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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.
41

Vnitřní migrace Vietnamců v Česku a její zákonitosti / Internal migration of Vietnamese in Czechia and its regularities

Hönigová, Tereza January 2015 (has links)
Internal migration of Vietnamese in Czechia and its regularities Abstract: The purpose of this diploma thesis is to identify the key factors in the spatial distribution of the Vietnamese, characterize trends of their internal mobility in the Czech Republic and in two regions - Karlovarský and Ústecký. These both regions are characterized by a high concentration of Vietnamese in the Czech Republic. The thesis uses a questionnaire survey among Vietnamese migrants which took place on whole territory of the Czech Republic in 2013. Therefore we can describe their reasons for coming to our republic, trends in internal mobility and future migration plans. Part of the thesis is focused on relationship between the migration of Vietnamese and their employment or accommodation. Keywords: international migration, internal migration, immigrants, Vietnamese, spatial distribution of immigrants, Karlovarský region, Ústecký region, questionnaire survey
42

Prostorová distribuce jedinců sumce velkého Silurus glanis ovlivněná známostí / Spatial distribution of the European catfish Silurus glanis influenced by familiarity

Fořt, Martin January 2013 (has links)
One of the key elements of animal social behaviour is the recognition of individuals on the basis of previous experience. This relationship is called familiarity and affects individual's behaviour. We know many examples of familiarity-based behaviour among fish. Many results show that familiarity is advantageous. Familiar individuals are less aggressive, forage more, make more cohesive shoals and grow faster. We tested the influence of the familiarity on the spatial distribution of juvenile wels catfish Silurus glanis from two unfamiliar groups, which were held in separate tanks. In a laboratory experiment was the spatial distribution of individuals monitored in the artificial stream by using passive integrated transponders. Shelters, which were occupied by individuals, were placed in the stream. Two groups of fish were subsequently added into the experiment under conditions of limited or unlimited shelters. These groups came from the same tank (so they were familiar) or from different tanks (so they were unfamiliar). 1080 individuals were used in this experiment and over three million individual fish positions were recorded. We discovered changing levels of activity under different conditions. When we compared activity of original and additional individuals, we measured higher level of activity in...
43

Analyse spatiale et multi-échelle de la distribution des bactéries dans le sol et les sédiments / Multi-scale spatial analysis of microbial distribution in soil and sediment

Beaulne, Jean-Sébastien 20 November 2015 (has links)
Les bactéries ont colonisé toutes les niches écologiques de la planète. Plus précisément, les sols sont l’hôte de la plus grande biodiversité terrestre, la faune microbienne. Cette grande diversité de bactéries et leur relative ubiquité rendent difficile l’identification des variables contrôlant la distribution spatiale des bactéries vivant dans le sol. Comme les bactéries du sol jouent un rôle important dans les grands cycles biogéochimiques globaux, il est important de mieux comprendre les variables qui peuvent influencer la composition bactérienne des sols. Dans cette thèse, nous émettons l'hypothèse que l'hétérogénéité de la composition de la communauté bactérienne apparaît à la même échelle spatiale que l'hétérogénéité des propriétés physico-chimiques du sol. Afin de comprendre la relation entre la composition bactérienne des sols (à l’échelle d’une carotte de sol jusqu’à l’échelle d’une région entière du nord de la France) et les paramètres physico-chimiques du sol à différentes échelles spatiales, nous allons utiliser une approche intégrant des données issues d’analyses SIG (Système d’Information Géographique), d’analyses physico-chimiques du sol et d’analyses des communautés bactériennes du sol. A travers une suite de trois expérimentations, nous allons répondre à trois questions: Est-ce qu’une pression environnementale uniforme à une plus grande échelle (cm) peut atténuer l’hétérogénéité microbienne à micro-échelle? Est-ce que les variables ayant une distribution spatiale suivant un gradient géographique sont des variables structurant fortement la distribution spatiale des bactéries à l’échelle de ce même gradient? Est-ce que certains bio-indicateurs à grandes échelles peuvent intégrer des groupes de variables pour modéliser la distribution des bactéries pour une région entière ? / The bacteria have colonized all the niches of the planet. Specifically, soils are home of the largest terrestrial biodiversity, microbial fauna. This great diversity of bacteria and their relative ubiquity make it difficult to idendified variables driving the spatial distribution of bacteria living in the soil. As soil bacteria play a significant role in the main global biogeochemical cycles, it is important to better understand the variables that can influence bacterial composition of soils. In this thesis, we hypothesize that heterogeneity of the bacterial community composition appears at the same scale level as the heterogeneity of soil physicochemical properties. In order to understand the relationship of bacterial composition of soils (from core experiment to field study in large region in the northern France) and soil factors at different spatial scales, we will use an approach coupling GIS tools, soil physico-chemical analysis and 16S rRNA gene NGS. With Three set of experiment we will answer three questions: Can a uniform environmental pressure at a larger scale (cm) overcome microbial micro-scale heterogeneity? Are geographical gradients strong drivers of the microbial community structure at the scale of the gradient? Do large-scale geographical features that integrate groups of parameters model the differences in microbial community structure for an entire region?
44

