• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 97
  • 53
  • 8
  • 7
  • 4
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 187
  • 29
  • 29
  • 25
  • 22
  • 22
  • 22
  • 22
  • 21
  • 21
  • 19
  • 18
  • 17
  • 15
  • 14
  • 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.
121

Ska det vara så svårt att ta det lugnt en stund? : - om svårigheten att bemöta barns behov av lugn och ro i den moderna förskolemiljön / Shuld it be so hard to take it easy for a while? : about the difficulty of meeting the children´s need for peace and quit in the modern preschool environment

Fredriksson, Annika January 2013 (has links)
I min essä beskriver jag den öppna miljön, med ett modernt och nytänkande arbetssätt som blir allt vanligare inom förskolan. I den nya moderna förskolan öppnas innemiljöerna upp allt mer för att skapa möjligheter till ett ökat samspel och lärande mellan barnen. Pedagogiken säger att vi pedagoger ska bygga miljöer och inspirera barnen till att själva söka kunskap, men här anser jag att det finns barn som får problem. Många barn har svårt att anpassa sig till den stora barngruppen och utmärker sig för att vara "stökiga" eftersom de inte klarar av att sortera alla sinnesintryck runt omkring sig. Jag ser att barn med koncentrationssvårigheter blir allt vanligare inom förskolan och är orsakat av miljön de befinner sig i. Syftet med min essä är att undersöka hur miljön kan vara grunden till barn som har ett oroligt beteende och hur jag som pedagog kan ge dem möjligheter att lättare komma till ro i en verksamhet som saknar avdelade rum. Genom att jag reflekterar över mitt pedagogiska förhållningssätt kommer jag fram till att alla barn inte kan bemötas lika. För att alla barn ska känna en lugn och trygg lärandemiljö på förskolan krävs det att vi pedagoger har kunskap om hur flexibla rum, vardagsstress och stora barngrupper kan påverka barnets koncentration till eget lärande. / In my essay I describe the open environment, with a modern and innovative way of work that is becoming more and more common in preschools. In the new modern preschool the indoor environments are becoming more open to create an increased interaction and learning between the children. The science of education says that the pedagogue shall create environments and inspire the children to search their own knowledge, but according to me this is a something that causes problems for some children. Many children have difficulties to adapt to the large group of children and are characterized as "messy" since they are unable to sort all the perception they are exposed to. I experience that children with concentration disabilities are becoming more and more common at preschools and that it is caused by the environments they are situated in. The purposes of my essay is to investigate how the environment can be the cause of a restless behavior and how I, as a pedagogue, can give them the opportunity to easier find peace in a preschool which doesn’t have any separate rooms. By reflecting over my pedagogical attitude I find that not all children can be met the same way. For every children to experience a calm and safe learning environment at preschool, it is necessary that we pedagogues have knowledge about how flexible rooms, everyday stress and large groups of children can effect the concentration of learning for the child.
122

Din, don, don: Mestre Paraná e o Grupo Folclórico de Capoeira São Bento Pequeno (1950-1960) / Din, Don,Don: Mestre Paraná and the grupo folclórico de capoeira São BentoPequeno (1950-1960)

