Programa de Pós-Graduação em Engenharia de Processos - PPGEP/ITEC
URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/10052
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Navegando Programa de Pós-Graduação em Engenharia de Processos - PPGEP/ITEC por Orientadores "REIS, Marcos Allan Leite dos"
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Item Acesso aberto (Open Access) Desenvolvimento de termocélulas nanoestruturadas do tipo em camadas e coplanar(Universidade Federal do Pará, 2021-08-10) PINHEIRO, Paula Fabíola Pantoja; REIS, Marcos Allan Leite dos; http://lattes.cnpq.br/8252507933374637; https://orcid.org/0000-0003-2226-2653Environmental problems accentuated by fires and fossil fuels reflect the need to develop more accurate environmental monitoring systems, as well as the reuse of waste heat in thermoelectric conversion in industrial processes. Thus, in this research, thermocells based on Buckypaper (BP) were developed in two arrangements: layered and coplanar. BP was produced by vacuum filtration of functionalized Carbon Nanotubes (f-CNTs) through a filter paper with 14 μm pores. Scanning Electron Microscopy showed a BP consisting of cellulose fibers impregnated with agglomerated f-CNTs. By measuring two-point, a BP tape (1.0 cm2) showed an electrical resistance of 0.92 kΩ at 300 K. When heated in the range of 300-337 K, the BP reduced on average 22.39% of its electrical resistance, characterized as a thermoresistor. In the layered thermocell, keeping the copper electrode at room temperature while the BP electrode (active area: 5.5 cm2 ) was thermally excited generated a thermoelectric power (α) of 26.33 mV/K for ΔT = 3.0 K. This result is superior to that reported in nanostructured thermoelectrochemical cells and is close to that obtained by commercial silicon. In the coplanar thermocell, the BP was connected between two copper electrodes that acted as hot and cold sides (cooled by a heatsink) and reached α = -0.06 mV/K for ΔT = 19 K. This result was inferior to that obtained for Bi2Te3 and superior to that obtained by a free-standing BP based on nitrogen-doped CNTs.Item Acesso aberto (Open Access) Prototipagem de sistema de alarme de incêndio baseado em sensor nanoestruturado integrado a IoT(Universidade Federal do Pará, 2021-06-29) FREITAS, Luís Gustavo Oliveira de; REIS, Marcos Allan Leite dos; http://lattes.cnpq.br/8252507933374637The improvement of remote sensing systems for the detection of forest fires or industrial plants is fundamental to the development of industry 4.0, and it is becoming increasingly important for many countries where forest fires occur frequently. Therefore, it is necessary to design and explore a device that has a quick response, that has remote monitoring in real time and can generate warning signs that precede major fires in indoor (indoor) and outdoor (outdoor) environments, this nanostructured sensor based on buckypaper that it consists of carbon nanotube films and has thermal sensitivities that can be measured in short response times. In the prototyping of the fire alert sensor, thermal tests were carried out to evaluate the effectiveness. Furthermore, it was integrated with IoT (Internet of Things) using the NodeMCU architecture together with the MQTT (Message Queuing Telemetry Transport) protocol, thus enabling the sending of the alert message to the end user through an Android application. Preliminary results show that this nanostructured sensor can be effective at distances of less than 1 meter from the fire source, for example at 20 cm, generating a thermovoltage of 2.3 mV over 80 seconds with a heat source at 240 ° C. This work shows the entire development process of this prototype with real-time monitoring with the function of issuing an early fire alert.