17 research outputs found

    Otimização da altura de uma barragem de terra homogênea.

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    Nowadays the dimension of a reservoir should consider the determination of the minimum capacity that the reservoir has to possess, necessary to regularize the yield based on the demand. One of the main parameters that characterize a dam is its height that, inside of an economical analysis, influences the cost of the reservoir water and according to an analysis of hidrological efficiency, influences the regularized. The present work proposes a methodology for the previous dimension of a reservoir, that uses numeric techniques of optimization, for determination of the height of a dam, with the objective of minimizing the cost of the water. This procedure was applied to the Rosário reservoir built by PROURB (Project of Urban Development and Administration of the water resources of the State of Ceará). The height found for the reservoir was of 20.70 m, with yield of 29.73 hm3/ano resulting in a cost of the water of R13.97/1000m3.Atualmente,odimensionamentodeumabarragempartedadeterminac\ca~odacapacidademıˊnimaqueoreservatoˊriotemquepossuir,necessaˊriapararegularizarumaquantidadequeeˊestipuladacombasenademandanecessaˊriapararegia~o,fixando,posteriormente,suaaltura,independentedocustodeconstruc\ca~o.Umdospara^metrosprincipaisquecaracterizamumabarragemeˊasuaaltura,que,dentrodeumaanaˊliseecono^mica,influencianocustodoreservatoˊrioedentrodeumaanaˊlisedeeficie^nciahıˊdrica,influencianavaza~oregularizada.Opresentetrabalhopropo~eumametodologiaparaopreˊdimensionamentodeumabarragem,queutilizateˊcnicasnumeˊricasdeotimizac\ca~oparadeterminac\ca~odasuaaltura,tendo,comoobjetivo,minimizarocustodaaˊgua.EsteprocedimentofoiaplicadonabarragemdoRosaˊrio,reservatoˊrioconstruıˊdopeloPROURB(ProjetodeDesenvolvimentoUrbanoeGesta~odosRecursosHıˊdricosdoEstadodoCearaˊ).Encontrouseumaalturaoˊtimaglobalparaala^minadaˊguade20,70m,comumavaza~oderegularizac\ca~ode29,73hm3/anoresultandonumcustodaaˊguadeR 13.97/1000m3.Atualmente, o dimensionamento de uma barragem parte da determinação da capacidade mínima que o reservatório tem que possuir, necessária para regularizar uma quantidade que é estipulada com base na demanda necessária para região, fixando, posteriormente, sua altura, independente do custo de construção. Um dos parâmetros principais que caracterizam uma barragem é a sua altura, que, dentro de uma análise econômica, influencia no custo do reservatório e dentro de uma análise de eficiência hídrica, influencia na vazão regularizada. O presente trabalho propõe uma metodologia para o pré-dimensionamento de uma barragem, que utiliza técnicas numéricas de otimização para determinação da sua altura, tendo, como objetivo, minimizar o custo da água. Este procedimento foi aplicado na barragem do Rosário, reservatório construído pelo PROURB (Projeto de Desenvolvimento Urbano e Gestão dos Recursos Hídricos do Estado do Ceará). Encontrou-se uma altura ótima global para a lâmina d’água de 20,70 m, com uma vazão de regularização de 29,73 hm3/ano resultando num custo da água de R 13,97/1000m3

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    Pervasive gaps in Amazonian ecological research

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    ATLANTIC EPIPHYTES: a data set of vascular and non-vascular epiphyte plants and lichens from the Atlantic Forest