Alisson Bernardo Pinheiro 30 January 2011 (has links)
This work seeks to question the construction of memory and history of capoeira in Rio de Janeiro in the second half of the twentieth century. Capoeira as a cultural manifestation is the subject of a growing number of art works, from theatrical to cinema movies, as well as government actions, with emphasis on its register as "intangible heritage of Brazilian culture." It is practiced in over 150 countries, and presents itself as one of the identities of Brazilians abroad. In Rio de Janeiro, capoeira had a great historical value in the memory of the nineteenth century, represented in various documents and letters from the State and from the intellectuals of the time. This history has been researched by authors who already attend their works being consecrated by the growing number of people interested in the topic. In contrast, the recent history of this practice is still a rare subject in the historiography, as well as in the other disciplines of the humanities. Thus, through ethnographic research with the "Grupo Folclorico de Capoeira São Bento Pequeno", capoeira school "Mestre Paraná", we question this gap in academic knowledge, as well as its reflections in the formation of "traditions"of capoeira in Rio de Janeiro. Grupo São Bento Pequeno was active in the 1950s and 1960s, a period of renewed growth of capoeira in Rio de Janeiro. / Este trabalho questiona a construção da memória e da história da capoeira no Rio de Janeiro na segunda metade do século XX. A capoeira como manifestação cultural é tema de um crescente número de trabalhos artísticos, desde peças de teatro, filmes para o cinema, bem como de ações do governo, com destaque para seu tombamento como "patrimônio imaterial da cultura brasileira". É praticada em mais de 150 países, onde se apresenta como mais uma das identidades dos brasileiros no exterior. No Rio de Janeiro, deixou marcas profundas na memória do século XIX, representada em documentos variados do Estado e nas letras dos intelectuais da época. História que tem sido pesquisada por autores que já assistem suas obras sendo consagradas pelo crescente número de interessados no tema. Em contrapartida, a história recente desta prática ainda é assunto raro na historiografia, bem como nas demais disciplinas das ciências humanas. Assim, através da pesquisa etnográfica com o Grupo Folclórico de Capoeira São Bento Pequeno, escola de capoeira de Mestre Paraná, questionamos esta lacuna no conhecimento acadêmico, bem como seu reflexo na formação das "tradições" da capoeira no Rio de Janeiro. O Grupo São Bento Pequeno esteve em atividade nas décadas de 1950 e 1960, período de retomada do crescimento da capoeira no Rio de Janeiro.
123

Din, don, don: Mestre Paraná e o Grupo Folclórico de Capoeira São Bento Pequeno (1950-1960) / Din, Don,Don: Mestre Paraná and the grupo folclórico de capoeira São BentoPequeno (1950-1960)

Alisson Bernardo Pinheiro 30 January 2011 (has links)
This work seeks to question the construction of memory and history of capoeira in Rio de Janeiro in the second half of the twentieth century. Capoeira as a cultural manifestation is the subject of a growing number of art works, from theatrical to cinema movies, as well as government actions, with emphasis on its register as "intangible heritage of Brazilian culture." It is practiced in over 150 countries, and presents itself as one of the identities of Brazilians abroad. In Rio de Janeiro, capoeira had a great historical value in the memory of the nineteenth century, represented in various documents and letters from the State and from the intellectuals of the time. This history has been researched by authors who already attend their works being consecrated by the growing number of people interested in the topic. In contrast, the recent history of this practice is still a rare subject in the historiography, as well as in the other disciplines of the humanities. Thus, through ethnographic research with the "Grupo Folclorico de Capoeira São Bento Pequeno", capoeira school "Mestre Paraná", we question this gap in academic knowledge, as well as its reflections in the formation of "traditions"of capoeira in Rio de Janeiro. Grupo São Bento Pequeno was active in the 1950s and 1960s, a period of renewed growth of capoeira in Rio de Janeiro. / Este trabalho questiona a construção da memória e da história da capoeira no Rio de Janeiro na segunda metade do século XX. A capoeira como manifestação cultural é tema de um crescente número de trabalhos artísticos, desde peças de teatro, filmes para o cinema, bem como de ações do governo, com destaque para seu tombamento como "patrimônio imaterial da cultura brasileira". É praticada em mais de 150 países, onde se apresenta como mais uma das identidades dos brasileiros no exterior. No Rio de Janeiro, deixou marcas profundas na memória do século XIX, representada em documentos variados do Estado e nas letras dos intelectuais da época. História que tem sido pesquisada por autores que já assistem suas obras sendo consagradas pelo crescente número de interessados no tema. Em contrapartida, a história recente desta prática ainda é assunto raro na historiografia, bem como nas demais disciplinas das ciências humanas. Assim, através da pesquisa etnográfica com o Grupo Folclórico de Capoeira São Bento Pequeno, escola de capoeira de Mestre Paraná, questionamos esta lacuna no conhecimento acadêmico, bem como seu reflexo na formação das "tradições" da capoeira no Rio de Janeiro. O Grupo São Bento Pequeno esteve em atividade nas décadas de 1950 e 1960, período de retomada do crescimento da capoeira no Rio de Janeiro.
124

