964 resultados para Linhas eletricas


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The increased availability of soil water is important for the management of non-irrigated orange orchards. The objective of this study was to evaluate the availability of soil water in a Haplorthox (Rhodic Ferralsol) under different tillage systems used for orchard plantation, mulch management and rootstocks in a "Pera" orange orchard in northwest Parana, Brazil. An experiment in a split-split-plot design was established in 2002, in an area cultivated with Brachiaria brizantha grass in which three tillage systems (no tillage, conventional tillage and strip-tillage) were used for orchard plantation. This grass was mowed twice a year between the rows, representing two mulch managements in the split plots (no mulching and mulching in the plant rows). The split-split-plots were represented by two rootstocks ("Rangpur" lime and "Cleopatra" mandarin). The soil water content in the plant rows was evaluated in the 0-20 cm layer in 2007 and at 0-20 and 20-40 cm in 2008-2009. The effect of soil tillage systems prior to implantation of orange orchards on soil water availability was less pronounced than mulching and the rootstocks. The soil water availability was lower when "Pera" orange trees were grafted on "Cleopatra" mandarin than on "Rangpur" lime rootstocks. Mulching had a positive influence on soil water availability in the sandy surface layer (020 cm) and sandy clay loam subsurface (20-40 cm) of the soil in the spring. The production of B. brizantha between the rows and residue disposal in the plant rows as mulch increased water availability to the "Pera" orange trees.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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O objetivo deste trabalho foi caracterizar a variabilidade espacial da densidade do solo (Ds), teor de água no solo (θ) e porosidade total (Pt) em dois sistemas de manejo da colheita da cana-de-açúcar, com queima e sem queima, em um Latossolo Vermelho, na camada de 0-0,20 m. A área de estudo está localizada no município de Rio Brilhante-MS, na Usina Eldorado. A parcela de cada talhão apresentou malha com comprimento de 180 m e largura de 145,6 m, perfazendo 90 pontos distribuídos na forma de uma grade de nove colunas por dez linhas, com pontos distanciados 20 m de seu vizinho. Foram coletadas amostras de solo na camada de 0-0,20 m, nos anos agrícolas de 2007/2008 e 2008/2009. O sistema de colheita com queima apresentou maior densidade em relação ao mecanizado, nos dois períodos de análise. O teor de água no solo, assim como a porosidade, teve aumento proporcional com relação à diminuição da densidade do sistema de colheita com queima para com o mecanizado.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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A compactação do solo tem causado decréscimos na produtividade de soja, e os valores de densidade do solo a partir dos quais a produtividade decresce são pouco conhecidos. Assim, este trabalho objetivou avaliar a produtividade de soja (cv. Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) 48) em relação à densidade relativa (Dsr) de Latossolo Vermelho textura média (LVd) e argilosa (LVef). em 2001/2002, foi realizado um experimento em casa de vegetação, com amostras coletadas nos dois solos na camada de 0,0-0,2 m, peneirados a 4,0 mm, adubados e compactados em camadas de 3,0 cm, em vasos de 20 cm de altura e 25 cm de diâmetro. Foram estabelecidos quatro níveis de compactação e dois de água no solo (tensão de 0,01 e 0,05 MPa), com três repetições. A soja foi semeada em novembro (duas plantas por vaso) e irrigada duas vezes ao dia. No segundo experimento, no campo (2002/2003), utilizou-se apenas o LVd que foi compactado por meio de passadas de trator com quatro pneus de mesma largura, estabelecendo-se cinco níveis de compactação, com quatro repetições. A soja foi semeada, em dezembro de 2002, no espaçamento de 0,45 m entre linhas e 20 plantas por metro. Foram determinadas a densidade do solo (Ds) e a Ds máxima pelo teste de Proctor, sendo a Dsr obtida por divisão da Ds pela Ds máxima. Na colheita, foi avaliada a produtividade de grãos. A Dsr ótima para a produtividade de soja, em casa de vegetação, foi superior no Latossolo Vermelho eutroférrico argiloso (0,84), comparada à do Latossolo Vermelho caulinítico de textura média (0,75), na tensão de água no solo de 0,01 MPa. No campo, a Dsr ótima para soja foi de 0,80.

