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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
331

Simulador de redes Profibus / Profibus network simulator

Torres, Renato da Veiga 19 September 2013 (has links)
Este trabalho propõe o desenvolvimento de um simulador de redes Profibus DP que reproduz o comportamento de uma rede real. A simulação de redes em condições de falha permite aos usuários experimental situações que podem ocorrer em instalações reais, facilitando o treinamento de manutenção e antecipando ações corretivas. O simulador permite o treinamento de usuários que utilizam ferramentas de diagnóstico. Auxilia no estudo do protocolo Profibus DP e também contribui com o desenvolvimento da ferramenta Profidoctor que é um sistema especialista com o objetivo de fazer a análise de problemas de rede. / This work aims development of Profibus DP network simulator that reproduces real network behavior. The network simulation under fault conditions allows experiment situations that may occur in real network installations, helping in maintenance training and corrective actions. This simulator tool helps in diagnostic tool users training, Profibus DP protocol learning and also assists development of new tool Profidoctor: an expert system that will report complete analysis of network problems.
332

"Desenvolvimento de um Simulador de Treinamento para Operadores do Reator de Pesquisa IEA-R1" / DEVELOPMENT OF A TRAINING SIMULATOR TO OPERATORS OF THE IEA-R1 RESEARCH REACTOR

Ricardo Pinto de Carvalho 02 August 2006 (has links)
Este trabalho apresenta o desenvolvimento de um Simulador do Reator de Pesquisa IEAR1. O Simulador foi desenvolvido com Visual C++ em duas etapas: 1) construção dos modelos matemáticos e 2) criação e configuração de interfaces gráficas em um aplicativo Windows XP. Utilizou-se uma modelagem simplificada dos principais fenômenos físicos: o nuclear através de cinética pontual, e o modelo de térmica e hidráulica através das leis de conservação de massa e energia no canal médio do reator. As equações diferenciais dinâmicas dos processos nucleares, térmicos e hidráulicos foram solucionadas pela técnica de diferenças finitas através do método de Runge-Kutta de 4ª ordem. Foram modelados os sistemas: controle de reatividade, resfriamento do reator e proteção do reator. As variáveis de processo são armazenadas em arquivos ASCII. O Simulador permite o usuário navegar por interfaces gráficas dos sistemas e monitorar tendências dos transientes de operação sendo uma ferramenta interativa para ensino e treinamento de operadores do IEA-R1. Este também pode ser usado por alunos e professores no ensino de teoria de reatores, térmica e hidráulica. O Simulador permite simulações de operações de partida, manobra de potência e parada. / This work reports the development of a Simulator for the IEA-R1 Research Reactor. The Simulator was developed with Visual C++ in two stages: 1) construction of the mathematics models and 2) development and configuration of graphics interfaces in a Windows XP executable. A simplified modeling was used for main physics phenomena, using a point kinetics model for the nuclear process and the energy and mass conservation laws in the average channel of the reactor for the thermal hydraulic process. The dynamics differential equations were solved by using finite differences through the 4th order Runge- Kutta method. The reactivity control, reactor cooling, and reactor protection systems were also modeled. The process variables are stored in ASCII files. The Simulator allows navigating by screens of the systems and monitoring tendencies of the operational transients, being an interactive tool for teaching and training of IEA-R1 operators. It also can be used by students, professors, and researchers in teaching activities in reactor and thermal hydraulics theory. The Simulator allows simulations of operations of start up, power maneuver, and shut down.
333

Programa computacional para um simulador de vôo / A computer program for a flight simulator

