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Population ecology of Euterpe edulis Mart. (Palmae)Matos, Dalva Maria da Silva January 1995 (has links)
1- The ecology of a population of the tropical palm tree Euterpe edulis Mart. was studied at the Municipal Reserve of Santa Genebra, Campinas (Sao Paulo, Brazil). This palm has been intensively exploited due to the quality of its heart of palm (palmito). The heart of palm corresponds to the apical meristem of the plant together with the developing new leaves. 2- The indiscriminate exploitation that this palm has been subject to over recent years in southern Sao Paulo may result in it becoming extinct in many forest fragments. The biodiversity of large animals in these forests has declined as a consequence of hunting, and the overexploitation of E. edulis has also led to a decline in the number of large frugiverous birds. The financial benefits generated by the sustainable exploitation of palmito can exceed those from a single extraction or those from forest conversion to agriculture. 3- The seed and seedling ecology of the population of E. edulis was examined. On average each plant produced approximately 1500 fruits and, there was a tendency for plants of intennediate size to be slightly more fecund. Most seeds were found in close proximity to adult plants; the distance of dispersal could be described by a negative power curve. Five species of birds belonging to the Family Turdidae were observed to feed on the fruits of E. edulis while on the tree, while subsequent dispersal along the gro':lnd was found to occur by water. The probability of surviving and growing to the next Sl~ class was inversely related to the number of seedlings. The maximum survival of seedlIngs and growth to the next size class occurred approximately 4 m from adult plants, indicating that the survival and growth of seedlings was suppressed in the immediate vicinity of conspecific adults. 4- The spatial pattern of the population of E. edulis, in the Municipal Reserve of Santa Genebra, was significantly clumped. The data indicate that the spatial distribution of individuals becomes less clumped with time as individuals develop. 5- The transition matrix analysis of the population revealed that the population is increasing at a rate of 14% year-I. The highest sensitivity was observed in the transition from size-class 1 (0-10 mm diameter) to class 2 (10.1 - 20 mm). According to the elasticity analysis, most of the value of the finite rate of population increase is accounted for by the probability of surviving and remaining in the same size class. The results from the haryesting simulations, indicate that it is possible to harvest E. edulis sustainably when harvesting is restricted to size class 6 plants (Le. reproductive adults). 6- The density-dependence observed for survival and growth of plants in the smallest size class was s~ong enough to affect the population dynamics of E. edulis. Elasticity analysis of the transItion matrix shows that the position of populations of E. edulis in G-L-F space moves towards the L apex of the demographic triangle as the density of plants increases.
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Water ingestion effects on gas turbine engine performanceNikolaidis, Theoklis 10 1900 (has links)
Although gas turbine engines are designed to use dry air as the working fluid,
the great demand over the last decades for air travel at several altitudes and
speeds has increased aircraft’s exposure to inclement weather conditions.
Although, they are required to perform safely under the effect of various
meteorological phenomena, in which air entering the engine contains water,
several incidents have been reported to the aviation authorities about power
loss during flight at inclement weather. It was understood that the rain ingestion
into a gas turbine engine influences the performance of the engine and
particular the compressor and the combustor.
The effects of water ingestion on gas turbine engines are aerodynamic,
thermodynamic and mechanical. These effects occur simultaneously and affect
each other. Considering the above effects and the fact that they are timedependent,
there are few gas turbine performance simulation tools, which take
into account the water ingestion phenomenon.
This study is a new research of investigating theoretically the water ingestion
effects on a gas turbine performance. It focuses on the aerodynamic and
mechanical effects of the phenomenon on the compressor and the combustor.
The application of Computational Fluid Dynamics (CFD) is the basic
methodology to examine the details of the flow in an axial compressor and how
it is affected by the presence of water. The calculations of water film thickness,
which is formed on the rotor blade, its motion (direction and speed) and the
extra torque demand, are provided by a code created by the author using
FORTRAN programming language. Considering the change in blade’s profile
and the wavy characteristics of the liquid film, the compressor’s performance
deterioration is calculated.
The compressor and combustor’s deterioration data are imported to a gas
turbine simulation code, which is upgraded to calculate overall engine’s
performance deterioration. The results show a considerable alteration in
engine’s performance parameters and arrive at the same conclusions with the
relevant experimental observations.
