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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.
181

Externe Vorspannung / External Prestressing

Borer, Erich Karl 27 May 2010 (has links) (PDF)
Mit der vorliegenden Arbeit soll ein Beitrag geleistet werden, die lokalen Tragmechanismen eines Brückenhohlkastens im Bereich der Feldumlenkstellen (Feldlisenen) zu untersuchen und zu optimieren. Beim Entwurf einer Brücke gewinnt die Frage der Dauerhaftigkeit u.a. in Deutschland und der Schweiz eine immer zentralere und grössere Bedeutung. Dadurch können die laufenden Kosten reduziert werden, während ausserhalb dieser beiden Länder im Allgemeinen mehr Gewicht auf die rationelle Fertigung und die Kostenersparnis in der Bauphase gelegt werden. Die Dauerhaftigkeit von extern vorgespannten Brücken mit ihren relativ geringen Wartungs- und Unterhalts- bzw. Instandstellungskosten sind das Hauptargument für diese Bauweise. Bei Vorspannung ohne Verbund sind für externe Spannglieder grössere Verankerungskonstruktionen erforderlich. Dies, weil die Spannglieder nicht im Steg selbst, sondern mit einem Mindestabstand zum Steg in Lisenen vorgespannt werden müssen. Über diese Verankerungsstellen werden in Hohlkastenbrücken grosse Kräfte konzentriert in die Stege, Boden- und Fahrbahnplatten eingeleitet. Im Sinne von Gewichtsreduktion des Brückenbauwerks sollen die Feldlisenen möglichst schlank und Platz sparend ausgeführt werden. Nur durch eine sorgfältige Bemessung und Konstruktion der Verankerungs- und Umlenkstellen kann die Voraussetzung für sichere und dauerhafte Brückenbauwerke gewährleistet werden. Die Bruchsicherheit ist dadurch nicht beeinträchtigt. Von grösstem Interesse ist jedoch die Gebrauchstauglichkeit, das heisst die Rissbreiten mit Rücksicht auf Korrosionsschäden in der Bewehrung. Bei den ersten in Deutschland extern vorgespannten Brücken schlug Prof. Eibl für den Stahl III vor, die Spannungen von 240 N/mm2 auf 220 N/mm2 zu begrenzen. In der Richtlinie für externe Vorspannung von 1998 wurden die Spannungen weiter auf 180 N/mm2 reduziert. Um eine unkontrollierte Rissbildung in den hoch bewehrten Verankerungskonstruktionen zu verhindern, sind genaue Kenntnisse der Kraftflüsse und für die Praxis taugliche Bemessungsmodelle notwendig. Die Geometrie und die statische Berechnung der gewählten Umlenkkonstruktion müssen entsprechend gewichtet werden. In dieser Arbeit werden an zwei Vergleichsmodellen, die lokalen Tragmechanismen einer extern vorgespannten Hohlkastenbrücke im Bereich der Feldumlenkstelle (Feldlisene) untersucht. Mit linear-elastischen und nichtlinearen numerischen Berechnungen wird abgeklärt, ob unter dem Ansatz einer Spannungserhöhung im Bewehrungsstahl auf 285 N/mm2, die Gebrauchstauglichkeit noch gewährleistet werden kann. Den Berechnungen wird eine Krafteinleitung von 2 x 3 MN mit Umlenkkräften von 4 x 0,64 MN zu Grunde gelegt. Die Berechnungen zeigen, dass das Ziel, mit einer Bewehrung von As = 3,35 % m2/m unter Gebrauchslasten keine Rissbreiten über 0,2 mm auftreten, erreicht werden kann. Die Berechnungen werden zudem an einem Brückenmodell im Massstab 1:1 in einem Belastungsversuch an der Empa in Dübendorf auf ihre Aussagekraft und Richtigkeit überprüft und bestätigt. / This present work which is aimed at contributing to local carrying mechanisms of a bridging box girder in the field of belt reversals, should be investigated and optimized. In designing a bridge the main concern is that of durability; especially in Germany and Switzerland, this is invariably acquiring a more central meaning. In this way recurring expenses can be reduced, whilst beyond these two countries in general more weight is laid on the rational manufacture and cost saving in the construction phases. The durability of externally pre-stressed bridges with their relatively low maintenance and service as well as repair costs are the main arguments for this method of construction. Larger anchorage construction is necessary for pre-tensioning external tensions. This is because the tensions are themselves not placed on the ligament itself, but must be pre-stressed in pilaster strips with a minimum distance. Over these anchorage locations immense energy is concentrated in the large box girder bridges, and thus induced in the ligament, ground and track supporting layers. As far as weight reduction of the bridging structure is concerned, the field pilaster strips should be designed as thin as possible and also be able to save space. Only through careful measuring and construction of the anchor and turning points can the requirements for safe and lasting bridge construction works be guaranteed. The bridge safety is thus not affected. However, the greatest interest is that of userfriendliness, i.e. the width of the fissure with consideration of corrosion damages in the armouring. At the first external pre-stressed bridge in Germany, Prof. Eibl suggested that for the steel III, stressing of 240/Nmm2 should be limited to 220 N/mm2. In the guideline for external pre-stressing of 1998, the tensions were further reduced to 180 N/mm2. In order to prevent an uncontrolled crack formation in the highly armoured anchorage construction, concrete knowledge of the distribution of forces for the applicable measurement models is necessary. The geometry and the statistical calculation of the selected deflect construction must be weighed accordingly. In this project two comparative models were inspected, which tested the local load mechanism of an external pre-stressed box girder bridge in the field redirecting area. With linear elasticity and numerical calculations it is possible to clarify if the serviceability can be allowed under the accretion of a stress increase in the armouring steel to 285 N/mm2. The calculations are based on a load transmission of 2 x 3 MN with a deviation force of 4 x 0,64 MN. The calculations will have a force transmission of 2 x 3 MN with turning forces of 4 x 0.64 MN forming the basis. The calculations portray that the goal to avoid any fissures over 0,2 mm can be achieved, with an armoring of As = 3,35 % m2/m under the service load. Additionally, the calculations will be assessed of their validity and accuracy on a scale of 1:1 in a loading test at the EMPA (the Swiss Federal Laboratories for Materials Testing and Research) in Dübendorf and be therefore confirmed.
182