Beluzo, Carlos Eduardo 27 April 2006 (has links)
Os simuladores de vôo têm sido uma importante ferramenta para treinamento de pilotos e análise de vôo sem ter que se desembolsar grandes quantias monetárias, economizando combustível e evitando acidentes. Conseqüentemente, a demanda por simuladores de vôo tem aumentado tanto na indústria quanto na pesquisa. Com o intuito de futuramente construir um simulador de vôo, foi desenvolvido um projeto para elaboração de um software capaz de simular uma aeronave em vôo, do ponto de vista de dinâmica de vôo. O software SIMAERO foi desenvolvido na linguagem de programação C++ e simula a dinâmica de vôo de uma aeronave. Esta simulação consiste em resolver as equações de movimento da aeronave, utilizando o modelo matemático de equações diferenciais ordinárias proposto por ETKIN & REID, et al (1996). O modelo matemático é solucionado através do método de integração numérica Runge-Kutta de 4ª ordem conforme apresentado em CONTE (1977). Como parâmetros de entrada são informadas as seguintes características da aeronave: dados geométricos, dados aerodinâmicos e derivadas de estabilidade. Os resultados das simulações são apresentados em gráficos cartesianos e gravados em arquivos. Os gráficos são úteis para que possa ser feita uma posterior análise do comportamento da aeronave. Os arquivos gravados com os resultados das simulações podem ser utilizados em alguma aplicação futura, como sinas de entrada para uma plataforma de simulação, por exemplo. Neste trabalho será descrito como o SIMAERO foi desenvolvido e ao final serão apresentados alguns resultados obtidos. / Flight simulators have been an important tool for pilots training and for flight analyses, without having to spend a high quantity of money, saving gas and prevent accidents. Because of this, the demand for flight simulators has increased both in industry and in research centers. With the objective of in future build a flight simulator, a project to develop a software that is able to simulate the dynamics of flight of a flying aircraft was developed. The SIMAERO software was developed using C++ and its principal functionality is to simulate the dynamics of flight of an aircraft. This simulation basically is the solution of the system of motion equations of the aircraft, using the mathematical model described by ETKIN & REID, et al (1996). The mathematical model is solved using the 4th order Runge-Kutta numeric integration method, as presented in CONTE (1977). For the simulation, the geometric data, the aerodynamic data, and the dimensional derivates are passed to the software as input arguments. The results of the simulations are displayed as cartesians graphics and recorded as data files. The graphics are useful for visual analyses of the aircraft behavior, and the file, with the results of the simulation, can be used as input data for ground based simulator, for example. In this work, the development of the software SIMAERO will be presented, and then some results of the simulation of one aircraft will be shown.
334

The Dynamics of ISIS: An Emerging-State Actor

Clancy, Timothy 14 April 2016 (has links)
This paper explains how the Islamic State grew rapidly, answering a question of "what is" the Islamic State? A review of existing literature on simulation modeling of insurgencies identifies several gaps, as existing theories of non-state actors and insurgencies are inadequate to explain ISIS's performance. Additionally, there are few mathematical simulation models of insurgent behavior that can reproduce ISIS results. Finally, what models exist are not detailed enough either to conduct detailed experiments testing proposed explanations of ISIS, or evaluate policy responses aimed at containing or mitigating ISIS. The paper offers several contributions. First it proposes a dynamic hypothesis that the Islamic State (ISIS) is an emerging-state actor, a new form of actor that differs from traditional non- state actors and insurgencies. Propositions are constructed and presented as an overall theory of emerging-state actor behavior. These propositions are then simulated as experiments within a detailed model parameterized with conditions very similar to what ISIS faced in Iraq and Syria 2013. The model is then run from 2013-2020, and experiment results confirm evidence of emerging- state actor behavior and allow refinement of model boundary assumptions. Second, an initial set of intervention policies are tested in a variety of conditions: best case, operationally constrained, isolated, combined, and at different timing intervals. Analysis of the results yields key dynamic insights. These insights aid policy makers in understanding the challenges posed by emerging state actors. Finally, the detailed simulation model used to test the propositions and policy analysis, including a novel approach to combat simulation with endogenous geospatial feedback, is provided in full detail in two Appendices. Appendix A provides a sector-by-sector view of model structure and equations. Appendix B provides more discussion, analysis and sources used to develop model structure, establish parameter values and determine equations for the simulation. Due to length and other considerations, Appendix B is available only upon request. The detailed simulation model can be used to refine non-state actor theories (configured for insurgencies, emerging-state actors, or other scenarios). The model can be loaded with other scenarios to simulate other actors in other geospatial terrain: ISIS in Libya, Boko Haram in Nigeria, the returning Taliban in Afghanistan, etc. Keywords: ISIS, ISIL, DAESH, insurgency, conflict, security, stability, non-state actor, emerging- state actor, combat simulator, geospatial, national security.
335

