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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.
1

Sistema de irrigação de baixa pressão e baixo custo para culturas em fileiras e adensadas

Xavier, Alyssandny Francisco Matos 28 July 2016 (has links)
Submitted by Lara Oliveira (lara@ufersa.edu.br) on 2017-01-31T20:46:57Z No. of bitstreams: 1 AlyssandnyFMX_DISSERT.pdf: 1896016 bytes, checksum: 1029c37a590c0861713067752d4df5e4 (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-03-21T14:53:04Z (GMT) No. of bitstreams: 1 AlyssandnyFMX_DISSERT.pdf: 1896016 bytes, checksum: 1029c37a590c0861713067752d4df5e4 (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-03-21T14:53:18Z (GMT) No. of bitstreams: 1 AlyssandnyFMX_DISSERT.pdf: 1896016 bytes, checksum: 1029c37a590c0861713067752d4df5e4 (MD5) / Made available in DSpace on 2017-03-21T15:06:48Z (GMT). No. of bitstreams: 1 AlyssandnyFMX_DISSERT.pdf: 1896016 bytes, checksum: 1029c37a590c0861713067752d4df5e4 (MD5) Previous issue date: 2016-07-28 / The semi-arid to present unfavorable weather conditions for agriculture, with water deficit during most time of the year, poorly distributed rainfall and high temperatures, require irrigation for crop development. In the perspective of sustainable agriculture, drip irrigation is the method of more efficient use of water, which has attracted farmers and agricultural companies. Irrigation systems by gravity in closed conduits are the most suitable for family farmers, due to low cost and operate at low pressures. This study aimed to develop a similar irrigation system to the bubbler which will enable water form located in crop plants in rows and dense. Flow-diameter-length-hydraulic load curves were established. A sizing model was fitted to the irrigation system where feed tests were carried out in the field in different soil, to establish a model that relates flow rate, length of the irrigation bowl-time and eventually the installation of the irrigation system which evaluated the uniformity of flow in the area. The installation of the irrigation system was carried out in the municipality of Upanema / RN, in a Cambisol medium texture, cultivated with forage cactus using water supply Regarding the water breakthrough curves test soil, it can be said that the potential equations were similar logarithmic equations. It is recommended the use of potential model to represent the data of the water feed test on the ground curve. The prototype of the load losses virtually showed no change and were minimal, since the installed project this was very significant and with some variations. The project installed presented distribution uniformity coefficients (CUD) and statistical uniformity coefficient (CUE) with values ranging from good to excellent / O semiárido por apresentar condições climáticas desfavoráveis para agricultura, com déficit hídrico durante grande época do ano, chuvas mal distribuídas e altas temperaturas, necessita da irrigação para o desenvolvimento das culturas. Na ótica da agricultura sustentável, a irrigação localizada é o método de maior eficiência no uso da água, o que tem atraído os produtores rurais e as empresas agrícolas. Os sistemas de irrigação por gravidade em condutos fechados são os mais indicados para os produtores familiares, devido baixo custo e por operarem a baixas pressões. O presente trabalho teve como objetivo desenvolver um sistema de irrigação similar ao bubbler que permita aplicar água de forma localizada em plantas de cultivos em linhas e adensadas. Foram estabelecidas curvas de vazão-comprimento-carga hidráulica. Foi montado um modelo de dimensionamento para o sistema de irrigação, onde foram realizados testes de avanço em campo em diferentes solos, para estabelecer um modelo que relacione vazão-comprimento da bacia-tempo de irrigação e, por fim, a instalação do sistema de irrigação onde se avaliou a uniformidade da vazão na área. A instalação do sistema de irrigação foi realizada no município de Upanema/RN, em um Cambissolo de textura média, cultivado com palma forrageira, utilizando água de abastecimento. Em relação às curvas do teste de avanço da água no solo, pode-se dizer que as equações potenciais foram similares as equações logarítmicas. Recomenda-se o uso do modelo potencial para representar os dados da curva do teste de avanço de água no solo. As perdas de carga do protótipo praticamente não apresentaram variação e foram mínimas, já no projeto instalado este foi bastante expressivo e com algumas variações. O projeto instalado apresentou coeficientes de uniformidade de distribuição (CUD) e coeficientes de uniformidade estatístico (CUE) com valores variando de bom a excelente / 2017-01-31
2

Řídící jednotka pro aeroponický pěstební systém / Control unit for aeroponic growing system

Vrabec, Miroslav January 2013 (has links)
This thesis deals with the history of a method of plants cultivation without original substrate. The method is hydroponics and its subsequent development is called aeroponics. This work outlines the design of the whole aeroponic system including a control unit. The control unit has been designed to control the injection of nutrient solution, which is essential to the life of plants.Further, the control unit performs the control of lighting period, temperature, air flow and also regulation of nutrient solution pH. The control unit also keeps records of all data necessary for the monitoring process and for the evaluation of time differencies in the system.
3

Řídící jednotka pro aeroponický pěstební systém / Control unit for aeroponic growing system

Vrabec, Miroslav January 2013 (has links)
This thesis deals with the history of a method of plants cultivation without original substrate. The method is hydroponics and its subsequent development is called aeroponics. This work outlines the design of the whole aeroponic system including a control unit. The control unit has been designed to control the injection of nutrient solution, which is essential to the life of plants.Further, the control unit performs the control of lighting period, temperature, air flow and also regulation of nutrient solution pH. The control unit also keeps records of all data necessary for the monitoring process and for the evaluation of time differencies in the system.
4

Modely a analýzy v kontejnmentovém systému s potlačením tlaku při haváriích s únikem chladiva / Models and analysis of the pressure suppression system containment, during the loss of coolant accidents

Studýnka, Radim January 2014 (has links)
This diploma thesis deals with a pressure suppression system containment during the loss of coolant accidents. It is focused on the containment systems of the nuclear power plants with VVER-440/V-213 reactors. There is described the process of loss of coolant accident. There was designed input model which consists of the zones representing the areas which are connected with junctions and heat structures. Were then selected input parameters for the model calculations. And finally, there have been several calculations for the selected parameters.

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