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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.
71

Disturbance, recovery and resilience in tropical forests : a focus on the coastal peat swamp forests of Malaysian Borneo

Cole, Lydia Eve Spencer January 2013 (has links)
Tropical forests have existed for up to one hundred million years, and today provide many ecosystem services vital for human well-being. They also harbour great biodiversity, which, in addition to its intrinsic value, plays a key role in the functioning of these ecosystems. Despite their local to global significance, there are still many knowledge gaps concerning the dynamic processes that govern the functioning of tropical forests. Rapid rates of deforestation and landscape conversion, predominantly for logging and industrial agriculture, are limiting the time and opportunity available to collect the information needed to fill these gaps. This research aims to shed light on the long-term ecological functioning of tropical forests, specifically investigating the history of disturbance in these ecosystems and the response of forest vegetation to past perturbations. The carbon-rich tropical peat swamp forests found along the coast of Sarawak, Malaysian Borneo, are a central focus of this study. For these forests in particular, a large deficit of knowledge surrounding their history and unique ecological functioning is coupled with some of the highest conversion rates of all tropical forest ecosystems across the world. In this thesis, palaeoecological data has been used to reconstruct temporal variability in forest vegetation coincident with external perturbations in order to identify changes in the resilience of these ecosystems through time, via indicators such as slowing rates of recovery and reduced regeneration of forest vegetation. Results suggest that tropical forest ecosystems have, for the most part, shown resilience to natural disturbances in the past, ranging from instantaneous localised tree-fall to longer-term regional climatic change; but that recent anthropogenic disturbances, of novel forms and greater intensities, are jeopardizing the potential for forest recovery and thus compromising ecosystem resilience. These findings enhance our understanding of the ecology of tropical peat swamp forests, and tropical forests more broadly. They also provide a context for contemporary tropical forest management, allowing for predictions on future responses to disturbance and enabling more ecologically sustainable landscape planning.
72

Trembling Earth

Chan, Amy Beth 01 January 2008 (has links)
This thesis details the literary and visual influences in my work, the definition of American Gothic, and its connection it to my work. Literary sources such as Edgar Allan Poe and Fanny Kemble help spark a vision of the landscape. Visual influences include Japanese woodblock prints, scenic wallpapers, vintage postcards and Victorian mourning pictures. My regional explorations span the James River, Tidewater swamps and architecture within the city of Richmond.My work depicts local history and ecology inspired by Richmond and the surrounding region. Subtle Gothic elements add anxiety to the otherwise pastoral scenes. Gothic foreboding in the work questions our ecological future and the permanence of our human presence in the landscape.
73

Narrative Processes in Urban Planning: A Case Study of Swamp Gravy in Colquitt, Georgia

Pate, Ronald David 01 January 2012 (has links)
In 1990 many in Colquitt, Georgia considered themselves to be a dying town due to the loss of jobs and outmigration that occurred when labor intensive farming transitioned to the machine. In response citizens brought in a theater director from Chicago who helped them launch a performance series of inclusive stories that were acted by local volunteers. The resulting series called Swamp Gravy has run from 1992 to present (2012), and has led to purported claims of community revitalization. The purpose of this study was to discover what this ongoing narrative community engagement meant to the people of Colquitt in regards to: community experiences that produced new relationships (including those between Blacks and Whites); personal empowerment; the coproduction of an emerging and diverse community identity; and institutional and economic development. Methods for this case study included narrative interviews of participants, attendees and local citizens, as well as observation of the town and the performances, and document analysis. Many participant volunteers and attendees became Swamp Gravy enthusiasts, and describe their experiences as coming out into a meaningful experience of community, which included forming relationships with diverse others (including those of a different race). The enthusiasts speak of growing into larger community responsibilities with others for the common good, and feel that ongoing and inclusive storytelling is very important to coproducing a diverse heritage that informs the future of their city. Other attendees (predominantly the business community) describe the benefits of Swamp Gravy as instrumental to having given the town recognition (identity) as an entertaining tourist attraction that exposed individual talent, boosted individual confidence, and enhanced social connectivity. Others in Colquitt were indifferent or resistive to the coming out that the performances invite. Most everyone recognizes that Swamp Gravy has attracted outside tourists which has boosted economic development, occasioned the renovation of downtown Colquitt square and the formation of institutions to continue to attract and accommodate visitors from afar. This case is theorized in terms of the emerging communicative turn in planning that juxtaposes the planner as mediator or facilitator, and stakeholders as co-producers. The findings in this case study support that the Swamp Gravy form of narrative process has some potential for guiding stakeholders to a just diversity in cities, neighborhoods and towns, and as such should be studied further. Urban planning in situations of urban renewal may be one place where utilizing this form of meaningful engagement could lead to discovery of new identities, which may both inform and motivate a just plan to be coproduced.
74

