No description available.

A questão ambiental atualmente tem gerado grandes discussões sobre energias renováveis sendo que uma das grandes fontes é o sol. Porém, o aproveitamento da sua energia luminosa ainda não tem sido feito em larga escala em países que possuem essa disponibilidade, como é o caso do Brasil. Um dos motivos pode ser a falta de uma maior compreensão de como fazer o dimensionamento da iluminação natural. Este trabalho propõe o desenvolvimento de um sistema de medição desta iluminação natural, através de sensores de baixo custo adaptados para a função de medição, além de um equipamento de medidas e armazenagem de dados, bem um programa computacional que permita a descarga, gravação e interpretação desses dados em um computador. Através deste sistema poderá ser analisada a disponibilidade de luz natural externa, assim como a sua distribuição em espaços construídos simultaneamente. / The environmental issue has now created major discussions on renewable energy, being one of the major sources is the sun. However, the exploitation of its energy light has not yet been done on a large scale in countries that have such availability, such as Brazil. One reason may be the lack of a better understanding of how to make scaling of natural light. This paper proposes the development of a system of measurement of daylight, through low-cost sensors adapted for the task of measuring, and an equipment measures and storage of data, and a software that allows the discharge, recording and interpretation such data in a computer. Through this system could be considered the availability of external daylight, as well as their distribution in space constructed simultaneously.

A questão ambiental atualmente tem gerado grandes discussões sobre energias renováveis sendo que uma das grandes fontes é o sol. Porém, o aproveitamento da sua energia luminosa ainda não tem sido feito em larga escala em países que possuem essa disponibilidade, como é o caso do Brasil. Um dos motivos pode ser a falta de uma maior compreensão de como fazer o dimensionamento da iluminação natural. Este trabalho propõe o desenvolvimento de um sistema de medição desta iluminação natural, através de sensores de baixo custo adaptados para a função de medição, além de um equipamento de medidas e armazenagem de dados, bem um programa computacional que permita a descarga, gravação e interpretação desses dados em um computador. Através deste sistema poderá ser analisada a disponibilidade de luz natural externa, assim como a sua distribuição em espaços construídos simultaneamente. / The environmental issue has now created major discussions on renewable energy, being one of the major sources is the sun. However, the exploitation of its energy light has not yet been done on a large scale in countries that have such availability, such as Brazil. One reason may be the lack of a better understanding of how to make scaling of natural light. This paper proposes the development of a system of measurement of daylight, through low-cost sensors adapted for the task of measuring, and an equipment measures and storage of data, and a software that allows the discharge, recording and interpretation such data in a computer. Through this system could be considered the availability of external daylight, as well as their distribution in space constructed simultaneously.

No description available.

No description available.