Estudo da distribuição da atenção visuo-espacial em escolares / Investigation on the distribution of visuospatial attention among schoolchildren

Reis, Valeria Pinheiro 14 May 2010 (has links)
Atenção visual é a capacidade de processar melhor determinados estímulos em detrimento de outros. Tempos de Reação (TR) são medidas quantificáveis classicamente utilizadas para se estudar os efeitos atencionais a estímulos visuais. A atenção pode ser direcionada voluntariamente para outras regiões do espaço que não a determinada pelo ponto de fixação. Esse estudo teve por objetivo verificar o desenvolvimento da atenção visuoespacial em escolares por meio de medidas de TR em duas situações experimentais. Foram realizados dois experimentos psicofísicos em cinco grupos experimentais de acordo com suas faixas etárias (8, 9, 10, 12 e 15 anos de idade). O experimento I investigou a atenção explícita, que se caracteriza por ser a capacidade de alocar a atenção na região foveada. Já o experimento II estudou se a atenção visual poderia ser alocada em duas regiões não contíguas do espaço, caracterizando assim uma situação de atenção dividida. Como resultados observou-se que: (i) há diminuição dos TR em função da idade; (ii) na situação de atenção explícita, como esperado, todos os grupos foram capazes de alocar a atenção na região foveada.; (iii) na situação de atenção dividida, apenas o grupo de 15 anos foi capaz de apresentar divisão atencional. Esses resultados demonstram a viabilidade do método empregado no estudo da atenção em escolares e abre perspectivas de sua aplicação clínica em transtornos atencionais. / Visual attention is the ability to process certain stimuli in detriment of others. Reaction Times (RT) are the standard procedure to access the attentional effects on visual stimuli. Attention can be voluntary deployed to areas other than the gaze is. This study was aimed to investigate the development of visuo-spatial attention in school children through RT. Two experiments were employed and five groups, divided according to subjects age (8, 9, 10, 12 and 15 years old), were tested. Experiment I access overt attention whereas experiment II investigated a divided attention situation. Our findings showed: (i) there is a RT reduction as a function of age; (ii) all studied groups in the overt attention condition, as expected, were able to allocate attention where gaze was; (iii) only the 15 years old group was able to show divided attention in experiment II. These results showed the protocol\'s viability to access visual attention among children and open perspectives for its use in clinical settings such as attention disorders conditions.
45

Dinâmica temporal e espacial da mancha preta (Guignardia citricarpa) e quantificação dos danos causados à cultura dos citros. / Temporal and spatial dynamics of citrus black spot (Guignardia citricarpa) and quantification of the damages caused to citrus culture.

