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Simulating the flow of some non-Newtonian fluids with neural-like networks and stochastic processesTran-Canh, Dung January 2004 (has links)
The thesis reports a contribution to the development of neural-like network- based element-free methods for the numerical simulation of some non-Newtonian fluid flow problems. The numerical approximation of functions and solution of the governing partial differential equations are mainly based on radial basis function networks. The resultant micro-macroscopic approaches do not require any element-based discretisation and only rely on a set of unstructured collocation points and hence are truly meshless or element-free. The development of the present methods begins with the use of the multi-layer perceptron networks (MLPNs) and radial basis function networks (RBFNs) to effectively eliminate the volume integrals in the integral formulation of fluid flow problems. An adaptive velocity gradient domain decomposition (AVGDD) scheme is incorporated into the computational algorithm. As a result, an improved feed forward neural network boundary-element-only method (FFNN- BEM) is created and verified. The present FFNN-BEM successfully simulates the flow of several Generalised Newtonian Fluids (GNFs), including the Carreau, Power-law and Cross models. To the best of the author's knowledge, the present FFNN-BEM is the first to achieve convergence for difficult flow situations when the power-law indices are very small (as small as 0.2). Although some elements are still used to discretise the governing equations, but only on the boundary of the analysis domain, the experience gained in the development of element-free approximation in the domain provides valuable skills for the progress towards an element-free approach. A least squares collocation RBFN-based mesh-free method is then developed for solving the governing PDEs. This method is coupled with the stochastic simulation technique (SST), forming the mesoscopic approach for analyzing viscoelastic flid flows. The velocity field is computed from the RBFN-based mesh-free method (macroscopic component) and the stress is determined by the SST (microscopic component). Thus the SST removes a limitation in traditional macroscopic approaches since closed form constitutive equations are not necessary in the SST. In this mesh-free method, each of the unknowns in the conservation equations is represented by a linear combination of weighted radial basis functions and hence the unknowns are converted from physical variables (e.g. velocity, stresses, etc) into network weights through the application of the general linear least squares principle and point collocation procedure. Depending on the type of RBFs used, a number of parameters will influence the performance of the method. These parameters include the centres in the case of thin plate spline RBFNs (TPS-RBFNs), and the centres and the widths in the case of multi-quadric RBFNs (MQ-RBFNs). A further improvement of the approach is achieved when the Eulerian SST is formulated via Brownian configuration fields (BCF) in place of the Lagrangian SST. The SST is made more efficient with the inclusion of the control variate variance reduction scheme, which allows for a reduction of the number of dumbbells used to model the fluid. A highly parallelised algorithm, at both macro and micro levels, incorporating a domain decomposition technique, is implemented to handle larger problems. The approach is verified and used to simulate the flow of several model dilute polymeric fluids (the Hookean, FENE and FENE-P models) in simple as well as non-trivial geometries, including shear flows (transient Couette, Poiseuille flows)), elongational flows (4:1 and 10:1 abrupt contraction flows) and lid-driven cavity flows.
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Regional Disaster Events and Environment Simulations by Atmosphere-Ocean Coupled Model / 大気・海洋結合モデルによる地域環境・災害事象シミュレーション / タイキ カイヨウ ケツゴウ モデル ニ ヨル チイキ カンキョウ サイガイ ジショウ シミュレーションLEE, Han Soo 25 September 2007 (has links)
学位授与大学:京都大学 ; 取得学位: 博士(工学) ; 学位授与年月日: 2007-09-25 ; 学位の種類: 新制・課程博士 ; 学位記番号: 工博第2844号 ; 請求記号: 新制/工/1418 ; 整理番号: 25529 / An atmosphere-ocean coupled model was developed based on a preexisting non-hydrostatic mesoscale atmosphere model (MM5) and non-hydrostatic ocean circulation model (MITgcm). This model together with a pre-established wind-wave-currents coupled model was applied to a number of regional environmental issue and disaster events to reproduce the present status and past situations and to help our understanding of the physical processes of such problems in terms of atmosphere-ocean interactions including the sea surface waves in the interface between air and sea. The disaster events and environmental issue studied in this thesis are follows. 1) Storm surge induced by Hurricane Katrina in the Gulf coast of USA in 2005. 2) Extreme high waves at Hara coast, Suruga Bay in Japan caused by the super-Typhoon TIP in 1979. 3) Positive and negative feedbacks in typhoon-ocean interaction in case of Typhoon ETAU in 2003. 4) Thermal water circulation in a dam-made lake (Yachiyo Lake) in Hiroshima, Japan concerning on the hydrodynamics in the lake. 5) Reanalysis of the past 47 storms that caused disasters in West Kyushu, Japan. 6) Wave overtopping simulation over through the submerged offshore breakwater and enhance seawall. The Regional Environment and Disaster Prevention Simulator is proposed and constructed based on the regional atmosphere-ocean coupled model in this thesis of which the objective was improvement of the numerical assessment method to disaster events and environment problems by introducing he coupling effects between different systems. / Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第13373号 / 工博第2844号 / 新制||工||1418(附属図書館) / 25529 / UT51-2007-Q774 / 京都大学大学院工学研究科社会基盤工学専攻 / (主査)教授 関口 秀雄, 教授 間瀬 肇, 教授 中北 英一 / 学位規則第4条第1項該当