Anthropogenic activity has caused increased concentrations of greenhouse gases (GHGs) in the atmosphere which has resulted in global warming gaining momentum. GHG emission estimates up to date are insufficient and in order to mitigate GHG emissions of anthropogenic origin fluxes of GHGs need to be mapped. The application of low-cost sensors (LCSs) as an environmental monitoring tool has been seen as a pathway with the ability to provide GHG estimates that can help us to identify sources and sinks. However, questions have been highlighted regarding the accuracy of LCSs in targeting GHGs in comparison to alternative environmental monitoring approaches. A network of LCSs with the ability to target carbon dioxide (CO2) and methane (CH4), among other environmental parameters of interest, were deployed at a wastewater treatment plant (WWTP) in Linköping, Sweden. A cross-checking procedure where LCS data were compared with data from high-precision measuring instruments UltraPortable Greenhouse Gas Analyser (UGGA) and air samples analysed with gas chromatography (GC), enabled evaluation of LCSs as an environmental monitoring tool. Despite uncertainties regarding individual sensors´ behaviour, results from this study show that LCS systems have the capability to bring valuable estimates of GHGs to the environmental monitoring field, although not yet at the precise level of reference equipment. The low cost of the LCS systems studied in this work open a range of possibilities because of their ability to provide large amounts of data on both a spatial and temporal scale that are not attainable for high-precision reference instruments. From the long-term measurements it can be concluded that the CO2 concentrations at the dewatered sludge deposit, and especially inside the screw conveyor building, are higher than global average levels of CO2. / Mänsklig aktivitet har orsakat ökade koncentrationer av växthusgaser i atmosfären vilket i sin tur har resulterat i att den globala uppvärmningen har accelererat. Estimeringar av växthusgasutsläpp har hittills varit bristfälliga och för att kunna lindra antropogena växthusgasutsläpp kartläggning av växthusgasers utbyten efterfrågas. Applicering av lågkostnads-sensorer som en ett verktyg inom miljöövervakning har setts som en möjlig väg i att tillhandahålla estimeringar av växthusgaser som kan hjälpa oss att identifiera källor och sänkor. Dock har frågor om hur precisa lågkostnads-sensorer är i jämförelse med alternativa miljöövervakningsmetoder lyfts. Ett nätverk av låg kostnads-sensorer som kan känna av koldioxid (CO2) and metan (CH4) och en rad andra miljömässiga parametrar av intresse, placerades ut på ett reningsverk i Linköping, Sverige. En procedur där sensordata ställdes mot data insamlad från de högprecisa instrumenten Ultra-Portable Greenhouse Gas Analyser och luftprover analyserande med gas kromatografi öppnade upp för möjligheten att utvärdera sensorernas prestanda. Trots osäkerheter i data gällande individuella sensorers beteende, så visar resultat från den här studien att låg kostnads-sensorsystem har kapaciteten att bidra med berikande estimeringar av växthusgaser till miljöövervakning området, dock ännu inte med samma precishet som för referensinstrument. Den låga kostnaden för lågkostnads-sensorsystemen som studeras i det här arbetet öppnar upp för en rad möjligheter tack vare att de kan tillhandahålla stora mängder data på både en spatial och temporal skala som inte är inom räckhåll för högprecisa referensinstrument. Från långtidsmätningarna kan det konstateras att koncentrationerna av CO2 vid slamavvattningslagret, och särskilt inne i skruvpressbyggnaden, är högre än det globala genomsnittsvärden för CO2 nivåer.

