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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

Influence of biomass burning aerosol on land-atmosphere interactions over Amazonia

Zhang, Yan 18 July 2005 (has links)
The impacts of biomass burning smoke on local rainfall and the structure of the atmospheric boundary layer have been actively studied in recent years. However, whether the large-scale biomass burning in the later dry season over Amazonia Region could influence the dry-to-wet transition season have not been examined. Previous observations have shown that the substantial increase of rainfall from dry to wet season over Amazonia are actually caused by small changes of the atmospheric thermodynamic structure relative to those over other monsoon regions. Consequently, the onset date of wet season can vary greatly as influenced by external or internal anomalous forcings. Thus, it is possible that the transition of the atmospheric thermodynamic structure and circulation from dry to wet season is also sensitive to the impacts of biomass burning smoke. To test this hypothesis, we have forced RegCM3 model with direct radiative forcing of smoke inferred from MODIS for the transition season (August to November). The comparison with control run helps us to examine the direct and semi-direct influences of smoke on the transition from dry to wet season. Our preliminary results show that the direct and semi-direct forcings of smoke could significantly influence the rainfall and related atmospheric and land surface conditions during the transition. However, these changes are sensitive to the prescribed vertical distribution of the aerosols.
22

Temporal and spatial analysis of suspended sediment distribution in the Amazon River using satellite imagery

Park, Edward 30 October 2013 (has links)
Patterns of surface sediment concentration distribution in rivers are significant for understanding the broad ranges of fluvial environmental systems. In the case of the Amazon Basin, the complexity in the sediment pattern distribution is affected by the anabranching channel pattern of the Amazon River, the input by tributaries (some of which are among the largest rivers on earth) and the existence of huge and complex floodplains. Until recently, the assessment of sediment fluxes has been concentrated on hydro-sedimentological techniques in the Amazon Basin; however, efforts on characterizing the patterns of sediment transport have been neglected. This study aims to improve the understanding of the pattern of sediment distributions over a large scale in the Amazon River by estimating surface sediment concentration with remote sensing techniques. Field acquired surface sediment concentration values were supplied from three gauging stations representing the upstream, midstream and downstream sections of the Amazon River from 2000 to 2010 and calibrated with MODIS surface reflectance products (N=207, 232, 313, respectively). Empirical models were derived with robust causalities (0.63<R2<0.92) between field surface sediment concentration and surface reflectance from each station; however, sensitivity of reflectance around each stations were shown to be significantly affected by the local hydrological behaviors, leaving implications on analysis of the geomorphic characteristics affecting these associations. Overall, the capability of the remote sensing-based platform introduced in this study is successfully demonstrated by capturing the spatial and temporal variability of surface sediments in the Amazon River Basin, which is the largest and the most complex river system on earth. / text
23

Marketing Mysticism and the Purchase of Pilgrimage: The Rise of Spiritual Tourism in Cusco and Iquitos, Peru

Owen, Bonnie Jean January 2006 (has links)
This thesis presents my findings on the Peruvian spiritual tourism industry in both Cusco and Iquitos, based on six weeks of fieldwork during Summer 2005. New Age and Peruvian spiritual belief systems have converged to form current Andean mystical and Amazonian shamanic practices. Increasing numbers of foreign tourists, whether believers in the New Age or not, are coming to gain a deeper understanding of these spiritual belief systems through participation in sacred rituals and ceremonies. The effects of such tourism are similar to other cultural tourism industries, such as increased competition, matters of authenticity, and performance of culture. Other issues are more specific to the spiritual tourism industry, such as the physical and sexual exploitation of tourists. But there are also many positive outcomes of this spiritual interchange, such as individual physical, mental, and emotional healing.
24

Satellite-derived tropospheric ozone measurements over the amazon basin and proposed causes of interannual variability

Morris, Nyasha Monique 08 1900 (has links)
No description available.
25

The behavioural and evolutionary ecology of Corydoras adolfoi and Corydoras imitator : studies on two sympatric species of catfishes from a small tributary of the Upper Rio Negro, Brazil (Pisces, Siluriformes, Callichthyidae)