Schoolbag carriage : design, adjustment, carriage duration and weight : a thesis presented in fulfilment of the requirements for the degree of Doctor of Philosophy in Ergonomics at Massey University, Palmerston North, New Zealand

Mackie, Hamish William January 2006 (has links)
There is anecdotal and scientific evidence to suggest that schoolbag carriage is associated with musculoskeletal discomfort (MSD) and possibly long-term back pain. Thus schoolbag carriage is an area of concern for students, parents and both education and health professionals. A schoolbag weight limit of 10% of body weight (BW) is currently recommended. However, it is based on subjective observations rather than objective findings and does not consider other aspects of schoolbag carriage such as schoolbag design and adjustment or carriage patterns. Five studies were conducted in order to determine the effects on students' responses to schoolbag carriage of schoolbag design, adjustment, carriage duration and weight. Backpack design had a significant effect on reported musculoskeletal discomfort and choice of backpack. Schoolbag hip-belt and shoulder strap adjustment and weight significantly affected shoulder strap tension forces and shoulder interface pressure in simulated schoolbag carriage. Using activity monitoring, school students were found to spend approximately two hours carrying their schoolbags each day. This usually comprised 11-15 times per day of 8-9 minutes of carriage. Using this temporal pattern information, 16 boys (13-14 years) were exposed to a simulated school day using schoolbags weighing 0, 5, 10, 12.5 and 15% BW and an additional condition of 10% BW with tighter shoulder straps. Posture, rating of perceived exertion (RPE), muscular strain and reported ability to walk and balance were significantly affected when schoolbag load reached 10% BW. However, despite these findings, the magnitude of self reported muscular strain and MSD suggested that 15% BW may be too heavy for school students. Thus, 10% BW may be an appropriate upper schoolbag weight limit for a typical school day. Using a psychophysical approach the mean (standard deviation) maximum acceptable schoolbag weight (MASW) selected by 16 school boys (13-14 years) was 10.4(3.8) %BW. This finding agrees with the findings of the previous study and supports the current schoolbag weight recommendation of 10% BW. The results of the five studies can be used in developing schoolbag carrying guidelines to help reduce the prevalence of MSD amongst school students.
183

Analytical study on the appraisal of communal land use management practices and policies towards climate resilience and sustainability in Bir-Temicha Watershed of the Upper Blue Nile Basin, Ethiopia

Tenaw Hailu Tedela 03 1900 (has links)
This study was aimed at analysing communal land use management practices and policies towards sustainability and climate resilience. The objectives of this study were to assess rainfall variability, climate change impact, adaptation practices and impediment factors for adaptation on the one hand and, on the other, analysing the pressure, scrutinising the sustainability of institutional practices, and assessing policy setting and its application status in managing communal lands. To conduct the study, a household survey, key informant interviews and group discussions were used. It employed both quantitative and qualitative methods. For analysis, rainfall variability trend analysis, different empirical formulas, Principal Component Analysis and analysis of variance were used. In addition, Qualitative Content Analysis technique and descriptive statistical tools were also used. The study found that there was spatiotemporal rainfall variability. About 18 extreme wet and 8 extreme dry events were depicted out of 194 frequencies of events. The most outstanding manifestations of climate change/variability impacts identified were: water scarcity, migration, severe erosion and feed scarcity. Applying biophysical measures on communal lands, practicing area enclosure and constraction of feeder road were moderately excersised adaptation and mitigation practices while, low level community awareness was the most outstanding barrier for community adaptation. Besides, feed source and fuel biomass energy did not satisfy community demand. Government recognition to support community user groups, the existence of community labour contribution and congruence between government legislation and community by-laws were found moderately strong. Besides, communal land administration and use of legislative setting and instruments to govern land administration were adequately in place to implement communal land use and management. However, workability of by-laws in applying them at the ground was a major weakness. In conclusion, the study revealed that there exist generally a weak communal land use management practices and policy implementation towards enhancing sustainability and climate resilience. Hence, the following recommendations were forwarded: enhancing community awareness, encouraging communities to establish their own private woodlots and grazing areas to reduce the pressure on communal land, applying proper communal land resource use and management plans and certifying communal lands with demarcation and maps should be given due emphasis to enhance sustainability. Moreover, policy and legislation evaluation and revision to improve its application at the ground is fundamental. On top of this, further research endeavour is still paramount important to scrutinize the integral effects of the biophysical, social, cultural and legislative dimensions for better sustainable and climate resilient communal land use management practices and policy implementation / College of Agriculture and Environmental Sciences / Ph. D. (Environmental Management)
184