Existen muchos trabajos relacionados con el diseño y desarrollo de nodos sensores, donde se presentan gran variedad de aplicaciones. Las redes de sensores inalámbricos pueden facilitarnos y mejorar algunos aspectos de nuestra vida diaria. Es fácil, pensar que si este tipo de dispositivo es tan beneficioso para nosotros y para el entorno donde vivimos, su precio debería ser relativamente barato. Pero podemos comprobar que esto no es así. ¿Por qué estos dispositivos son tan caros? ¿Sería posible desarrollar dispositivos con las mismas capacidades y precios más económicos? ¿Cómo puedo fabricar mis nodos sensores de bajo coste? Esta tesis responde a estas preguntas y muestra algunas de las muchas aplicaciones que los nodos sensores pueden tener. En esta tesis hemos propuesto (e implementado en algunos casos) el desarrollo de nodos sensores para la monitorización del medio, a partir de dispositivos de bajo coste. Para la implementación de un nodo sensor, y en definitiva la red que une a todos estos nodos, es importante conocer el medio donde trabajarán. A lo largo de este documento se presentan las investigaciones llevadas a cabo para el desarrollo de sensores en tres ámbitos de aplicación. En el primero de ellos, se desarrollan dispositivos multisenores para la monitorización del medio. La aplicación de las redes de sensores inalámbricas al medio natural, precisa un estudio de cómo se ven afectadas las señales, en función de la distancia, vegetación, humedad del ambiente, etc. Focalizamos nuestros desarrollos en la verificación de incendios en zonas rurales y en el control de plagas en viñedos donde la detección precoz de estos eventos genera elevados ahorros económicos. También proponemos el desarrollo de una red de collares sensores para ganado domestico, que nos ayudará a reducir y prevenir en muchos casos, los ataques de lobos y hurtos de crías. Por último, dentro de este grupo, presentamos una red permite detectar anomalía de los materiales en edificios y red de sensores que nos permite monitorizar las personas mayores o deficientes, que se mueven junto con un grupo, en una excursión o actividad. El segundo grupo de aplicaciones, hace referencia a la monitorización de espacios en entornos de interior. Para ello hemos analizado el comportamiento de las señales inalámbricas en diferentes escenarios. Los resultados, nos han permitido extraer un nuevo método de diseño de las redes inalámbricas en interiores. Nuestro método, permite definir la mejor ubicación de los dispositivos de red y nodos sensores en interiores con un ahorro en el número de sensores del 15%. Por último, se presenta el estudio sobre las comunicaciones subacuáticas basadas en las ondas electromagnéticas donde analizamos la dependencia de las comunicaciones subacuáticas en agua dulce en función de la frecuencia, temperatura, tasas de transferencia de datos y modulación. Relacionado con el medio subacuático, presentamos 2 propuestas. La primera de ellas hace referencia a la implementación de una red de sensores para granjas marinas que nos permite reducir la cantidad de residuos depositados en el lecho marino y reducir el porcentaje de comida desperdiciada. La segunda propuesta es el desarrollo de dos sensores oceanográficos que nos permitirían controlar la cantidad de comida y heces depositadas en el suelo y controlar la turbidez del agua de manera muy simple y económica Todos estos desarrollos y propuestas, han estado precedidos por un exhaustivo estudio sobre los problemas energéticos que las redes de sensores inalámbricas presentan y las técnicas que pueden emplearse, para prolongar la vida útil de la red y mejorar su estabilidad. / There are many works related to the design and development of sensor nodes which present several applications. Wireless sensor networks can facilitate and improve some aspects of our daily lives. It is easy to think that if this type of device is so beneficial to us and to our environment, its price should be relatively cheap. But we can see that this is not true. Why these devices are so expensive? Would it be possible to develop devices with the same capabilities and lower prices? How can I make my low-cost sensor nodes? This dissertation answers these questions and shows some of the many applications that sensor nodes may have. In this dissertation, we propose (and implement in some cases) the development of sensor nodes for environmental monitoring, from low-cost devices. For the implementation of a sensor node and network which joins all these nodes, it is important to know the environment where they will work. Throughout this dissertation, we present the research carried out for the development of sensors in three main application areas. In the first of these areas, we present multisensor devices developed for environmental monitoring. The application of wireless sensor networks to the environment requires a study of how signals are affected depending on the distance, vegetation, ambient humidity, etc. We focus our developments on the fire detection in rural areas and on the control of pests in vineyards where the early detection of these events generates high economic savings. We also propose the development of a sensor network which will help us to reduce and prevent wolves¿ attacks and theft in livestock. Finally, within this group, we present a network to detect material anomalies in building and a sensor network which allows us to monitor the elderly or disabled people who move along with a group on a tour or activity. The second group of applications is related to the monitoring of spaces in indoor environments. For this, we analyze the behavior of wireless signals in different scenarios. These results allowed us to extract a new method for designing wireless networks in indoor environments. Our method allows defining the best location of network devices and sensor nodes indoors saving 15% of the sensors needed. Finally, we present a study on underwater freshwater communications based on electromagnetic waves, where we analyze the dependency of underwater communications as a function of working frequency, temperature, data transfer rates and modulation. Related to underwater environment, we present two proposals. First one refers to the implementation of a sensor network for marine farms which allows us to reduce the amount of waste deposited on the seabed and reduce the percentage of wasted food. The second proposal is the development of two oceanographic sensors which allow us to control the amount of food and feces deposited in seabed and the water turbidity control in a very simple and inexpensive way. All these developments and proposals have been preceded by a comprehensive study on the energy problems in wireless sensor networks. We have also presented several techniques which can be used to prolong the network lifetime and improve its stability. / Sendra Compte, S. (2013). Deployment of Efficient Wireless Sensor Nodes for Monitoring in Rural, Indoor and Underwater Environments [Tesis doctoral]. Editorial Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/32279 / Alfresco

The corrosion of steel reinforcement in reinforced concrete structures constitutes an alarming problem. To combat this problem, researchers at the University of Texas at Austin developed two, low-cost, passive, wireless sensors: a threshold, corrosion sensor and an analog conductivity sensor. Today, the basic circuit designs for both sensors are finished and their reliabilities are confirmed. However, multiple problems regarding the durability of the sensors remain. This research project: (a) identifies these problems, (b) proposes enhancements for each type of passive, wireless sensor, (c) tests and evaluates the proposed modifications to the sensors, and (d) proposes potential improvements and areas of research regarding the future development of these two sensors. / text