Fracionamento de mercúrio em amostras de tecido muscular de peixes coletados na área de influência do AHE Jirau - Bacia do rio Madeira utilizando estratégias metaloproteômicas / Mercury fractionation in muscle tissue from fishes collected in the area of influence of Jirau Power Plant-Basin Madeira river using metaloprotemics strategies

Moraes, Paula Martin de [UNESP] 21 January 2014 (has links) (PDF)
Made available in DSpace on 2015-06-17T19:34:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-01-21. Added 1 bitstream(s) on 2015-06-18T12:48:47Z : No. of bitstreams: 1 000829802.pdf: 1465255 bytes, checksum: 2d7e1dd40db91bb9503377e7965f6c9d (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação do Instituto de Biociências (FUNDIBIO) / Inserido na realidade de contaminação dos rios amazônicos pelo mercúrio, este trabalho busca, por meio do estudo metaloproteômico, a identificação e a caracterização de proteínas do tecido muscular de três espécies diferentes de peixes do rio Madeira que possam atuar como possíveis biomarcadores da toxicidade deste elemento na região de influência do Aproveitamento Hidrelétrico de Jirau (AHE JIRAU). As estratégias para este estudo foram separadas em três componentes distintos: de seletividade, de sensibilidade e estrutural. Ao longo desta pesquisa, diferentes metodologias foram empregadas nessas etapas para o estudo metaloproteômico: componente de seletividade - 2D PAGE no fracionamento bidimensional das proteínas; componentes de sensibilidade - SR XRF e GFAAS para identificação e quantificação do mercúrio nos spots proteicos, respectivamente; componente estrutural - ESI MS MS na caracterização das proteínas identificadas com mercúrio em sua estrutura. As espécies de peixes estudadas foram: dourada (Brachyplatystoma rousseauxii), pacu (Mylossoma sp., Myleus sp.) e jaraqui (Semaprochilodus sp.). Entre os resultados obtidos, a 2D PAGE se mostrou eficiente no fracionamento proteico do tecido muscular de peixes. Utilizando análises qualitativas por SR XRF foi possível identificar a presença de mercúrio no spot 68 da dourada (massa molar 20,8 kDa e pI 5,6) e no spot 72 do pacu (massa molar 19,8 kDa e pI 7,5). Determinações por GFAAS permitiram a quantificação do mercúrio no tecido muscular e em 28 spots, que apresentaram concentrações de 11,3 a 41,2 mg g-1 de mercúrio em sua composição; esses resultados possibilitaram o cálculo da estimativa do número de átomos de mercúrio por molécula de proteína entre os spots estudados. Após análise por ESI MS MS, foi possível caracterizar oito proteínas com diferentes isoformas em 21 spots que apresentaram pI de 3,5 a 9,8 e massa molar ... / Inserted in the context of mercury contamination of Amazonian rivers, this work pursues through metaloproteomic study the identification and characterization of proteins from muscle tissue of three different species of fish from Madeira River that may act as potential biomarkers of toxicity of this element in the region of influence of Jirau Power Plant. The strategies for this study were separated into three distinct components: selectivity, sensitivity and structural. Throughout this research, different methodologies were used in these steps for metaloproteomic study: component of selectivity - 2D PAGE in two-dimensional proteins fractionation; components of sensitivity - SR XRF and GFAAS for mercury identification and quantification in protein spots, respectively; structural component - ESI MS MS in the characterization of proteins identified with mercury in its structure. The species studied were: dourada (Brachyplatystoma rousseauxii), pacu (Mylossoma sp., Myleus sp.) and jaraqui (Semaprochilodus sp.). Among the results, the 2D PAGE proved efficient in protein fractionation of fish muscle tissue. Using qualitative analysis by SR XRF was possible to identify the presence of mercury in the spot 68 of dourada (molar mass of 20.8 kDa and pI 5.6) and spot 72 of pacu (molar mass of 19.8 kDa and pI 7.5). Determinations by GFAAS allowed the mercury quantification in muscle tissue and in 28 spots that showed concentrations from 11.3 to 41.2 mg g-1 of mercury in its composition; these results enabled an estimative calculation of the number of mercury atoms per protein molecule between the spots studied. After analysis by ESI MS MS it was possible to characterize eight proteins with different isoforms in 21 spots that showed pI 3.5 to 9.8 and molar mass between 9.9 and 18.1 kDa, indicating that these proteins may be potential candidates for mercury biomarkers in ...
125