The Dynamics of ISIS: An Emerging-State Actor

Clancy, Timothy 14 April 2016 (has links)
This paper explains how the Islamic State grew rapidly, answering a question of "what is" the Islamic State? A review of existing literature on simulation modeling of insurgencies identifies several gaps, as existing theories of non-state actors and insurgencies are inadequate to explain ISIS's performance. Additionally, there are few mathematical simulation models of insurgent behavior that can reproduce ISIS results. Finally, what models exist are not detailed enough either to conduct detailed experiments testing proposed explanations of ISIS, or evaluate policy responses aimed at containing or mitigating ISIS. The paper offers several contributions. First it proposes a dynamic hypothesis that the Islamic State (ISIS) is an emerging-state actor, a new form of actor that differs from traditional non- state actors and insurgencies. Propositions are constructed and presented as an overall theory of emerging-state actor behavior. These propositions are then simulated as experiments within a detailed model parameterized with conditions very similar to what ISIS faced in Iraq and Syria 2013. The model is then run from 2013-2020, and experiment results confirm evidence of emerging- state actor behavior and allow refinement of model boundary assumptions. Second, an initial set of intervention policies are tested in a variety of conditions: best case, operationally constrained, isolated, combined, and at different timing intervals. Analysis of the results yields key dynamic insights. These insights aid policy makers in understanding the challenges posed by emerging state actors. Finally, the detailed simulation model used to test the propositions and policy analysis, including a novel approach to combat simulation with endogenous geospatial feedback, is provided in full detail in two Appendices. Appendix A provides a sector-by-sector view of model structure and equations. Appendix B provides more discussion, analysis and sources used to develop model structure, establish parameter values and determine equations for the simulation. Due to length and other considerations, Appendix B is available only upon request. The detailed simulation model can be used to refine non-state actor theories (configured for insurgencies, emerging-state actors, or other scenarios). The model can be loaded with other scenarios to simulate other actors in other geospatial terrain: ISIS in Libya, Boko Haram in Nigeria, the returning Taliban in Afghanistan, etc. Keywords: ISIS, ISIL, DAESH, insurgency, conflict, security, stability, non-state actor, emerging- state actor, combat simulator, geospatial, national security.
336

Applications of information sharing for code generation in process virtual machines

Kyle, Stephen Christopher January 2016 (has links)
As the backbone of many computing environments today, it is important that process virtual machines be both performant and robust in mobile, personal desktop, and enterprise applications. This thesis focusses on code generation within these virtual machines, particularly addressing situations where redundant work is being performed. The goal is to exploit information sharing in order to improve the performance and robustness of virtual machines that are accelerated by native code generation. First, the thesis investigates the potential to share generated code between multiple threads in a dynamic binary translator used to perform instruction set simulation. This is done through a code generation design that allows native code to be executed by any simulated core and adding a mechanism to share native code regions between threads. This is shown to improve the average performance of multi-threaded benchmarks by 1.4x when simulating 128 cores on a quad-core host machine. Secondly, the ahead-of-time code generation system used for executing Android applications is improved through the use of profiling. The thesis investigates the potential for profiles produced by individual users of applications to be shared and merged together to produce a generic profile that still provides a lot of benefit for a new user who is then able to skip the expensive profiling phase. These profiles can not only be used for selective compilation to reduce code-size and installation time, but can also be used for focussed optimisation on vital code regions of an application in order to improve overall performance. With selective compilation applied to a set of popular Android applications, code-size can be reduced by 49.9% on average, while installation time can be reduced by 31.8%, with only an average 8.5% increase in the amount of sequential runtime required to execute the collected profiles. The thesis also shows that, among the tested users, the use of a crowd-sourced and merged profile does not significantly affect their estimated performance loss from selective compilation (0.90x-0.92x) in comparison to when they they perform selective compilation with their own unique profile (0.93x). Furthermore, by proposing a new, more powerful code generator for Android’s virtual machine, these same profiles can be used to perform focussed optimisation, which preliminary results show to increase runtime performance across a set of common Android benchmarks by 1.46x-10.83x. Finally, in such a situation where a new code generator is being added to a virtual machine, it is also important to test the code generator for correctness and robustness. The methods of execution of a virtual machine, such as interpreters and code generators, must share a set of semantics about how programs must be executed, and this can be exploited in order to improve testing. This is done through the application of domain-aware binary fuzzing and differential testing within Android’s virtual machine. The thesis highlights a series of actual code generation and verification bugs that were found in Android’s virtual machine using this testing methodology, as well as comparing the proposed approach to other state-of-the-art fuzzing techniques.
337

