981 resultados para Mezcla (Dinámica de fluidos)
Resumo:
The introduction of new cotton cultivars in the Midwest region of Brazil resulted in a significant increase in productivity, but the use of inappropriate farming techniques brought many problems to field, as the higher incidence of pests, diseases and weeds. The aim of this work was to study the population dynamics of eggs and larvae of cotton leafworm and natural egg parasitism of the pest by Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) at different phenological stages of conventional and transgenic cultivars (Bollgard I) of cotton was carried out this experiment from December 2007 to April 2008 in Ipameri, Goias State, Brazil. The experimental design was a randomized blocks with five trataments and four replications. The treatments consisting of the conventional cotton cultivars DeltaOPAL, FMX 966, FMX 993, FMX 910 and the cultivar transgenic NuOPAL. Allabama argillacea Hubner (Lepidoptera: Noctuidae) oviposited on all cultivars, not presented differences in relation to oviposition preference. Compared to the average number of eggs of A. argillacea parasitized by T. pretiosum, there were no differences between cultivars. In conventional cultivars, small, medium and large larvae occurred from 34 days after plant emergence until the end of the cycle, while in the transgenic cultivar were found only small caterpillars. Cultivar NuOPAL control cotton leafworm since the first larval stage, and does not interfere in egg parasitism by T. pretiosum compared with other cultivars.
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
This work is a case study to investigate the dynamics of the historians thought as they produce a knowledge about the history of the area measurement systems as forms of historical expressions and representations. We refer to some of the ideas of David Bohm (1989, 1992, 1994, 1996) to support our theoretical understanding about the operation of thought. We chose a period that is recognized by the theorists as the origin of the geometrical thought -embracing the knowledge developed by the Egyptians, Babylonians, Chinese, Hindus, Greeks and Romans- and is referred to as containing a cycle in the development of this knowledge, described as beginning, apogee and decline. We assume this history, as told by the theorists, as a version that we organize and tell with the help of three sets of categories. The first refers to the elements that take part in the measurement practices; the second refers to the historians understanding about the development of the scientific knowledge. This exercise allowed us to extract the theorists main beliefs, that we criticized in the light of the knowledge about Cubação (Dal Pian, 1990). We stress the importance of the methodological approach adopted in this study to the teaching of Geometry and its history
Resumo:
This project was based on an implemented investigation of the institutional self-evaluation at Municipal Emmanuel Bezerra school, located at the west zone of Natal capital in Rio Grande do Norte state, where school individuals were analysed in interaction. A qualitative research was taken under the use of several pieces of information and collected out of several sources, such as: managing, docent and administrative staff interviews; present school legislation, political pedagogical project, scholar regiment as well as the 2013 action plans documental analyses; and the literature review focused in books and articles which treats of evaluation, State Evaluator and the public educational politics in order to promote the dialogue between school theory and reality. The institutional evaluation has been the theme debated through several studies. However, with its major focus on the evaluation systems and High Education aiming to raise competition having implying the reaching of educational quality as justification under liberal view. Notwithstanding, over the controlling function of the educational results and competition trigger amongst the educational institutions to the accruement of the received resources, it is believed that this institutional evaluation, however the system, can assist in the educational services improvement offered to the local public, when endeavoured to the purpose of supporting human development. Having the obtained data, the self-evaluation process implemented at the concerned school, the conceptions which permeate the school environment as well as the community joining given in this object lesson, was described and analysed as dialoguing with the political pedagogical project and comprehending the constitution in a democratic management
Resumo:
Objetivou-se avaliar o efeito de diferentes relações entre proteína verdadeira e nitrogênio não-proteico sobre o consumo e a dinâmica de trânsito e degradação ruminal da fibra em detergente neutro (FDN) da forragem em bovinos em pastejo durante o período das águas. Foram utilizados cinco novilhos mestiços Holandês × Zebu, castrados, com peso corporal inicial de 335±35 kg fistulados no rúmen e no abomaso. Os tratamentos foram: controle (somente pasto); e suplementos com ureia; com 2/3 de compostos nitrogenados oriundos da ureia e 1/3 de compostos nitrogenados oriundos da albumina; com 1/3 de compostos nitrogenados oriundos da ureia e 2/3 de compostos nitrogenados oriundos da albumina; e com albumina. Foram fornecidos 200 g/dia de proteína bruta (PB) a partir dos suplementos. O experimento foi conduzido segundo delineamento em quadrado latino 5 × 5, com cinco períodos experimentais de 15 dias. Não foram observados efeitos da suplementação sobre o consumo voluntário, com exceção do consumo de PB, que aumentou com a suplementação. A substituição da ureia por albumina nos suplementos teve efeito linear sobre o consumo de PB. Os consumos dos demais componentes da dieta não foram afetados pela composição dos suplementos. Nenhum efeito foi observado sobre a taxa de passagem ruminal de compostos fibrosos. O fornecimento de suplementos ampliou, em média, a estimativa da taxa comum de latência e degradação da FDN. Contudo, não houve efeito da alteração na composição dos suplementos sobre este parâmetro. A suplementação de bovinos com fontes de compostos nitrogenados degradáveis no rúmen proteicos ou não-proteicos durante o período das águas não afeta o consumo voluntário de pasto.