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Three-dimensional atmospheric modelling of emissions of nitrogen oxides from long-range civil subsonic aircraft at cruise altitudeLee, Shih-Ho January 1996 (has links)
Though nitrogen oxides (NOx ) emissions from aircraft make a relatively small contribution to the overall NOx emissions when compared to surface emissions, they constitute the only man-made pollutant at high altitude. Excessive NOx emissions might cause ozone depletion in the stratosphere and ozone increases in the troposphere, both topics of increasing environment concern in recent years. To tackle the problem of NOx emissions and their effects upon the environment, the spatial distribution of NOy (NOx + RN03) needs to be fully understood. The most significant source of NOx emissions is due to long range civil subsonic aircraft during their cruise phase. Detailed studies were performed for seven cases, including five single flight and two global scale scenarios, using the most widely used B747-400 aircraft which are powered by 4 three-shaft turbofan engines. Using models of aircraft performance, cruise phase NOx emissions are derived and employed as input to run a three-dimensional chemistry transport model. In order to achieve realistic results, all scenarios were carried out using a one-year period of simulation to study the transport and dispersion of NOy emitted from aircraft exhausts. For a better understanding of the atmospheric behaviour of NOy , two other cases were also carried out, a one-month simulation during both summer and winter situations. The results show that the upper troposphere may certainly be perturbed by aircraft NOx emissions at cruise altitude. The relative increase in NOx concentration is estimated to be of the order of 40% in the meridional average and up to 160% in regions covered with heavy air traffic such as Europe, the USA and the North Atlantic. This thesis investigates the quantity of long range civil subsonic aircraft NOx pollutants at cruise altitude and their subsequent implications for the upper troposphere. It discusses the concept of atmospheric NOy pollution chemistry, using computer programs developed for both total aircraft performance and 3-D chemistry transport modelling, and combinations thereof. Simulations have been conducted to predict the relationship between the NOx emissions and the environment. In addition, the thesis highlights the most important variables and derives a procedure to model the emissions from subsonic aircraft flight and to assess their impacts upon the atmosphere. Finally, some complicated problems which need further work are also mentioned.
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Hydrochemistry, soil chemistry and critical loads of selected upland moorland catchments, ScotlandMacPhee, Kirsty Potts January 1997 (has links)
This thesis presents precipitation, streamwater and soil chemistry from three upland catchments in Scotland situated upon granite parent material and receiving different deposition loadings. Marine ions are identified as important components of precipitation and streamwater at the two coastal sites (Bealach and Cardoon) and lesser importance at the inland site (Allt a'Mharcaidh). Similar ratios of Na:Ca:Mg in precipitation and streamwater indicate the importance of catchment hydrology and organic soils in controlling streamwater chemistry. Input/output budgets indicate SO4-S and H+ loss from the Cardoon (a region of high acid deposition inputs) compared with the other two less polluted sites which exhibit SO4-S and H + retention. The SO4-S loss from the Cardoon is also associated with a high DOC flux in streamwater. In all three catchments differences were found between published critical load values and those calculated as part of this study. Seasonal and annual variations in critical loads for freshwaters at all sites indicate sampling for the national mapping exercise does not reflect the most acid-sensitive periods. Streamwater was also more sensitive than standing waters, with lower critical load values. Soil critical load values were lower than published soil critical load values as well as freshwater critical loads calculated in this study. Inclusion of marine-derived base-cations in PROFILE calculations of soil critical loads increased values markedly (1 keq ha-1yr -1) at the 2 coastal sites. Soil critical load varied little between horizons, suggesting that the identification of hydrologically important mineral horizon was not important. Lowest critical load values for freshwaters were controlled by the organic horizons which are not considered in PROFILE calculations. The implications of the omission of organic horizons from critical load calculations for soil in upland catchments are discussed and the use of critical loads at a catchment based level addressed.