Sands, David Dean January 1994 (has links)
No description available.
26

The woody flora and soils of seven Brazilian Amazonian dry savanna areas

Sanaiotti, Tania Margarete January 1996 (has links)
This study compares the soils, floristic composition, phytosociological structure and history of seven Brazilian savannas in the Amazon basin: those at Alter do Chao, Amapa, Roraima and SE Humaita are islands in rain forest; and those at Chapada dos Parecis, Redencao, and Carolina are on the periphery (northern border) of the central Brazilian savannas (the so-called 'cerrado'). A total of 26 transects were sampled by the PCQ method (for trees with dbh greater than or equal to 5 cm) and additional tree species were recorded by 'wide patrolling'. A total of 101 species were recorded from the transects and another 43 species were recorded by 'wide patrolling'. Byrsonima crassifolia, B. coccolobifolia, Curatella americana, Salvertia convallariodora and Plathymenia reticulata occurred in most or all sites, but no species occurred in all transects. The number of species in the isolated savannas decreased with the distance from the central Brazilian core savanna area. Both cluster analysis (based on the S0rensen Similarity Index) and ordination (DCA), showed that the disjunct and non-isolated peripheral areas were in floristically distinct groups. Five surface soil samples (0 - 10 cm) were collected from each of the 26 transects. Two soil cores (up to 4 m depth), one located in the savanna and the other from the nearest forest present, were taken from each study site for carbon isotope analysis. All the sites had acidic soils (pH 4.5 - 5.2) and a wide range of concentrations of aluminium (0.12 - 1.49 meq 100g-1); most of the other soil properties varied significantly within study sites. An ordination (PCA) distinguished the soils from Amapa, Alter do Chao, Redencao and Roraima, but did not distinguish the disjunct sites from non-isolated peripheral ones. The soil delta 13C values of all the disjunct savannas indicated a vegetation change in the past from C3 to C4 plants, showing that forest (or at least a vegetation with few C4 plants) formely covered these sites. 14C dating indicated that the disjunct savannas are of relatively recent origin, e.g. Humaita was dated at about 2,000 years BP, and hence that they are not remnants of a more widespread Pleistocene savanna in the Amazon.
27

A comunidade de pesquisa da Região Norte do Brasil : perspectivas sobre o papel da ciência na construção do desenvolvimento sustentável / The application of geotechnologies in the management of the sustainable development reserve Mamiraua : perspectives about the role of science in building a sustainable development

Nonato, Josimara Martins Dias 26 June 2012 (has links)
Orientador: Newton Muller Pereira / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Geociências / Made available in DSpace on 2018-08-21T09:02:21Z (GMT). No. of bitstreams: 1 Nonato_JosimaraMartinsDias_D.pdf: 4871772 bytes, checksum: 924e329b362b4d3ada37d918f07aa2e1 (MD5) Previous issue date: 2012 / Resumo: A complexidade das questões sociais contemporâneas, tal como a problemática da conservação ambiental, convoca a ciência ao exercício da democracia. Nesse sentido, a presente Tese analisa as características e as perspectivas da comunidade de pesquisa da região Norte do Brasil em relação aos pressupostos de um Desenvolvimento Sustentável socialmente justo, considerando a participação das populações tradicionais residentes no interior ou nas proximidades de áreas protegidas da Amazônia. Essa análise pauta-se pelos pressupostos teóricos, confirmados ao longo da pesquisa, de que o conhecimento científico é socialmente construído, indissociável do contexto geográfico e, consequentemente, não é neutro. Para a compreensão das especificidades da comunidade de pesquisa em questão, a Tese resgata a formação histórica da ciência na Amazônia desde o período colonial e detalha a atual configuração da produção técnico-científica nos estados da região. Além desse panorama, foram aplicados questionários para uma amostra estratificada de líderes de grupos de pesquisa em todos os estados da região Norte (Amazonas, Pará, Acre, Rondônia, Roraima e Tocantins) e também entrevistas presenciais. Assim, a análise das perspectivas nas respostas dos pesquisadores considerou os traços históricos da ciência na região, os pressupostos do Desenvolvimento Sustentável, as atuais disparidades intra-regionais de recursos disponíveis para a produção técnico-científica e as diferentes áreas de conhecimento científico. Tal análise explicita e conclui que, para além de maiores investimentos em ciência e tecnologia, o processo de Desenvolvimento Sustentável socialmente justo demanda uma nova política de produção do conhecimento científico e de concepção das inovações tecnológicas através do reconhecimento das diferentes matrizes de saberes que fazem parte do contexto da região Norte / Abstract: The complexity of contemporary social issues, such as the issue of environmental conservation, calls the science to practice the democracy. In this context, the present Thesis analyzes the characteristics and prospects of the researched community in the Northern Region in Brazil in relation to the assumptions of a Sustainable Development socially fair, considering the participation of traditional populations living within or near of protected areas in the Amazon. This analysis is guided by theoretical assumptions, confirmed during the research, that scientific knowledge is socially constructed, inseparable from the geographical context and therefore is not neutral. To understand the specifics of the researched community, the Thesis brings the historical development of science in the Amazon since the colonial period and details the current configuration of the technical-scientific production in the states of the region. Beyond this perspective, questionnaires were applied in a stratified sample of leading research groups in all states of Northern Region (Amazonas, Para, Acre, Rondônia, Roraima and Tocantins) and also face to face interviews. Thus, the analysis of the implicit perspectives in the answers of researchers considered traces of historical science in the region, the assumptions of Sustainable Development, the current intra-regional disparities in available resources to the technical-scientific production and the different areas of scientific knowledge. This analysis explained that, over there more investment in science and technology, the process of Sustainable Development socially fair demands a new politics of scientific knowledge production and a conception of technological innovation through the recognizing of different matrices of knowledge that are part of the Northern Region context / Doutorado / Politica Cientifica e Tecnologica / Doutora em Política Científica e Tecnológica
28