Perdas de hexazinona e diuron por escoamento superficial em sistema de cana crua / Hexazinone and diuron runoff in green cane systems

Vaz, Lucas Rafael Lommez 27 October 2016 (has links)
A canavicultura é de extrema importância para o Brasil e para o mundo. O aumento da produção de cana-de-açúcar reflete em maior uso de herbicidas, como o diuron e a hexazinona. A adoção do sistema de cana crua, em que a palha permanece sobre o solo após colheita mecanizada, implica em alteração na dinâmica ambiental destes herbicidas. Portanto, o objetivo deste trabalho foi avaliar as perdas de diuron e hexazinona por escoamento superficial em sistemas de cana crua. O experimento constou de sistema fatorial 3x2x2 (12 tratamentos) com delineamento em blocos casualizados e 4 repetições, totalizando 48 parcelas. Os fatores foram: 3 níveis de palha (0, 50% e 100% da dose = 14 t ha-1); 2 níveis de umidade de solo (10 e 18% v/v) e 2 momentos de chuva (0 e 3 dias após aplicação dos produtos). Sobre as parcelas de 1 m2, foi utilizado um simulador de chuvas ajustado para evento com intensidade de 80 mm h-1 durante uma hora e meia, resultando num volume total precipitado de 120 mm. Um produto comercial contendo diuron e hexazinona foi aplicado na dose de 3 kg ha-1 e calda de 700 L ha-1, conforme recomendações do fabricante. As quantidades de água e sedimentos escoadas foram registradas e as concentrações dos herbicidas analisadas em solução por UPLC. Os resultados foram submetidos à ANOVA e, em caso de interação, as médias foram comparadas pelo teste de Tukey (p<0,05). A quantidade de diuron e hexazinona nos sedimentos foi estimada fazendo uso dos dados de sorção da literatura. A presença de palha sobre o solo reduziu as perdas de água, sedimentos e diuron, mas não teve efeitos sobre as perdas de hexazinona. Em outras palavras, a cobertura morta não reduz as perdas de moléculas muito solúveis, como a hexazinona. As maiores perdas de diuron e hexazinona foram observadas em solução, mesmo no tratamento controle (sem palha), uma vez que a palha reduz a massa de sedimentos desprendida. No entanto, não houve diferença nas perdas entre os dois níveis de palha (50 e 100%), sugerindo que 7 t ha-1 são suficientes para atenuar as perdas de água, sedimentos e diuron. Maiores teores de água no solo (18 versus 10% v/v) implicaram em maiores perdas dos herbicidas por escoamento superficial. Já o momento da chuva não afetou as perdas dos herbicidas, indicando que 3 dias não foram suficientes para a dissipação ou maior sorção dessas moléculas. / Sugarcane is a major crop in Brazil and of great importance to the world. Higher yields implicate in higher use of pesticides, such as diuron and hexazinone. The adoption of green cane system, in which the straw is kept in the soil surface after mechanical harvesting, has changed the environmental behavior of theses herbicides. Therefore, the goal of this research was to evaluate runoff losses of diuron and hexazinone in green cane systems. The 3x2x2 (12 treatments) factorial experiment was performed in a randomized block with 4 replicates. The factors were i) 3 levels of sugarcane straw (0, 50% and 100%, based on a dose of 14 t ha-1); ii) 2 levels of initial soil moisture (10 and 18% VWC), and iii) 2 rainfall periods (0 and 3 dafter herbicides application). A rainfall simulator was adjusted to simulate an 80 mm h-1 rainfall event for one and a half hour (120 mm) over plots of 1 m2. A commercial product containing diuron and hexazinone was used at rate of 3 kg ha-1 dissolved in 700 L ha-1, according to label recommendations. The amounts of water and sediments were registered and herbicides concentrations analyzed by UPLC. Herbicides attached to the sediments were estimated according to sorption data from the literature. The results were evaluated by ANOVA and means compared by Tukey test (p<0.05). Sugarcane straw decreased water, sediments, and diuron losses by runoff, but did not affect hexazinone losses. In other words, crop residues cannot prevent losses of highly soluble molecules, such as hexazinone. Greater herbicides losses were observed in the aqueous phase, even for the control treatment (without straw), since straw reduces the amounts of detached sediments. However, no difference was observed between the two levels of straw (50 and 100%), meaning that 7 t ha-1 is sufficient for mitigating water, sediments, and diuron losses by runoff. Higher soil moisture (18 versus 10%) resulted in higher herbicides runoff. Yet, rainfall period did not affect herbicide losses, indicating that 3 days were not long enough for enhancing these herbicides dissipation or sorption.
338