Habitat and Seasonal Distribution of the North American River Otter (Lontra canadensis) and Vertebrate Species Assemblages in Two Protected Areas of the Florida Everglades

Hamilton, Catherine Faye 01 November 2014 (has links)
The Florida Everglades ecosystem is threatened by human development, increased pollution, freshwater scarcity, and invasive species; factors that have negatively impacted the Everglades and native species health and populations. Man-made canals and levies have redirected the natural flow of fresh water from Lake Okeechobee into the Florida Everglades, starving central and south Florida ecosystems of necessary fresh water and nutrients. Through the efforts of the Comprehensive Everglades Restoration Project (CERP), freshwater is being redirected back into central and south Florida, returning the sheet flow of water back into the Everglades. Monitoring species abundance in the Everglades is a beneficial conservational tool for assessing restoration efforts from CERP. As a semi-aquatic apex predator, river otters (Lontra canadensis) are a useful health bio-indicator for the Florida Everglades. In order to conduct future population studies of river otters in the Florida Everglades, it must first be ascertained where they can be found and what time of year they are most likely to be sighted. For this study, Moultrie infrared game cameras were used to photograph the presence or absence of river otters within the five main habitats in the Everglades; the pinelands, hardwood hammock, cypress swamp, marsh prairie, and mangrove estuary at two protected areas in the Florida Everglades (Big Cypress National Preserve and Fakahatchee Strand State Park). River otters were most frequently sighted in the hardwood hammock habitat, but were also found in the cypress swamp. The large majority of river otter sightings occurred during dry season, which is thought to be a function of restricted water availability and aquatic mobility. Future population studies of river otters would be most productive in the hardwood hammock and cypress swamp habitats during dry season. Game camera images along with field opportunistic sightings, resulted in a variety of species documented. This provided valuable information of species richness and distribution within and amongst the habitats. The hardwood hammock was found to be the most species rich habitat, having over half the species observed in the study in this habitat. The Aves class was the most abundantly observed in the Everglades, and was most frequently sighted during the dry season. As a refuge for migratory birds, the Everglades house the majority of bird species during the winter months, which occur during dry season. The Aves class was most frequently sighted in the pinelands habitat during dry season. This habitat, being the highest in elevation and therefore the driest, shows a stronger resemblance to most northern bird habitats then does the water-saturated wetlands found throughout the Everglades. The mangrove estuary was the most commonly occurring outlier, having the least species overlap when compared to the other habitats. All other habitats in the Everglades are freshwater wetlands, while the mangrove estuary is a brackish environment, which limits the species that are unable to tolerate saline conditions. Further studies of species abundance throughout the Everglades will aid in monitoring CERP restoration efforts over time.
75

Detection of Zoonotic Bacteria and Paragonimus kellicotti in Red Swamp Crayfish and The Assessment of Traditional Crayfish Preparation

Palillo, Jack A. January 2021 (has links)
No description available.
76

Разработка принципов построения малогабаритного снегоболотохода с дистанционным управлением : магистерская диссертация / Development of design principles for small-size remotely controlled snow-and-swamp mobiles

Шонохова, Н. А., Shonokhova, N. A. January 2018 (has links)
Выпускная квалификационная работы выполнена на тему «Разработка принципов построения малогабаритного снегоболотохода с дистанционным управлением». Расчетно-пояснительная записка содержит 198 листов, 90 рисунков, 16 таблиц, 11 источников, 42 приложения. Объектом разработки является малогабаритный снегоболотоход с дистанционным управлением, предназначенный для инженерно-изыскательских работ. Цель работы – разработка принципов построения малогабаритного снегоболотохода с дистанционным управлением, в том числе разработка новых узлов, выбор из ранее представленных, модернизация и реконструкция элементов, разработанных для других машин. В результате проведенной работы спроектированы 3 шнековых движителя, 4 подвески, 2 системы управления, также рассмотрены блоки задания скорости, кольцевые распределители импульсов и преобразователи «Код-напряжение». В проекте также рассмотрены вопросы безопасности труда, радиационная безопасность и природопользование и охрана окружающей среды. В разделе технико-экономических показателей приведены единовременные, текущие и приведенные затраты. / The goal of the research was to justify the selection of various structural elements and control systems on the basis of both design parameters and the analysis of assigned tasks. Thus, a number of existing designs of machines, propellers and suspensions were considered in the course of the study, all of which could be used for different purposes: for example, it is more rational to utilize motor-in-wheel propellers to glide over the water, since those are most lightweight and waterproof of all, and to choose a spring suspension – since it contains the minimal number of elements which could fail in the water medium. As to the systems of control, the selection of their control blocks is made on the criteria of reliability, since it is necessary to ensure no-failure operation of the system as a whole. As a result of the work, 3 screw propellers, 4 suspensions, 2 control systems were designed, and a few speed assignment blocks, circular distributors of impulses and number-to-voltage converters were considered. The project also analyses the problems of work safety, radiation safety, conservation and environment control. The section on project feasibility cites nonrecurring, current and reduced costs.
77