Fracionamento de mercúrio em amostras de tecido muscular de peixes coletados na área de influência do AHE Jirau - Bacia do rio Madeira utilizando estratégias metaloproteômicas /

Moraes, Paula Martin de. January 2014 (has links)
Orientador: Pedro de Magalhães Padilha / Banca: Clelia Akiko Hiruma Lima / Banca: Marília Afonso Rabelo Buzalaf / Banca: Paulo dos Santos Roldan / Banca: Lincolin Carlos Silva de Oliveira / Resumo: Inserido na realidade de contaminação dos rios amazônicos pelo mercúrio, este trabalho busca, por meio do estudo metaloproteômico, a identificação e a caracterização de proteínas do tecido muscular de três espécies diferentes de peixes do rio Madeira que possam atuar como possíveis biomarcadores da toxicidade deste elemento na região de influência do Aproveitamento Hidrelétrico de Jirau (AHE JIRAU). As estratégias para este estudo foram separadas em três componentes distintos: de seletividade, de sensibilidade e estrutural. Ao longo desta pesquisa, diferentes metodologias foram empregadas nessas etapas para o estudo metaloproteômico: componente de seletividade - 2D PAGE no fracionamento bidimensional das proteínas; componentes de sensibilidade - SR XRF e GFAAS para identificação e quantificação do mercúrio nos spots proteicos, respectivamente; componente estrutural - ESI MS MS na caracterização das proteínas identificadas com mercúrio em sua estrutura. As espécies de peixes estudadas foram: dourada (Brachyplatystoma rousseauxii), pacu (Mylossoma sp., Myleus sp.) e jaraqui (Semaprochilodus sp.). Entre os resultados obtidos, a 2D PAGE se mostrou eficiente no fracionamento proteico do tecido muscular de peixes. Utilizando análises qualitativas por SR XRF foi possível identificar a presença de mercúrio no spot 68 da dourada (massa molar 20,8 kDa e pI 5,6) e no spot 72 do pacu (massa molar 19,8 kDa e pI 7,5). Determinações por GFAAS permitiram a quantificação do mercúrio no tecido muscular e em 28 spots, que apresentaram concentrações de 11,3 a 41,2 mg g-1 de mercúrio em sua composição; esses resultados possibilitaram o cálculo da estimativa do número de átomos de mercúrio por molécula de proteína entre os spots estudados. Após análise por ESI MS MS, foi possível caracterizar oito proteínas com diferentes isoformas em 21 spots que apresentaram pI de 3,5 a 9,8 e massa molar ... / Abstract: Inserted in the context of mercury contamination of Amazonian rivers, this work pursues through metaloproteomic study the identification and characterization of proteins from muscle tissue of three different species of fish from Madeira River that may act as potential biomarkers of toxicity of this element in the region of influence of "Jirau Power Plant". The strategies for this study were separated into three distinct components: selectivity, sensitivity and structural. Throughout this research, different methodologies were used in these steps for metaloproteomic study: component of selectivity - 2D PAGE in two-dimensional proteins fractionation; components of sensitivity - SR XRF and GFAAS for mercury identification and quantification in protein spots, respectively; structural component - ESI MS MS in the characterization of proteins identified with mercury in its structure. The species studied were: "dourada" (Brachyplatystoma rousseauxii), "pacu" (Mylossoma sp., Myleus sp.) and "jaraqui" (Semaprochilodus sp.). Among the results, the 2D PAGE proved efficient in protein fractionation of fish muscle tissue. Using qualitative analysis by SR XRF was possible to identify the presence of mercury in the spot 68 of "dourada" (molar mass of 20.8 kDa and pI 5.6) and spot 72 of "pacu" (molar mass of 19.8 kDa and pI 7.5). Determinations by GFAAS allowed the mercury quantification in muscle tissue and in 28 spots that showed concentrations from 11.3 to 41.2 mg g-1 of mercury in its composition; these results enabled an estimative calculation of the number of mercury atoms per protein molecule between the spots studied. After analysis by ESI MS MS it was possible to characterize eight proteins with different isoforms in 21 spots that showed pI 3.5 to 9.8 and molar mass between 9.9 and 18.1 kDa, indicating that these proteins may be potential candidates for mercury biomarkers in ... / Doutor
126