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Variabilidade decadal da zona de convergência intertropical e sua influência na pluviosidade da região norte do Brasil / Intertropical convergence zone decadal variability and its impact on the Northern Brazilian rainfallAndrade, Lene da Silva 09 March 2007 (has links)
The present work focused on the possible influence of the Pacific Decadal
Oscillation (PDO) on the positioning and intensity of the Intertropical Convergence
Zone (ITCZ) during its annual cycle over the Atlantic Ocean and its impact in the
rainfall totals in the northern South American continent. For this purpose, the mean
annual fields of outgoing longwave radiation (OLR), sea surface temperature (SST),
omega (ω), meridional wind (V) and precipitation rate (P) of Reanalysis data sets
(NCEP/NCAR) were analysed. In addition, observed rainfall monthly mean series
(INMET and HIDROWEB), the University of Delawere (UDEL) rainfall, interpolated
in a 0.5°x0.5° grid, and the PDO indices found in the NOAA/ESRL/PSD site were used
to support the analyses. The results were visualized with applets available in the
ESRL/PSD/NOAA s site as well as GrADS software. The records period 1948-2005
was divided into PDO cold phase (1948-1976), warm phase (1977- 1998) and current
phase (1999-2005), which was used to verify the climate tendency of the last seven
years. The results suggested that the ITCZ remained farther north of its mean position
during the PDO cold phase. Apparently, the ascending branch of the Hadley Cell was
displaced farther north and the descendent branch of the Walker Circulation positioned
farther west of their normal positions. This pattern led to a rainfall reduction in parts of
Amazonia. In the PDO cold phase, the normalized rainfall indices showed a more
noticeable rainfall reduction (increase) western (eastern) of 52°W, in the State of Pará.
In the PDO warm phase, opposite circulation patterns and higher climate variability
were observed. The results suggested that the PDO, in general, modified the SST
patterns in the Atlantic and, as a consequence, the positioning and intensity of the ITCZ.
There are evidences that the PDO is experiencing a new cold phase. Thus, one expects
that the ITCZ and the Amazonian rainfall present a similar behaviour of previous cold
phase. Particular attention should be paid to the Brazilian States of Roraima and
Maranhão, eastern Pará State and western Amazonas State, including Colombia,
Venezuela e north-eastern Bolivia, that may experience a sensible rainfall reduction
during the next 10 years. Another relevant result was relative to a possible enhancement
of convection and rainfall over the southern Saharan region (Sahel), Africa, during the
present PDO phase. It was noticed that it rained more in the region till 1975, when the
SST anomalies of Equatorial Guinea Gulf were negative and the wind south component
was stronger. These conditions seem to be returning. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / No presente trabalho dissertou-se sobre as possíveis influências da Oscilação Decadal
do Pacífico (ODP) no posicionamento e intensidade da Zona de Convergência
Intertropical (ZCIT) em seu ciclo anual sobre o Oceano Atlântico e seus impactos na
precipitação do norte da América do Sul. Para tanto, foram utilizados os campos médios
de radiação de ondas longas emergentes (ROLE), temperatura da superfície do mar
(TSM), omega, vento meridional e precipitação, elaborados a partir do conjunto de
dados de Reanalises do NCEP/NCAR, além de índices de ODP do ESRL/PSD/NOAA e
séries temporais da precipitação média observada de postos pluviométricos (INMET
and HIDROWEB) e a interpolada pela University of Delawere (UDEL) numa grade de
0,5°x0,5°. Os aplicativos disponíveis no site do ESRL/PSD/NOAA, bem como o
GrADS, foram utilizados para visualizar os resultados das análises. O período de 1948 a
2005, correspondendo às fases fria (1948- 1976), quente (1977- 1998) e atual (1999-
2005) da ODP, foi tomado como base, este último tendo sido utilizado para verificar
tendências climáticas contemporâneas. Os resultados indicaram que, durante a fase fria
da ODP, a ZCIT esteve mais ao norte de sua posição climatológica. O ramo ascendente
da célula de Hadley permaneceu mais deslocado para norte e o descendente da
circulação de Walker mais deslocado para oeste. Essa configuração foi responsável pelo
decréscimo da precipitação observado em parte da Amazônia. Os índices de
precipitação padronizada (IPP) mostraram redução (aumento) mais acentuada da chuva
a oeste (leste) de 52°W, no Estado do Pará. Durante a fase quente da ODP, foram
observadas configurações opostas e maior variabilidade climática interanual. De
maneira geral, as análises mostraram que a ODP mudou a configuração das TSM no
Atlântico e influenciou o posicionamento e intensidade da ZCIT. Sugeriram, também,
que a ODP parece estar experimentando sua nova fase fria. Com base nesses resultados,
espera-se que a ZCIT e a precipitação, apresentem variabilidade semelhante à fase fria
anterior. Dessa forma, particular atenção, deve ser atribuída a regiões dos Estados de
Roraima, Oeste do Amazonas, leste do Pará e Maranhão, além da Colômbia, Venezuela
e nordeste da Bolívia, que deverão sofrer redução em sua precipitação média nos
próximos 10 a 15 anos. Outro resultado relevante diz respeito aumento da convecção e
precipitação que poderá ocorrer no Sul do Deserto de Sahara (Sahel), África, ao longo
da atual fase da ODP. Nessa região, foi notado que choveu mais até 1975, quando o
Golfo da Guiné apresentou anomalias negativas de TSM e a componente sul do vento
esteve mais forte.Aparentemente, essas condições estão retornando.
