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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.
61

Staged Evolution

Borowiec, Gabriela Anna 19 May 2022 (has links)
Architecture has the power to reveal the complexities of man in nature through the degree of control in the process of form making. This process offers the opportunity to create different physical and psychological experiences dependent on its articulation. This is a study that explores the introduction of chance into the making process. Through a series of model studies, I explored how basic platonic solids, more specifically cube define spatial boundaries and how asymmetrical space could challenge its regularity and symmetry. Through chemical reactions randomized organic cavities were achieved that exposed contrast between regular exterior form and irregular interior form. This visual accent is embedded in irregular forms and is unrepeatable. The act of making exposes the intricate patterns created that replicate nature and the manifestation of material decay. With this in mind, as part of my thesis, I would like to apply the above discoveries into an observation tower. The orthogonal prisms, once deconstructed, draw attention to newly generated cavities and decay, revealing different conditions throughout from where visitors can enjoy views of Mallacoota's landscape. / Master of Architecture / Nature offers diverse design elements that architects can tap into to enhance human habitation. Building materials play a vital role in shaping visual and structural design in the built environment. Through the act of making, the process revealed the question of aesthetics in architecture through intricate forms and how architectural principles of spatial qualities interplay in creating inhabitable environments. As a part of the climate change investigation, I explored different production methodologies for visualizing the climatic crisis. This research investigates the nature of irregularity resulting from the subtraction of a platonic form. The deterioration process questions whether existing climatic changes are caused by nature or result from man-made actions. Intricate openings captured within defined geometrical boundaries trace the absence of the dissolved material, revealing that components introduced and their chemical reactions can build forms for people to inhabit. By leveraging the site and model studies, the proposed program addresses the local context, climate predictions, and scale and explores architecture performance in varying global warming conditions in the form of the observation tower.
62

Developing the Campus as a Learning Resource for Student Engagement on Low Carbon Futures

Hopkinson, Peter G. January 2011 (has links)
No
63

Ecosystem-based adaptation – In Theory and Practice : A case study of projects supported by the International Climate Initiative

Mellmann, Niels January 2015 (has links)
Ecosystem-based adaptation as a concept of adapting to the adverse effects of climate change has become a popular approach that enjoys a good reputation. However, the evidence base for it is rather thin. This thesis sets out to explore the challenges and limitations linked to projects that engage in the concept, in order to estimate the potential threat that may lie in the ignorance of them. Timescales of projects related to the concept shall be the second major focus of this thesis as it has not been sufficiently examined yet by the literature. Empirical material has been gathered and analyzed in the form of interviews with people who have been and are currently working in projects related to ecosystem-based adaptation. The results allow recommendations for the implementation of future projects, as lessons learned were identified.
64

Transportation Infrastructure and Heat Vulnerability

January 2016 (has links)
abstract: In the American Southwest, an area which already experiences a significant number of cooling degree days, anthropogenic climate change is expected to result in higher average temperatures and the increasing frequency, duration, and severity of heat waves. Climatological forecasts predict heat waves will increase by 150-840% in Los Angeles County, California and 340-1800% in Maricopa County, Arizona. Heat exposure is known to increase both morbidity and mortality and rising temperatures represent a threat to public health. As a result there has been a significant amount of research into understanding existing socio-economic vulnerabilities to extreme heat which has identified population subgroups at greater risk of adverse health outcomes. Additionally, research has shown that man-made infrastructure can mitigate or exacerbate these health risks. However, while recent socio-economic heat vulnerability research has developed geospatially explicit results, research which links it directly with infrastructure characteristics is limited. Understanding how socio-economic vulnerabilities interact with infrastructure systems is a critical component to developing climate adaptation policies and programs which efficiently and effectively mitigate health risks associated with rising temperatures. The availability of cooled space, whether public or private, has been shown to greatly reduce health risks associated with extreme heat. However, a lack of fine-scale knowledge of which households have access to this infrastructure results in an incomplete understanding of the health risks associated with heat. This knowledge gap could result in the misallocation of resources intended to mitigate negative health impacts associated with heat exposure. Additionally, when discussing accessibility to public cooled space there are underlying questions of mobility and mode choice. In addition to captive riders, a growing emphasis on walking, biking and public transit will likely expose additional choice riders to extreme temperatures and compound existing vulnerabilities to heat. / Dissertation/Thesis / Doctoral Dissertation Civil Engineering 2016
65

Greenland Ice Sheet Changes in Rates of Surface Elevation Change between 1978 and 2015

Candela, Salvatore G. 29 July 2019 (has links)
No description available.
66

Ocean Acidification on the California Coast| Responses of Marine Bryozoa to a High CO2 Future