Historical changes in the geomorphology of the Ottawa River (NW Ohio, U.S.A.) due to urbanization and land clearance

Webb, Laura D. 04 August 2010 (has links)
No description available.
78

Etudes écologique, floristique, phytosociologique et ethnobotanique de la forêt marécageuse de Lokoli, Zogbodomey - Bénin / Ecological, floristic, phytosociological and ethnobotanical studies of the swamp forest of Lokoli, Zogbodomey - Benin

Dan, Céline 29 June 2009 (has links)
Etudes écologique, floristique, phytosociologique et ethnobotanique de la forêt marécageuse de Lokoli (Zogbodomey – Bénin)<p><p>La forêt marécageuse de Lokoli, située dans le sud du Bénin est une formation non protégée, bien qu’elle soit la seule forêt marécageuse avec un cours d’eau permanent connue en Afrique de l’Ouest. Pour envisager une prise de décision de conservation et de protection de cet écosystème forestier, il est important de disposer d’une meilleure connaissance de sa flore, de sa végétation et de son fonctionnement. C’est dans ce cadre que la présente étude a été envisagée. Les données collectées concernent le milieu naturel, la structure de la forêt, la régénération naturelle des espèces et les usages faits des Produits Forestiers Non Ligneux (PFNL).<p>Le milieu naturel se compose d’un substratum acide (pH variant de 3,5 à 5,5) et argilo-sableux. Le cortège floristique de cette forêt est composé de 241 espèces réparties en 185 genres et 70 familles dont des espèces endémiques (Uapaca paludosa) ou en danger (Hallea ledermannii), Nauclea xanthoxylon, etc. <p>Sept groupements végétaux ont été identifiés (forêt primaire inondée à Alstonia congensis et Xylopia rubescens, forêt secondaire inondée à Ficus trichopoda et Spondianthus preussii et raphiale à Raphia hookeri et Anthocleista vogelii en forêt ;forêt ripicole à Alchornea cordifolia et Mitragyna inermis, savane marécageuse à Ficus asperifolia et Paullinia pinnata ;prairie marécageuse à Cyclosorus gongylodes et Polygonum pulchrum et enfin prairie marécageuse à Rhynchospora corymbosa et Ludwigia abyssinica en lisière) avec des précisions sur leurs caractéristiques floristiques, biologiques, phytogéographiques et écosociologiques. Les mésophanérophytes sont abondants en forêt alors qu’en lisière, ce sont les microphanérophytes qui sont les plus nombreux. Ces groupements constituent un refuge pour de nombreuses espèces animales dont Barboides britzi, poisson déterminé pour la première fois en 2006. D’après cette étude, on note une bonne régénération des espèces forestières malgré une recrudescence des trouées liées à l’installation de champs de Colocasia esculenta. <p>Parmi les 75 espèces, source de PFNL recensées, les produits et sous-produits issus de Raphia hookeri sont les plus exploités car ils constituent pour les populations riveraines d’importantes sources de revenus. Ces PFNL sont exploités à Lokoli pour plusieurs usages à savoir l’alimentation, l’emballage, boisson alcoolisée, recettes médicinales, construction, etc. Le nombre de pieds de Raphia hookeri saignés par an est de 15.452 par 320 exploitants dont 148 cueilleurs, 81 transformateurs et 91 commerçants ;ce qui fournit aux exploitants des revenus de l’ordre de 28.000 à 159.000 FCFA (42,7 à 242,4 euros) par mois et par exploitant, sans oublier les autres activités menées par les riverains dans cet écosystème. On note une forte pression anthropique sur cette formation qu’il est donc urgent de protéger. <p>En effet, elle dispose d’importants atouts qui militent en faveur de sa conservation. Elle abrite des espèces végétales et animales rares, endémiques, vulnérables et en danger (inscrites sur la liste rouge de l’UICN), telles que :Hallea ledermannii, Uapaca paludosa, Nauclea xanthoxylon, Cercopithecus erythrogaster erythrogaster, Cercopithecus mona, Colobus vellerosus, Ceriagrion citrinum Campion, Barboides britzi, etc. La forêt marécageuse de Lokoli joue un rôle de refuge pour toutes ces espèces qui y trouvent leur niche écologique. Sur le plan socio-économique, la FML fournit aux populations riveraines des revenus pour leur subsistance. Toutes ces potentialités font d’elle une Forêt à Haute Valeur pour la Conservation (FHVC) et elle pourrait constituer une véritable réserve de biosphère dans le Sud-Bénin.<p> <p>Ecological, floristic, phytosociological and ethnobotanical studies of the swamp forest of Lokoli (Zogbodomey - Benin)<p><p>The swamp forest of Lokoli, located in the south of Benin, is a non-protected area, although it is the only swamp forest in West Africa accompanied by a river which always contains water. To be able to make decisions concerning the conservation and protection of this forest ecosystem, it is important to have a better knowledge of its flora, its vegetation and its ecology and dynamics. It is within this framework that the present study was considered. The data that were collected relate to the natural environment, the structure of the forest, the natural regeneration of the species and the uses of the Non Timber Forest Products (NTFP).<p>The natural environment is composed of a substratum which is acid (pH varying from 3.5 to 5.5) and loamy-sandy. The floristic composition of this forest is composed of 241 plant species from 185 genera and 70 families.<p>Seven vegetation types were identified: 1. Inundated primary forest with Alstonia congensis and Xylopia rubescens; 2. Inundated secondary forest with Ficus trichopoda and Spondianthus preussii; 3. Raphia forest with Raphia hookeri and Anthocleista vogelii; 4. Riparian forest with Alchornea cordifolia and Mitragyna inermis; 5. Marshy savanna with Ficus asperifolia and Paullinia pinnata; 6. Marshy savanna with Cyclosorus gongylodes and Polygonum pulchrum; and 7. Marshy savanna with Rhynchospora corymbosa and Ludwigia abyssinica. Precise details are given on their floristic, biological, phytogeographical and phytosociological characteristics. The mesophanerophytes are abundant in forest whereas at forest edges the microphanerophytes are most numerous. These vegetation types constitute a refuge for many animal species, for example Barboides britzi, a species of fish first identified in 2006. This study noted a good regeneration of forest species, in spite of disturbance related to the installation of fields of Colocasia esculenta.<p>About 75 investigated NTFP are exploited in Lokoli for many purposes, among which food, packaging, alcoholic drinks, medicines, construction, etc. Among the listed NTFP, the products and by-products made from Raphia hookeri are the most important because they are important sources of revenue for the inhabitants of the area. The number of stems of Raphia used per year for palm wine production is 15.452 by the 320 inhabitants, including 148 gatherers, 81 transformers and 91 tradesmen. This provides to the inhabitants an income of about 28,000 to 159,000 FCFA per month and per inhabitant, without forgetting the other activities undertaken by these inhabitants. This results in a strong human pressure on the vegetation of the area which is therefore in urgent need of protection.<p>The vegetation of the Lokoli forest has important values which indicate its conservation concern. It shelters plant and animal species that are endemic and/or endangered or vulnerable according to the red list of the IUCN, such as: Hallea ledermannii, Uapaca paludosa, Nauclea xanthoxylon, Cercopithecus erythrogaster erythrogaster, Cercopithecus mona, Colobus vellerosus, Ceriagrion citrinum Campion, Barboides britzi, etc. The swamp forest of Lokoli is a refuge for all these species who find here their ecological niche. On the socio-economic level, the Lokoli forest provides to the inhabitants an income for their subsistence. The Lokoli forest in southern Benin is a forest with a high conservation value and it has the potential to become a “biosphere reserve”.\ / Doctorat en Sciences / info:eu-repo/semantics/nonPublished
79