Sposito, Marcel Bellato 27 January 2004 (has links)
A mancha preta dos citros (MPC), incitada pelo fungo Guignardia citricarpa, causa lesões em frutos depreciando-os para a comercialização no mercado interno de fruta fresca, restringindo-os para a exportação e pode causar queda prematura. Para auxiliar nos estudos epidemiológicos, foi desenvolvida uma escala diagramática para a severidade da MPC que contempla os dois tipos de sintomas usualmente observados no campo, "mancha dura", cujos valores variam entre 0,5 e 49,0%, e "falsa melanose", cujos valores variam entre 1,1 e 68%. O grau de suscetibilidade das variedades cítricas ‘Hamlin’, ‘Pera’ e ‘Valência’ à MPC foi avaliado em pomar comercial, sob infecção natural. O modelo monomolecular ajustou-se às curvas de progresso da incidência e da severidade da doença para as três variedades. Não houve diferença estatística significativa entre as taxas de progresso da MPC, concluindo-se que as três variedades possuem o mesmo grau de suscetibilidade à doença. O agente causal da MPC em sua fase epidêmica forma ascósporos e conídios. Os ascósporos, formados em folhas em decomposição no solo, são disseminados a curtas e longas distâncias pela ação do vento. Os conídios, formados em ramos e frutos fixados à planta, são disseminados a curtas distâncias pela ação da água. O padrão de distribuição espacial de plantas com MPC foi avaliado pelo índice de dispersão e pela função K de Ripley. As plantas doentes mostraram-se agregadas independentemente da incidência da doença, indicando elevada importância da dispersão do inóculo a curtas distâncias. Avaliou-se, também, o padrão de distribuição de frutos sintomáticos dentro da planta, pelo índice de dispersão e pela forma binária da lei de Taylor. Pelo índice de dispersão 84% das plantas avaliadas mostraram agregação de frutos sintomáticos. Pela lei de Taylor concluiu-se que a agregação de frutos sintomáticos independe da incidência da doença na planta, sugerindo a participação dos conídios no incremento da doença em condições de campo. Estudou-se o efeito da supressão de ascósporos, pela retirada periódica de folhas cítricas em decomposição do campo e o de conídios, pela colheita antecipada de frutos de maturação tardia, na intensidade da MPC, por dois anos, em área com alta pressão de inóculo. Esses tratamentos reduziram a severidade da doença, no segundo ano de avaliação, entretanto não foram suficientes para controlá-la adequadamente. Estas medidas de sanitização são importantes no controle da MPC, devendo ser adotadas em conjunto com o controle químico. Danos causados pela redução na produtividade e perdas medidas pelo retorno financeiro foram avaliados em dois experimentos. Tratamentos cujo incremento na produção por hectare que, em comparação com a isenção de tratamento, excederam 100 caixas de 40,8 kg, foram rentáveis. A amostragem de áreas para diagnosticar a presença da MPC depende da finalidade da produção. Em áreas para exportação e mercado interno de fruta fresca deve-se avaliar todas as plant as do talhão, uma vez que esta doença é quarentenária e causa danos qualitativos. Em áreas para a indústria de suco cítrico concentrado, 285 plantas são suficientes para amostrar incidências superiores a 15% de MPC, em pomares médios de 2200 plantas. / The fungus Guignardia citricarpa is the causal agent of citrus black spot (CBS), which is a disease that become the fruits unsightly and unsuitable for the fresh fruit market. Besides, premature fruit drop may occur, reducing the productivity. A diagrammatic scale for the two symptoms of CBS (hard spot and false melanose) was developed to evaluate the severity and help in epidemiological studies of this disease. The susceptibility level of ‘Hamlin’, ‘Pera’ and ‘Valência’ sweet orange to CBS was evaluated in commercial orchard, under natural infection. The monomolecular model was fitted to the incidence and severity progress curves of the disease for the three sweet oranges. According to the progress curves, there was not significant difference among cultivars, showing that ‘Hamlin’, ‘Pera’ and ‘Valência’ sweet orange have similar susceptibility level to CBS. G. citricarpa in the epidemic phase produce ascospores and conidia. The ascospores, produced in leaves on soil, are disseminated by wind, while conidia, produced in plant twigs and fruits, are disseminated by water. The pattern of spatial distribution of CBS plants was evaluated by dispersion index and Ripley K function. The groups of symptomatic plants were distributed independently of disease incidence, suggesting that short distance dispersion of the inocullum could be the most important factor in distribution of the disease. The binary form of Taylor´s power law and dispersion index were used to evaluate the distribution of symptomatic fruits in the plant. According to dispersion index 84% o f the evaluated plants showed aggregation of symptomatic fruits, while by the Taylor´s power law the symptomatic fruits aggregation occurred independently of the incidence of plant disease, suggesting that the increase of disease in field conditions is related to conidia production. The effect of ascospore suppression on intensity of CBS was evaluated by removing citrus leaves from the orchard soil surface, while the conidia suppression was evaluated by early harvesting of late maturation fruits. These treatments, carried out during two years in a high inocullum incidence area, reduced the disease severity in the second year, but the satisfactory control was not observed. However, these treatments could be important in CBS control whether used in association with chemical control. Damages caused by yield reduction and losses of financial return were evaluated in two experiments. In relation to non-treated orchards, those treated orchards where the production/ha increased more than hundred boxes (40.8 kg each box) were considered profitable. The destination of the orange production (juice of fresh fruit market) are important for determine the size of samples to assess the CBS incidence. Since the G. citricarpa fungus is considered a quarentine organism that causes qualitative losses, in areas used for production of fresh fruit market whole orchard has to be evaluated. However, in areas used for production of fruits to concentrated orange juice, 285 plants sampled are enough to determinate the CBS incidence superior to 15%, in average orchards containing 2200 plants.
46