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The Formation of Stratus in RainFrey, Wiebke January 2005 (has links)
Data analysis of SYNOP observations was made for investigation of stratus formation in rain. The aim was to find connections between meteorological parameters in the different states of rain to develop a forecast method. 1594 cases of rainfall from the four stations Luleå, Uppsala, Linköping and Såtenäs, Sweden were analysed, 974 cases include stratus formation in rain and the other 620 cases are without stratus formation. The investigation focused on the meteorological parameters wind direction, wind speed, relative humidity, visibility, cloud base height and rain intensity. As rain intensity was not explicitly included in the SYNOP observations it could not be taken as a governing parameter, but classification of the data into four groups of different rain intensity was possible. Also time was a parameter for the investigation. The results show that a more detailed investigation should be made to eliminate several influences of other parameters, for example of radiation or soil conditions. Thus it was too difficult to develop a forecast method for the formation of stratus in rain, but suggestions for further investigations and the development of a numerical model only are made. / En dataanalys av SYNOP-observationer genomfördes för undersökning av stratusbildning i regn. Målet var att hitta samband mellan de meteorologiska parametrarna i olika regntillstånden för att utveckla en prognosmetod. 1594 regntillfällen från fyra stationer, Luleå, Uppsala, Linköping och Såtenäs, analyserades. 974 tillfällen innehåller stratusbildning i regn och de andra 620 tillfällena visar ingen stratusbildning. Undersökningen koncentrerades på de meteorologiska parametrarna vindriktning, vindhastighet, relativ fuktighet, sikt, molnhöjd och regnintensitet. Eftersom regnintensiteten inte var beskriven i SYNOP-observationer kunde den inte tas med som parameter i analysena. Det gick att indela datan i fyra grupper med olika regnintensitet. Tid var också en parameter i den här unders- ökningen. Resultater visar att det behövs en noggrannare undersökning för kunna eliminera påverkan av andra parametrar som till exempel strålning eller marktillstånd. Det var därför för svårt att utveckla en prognosmetod för stratusbildning i regn, så förslag har bara gjorts för vidare undersökningar och utveckling av en numerisk modell. / Für die Untersuchung der Stratusbildung im Regen wurde eine Analyse von SYNOP-Daten durchgeführt. Ziel war es, Zusammenhänge zwischen meteorologischen Parametern in den verschiedenen Stadien von Regen zu finden, um eine Vorhersagemethode zu entwickeln. Es wurden 1594 Regen- F¨alle von den Stationen Luleå, Uppsala, Linköping und Såtenäs in Schweden analysiert, von denen 974 Fälle Stratusbildung in Regen beinhalten. Die anderen 620 Fälle zeigen keine Stratusbildung. Die Untersuchung konzentrierte sich auf die meteorologischen Parameter Windrichtung, Windgeschwindigkeit, relative Feuchte, Sicht, Wolkenhöhe und Regenintensität. Da die Regenintensität nicht direkt in den SYNOP Beobachtungen gemessen wurde, konnte sie nicht als steuernder Parameter verwendet werden, sondern diente nur zur Einteilung der Daten in vier Gruppen verschiedener Regenintensität. Die Zeit ging als ein weiterer Parameter in diese Untersuchung ein. Die Ergebnisse zeigen, dass eine genauere Untersuchung durchgeführt werden sollte, um unterschiedliche Einflüsse anderer Parameter, wie zum Beispiel Strahlung oder Bodenbeschaffenheit, auszuschließen. Wegen der zu großen Unsicherheiten war es zu schwer, eine Prognosemethode f¨ur die Stratusbildung im Regen zu entwickeln. Deswegen wurden Vorschläge für weitere Untersuchungen und f¨ur die Entwicklung eines numerischen Modells gegeben.
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Clouding power? Rain-control, Space, Landscapes and Ideology in Shashe-Limpopo State FormationSchoeman, Maria Hendrieka 14 February 2007 (has links)
Student Number : 8905619P -
PhD thesis -
School of Geography, Archaeology and Environmental Studies -
Faculty of Humanities / In this thesis I identify and clarify the archaeological signature of rain-control sites
in the Shashe-Limpopo Confluence Area (SLCA). I use a landscape-based
approach to investigate rain-control in the ideology of SLCA farming
communities. I investigate the archaeology of ritual by viewing rain-control as
materialised ideology. Using this insight, I examine the material culture and
spatial manifestation of rain-control, the transition from ritual to residential sites,
and how these transitions articulated with the ritualised landscape.
Specifically, I explore the local manifestation of rain-control and its relationship
with the ideologies of farming communities in the period leading up to SLCA state
formation, between AD 1000 and AD 1250. I also scrutinize the relationship of
the Leopard’s Kopje elite with hunter-gatherers and other farming people on the
same landscape, as this relationship was partly grounded in ritual and raincontrol.
Furthermore, this thesis explores the ideological roots of the Mapungubwe state.