Certification of an Instruction Set Simulator / Certification d'un simulateur de jeu d'instructions

Shi, Xiaomu 10 July 2013 (has links)
Cette thèse expose nos travaux de certification d'une partie d'un programme C/C++ nommé SimSoC (Simulation of System on Chip), qui simule le comportement d'architectures basées sur des processeurs tels que ARM, PowerPC, MIPS ou SH4. Un simulateur de System on Chip peut être utilisé pour developper le logiciel d'un système embarqué spécifique, afin de raccourcir les phases des développement et de test, en particulier quand la vitesse de simulation est réaliste (environ 100 millions d'instructions par seconde par cœur dans le cas de SimSoC). Les réductions de temps et de coût de développement obtenues se traduisent par des cycles de conception interactifs et rapides, en évitant la lourdeur d'un système de développement matériel. SimSoC est un logiciel complexe, comprenant environ 60 000 de C++, intégrant des parties écrites en SystemC et des optimisations non triviales pour atteindre une grande vitesse de simulation. La partie de SimSoC dédiée au processeur ARM, l'un des plus répandus dans le domaine des SoC, transcrit les informations contenus dans un manuel épais de plus de 1000 pages. Les erreurs sont inévitables à ce niveau de complexité, et certaines sont passées au travers des tests intensifs effectués sur la version précédente de SimSoC pour l'ARMv5, qui réussissait tout de même à simuler l'amorçage complet de linux. Un problème critique se pose alors : le simulateur simule-t-il effectivement le matériel réel ? Pour apporter des éléments de réponse positifs à cette question, notre travail vise à prouver la correction d'une partie significative de SimSoC, de sorte à augmenter la confiance de l'utilisateur en ce similateur notamment pour des systèmes critiques. Nous avons concentré nos efforts sur un composant particulièrement sensible de SimSoC : le simulateur du jeu d'instructions de l'ARMv6, faisant partie de la version actuelle de SimSoC. Les approches basées sur une sémantique axiomatique (logique de Hoare par ex- emple) sont les plus répandues en preuve de programmes impératifs. Cependant, nous avons préféré essayer une approche moins classique mais plus directe, basée sur la sémantique opérationnelle de C : cela était rendu possible en théorie depuis la formalisation en Coq d'une telle sémantique au sein du projet CompCert et mettait à notre disposition toute la puissance de Coq pour gérer la complexitité de la spécification. À notre connaissance, au delà de la certification d'un simulateur, il s'agit de la première expérience de preuve de correction de programmes C à cette échelle basée sur la sémantique opérationnelle. Nous définissons une représentation du jeu d'instruction ARM et de ses modes d'adressage formalisée en Coq, grâce à un générateur automatique prenant en entrée le pseudo-code des instructions issu du manuel de référence ARM. Nous générons également l'arbre syntaxique abstrait CompCert du code C simulant les mêmes instructions au sein de Simlight, une version allégée de SimSoC. À partir de ces deux représentations Coq, nous pouvons énoncer et démontrer la correction de Simlight, en nous appuyant sur la sémantique opérationnelle définie dans CompCert. Cette méthodologie a été appliquée à au moins une instruction de chaque catégorie du jeu d'instruction de l'ARM. Au passage, nous avons amélioré la technologie disponible en Coq pour effectuer des inversions, une forme de raisonnement utilisée intensivement dans ce type de situation. / Approaches based on axiomatic semantics (typically, Hoare logic) are the mostpopular for proving the correctness of imperative programs. However, we prefered totry a less usual but more direct approach, based on operational semantics : this wasmade possible in theory since the development of an operational semantics for theC language formalized in Coq in the CompCert project, and allowed us to use thecomfortable logic of Coq, of much help for managing the complexity of the specification.Up to our knowledge, this is the first development of formal correctness proofs basedon operational semantics, at least at this scale.We provide a formalized representation of the ARM instruction set and addressingmodes in Coq, using an automatic code generator from the instruction pseudo-code inthe ARM reference manual. We also generate a Coq representation of a correspondingsimulator in C, called Simlight, using the abstract syntax defined in CompCert.From these two Coq representations, we can then state and prove the correctnessof Simlight, using the operational semantics of C provided by CompCert. Currently,proofs are available for at least one instruction in each category of the ARM instructionset.During this work, we improved the technology available in Coq for performinginversions, a kind of proof steps which heavily occurs in our setting.
339

