In this work, nozzle clogging in the submerged entry nozzle in continuous casting of Al killed steels has been studied. The study has been based on low silicon Al killed SAE 1006 (1.2006) and SAE 1008 (1.2008) grades. In this study, castabilities of 75 heats for 1.2006 steel grades and 75 heats for 1.2008 steel grades have been investigated. Castabilities of the experimental heats have been found to be affected by Al content in oxide form (Aloxy) and Ca content of the liquid steel. Castabilities have been found to decrease with increase in Aloxy and to increase with increase in Ca content and Ca/Aloxy ratio. Reoxidation has been found not to affect the castability appreciably.

Aquifer Storage and Recovery (ASR) involves the injection of water into an aquifer for subsequent recovery from the same well. Whilst ASR provides a competitive alternative to reservoir storage, a lack of precedence of successful schemes and uncertainties with respect to regulatory requirements, and abstracted water quality and quantity have limited its implementation in the UK. The ambition of this research is to improve understanding of these impediments with particular reference to the Sherwood Sandstone aquifer. Drawing on existing project review and risk management approaches, a decision support tool to help scheme designers scope ASR scheme potential and challenges was developed and tested. The tool provides practitioners with a systematic method for early stage evaluation of ASR schemes with testing confirming broad value and alignment with business processes. Limitations on the recovery of recharged water was investigated through a critical literature review on clogging with geochemical, biological, physical and gaseous binding processes identified as the most likely mechanisms to impact an ASR scheme in this aquifer. Water quality changes during storage and the impact of storage period on recovered water quality were investigated in the laboratory using ASR simulating columns, with storage times of 15, 20, 30 and 60 days. Water quality improvements such as biodegradation of disinfection by-products, denitrification and sulphate reduction were observed. However recovered water quality deteriorated with respect to iron, arsenic, manganese, total organic carbon and nickel. These results, together with the review of regulations conducted as part of decision support tool development, suggest that the current interpretation of the Water Framework Directive requirements is overly restrictive and is deterring wider implementation of ASR in the UK. Conclusions focus on the need for a more appropriate approach to regulating ASR schemes, in particular, one which adopts a risk based approach to determining water quality standards.

Submitted by Lara Oliveira (lara@ufersa.edu.br) on 2017-04-27T00:21:39Z No. of bitstreams: 1 KetsonBS_DISSERT.pdf: 1323947 bytes, checksum: 3651efde26f75bdba2353aa069b19d6f (MD5) / Made available in DSpace on 2017-04-27T00:21:40Z (GMT). No. of bitstreams: 1 KetsonBS_DISSERT.pdf: 1323947 bytes, checksum: 3651efde26f75bdba2353aa069b19d6f (MD5) Previous issue date: 2012-08-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The cashew crop is a major agricultural activities on national scene, having great economic value to the farmer, and consequently for the agribusiness the country. In northeastern Brazil there are a great number of processing cashew nut industries, generating a significant volume of wastewater. Thus, the scope of this paper was to evaluate the performance of drip irrigation systems operating with wastewater cashew nuts under different operating pressures. The activities were conducted at the Experimental Unit for Water Reuse (UERA), located in Park Zoobotânico, Universidade Federal Rural do Semi - Arid (UFERSA). In this study we tested three types of emitters (G1, G2 and G3), with different nominal flows, orifice areas and labyrinth length. The influence of operating pressures P1 (70kPa), P2 (140kPa), P3 (210 kPa) and P4 (280 kPa) on emitters clogging operating with cashew nuts wastewater were evaluated. The CUC, CUD, CVQ and Q were determined for each 20h of operating. The experiment was mounted on the split split plot scheme, the design completely randomized design with three replications. The data were subjected to analysis of variance and regression and test average. The results indicated that the cashew nuts wastewater represents risk of drippers clogging for the