The impact of surf tourism on the community of Tofino

Jefferies, Mervyn 20 November 2018 (has links)
This dissertation explores the emergence of surf tourism as a significant aspect of rural communities. It uses an inductive qualitative approach focused on Tofino, British Columbia, Canada as an example to provide an in-depth exploration of a rural community effected by this phenomenon. Qualitative interviews were conducted with a snowball sample of key informants to address the following research objectives: (1) What factors have influenced the evolution of surf tourism in Tofino; (2) How might the evolution of surf tourism in this case study relate to the Tourism Area Life Cycle (TALC); (3) What is the impact of surf tourism on the broader community development of Tofino? Analysis of the Tofino data elicited following themes: (1) For some, surfing is a desirable lifestyle, reflecting in some ways the concepts of specialization, serious leisure, and community’s identity; (2) Surf shops are a community hub for local surfers and surf tourists; (3) Pacific Rim National Park plays a critical role in the region, contributing to surfing and the surf tourism industry, but has yet to fully engage with surfers or the surfing industry; (4) New and more affordable equipment technology has brought increased access to cold-water surf and surf tourism, reducing what may have constrained the early development of surf tourism; (5) Considerable increases in the supply and demand for surfing in Tofino have occurred, tempered by the increased number of surfing competitions and other new tourism segments that exist in the community; (6) Increasing safety issues may undermine the growth of surf tourism; (7) Limits to surf tourism growth are evident regarding facility and physical carrying capacity; (8) As a result of the considerable growth of surfing in Tofino, recreational crowding, and conflict are in evidence, as are coping mechanisms; (9) ‘Localism’ exists in Tofino, but perhaps less so than in other destinations which have a fixed beach break; (10) Surf tourism has the potential for positive and negative impacts on First Nations communities in the region; and (11) Local government plays an important role. These themes were then analyzed and linked to the following theoretical concepts: serious leisure; specialization; leisure constraints; localism; violence; conflict; crowding, carrying capacity, amenity migration, the Tourism Area Life Cycle (TALC); and, rural tourism. This led to some intriguing findings. For example, unlike most other popular surf tourism destinations, crowding is not so apparent in the surf because the surf breaks in the Tofino area are primarily beach breaks that constantly shift as the bathymetry of the ocean floor changes with tides and currents, resulting in constant wave changes. This contrasts with fixed break conditions found elsewhere, so in Tofino it is easier to avoid other surfers by simply moving to another part of the wave. When the Tofino findings were compared with TALC, some similarities and differences were noted. Factors that appear to be consistent with the TALC model are: increasing numbers of tourists, changing type of tourists (e.g. more mass tourists, compared to the early days of surf tourism), increasing numbers of tourism facilities, increased levels of marketing, increased levels of interaction between visitors and local communities (perhaps leading to instances of conflict, and localism), and increased economic benefits to the community. However, one possible departure from the expected trajectory is impacts on the natural environment, which have increased in some ways, but are improved in other ways. There has been some environmental change in terms of the growth in the town of Tofino, and with the development of lodgings near to the surrounding beaches. However, much of the larger landscape, remains largely intact or less impacted than what might have occurred without the presence of Pacific Rim National Park, and the Clayoquot Biosphere Reserve. Further, the TALC model suggests that the development of tourism will lead to lesser local control of development. The Tofino findings suggest that there remains a great deal of local control and that local government support the tourism industry, including surf tourism. It was noted that the emerging surf tourism refers to several concepts found in the general nature tourism literature, such as crowding, conflict and carrying capacity, but the surf tourism literature tends to overlook the complexity of some of these concepts. For example, future surf tourism research might consider more explicit examination of the various dimensions of conflict described in this study, including in group and outgroup conflict, interpersonal conflict and social values conflict. There is little evidence of the incorporation of these concepts in the surf tourism literature. Finally, the data exposed a high level of social capital within the surf community and also between surfers and non-surfers as a facet of a close-knit rural community dependent to a degree on surf tourism as a social driver manifesting in mutual cooperation, trust and reciprocity occurring in social institutions such as surf-shops. / Graduate
185

Análise da sustentabilidade ambiental do uso e ocupação do solo no município de Ilha Comprida-SP

