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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

Padrões de resposta termal ao déficit hídrico na cultura do café irrigado por gotejamento / Standards of thermal response to drought in irrigated coffee crop drip

Costa, Jéfferson de Oliveira 08 July 2016 (has links)
O Brasil é destaque mundial na produção, na exportação e no consumo de café. Esta cultura ocupa cerca de dois milhões de hectares no território brasileiro, sendo plantada principalmente nos estados de MG, ES, SP e BA. A irrigação está presente em cerca de 10% da área plantada do cafeeiro arábica, já para o café robusta, este valor chega a 35%, o que torna o café uma das principais culturas irrigadas do Brasil. Porém, o déficit hídrico tornou-se o principal fator limitante da produção cafeeira, devido a expansão da cafeicultura para áreas consideradas marginais. A resposta do cafeeiro ao estresse hídrico pode ser avaliada utilizando-se medidas de potencial de água na folha no pré amanhecer, no entanto, essa metodologia restringe-se a atividades de pesquisa. O uso do CWSI (Crop Water Stress Index) calculado através da temperatura foliar como indicativo do potencial hídrico pode ser uma alternativa. O objetivo deste trabalho foi definir as relações entre o potencial de água na folha da cultura do café com o CWSI calculado através de medidas de temperatura com canhão infravermelho e com câmera térmica e analisar se estas relações apresentam bons índices de correlação, de precisão e de acurácia. O estudo foi realizado em um ambiente protegido localizado na área de pesquisa do Departamento de Engenharia de Biossistemas na Escola Superior de Agricultura \"Luiz de Queiroz\". A espécie plantada foi a Coffea arabica da variedade Catuaí Vermelho IAC 144, o sistema de irrigação adotado foi o gotejamento e o manejo foi feito por tensiometria. Utilizou-se o delineamento em blocos casualizados, sendo este formado por quatro blocos e quatro lâminas de irrigação (L130%, L100%, L70% e L40%) aplicadas em quatro épocas distintas (30/03 a 24/04, 07/06 a 02/07, 17/08 a 11/09 e 10/10 a 04/11) ao longo do ano de 2015. A unidade experimental foi representada por uma caixa com uma planta. Foram avaliadas a fração de radiação fotossinteticamente ativa interceptada, o potencial de água na folha e a temperatura foliar. A partir dos dados de temperatura foliar e dos dados meteorológicos calculouse o CWSI. As três variáveis avaliadas apresentaram relações significativas com os tratamentos impostos. O CWSI calculado para as diferentes situações e o potencial de água na folha apresentaram correlações bem representadas pelos modelos linear e cúbico. Os mesmos modelos apresentaram altos índices de precisão e acurácia. Conclui-se que o CWSI é um bom indicador do potencial hídrico da cultura do cafeeiro e pode substituir medidas do potencial de água na folha realizadas na câmara de Scholander. / Brazil is the world featured in production, export and consumption of coffee. This crop occupies about two million hectares in our country, it is mainly planted in state MG, ES, SP and BA. Irrigation is present in about 10% of the area planted arabica coffee, as for robusta coffee, this figure reaches 35%, which makes coffee one of the main irrigated crops in Brazil. But the drought has become the main limiting factor of coffee production due to the coffee growing expansion into areas considered marginal. The coffee response to water stress can be evaluated using water potential measurements on the sheet in the pre dawn, however, this methodology is limited to research activities. The use of CWSI (Crop Water Stress Index) calculated by leaf temperature as an indicator of water potential may be an alternative. The objective of this study was to define the relationship between the potential of water in the coffee culture of the sheet with the CWSI calculated from temperature measurements with infrared gun and thermal camera and analyze if these relations have good levels of correlation, accuracy and accuracy. The study was conducted in a protected environment located in the area of research in the Department of Biosystems Engineering at the School of Agriculture \"Luiz de Queiroz\". The planted species was the Coffea arabica variety Catuaí IAC 144, the adopted irrigation system was dripping and management was made by tensiometers. We used the randomized block design, which is made up of four blocks and four irrigation levels (L130%, L100%, L70% and L40%) applied in four different times (30/03 a 24/04, 07/06 a 02/07, 17/08 a 11/09 e 10/10 a 04/11) the 2015 year long. The unit experimental was represented by a box with a plant. We evaluated the intercepted photosynthetically active radiation fraction, water potential in the leaf and the leaf temperature. From the leaf temperature data and meteorological data we calculated the CWSI. The three variables evaluated showed significant relationships with tax treatments. The CWSI calculated for different situations and the potential of water in the sheet showed correlations well represented by linear and cubic models. The same models showed high precision and accuracy. It is concluded that the CWSI is a good indicator of water potential of the coffee crop and can replace water potential measurements on the sheet held in Scholander chamber.
2