characteristics pH, calcium, magnesium, manganese, suspended solids and total coliforms; the formation of biofilm resulting from the interaction between the agents physical, chemical and biological provided partial clogging of the emitter and reduction on effluent application uniformity of the units irrigation; the units irrigation under service pressure P1 (70 kPa) had higher drippers clogging in relation the service pressures P2 (140kPa), P3 (210kPa) and P4 (280 kPa); the dripper G1 was more susceptible to clogging compared to the other, due to the greater labyrinth length; and the drip G1 was the most indicated for operation at the operating service pressure P2 (140 kPa), while the drip G2 was most appropriate under pressure service P1 (70 kPa) / A cajucultura é uma das maiores atividades agrícolas no cenário nacional, possuindo grande valor econômico para o agricultor, e consequentemente para o agronegócio do país. No nordeste brasileiro existe grande número de indústrias do processamento da castanha do caju, gerando um volume significativo de águas residuárias. Sendo assim, foi realizado o presente trabalho com o intuito de avaliar o desempenho de sistemas de irrigação por gotejamento operando com água residuária da castanha de caju sob diferentes pressões de serviço. As atividades foram realizadas na Unidade Experimental de Reuso de Água (UERA), localizada no Parque Zoobotânico da Universidade Federal Rural do Semi - Árido (UFERSA). Nesse estudo foram ensaiados três tipos de gotejadores (G1, G2 e G3), com diferentes vazões nominais, áreas do orifício e comprimento dos labirintos. Verificou-se, também, as influências das pressões de serviço P1 (70kPa), P2 (140kPa), P3 (210 kPa) e P4 (280 kPa) no entupimento dos gotejadores operando com água residuária gerada no processamento da castanha de caju. Avaliou-se, a cada 20h de funcionamento, o CUC, CUD, CVQ e Q. O experimento foi montado no esquema de parcelas subsubdivididas, no delineamento inteiramente casualizado com três repetições. Os dados foram submetidos às análises de variância e de regressão e teste de média. Os resultados indicaram que a água residuária gerada no processamento da castanha de caju representa risco de obstrução de gotejadores em relação às características pH, cálcio, magnésio, manganês, sólidos suspensos e coliformes totais; a formação de biofilme resultante da interação entre os agentes físico, químico e biológico propiciou entupimento parcial dos gotejadores e, consequentemente, redução na uniformidade de aplicação de efluente das unidades de irrigação; as unidades de irrigação que funcionaram na pressão de serviço P1 (70 kPa) apresentaram maior nível de entupimento de gotejadores em relação àquelas com as pressões de serviço P2 (140 kPa), P3 (210kPa) e P4 (280 kPa); o gotejador G1 foi mais suscetível ao entupimento em relação aos demais, devido ao maior comprimento de labirinto; e o gotejador G1 foi o mais indicado para operação sob a pressão de serviço de P2 (140 kPa), enquanto o gotejador G2 na pressão de P1 (70 kPa) foi a combinação mais adequada / 2017-04-26

Submitted by Socorro Pontes (socorrop@ufersa.edu.br) on 2017-09-11T15:01:23Z No. of bitstreams: 1 JorgeLOC_TESE.pdf: 1815389 bytes, checksum: e1806d37e3ce1f16a7256649edcda60b (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-09-11T16:28:08Z (GMT) No. of bitstreams: 1 JorgeLOC_TESE.pdf: 1815389 bytes, checksum: e1806d37e3ce1f16a7256649edcda60b (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-09-11T16:28:40Z (GMT) No. of bitstreams: 1 JorgeLOC_TESE.pdf: 1815389 bytes, checksum: e1806d37e3ce1f16a7256649edcda60b (MD5) / Made available in DSpace on 2017-09-11T16:29:54Z (GMT). No. of bitstreams: 1 JorgeLOC_TESE.pdf: 1815389 bytes, checksum: e1806d37e3ce1f16a7256649edcda60b (MD5) Previous issue date: 2017-07-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Drip irrigation system in the radiation area of the agricultural crop in order to provide that a partner of the soil is close to the field capacity. In this irrigation system as dripping tapes are exposed to physical-chemical and microbiological agents that increase the appearance of emitter obstruction, reducing the operational life cycle of the system that operate with water of inferior quality. The objective of this study was to study the variation of irrigation water temperature and salinity as factors that contribute to the process of obstruction of the tapes, reducing its useful