The ideology manifest in the location of the Mapungubwe royal residential area
germinated during the K2 occupation. In this period rain-control was slowly
removed from nature and located in farmer society. The final step in this course
was nationalising rain-control and locating it on Mapungubwe hill. Initially,
however, rain-controllers resisted this centralisation.
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Valuing forests in tropical landscapes in the context of REDD+Wilebore, Rebecca January 2015 (has links)
No description available.
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Diversidade de vespas sociais (Hymenoptera, vespidae) na Mata Atlântica do litoral norte do estado de São Paulo /Togni, Olga Coutinho. January 2009 (has links)
Orientador: Edilberto Giannotti / Banca: Fábio Prezoto / Banca: Maria José de Oliveira Campos / Resumo: A Mata Atlântica é um ecossistema muito relevante para a biologia da conservação e possui uma das maiores diversidades de espécies do continente, inclusive a de vespas sociais. Este grupo de insetos, que no Brasil está representado pelos Polistinae, causa grandes impactos nos ecossistemas, já que as vespas são importantes predadoras e coletoras de néctar. Tendo em vista que o inventário das espécies de uma área é o ponto inicial para a sua preservação, o objetivo do estudo foi efetuar um levantamento da diversidade de vespas sociais da Mata Atlântica da Serra do Mar do litoral norte do estado de São Paulo, enfatizando a importância desse grupo para avaliações de impacto ambiental e de efeitos de fragmentação florestal da região. Além disso, foi possível comparar a eficiência das metodologias utilizadas, verificando se ocorre preferência das vespas pelo conteúdo das armadilhas. As coletas foram realizadas na Fazenda Angelim Rainforest de maio de 2007 a maio de 2008, utilizando armadilhas atrativas de garrafa PET e coleta ativa. Foram encontradas 21 espécies pertencentes a oito gêneros e, dentre elas, algumas são raras na região sudeste do país, como Mischocyttarus parallelogrammus e Polybia catillifex. As espécies mais freqüentes foram Agelaia angulata (64,31%), A. sp. prox. centralis (10,08%) e Angiopolybia pallens (8,49%). Observou-se correlação entre a riqueza das espécies e a umidade relativa do ar. Analisando os distintos ambientes, verificou-se maior riqueza, abundância e índice de diversidade de Margalef na área antropizada (A=793, R=14, DMg=4,4839, H'=1,08), mas a maior diversidade obtida pelo índice de Shannon-Wiener foi na área de mata fechada (A=174, R=8, DMg=3,1242, H'=1,17). As armadilhas com atrativo glucídico obtiveram maior riqueza, igual a 16 espécies ou 76,19% da riqueza total coletada. As armadilhas... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The Atlantic Rain Forest is very relevant for conservation biology and has one of the greatest biodiversity in the continent, including social wasps diversity. This group of insects, which in Brazil is represented by Polistinae, causes major impacts on ecosystems, because the wasps are important predators and collectors of nectar. Bearing in mind that the inventory of species in an area is the starting point for its preservation, the goal of this study was to perform a survey of the social wasps diversity of the Atlantic Forest on the north coast of São Paulo State, emphasizing the importance of this group for environmental impact assessments and the effects of forest fragmentation in the region. Furthermore, it was possible to compare the efficiency of the methodologies, verifying if there is a preference of the wasps for the contents of the traps. The collections were made in Fazenda Angelim Rainforest from May 2007 to May 2008, using attractive PET bottles traps and active searching. We found 21 species belonging to eight genera and among them; some are rare in the southeast region of the country, such as Mischocyttarus parallelogrammus and Polybia catillifex. The most frequent species were Agelaia angulata (64.31%), A. sp. prox. centralis (10.08%) and Angiopolybia pallens (8.49%). Correlation was observed between species richness and relative air humidity. When analyzing the different environments, it was possible to verify a greater richness, abundance and Margalef diversity index in the anthropic area (A= 793, R= 14, DMg= 4.4839, H= 1.08), but the greatest diversity obtained by Shannon-Wiener index was in the area of dense vegetation (A= 174, R= 8, DMg= 3.1242, H'= 1.17). The traps with glucidic attractive obtained greater richness, equal to 16 species or 76.19% of total richness collected. Traps with protein content were the least effective (six species, 28.57% of total richness)... (Complete abstract click electronic access below) / Mestre
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Restauration d'images par temps de brouillard et de pluie : applications aux aides à la conduite / Image restoration during foggy and rainy weather : applications for driver assistance systemsHalmaoui, Houssam 30 November 2012 (has links)