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The present work is grounded basically on the use of the Basic Tools for the Statistic Process Control SPC, with the intent to detect non-conformities on a given productive process. It consists on a case study accomplished at a Hemocenter in Natal (Rio Grande do Norte). In this study it is shown that, the Statistic Process Control Technique, which was used as a tool, is useful to identify on-conformities on the volume of hemocomponents. The gathering of the used data was performed by means of document analysis, direct observations and database queries. The results achieved from the study show that the analyzed products, even though when they have presented, in some cases, points out of control, they satisfied the ANVISA standards. Finally, suggestions for further improvement of the final product and guidance for future employment of CEP, also extended to other lines of production, are presented

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We have been living in a world of packed products. The package and the labels support the companies to communicate with the customers in addition to give protection, storage and convenience in proportion to the products that move in the price list. The labels mainly add up a value which helps the companies differ their products and increase the value of the brands among the final customers. However, the information given in the label are not clear sometimes. It displays a verbal-visual defective language resulted from a poor visibility, legibleness and comprehensibleness of the verbal and visual marks. The aim of this research is to verify, according to the costumers‟ view, the level of the clarity in the informative texts, harmony and ergonomic conformity of the package labels in the chocolate powder of the Claralate brand, considering the linguistic aspects presented on the labels. The criteria to evaluate the chocolate package selected were based on the linguistic field: the organization and the structure of the text derided from the classification of the textual genre; the clarity and the comprehension of the language utilized on those labels. From the ergonomic view, the informative and ergonomic conformity, based on the following requirements: legibility, symbols, characters, reading fields and intermission of the written lines. Therefore, the research done july 2007 and added july 2011 had a structured questionnaire in the interview put to the 118 customers of the chocolate package that go shopping in one of the two supermarkets in Floriano, Piauí São Jorge and/or Super Quaresma. The main results of the investigation show that the linguistic aspects in the informative texts of the labels provide the customers‟ expectancy partially, while the consideration of the informative ergonomic analyzed can contribute to the improvement of the information and consequent visual progress of those, on the labels of chocolate package investigated. As recommendation towards the maker of the product, the outcome of the research indicates: harmonize the proportion of the letters and numbers; enlarge the letters size; make the visual information more comprehensive determined by the reading field; put the expiry date in a better visual place

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O temperamento de quatro raças bovinas foi avaliado utilizando-se o teste de velocidade de fuga (FT) e o escore de comportamento (BST). FT foi definida como o tempo necessário para animais percorrerem uma distância de 2 m após a pesagem. BST foi baseada no comportamento dos animais na balança, amostrando-se quatro categorias de comportamento: movimentos, intensidade de respiração, vocalizações e coices. Os coeficientes de herdabilidade de FT e BST foram estimados com uso de um modelo de máxima verossimilhança restrita, considerando meio irmãos paternos. Caracu apresentou menores médias para BST do que as demais raças. Nelore apresentou resultados intermediários, seguida por Guzerat e Gyr com médias mais elevadas (p < 0,05). Resultados similares foram observados para FT, mas as médias de Caracu e Nelore não diferiram entre si. Observou-se baixa associação entre FT e BST (r p= -0,36; p < 0,01). A correlação entre rank de touros ordenados pelos seus valores preditos (p) para FT e BST foi moderada e negativa (r s = -0,63; p < 0,001). A herdabilidade de FT e BST foi de 0,35 e 0,34, respectivamente. A comparação de rebanhos Nelore com diferentes critérios de seleção para peso corporal mostrou que linhas de seleção podem modular positivamente o temperamento de Bos indicus.

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Technological innovation promotes the generation of economic value by creating a new product, process or organizational management model, being classified as dynamic and multidimensional. Government intervention has the role of acting through government grant programs to foster the integration of innovative processes in small companies, due to the high costs and risks of development, strengthening the country`s economy in this phase. The distribution of this grant is determined by criteria, based especially in subjective judgments, which are based on the beliefs and perceptions about the technological opportunities and market actors involved in the process, being very difficult to measure the probability of success of the project under evaluation. This study aims to identify the most relevant selection criteria that must be inserted in grants programs at Rio Grande do Norte executed by Fundação de Pesquisa do Rio Grande do Norte (FAPERN). Initially, there was a systematization of 18 countries, covering 41 programs in foreign countries and 29 in Brazil. Based on the data collected, we conducted one survey containing four programs of FAPERN (INOVA I, INOVA II , INOVA III and INOVA IV), covering 44 companies and analyzing their responses according to the Likert scale , obtaining the degree of importance given by the respondent to each of the criteria in the questionnaire . As a result, drew up a proposal for new criteria to be used in the next FAPERN´s grants, containing 13 new criteria. It is expected, therefore, to contribute to a better spending of public funds invested in companies subsidized in Brazil