Estado nutricional relativo ao zinco de crianças de duas comunidades ribeirinhas amazônicas, na cidade de Porto Velho - RO / Nutritional status on the zinc of children from two Amazonian riverines communities, in Porto Velho RO.

Rafael Barofaldi Bueno 09 April 2009 (has links)
Estudos epidemiológicos na Região Amazônica são escassos, principalmente aqueles que fazem diagnósticos do estado nutricional relativo a micronutrientes populações que vivem em comunidades ribeirinhas isoladas. Portanto, este estudo objetivou avaliar o estado nutricional relativo ao zinco de crianças em duas comunidades ribeirinhas da Cidade de Porto Velho RO: Gleba do Rio Preto e Demarcação. Foram avaliadas 39 crianças entre 3 e 9 anos, destas 29 da Demarcação e 10 da Gleba do Rio Preto. O perfil sócio-econômico mostrou que todas as famílias avaliadas não tinham destino adequado para os dejetos, as únicas fontes de água eram os rios ou poços cacimba e a principal fonte de renda era a cultura de subsistência, fornecendo renda mensal inferior a um salário mínimo. A avaliação do consumo alimentar mostrou que 39% das crianças avaliadas tinham ingestão de zinco inferior a EAR, a adequação calorica mostrou que 50% das crianças avaliadas tinham ingestão calórica inferior a 90%, no entanto, 92% das crianças tinham ingestão adequada de proteínas. A avaliação antropométrica, de acordo com o escore Z, mostrou que 92%, 84% e 86% das crianças estavam eutróficas para os padrões Estatura/Idade, Peso/Estatura e Peso/Idade, respectivamente. Na avaliação da concentração de zinco no plasma foi observada uma prevalência de deficiência em 90% dos casos e a concentração do zinco eritrocitário mostrou 71% de deficiência. Assim, pode-se concluir que o estado nutricional relativo ao zinco é grave, visto que a ingestão e as concentrações deste nutriente nos parâmetros avaliados estão reduzidas na maioria da população avaliada. / Epidemiological studies in Amazon Region are rarely, especially those that evaluated micronutrients nutritional status on isolated communities. This study aimed to evaluate zinc nutritional status from children who lives in two riverine communities from Porto Velho City RO; Gleba Rio Preto and Demarcação. We carried out of 39 children (3 to 9 years old). The economical and social profile showed that all families had no appropriate dejections destination, the waters sources were from well and rivers and the main source income were from subsistence culture. The food assessment showed 39% from evaluated children had no adequate zinc intake according EAR, the calorie intake was inadequate on 50% from evaluated children. The anthropometrics evaluation showed, according Z score, 92%, 84 e 86% of children were eutrophics to the standards Height/Age, Weight/Height and Weight/Age, respectively. The assessment of zinc concentrations on serum showed a prevalence of deficiency in 90% of the evaluated cases, and the zinc concentration on erythrocytes showed 71% of deficiency and 21% of normality in the evaluated children. Thus, we can conclude the nutritional status is severe, therefore the zinc intake and zinc concentrations are reduced in majority assessed population.
127