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    Epiphytes are hyper-diverse and one of the frequently undervalued life forms in plant surveys and biodiversity inventories. Epiphytes of the Atlantic Forest, one of the most endangered ecosystems in the world, have high endemism and radiated recently in the Pliocene. We aimed to (1) compile an extensive Atlantic Forest data set on vascular, non-vascular plants (including hemiepiphytes), and lichen epiphyte species occurrence and abundance; (2) describe the epiphyte distribution in the Atlantic Forest, in order to indicate future sampling efforts. Our work presents the first epiphyte data set with information on abundance and occurrence of epiphyte phorophyte species. All data compiled here come from three main sources provided by the authors: published sources (comprising peer-reviewed articles, books, and theses), unpublished data, and herbarium data. We compiled a data set composed of 2,095 species, from 89,270 holo/hemiepiphyte records, in the Atlantic Forest of Brazil, Argentina, Paraguay, and Uruguay, recorded from 1824 to early 2018. Most of the records were from qualitative data (occurrence only, 88%), well distributed throughout the Atlantic Forest. For quantitative records, the most common sampling method was individual trees (71%), followed by plot sampling (19%), and transect sampling (10%). Angiosperms (81%) were the most frequently registered group, and Bromeliaceae and Orchidaceae were the families with the greatest number of records (27,272 and 21,945, respectively). Ferns and Lycophytes presented fewer records than Angiosperms, and Polypodiaceae were the most recorded family, and more concentrated in the Southern and Southeastern regions. Data on non-vascular plants and lichens were scarce, with a few disjunct records concentrated in the Northeastern region of the Atlantic Forest. For all non-vascular plant records, Lejeuneaceae, a family of liverworts, was the most recorded family. We hope that our effort to organize scattered epiphyte data help advance the knowledge of epiphyte ecology, as well as our understanding of macroecological and biogeographical patterns in the Atlantic Forest. No copyright restrictions are associated with the data set. Please cite this Ecology Data Paper if the data are used in publication and teaching events. © 2019 The Authors. Ecology © 2019 The Ecological Society of Americ

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

    Boundary element method applied to the analysis of tunnel using two-dimensional approach models

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    O método dos elementos de contorno (MEC) surgiu como uma poderosa alternativa ao método dos elementos finitos (MEF) principalmente em casos como problemas de concentração de tensões ou onde o domínio se estende para o infinito. Em virtude das potencialidades já identificadas do MEC para a solução de problemas da geotecnia, em especial para problemas de túneis, este trabalho tem como objetivo desenvolver um programa que seja capaz de analisar as variáveis envolvidas na construção de túneis profundos através de um modelo numérico bidimensional baseado no MEC, implementando técnicas numéricas tais como: subelementação, técnica da sub-região e modelagem de inclusão e enrijecedores. O modelo numérico bidimensional foi calibrado para considerar o efeito tridimensional do problema de túneis no que se refere ao avanço da frente de escavação, para dois casos a saber: i) túneis sem suporte e ii) túneis com suporte. Os resultados mostraram grande precisão quando comparados com os resultados analíticos mesmo utilizando um número pequeno de elementos, provocando uma redução significativa no tempo de processamento se comparado com outros métodos. A técnica da subelementação produziu uma suavização nos resultados dos pontos internos localizados muito próximos do contorno. A técnica da sub-região, bem como a modelagem de inclusão e enrijecedores apresentaram resultados consistentes dando ao programa uma versatilidade maior. Na calibração dos parâmetros para a consideração do efeito tridimensional na escavação de túneis sem suporte, foi proposto o método da redução do carregamento com a construção do perfil de deformação longitudinal do túnel - LDP (Longitudinal Deformation Profile). Para a escavação de túneis com suporte foram propostos quatro métodos de análise: i) método da redução do carregamento sobre o túnel, ii) método da redução de rigidez do suporte, iii) método do acréscimo do carregamento sobre o túnel e iv) método do alívio de carga sobre o suporte. Todos esses métodos foram desenvolvidos a partir do modelo Kappa (\'kapa\'), elaborado neste trabalho a partir dos resultados encontrados na simulação numérica tridimensional realizado nos programas BEFE e BEFE++, e comparado com o modelo de Schwartz e Einstein. Por fim, o método para a construção do gráfico de deslocamento radial para túneis circulares suportados, considerando o atraso na instalação do suporte, utilizando um método numérico ou resultado analítico do estado plano de deformação se mostra como uma alternativa simples para análise do efeito tridimensional contido no problema de túneis.The boundary element method (BEM) has appeared as a powerful alternative to the finite element method (FEM) mainly in the cases where a good accuracy is required, as for problems with strain or stress concentration and problems with domain extending to infinite. The objective of this work is to develop a formulation and the corresponding computational code to analyse the variables in a design of deep tunnels, using a improved BEM two-dimensional numerical model, in which the following techniques were implemented: sub-elementation, sub-region technique, reinforcements introduced by modifying locally the domain rigidity. The two-dimensional model was calibrated to take into account the three-dimensional effects appearing around the tunnel face advance for two cases: i) tunnel without support and ii) tunnel with support. The results showed good accuracy when compared with analytical results even when obtained by using coarse discretizations and therefore requiring less computer time in comparison with other numerical procedures. The sub-elementation technique has smoothed the results for internal points near the boundary. The sub-region technique and the reinforcement inclusions lead to accurate making the computer code reliable. For the parameter calibration to take into account the three-dimensional effects applied to non lined tunnels the method of loading reductions was proposed obtaining a tunnel longitudinal deformation profile - LDP. For the excavation of lined tunnels four methods of analysis were proposed: i) load reduction model, ii) reduction support stiffness model, iii) additional load model, and iv) decrease of lining load model. All these methods were developed from the kappa (\'kapa\') model, developed in this work using three-dimensional results obtained by using the computational systems BEFE and BEFE++ and compared with the Schwartz-Einstein method. Finally the method used to build the radial displacement graphic for lined circular tunnels, taking into account the support insertion delay, using either a numerical method or plane strain analytical solutions, was developed

