Gas Sensors
Mostrando 13-24 de 53 artigos, teses e dissertações.
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13. Sensor de impedâncias de anéis para medida de fração de vazio em escoamento gás-líquido / Ring impedance sensor for void fraction gas-liquid meter
É proposta uma metodologia de projeto e de calibração de um medidor de fração de vazio para escoamento de gás e líquido operando com o princípio de impedâncias elétricas baseado em simulação numérica. O desenvolvimento do sensor é feito utilizando-se de um software de volumes finitos para a otimização heurística da geometria dos eletrodos e
Publicado em: 2011
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14. Experimental investigation of horizontal gas-liquid slug flow by means of wire-mesh sensor
The monitoring and visualization of two-phase flow is of great importance either from technical/practical point of view for process control and supervision or from scientific/theoretical point of view, for the understanding of physical phenomenon. A wire-mesh sensor was applied to experimentally investigate two-phase horizontal pipe flow. Furthermore, some p
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2011
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15. Identificação de plásticos comerciais por meio de um nariz eletrônico baseado em polímeros condutores. / Identification of plastics commercials through an electronic nose based on conducting polymers.
O presente trabalho consiste no desenvolvimento de uma nova técnica de identificação de materiais poliméricos por meio do uso de um nariz eletrônico. Narizes eletrônicos têm sido desenvolvidos para detecção automática e classificação de odores e gases. São instrumentos capazes de medir a concentração ou intensidade odorante de modo similar a u
Publicado em: 2011
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16. Síntese e caracterização de derivados do politiofeno para utilização em sensores / Synthesis and characterization of polythiophene derivatives and their use in VOCs sensor applications
The conjugated polymers, especially polythiophenes, have emerged as alternative materials to obtain chemically selective layers in gas sensors. The main advantages of these materials are the possibility of obtaining sensing devices that operate at room temperature and the diversity of materials. For example, a simple modification of the side chain of polythi
Publicado em: 2010
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17. Síntese e aplicação de polímeros condutores em sensores olfativos / Synthesis and application of conductive polymers in olfactory sensors
Os objetivos do trabalho consistem em síntese e caracterização de três polímeros: poli(2,1,3-benzotiadiazol-4,7-ilenovinileno) (PBTDV), poli(2,1,3-benzotiadiazol-4,7-ilenovinileno-co-2-bromo-5-hexilóxi-p-fenilenovinileno (PBTDV-co-BHPPV) e poli(2-bromo-5-hexilóxi-p-fenilenovinileno) (BHPPV), sendo os dois primeiros inéditos; aplicação de polímeros
Publicado em: 2010
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18. Estudo de materiais piezoelétricos da família III-V obtidos por sputtering reativo visando sua aplicação em sensores e MEMS. / Study of III-V piezoelectric materials obtained by reactive sputtering for sensors and MEMS applications.
Neste trabalho, apresento um estudo sobre a fabricação e caracterização físico-química de filmes finos de nitreto de alumínio (AlN) obtidos pela técnica de pulverização catódica reativa por rádio frequência (r.f sputtering) utilizando um alvo de alumínio puro. Visto que o AlN é um material que apresenta piezoeletricidade e compatibilidade com
Publicado em: 2010
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19. Corrosão anisotropica e formação de superficie nanoestruturada de Si utilizando plasma de alta densidade / Si anisotropic etching and nanostructured surface formation using high density plasma
This work explores the implementation, characterization and applications of BOSCH type process for bulk silicon etching (or bulk silicon micromachining) using inductively coupled high density plasma (ICP). This etching process is characterized by its high anisotropy and is performed by alternating etching steps, employing SF6 + Ar gas mixture, and passivatio
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 29/07/2009
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20. Effect of initialization time on application potentiality of a ZnO thin film based LPG sensor
A prototype electronic LPG (Liquid Petroleum Gas) sensor based on zinc oxide (ZnO) film has been fabricated. The objective of the present work was to investigate the importance of initialization time (also called warm-up time) on the application potentiality of the ZnO based alarm. The role of sensor geometry on initialization time is presented. The electron
Materials Research. Publicado em: 2009-09
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21. Influence of drying on the characteristics of zinc oxide nanoparticles
The recent growth in the field of porous and nanometric materials prepared by non-conventional processes has stimulated the search of new applications of ZnO nanoparticulate. Zinc oxide is an interesting semiconductor material due to its application on solar cells, gas sensors, ceramics, catalysts, cosmetics and varistors. In this work, the precipitation met
Brazilian Journal of Physics. Publicado em: 2009-04
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22. Grain size effect on the electrical response of SnO2 thin and thick film gas sensors
Porous nano and micro crystalline tin oxide films were deposited by RF Magnetron Sputtering and doctor blade techniques, respectively. Electrical resistance and impedance spectroscopy measurements, as a function of temperature and atmosphere, were performed in order to determine the influence of the microstructure and working conditions over the electrical r
Materials Research. Publicado em: 2009-03
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23. Sensor de NO2 utilizando-se filmes moleculares de macrociclos de porfirinas
The object of this work is the study, characterization and development of new sensors using the LB and LS of thin films deposition techiniques. Such sensors has been used for the gas sensing of NO2, althought, not discarting its use for detecting other gases or substances such as alchools or herbicides, etc. The materials used for assemble the sensors were t
Publicado em: 2009
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24. Nanotubos de titanatos aplicados como sensores de gás
In this work, the application of titanate nanotubes (TNTs) as gas sensors is investigated. TNTs were synthesized by refluxing a TiO2 (anatase) suspension in an aqueous NaOH (10 M) solution for 24hr, followed by washing with water until neutralization. Characterization by X-ray diffraction and scanning and transmission electron microscopies revealed that the
Publicado em: 2009