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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.
21

Cartografia morfológica de detalhe e intervenções antrópicas no Alto Jacareí: subsídios à avaliação da degradação ambiental do Sistema Cantareira / Morphological cartography of detail and interventions on the high Jacareí: contribution to assessment of environmental degradation of the Cantareira System

Soares, Fabiana Pegoraro 14 August 2008 (has links)
A presente pesquisa baseia-se na utilização da cartografia morfológica de detalhe para a identificação de mudanças ambientais de ciclo curto em áreas com intervenção antrópica e foi desenvolvida em uma sub-bacia hidrográfica pertencente ao Sistema Cantareira de abastecimento da Região Metropolitana de São Paulo, localizada próxima à divisa entre São Paulo e Minas Gerais, na borda da Serra da Mantiqueira, entre os municípios de Joanópolis (SP) e Extrema (MG). Com esse objetivo o estudo permitiu a identificação do nível de preservação do meio físico de um dos principais sistemas produtores de água para a Região Metropolitana de São Paulo e, eventualmente, o reconhecimento das conseqüências das intervenções antrópicas na área e o fornecimento de dados para gestão desses recursos hídricos. Para tanto foram elaborados e comparados mapas de uso da terra, morfológico, de declividade e de indicadores de degradação, obtidos através da fotointerpretação de imagens de 1962 e de 2003, na escala de 1:25.000, e em levantamento de campo, onde foram identificadas evidências morfológicas de degradação física (formas erosivas e tipos de erosão). Para relacionar a morfologia original, às intervenções antrópicas e às mudanças morfológicas ocorridas na área, optou-se por apoiar-se em estudos de Geomorfologia Antrópica e de cartografia geomorfológica de detalhe. Para esta última, utilizou-se da técnica de mapeamento morfológico proposta por Savigear (1965), adaptada à complexidade morfológica da área. A correlação entre os mapas morfológico, de declividade e do uso da terra, permitiu uma análise comparativa da área da sub-bacia hidrográfica e o apontamento de evidências de degradação ocorrida na área. Além disso, os mapas podem fornecer embasamento para posterior monitoramento geomorfológico dos processos e materiais interligados às formas mapeadas (originais ou antropogênicas). As mudanças ambientais, sobretudo as formas erosivas, foram notadas principalmente quando associadas às ações de desmatamento e pastagem, o que comprova a necessidade de um manejo adequado quanto ao uso da terra em áreas de mananciais. / The present research is based on detailed morphological mapping that had produced to identify short term environmental changes in man-made surfaces and drainage basin which belong to the most important System of water supply of Sao Paulo Metropolitan area. The study area is seated on Mantiqueira mountain range border, between the municipality of Joanopolis (SP) and Extrema (MG). With this aim, the study has allowed to discuss about the preservation level of physical systems as well the effects of human interventions in drainage basin and in their water supplies. For these, maps of land use, morphology, slope declivity and degradation indicators were produced and compared. They were obtained from interpretation of aerial photographs dated 1962 and 2003, in scale 1:25.000, and from field studies, where morphological evidence of physical degradation was identified mainly by rain erosion forms. One of the most important steps of this study was the correlation of original morphology with man-made or morphological changes. Studies about Anthropogenic Geomorphology and Geomorphological Detailed Mapping were decisive factors to support that correlation. The morphological mapping technique proposed by Savigear (1965) was used, and it was adapted to the morphological complexity of this area. The correlation between the produced maps has permitted to see the degradation evidences occurred in the areas. Besides this, the maps can provide data to later geomorphological watching of process and materials linked to the mapped forms (originals or anthropogenics). Environmental changes, especially erosive forms, were noted associated to deforestation and pasture mainly, proving that management of land use in headwater areas is needed.
22

Primary succession in man-made wetlands: biodiversity, structure and dynamics of macrofaunal assemblages