    Otimização da altura de uma barragem de terra homogênea.

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    Nowadays the dimension of a reservoir should consider the determination of the minimum capacity that the reservoir has to possess, necessary to regularize the yield based on the demand. One of the main parameters that characterize a dam is its height that, inside of an economical analysis, influences the cost of the reservoir water and according to an analysis of hidrological efficiency, influences the regularized. The present work proposes a methodology for the previous dimension of a reservoir, that uses numeric techniques of optimization, for determination of the height of a dam, with the objective of minimizing the cost of the water. This procedure was applied to the Rosário reservoir built by PROURB (Project of Urban Development and Administration of the water resources of the State of Ceará). The height found for the reservoir was of 20.70 m, with yield of 29.73 hm3/ano resulting in a cost of the water of R13.97/1000m3.Atualmente,odimensionamentodeumabarragempartedadeterminac\ca~odacapacidademıˊnimaqueoreservatoˊriotemquepossuir,necessaˊriapararegularizarumaquantidadequeeˊestipuladacombasenademandanecessaˊriapararegia~o,fixando,posteriormente,suaaltura,independentedocustodeconstruc\ca~o.Umdospara^metrosprincipaisquecaracterizamumabarragemeˊasuaaltura,que,dentrodeumaanaˊliseecono^mica,influencianocustodoreservatoˊrioedentrodeumaanaˊlisedeeficie^nciahıˊdrica,influencianavaza~oregularizada.Opresentetrabalhopropo~eumametodologiaparaopreˊdimensionamentodeumabarragem,queutilizateˊcnicasnumeˊricasdeotimizac\ca~oparadeterminac\ca~odasuaaltura,tendo,comoobjetivo,minimizarocustodaaˊgua.EsteprocedimentofoiaplicadonabarragemdoRosaˊrio,reservatoˊrioconstruıˊdopeloPROURB(ProjetodeDesenvolvimentoUrbanoeGesta~odosRecursosHıˊdricosdoEstadodoCearaˊ).Encontrouseumaalturaoˊtimaglobalparaala^minadaˊguade20,70m,comumavaza~oderegularizac\ca~ode29,73hm3/anoresultandonumcustodaaˊguadeR 13.97/1000m3.Atualmente, o dimensionamento de uma barragem parte da determinação da capacidade mínima que o reservatório tem que possuir, necessária para regularizar uma quantidade que é estipulada com base na demanda necessária para região, fixando, posteriormente, sua altura, independente do custo de construção. Um dos parâmetros principais que caracterizam uma barragem é a sua altura, que, dentro de uma análise econômica, influencia no custo do reservatório e dentro de uma análise de eficiência hídrica, influencia na vazão regularizada. O presente trabalho propõe uma metodologia para o pré-dimensionamento de uma barragem, que utiliza técnicas numéricas de otimização para determinação da sua altura, tendo, como objetivo, minimizar o custo da água. Este procedimento foi aplicado na barragem do Rosário, reservatório construído pelo PROURB (Projeto de Desenvolvimento Urbano e Gestão dos Recursos Hídricos do Estado do Ceará). Encontrou-se uma altura ótima global para a lâmina d’água de 20,70 m, com uma vazão de regularização de 29,73 hm3/ano resultando num custo da água de R 13,97/1000m3