Scalability and Economy of Amazon Lambda, EKS, and ECS

Altaleb, Bashar, Abo Khalaf, Muhamed kheer January 2022 (has links)
Cloud computing is the current need and the futuristic strategy of many businesses. Economy and scalability are inevitable because they impact the flourishing of all online businesses. The objective of this study is to distinguish the differences between Amazon Lambda versus EKS and ECS using EC2 instances from the Economy and scalability perspectives. The study aims to give programmers without prior knowledge about the services an overall picture of their billing models, scalability,  and the goal each service is meant to deliver. A literature review was used to identify the related studies done earlier in this area of research. The data captured from the literature studies were enriched with an empirical study, namely, survey research  with semi-structured interviews. Snowballing was used to identify more interviewees with the help of the earlier selected respondents. After conducting the semi-structured online interviews with five participants, the recordings were transcribed. Finally, the Thematic Analysis approach was used to analyze the collected qualitative data from the transcripts. It was concluded that Lambda was useful for infrequent and minor workloads without long processing tasks, with a  free automatic and managed scalability. For websites doing massive processing or getting large requests constantly, EKS or ECS would be a better choice. However, ECS and EKS cost more than Lambda when working with smaller workloads. EKS has multi-direction scalability, making it more flexible than Lambda and ECS. However, this comes with additional costs and complexity, but it is cost-effective for bigger businesses. Ultimately, in real-world cloud architecture, it is relatively common to rely on a combination of cloud services to fulfill the economic or auto scalability objectives of a business instead of a single one.
29

Reservation income and the decision to borrow : an empirical analysis of interlinked informal credit contracts in the Peruvian Amazon

Kjüllerstrüm, Mónica Isabel Bento De Braga January 2002 (has links)
This thesis examines factors that determine household reliance on interlinked informal credit contracts for fish in the Peruvian Amazon, and the degree to which implicit interest rates in these contracts are explained by transaction costs, administrative costs and lender risk. / A probit model was used to determine household likelihood to borrow, using survey data collected in the region. This likelihood is found to depend on access to alternative activities to generate income, household resilience to income volatility, and demographics: age, education and mobility. / High implicit interest rates (112%) are not explained by the average costs (67%) incurred by local lenders. Market access and household demand elasticity seem to be the main factors determining the degree to which forest peasants are exploited. Local lenders are found to receive credit at rates below the cost to non-resident lenders who use the credit relationship to secure a supply of fish.
30

Reservation income and the decision to borrow : an empirical analysis of interlinked informal credit contracts in the Peruvian Amazon

Kjüllerstrüm, Mónica Isabel Bento De Braga January 2002 (has links)
No description available.

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