Partição de habitats entre os cervídeos do Parque Nacional do Iguaçu / Habitat partition among cervids in the Iguaçu National Park

Vogliotti, Alexandre 19 February 2009 (has links)
Este estudo avaliou os padrões que determinam a distribuição espacial entre as espécies simpátricas Mazama americana e Mazama nana ao longo do Parque Nacional do Iguaçu, sob os princípios da exclusão competitiva e da coexistência de espécies ecologicamente próximas. Foram formulados três potenciais modelos de partição de habitats para avaliar as relações entre a freqüência de ocorrências de cada uma das espécies com um conjunto de sete variáveis bióticas e abióticas mensuradas junto a cada unidade amostral. As ocorrências dos animais foram determinadas pela localização de amostras de fezes (unidades amostrais) encontradas ao longo do parque. As amostras foram identificadas geneticamente pela técnica do PCR/RFLP, com um marcador espécie-específico do gene do citocromo b do DNA mitocondrial extraído das amostras. No Modelo de Partição Parapátrica as freqüências de cada espécie (variável dependente) foram comparadas em função da altitude (m) acima do nível do mar, utilizada como indicativo dos tipos florestais considerados nesse modelo. No Modelo de Seleção Diferencial de Nichos, as espécies foram contrastadas com os valores de declividade (%), altura de dossel (m), densidade de cobertura vegetal vertical (%), densidade de cobertura horizontal (%) e o número de estratos vegetais (1-5). No Modelo de Partição Temporal, foram comparados os padrões de atividade de ambas as espécies, resultantes de um monitoramento com armadilhas fotográficas realizado nos extremos altitudinais do parque. Resultados significativamente discriminantes das freqüências de ocorrência das espécies foram observados em relação à altitude, densidade de cobertura vertical, horizontal e ao número de estratos vegetais, além de uma relação parcial com a declividade. A correlação observada entre a altitude e as variáveis de nicho (declividade, densidade vertical e horizontal) sugere um papel mais determinante do Modelo de Distribuição Parapátrica na modulação da distribuição de ambas as espécies na área em detrimento da Seleção Diferencial de Nichos. Na ausência de diferenças significativas entre os padrões circadianos de ambas as espécies, o Modelo de Partição Temporal também foi rejeitado. Uma análise adicional das dimensões (comprimento e largura) das síbalas fecais revelou uma grande sobreposição dos valores de ambas as espécies, rejeitando a validade de sua utilização como ferramenta para uma correta identificação dessas espécies na região. / This study evaluated the determinant patterns of spatial distribution among the sympatric species Mazama americana and Mazama nana in the Iguaçu National Park under the principles of competitive exclusion and coexistence of ecologically related species. Three potential models of habitat partition were proposed to evaluate the relations among the occurrence frequencies of the species and a set of seven biotic and abiotic variables measured near of each sample unit. Animal occurrences were determined by the location of fecal samples (sample units) found along the park. Samples were genetically identified by PCR/RFLP technique, using a species-specific cytochrome b gene marker of the mitochondrial DNA extracted from fecal samples. In the Parapatric Partition Model, frequencies of each species (dependant variable) were compared with respect to the altitude (m) above the sea level, used here as an index of the two forest types considered in this model. In the Niche Differential Selection Model, species were contrasted under its values of declivity (%), canopy height (m), canopy density (%), understory density (%) and the number of vegetal strata (1-5). In the Temporal Partition Model, the activity patterns obtained from a camera trap monitoring performed in both height extremes of the park were compared among the species. Significant results for differentiation of the species occurrence frequencies were observed for altitude, canopy and understory densities and number of vegetal strata, beyond a partial relation to declivity. An observed correlation between altitude and some of the niche variables (declivity, canopy and understory densities) suggests a more determinant role of the Parapatric Distribution Model to modulate the local distribution of both species, in detriment of the Niche Differential Selection one. The lack of significant differences between both daily activity patterns lead to the rejection of the Temporal Partition Model. An additional analysis of the fecal pellet dimensions (length and width) showed a high overlap of values from both species, refusing the validity of its use as secure identification tool for this species in the region.
47