Ruhí i Vidal, Albert 20 January 2012 (has links)
Man-made wetlands are often created to compensate for the loss or degradation of natural wetlands, but little is known about the processes taking place in these artificial environments, especially at the community level. Throughout this thesis, we have assessed the phenomena of primary succession over different time (short-, mid- and long-term) and spatial scales (local, regional, interregional levels), applying different approaches (taxonomic and functional) and subject groups (invertebrates and amphibians). Our main findings regarding time scales show a 3-phase successional pattern in Mediterranean man-made wetlands’ communities, where at the short term (1 year) colonization processes dominate; at mid term perspectives (2 to 7 years) succession signs begin to be conspicuous, and later on (≥ 10 years) parameters such as species richness reach an asymptote. At that moment, some biological strategies dominate, and biodiversity surrogates indicate that communities are indistinct between man-made and natural wetlands. Regarding spatial effects, we corroborated that both local and regional factors affect the establishing communities. Particularly, the low hydrological stability of the Mediterranean region has enhanced biological traits favoring resilience and resistance to disturbances when comparing Mediterranean and cold temperate aquatic communities. Even within the Mediterranean region, low levels of hydrological stability have significant effects on the successional dynamics. In these cases, local communities are highly nested within regional natural ones, and so are not able to make net contributions to regional richness. We also showed the influence of the regional pool of recruiters over local communities, both in the case of invertebrates and amphibians. Especially for the latter group, man-made Mediterranean temporary ponds (MTPs) can play an important role in their conservation. / Les zones humides de nova creació són sovint concebudes per compensar la pèrdua i degradació de les naturals, però el coneixement dels processos que tenen lloc en aquests ambients artificials encara és superficial, especialment a nivell de comunitat. Al llarg d’aquesta tesi, hem analitzat el fenomen de la successió primària a diferents escales temporals (a curt, mitjà i llarg termini) i a diferents escales espacials (a nivell local, regional i interregional), mitjançant diverses aproximacions (taxonòmiques i funcionals) i subjectes (invertebrats i amfibis). Les nostres aportacions pel que fa a les escales temporals mostren un patró de successió basat en 3 fases, on a curt termini (1 any) dominen els processos de colonització; en perspectives de mitjà termini (2 a 7 anys) els signes de successió comencen a ser conspicus, i més tard (≥ 10 anys) paràmetres com la riquesa d’espècies arriben a una asímptota. En aquesta fase avançada, algunes estratègies biològiques dominen, i els índexs de biodiversitat indiquen que les comunitats poden ser indistintes entre les llacunes naturals i les de nova creació. Pel que fa als efectes espacials, hem corroborat que tant factors locals com regionals afecten les comunitats que s’hi estableixen. En particular, la baixa estabilitat hidrològica de la regió Mediterrània ha afavorit trets biològics que proveeixen resiliència i resistència enfront de pertorbacions, sobretot quan es comparen amb les comunitats pròpies del clima temperat fred. Fins i tot dins la mateixa regió Mediterrània, nivells baixos d’estabilitat hidrològica poden tenir efectes importants en la dinàmica de la successió. En aquests casos, les comunitats locals estan altament aniuades en les naturals a nivell regional, i per tant difícilment poden fer contribucions netes a la riquesa regional. També hem mostrat la influència del pool regional de colonitzadors sobre les comunitats locals, tant en el cas dels invertebrats com en el dels amfibis. Especialment per aquest darrer grup, les Basses Temporànies Mediterrànies (BTMs) de nova creació poden jugar un paper important per a la seva conservació.
23

Interdependent Response of Networked Systems to Natural Hazards and Intentional Disruptions