Padrões de resposta termal ao déficit hídrico na cultura do café irrigado por gotejamento / Standards of thermal response to drought in irrigated coffee crop drip

Jéfferson de Oliveira Costa 08 July 2016 (has links)
O Brasil é destaque mundial na produção, na exportação e no consumo de café. Esta cultura ocupa cerca de dois milhões de hectares no território brasileiro, sendo plantada principalmente nos estados de MG, ES, SP e BA. A irrigação está presente em cerca de 10% da área plantada do cafeeiro arábica, já para o café robusta, este valor chega a 35%, o que torna o café uma das principais culturas irrigadas do Brasil. Porém, o déficit hídrico tornou-se o principal fator limitante da produção cafeeira, devido a expansão da cafeicultura para áreas consideradas marginais. A resposta do cafeeiro ao estresse hídrico pode ser avaliada utilizando-se medidas de potencial de água na folha no pré amanhecer, no entanto, essa metodologia restringe-se a atividades de pesquisa. O uso do CWSI (Crop Water Stress Index) calculado através da temperatura foliar como indicativo do potencial hídrico pode ser uma alternativa. O objetivo deste trabalho foi definir as relações entre o potencial de água na folha da cultura do café com o CWSI calculado através de medidas de temperatura com canhão infravermelho e com câmera térmica e analisar se estas relações apresentam bons índices de correlação, de precisão e de acurácia. O estudo foi realizado em um ambiente protegido localizado na área de pesquisa do Departamento de Engenharia de Biossistemas na Escola Superior de Agricultura \"Luiz de Queiroz\". A espécie plantada foi a Coffea arabica da variedade Catuaí Vermelho IAC 144, o sistema de irrigação adotado foi o gotejamento e o manejo foi feito por tensiometria. Utilizou-se o delineamento em blocos casualizados, sendo este formado por quatro blocos e quatro lâminas de irrigação (L130%, L100%, L70% e L40%) aplicadas em quatro épocas distintas (30/03 a 24/04, 07/06 a 02/07, 17/08 a 11/09 e 10/10 a 04/11) ao longo do ano de 2015. A unidade experimental foi representada por uma caixa com uma planta. Foram avaliadas a fração de radiação fotossinteticamente ativa interceptada, o potencial de água na folha e a temperatura foliar. A partir dos dados de temperatura foliar e dos dados meteorológicos calculouse o CWSI. As três variáveis avaliadas apresentaram relações significativas com os tratamentos impostos. O CWSI calculado para as diferentes situações e o potencial de água na folha apresentaram correlações bem representadas pelos modelos linear e cúbico. Os mesmos modelos apresentaram altos índices de precisão e acurácia. Conclui-se que o CWSI é um bom indicador do potencial hídrico da cultura do cafeeiro e pode substituir medidas do potencial de água na folha realizadas na câmara de Scholander. / Brazil is the world featured in production, export and consumption of coffee. This crop occupies about two million hectares in our country, it is mainly planted in state MG, ES, SP and BA. Irrigation is present in about 10% of the area planted arabica coffee, as for robusta coffee, this figure reaches 35%, which makes coffee one of the main irrigated crops in Brazil. But the drought has become the main limiting factor of coffee production due to the coffee growing expansion into areas considered marginal. The coffee response to water stress can be evaluated using water potential measurements on the sheet in the pre dawn, however, this methodology is limited to research activities. The use of CWSI (Crop Water Stress Index) calculated by leaf temperature as an indicator of water potential may be an alternative. The objective of this study was to define the relationship between the potential of water in the coffee culture of the sheet with the CWSI calculated from temperature measurements with infrared gun and thermal camera and analyze if these relations have good levels of correlation, accuracy and accuracy. The study was conducted in a protected environment located in the area of research in the Department of Biosystems Engineering at the School of Agriculture \"Luiz de Queiroz\". The planted species was the Coffea arabica variety Catuaí IAC 144, the adopted irrigation system was dripping and management was made by tensiometers. We used the randomized block design, which is made up of four blocks and four irrigation levels (L130%, L100%, L70% and L40%) applied in four different times (30/03 a 24/04, 07/06 a 02/07, 17/08 a 11/09 e 10/10 a 04/11) the 2015 year long. The unit experimental was represented by a box with a plant. We evaluated the intercepted photosynthetically active radiation fraction, water potential in the leaf and the leaf temperature. From the leaf temperature data and meteorological data we calculated the CWSI. The three variables evaluated showed significant relationships with tax treatments. The CWSI calculated for different situations and the potential of water in the sheet showed correlations well represented by linear and cubic models. The same models showed high precision and accuracy. It is concluded that the CWSI is a good indicator of water potential of the coffee crop and can replace water potential measurements on the sheet held in Scholander chamber.
3