Eros?o h?drica sob chuva simulada em diferentes classes de solos e coberturas vegetais na Prov?ncia Petrol?fera de Urucu - Coari, AM / Hydric erosion under simulated rainfall in different soil classes and vegetal covers in the Petroliferous Province of Urucu - Coari, AM

MACHADO, Frederico Santos 27 May 2010 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-05-05T18:33:54Z No. of bitstreams: 1 2010 - Frederico Santos Machado.pdf: 2164167 bytes, checksum: 28047d32a367720ee18ef9cf4c58be45 (MD5) / Made available in DSpace on 2017-05-05T18:33:54Z (GMT). No. of bitstreams: 1 2010 - Frederico Santos Machado.pdf: 2164167 bytes, checksum: 28047d32a367720ee18ef9cf4c58be45 (MD5) Previous issue date: 2010-05-27 / The hydric erosion is one of main environmental impact in Central Amazonia region, causing serious economic consequences for implantation and recovery of operational locations of PETROBRAS S/A oil and natural gas exploration and production sites. This study was carried through in Petroliferous Province of Urucu, municipality of Coari (AM). The objective was to quantify soil loss (SL) and runoff (SD) in different soil classes and under vegetal coverings using a portable rain simulator. Sixteen batteries of tests were done, eight batteries for each soil class (Fluventic Dystrustepts e Kanhaplic Haplustults). For each battery three repetitions had been made in the following covers: forest, forest without litter and grass. The results of Tukey test at 0.05 level showed that soil classes were not significantly different between themselves. On the other hand, the organic carbon percentage and the soil bulk density had greatest importance for the soil loss. These attributes, plus fine sand and clay, influenced most in the runoff. It was also possible to observe that runoff was the attribute of highest correlation with soil loss. The conversion of forest areas into grass increased, at least, four times the water runoff, changing it from 14.2 mm to 57.7 mm in the grass area, and, at least, two times loss of soil mass, achieving the value of 35.68 t.ha-1.year-1 in the grass area. Although with these values, grassy areas only differed significantly from the forest areas in the runoff. The runoff values tend to increase twofold when litter is removed from the forest soils, while the soil losses increased 40%. The attributes that were important for the soil classes were the same for cover types, however with differences in the attribute clay content for soil loss, and coarse sand for runoff. For the studied treatments, the attribute that showed highest correlation with soil loss was runoff. / A eros?o h?drica ? um dos principais impactos ambientais na regi?o da Amaz?nia Central, causando s?rias conseq??ncias, inclusive econ?micas, para a implanta??o e recupera??o de loca??es operacionais de explora??o e produ??o de petr?leo e g?s natural da PETROBRAS S/A. Este estudo foi realizado na Prov?ncia Petrol?fera de Urucu, munic?pio de Coari (AM) e teve como objetivo quantificar a perda de solo (PS) e o escoamento superficial (ES) em diferentes grupos de solo e coberturas vegetais, utilizando um simulador de chuva port?til. Foram efetuadas 16 baterias de testes, sendo 4 baterias para cada grupo de solo (ARGISSOLO AMARELO Al?tico, ARGISSOLO VERMELHO-AMARELO Al?tico, CAMBISSOLO H?PLICO Al?tico e CAMBISSOLO H?PLICO Tb Distr?fico). Em cada bateria foram realizados tr?s repeti??es nas seguintes coberturas: floresta, floresta sem serrapilheira e gram?nea. As classes de solo n?o diferiram significativamente entre si ao n?vel de 5%, segundo o teste de Tukey. Para a PS, a porcentagem de carbono org?nico e a densidade do solo t?m grande import?ncia para os grupos de solo. Esses atributos, mais a areia fina e argila influenciaram o ES. Tamb?m foi poss?vel observar que o escoamento foi o atributo com maior coeficiente de correla??o com a perda de solo. A convers?o das ?reas de floresta em gram?nea aumentou em no m?nimo quatro vezes a l?mina de ?gua escoada, passando de 14,2 mm para 57,7 mm na gram?nea e, no m?nimo, duas vezes a massa de solo perdida, chegando a 35,8 t.ha-1.ano-1 na gram?nea. Apesar desses valores, as ?reas cobertas por gram?neas apenas diferiram significativamente das ?reas de florestas em rela??o ao ES. Quando se retira a serrapilheira em solos florestais, os valores de escoamento dobram, enquanto que as perdas aumentam em 40%. Os atributos que tiveram import?ncia para as classes de solo foram os mesmos para os tipos de coberturas, por?m com diferen?as no atributo teor de argila para a perda de solo e no teor de areia grossa para o escoamento. Para os tratamentos estudados, o escoamento continua sendo o atributo com maior coeficiente de correla??o com a perda.
340

Construção de uma bancada de ensaio para avaliação de mecanismos dosadores de sementes / Construction of a workbench of essay for evaluation of mechanisms distributor of seeds