Jesus, Adriana Rita Guarnieri de 15 March 2002 (has links)
Made available in DSpace on 2016-06-02T20:00:53Z (GMT). No. of bitstreams: 1 5561.pdf: 4325885 bytes, checksum: 17098e745fb832216ed81c3a3af560d5 (MD5) Previous issue date: 2002-03-15 / Financiadora de Estudos e Projetos / The present work consisted in the application of a method for environmental sustainability analysis for land use and soil occupation of Ilha Comprida city, located in the southern state of São Paulo, the estuarine-lagoon complex Iguape-Cananéia- Paranaguá, region of Vale do Ribeira de Iguape. Land use and soil occupation of Ilha Comprida and the concept of sustainability as a theoretical, technical and empirical supporting body were studied. This work used a methodology based on a Method developed by a Study Group from UFSCar (Federal University of São Carlos) called Strategic Planning and Sustainable Urban Environment (PESMU), which incorporates the sustainability issue in the analysis and evaluation of urban context projects. Therefore, the methodology makes use of flow charts, interaction matrices, characterization sheets, used together, directing the analysis of environmental sustainability in the city, pointing favorable, neutral or unfavorable trends to environmental sustainability. Practical applications of the method in different areas of the city were carried out, showing the land use and soil occupation as the action variable (street construction layout, plot, deployment of building plots, urban uses and buildings geometries) and environmental issues as control variables. Comprising an easy applicability methodology, it proved to be feasible, and can be added other possible information and more complex analysis tools to enable the expansion of its applicability. / O presente trabalho se constituiu na aplicação de um método para análise da sustentabilidade ambiental do uso e ocupação do solo do Município de Ilha Comprida, localizado no extremo sul do estado de São Paulo, no Complexo estuarino-lagunar de Iguape-Cananéia-Paranaguá, região do Vale do Ribeira de Iguape. Para tanto foram estudados: o uso e ocupação do solo do município de Ilha Comprida e o conceito de sustentabilidade como corpo de sustentação teórico, técnico e empírico. No presente trabalho, é feita a utilização de uma metodologia baseada em um Método desenvolvido pelo Grupo de estudos em Planejamento Estratégico e Sustentável do Meio Urbano (PESMU) da UFSCar, o qual incorpora a questão da sustentabilidade na análise e avaliação de projetos no contexto urbano. Assim, a metodologia faz uso de fluxogramas, matrizes de interações, fichas de caracterizações, utilizadas conjuntamente, direcionando a análise da sustentabilidade ambiental do Município, apontando tendências favoráveis, desfavoráveis ou neutras à sustentabilidade ambiental. Foram realizadas aplicações práticas do método em diferentes áreas do município, evidenciando o uso e ocupação do solo como a variável de ação (arruamento, lote, implantação de loteamentos, usos urbanos e geometrias das edificações) e os aspectos ambientais como as variáveis de controle. Compreendendo uma metodologia de fácil aplicabilidade, mostrou-se viável, podendo ser introduzidas eventuais informações e instrumentos mais complexos de análises que possibilitem a ampliação da sua aplicabilidade.
186

Planejamento turístico - recreativo dos ambientes recifais das praias dos Seixas , Penha e Arraial (PB) / Touristic-recreational planning of reef environments at the beaches of Seixas, Penha, and Arraial, in Paraíba State

Melo, Rodrigo de Sousa 21 February 2006 (has links)
Made available in DSpace on 2015-05-07T14:49:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-02-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Reef environments attract yearly, a huge influx of tourists and recreationists who relentlessly pursue the leisure and knowledge of marine biodiversity, generating a significant profit for the economy of locales with peculiarities for tourism and recreation. However, the touristicrecreational activity at environmental reefs presents negative implications for local biodiversity if not associated to a planned process, mainly when not interrelated to social, economical, and biological dimensions throughout the planning. The reef environments at the beaches of Seixas, Penha, and Arraial (on southern littoral of João Pessoa, capital of Paraíba state, Northeast Brazil) have a lower touristic-recreational influx as compared to other reefs in the state of Paraíba. However, there is already a timid touristic promotion advertising the reefs of that part of southern littoral of Paraíba, mostly the ones at Penha beach. Therefore, it was aimed in the present dissertation to present a proposal concerning tourism planning and recreation on environmental reefs situated at the above-mentioned beaches, through zoning and evaluation of recreational carrying capacity. Firstly, it was performed a diagnosis of the areas by focusing socio-economic and biological aspects that generated important information for constructing the zoning proposal and estimating the recreational carrying capacity (Cifuentes, 1992). With respect to the biological aspects, it was performed an analysis of the distribution of the cnidofauna (with emphasis on scleractinian corals, zoanthidean, and calcareous hydroids) in areas with and without recreational use, through visual records carried out in October and November 2005. With respect to the socioeconomical aspects, the artisanal fishermen s way of life at the Penha beach was characterized, as well as their perceptions on several subjects, like the reef environments, conservation units, and excluded zones for fishing and tourism, by applying structured interviews as data collection technique which was carried out in June and July 2005. The following cnidarians species were identified: five scleractinians (Siderastrea stellata, Mussismilia harttii, Montastrea cavernosa, Agaricia agaricites and Porites astreoides; four zoanthideans (Palythoa caribaeroum, Protopalythoa variabilis, Zoanthus sociatus, and Zoanthus nymphaeus); and one calcareous hydroid (Millepora alcicornis). A greater biodiversity was observed in the area without recreational use. The fishermen at the Penha beach usually go to the reef areas for fishing and leisure, and they showed to be receptive to tourism and to the proposal for the establishment of a conservation unit in the area. Four zone types were defined for the zoning, with distinct uses and patterns, besides a buffer zone adjacent to the continent, since indirect impacts caused by local human actions may reduce the reefs health. The recreational carrying capacity was established from 26 visits per day or 4,680 per year carried out to the reefs of Seixas beach. It is proposed here a flexible and adjustable touristic-recreational planning for the study area, which might be partly modified throughout time, as new data on local biota, physicochemical parameters, and increase of touristic-recreational influx may come out / Os ambientes recifais atraem, anualmente, um contingente de turistas e recreacionistas ávidos pelo divertimento e conhecimento da biodiversidade marinha, gerando um aporte financeiro significativo para as economias de locais com peculiaridades para o turismo e recreação. No entanto, a atividade turístico-recreativa em ambientes recifais reveste-se de um caráter destrutivo para a biodiversidade local quando desvinculado de um processo de planejamento, sobretudo quando não interrelaciona as dimensões sociais, econômicas e biológicas no transcorrer do planejamento. Os ambientes recifais das praias dos Seixas, Penha e Arraial (litoral sul da cidade de João Pessoa-PB) possuem um fluxo turísticorecreativo inferior ao de outros ambientes recifais da Paraíba. No entanto, já existe uma tímida promoção turística divulgando os recifes da área, sobretudo os da Penha. Assim, o objetivo desta dissertação foi o de apresentar uma proposta de planejamento do turismo e da recreação para os ambientes recifais das praias acima mencionadas, através do zoneamento e da avaliação da capacidade de carga recreativa. Num primeiro momento, o diagnóstico das áreas de estudo fez-se necessário, enfocando aspectos biológicos e sócioeconômicos, que geraram subsídios para a construção da proposta de zoneamento e para a determinação da capacidade de carga recreativa. Com respeito aos aspectos biológicos, foi realizada uma análise da distribuição da cnidofauna (com ênfase nos corais escleractínios, zoantídeos e hidróides calcários) em áreas com e sem uso recreativo, através de registro visual, nos meses de outubro e novembro de 2005. Quanto aos aspectos sócio-econômicos, o modo de vida dos pescadores artesanais da Penha foi caracterizado, bem como suas percepções sobre diversos assuntos, como ambientes recifais, unidades de conservação, zonas de exclusão de pesca e o turismo, utilizando a entrevista estrutura como técnica de coleta de dados, nos meses de junho e julho de 2005. Foram identificadas cinco espécies de corais escleractínios (Siderastrea stellata, Mussismilia harttii, Montastrea cavernosa, Agaricia agaricites e Porites astreoides; quatro de zoantídeos (Palythoa caribaeroum, Protopalythoa variabilis, Zoanthus sociatus, e Zoanthus nymphaeus); e um hidróide calcário (Millepora alcicornis). A maior biodiversidade foi observada na área sem uso recreativo. Os pescadores da Penha utilizam os ambientes recifais para o lazer e a pesca, e se mostraram receptivos ao turismo e a proposta de criação de uma unidade de conservação na área de estudo. Para o zoneamento foram definidos quatro tipos de zonas, com usos e padrões distintos, e uma zona de amortecimento na porção terrestre adjacente, pois os impactos indiretos provocados pela ação humana podem diminuir a saúde dos recifes. A capacidade de carga recreativa foi definida em 26 visitas/dia ou 4.680 anuais para o ambiente recifal da praia dos Seixas. Propõe-se aqui um planejamento flexível, ajustável e passível de ser modificado, ao longo do tempo, com o advento de dados referentes à biota local, aos parâmetros físico-químicos e ao aumento do fluxo turístico-recreativo
187