Duenas-Osorio, Leonardo Augusto 23 November 2005 (has links)
Critical infrastructure systems are essential for the continuous functionality of modern global societies. Some examples of these systems include electric energy, potable water, oil and gas, telecommunications, and the internet. Different topologies underline the structure of these networked systems. Each topology (i.e., physical layout) conditions the way in which networks transmit and distribute their flow. Also, their ability to absorb unforeseen natural or intentional disruptions depends on complex relations between network topology and optimal flow patterns. Most of the current research on large networks is focused on understanding their properties using statistical physics, or on developing advanced models to capture network dynamics. Despite these important research efforts, almost all studies concentrate on specific networks. This network-specific approach rules out a fundamental phenomenon that may jeopardize the performance predictions of current sophisticated models: network response is in general interdependent, and its performance is conditioned on the performance of additional interacting networks. Although there are recent conceptual advances in network interdependencies, current studies address the problem from a high-level point of view. For instance, they discuss the problem at the macro-level of interacting industries, or utilize economic input-output models to capture entire infrastructure interactions. This study approaches the problem of network interdependence from a more fundamental level. It focuses on network topology, flow patterns within the networks, and optimal interdependent system performance. This approach also allows for probabilistic response characterization of interdependent networked systems when subjected to disturbances of internal nature (e.g., aging, malfunctioning) or disruptions of external nature (e.g., coordinated attacks, seismic hazards). The methods proposed in this study can identify the role that each network element has in maintaining interdependent network connectivity and optimal flow. This information is used in the selection of effective pre-disaster mitigation and post-disaster recovery actions. Results of this research also provide guides for growth of interacting infrastructure networks and reveal new areas for research on interdependent dynamics. Finally, the algorithmic structure of the proposed methods suggests straightforward implementation of interdependent analysis in advanced computer software applications for multi-hazard loss estimation.
24

Cartografia morfológica de detalhe e intervenções antrópicas no Alto Jacareí: subsídios à avaliação da degradação ambiental do Sistema Cantareira / Morphological cartography of detail and interventions on the high Jacareí: contribution to assessment of environmental degradation of the Cantareira System

Fabiana Pegoraro Soares 14 August 2008 (has links)
A presente pesquisa baseia-se na utilização da cartografia morfológica de detalhe para a identificação de mudanças ambientais de ciclo curto em áreas com intervenção antrópica e foi desenvolvida em uma sub-bacia hidrográfica pertencente ao Sistema Cantareira de abastecimento da Região Metropolitana de São Paulo, localizada próxima à divisa entre São Paulo e Minas Gerais, na borda da Serra da Mantiqueira, entre os municípios de Joanópolis (SP) e Extrema (MG). Com esse objetivo o estudo permitiu a identificação do nível de preservação do meio físico de um dos principais sistemas produtores de água para a Região Metropolitana de São Paulo e, eventualmente, o reconhecimento das conseqüências das intervenções antrópicas na área e o fornecimento de dados para gestão desses recursos hídricos. Para tanto foram elaborados e comparados mapas de uso da terra, morfológico, de declividade e de indicadores de degradação, obtidos através da fotointerpretação de imagens de 1962 e de 2003, na escala de 1:25.000, e em levantamento de campo, onde foram identificadas evidências morfológicas de degradação física (formas erosivas e tipos de erosão). Para relacionar a morfologia original, às intervenções antrópicas e às mudanças morfológicas ocorridas na área, optou-se por apoiar-se em estudos de Geomorfologia Antrópica e de cartografia geomorfológica de detalhe. Para esta última, utilizou-se da técnica de mapeamento morfológico proposta por Savigear (1965), adaptada à complexidade morfológica da área. A correlação entre os mapas morfológico, de declividade e do uso da terra, permitiu uma análise comparativa da área da sub-bacia hidrográfica e o apontamento de evidências de degradação ocorrida na área. Além disso, os mapas podem fornecer embasamento para posterior monitoramento geomorfológico dos processos e materiais interligados às formas mapeadas (originais ou antropogênicas). As mudanças ambientais, sobretudo as formas erosivas, foram notadas principalmente quando associadas às ações de desmatamento e pastagem, o que comprova a necessidade de um manejo adequado quanto ao uso da terra em áreas de mananciais. / The present research is based on detailed morphological mapping that had produced to identify short term environmental changes in man-made surfaces and drainage basin which belong to the most important System of water supply of Sao Paulo Metropolitan area. The study area is seated on Mantiqueira mountain range border, between the municipality of Joanopolis (SP) and Extrema (MG). With this aim, the study has allowed to discuss about the preservation level of physical systems as well the effects of human interventions in drainage basin and in their water supplies. For these, maps of land use, morphology, slope declivity and degradation indicators were produced and compared. They were obtained from interpretation of aerial photographs dated 1962 and 2003, in scale 1:25.000, and from field studies, where morphological evidence of physical degradation was identified mainly by rain erosion forms. One of the most important steps of this study was the correlation of original morphology with man-made or morphological changes. Studies about Anthropogenic Geomorphology and Geomorphological Detailed Mapping were decisive factors to support that correlation. The morphological mapping technique proposed by Savigear (1965) was used, and it was adapted to the morphological complexity of this area. The correlation between the produced maps has permitted to see the degradation evidences occurred in the areas. Besides this, the maps can provide data to later geomorphological watching of process and materials linked to the mapped forms (originals or anthropogenics). Environmental changes, especially erosive forms, were noted associated to deforestation and pasture mainly, proving that management of land use in headwater areas is needed.
25