life, control solution of flow rate uniformity of the emitters of the drip tapes under laboratory conditions. For this, an experimental bench was set up not Laboratory of Machine Instrumentation and Agricultural Mechanization of the Universidade Federal Rural do Semi-Árido, in Mossoró-RN; Where the experimental tests were carried out with three types of drip tapes operated under controlled conditions of temperature, water salinity and service pressure. The experimental bench has the following dimensions: 1,50m x 3,50m (width and length), height of 1,00 m and 1,20 m (low point and highest point respectively). On the same saw, fixed four fiber cement tiles in an area of 0.90 m x 3.00 m (width and length), with slope of 8% and at its base to insert a collecting trough connected to the ground water reservoir of 0.10m3. To allow a recirculation of the test water, a 1/4 hp centrifugal pump was used. Four lines of tapes with three meters of length were used in the workbench, which were submitted to short test cycles, established at 100, 250, 500 and 750 hours of operation and water temperature of 20 and 30ºC. To control the temperature of the water with the heating system with power of 2.00 kW and cooling of 7.04 kW. The electrical conductivity of water ranged from 0.52 dS m-1 to 2.56 dS m-1. After the end of each cycle of operation, samples of the tapes were collected for scanning electron microscopy of the holes and internal walls. The flow rate and the Distribution Uniformity Coefficient were used to monitor the hydraulic performance of the drip tapes. The results indicated that the increase of salinity of the irrigation water resulted in a decrease in the flow rate of the drip irrigation system, without causing a change in the classification of the Distribution Uniformity Coefficient. Water quality analyzes indicated a potential risk for soil sodification. The increase in temperature and salinity increased the formation of microorganisms and precipitates of calcium, resulting in increased frequency of maintenance in the system / No sistema de irrigação localizada por gotejamento á água é aplicada em baixa intensidade e alta frequência na região radicular da cultura agrícola de forma a propiciar que a umidade do solo esteja próxima à capacidade de campo. Neste sistema de irrigação as fitas gotejadoras são expostas a agentes físico-químicas e microbiológicas que potencializam o surgimento de obstrução dos emissores, reduzindo o ciclo de vida operacional do sistema que operam com água de qualidade inferior. O presente trabalho objetivou estudar a variação da temperatura e salinidade da água de irrigação como fatores que contribuem para o processo de obstrução das fitas gotejadoras, reduzindo sua vida útil, sob os parâmetros de redução da uniformidade da vazão dos emissores das fitas gotejadoras em condições laboratoriais. Para isto, montou-se uma bancada experimental no Laboratório de Instrumentação de Máquinas e Mecanização Agrícola da Universidade Federal Rural do Semi-Árido, em Mossoró-RN; onde foram realizados os ensaios experimentais com três tipos de fitas gotejadoras operadas em condições controladas de temperatura, salinidade da água e pressão de serviço. A bancada experimental apresenta as seguintes dimensões 1,50m x 3,50m (largura e comprimento), altura de 1,00m e 1,20m (ponto maio baixo e ponto mais elevado respectivamente). Sobre a mesma foram fixadas quatro telhas de fibrocimento numa área de 0,90m x 3,00m (largura e comprimento), com declividade de 8% e na sua base foi inserida uma calha coletora conectada ao reservatório térreo de 0,10m3. Para permitir a recirculação da água do ensaio foi utilizado um conjunto motobomba centrífuga de 1/4cv. Na bancada foram utilizadas quatro linhas de fitas gotejadoras com três metros de comprimento cada, sendo estas submetidas a ciclos de ensaios de curta e longa duração, estabelecido em 100, 250, 500 e 750 h de operação, e temperatura da água de 20 e 30ºC. Para o controle da temperatura da água foi utilizado sistema de aquecimento com potência de 2,00 kW e refrigeração de 7,04 kW. A condutividade elétrica da água variou de 0,52 dS m-1 a 2,56 dS m-1. Após o término de cada ciclo de operação foram coletadas amostras das fitas para a realização de microscopia eletrônica de varredura dos orifícios e paredes internas. Empregou-se a vazão e o Coeficiente de Uniformidade de Distribuição no monitoramento do desempenho hidráulico das fitas gotejadoras. Os resultados obtidos indicaram que o aumento da salinidade da água de irrigação acarretou o decréscimo da vazão do sistema de irrigação localizada por gotejamento, sem ocasionar alteração da classificação do Coeficiente de Uniformidade de Distribuição. As análises da qualidade da água indicaram risco potencial para sodificação do solo. O aumento da temperatura e salinidade potencializou a formação de microrganismos e precipitados de cálcio, resultando no aumento da frequência de manutenções no sistema / 2017-09-11