?Caracteriza??o limnol?gica e determina??o da capacidade suporte do reservat?rio mendubim, (Rio Grande do Norte) para o cultivo de peixes em tanques-rede

Rocha, Ana Catarina de Lima 03 July 2008 (has links)
Made available in DSpace on 2014-12-17T14:01:57Z (GMT). No. of bitstreams: 1 AnaCatarinaLR.pdf: 1581949 bytes, checksum: d36f953346d69da5932504873625ff62 (MD5) Previous issue date: 2008-07-03 / ?The aims of this study were: i) assessing the trophic state of the Mendubim reservoir (semi-arid, Rio Grande do Norte, Brazil; 05? 38 99,0 S 36?55 98,0 W) based on chlorophyll-a, total phosphorus and nitrogen concentrations and water transparency; ii) relating the patterns of temporal variation of zooplankton and phytoplankton to the trophic state of the reservoir and iii) investigating the carrying capacity of the reservoir for cage fish farming. The samplingwas done monthly from July 2006 to July 2007 in three stations at the reservoir: next to the dam (barrage), in the central region and in the mouth of the main tributary. The abiotic and biotic variables analyzed were: Secchi depth, volatiles and fixed suspended solids, chlorophyll-a, total phosphorus and nitrogen, TN:TP ratio and mesozooplankton and phytoplankton composition and biomass. The results showed that the reservoir can be considered as mesotrophic with mean concentrations of total nitrogen, phosphorus and chlorophyll-a equal to 1711, 1 ?g.L-1, 30,8 ?g.L-1 and 5,62 ?g.L-1 respectively. The Cyanophyceae class was the most representative in terms of density, with the presence of potentially toxic species such as Microcystis aeruginosa, Planktothrix planctonica, Cylindrospermopsis raciborskii, Aphanizomenon sp. ,Aphanocapsa delicatissima and Pseudanabaena acicularis. Among the zooplankton, the genus Notodiaptomus presented the largest biomass values. Overall, our results show that the light limitation should explain the weak relationship between chlorophyll-a and total phosphorus and nitrogen concentrations. We concluded that the water of Mendubim reservoir is suitable for intensive fish cage aquaculture. Based on the carrying capacity calculations for this reservoir, we found that the maximum sustainable yield of tilapias in cages in the reservoir is 126 ton per year assuming a factor of food conversion of 1.5: 1.0 and a phosphorus content in the fish food of 1% / ?Os objetivos do presente estudo foram: i) avaliar o estado tr?fico do reservat?rio Mendubim (semi-?rido, Rio Grande do Norte, Brasil; 05? 38 99,0 S 36?55 98,0 W ) com base nas concentra??es de clorofila-a, f?sforo e nitrog?nio total, e na transpar?ncia da ?gua; ii) relacionar os padr?es de varia??o temporal da composi??o e biomassa do fitopl?ncton e zoopl?ncton ?s varia??es do estado tr?fico do reservat?rio e iii) investigar a capacidade de suporte do reservat?rio para o desenvolvimento de atividades de piscicultura em tanques-redes. Para tanto, foram realizadas amostragem mensais no per?odo de julho/2006 a julho/2007 em tr?s pontos de coleta, sendo um pr?ximo ? barragem, outro na regi?o central do reservat?rio e o terceiro na desembocadura do principal tribut?rio. As vari?veis bi?ticas e abi?ticas analisadas foram: profundidade e transpar?ncia da coluna d??gua, concentra??es de s?lidos fixos e vol?teis em suspens?o, clorofila-a, nitrog?nio e f?sforo total, raz?o NT:PT, composi??o e biovolume do fitopl?ncton, composi??o e biomassa do mesozoopl?ncton. Os resultados obtidos mostraram que o reservat?rio em estudo pode ser considerado mesotr?fico com concentra??es m?dias de nitrog?nio total, f?sforo total e clorofila-a igual a 1711,1?g l-1 , 30,8 ?g l-1 e 5,62 ?g l-1 respectivamente. A classe Cyanophyceae foi a de maior representatividade em termos quantitativos, com a presen?a de esp?cies potencialmente t?xicas, tais como Microcystis aeruginosa, Planktothrix planctonica, Cylindrospermopsis raciborskii, Aphanizomenon sp., Aphanocapsa delicatissima e Pseudanabaena acicularis. Quanto ? comunidade zooplanct?nica, o g?nero Notodiaptomus, foi o que apresentou maiores valores de biomassa. De um modo geral, os resultados encontrados mostram que a limita??o do crescimento algal por luz, ? uma poss?vel explica??o para as fracas rela??es entre as concentra??es de clorofila-a e de f?sforo e nitrog?nio total no ambiente. Com isso, conclu?mos que as ?guas do reservat?rio Mendubim se encontram apropriadas para a produ??o de pescado num regime intensivo de cultivo em tanques-rede. Com base nos c?lculos da capacidade de suporte do ambiente, verificamos que a produ??o m?xima sustent?vel de til?pias em tanques-rede no reservat?rio ? da ordem de 126 toneladas por ano assumindo um fator de convers?o alimentar de 1,5:1,0 e um conte?do de f?sforo na ra??o de (1,0%)
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Proposta de modelagem da capacidade de suporte hídrica para o estado de São Paulo, Brasil / Proposal of hydric carrying capacity modeling for the state of São Paulo, Brasil

Mello, Silas Volpon de [UNESP] 18 August 2017 (has links)