Investigation of pollution coming from copper, lead, and zinc mining, and factors controlling mobility and bioavailability of pollutants at Ecton Hill, Staffordshire, UK

Al-Ibrahim, Zahid Omar Mustafa January 2017 (has links)
Former mining areas are well-known globally to be a significant anthropogenic source of contaminants being dispersed into the surrounding environment. Various human activities, including ore mineral mining, industrial activities, domestic waste production, and the agricultural application of fertilisers and pesticides, are likely to contribute to the release of huge amounts of potentially toxic metals into the ecosystem, which have harmful effects on the flora and fauna and on human health. Therefore, the main aim of this study is to evaluate the contamination that arises from some selected heavy metals (Cu, Pb, Zn, Mn, Cr, Ni, and V) in topsoil and floodplain samples from the Ecton mining area. Ecton Hill is located in the southern part of the Peak District, Staffordshire, England, and bounded by the River Manifold from the west. This area has been mined for sulphide minerals, which were extracted extensively from the 16th century until the mid-19th century; the area is currently being used for cattle rearing and agricultural purposes. Therefore, it would be worth finding out the extent to which the area has been polluted by the aforementioned metals. To this end, topsoil and floodplain samples were collected and analysed for their total concentrations using XRF technique and different granulometric classes (i.e. clay, silt, and sand) using a (Malvern Mastersizer Long Bed) laser granulometer with a presentation unit of MS-17. In addition, soil specific factors, including organic matter content, organic carbon, pH, Eh, and cation exchange capacity were also measured. Spatial distribution maps were constructed using a GIS approach for the metals studied over the study area. Contamination and ecological risk assessments were carried out via the geoaccumulation index (Igeo) and enrichment factors (EF) respectively. Moreover, collected soils for different land uses have been assessed using the UK government soil guidelines (i.e. ICRCL and CLEA's SGVs soil values). Furthermore, the bioavailability, leachability, and fractionation (using five-steps sequential extraction) of the metals in various soil phases were characterised using correlation matrix and principal component analysis (PCA) approaches. The GIS- based spatial analysis maps reveal that elevated concentrations of the metals are located around the sites of the mining waste in the area. The contamination assessment results indicate that Cu, Pb, Zn have a contamination degree ranging between strongly contaminated (class 4) and extremely contaminated (class 6). The results of the ecological assessment by enrichment factor (EF) show that Pb has the highest enrichment factor. The bioavailability results of the heavy metals under study, via EDTA, show that Cu, Pb, Zn have the highest bioavailable fractions. The regression analysis demonstrates that Mn gives the best fit regression equation with the highest R2 value of 0.825. The leachability results reveal that, of the seven heavy metals, Zn has the highest leachable value, whereas the lowest leachable was recorded for Cr. Speciation was measured using the five-steps procedure, and the results show that Cu, Pb and Zn are mainly associated with the organic matter fraction, whilst, Cr, Ni and V are associated with the residual fraction. The principal component analysis (PCA) revealed that oxides of Fe/Al, organic matter, and the clay and silt fractions are the main soil parameters responsible for binding heavy metals to the soil surfaces of the study area. Changing the redox potential conditions and acidification was investigated and the results indicate that such changes have significant effects on the release of heavy metals from the soil particles at Ecton Hill.
48