Submitted by Izabel Franco (izabel-franco@ufscar.br) on 2016-09-16T13:29:16Z No. of bitstreams: 1 TeseRKH.pdf: 7966483 bytes, checksum: 075f420f66971bcdd35c8dbfe1d3c37c (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-16T19:45:53Z (GMT) No. of bitstreams: 1 TeseRKH.pdf: 7966483 bytes, checksum: 075f420f66971bcdd35c8dbfe1d3c37c (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-16T19:45:58Z (GMT) No. of bitstreams: 1 TeseRKH.pdf: 7966483 bytes, checksum: 075f420f66971bcdd35c8dbfe1d3c37c (MD5) / Made available in DSpace on 2016-09-16T19:46:05Z (GMT). No. of bitstreams: 1 TeseRKH.pdf: 7966483 bytes, checksum: 075f420f66971bcdd35c8dbfe1d3c37c (MD5) Previous issue date: 2015-02-26 / Não recebi financiamento / The research proposal was found low cost alternative solution to automatize the classification and selection process to recognize fruit ripeness level using biologic behavior instead of human visual inspection. The goal was to develop low cost and disposable solid state sensor made of office paper with respective equipment for odor monitoring. The concept used to development this sensor was replace the interdigitated electrode with a conductive track using office paper impregnated with an electrolyte that "turns" cellulose fiber in an electrical conductor under gas action. In order to get gas adsorbing surface property for odor monitoring were tested some electrolytes like: Magnesium Chloride, Potassium Iodide, Calcium Hydroxide and others. This configuration replaced the interdigitated electrode per cellulose fiber doped with an electrolyte, it´s the originality of this research. In the fruit ripening process, the major enzymes involved are pectinase to crack the cell walls responsible for the fruits softening, amylase which degrades carbohydrates to simple sugars responsible for the flavor and hydrolase which reduces the amount of chlorophyll responsible for the fruit color change. The reaction that produces ethylene gas (C2H4) is lipids oxidation, the main gas exhaled during the fruits ripening process. The equipment adopted to pick up electrical signal is based on resistance and capacitance measuring that showed reversible electrical signal variation basically due the track geometry and cellulose fiber doping with an electrolyte. Another feature found was the office paper sensor decrease resistivity with fruit odors presence. The sensor manufacturing process is simple, basically consist in printing a mask with a negative image of the track by laser printing and office paper impregnation by an electrolyte. / A proposta da pesquisa foi buscar uma alternativa de baixo custo para automatizar o processo de seleção e classificação do nível de maturação da banana, utilizando-se do reconhecimento de gás exalado no processo de maturação via biológica, em vez da inspeção visual humana. O objeto da pesquisa foi desenvolver um sensor de estado sólido, de baixo custo e descartável, à base de papel sulfite, com o seu respectivo equipamento de monitoramento de odor. O conceito utilizado no desenvolvimento do sensor foi eliminar o eletrodo condutor interdigitado e substitui-lo por uma trilha condutora via dopagem do papel sulfite, impregnando com um eletrólito que “transforma” a fibra de celulose em um condutor elétrico sob a ação de gás. Visando conferir a propriedade de adsorção superficial dos gases no processo de monitoramento de odor, foram testados os seguintes eletrólitos: Cloreto de Magnésio, Iodeto de Potássio, Hidróxido de Cálcio entre outros. Essa configuração de substituir o eletrodo interdigitado por fibra de celulose dopada com um eletrólito traduz a originalidade desta pesquisa. No processo de amadurecimento das frutas, as principais enzimas envolvidas foram: pectinase, que quebra as paredes celulares, responsável pelo amolecimento das frutas; amilase, que degrada carboidratos em açúcares simples, responsável pelo sabor e a hidrolase, que reduz a quantidade de clorofila responsável pela mudança de cor da fruta. A reação que produz o gás etileno (C2H4) é a oxidação de lipídios, principal gás exalado durante o processo de amadurecimento das frutas. O equipamento de captação de sinal elétrico do sensor de estado sólido foi baseado na medição de resistência e capacitância, que apresentou variação de sinal elétrico reversível, basicamente em função da geometria da trilha e da dopagem da fibra de celulose com um eletrólito. Outra característica do sensor de papel sulfite foi a queda da resistividade com a presença de odores da fruta. O processo de fabricação do sensor é simples: consiste basicamente em uma impressão a laser de uma máscara com imagem negativa da trilha e a impregnação do papel sulfite com um eletrólito.