Design and economic evaluation of solar-powered hybrid multi effect and reverse osmosis system for seawater desalination

Filippini, G., Al-Obaidi, Mudhar A.A.R., Manenti, F., Mujtaba, Iqbal M. 16 May 2019 (has links)
Yes / Reducing the cost of fresh water has always been a major concern in the desalination industry. A solar powered hybrid multi-effect distillation and reverse osmosis desalination plant (MED+RO) has been designed and optimised from an economical point of view in a previous work by the same authors. In the present study, the possibility of coupling the desalination plant with a photovoltaic (PV) solar farm is investigated, with the aim of generating electricity at low cost and in a sustainable way. A detailed mathematical model for the PV system has been implemented from the literature. Interestingly, the model can predict the cost of the PV system in terms of capital cost and electricity cost per kWh considering the input data of solar irradiation, duration of daylight and technical specification of a real solar module. Consequently, the solar PV model has been combined with the desalination model, which enables to estimate the cost of fresh water per cubic meter. Data about four locations, namely Isola di Pantelleria (IT), Las Palmas (ES), Abu Dhabi (UAE), and Perth (AUS), have been used to economically test the feasibility of installing the proposed plant, and especially of the PV solar farm.
128

Optimal scheduling, design, operation and control of reverse osmosis desalination. Prediction of RO membrane performance under different design and operating conditions, synthesis of RO networks using MINLP optimization framework involving fouling, boron removal, variable seawater temperature and variable fresh water demand.

Sassi, Kamal M. January 2012 (has links)
An accurate model for RO process has significant importance in the simulation and optimization proposes. A steady state model of RO process is developed based on solution diffusion theory to describe the permeation through membrane and thin film approach is used to describe the concentration polarization. The model is validated against the operation data reported in the literature. For the sake of clear understanding of the interaction of feed temperature and salinity on the design and operation of RO based desalination systems, simultaneous optimization of design and operation of RO network is investigated based on two-stage RO superstructure via MINLP approach. Different cases with several feed concentrations and seasonal variation of seawater temperature are presented. Also, the possibility of flexible scheduling in terms of the number of membrane modules required in operation in high and low temperature seasons is investigated A simultaneous modelling and optimization method for RO system including boron removal is then presented. A superstructure of the RO network is developed based on double pass RO network (two-stage seawater pass and one-stage brackish water pass). The MINLP problem based on the superstructure is used to find out an optimal RO network which will minimize the total annualized cost while fulfilling a given boron content limit. The effect of pH on boron rejection is investigated at deferent seawater temperatures. The optimal operation policy of RO system is then studied in this work considering variations in freshwater demand and with changing seawater temperature throughout the day. A storage tank is added to the RO layout to provide additional operational flexibility and to ensure the availability of freshwater at all times. Two optimization problems are solved incorporating two seawater temperature profiles, representing summer and winter seasons. The possibility of flexible scheduling of cleaning and maintenance of membrane modules is investigated. Then, the optimal design and operation of RO process is studied in the presence of membrane fouling and including several operational variations such as variable seawater temperature. The cleaning schedule of single stage RO process is formulated as MINLP problem using spiral wound modules. NNs based correlation has been developed based on the actual fouling data which can be used for estimating the permeability decline factors. The correlation based on actual data to predict the annual seawater temperature profile is also incorporated in the model. The proposed optimization procedure identified simultaneously the optimal maintenance schedule of RO network including its design parameters and operating policy. The steady state model of RO process is used to study the sensitivity of different operating and design parameters on the plant performance. A non-linear optimization problem is formulated to minimize specific energy consumption at fixed product flow rate and quality while optimizing the design and operating parameters. Then the MINLP formulation is used to find the optimal designs of RO layout for brackish water desalination. A variable fouling profile along the membrane stages is introduced to see how the network design and operation of the RO system are to be adjusted Finally, a preliminary control strategy for RO process is developed based on PID control algorithm and a first order transfer function (presented in the Appendix). / Government grant
129