This Dissertation is devoted to computational study of the solidification, dynamics and mechanics of model semiflexible polymers with variable chain flexibility as well as a computational investigation of the clogging phenomena observed in granular materials. Chain stiffness is an intrinsic factor that governs single-chain flexibility. It plays a critical role in the physics of polymeric materials. In this work, we employ a coarse-grained polymer model in which chain stiffness can be tuned by a single parameter (bending stiffness kb) that yields chain shape ranging from coil-like to rod-like in the flexible and very stiff limit respectively. In chapter 2, we focus on how chain stiffness affects how polymer melts solidify under thermal cooling. We observe a strong dependence of the solid-state morphology (formed after cooling) upon chain flexibility. In the flexible limit, we find that monomers possess crystalline order while chains retain random-walk like structure. In higher stiffness regime glass formation is obtained while nematic ordering typical of lamellar precursors coexists with close-packing in the rod-like limit. Surprisingly we observe various structures ranging from spiral, to multi-domain nematic phases in the intermediate values of kb. In chapter 3 we go a step further to relate the solidification behaviors of chains discussed in chapter 2 to their melt dynamics. We probe the microstructure and the dynamics of flexible, intermediate-stiffness and rod-like chains. We find that melts of flexible and stiff chains that crystallize under cooling show simple and fast dynamics with Arrhenius temperature dependence. Interestingly, the intermediate-stiffness chains exhibit Vogel-Fulcher dynamical relaxation typical of fragile glass-formers even though their ground states is a nematic-close-packed crystal. There is no compelling argument based on static micro-structure change explaining this dynamical arrest to be found. However, we find that the dynamics of intermediate-stiffness chains is dominated by the stringlike cooperative motion that correlates along their chain backbones. This cooperative rearrangement which is absent in other systems appears to be the main cause of the dynamical arrest observed for intermediate-stiffness chains. In chapter 4, we turn to another class of materials where the negligible contribution of thermal fluctuations gives rise to an interesting phenomenon, i.e. the clogging transition. Clogging is a probabilistic event that occurs through a transition from a homogeneous flowing state to a heterogeneous or phase separated jammed state. The granular system under study is an assemble of bidisperse disks externally driven through a two dimensional periodic substrate. We find that the probability for clogging strongly depend on particle packing, obstacle number and the driving direction. Surprisingly, under relevant conditions we observe a size-specific clogging transition in which the smaller species get trapped while the larger species keep flowing. Chapter 5 returns to discuss the polymer solidification in the context of isostaticity. Results from the simulations of semiflexible polymers described in chapter 2 allow us to derive a generalized isostaticity criterion that can be applied to finite-stiffness chains. The new criterion is based on the characteristic ratio C which characterizes the slow freezing out of configurational freedom of chains as chain stiffness increases. The results of the average coordination number at solidification Z(Ts) suggest a link between jamming in athermal systems and solidification in their thermal counterparts. Finally, in chapter 6 we study the effect of chain stiffness on the mechanical response of glassy polymers. We investigate shear deformation of three systems with a different degree of entanglement. We find that loosely entangled chains display strong shear banding and undergo fracture via chain pullout. In contrast, tightly entangled chains fail at high enough strain along a well-defined plane via chain scission shortly after chains are pulled taut. We explain these chain-stiffness-dependent behaviors qualitatively using the segmental packing efficiency argument and quantitatively using modern plasticity measures