Swezey, Daniel Sergio 23 March 2016 (has links)
<p> As a result of human activities, the level of CO<sub>2</sub> in the Earth&rsquo;s atmosphere has increased by nearly 40% since the industrial revolution. The rate of green house gas emission is accelerating, with current trends exceeding those predicted by &ldquo;worst case&rdquo; global climate change scenarios. The chemistry of the ocean is fundamentally changing as a result of increasing atmospheric CO<sub>2</sub>, which dissolves in seawater, making it more acidic, a process referred to as ocean acidification (OA). A rapidly expanding body of science is now being generated to understand the impact of this global environmental change. To date, most studies evaluating OA effects have centered on simplified laboratory analyses that expose single populations to short-term treatments in order to quantify responses of individuals. These designs offer a limited assessment of the degree to which phenotypic plasticity and local adaptation might influence the response of populations to OA. </p><p> To address these questions, I carried out studies on members of Phylum Bryozoa, a species-rich clade of calcified colonial marine invertebrates distributed throughout the global ocean. Bryozoans were selected as a model system for this work because the clade exhibits a broad array of growth and calcification strategies, and because of the relative paucity of data regarding their expected response to future acidification. In addition, bryozoans can be subdivided into genetically identical replicate clones, which can then be assigned to separate treatments, allowing variation across treatments to be uniquely partitioned into the variance components of statistical models. In order to culture bryozoans for comparative experiments, I designed and constructed a new flow-through OA system at the Bodega Marine Laboratory, capable of finely manipulating both the temperature and carbonate chemistry of seawater, allowing for controlled laboratory experiments of long duration. </p><p> In Chapter 1, I performed a comparative 9-month laboratory experiment examining the effects of ocean acidification on the native Californian bryozoan <i> Celleporella cornuta. C. cornuta</i> was sampled from two regions of coastline that experience different oceanographic conditions associated with variation in the intensity of coastal upwelling. Under different CO<sub>2 </sub> treatments, the biology of this bryozoan was observed to be remarkably plastic. Colonies raised under high CO<sub>2</sub> grew more quickly, invested less in reproduction, and produced skeletons that were lighter compared to genetically identical clones raised under current atmospheric values. Bryozoans held in high CO<sub>2</sub> conditions reduced their investment in skeletal carbonate, changed the Mg/Ca ratio of skeletal walls and increased the expression of organic coverings that may serve a protective function. Differences between populations in growth, reproductive investment, and the frequency of organic covering production were consistent with adaptive responses to persistent variation in local oceanographic conditions. </p><p> In Chapter 2, I tested whether skeletal mineralogy can vary plastically in some invertebrates using the cosmopolitan bryozoan <i>Membranipora tuberculata</i> as a model. In a 6-month laboratory experiment, I cultured genetic clones of <i>M. tuberculata</i> under a factorial design with varying food availability, temperature, and dissolved CO<sub>2</sub> concentrations. Elevated food availability increased growth in colonies while cold temperatures and high CO<sub>2</sub> induced degeneration of colony zooids. However, colonies were able to maintain equivalent growth efficiencies under cold, high CO<sub>2</sub> conditions, suggesting a compensatory tradeoff whereby colonies increase the degeneration of older zooids under adverse conditions, redirecting this energy to the maintenance of growth. Elevated food and cold temperatures also decreased Mg concentrations in skeletal material, and this skeletal material dissolved less readily under high CO<sub>2</sub> conditions. This suggests that these factors interact synergistically to affect dissolution potential in this and other species. </p><p> Finally, in Chapter 3, I explore stable isotope values for &delta;<sup> 18</sup>O and &delta;<sup>13</sup>C in the calcium carbonate structures of the bryozoan <i>Membranipora tuberculata</i>. I tested whether this species accurately records both temperature and pH variability during periods of coastal upwelling by analyzing &delta;<sup>18</sup>O and &delta;<sup> 13</sup>C in colonies grown in the field and in controlled laboratory cultures. Field-grown colonies were out planted next to a Durafet<sup>&reg;</sup> pH sensor, which provided a high-resolution record of the temperature and pH conditions these colonies experienced. &delta;<sup>13</sup>C was found to negatively co-vary with pH in both laboratory and field growth, and calculated field temperatures derived from laboratory &delta;<sup>18</sup>O temperature calibrations aligned with the records from the pH sensor. &delta;<sup>18 </sup>O<sub>c</sub> values were more depleted under low pH in laboratory trials, which stands in contrast to patterns observed in other taxa. This may indicate that <i>Membranipora</i> utilizes bicarbonate ion (HCO<sub> 3</sub><sup>-</sup>) in its calcification pathway, and could help explain why many bryozoan species appear to exhibit enhanced growth under high CO<sub> 2</sub> conditions. (Abstract shortened by ProQuest.)</p>
67