American Feminist Manifestos and the Rhetoric of Whiteness

Adams, Elliot C. 27 June 2006 (has links)
No description available.
26

Amphibian Use of Man-Made Pools Created by Military Activity on Kisatchie National Forest, Louisiana

Ecrement, Stephen M. 23 September 2014 (has links)
No description available.
27

Anticipating Urban Evacuations: A Planning Support System for Impact Reduction

Belhadj, Joshua S. 23 April 2008 (has links)
No description available.
28

Structural Composite Material with Novel Cellulose Fibre Reinforcement / Strukturellt sammansatt material med nyskapande förstärkning av cellulosafibrer

Murrone, Mauro Antonio January 2024 (has links)
In recent decades, the necessity to find a completely environmentally friendly substitute for synthetic fibres in composite applications has intensified, driven by the objective of reducing emissions in both the production and disposal of composite components. Natural fibres present a potential solution, yet they have some issues such as the inhomogeneous quality of their cross-section and mechanical properties, depending on different aspects, for example, growing conditions and the amount of intake water. Another potential solution is organic man-made fibres, such as fibre made from Cellulose NanoFibrils, which do not present the previously cited drawbacks.This thesis investigates and compares the potentials of organic fibres, either man-made or natural, in composite reinforcement applications. To accomplish this, organic fibres are integrated into composite plates using two distinct thermoset matrices, epoxy and vinyl ester, respectively via methods of hot pressing and vacuum infusion. Subsequently, the produced composite plates undergo tensile testing, with the results being compared with the theoretical values. Furthermore, microscopy is employed to examine the adhesion at the interface between reinforcement and matrix.The findings indicate that man-made fibres from Cellulose NanoFibrils bind more efficiently with thermoset matrices compared to flax fibres, making them more adept as reinforcement materials for thermoset composites. / Under de senaste decennierna har behovet av att hitta en helt miljövänlig ersättning för syntetiska fibrer i kompositapplikationer intensifierats, drivet av målet att minska utsläppen både vid produktion och avfallshantering av kompositkomponenter. Naturliga fibrer presenterar en potentiell lösning, men de har vissa problem som den ojämna kvaliteten på deras tvärsnitt och mekaniska egenskaper, beroende på olika aspekter, till exempel växtförhållanden och mängden intaget vatten. En annan potentiell lösning är organiska konstgjorda fibrer, som fibrer tillverkade av cellulosa nanofibriller, som inte har de tidigare nämnda nackdelarna.Denna avhandling undersöker och jämför potentialen hos organiska fibrer, antingen konstgjorda eller naturliga, i kompositförstärkningsapplikationer. För att uppnå detta integreras organiska fibrer i kompositplattor med hjälp av två olika termohärdande matriser, epoxi och vinyl-ester, via metoder för varmpressning och vakuuminfusion. Därefter genomgår de producerade kompositplattorna dragprovning, med resultaten jämförda med de teoretiska värdena. Dessutom används mikroskopi för att undersöka vidhäftningen vid gränssnittet mellan förstärkning och matris.Resultaten indikerar att konstgjorda fibrer från cellulosa nanofibriller binder effektivare med termohärdande matriser jämfört med linfibrer, vilket gör dem mer lämpliga som förstärkningsmaterial för termohärdande kompositer.
29

Metoder för att undersöka effekterna av naturvårdshänsynen i skogsbruket efter den nya skogsvårdslagen / Methods for studying effects of nature consideration in forest management after the new forestry act

