographic analysis, X-ray diffraction, physical properties and durability index, sclerometry, ultrasonic test, uniaxial and diametral compression. / Este estudo se refere à caracterização qualitativa e quantitativa do intemperismo de um maciço rochoso gnáissico (perfil de intemperismo, rocha intacta e descontinuidades) em uma região tropical. O maciço foi escavado para a construção de um túnel ferroviário não revestido, que ao longo da vida útil começou a apresentar problemas de instabilidade de blocos vinculados ao intemperismo e ao tempo de exposição da rocha. O intemperismo do maciço rochoso e os seus graus de alteração foram abordados do ponto de vista geológico e geotécnico, levando-se em consideração uma ampla revisão bibliográfica sobre o tema, inspeção de campo, investigações diretas e indiretas, e os seguintes ensaios laboratoriais: análise petrográfica, difratometria de raios X, índices físicos e de durabilidade, esclerometria, ultrassom, compressão uniaxial e diametral.

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