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
The importance of the airport sector in the development of a country refers to the need for studies on management of airports, to aid the process of decision making. In Brazil, growth in passenger demand is why investments in order to balance the capacity of an airport with air demand. Thus, the study aims to develop a model for Dynamic Systems able to assist airport management in Brazilian sizing subsystems an airport (Passenger Terminal, Runway and Patio). The methodology of this work consists in the steps of defining the problem, formulating the hypothesis dynamic building simulation model, and validation experiments. Finally, we examined the status of each subsystem in thirteen Brazilian airports in scenarios current, most likely and optimistic for air passenger demand
Resumo:
O fósforo (P) é um importante nutriente para o surgimento de brotos em alfafa. Através do estudo da dinâmica do aparecimento de brotos pode-se obter informações que auxiliam na adoção de um manejo eficiente. Diversas fontes de P estão disponíveis no mercado, sendo que a eficiência deste nutriente é afetada pela acidez do solo. O uso do gesso com fosfato de rocha pode corrigir o perfil do solo em relação ao alumínio e diminuir a fixação de P. Num experimento conduzido em vasos, superfosfato triplo (ST), fosfato de Gafsa (FG) e FG com gesso, aplicados antes e depois da calagem, foram avaliados para se estudar o número de brotos laterais e basais em alfafa, assim como a dinâmica do surgimento destes brotos em função das seguintes doses: 0, 50, 100 e 200 mg P dm-3. A avaliação envolveu três cortes da cultura. A dose de 100 mg P dm-3 retardou em 6 a 15 dias o surgimento do segundo broto basal quando comparada à dose de 200 mg P dm-3. Os brotos laterais surgiram 24 dias após o aparecimento dos brotos basais quando empregou-se a dose de 200 mg P dm-3. A adição de fósforo aumentou o número de brotos basais e laterais de 1,5 e 0,5 broto/planta para 8,0 e 6,9 brotos/planta, respectivamente. Verificou-se um maior número de hastes basais com a utilização do FG (5,1 brotos/planta) do que com o uso de ST (2,9 brotos/planta). Não houve efeito do gesso sobre os brotos laterais. O uso do FG mais gesso resultou em 5,9 brotos basais/planta, enquanto que o uso do FG não combinado com gesso resultou em 3,9 brotos basais/planta. Não houve efeito do momento de calagem sobre o número de brotos da alfafa.