Submitted by Silas Volpon de Mello (silasmelloo@gmail.com) on 2017-09-18T16:07:04Z No. of bitstreams: 1 Dissertação_Mestrado_deMello_SV.pdf: 6481861 bytes, checksum: bfe9dc719b21419babdfc049e7b8ece6 (MD5) / Approved for entry into archive by Monique Sasaki (sayumi_sasaki@hotmail.com) on 2017-09-19T20:02:38Z (GMT) No. of bitstreams: 1 mello_sv_me_bauru.pdf: 6481861 bytes, checksum: bfe9dc719b21419babdfc049e7b8ece6 (MD5) / Made available in DSpace on 2017-09-19T20:02:38Z (GMT). No. of bitstreams: 1 mello_sv_me_bauru.pdf: 6481861 bytes, checksum: bfe9dc719b21419babdfc049e7b8ece6 (MD5) Previous issue date: 2017-08-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este texto apresenta uma pesquisa que propõe um modelo para calcular a Capacidade de Suporte Hídrica (CSH) de regiões urbanizadas visando o Desenvolvimento Sustentável, principal objetivo da humanidade neste século. Utilizando as Análises Estocásticas de Fronteira como ferramenta de modelagem da capacidade de suporte, juntamente com o auxílio de um sistema de informações geográficas (SIG), foi criado um método para calcular a carga antrópica no meio ambiente, ou seja, calcular a intensidade de solicitação ou estresse sobre os recursos naturais que uma dada região exerce sobre seu meio. Um estudo exploratório foi elaborado para verificar a viabilidade desta proposta e posteriormente um modelo específico foi desenvolvido, utilizando variáveis de natureza hídrica, culminando no cálculo da CSH dos municípios e das Unidades de Gerenciamento de Recursos Hídricos (UGRHI) do estado de São Paulo. A disponibilidade hídrica superficial dos objetos de estudo, uma das variáveis hídricas que compõe o modelo, foi calculada de forma aproximada utilizando a nova proposta de regionalização de vazões para o estado de São Paulo, onde foi criado o primeiro banco de dados que agrega informações sobre as vazões Q95, Q7,10 e Qm para todos os municípios do estado.Na sequência, foram simulados três cenários abordando possíveis construções do modelo CSH, dois deles consideraram diferentes formas de agrupamento dos parâmetros e o terceiro obteve as classificações de suporte hídrico para as UGRHIs a partir dos resultados dos municípios. O primeiro cenário apontou 5 UGRHIs e 213 municípios em potencial déficit hídrico e o segundo apontou 6 UGRHIs e 180 municípios nesta mesma situação. O terceiro cenário apontou 7 UGRHIs em potencial déficit no suprimento da demanda de água. A partir dos resultados, foram apontadas regiões que estão sob potencial estresse hídrico, ou seja, que não conseguem fornecer de maneira sustentável a quantidade de água requerida por seus habitantes. Essas regiões podem ser apontadas como as mais vulneráveis em períodos de seca. Assim, pretende-se disponibilizar um modelo para auxiliar na questão da preservação do meio ambiente nas escalas local e regional, considerando-se a disponibilidade de água. / This work presents a research project that proposes a model to calculate the Hydric Carrying Capacity (HCC) of urbanized areas aiming at the Sustainable Development, the main goal of humanity in this century. Using Stochastic Frontier Analysis (SFA) as a modeling technique for carrying capacity along with geographic information systems (GIS), a method to calculate the anthropic load in the environment was created. In other words, the idea was to calculate the stress intensity on the natural resources that a given region produces on its environment. An exploratory study was carried out to verify the feasibility of this proposal and later a specific model was developed. Using hydric variables, the model resulted in the determination of the HCC for the municipalities and for the Water Resources Management Units (UGRHI) of the State of São Paulo. The surface water availability of the objects of study, which is one of the hydric variables that compose the model, was calculated in an approximate way using the new proposal of regionalization of flows for the state of São Paulo. This resulted in the first database that aggregates information about the flows Q95, Q7,10 and Qm for all municipalities in the state. Three scenarios were simulated, discussing possible constructions of the HCC model. Two of them considered different ways of grouping the parameters and the third one obtained the hydric support classifications for the UGRHIs from the results of the municipalities. The first scenario pointed out 5 UGRHIs and 213 municipalities in potential hydric deficit, while the second pointed to 6 UGRHIs and 180 municipalities in this same situation. The third scenario pointed out 7 UGRHIs in potential deficits in supplying water demand. From these results, regions that are under potential water stress were pointed out, that is, regions that cannot provide the amount of water required by their inhabitants in a sustainable way. These regions can be identified as the most vulnerable in periods of drought. Thus, the idea was to provide a model as an aid for the environment preservation at both local and regional scales, considering the availability of water.
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Uso do espaço e seleção de hábitat pelo Mico-Leão-da-Cara-Preta (Leontopithecus caissara) / Space use and habitat selection by the Black-faced Lion Tamarin (Leontopithecus caissara)