Kempski, Luciano Aparecido 19 June 2006 (has links)
Made available in DSpace on 2017-07-10T19:24:37Z (GMT). No. of bitstreams: 1 Luciano Aparecido Kempski.pdf: 1024512 bytes, checksum: 05341aec87667985a0d8254a3699a994 (MD5) Previous issue date: 2006-06-19 / The current work aimed the construction of a benches group for simulating displacement speeds of sowers. The speeds simulator was performed and was carried out in the mechanical trials laboratory located at UTFPR - campus Medianeira, and the assays of system´s evaluation were performed at the Agricultural Engineering Experimental Nucleous - AEEN, which belongs to West of the Paraná State University- campus Cascavel. The benches group of assay or speeds simulator is composed by two rolls: one of this set through a hydraulic engine brand TRW, and other one used as support for the wheels system of the sower. The hydraulical engine was connected to the hydraulical command of the tractor through fast connection, which become the coupling and withdraws of hoses easier when stationary assay of displacement speeds is performed. The assays were performed aiming the determination of the maximum rotation for the hydraulical engine without load and also with the sower on the rolls, in order to get ranges of displacement speeds in a fast and accurated form. The results obtained of the regulating valve´s opening and closing (A1 the A7) forms, in function of the hydraulic engine´s rotation and the displacement speed, are presented in figures, tables and relation ´s graphs. The tables present the average values and the hydraulical engine without load is presented by the comparision between the averages. For the hydraulical engine without load can be reach speeds ranged from 20 to 375 rpm in accordance to the results obtained, which is linked to the enough displacement speeds. The benches group essay was showed as functional and also presented compact structure, with the flowing rangel of speeds verified through the pairs of gear. Its versatility is evidenced by the use of the hydraulic circuit of the tractor as energy source for the speeds simulator.It was observed that the regulating valve of outflow was efficient for the regulation of the hydraulical engine´s speed when it was assayed with load; it means that, with the sower on the cylinders. The results obtained allow to present the following conclusions: it is a too much suitable resource, considering the easiness, quickness and the capacity for obtaining several regulations, allowing the simulation of displacement speeds from 3,23 to 13,89 km.h-1; it fits perfectly in sowers with pneumatic wheels; the weight and size allow the transport without difficulties, provide conditions to evaluate the distribuition mechanisms of the seeds or fertilizer, and avaluation the longitudinal distribution