    ATLANTIC BIRD TRAITS: a data set of bird morphological traits from the Atlantic forests of South America

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    Scientists have long been trying to understand why the Neotropical region holds the highest diversity of birds on Earth. Recently, there has been increased interest in morphological variation between and within species, and in how climate, topography, and anthropogenic pressures may explain and affect phenotypic variation. Because morphological data are not always available for many species at the local or regional scale, we are limited in our understanding of intra- and interspecies spatial morphological variation. Here, we present the ATLANTIC BIRD TRAITS, a data set that includes measurements of up to 44 morphological traits in 67,197 bird records from 2,790 populations distributed throughout the Atlantic forests of South America. This data set comprises information, compiled over two centuries (1820–2018), for 711 bird species, which represent 80% of all known bird diversity in the Atlantic Forest. Among the most commonly reported traits are sex (n = 65,717), age (n = 63,852), body mass (n = 58,768), flight molt presence (n = 44,941), molt presence (n = 44,847), body molt presence (n = 44,606), tail length (n = 43,005), reproductive stage (n = 42,588), bill length (n = 37,409), body length (n = 28,394), right wing length (n = 21,950), tarsus length (n = 20,342), and wing length (n = 18,071). The most frequently recorded species are Chiroxiphia caudata (n = 1,837), Turdus albicollis (n = 1,658), Trichothraupis melanops (n = 1,468), Turdus leucomelas (n = 1,436), and Basileuterus culicivorus (n = 1,384). The species recorded in the greatest number of sampling localities are Basileuterus culicivorus (n = 243), Trichothraupis melanops (n = 242), Chiroxiphia caudata (n = 210), Platyrinchus mystaceus (n = 208), and Turdus rufiventris (n = 191). ATLANTIC BIRD TRAITS (ABT) is the most comprehensive data set on measurements of bird morphological traits found in a biodiversity hotspot; it provides data for basic and applied research at multiple scales, from individual to community, and from the local to the macroecological perspectives. No copyright or proprietary restrictions are associated with the use of this data set. Please cite this data paper when the data are used in publications or teaching and educational activities. © 2019 The Authors. Ecology © 2019 The Ecological Society of Americ

    ATLANTIC BIRD TRAITS

    No full text
    Scientists have long been trying to understand why the Neotropical region holds the highest diversity of birds on Earth. Recently, there has been increased interest in morphological variation between and within species, and in how climate, topography, and anthropogenic pressures may explain and affect phenotypic variation. Because morphological data are not always available for many species at the local or regional scale, we are limited in our understanding of intra- and interspecies spatial morphological variation. Here, we present the ATLANTIC BIRD TRAITS, a data set that includes measurements of up to 44 morphological traits in 67,197 bird records from 2,790 populations distributed throughout the Atlantic forests of South America. This data set comprises information, compiled over two centuries (1820–2018), for 711 bird species, which represent 80% of all known bird diversity in the Atlantic Forest. Among the most commonly reported traits are sex (n = 65,717), age (n = 63,852), body mass (n = 58,768), flight molt presence (n = 44,941), molt presence (n = 44,847), body molt presence (n = 44,606), tail length (n = 43,005), reproductive stage (n = 42,588), bill length (n = 37,409), body length (n = 28,394), right wing length (n = 21,950), tarsus length (n = 20,342), and wing length (n = 18,071). The most frequently recorded species are Chiroxiphia caudata (n = 1,837), Turdus albicollis (n = 1,658), Trichothraupis melanops (n = 1,468), Turdus leucomelas (n = 1,436), and Basileuterus culicivorus (n = 1,384). The species recorded in the greatest number of sampling localities are Basileuterus culicivorus (n = 243), Trichothraupis melanops (n = 242), Chiroxiphia caudata (n = 210), Platyrinchus mystaceus (n = 208), and Turdus rufiventris (n = 191). ATLANTIC BIRD TRAITS (ABT) is the most comprehensive data set on measurements of bird morphological traits found in a biodiversity hotspot; it provides data for basic and applied research at multiple scales, from individual to community, and from the local to the macroecological perspectives. No copyright or proprietary restrictions are associated with the use of this data set. Please cite this data paper when the data are used in publications or teaching and educational activities. © 2019 The Authors. Ecology © 2019 The Ecological Society of Americ
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