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This research aims at to contribute to show the consolidation of the area of Information Systems (IS) as area of knowledge in Production Engineering. For this, it according to presents a scenery of the publication in IS in the field of the Production Engineering in Brazil amount of articles, the authorship profile, the methodologies, the citations, the research thematic and the continuity of the research thematic. The base for this study was the works published in the National Meeting of Production Engineering - ENEGEP of years 2000, 2001, 2002, 2003 and 2004, inside of the area of Information Systems. Classified as bibliographical research, of applied nature, quantitative boarding, of the point of view of the objectives description-exploration was called and for the collection of data its comment was systematic with bibliographical survey. As field research, the method of collection of data if constituted of the elaboration of an analysis protocol and, to arrive itself at the final diagnosis, it operation the data through the statistical method, with the accomplishment of descriptive analyses. It approached concepts of IS and the seek areas and, it studied research correlate in Production Engineering, in Information Systems, in Information Science and other areas of the knowledge. How much to the results one concluded that the national and international contents are compatible and that the area of IS is in constant evolution. For the continuity of research lines it was observed that the majority of the authors was faithful to the area of Systems of Information. Amongst other found results, some institutions must try to increase its volume of publications and research, while others must look for to keep its reached mark already in the last years

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This thesis carries through an application of Analysis of Multicriterion Decision with use of the method of Analytical Hierarchy Process (AHP) in the problematic one of taking of decision of the adoption of electronic collecting in the system of urban transport in the country, a subject that has been controversial. A modeling of criteria and alternatives is carried through and applied a questionnaire based on method AHP the excellent actors in the system of urban transport - Leading of the Managing Agency Public Municipal theatre of Urban Transports, Controller of Company of Bus, Controller of Labor union, Controller of Union of Companies, Communitarian Leader. The considered alternatives were: the maintenance of the current state with collectors, the implementation of electronic collection without collectors, and the implementation of electronic collection with collectors. The used criteria were: job, impact in the fare, control of the system, easiness of use, information. The study was carried through in the city of Natal, RN, where if the adoption of electronic collection argues and where this implementation in some bus lines between Natal and Parnamirim exists, city that integrates the region of the great Natal. The main results of the method evidence in a dimension, the viability of use of method AHP with questionnaire by means of validation of the judgments with analysis of variance beyond proper the normal mechanisms of analysis of consistency to the method, and in another one, the contribution of the analysis boarding multicriterion to become the judgments more clearly. The main results of the analysis help to show that although to models of criteria and distinct judgments of the actors, the method evidenced that it has inclination the adoption of the electronic collection on the current situation, even so with divergences between the maintenance or not of the collector. The research points to the possibility of accomplishment of the application of the AHP in successive rounds of judgments

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The usual programs for load flow calculation were in general developped aiming the simulation of electric energy transmission, subtransmission and distribution systems. However, the mathematical methods and algorithms used by the formulations were based, in majority, just on the characteristics of the transmittion systems, which were the main concern focus of engineers and researchers. Though, the physical characteristics of these systems are quite different from the distribution ones. In the transmission systems, the voltage levels are high and the lines are generally very long. These aspects contribute the capacitive and inductive effects that appear in the system to have a considerable influence in the values of the interest quantities, reason why they should be taken into consideration. Still in the transmission systems, the loads have a macro nature, as for example, cities, neiborhoods, or big industries. These loads are, generally, practically balanced, what reduces the necessity of utilization of three-phase methodology for the load flow calculation. Distribution systems, on the other hand, present different characteristics: the voltage levels are small in comparison to the transmission ones. This almost annul the capacitive effects of the lines. The loads are, in this case, transformers, in whose secondaries are connected small consumers, in a sort of times, mono-phase ones, so that the probability of finding an unbalanced circuit is high. This way, the utilization of three-phase methodologies assumes an important dimension. Besides, equipments like voltage regulators, that use simultaneously the concepts of phase and line voltage in their functioning, need a three-phase methodology, in order to allow the simulation of their real behavior. For the exposed reasons, initially was developped, in the scope of this work, a method for three-phase load flow calculation in order to simulate the steady-state behaviour of distribution systems. Aiming to achieve this goal, the Power Summation Algorithm was used, as a base for developing the three phase method. This algorithm was already widely tested and approved by researchers and engineers in the simulation of radial electric energy distribution systems, mainly for single-phase representation. By our formulation, lines are modeled in three-phase circuits, considering the magnetic coupling between the phases; but the earth effect is considered through the Carson reduction. It s important to point out that, in spite of the loads being normally connected to the transformer s secondaries, was considered the hypothesis of existence of star or delta loads connected to the primary circuit. To perform the simulation of voltage regulators, a new model was utilized, allowing the simulation of various types of configurations, according to their real functioning. Finally, was considered the possibility of representation of switches with current measuring in various points of the feeder. The loads are adjusted during the iteractive process, in order to match the current in each switch, converging to the measured value specified by the input data. In a second stage of the work, sensibility parameters were derived taking as base the described load flow, with the objective of suporting further optimization processes. This parameters are found by calculating of the partial derivatives of a variable in respect to another, in general, voltages, losses and reactive powers. After describing the calculation of the sensibility parameters, the Gradient Method was presented, using these parameters to optimize an objective function, that will be defined for each type of study. The first one refers to the reduction of technical losses in a medium voltage feeder, through the installation of capacitor banks; the second one refers to the problem of correction of voltage profile, through the instalation of capacitor banks or voltage regulators. In case of the losses reduction will be considered, as objective function, the sum of the losses in all the parts of the system. To the correction of the voltage profile, the objective function will be the sum of the square voltage deviations in each node, in respect to the rated voltage. In the end of the work, results of application of the described methods in some feeders are presented, aiming to give insight about their performance and acuity