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Características da precipitação pluviométrica do nordeste brasileiro e seus padrões de acoplamento com as TSM do Pacífico Equatorial e Atlântico Sul. / Rainfall characteristics in northeastern brazil and their patterns coupling with sst equatorial Pacific and South Atlantic.Coelho, Sergio Carlos Buarque 08 February 2010 (has links)
The need to establish the long-term precipitation led many authors to try to understand why
regulators of interannual climate variability over the Northeast of Brazil. Fluctuations in the
equatorial Pacific SST acts as a modulator of climate on various time scales and are
associated with the phenomenon (El Niño / Southern Oscillation). We analyzed the patterns of
monthly and quarterly precipitation in Northeast Brazil (with emphasis on the eastern part of
Northeast Brazil), related to the anomalies of surface temperatures of the equatorial Pacific
and south Atlantic, from the SST data obtained from the Comprehensive Ocean-Atmosphere
Data System and precipitation data from the universe as we know from Delaware from 1950
to 1999. The monthly precipitation by the phases of the Pacific Decadal Oscillation and
rainfall were arranged both quarterly and lag. Were defined conditions of El Niño: positive
anomaly; positive derivative; positive derivative if and only if the anomalies were positive
and the anomaly index Interoceanic (AI). The best parameter for prediction of quarterly
rainfall within the rainy season in NE, was the condition of positive derivative of the SST of
the Pacific, one month before the rain (lag1) with positive correlation of 0.3 to 95% of
significance, falling to 0.2 (lag2), from February to May versus April-July rainfall. The study
confirmed the low levels of correlation, have been mentioned by other authors about the ENE
and the SST anomalies in the equatorial Pacific. The monthly mean SST anomalies in the
South Atlantic and equatorial Pacific combined showed best results when correlated with
monthly precipitation over northern northeast Brazil. On the east of NE was positive
correlation of 0.5, on the north of NE was 0.6, decreasing to 0.3 correlation over southern
northeast at 95% significance. The two signals combined accounted for (r = 0.7) 49% of the
variability in signal Comparable with isolated Pacific, which was correlated with seasonal
rainfall. The increase in estimates of rainfall over east of NE occurred from the inclusion of
the Atlantic SST anomalies and considered during the calculation of the average normal
changes of signal detected in the Pacific Decadal Oscillation. / Fundação de Amparo a Pesquisa do Estado de Alagoas / A necessidade em prever a precipitação a longo prazo levaram muitos autores a tentar
compreender os motivos reguladores da variabilidade interanual climática sobre o Nordeste
do Brasil. As flutuações nas TSM do Pacífico equatorial atuam como um modulador climático
em várias escalas de tempo e estão associados ao fenômeno (El Niño / Oscilação Sul).
Analisamos os padrões mensais e quadrimestrais da precipitação do Nordeste do Brasil (com
ênfase sobre a parte leste do Nordeste do Brasil), relacionadas às anomalias das temperaturas
da superfície dos oceanos Pacífico equatorial e Atlântico sul, a partir dos dados de TSM
obtidos do Compreensiv Ocean-Atmosphere Data System e dos dados de precipitação da
Universidade de Delaware entre 1950 a 1999. As precipitações mensais pelas fases da
Oscilação Decadal do Pacífico e as precipitações quadrimestral foram dispostas
simultaneamente e em lag. Foram definidas condições de El-Niño: anomalia positiva;
derivada positiva; derivada positiva se e somente se as anomalias fossem positivas e o índice
anomalia Interoceânica (AI). O melhor parâmetro de prognóstico da precipitação
quadrimestral, dentro da estação chuvosa do ENE, foi a condição de derivada positiva das
TSM do Pacifico, um mês antes da chuva (lag1), com de correlação positiva de 0,3 a 95% de
significância, caindo para 0,2 (lag2), de fevereiro-maio versus as chuvas abril-julho.