Alexandre Túlio Amaral Nascimento 20 June 2008 (has links)
Comprometida com a compreensão da relação entre hábitat e uso do espaço pelo mico-leão-da-cara-preta (Leontopithecus caissara), esta dissertação se norteia por três perguntas: Diferenças de hábitat entre ilha e continente influenciam o tamanho da área de vida? Há predileção da espécie por alguma classe de vegetação dentro da área de uso? Qual a capacidade suporte em sua área de ocorrência continental, bem como nas áreas potenciais para seu manejo conservacionista? Na tentativa de elucidar essas questões esta dissertação se divide em três capítulos. O primeiro contextualiza o trabalho e a apresenta o estado atual de conhecimento de L. caissara. Os capítulos segundo e terceiro concernem às questões centrais do trabalho - uso e seleção do hábitat pelo mico-leão-da-cara-preta. No capítulo dois apresentamos o uso do espaço pela espécie em sua região continental de ocorrência e comparamos os resultados obtidos com as informações disponíveis para a Ilha do Superagui. No capítulo três tratamos da seleção do hábitat por grupos insulares e continentais de L. caissara e estimamos a capacidade suporte para a espécie considerando seus limites de ocorrência e as áreas passíveis de receber animais em situação de manejo. Ao final desses capítulos apresentamos algumas considerações e recomendações para pesquisa e conservação do mico-leão-da-cara-preta. A preocupação com uma postura crítica e construtiva acerca das metodologias de estudos e análises sobre uso do espaço por espécies animais é transversal aos assuntos tratados ao longo de todo o trabalho. Os resultados apresentados confirmam as grandes áreas de vida de L. caissara, as quais parecem ser compensadas energeticamente pela incorporação de novas áreas e abandono de outras ao longo do tempo. Os tipos de hábitats mais intensamente utilizadas pelos mico-leão-da-cara-preta intercalaram áreas de floresta madura e em clímax edáfico com áreas antropizadas em sucessão, ambos hábitats sobre pouco desnível altimétrico. A capacidade suporte estimada é aparentemente incapaz de sustentar uma população viável e ressalta a urgência de pesquisas genéticas que colaborem para a compreensão do histórico ecológico/evolutivo de L. caissara. Potenciais translocações com vistas ao aumento populacional devem considerar as amplas áreas de diva, a espacialidade dinâmica, a relação uso/disponibilidade do hábitat e as diferenças entre ilha e continente. / This dissertation focuses on the interaction between habitat and space use by the black-faced lion tamarin (Leontopithecus caissara). We seek to answer three questions: 1) Do differences in vegetation between insular and continental habitats influence how the species use the space? 2) Does the species prefer a specific type of vegetation within its home-range? 3) What is the carrying capacity of the continental distribution and which are areas for potential conservation management? The first chapter of this dissertation relates the subjects discussed and introduces what is known about L. caissara. The second and third chapters develop the central questions of the research: the use and selection of habitat by the black-faced lion tamarin. In Chapter Two, we introduce space use by the species in its continental distribution and compare the results with data from Superagui Island. In Chapter Three, we address habitat selection by insular and continental groups of L. caissara and estimate the carrying capacity for the species given its distribution and areas potentially able to receive animals in a management context. The conclusion of each chapter presents considerations and recommendations for research and conservation. The study methods and analyses of space use aim to be critical and constructive and are relevant to the topics addressed throughout the text. The results presented confirm that the large home-ranges of L. caissara undergo dynamic turnovers, with some areas being abandoned and others incorporated throughout the year. The habitat types most intensively used by tamarins include areas of mature and forest mixed with areas of anthropic succession, both occurring at low altitudes. The estimated carrying capacity is apparently insufficient to maintain a viable population and highlights the importance of genetic studies that incorporate the ecological/evolutionary history of the species. Potential translocations meant to increase population size should consider the large home-ranges, dynamic spatial structure, relation of habitat use/availability and the differences between island and continent.
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Wachstum, Pinningeigenschaften und Granularität von dicken YBa2Cu3O7-δ-Schichten auf texturierten metallischen Substraten