Resumo:
The industrial automation is directly linked to the development of information tecnology. Better hardware solutions, as well as improvements in software development methodologies make possible the rapid growth of the productive process control. In this thesis, we propose an architecture that will allow the joining of two technologies in hardware (industrial network) and software field (multiagent systems). The objective of this proposal is to join those technologies in a multiagent architecture to allow control strategies implementations in to field devices. With this, we intend develop an agents architecture to detect and solve problems which may occur in the industrial network environment. Our work ally machine learning with industrial context, become proposed multiagent architecture adaptable to unfamiliar or unexpected production environment. We used neural networks and presented an allocation strategies of these networks in industrial network field devices. With this we intend to improve decision support at plant level and allow operations human intervention independent
Resumo:
Artificial Intelligence techniques are applied to improve performance of a simulated oil distillation system. The chosen system was a debutanizer column. At this process, the feed, which comes to the column, is segmented by heating. The lightest components become steams, by forming the LPG (Liquefied Petroleum Gas). The others components, C5+, continue liquid. In the composition of the LPG, ideally, we have only propane and butanes, but, in practice, there are contaminants, for example, pentanes. The objective of this work is to control pentane amount in LPG, by means of intelligent set points (SP s) determination for PID controllers that are present in original instrumentation (regulatory control) of the column. A fuzzy system will be responsible for adjusting the SP's, driven by the comparison between the molar fraction of the pentane present in the output of the plant (LPG) and the desired amount. However, the molar fraction of pentane is difficult to measure on-line, due to constraints such as: long intervals of measurement, high reliability and low cost. Therefore, an inference system was used, based on a multilayer neural network, to infer the pentane molar fraction through secondary variables of the column. Finally, the results shown that the proposed control system were able to control the value of pentane molar fraction under different operational situations
Resumo:
Several research lines show that sleep favors memory consolidation and learning. It has been proposed that the cognitive role of sleep is derived from a global scaling of synaptic weights, able to homeostatically restore the ability to learn new things, erasing memories overnight. This phenomenon is typical of slow-wave sleep (SWS) and characterized by non-Hebbian mechanisms, i.e., mechanisms independent of synchronous neuronal activity. Another view holds that sleep also triggers the specific enhancement of synaptic connections, carrying out the embossing of certain mnemonic traces within a lattice of synaptic weights rescaled each night. Such an embossing is understood as the combination of Hebbian and non-Hebbian mechanisms, capable of increasing and decreasing respectively the synaptic weights in complementary circuits, leading to selective memory improvement and a restructuring of synaptic configuration (SC) that can be crucial for the generation of new behaviors ( insights ). The empirical findings indicate that initiation of Hebbian plasticity during sleep occurs in the transition of the SWS to the stage of rapid eye movement (REM), possibly due to the significant differences between the firing rates regimes of the stages and the up-regulation of factors involved in longterm synaptic plasticity. In this study the theories of homeostasis and embossing were compared using an artificial neural network (ANN) fed with action potentials recorded in the hippocampus of rats during the sleep-wake cycle. In the simulation in which the ANN did not apply the long-term plasticity mechanisms during sleep (SWS-transition REM), the synaptic weights distribution was re-scaled inexorably, for its mean value proportional to the input firing rate, erasing the synaptic weights pattern that had been established initially. In contrast, when the long-term plasticity is modeled during the transition SWSREM, an increase of synaptic weights were observed in the range of initial/low values, redistributing effectively the weights in a way to reinforce a subset of synapses over time. The results suggest that a positive regulation coming from the long-term plasticity can completely change the role of sleep: its absence leads to forgetting; its presence leads to a positive mnemonic change
Resumo:
ln this work the implementation of the SOM (Self Organizing Maps) algorithm or Kohonen neural network is presented in the form of hierarchical structures, applied to the compression of images. The main objective of this approach is to develop an Hierarchical SOM algorithm with static structure and another one with dynamic structure to generate codebooks (books of codes) in the process of the image Vector Quantization (VQ), reducing the time of processing and obtaining a good rate of compression of images with a minimum degradation of the quality in relation to the original image. Both self-organizing neural networks developed here, were denominated HSOM, for static case, and DHSOM, for the dynamic case. ln the first form, the hierarchical structure is previously defined and in the later this structure grows in an automatic way in agreement with heuristic rules that explore the data of the training group without use of external parameters. For the network, the heuristic mIes determine the dynamics of growth, the pruning of ramifications criteria, the flexibility and the size of children maps. The LBO (Linde-Buzo-Oray) algorithm or K-means, one ofthe more used algorithms to develop codebook for Vector Quantization, was used together with the algorithm of Kohonen in its basic form, that is, not hierarchical, as a reference to compare the performance of the algorithms here proposed. A performance analysis between the two hierarchical structures is also accomplished in this work. The efficiency of the proposed processing is verified by the reduction in the complexity computational compared to the traditional algorithms, as well as, through the quantitative analysis of the images reconstructed in function of the parameters: (PSNR) peak signal-to-noise ratio and (MSE) medium squared error
Resumo:
Apesar da importância na dinâmica dos ecossistemas aquáticos, as macrófitas podem formar densas e extensas colonizações em corpos hídricos cujos equilíbrios ecológicos foram rompidos. Nessas condições, essas plantas promovem uma série de problemas que as tornam alvos de controle. Para elaboração de planos adequados de manejo dessa vegetação, é fundamental o conhecimento das dinâmicas relativas das populações que a compõem. O objetivo deste trabalho foi realizar levantamentos mensais da composição específica da comunidade de macrófitas que coloniza o reservatório de Santana, localizado no município de Piraí/RJ, monitorando 97 pontos georreferenciados, abrangendo toda a lâmina d'água. Foram identificadas 41 espécies, inseridas em 21 famílias botânicas. As famílias Poaceae, Pontederiaceae e Cyperacae foram as que apresentaram os maiores números de espécies ao longo do ano. Salvinia herzogii e Egeria densa apresentaram as maiores notas anuais de colonização do reservatório. As populações de Eichhornia azurea, Brachiaria arrecta e Paspalum repens completaram o grupo das espécies numericamente mais relevantes. As plantas de hábito flutuante tenderam a apresentar populações com padrão de distribuição geográfica casualizado, enquanto as espécies fixadas no sedimento e as submersas apresentaram populações com padrão agregado. Não houve expressivas variações mensais dos valores dos índices de diversidade (H') e de equitabilidade (E') das comunidades de macrófitas aquáticas ao longo do ano. O dendrograma construído com o coeficiente de Odum mostrou uma seqüência lógica dos meses, evidenciando uma definida sucessão de populações divididas em dois grupos de similaridade separados pelo mês de junho. Nessa época, o nível de água do reservatório foi reduzido e o sedimento ficou exposto, favorecendo as espécies de hábito emergente.
Resumo:
O tebuthiuron é um herbicida residual amplamente utilizado em cana-de-açúcar cultivada no sistema tradicional. em áreas de cana-crua, o comportamento desse herbicida na palha deixada sobre o solo não é muito conhecido. Para melhor entender esse comportamento, avaliou-se neste trabalho a dinâmica do tebuthiuron aplicado sobre a palha de cana-de-açúcar em diferentes períodos e intensidades de chuvas após a aplicação. Foram conduzidos quatro experimentos instalados em delineamento experimental inteiramente casualizado, com quatro repetições. No primeiro, avaliou-se a interceptação do herbicida tebuthiuron no momento da aplicação sobre 0, 1, 2, 4, 6, 8, 10, 15 e 20 t ha-1 de palha de cana-de-açúcar. No segundo, foi avaliada a passagem do herbicida em 5, 10 e 15 t ha-1 de palha, simulando-se o equivalente a 2,5, 5, 10, 15, 20, 35, 50 e 65 mm de chuva, um dia após a aplicação (DAA). No terceiro, estudou-se o efeito de diferentes períodos de permanência (0, 1, 7, 14 e 28 DAA) do tebuthiuron na palha (10 t ha-1) antes da aplicação das mesmas precipitações simuladas no segundo estudo, acrescentando-se ainda mais uma simulação de 20 mm aos 7 e aos 14 dias após a aplicação do herbicida e das lâminas acumuladas de 65 mm. No quarto, avaliou-se a transposição do herbicida aplicado a 10 t ha-1 de palha, recebendo posteriormente uma lâmina de chuva de água de 20 mm e, no outro tratamento, uma irrigação de vinhaça de 20 mm, um dia após a aplicação. A quantificação do tebuthiuron foi realizada por cromatografia líquida de alta eficiência (CLAE). Nos estudos de dinâmica observou-se que, quanto maior a quantidade de palha, menor é a quantidade de produto que a transpõe no momento da aplicação. No segundo ensaio, pôde-se observar que, quanto maior a quantidade de palha, menor é a quantidade total extraída na simulação da precipitação. Para o terceiro estudo, os resultados indicaram que, quanto maior o tempo que o produto permanece na palha antes da ocorrência de chuva, menor é a extração total do produto com 65 mm de precipitação. Para as chuvas de 20 mm aos 7 e 14 dias após aplicação do herbicida e da lâmina de 65 mm para cada período, no terceiro ensaio, observou-se extração de quantidades mínimas do herbicida. A utilização de vinhaça como chuva simulada proporcionou aumento de 17% do tebuthiuron lixiviado, quando comparado com a mesma quantidade de chuva simulada com água.