Confirmaram-se os baixos índices de correlação, já foram mencionados por outros autores a
respeito do ENE e as anomalias da TSM do Pacífico equatorial. As anomalias da TSM médias
mensais do Atlântico sul e Pacífico equatorial combinadas mostraram melhores resultados
quando correlacionadas com a precipitação mensal sobre o NEB. Sobre o ENE correlação
positiva de 0,5; no NNE foi de 0,6; caindo para 0,3 de correlação no SNE a 95% de
significância. Os dois sinais combinados responderam por (r=0,7) 49% da variabilidade
comparado ao sinal isolado do Pacífico, correlacionado com a precipitação quadrimestral. O
aumento na previsão das precipitações sobre o ENE se deu a partir da inclusão das anomalias
da TSM do Atlântico e por considerar durante o cálculo das médias normais as mudanças de
sinal verificadas na Oscilação Decadal do Pacífico.
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The impact of tropical sea surface temperature perturbations on atmospheric circulation over north Canada and GreenlandMcCrystall, Michelle Roisin January 2018 (has links)
Identifying the drivers of Arctic climate variability is essential for understanding the recent rapid changes in local climate and determining the mechanisms that cause them. Remote tropical sea surface temperatures (SST) have been identified in previous studies as having contributed to the recent positive trends in surface temperature and geopotential height at 200 hPa over north Canada and Greenland (1979-2012) through poleward propagating Rossby waves. However, the source and direction of wave propagation on to north Canada and Greenland (NCG) differs across climate datasets indicating that there are still uncertainties surrounding the mechanisms for how the tropics influence the NCG climate. This thesis aims to further investigate the robustness of the trends over NCG and understand how circulation in this region responds to imposed tropical SST perturbations. The eddy 200 hPa geopotential height (Z200) trends over NCG are assessed in a number of different datasets and compared to the response of eddy Z200 over NCG to imposed tropical SST perturbations in a number of sensitivity studies using the HadGEM3 atmosphere-only model. These model experiments are forced with observed differences in SSTs from the beginning and end of the satellite record (1979-1988 and 2003-2012), with spatial perturbations for [i] the entire tropics, [ii] global SSTs, [iii] the tropical Pacific only, [iv] the tropical Atlantic SST only, [v] the tropical Indian Ocean only. The positive spatial trends of eddy Z200 over NCG from ERA-Interim reanalysis is largely captured in ensemble means of two available climate datasets, UPSCALE and AMIP, indicating that this is a robust climate pattern, however, these trends appear to be stronger in the latter part of the record specifically over the UPSCALE period (1985 to 2011). The model sensitivity studies show that a negative eddy Z200 anomaly over NCG was found in response to all imposed tropical SST perturbations (2003-2012) relative to a background state (1979-1988). This was due a stationary trough over the region that was able to intensify in response to a lack of a strong anomalous wave forcing from changes in mid-tropospheric temperature and zonal winds. The forcing from the tropical Atlantic, relative to the other tropical ocean basins, resulted in the largest eddy Z200 response over NCG, indicating its dominance in forcing the large scale tropical signal. The influence of extratropical SST perturbations relative to tropical SST perturbations were also investigated and it was demonstrated that this negative anomaly is largely driven by the change in tropical sea surface temperatures.