Pahlke, Patrick 13 March 2018 (has links) (PDF)
In der vorliegenden Arbeit wurden Schichten des Hochtemperatursupraleiters YBa2Cu3O7-δ (YBCO) untersucht, die epitaktisch mittels gepulster Laserabscheidung auf texturierten metallischen Templaten abgeschieden wurden. Dabei kamen ionenstrahltexturiertes ABAD-YSZ-Band und walztexturiertes NiW-Band zum Einsatz. Für Anwendungen solcher sogenannten Bandleiter ist die Fähigkeit zum Transport möglichst hoher kritischer Ströme Ic essentiell. Dies kann durch das Wachstum möglichst dicker Schichten, eine Verbesserung der Flussschlauchverankerung (Pinning), sowie die Reduzierung der durch Korngrenzen verursachten Stromlimitierung erreicht werden. Im ersten Teil der Arbeit wurden strukturelle und supraleitende Eigenschaften in bis zu 5 µm dicken YBCO-Schichten auf ABAD-YSZ-Band untersucht. Dazu wurden neben nicht-fremdphasendotierten (undotierten) YBCO-Schichten auch BaHfO3- und BaY(NbTa)O6-dotierte YBCO-Schichten herangezogen. Die Untersuchungen erfolgten mittels Röntgenbeugungs-methoden (XRD), Rasterelektronen- und Rasterkraftmikroskopie (REM, AFM), sowie resistiver und induktiver Methoden zur Bestimmung der Sprungtemperatur Tc und der kritischen Stromdichte Jc. Schichtdickenabhängige Messungen konnten u. a. zeigen, dass Ic in undotierten YBCO-Schichten bei einer Dicke oberhalb von 2,8 µm nicht weiter anstieg, während Ic in den dotierten Schichten bis zu einer Dicke von 5 µm nicht limitiert war. Darüber hinaus konnte in temperatur- und feldabhängigen Jc-Messungen ein verbessertes Pinningverhalten bei tiefen Temperaturen und in hohen äußeren Magnetfeldern gefunden werden. Mit Hilfe von transmissionselektronenmikroskopischen Untersuchungen (TEM) und Messungen der Jc-Anisotropie wurde zusätzlich ein Strukturschema herausgearbeitet, das eine Verknüpfung von Herstellungsparametern, Mikrostruktur und Pinningeigenschaften ermöglicht. Der zweite Teil befasste sich mit der Analyse der Mikrostruktur und der lokalen Textur von undotierten YBCO-Schichten auf ABAD-YSZ- und NiW-Band. Die lokale Textur wurde dabei mittels Rückstreuelektronenbeugung (EBSD) aufgelöst. Die Ergebnisse wurden mit orts-aufgelösten Magnetisierungsmessungen (Raster-Hall-Sonden-Mikroskopie) korreliert, mit denen der lokale Stromfluss untersucht werden kann. Auf beiden Templaten zeigte sich eine granulare Struktur, die durch gegeneinander verkippte bzw. verdrehte YBCO-Körner gekennzeichnet war. Während die granulare Struktur auf ABAD-YSZ-Band durch hauptsächlich in-plane missorientierte YBCO-Bereiche mit einem Durchmesser < 1 µm charakterisiert war, konnten auf NiW-Band hauptsächlich out-of-plane missorientierte Bereiche mit einer typischen Größe von 20-50 µm nachgewiesen werden. Auf NiW-Band hing die YBCO-Mikrostruktur und die Schärfe der lokalen Textur von der individuellen out-of-plane Missorientierung des darunter-liegenden NiW-Korns ab, was auf eine bereits im unbeschichteten NiW-Band vorhandene Facettierung zurückgeführt werden konnte. Zu deren Beschreibung wurde ein Facettenmodel entwickelt, das durch TEM-Untersuchungen bestätigt werden konnte. Abschließend wurde auf einkristallinen Substraten und auf ABAD-YSZ-Band ein homogener Stromfluss nachgewiesen, während die supraleitenden Eigenschaften in YBCO-Schichten auf NiW-Band von der lokalen Mikrostruktur und Textur bestimmt wurden. Damit konnte gezeigt werden, dass die globalen Eigenschaften der Bandleiter vom Zusammenspiel eines über Korngrenzen miteinander verbundenen Ensembles von Körnern mit individuellen Eigenschaften bestimmt werden.

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