Les systèmes d'aide à la conduite (ADAS) ont pour objectif d'assister le conducteur et en particulier d'améliorer la sécurité routière. Pour cela, différents capteurs sont généralement embarqués dans les véhicules afin, par exemple, d'avertir le conducteur en cas de danger présent sur la route. L'utilisation de capteurs de type caméra est une solution économiquement avantageuse et de nombreux ADAS à base de caméra voient le jour. Malheureusement, les performances de tels systèmes se dégradent en présence de conditions météorologiques défavorables, notamment en présence de brouillard ou de pluie, ce qui obligerait à les désactiver temporairement par crainte de résultats erronés. Hors, c'est précisément dans ces conditions difficiles que le conducteur aurait potentiellement le plus besoin d'être assisté. Une fois les conditions météorologiques détectées et caractérisées par vision embarquée, nous proposons dans cette thèse de restaurer l'image dégradée à la sortie du capteur afin de fournir aux ADAS un signal de meilleure qualité et donc d'étendre la gamme de fonctionnement de ces systèmes. Dans l'état de l'art, il existe plusieurs approches traitant la restauration d'images, parmi lesquelles certaines sont dédiées à nos problématiques de brouillard ou de pluie, et d'autres sont plus générales : débruitage, rehaussement du contraste ou de la couleur, "inpainting"... Nous proposons dans cette thèse de combiner les deux familles d'approches. Dans le cas du brouillard notre contribution est de tirer profit de deux types d'approches (physique et signal) afin de proposer une nouvelle méthode automatique et adaptée au cas d'images routières. Nous avons évalué notre méthode à l'aide de critères ad hoc (courbes ROC, MSE, contraste visibles à 5 %, évaluation sur ADAS) appliqués sur des bases de données d'images de synthèse et réelles. Dans le cas de la pluie, une fois les gouttes présentes sur le pare-brise détectées, nous reconstituons les parties masquées de l'image à l'aide d'une méthode d'"inpainting" fondée sur les équations aux dérivées partielles. Les paramètres de la méthode ont été optimisés sur des images routières. Enfin, nous montrons qu'il est possible grâce à cette approche de construire trois types d'applications : prétraitement, traitement et assistance. Dans chaque famille, nous avons proposé et évalué une application spécifique : détection des panneaux dans le brouillard ; détection de l'espace navigable dans le brouillard ; affichage de l'image restaurée au conducteur. / Advanced Driver Assistance Systems (ADAS) are designed to assist the driver and in particular to improve road safety. For this purpose, various sensors are typically embedded in vehicles in order, for example, to alert the driver in case of imminent danger on the road. The use of camera type of sensor is a cost-effective solution and many ADAS based on camera are being created. Unfortunately, the performance of such systems decrease drastically in the presence of adverse weather conditions, especially in the presence of fog or rain, which could oblige to turn off the systems temporarily in order to avoid erroneous results. While, it is precisely in these difficult circumstances that the driver would potentially need the most to be assisted. Once the weather conditions detected and characterized by embedded vision, we propose in this thesis to restore the degraded image to provide a better signal to the ADAS and thus extend the operation range of these systems. In the state of the art, there are several approaches dealing with images restoration, some of which are dedicated to our fog and rain problem and others are more general : denoising, contrast or color enhancement, inpainting... We propose in this work to combine the two families of approaches. In the case of fog our contribution is to take advantage of both approaches (physical and signal) to propose a new automatic method adapted to the case of road images. We evaluated our method using ad hoc criteria (ROC curves, visible contrast to 5%, assessment on ADAS) applied to databases of synthetic and real images. In case of rain, once the drops present on the windshield are detected, we reconstruct the hidden parts of the image using a method of inpainting based on partial differential equations. The method parameters have been optimized on road images. Finally, we show that it is possible with this approach to build three types of applications : preprocessing, processing and assistance. In every family, we have proposed and evaluated a specific application : traffic signs detection during foggy weather; detection of free space in fog conditions and display of the restored image to the driver.
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Cluster Analysis for Acid Rain Data in NorwayGhafourian, Ali 01 May 1983 (has links)
This paper gives a description of three well known clustering methods, and discusses the advantages and disadvantages of each. Then, the results of these three clustering methods are compared through examining them on a specific set of data.
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