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O tratamento diretamente observado \"dots\" e a adesão ao tratamento da tuberculose: significados para os trabalhadores de unidades de saúde da região central do município de São Paulo-São Paulo-Brasil / The treatment directly observed ,SST,(Strictly Supervised Treatment\") and the adhesion to the treatment of tuberculosis:Meanings to health workers of units at the central region of the municipality of Sao Paulo, São Pablo City - BrazilAlba Idaly Muñoz Sanchez 30 November 2007 (has links)
A tuberculose ainda prevalece no cenário epidemiológico mundial e nacional e sua permanência relaciona-se a vários processos, dentre os quais, as desigualdades sociais. A adesão ao tratamento é um aspecto chave para o controle da doença, já que contribui para a diminuição da multirresistência aos fármacos e para o decréscimo da mortalidade. Em função desse panorama que evidencia ainda, a ineficácia dos programas de controle, a Organização Mundial da Saúde-OMS propôs um novo marco para controle da enfermidade, introduzindo a Estratégia do Tratamento Diretamente Observado-DOTS ou Tratamento Supervisionado (TS). Dada a carência de estudos qualitativos sobre o tema no Município de São Paulo, este estudo teve como objetivos: identificar os significados que trabalhadores da saúde manifestam em relação à tuberculose, à adesão ao tratamento e ao Tratamento Diretamente Supervisionado; identificar as potencialidades e os limites da estratégia DOTS numa região do Município de São Paulo; além de apontar alternativas que contribuam no aprimoramento do Programa de Controle da Tuberculose. Após aprovação do projeto por Comitê de Ética em Pesquisa, foram entrevistados 15 trabalhadores da saúde da Subprefeitura da Sé da Secretaria de Saúde do Município de São Paulo, de agosto a dezembro de 2004, por meio de roteiro semi-estruturado. O estudo foi conduzido sob o referencial da Hermenêutica-dialética, tendo sido aplicada técnica apropriada de análise de discurso. Os achados revelam persistência de preconceito, com impacto sobre a assistência e à adesão. Observou-se que esta ultima é influenciada por processos relacionados ao doente (que se referem à sua inserção social), aos serviços de saúde (principalmente quanto à acessibilidade e comunicação com os usuários). A DOTS é apreendida como estratégia que contribui na adesão ao tratamento, ainda que apresente algumas limitações, como a falta de flexibilidade em sua operacionalização em algumas unidades de saúde, assim como a irregularidade dos incentivos. Entretanto, aponta-se sua importante potencialidade, que se revela na perspectiva da formação de vínculo entre o doente e o trabalhador de saúde. Assim, propõe-se o DOTS como interface de encontro e conversa entre trabalhadores e usuários, no âmbito institucional e territorial, o que possibilita a identificação de necessidades de saúde, assim como o encaminhamento de intervenções apropriadas / Tuberculosis still remains in the national and world-wide epidemiological scene and its permanence becomes related to some processes, amongst others, the social inequities. The adhesion to the treatment is a key aspect for the control of the disease given the fact that it contributes to the reduction of the multi-resistance to the pharmacotherapy and to decrease the mortality. In function of this panorama that still evidences, the inefficacy of the control programs, the World Health Organization (WHO) proposes a new frame in order to control the disease, introducing the Strategy Observed Treatment (DOTS) or Strictly Supervised Treatment (SST). Given the lack of qualitative studies about this issue in the municipality of Sao Paulo, this study has as objectives: to identify the meaning that health workers express in relation to tuberculosis the adhesion to treatment, and Strictly Supervised Treatment; to identify the potential and limitations of the strategy in a region of the municipality of Sao Paulo; at the same time to point alternatives that contribute to the improvement of the Program of Control of Tuberculosis. After approval of the project by the Committee of Ethics in Research, 15 health workers of the Secretary of Health of the City of São Paulo were interviewed, from August to December 2004, by means of a half-structuralized survey. The study was lead under the referential of the hermeneutics dialectic applying an appropriate technique of speech analysis. The findings disclose the persistence of preconception, which shows an impact on the assistance and to the adhesion to the treatment. It was noticed that these findings are influenced by related processes to the ill person (which refers to their social insertion), and to the health services (mainly related to the accessibility and the communication with the users). The SST is understood as an strategy that contributes to the adhesion to the treatment, but still presents some limitations, as for example as the lack of flexibility in its operationalization in some health units, as well as the irregularity of the incentives. Meanwhile its important potential is pointed which reveals itself in the perspective. However, its important potentiality is pointed, that if disclosed in the perspective of the conformation of a bond between the ill person and the health worker. Thus, the SST is considered as an interface of meeting and colloquy between health workers and ill people at the institutional and territorial scope, which makes possible the identification of health necessities, as well as the guiding of appropriate interventions