Avaliação do potencial produtivo do milho híbrido AGN-30A06 em espaçamentos e populações diferenciadas / Evaluation of mayze potential productivity (hybrid AGN-30A06) using different row spacing and plant population density

De Cesaro, Volmar 02 March 2009 (has links)
Com o objetivo de avaliar o potencial produtivo do milho híbrido AGN-30A06 em espaçamentos e populações diferenciadas, além de analisar o índice bromatológico do grão produzido visando verificar o efeito do manejo do nitrogênio empregado, foi conduzido um experimento de campo na área da Escola Agrotécnica Federal de Concórdia, em Concórdia, SC, utilizando o delineamento experimental de blocos casualizados, no esquema de parcelas subdivididas, com duas repetições. Foram utilizados os espaçamentos entre linhas de 0,45 m, 0,60 m e 0,80m com as populações de 60.000, 70.000 e 80.000 plantas por hectare. As maiores produtividades de grãos foram obtidas com o espaçamento de 0,45m. Dentre as três densidades populacionais, aquela que proporcionou um melhor resultado foi com 80.000 plantas por hectare e espaçamento entre linhas de 0,45m. Isso permite concluir que é possível aumentar a produtividade de grãos com o incremento de densidade de plantas sob o espaçamento reduzido. Quanto à bromatologia, pode-se concluir que: (i) quanto maior for a adubação, maior será o teor de óleo, menor será o teor de proteína, melhor será a qualidade dos grãos e menor será a incidência de doenças; e (ii) quanto menor for a adubação, maior será o teor de proteína, menor será o teor de óleo; e maior será a quantidade de grãos avariados. / With the purpose of evaluating the mayze potential yield (hybrid AGN-30A06) using different row spacing and plant population, in addition to analyzing the grain bromatological index and verifying the nitrogen management effect, a field experiment was carried out at \'Escola Agrotécnica Federal de Concórdia\', in Concórdia, State of Santa Catarina, Brazil, using the randomized block design (split-plot) with two replications. The following spacing between plant rows were used: 0.45 m, 0.60 m and 0.80 m with populations of 60,000, 70,000 and 80,000 plants per hectare. The higher values of grain productivities were obtained with the spacing between plant rows of 0.45 m. Among the three plant densities, 80,000 plants per hectare with spacing between plant rows of 0.45 m provided a better result. This indicates that it is possible to increase grain yield increasing plant density under reduced spacing between plant rows. Related to the bromatology, it was verified that: (i) high level of fertilization results higher oil content, lower protein content, better quality of grain and lower incidence of diseases and (ii) low level of fertilization results higher protein content, lower oil content and greater amount of damaged grains.
49

Identify the gas and solid flow structures within bubbling fluidized beds by using the PEPT technique