Le générateur de vapeur est un composant essentiel du réacteur à eau pressurisée. Après 15 à 20 ans de fonctionnement du GV, un phénomène de colmatage est observé, qui induit le bouchage du passage folié entre les tubes GV et la plaque entretoise. Ce phénomène peut avoir de graves conséquences pour le fonctionnement de la centrale nucléaire. L’objectif majeur de cette thèse est d’approfondir les connaissances des mécanismes responsables de la formation du colmatage en identifiant et hiérarchisant les processus prépondérants. L’installation COLENTEC est un outil expérimental conçu pour reproduire des dépôts dans des conditions représentatives d’un GV. La post-caractérisation microscopique a permis d’identifier la contribution du phénomène de précipitation et le rôle d’initiation de la passivation du matériau. Les formes spécifiques du colmatage, lipping à l’entrée et rides le long de la plaque entretoise, n’ont pas été observées dans les essais COLENTEC. Cela peut être provoqué par l’absence de particules dans la section d’essai ou une vitesse insuffisante du fluide. Le flashing et le phénomène électrocinétique ont été supposés contribuer à la formation du colmatage. Une collaboration avec l’Université de Manchester a été établie au cours de ce travail afin d’étudier expérimentalement le phénomène électrocinétique. Les travaux effectués ont permis de mieux comprendre ce phénomène et de suggérer son influence considérable dans la formation du colmatage. Des quantifications numériques de chaque phénomène ont été réalisées, prédisant un rôle prédominant du phénomène électrocinétique. / The steam generator is an essential component in PWR. After 15-20 years of functioning, an obstruction by deposits of flow holes between Tube Support Plate (TSP) and primary tubes is observed, called TSP clogging. This phenomenon may lead to dramatic consequences for nuclear power plant operation. The aim of this thesis is to deepen the understanding of the mechanisms responsible for TSP clogging by identifying and prioritizing the preponderant processes. COLENTEC is an experimental facility designed to reproduce TSP clogging deposits under representative conditions. Microscopic characterizations allowed revealing the deposit formation by precipitation and the initiation role of material passivation in deposit formation. Lipping and ripple forms, specifying TSP clogging, were not observed in COLENTEC tests. This is suggested to be caused by insufficient concentration of suitable particles at the test section. Particle deposition is supposed to be essential for the formation of lipping deposits. Electrokinetic and flashing phenomena are supposed to contribute to TSP clogging formation. An experimental collaboration with the University of Manchester was established to better understand the clogging formation by investigating the role of electrokinetic phenomenon. This study allowed reforming deposits with lipping and ripple forms as observed in EDF steam generators. Electrokinetic involvement, strongly affected by flow velocity, was considerably suggested in TSP clogging formation. Numerical quantification of deposit formation by each phenomenon was performed and compared to EDF feedbacks. Electrokinetic phenomenon was found to play a predominant role.

Made available in DSpace on 2014-06-11T19:26:47Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-06-21Bitstream added on 2014-06-13T18:30:34Z : No. of bitstreams: 1 brauer_rl_me_botfca.pdf: 786217 bytes, checksum: fdfb7a5da26b6d788caa4ede1650975d (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / Com o propósito de avaliar a susceptibilidade de dois tipos de gotejadores ao processo de entupimento por ferro, foi conduzido um experimento em uma bancada de ensaios no Laboratório de Ensaio de Equipamentos para Irrigação do Departamento de Engenharia Rural da Universidade Estadual Paulista “Júlio de Mesquita Filho” – Campus de Botucatu. O ensaio corresponde ao processo de entupimento, e foram avaliados os seguintes modelos de gotejadores NaanDanJain: NaanPC laranja e NaanPC azul. Foram utilizados segmentos de tubos, totalizando 25 emissores, onde se