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Caracterização parcial das enzimas envolvidas no metabolismo de frutanos em raízes tuberosas de ichthyothere terminalis (spreng.) Blake / Partial characterization of the enzymes involved in fructan metabolism in tuberous roots of ichthyothere terminalis (spreng.) BlakeSilvestre, Juliana Macêdo 29 May 2015 (has links)
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Dissertação - Juliana Macêdo Silvestre - 2015.pdf: 815128 bytes, checksum: 3bea2ad6d4ab6f0e783b901523c0d838 (MD5)
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Previous issue date: 2015-05-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The Cerrado is a biome that occupies about 25% of Brazilian territory. The seasonality, hot-humid and cold-dry periods, is one of the most striking features of the Cerrado. Reduced rainfall reduces the availability of water in the surface layers of the soil and increases the evaporative demand of air leading to the formation of litter cooperating in cycling soil nutrients. Another important factor in the Cerrado is the occurrence of fires that influence the dispersion, bloom, sprouting and diversity of certain species of plants. The relationship between seasonality, low fertility of soils and naturally occurring fires has shaped vegetative and reproductive strategies of plants from the Cerrado biome. Ichthyothere terminalis (Spreng.) Blake Asteraceae species occurring in the Cerrado, accumulates large amounts of fructans in the underground organs as reserve carbohydrates. Fructans are fructose polymers which are synthesized by the enzymes 1-SST (sucrose: sucrose fructosyltransferase) and FFT (fructan: fructan fructosyltransferase) and depolymerized by 1-FEH (exohidrolase fructan) and invertase. This study investigated the effect of freezing in the production of the enzymes 1-SST, 1-FEH and Invertase in I. terminalis. The partial characterization of these enzymes was performed. The samples were frozen immediately after collection (EB2) or after 6 hours of transport to the laboratory (EB1). The highest amount of protein was found in EB1 (97.81 μg.mL-1) as compared to EB2 (11,90 μg.mL-1). The results showed that the extraction method was efficient, since there was a significant reduction in reducing sugars and the activity of enzymes 1-SST, 1-FEH and Invertase were detected, mainly in the EB1. Enzymes 1-SST and Invertase showed a pH optimum between pH 6 and 7, while the 1-FEH enzyme had a greater spectrum ranging from pH 5 to 7. The three enzymes had an optimum temperature in the range 40 to 50 (°C). This work represents an important step towards understanding the role of these enzymes in the fructan metabolism in I. terminalis. / O Cerrado é um bioma que ocupa cerca de 25% do território brasileiro. A sazonalidade climática, períodos quente-úmido e frio-seco, é uma das características mais marcantes do Cerrado. A redução pluviométrica diminui a disponibilidade de água nas camadas superficiais do solo e eleva a demanda evaporativa do ar levando a formação de serrapilheira que coopera na ciclagem de nutrientes do solo. Outro fator importante no Cerrado é a ocorrência de queimadas que influenciam na dispersão, floração, rebrota e diversidade de certas espécies de plantas. A relação entre sazonalidade climática, baixa fertilidade dos solos e ocorrência natural de queimadas tem moldado estratégias vegetativas e reprodutivas das plantas do bioma Cerrado. Ichthyothere terminalis(Spreng.) Blake, espécie da família Asteraceae ocorrente no Cerrado, acumula grandes quantidades de frutanos em seus órgãos subterrâneos como carboidratos de reserva. Os frutanos são polímeros de frutose sintetizados pelas enzimas 1-SST (sacarose: sacarose frutosiltransferase) e FFT (frutano:frutano frutosiltransferase) e despolimerizados pela 1-FEH (frutano exohidrolase) e invertase. O presente trabalho objetivou estudar o efeito do tempo de congelamento na produção das enzimas 1-SST, 1-FEH e Invertase em I. terminalis. Além disso, a caracterização parcial destas enzimas foi realizada. As amostras coletadas foram congeladas imediatamente após a coleta (EB2) ou após 6 horas de transporte até o laboratório (EB1). A análise da quantidade de proteína extraída mostrou que EB1 apresentou maior quantidade de proteínas (97,81 μg.mL-1) quando comparada com EB2 (11,90 μg.mL-1). O método de extração foi eficiente, pois houve uma redução significativa em açúcares redutores e a atividade das enzimas 1-SST, 1-FEH e Invertase foram detectadas, principalmente no EB1. As enzimas 1-SST e Invertase apresentaram um pH ótimo entre pH 6 e 7, ao passo que a enzima 1-FEH teve um espectro maior variando de pH 5 a 7. As três enzimas apresentaram uma temperatura ótima na faixa de 40 a 50 (°C). Este trabalho representa um passo importante para o entendimento do papel destas enzimas no metabolismo de frutanos em I. terminalis.