Eneland, Anna January 2010 (has links)
<p>Detta arbete har undersökt skillnaderna mellan den nuvarande skogsvårdslagen och den föregående. Undersökningen har bestått av två delar, där ena delen är en litteraturstudie av lagarna och den andra är en fältstudie av metoder för att mäta naturhänsynsförändring. Som komplement till fältstudien har en litteraturstudie av undersökningsparametranas naturvårdsnytta. Litteraturstudien av lagarna gick till på följande sätt, inledningen av båda lagarna och hänsynsparagraferna har lästs och jämförts. Fältstudie har gjorts efter metoder som har arbetats fram och sedan testats i fält. De undersökningsområden som har testats är stående död ved med undergruppen konstgjorda högstubbar, grova träd, hänsynsytor, trädslagsfördelning och boträd. Testningen skedde i trakterna kring Orsa i Dalarnas län. Resultatet blev att hälften av undersökningsområdena skulle kunna användas i en större studie efter några modifikationer. Andra hälften av undersökningsområdena kan det inte på grund av att referensdata saknas. Lagstudien visade att den största skillnaden mellan de båda lagarna ligger i att i den nuvarande har man jämställt miljömålet med produktionsmålet. Det finns även en attitydförändring till en större öppenhet mot naturvård i den nya lagen.</p> / <p>This work has examined the difference between the new forestry actand the previous one. The research has been divided in two parts, one is a literature study of the law and the other is a field study of methods for measuring the change in consideration of nature. As compliment too the field study a literature study of the research parameters nature conservation benefits. The examine of the laws were done in this way, the introduction of the laws and the nature conservation paragraphs were read and compared. For the field study methods have been worked out and tested in the field. The research parameters that have been tested are standing dead wood with subgroup man made snags, thick trees, consideration of nature areas, distribution of tree species and nesting trees. The field testing were made in the neighboring forest of the city Orsa in the administrative province of Dalarna.The results of the field methods are that half of the methods have a possible use in a larger study with some modifications. The other half are missing references data to be useful.The biggest differences between the laws are that in new law the goals for production and environment care are equal. There is also an change in attitude towards greater consideration of nature.</p>
30

Metoder för att undersöka effekterna av naturvårdshänsynen i skogsbruket efter den nya skogsvårdslagen / Methods for studying effects of nature consideration in forest management after the new forestry act

Eneland, Anna January 2010 (has links)
Detta arbete har undersökt skillnaderna mellan den nuvarande skogsvårdslagen och den föregående. Undersökningen har bestått av två delar, där ena delen är en litteraturstudie av lagarna och den andra är en fältstudie av metoder för att mäta naturhänsynsförändring. Som komplement till fältstudien har en litteraturstudie av undersökningsparametranas naturvårdsnytta. Litteraturstudien av lagarna gick till på följande sätt, inledningen av båda lagarna och hänsynsparagraferna har lästs och jämförts. Fältstudie har gjorts efter metoder som har arbetats fram och sedan testats i fält. De undersökningsområden som har testats är stående död ved med undergruppen konstgjorda högstubbar, grova träd, hänsynsytor, trädslagsfördelning och boträd. Testningen skedde i trakterna kring Orsa i Dalarnas län. Resultatet blev att hälften av undersökningsområdena skulle kunna användas i en större studie efter några modifikationer. Andra hälften av undersökningsområdena kan det inte på grund av att referensdata saknas. Lagstudien visade att den största skillnaden mellan de båda lagarna ligger i att i den nuvarande har man jämställt miljömålet med produktionsmålet. Det finns även en attitydförändring till en större öppenhet mot naturvård i den nya lagen. / This work has examined the difference between the new forestry actand the previous one. The research has been divided in two parts, one is a literature study of the law and the other is a field study of methods for measuring the change in consideration of nature. As compliment too the field study a literature study of the research parameters nature conservation benefits. The examine of the laws were done in this way, the introduction of the laws and the nature conservation paragraphs were read and compared. For the field study methods have been worked out and tested in the field. The research parameters that have been tested are standing dead wood with subgroup man made snags, thick trees, consideration of nature areas, distribution of tree species and nesting trees. The field testing were made in the neighboring forest of the city Orsa in the administrative province of Dalarna.The results of the field methods are that half of the methods have a possible use in a larger study with some modifications. The other half are missing references data to be useful.The biggest differences between the laws are that in new law the goals for production and environment care are equal. There is also an change in attitude towards greater consideration of nature.

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