Možnosti ovlivnění vývoje motoriky laboratorního potkana opakovaným podáváním specifického antagonisty NMDA receptoru / Possible influencing the motor performance of developing rats by repeated administration of the NMDA receptor antagonist specific for NR2 subunit

Kozlová, Lucie January 2016 (has links)
Nonspecific NMDA receptor antagonists induce hyperlocomotion in rats. The aim of this work is to determine whether the NMDA receptor antagonist specific for NR2 subunit exhibit similar negative effect as nonspecific antagonists. This subunit is predominant in the brain in the early postnatal period. The introduction summarizes the data on NMDA receptors and the development of rat. The experimental part deals with the action of a specific NMDA receptor antagonist Ro 25-6981 on motor performance of developing rats. Substance was repeatedly administered to rats at postnatal days 7 to 11. Spontaneous locomotion and motor performance of the animals were repeatedly tested up to adulthood by battery of tests appropriate for individual ages. Our research demonstrated that this substance does not have significant effect on motor system of laboratory rat and that it might be further tested as a possible age-bound antiepileptic drug.
130

Estimativa de emissão de carbono por difusão CO2 e CH4 na bacia do Ji-Paraná /

Gomes, Beatriz Machado. January 2009 (has links)
Orientador: Chang Hung Kiang / Banca: Amauri Antonio Menegário / Banca: Alex Vladmir Krusche / Banca: Ene Glória da Silveira / Banca: Roberto Naves Domingos / Resumo: O objeto de estudo é a estimativa de fluxo de CO2 e CH4 em ambiente aquático, quantificado por medidas diretas com câmara flutuante para o dióxido de carbono e da pressão parcial do CO2 e CH4 (PCO2 e PCH4). A área de estudo localiza-se na Bacia do Ji-Paraná, integrante da Região Hidrográfica do rio Madeira - RO. A amostragem foi mensal, de maio 2006 a fevereiro 2008. Através da amostragem com câmara flutuante foi possível calcular o coeficiente de troca gasosa (K), expresso como K600, para todos os rios amostrados, cuja média geral foi de 23,5 ± 8,5 cm h−1 para o CO2 e 28,8 ± 10,4 cm h−1 para CH4. Os valores estimados para fluxo de CO2 com a câmara foram de 1.845,1 mg C m−2 d−1, por equilíbrio trocas gasosas de 1.690,1 mg C m−2 d−1; e de 24,3 mg C m−2 d−1 para CH4. O período seco apresentou menor fluxo de CO2 em relação à cheia. Para CH4 o fluxo apresentou variabilidade temporal. Os resultados evidenciam que a emissão de gases pelo sistema aquático é um importante integrante do ciclo do carbono e que o fluxo de CO2 esta relacionado ao comportamento hidrológico sazonal característico para a Amazônia. / Abstract: The object of study is the estimated flow of CO2 and CH4 in the aquatic environment, quantified by direct measurements with floating chamber for carbon dioxide and partial pressure of CO2 and CH4 (PCO2 and PCH4). The study area is located in Ji-Parana River Basin, river basin of the river Madeira - RO. Sampling was monthly, from May 2006 to February 2008. By sampling with floating chamber was possible to calculate the gas exchange coefficient (K), expressed as K600, for all the rivers sampled, whose overall average was 23,5 ± 8,.5 cm h-1 for CO2 and 28, 8 ± 10.4 cm h-1 for CH4 The estimated values for flow of CO2 with the chamber were 1.845,1 mg C m-2 d-1, for gas exchange balance of 1.690,1 mg C m-2 d-1, and 24,3 mg C m -2 d-1 for CH4. The falling water had lower flow of CO2 in relation to the rising water. CH4 flow presented to the temporal variability. The results show that the emission of gases by the water system is an important part of the carbon cycle and the flow of CO2 is related to seasonal hydrological behavior characteristic for the Amazon. / Doutor

Page generated in 0.0417 seconds