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Variabilidade da vazão de regiões homogêneas da bacia hidrográfica amazônica brasileira: teleconexões com a temperatura da superfície do mar (TSM) de 1976 - 2010 / Streamflow variability of homogeneous subregions in the Brazilian Amazon basin: teleconnections with sea surface temperature (SST) of 1976-2010Leila Limberger 28 September 2015 (has links)
A variabilidade climática é um objeto característico da Geografia já que anomalias positivas ou negativas de seus elementos, principalmente precipitação e temperatura, podem afetar de forma significativa a vida da população atingida. Na presente pesquisa, a variabilidade da vazão na bacia amazônica brasileira para o período de 1976 a 2010 é estudada por meio de técnicas estatísticas, tais como correlação linear, regressão linear simples e múltipla, análise de agrupamento e análise de ondeletas. Campos de componentes atmosféricos são apresentados para a compreensão da circulação atmosférica anômala que leva a anomalias de vazão. O objetivo é compreender com mais profundidade possíveis associações entre a variabilidade da vazão fluvial e da temperatura da superfície do mar, TSM, em regiões oceânicas específicas, reconhecendo-se para isso o acoplamento oceano-atmosfera que modula a variabilidade climática global. Este estudo compreendeu o uso de dados de vazão e precipitação do sistema Hidroweb/ANA, dados de TSM, radiação de onda longa e vento do conjunto de dados da Reanálise I, do NCEP/NCAR, e dados de precipitação do Global Precipitation Climatology Project, GPCP. A maior parte das análises considerou o tratamento de dados na escala mensal. O estudo verificou que há variabilidade espacial para a resposta da correlação linear entre a TSM e a vazão na bacia amazônica brasileira, verificada em cada uma das sub-regiões homogêneas definidas para esta pesquisa. Diferenças espaciais também foram verificadas nos resultados dos testes para tendência linear, identificando-se um padrão de tendência positiva da vazão na parte norte da bacia amazônica brasileira, e, negativa na porção sul. Sugere-se que a tendência negativa na porção sul esteja, em parte, associada à expansão das áreas agrícolas e, portanto, à intensificação do desmatamento. Cada uma das sub-regiões apresentou padrões espaciais de correlação linear diferenciados com os oceanos, mas, de forma geral, verifica-se que os eventos ENOS são importantes na definição da variabilidade da bacia amazônica, sendo mais efetivos nas anomalias de vazão das sub-regiões Norte, Amazonas-Foz e Sul, enquanto que a variabilidade da temperatura da superfície do mar no Atlântico Tropical Norte está bem associada à variabilidade da vazão nas sub-regiões Central e Oeste. A análise dos campos atmosféricos médios para anos caracterizados por ENOS neutros permitiu identificar que a sub-região Oeste apresentou resultados de influência de processos climáticos regionais que influenciaram anomalias positivas e negativas de vazão. Desta forma, a hipótese da tese de que, observando-se as particularidades de associação entre a temperatura da superfície do mar e a vazão fluvial para cada sub-região amazônica seria possível elaborar um modelo estocástico de previsão mais adequado a cada sub-região, sendo cada um mais apropriado a cada subregião, exprimindo maior acurácia e significância estatística, foi confirmada. Cada uma das sub-regiões consideradas apresenta intervalos de tempo preferenciais em que a correlação com a superfície dos oceanos é máxima. Assim, conclui-se que a bacia amazônica não pode ser considerada como um todo quanto à análise climática, já que foram confirmadas variabilidades espaciais de tendência linear dos dados de vazão, correlação entre vazão e precipitação e correlação com anomalias da temperatura da superfície do mar. / Climate variability is a characteristic object of geography, as positive or negative anomalies of its elements, especially precipitation and temperature may significantly affect the lives of the population. In this research, the variability of flow in the Brazilian Amazon basin for the period 1976-2010 is studied through statistical techniques such as linear correlation, simple and multiple linear regression, cluster analysis and wavelet analysis. Fields of atmospheric components are presented for comprehending the anomalous atmospheric circulation which leads to flow abnormalities. The objective is to understand more deeply possible associations between the variability of river flow and sea surface temperature, SST, in specific ocean regions, in order to recognize ocean-atmosphere coupling that modulates the global climate variability. This study has encompassed the use of flow and precipitation data of Hidroweb system/ANA, SST data, longwave radiation and wind of NCEP/NCAR Reanalysis I dataset, and precipitation data of Global Precipitation Climatology Project, GPCP. Most of the analyzes considered the treatment of data in the monthly scale. The study found that there is spatial variability to the response of the linear correlation between SST and the flow in the Brazilian Amazon basin seen in each one of the homogeneous subregions defined for this research. Spatial differences were also verified in the results of tests for linear trend, identifying a pattern of positive trend of the flow in the northern part of the Brazilian Amazon basin, and negative in the southern portion. It suggests that the negative trend in the southern portion is partly associated with the expansion of agricultural areas and therefore, the intensification of deforestation of forested areas. Each one of the subregions showed different spatial patterns of linear correlation with the oceans, but in general, ENSO events are important in defining the variability of the Amazon basin, being more effective in flow anomalies of North, Amazonas-Foz and South subregions, whereas the variability of sea surface temperature in the Tropical North Atlantic is well associated with the variability of flow in the Central and West subregions. The analysis of average atmospheric fields for years characterized by neutral ENSO was able to identify that the West subregion presented results of influence of regional climate processes which influenced anomalies of positive and negative flow. Thus, the hypothesis of the thesis that, by observing the association of the particularities between sea surface temperature and river flow for each Amazon subregion would be possible to develop a more appropriate stochastic model to each subregion, being each one more adequate to every subregion, expressing greater accuracy and statistical significance, was confirmed. Each one of the subregions considered presents preferential time intervals at which the correlation to the ocean surface is maximal. Therefore, it is concluded that the Amazon basin cannot be considered as a whole regarding its climate analysis, seeing that spatial variabilities of linear trend of flow data were confirmed, correlation between flow and precipitation and correlation with sea surface temperature anomalies.