The biogeography and conservation of tidal marsh bird communities across a changing landscape

Correll, Maureen D. 20 April 2016 (has links)
<p> Given the current mass extinction crisis and continued fragmentation of resources worldwide, the outlook is dire for global biodiversity. Rising global temperature, sea levels, and storm frequency all create environmental conditions that can drive change in species abundance and distribution across a landscape. Those species reliant upon a single type of habitat and resource for survival, termed "specialists", are particularly vulnerable to change due to their inability to utilize a variety of resources well. As a result, specialism is now considered one of the dominant factors determining extinction of species. In this dissertation I explore the effects of disturbance on habitat specialist birds in tidal marshes of the northeastern United States. This ecosystem is important due to the significant ecosystem services it provides to humans, and supports several specialist species including the saltmarsh sparrow (<i>Ammodramus caudacutus</i>). I examine this specialist bird community across scales of space, time, and ecological organization to A) evaluate the impacts of disturbance on tidal marsh communities and B) provide findings and management recommendations for long-term maintenance and conservation of coastal marsh ecosystems, specifically as they pertain to salt-marsh specialist birds. In Chapter 1 I introduce my study system and give background for the current conservation status of tidal marsh birds. In Chapter 2 I generate population trends in the five species particularly specialized to tidal marsh using a database of historical records, and explore potential drivers for population change through local and regional habitat disturbance. In Chapter 3 I expand upon patterns in Chapter 2 ad quantify life history strategy in marsh birds across a gradient of habitat specialization to explore how this metric explains species persistence in tidal marshes. In Chapter 4 I test several theoretical hypotheses from disturbance ecology empirically using traditional and novel community metrics. Finally, in Chapter 5 I respond to research needs identified in Chapter 4 to develop a method for quantification of high-marsh habitat using remote sensing methods. I hope the findings presented here contribute towards understanding of the mechanisms driving biodiversity patterns on our planet and help inform conservation priorities within the changing tidal marsh landscapes.</p>
68

Weather Disasters and the Law: Examining the Need for Change in Canada

Joseph, Matthew 18 September 2014 (has links)
Canada is one of the wealthiest and most technologically advanced countries in the world. Yet, it fails to maintain an effective and comprehensive system for responding to weather-related hazards. The adverse socio-economic impacts of extreme weather are sufficiently serious to make climate change a threat to humanity. Weather events have lingering effects on peoples’ financial stability, particularly in low-income households. The goal of this thesis is to illuminate the nature of the legal, economic and social challenges posed by extreme weather. Thus, I present a comprehensive study of the Canadian institutional responses to these disasters. / Graduate
69

Satellite radar altimetry of sea ice

Laxon, Seymour William Clarke January 1989 (has links)
The thesis concerns the analysis and interpretation of data from satellite borne radar altimeters over ice covered ocean surfaces. The applications of radar altimetry are described in detail and consider monitoring global climate change, the role that sea ice plays in the climate system, operational applications and the extension of high precision surface elevation measurements into areas of sea ice. The general nature of sea ice cover is discussed and a list of requirements for sea ice monitoring is provided and the capability of different satellite sensors to satisfy needs is examined. The operation of satellite borne altimeter over non-ocean surfaces is discussed in detail. Theories of radar backscatter over sea ice are described and are used to predict the radar altimeter response to different types of sea ice cover. Methods employed for analysis of altimeter data over sea ice are also described. Data from the Seasat altimeter is examined on a regional and global scale and compared with sea ice climatology. Data from the Geosat altimeter is compared with co-incident imagery from the Advanced Very High Resolution Radiometer and also from airborne Synthetic Aperture Radar. Correlations are observed between the altimeter data and imagery for the ice edge position, zones within the ice cover, new ice and leads, vast floes and the fast ice boundary. An analysis of data collected by the Geosat altimeter over a period of more than two years is used to derive seasonal and inter-annual variations in the total Antarctic sea ice extent. In addition the retrieval of high accuracy elevation measurements over sea ice areas is carried out. These data are used to produce improved maps of sea surface topography over icecovered ocean and provide evidence of the ability of the altimeter to determine sea ice freeboard directly. In addition the changing freeboard of two giant Antarctic tabular icebergs, as measured by the Geosat altimeter, is presented. As a summary the achievements are reviewed and suggestions are made towards directions for further work on present data sets and for future data from the ERS-1 satellite.
70

Plant physiological and growth responses to elevated concentrations of atmospheric CO←2

McKee, Ian Fraser January 1992 (has links)
No description available.

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