Технология производства кузова вездехода, предназначенного для эксплуатации в условиях Крайнего Севера : магистерская диссертация / The technology of production of the body of an all-terrain vehicle designed for operation in the Far North

Ворухайлов, И. С., Vorukhailov, I. S. January 2018 (has links)
В данной магистерской диссертации произведен обзор и анализ наземных транспортных средств, в частности колесных вездеходов на шинах сверхнизкого давления, получивших наиболее широкое распространение на территориях Крайнего Севера. Выявлены характерные особенности и условия эксплуатации автомобильного транспорта в арктической части РФ. На основании полученной информации разработана концепция вездехода на шинах сверхнизкого давления, наиболее адаптированного для использования в северных широтах. Исходя из предложенной конструкции, составлен технологический процесс изготовления и последующей сборки кузова данной колесной машины. Определены необходимые конструкционные материалы, используемые при производстве кузова вездехода. / In this master's dissertation, a survey and analysis of land vehicles, in particular wheeled all-terrain vehicles on ultra-low pressure tires, which have been most widely used in the Far North. The characteristic features and conditions of operation of motor transport in the Arctic part of the Russian Federation are revealed. Based on the information received, was developed the concept of an all-terrain vehicle on ultra-low pressure tires, most adapted for use in the northern latitudes. Proceeding from the proposed design, was compiled the technological process of manufacturing and subsequent assembly of the body of this wheeled vehicle. The necessary structural materials used in the manufacture of the body of an all-terrain vehicle are determined.
80

Carbon Dynamics of Subtropical Wetland Communities in South Florida

Villa Betancur, Jorge Andres 06 June 2014 (has links)
No description available.

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