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Variabilidade climática e correlação entre TSM e vazão fluvial nos rios Amazonas e Negro / Climate variability of the Atlantic and Pacific oceans and flow of the rivers Amazonas and NegroSérgio Orleans de Melo Gadelha 07 March 2012 (has links)
Variabilidade climática é um sistema complexo gerado pela participação de diversos atores e sua atuação na dinâmica atmosférica, a (TSM) Temperatura da Superfície do Mar tem papel fundamental de influencia nas diversas características dos índices climáticos: Southern Hemisphere Anular Mode Index (SAM), Southern Oscillation Index (SOI), El Nino / Oscilação Sul (ENSO), (TNA) Tropical North Atlantic Index, (PDO) Pacific Decada Oscillation, North Atlantic Oscillation Index (NAO). Os Índices com variações climáticas e suas implicações, possuem um espectro de atuação e formação do clima, que se inicia nos macro-sistemas através de suas influências extraterrestres, pelos períodos de atividade solar e outros, que nos convidam a buscar um melhor entendimento sobre o clima e suas forças resultantes. Portanto essa é uma pesquisa simplista, procura demonstrar os entes envolvidos nos processos de variabilidade climática, realçando muito mais o papel dos oceanos e sua influencia de correlação sobre os regimes fluviométricos, estimando definir também a sua grande importância e um melhor entendimento do ciclo hidrológico da escala espaço-temporal na região da bacia Amazônica, partindo de uma leitura do sistema atmosférico e sua influencia dinâmica resultante sobre o ciclo hidrológico. A pesquisa adquiriu através da (ANA) Agencia Nacional de Águas os dados de vazão fluvial dos rios Solimões/Amazonas e Negro, e junto ao Earth System Research Laboratory Physical Sciences Division da NOAA, foram adquiridos os valores de TSM e Índices climáticos, já para os dados de precipitação foram solicitados junto Centro de Previsão de Tempo e Estudos Climáticos (CPTEC/INPE). Todos estes dados foram tratados em processamento no Software GrADS e ainda compilados em FORTRAN, para a analise estatística através de (R) Analise e Planejamento de Experimentos, para fornecer os dados de correlação linear, Test-t e regressão linear com o objetivo de sustentar e apoiar a analise dos resultados que possam prognosticar a partir da defasagem entre as variáveis TSM e o comportamento resultante da vazão fluvial. / Climate variability is a complex system generated by the participation of various actors and their role in atmospheric dynamics, the Sea Surface Temperature(SST) plays a key role in influencing the several features of the climate indexes: Southern Hemisphere Cancel Index Mode (SAM), Southern Oscillation Index (SOI), El Nino / Southern Oscillation (ENSO), (TNA) Tropical North Atlantic Index (PDO) Pacific Decade Oscillation, North Atlantic Oscillation Index (NAO). The climate changes indexes and their implications have a spectrum in the activity and formation of the climate, which begins in macro-systems through their extraterrestrial influences, during periods of solar activity and others, who urges us to search a better understanding of the climate and its resultant forces. Therefore, this is a simplistic research, seeking to show the entities involved in the climate variability processes, emphasizing much more the role of the oceans and its influence on the fluvial routines correlation, and estimating also define a major and also a better understanding of the hydrological cycle spatiotemporal scale in the region of the Amazon basin, starting from a reading of the atmospheric system and its resulting dynamic influence on the hydrological cycle, acquired through this research (ANA) National Water Agency data flow of the rivers Solimões / Amazonas and Negro River, and with the Earth System Research Laboratory - Physical Sciences Division of NOAA, which acquired values of SST and climate indexes. The precipitation data was requested from Center for Weather Forecasting and Climate Studies (CPTEC / INPE). All these data were processed in the processing software GrADS and also compiled in FORTRAN for statistical analysis using (R) - Analysis and Design of Experiments, to provide data for linear correlation, T-test and linear regression in order to sustain and support the analysis of the results which could predict from the discrepancy between the SST variables and the resulting conduct of river flow.
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Índice oceânicos e sua relação com a precipitação pluvial do Rio Grande do Sul / Climate indices obtained from the SST of the Pacific and Atlantic oceans and its influence on rainfall variability in Rio Grande do SulSantos, Eliane Barbosa dos, Santos, Eliane Barbosa dos 01 March 2011 (has links)
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Previous issue date: 2011-03-01 / Certain climatc indexes were obtained from the SST of the Atlantic and Pacific Oceans, available at the ESRL/PSD/NOAA. / Foram determinados índices climáticos obtidos das TSMs dos oceanos Atlântico e Pacífico, disponíveis no site do ESRL/PSD/NOAA.
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