Li, Yunning January 2016 (has links)
Fluidized beds have been applied in many industrial processes (e.g. coal combustion, gasification and granulation) as an effective means for providing excellent gas and solids contact and mixing, as well as good heat transfer. Although research on the fluidized bed has been carried out for more than 70 years, uncertainties and difficulties still remain. These challenges exist primarily due to the complex and dynamic flow structure within fluidized beds and the lack of reliable measurement techniques. The positron emission particle tracking (PEPT) technique, developed at the University of Birmingham, enables individual particles to be tracked non-invasively in opaque three-dimensional (3-D) fluidized beds and offers favourable temporal and spatial resolutions. PEPT is considered to be a powerful tool for fluidized bed studies and was utilized in the current study to investigate the dynamic behaviour of solid and gas in fluidized beds. The experiments in this study were conducted in a 150-mm inner diameter (I.D.) column and operated in the bubbling fluidization regime at ambient conditions. The effects of various factors on the solid flow structure were examined: solid properties, superficial gas velocity, bed height-to-diameter aspect ratio (H/D) and pore size of the air distributor. The solid flow structure was classified into four patterns, namely patterns A, B, C and D, in which pattern C was newly observed in this thesis. The solid motion, bubble behaviour (i.e., bubble spatial distribution, bubble size and bubble rise velocity) and solid mixing were assessed for each flow pattern to understand their unique fluidization behaviours. This assessment was achieved by the development of three methods: a method to reconstruct bubble behaviours based on solid motion, and two methods for estimating the solid mixing profile in this thesis. The results were discussed and compared with the published literature. The bubble rise velocity and bubble size calculated in this research from the PEPT-measured data was in agreement with other research, particularly that of Kunii and Levenspiel, Yasui and Johanson, and Mori and Wen. Finally, a parameter was developed to predict and control flow patterns based on particle kinetic energy and various factors. The outcomes of this study advance the understanding of the complicated dynamics of bubbling fluidized beds and may benefit several industries in the enhancement of fluidized bed design and control to achieve desirable qualities and efficiencies.
50

Comunidade dormente e ativa de Cladocera em habitats da zona litorânea de lagoas marginais

Daré, Luana. January 2019 (has links)
Orientador: Jorge Laço Portinho / Resumo: O objetivo deste estudo foi conhecer a distribuição de Cladocera na zona litorânea de lagoas marginais, abrangendo a comunidade de forma completa, incluindo suas formas ativa e dormente, encontradas nos habitats que compõem essa região: coluna d’água, sedimento e banco de macrófitas. O estudo foi realizado em quatro lagoas marginais. Em cada lagoa foram definidas quatro estações de amostragem, em cada estação foram amostrados os três habitats, sedimento e macrófita (comunidade dormente), e coluna d’água abaixo das macrófitas (comunidade ativa). Ao investigar essa organização, observamos que a comunidade de Cladocera se distribui de forma heterogênea entre os três habitats. O banco de ovos no sedimento apresenta maior riqueza de espécies e maior número de ovos, quando comparado ao banco de ovos nas macrófitas. A comunidade ativa e os bancos de ovos apresentam elevada interação em relação à deposição e eclosão de ovos. O sedimento e a coluna d’água são os principais habitats onde as espécies se distribuem, e embora apresentem elevada similaridade entre si (táxons em comum), esses habitats isoladamente não são capazes de representar de forma completa a composição e riqueza da comunidade de Cladocera da região litorânea, pois cada um apresenta táxons de ocorrência exclusiva. / Abstract: The objective of this study was to know the distribution of Cladocera in littoral area of marginal lagoons, covering the community completely, including its active and dormant forms found in the habitats that make up this area: macrophytes bank, sediment and water column. The study was carried out in four marginal lakes. In each lake four sampling stations were defined, in each station the three habitats were sampled, sediment and macrophyte (dormant egg banks), and water column below the macrophytes (active community). In investigating this organization, we observed that the community of Cladocera is distributed heterogeneously among the three habitats. The egg bank in the sediment presents higher species richness and higher egg numbers when compared to egg banks in macrophytes. The active community and the egg banks present high interaction in relation to resting eggs deposition and hatching. The sediment and the water column are the main habitats where the species are distributed, and although they have a high similarity between them (common taxa), these habitats alone are not able to fully represent the composition and richness of the community of Cladocera in littoral area, since each one presents taxa of exclusive occurrence. / Mestre

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