Thermal And Visible Band Image Fusion For Abandoned Object Detection

Yigit, Ahmet 01 February 2010 (has links) (PDF)
Packages that are left unattended in public spaces are a security concern and timely detection of these packages is important for prevention of potential threats. Operators should be always alert to detect abandoned items in crowded environments. However, it is very difficult for operators to stay concentrated for extended periods. Therefore, it is important to aid operators with automatic detection of abandoned items. Most of the methods in the literature define abandoned items as items newly added to the scene and stayed stationary for a predefined time. Hence other stationary objects, such as people sitting on a bench are also detected as suspicious objects resulting in a high number of false alarms. These false alarms could be prevented by discriminating suspicious items as living/nonliving objects. In this thesis, visible band and thermal band cameras are used together to analyze the interactions between humans and other objects. Thermal images help classification of objects using their heat signatures. This way, people and the objects they carry or left behind can be detected separately. Especially, it is aimed to detect abandoned items and discriminate living or nonliving objects
4

Technologické postupy pájení pouzder QFN / QFN Packages Soldering and Technology Procedures

Jakub, Miroslav January 2015 (has links)
This master´s thesis deals with QFN packages soldering and technology procedures optimization. The aim of theoretical part is description of QFN packages, their assembly and reflow soldering on PCB in HONEYWELL. The aim of the practical part is to propose a method of measuring temperature and optimizing the thermal profiles of selected PCB with QFN packages by using convection (HONEYWELL) and infrared (BUT) reflow ovens. Comparison and evaluation of thermal profiles for 3 production PCBś with QFN packages using solder paste AIM NC257-2 were realised. The main part of master´s thesis are appearance evaluation of solder joints, preparing microsection and measuring intermetallic layers thickness by using the optical and the scanning electron microscopes, analysation and study of QFN defects created during soldering proces. These tests were performed with 2 production PCB´s. Optimization of SPI and soldering technology procedures where were analyzed QFN packages were processed on one type of PCB. Interesting part of this diplomma thesis is creating of the 3D heat transfer model of QFN package during the reflow soldering in SolidWorks.

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