of seeds, in accordance to the evaluation criteria of performing in spacements: normal, double and defective. / Este trabalho teve como objetivo a construção de uma bancada para simulação de velocidades de deslocamento de semeadoras. O simulador de velocidades foi projetado e montado no laboratório de processos mecânicos da UTFPR - campus Medianeira. Os ensaios de avaliação do sistema foram realizados no Núcleo Experimental de Engenharia Agrícola - NEEA, pertencente à Universidade Estadual do Oeste do Paraná campus Cascavel. A bancada de ensaio ou simulador de velocidades é formada por dois rolos: um acionado por meio de um motor hidráulico marca TRW e o outro utilizado como apoio para o rodado da semeadora. O motor hidráulico foi conectado ao comando hidráulico do trator por meio de engates rápidos, o que facilita o acoplamento e retirada das mangueiras, no momento da realização do ensaio estacionário de velocidades de deslocamento. Os ensaios foram realizados para a determinação da rotação máxima do motor hidráulico sem carga e com a semeadora sobre os rolos a fim de obter faixas de velocidade de deslocamento de forma precisa e rápida. Os resultados obtidos sobre a relação da abertura e fechamento da válvula reguladora (A1 a A7), em função da rotação do motor hidráulico e da velocidade de deslocamento, são apresentados em forma de figuras, tabelas e gráficos. As tabelas apresentam os valores médios e a comparação entre as médias está representada nos gráficos 21 e 22. Com o motor hidráulico sem carga podem-se alcançar velocidades desde 20 rpm até 375 rpm, conforme os resultados obtidos que se relacionam com as velocidades de deslocamento. A bancada de ensaio apresentou-se funcional e de estrutura compacta, com a faixa de escalonamento de velocidades verificada pelos pares de engrenagem. Sua versatilidade é evidenciada pelo uso do circuito hidráulico do trator como fonte de energia para acionamento do simulador de velocidades. Observou-se que a válvula reguladora de vazão foi eficiente na regulagem da velocidade do motor hidráulico quando ensaiado com carga, ou seja, com a semeadora sobre os cilindros. Os resultados obtidos permitem apresentar as seguintes conclusões: a bancada mostrou-se um recurso bastante adequado, considerando-se a facilidade, rapidez e a capacidade de conseguir várias regulagens, permitindo a simulação de velocidades de deslocamento de 3,23 a 13,89 km.h-1; adapta-se perfeitamente à semeadora com rodado pneumático, o peso e tamanho permitem o transporte sem dificuldades; fornece condições de avaliação de mecanismos distribuidores de sementes e fertilizantes; e avaliar a distribuição longitudinal de sementes, de acordo com os critérios de avaliação de desempenho em espaçamentos: normal, duplos e falhos.

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