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The goal of this work is to propose a SLAM (Simultaneous Localization and Mapping) solution based on Extended Kalman Filter (EKF) in order to make possible a robot navigates along the environment using information from odometry and pre-existing lines on the floor. Initially, a segmentation step is necessary to classify parts of the image in floor or non floor . Then the image processing identifies floor lines and the parameters of these lines are mapped to world using a homography matrix. Finally, the identified lines are used in SLAM as landmarks in order to build a feature map. In parallel, using the corrected robot pose, the uncertainty about the pose and also the part non floor of the image, it is possible to build an occupancy grid map and generate a metric map with the obstacle s description. A greater autonomy for the robot is attained by using the two types of obtained map (the metric map and the features map). Thus, it is possible to run path planning tasks in parallel with localization and mapping. Practical results are presented to validate the proposal

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Eventually, violations of voltage limits at buses or admissible loadings of transmission lines and/or power transformers may occur by the power system operation. If violations are detected in the supervision process, corrective measures may be carried out in order to eliminate them or to reduce their intensity. Loading restriction is an extreme solution and should only be adopted as the last control action. Previous researches have shown that it is possible to control constraints in electrical systems by changing the network topology, using the technique named Corrective Switching, which requires no additional costs. In previous works, the proposed calculations for verifying the ability of a switching variant in eliminating an overload in a specific branch were based on network reduction or heuristic analysis. The purpose of this work is to develop analytical derivation of linear equations to estimate current changes in a specific branch (due to switching measures) by means of few calculations. For bus-bar coupling, derivations will be based on short-circuit theory and Relief Function methodology. For bus-bar splitting, a Relief Function will be derived based on a technique of equivalent circuit. Although systems of linear equations are used to substantiate deductions, its formal solution for each variant, in real time does not become necessary. A priority list of promising variants is then assigned for final check by an exact load flow calculation and a transient analysis using ATP Alternative Transient Program. At last, results obtained by simulation in networks with different features will be presented

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Neste trabalho, são utilizadas a Técnica da Ressonância Transversa (TRT) e a Técnica da Ressonância Transversa Modificada (MTRT), para a determinação das freqüências dos modos ressonantes de antenas de microfita com patch quadrado, retangular e circular e com substratos isotrópicos e anisotrópicos. Para isso, é proposto um modelo da cavidade equivalente, onde a antena tipo patch retangular é representada como sendo a superposição de duas linhas infinitas em microfita, uma de largura W, representando a dimensão que expressa a largura do patch, e a outra com largura L, representando a dimensão que expressa o comprimento do patch. A avaliação da eficiência e aplicabilidade dos métodos citados é realizada comparando-se com resultados experimentais e obtidos através de outras técnicas. Três situações serão verificadas: estruturas com substrato infinito, estrutura com substrato tipo pedestal e estruturas com substrato truncado além dos limites da fita metálica. Os resultados obtidos demonstram que as técnicas de análise de onda completa utilizadas neste trabalho, por um formalismo matemático mais rigoroso, são eficientes e precisas tanto na aplicação em estruturas com substrato isotrópico como nas que possuem substrato anisotrópico. Inicialmente são consideradas apenas as estruturas com substratos isotrópicos, com diferentes constantes dielétricas, e é avaliada a influência da largura do substrato sobre as freqüências dos modos ressonantes das antenas. Posteriormente, a análise do truncamento do dielétrico é realizada para estruturas com substrato anisotrópico. Em todos os casos, os resultados experimentais, obtidos a partir da construção de protótipos, são confrontados com os obtidos a partir de simulação, utilizando as técnicas TRT e MTRT. No final, as técnicas descritas são utilizadas para antenas tipo patch circular, sendo utilizada uma técnica de equivalência para transformar a antena circular em outra quadrada ou retangular equivalente, dependendo do modo que se queira encontrar. Os resultados obtidos são então analisados, observando-se uma boa concordância e indicando a viabilidade do método. Após isso, são apresentadas as conclusões e sugeridos alguns temas para a continuidade deste trabalho