mediu a vazão com a pressão de 150 KPa, com três repetições para cada gotejador. A água utilizada no ensaio foi proveniente do lago do Departamento de Engenharia Rural que é comumente utilizado para irrigações de experimentos. Posteriormente foram calculados: Vazão Média, Coeficiente de Variação de Vazão (C.V.Q), Uniformidade de Distribuição da Água (C.U.D), Coeficiente de Uniformidade de Christiansen (C.U.C) e Vazão Relativa (V.R.). Foi utilizado delineamento experimental estatístico de blocos inteiramente casualizados, com fatorial 2x2x7, com três repetições, sendo o primeiro fator os tratamentos com ferro, o segundo fator os tipos de gotejadores e o terceiro fator o tempo. Os resultados obtidos não apontaram diferença significativa nas diferentes doses de ferro. Entretanto, os resultados apontaram diferença significativa na interação gotejador x tempo e coeficiente de uniformidade de Christiansen (CUC) e vazão relativa (V.R.) / The objective of this study was to evaluate the susceptibility of clogging by iron in two types of drippers using a test bank located at the Irrigation Experimental Laboratory in the Department of Agricultural Engineering of “Sao Paulo State University Julio de Mesquita Filho - Campus of Botucatu, Sao Paulo state. The experiment aims to study the clogging process, evaluating 2 models of drippers NaanDanJain: NaanPC orange and NaanPC blue. It was used tube segments, totaling 25 drippers, using pressure of 150 kPa, with 3 repetitions for each dripper. The water used in the test was from the lake of the Department of Agricultural Engineering which is commonly used for irrigation experiments. It was calculated: the average discharge, the variation coefficient of discharge (CVQ), the uniformity coefficient of distribution (CUD), the uniformity coefficient of Christiansen (CUC) and the relative discharge (VR). It was used statistical experimental design of randomized blocks, with a 2x2x7 factorial with three replications, with the first factor treatment with iron, the second factor the types of drippers and the third factor the time. The results showed no significant difference in different doses of iron. However, the results indicated significant differences in drip x time interaction and the Christiansen uniformity coefficient (CUC) and relative discharge rate (VR)

Made available in DSpace on 2014-06-11T19:26:47Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-01-13Bitstream added on 2014-06-13T19:14:04Z : No. of bitstreams: 1 fugiwara_at_me_botfca.pdf: 2105013 bytes, checksum: f44483a139566285646f1112ff6fd738 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / O presente trabalho teve como objetivo avaliar a variação da uniformidade de vazão, utilizando água com alto teor de ferro em microaspersores NaanDan autocompensantes, bocal marrom 35 L/h, foram testados no campo no Sítio Bocaina, localizado no município de Lençóis Paulista-SP, logo após 120 horas de uso foi retirado do campo e colocados em uma bancada no Laboratório de Irrigação e Drenagem da UNESP, em Botucatu –SP, onde foram submetidos a três sistemas (Tipo Malha, Tipo Linha Lateral e Tipo Serpentina) de irrigação, verificando inclusive sua pressão dos emissores. Através de coletas de água analisando sua qualidade e determinando os teores de ferro presentes que variaram de 1,6 á 2,6 mg/l, para testes na irrigação em microaspersores no campo. Os resultados mostraram que o ferro prejudica na vazão do microaspersor dependendo da pressão e do sistema utilizado, os sistemas tipo malha e linha lateral se mostram superiores aos do tipo serpentina. / This study aimed to evaluate the variation of uniformity of flow, using water with high iron content in microsprinklers auto Naan Dan, brown nozzle 35 L / h, were tested in the field Bocaina Site, located in Lençois Paulista-SP , after 120 hours of use of the field was removed and placed on a bench in the Laboratory of Irrigation and Drainage of UNESP, Botucatu-SP, which were submitted to three systems (Mesh Type, Type and Type Lateral Line Serpentina) from irrigation, including checking of the pressure transmitters. By analyzing samples of water and its quality determines the levels of iron present ranging from 1.6 to 2.6 mg / l for tests on irrigation in microsprinklers field. The results showed that iron affect the flow of microsprinklers depending on the pressure and the system used, the systems mesh type and lateral line are shown above the type of coil.

Made available in DSpace on 2014-06-11T19:28:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-12-21Bitstream added on 2014-06-13T19:58:01Z : No. of bitstreams: 1 silva_er_me_jabo.pdf: 2805002 bytes, checksum: 1edb5322d15c1af6d99d144fbc53004c (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A pesquisa teve como objetivo avaliar o desempenho de um sistema de aeração, decantação e filtragem, quanto à prevenção de entupimento dos emissores e avaliar uniformidade de distribuição da água no sistema de irrigação por gotejamento na época de sua implantação e após um ano de utilização do sistema de prevenção. O trabalho foi realizado na Fazenda Estância Tropical, no município de Barretos – SP, no período de março de 2008 a fevereiro de 2009, realizando-se determinações físicas e químicas da água, ao longo do sistema de aeração, decantação e filtragem, que foi eficiente para a melhoria da qualidade de água, reduzindo os níveis de risco de entupimento de severo para médio e de médio para baixo. Todas as variáveis analisadas diferenciaram a qualidade da água entre os pontos de amostragem do sistema de tratamento, com exceção do Fe+2. Para sólidos em suspensão, turbidez, sólidos dissolvidos e ferro total, os valores reduziram-se pelo uso do sistema proposto, melhorando a qualidade da água. Após um ano de funcionamento do sistema de prevenção, os coeficientes utilizados para determinar a uniformidade de distribuição de água apresentaram valores acima de 80%, sendo classificados como excelente, bom e muito bom / The research aimed to evaluate the performance of aeration, sedimentation and filtration system for the prevention of emitters clogging and evaluate the water distribution uniformity of one drip irrigation system at the time of its implementation and after a year using the prevention system. The research was conducted in the Estancia Tropical farm, in the municipality of Barretos – SP, Brazil, from March 2008 to February 2009, carrying out physical and chemical determinations of water along the aeration, sedimentation and filtration system, which was efficient for improving water quality by reducing levels of risk of clogging of severe to medium and medium to low. All variables differed water quality between the collection points of the treatment system with the exception of Fe+2. For suspended solids, turbidity, dissolved solids and total iron values were reduced by the use of the proposed system, improving water quality. After a year of prevention, the coefficients used to determine the uniformity of water distribution had values above 80%, being classified as excellent, good and very good

Resumo: A pesquisa teve como objetivo avaliar o desempenho de um sistema de aeração, decantação e filtragem, quanto à prevenção de entupimento dos emissores e avaliar uniformidade de distribuição da água no sistema de irrigação por gotejamento na época de sua implantação e após um ano de utilização do sistema de prevenção. O trabalho foi realizado na Fazenda Estância Tropical, no município de Barretos - SP, no período de março de 2008 a fevereiro de 2009, realizando-se determinações físicas e químicas da água, ao longo do sistema de aeração, decantação e filtragem, que foi eficiente para a melhoria da qualidade de água, reduzindo os níveis de risco de entupimento de severo para médio e de médio para baixo. Todas as variáveis analisadas diferenciaram a qualidade da água entre os pontos de amostragem do sistema de tratamento, com exceção do Fe+2. Para sólidos em suspensão, turbidez, sólidos dissolvidos e ferro total, os valores reduziram-se pelo uso do sistema proposto, melhorando a qualidade da água. Após um ano de funcionamento do sistema de prevenção, os coeficientes utilizados para determinar a uniformidade de distribuição de água apresentaram valores acima de 80%, sendo classificados como excelente, bom e muito bom / Abstract: The research aimed to evaluate the performance of aeration, sedimentation and filtration system for the prevention of emitters clogging and evaluate the water distribution uniformity of one drip irrigation system at the time of its implementation and after a year using the prevention system. The research was conducted in the Estancia Tropical farm, in the municipality of Barretos - SP, Brazil, from March 2008 to February 2009, carrying out physical and chemical determinations of water along the aeration, sedimentation and filtration system, which was efficient for improving water quality by reducing levels of risk of clogging of severe to medium and medium to low. All variables differed water quality between the collection points of the treatment system with the exception of Fe+2. For suspended solids, turbidity, dissolved solids and total iron values were reduced by the use of the proposed system, improving water quality. After a year of prevention, the coefficients used to determine the uniformity of water distribution had values above 80%, being classified as excellent, good and very good / Orientador: José Renato Zanini / Coorientador: Jairo Osvaldo Cazetta / Banca: Luiz Carlos Pavani / Banca: Rubens Duarte Coelho / Mestre