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10. Development of an Immunocapture-Based Polymeric Optical Fiber Sensor for Bacterial Detection in Water.

Author

Lopes, Rafaela Nascimento, Pinto, Paulo Henrique Silva, Vargas, Juan David Lopez, Dante, Alex, Macrae, Andrew, Allil, Regina Célia Barros, and Werneck, Marcelo Martins

Subjects
PLASTIC optical fibers, ESCHERICHIA coli, OPTICAL fiber detectors, OPTICAL fibers, OPTOELECTRONICS, CONFOCAL microscopy, PHOTODETECTORS
Abstract

Conventional methods for pathogen detection in water rely on time-consuming enrichment steps followed by biochemical identification strategies, which require assay times ranging from 24 hours to a week. However, in recent years, significant efforts have been made to develop biosensing technologies enabling rapid and close-to-real-time detection of waterborne pathogens. In previous studies, we developed a plastic optical fiber (POF) immunosensor using an optoelectronic configuration consisting of a U-Shape probe connected to an LED and a photodetector. Bacterial detection was evaluated with the immunosensor immersed in a bacterial suspension in water with a known concentration. Here, we report on the sensitivity of a new optoelectronic configuration consisting of two POF U-shaped probes, one as the reference and the other as the immunosensor, for the detection of Escherichia coli. In addition, another methos of detection was tested where the sensors were calibrated in the air, before being immersed in a bacterial suspension and then read in the air. This modification improved sensor sensitivity and resulted in a faster detection time. After the immunocapture, the sensors were DAPI-stained and submitted to confocal microscopy. The histograms obtained confirmed that the responses of the immunosensors were due to the bacteria. This new sensor detected the presence of E. coli at 104 CFU/mL in less than 20 min. Currently, sub-20 min is faster than previous studies using fiber-optic based biosensors. We report on an inexpensive and faster detection technology when compared with conventional methods. [ABSTRACT FROM AUTHOR]

Published
2024
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20. Uma nova técnica para caracterização de grades de Bragg em fibra óptica utilizando um método de deconvolução

Author

Dante, Alex, 1979, Ferreira, Elnatan Chagas, 1955, Leite, Rogerio Lara, Dias, Jose Antonio Siqueira, Universidade Estadual de Campinas. Faculdade de Engenharia Elétrica e de Computação, Programa de Pós-Graduação em Engenharia Elétrica, and UNIVERSIDADE ESTADUAL DE CAMPINAS

Subjects
Optical detectors, Electronics - Digital Instruments, Microelectronics, Eletrônica - Instrumentos digitais, Detectores óticos, Optoelectronics, Optoeletrônica, Microeletrônica
Abstract

Orientador: Elnatan Chagas Ferreira Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação Resumo: Sensores a fibra óptica utilizando grades de Bragg em fibra (fiber Bragg grating - FBG) estão se tornando cada dia mais importantes, dada a quantidade de aplicações nas quais vêm sendo empregados. Algumas das principais características dos sensores a FBG são: imunidade à interferência eletromagnética (EMI), isolamento elétrico, baixo peso, flexibilidade, e transmissão de informações a longa distância. Eles estão sendo empregados na medida de temperatura, deformação, carga, tensão mecânica e vibração. Estão presentes também em estruturas inteligentes, onde sensores a FBG distribuídos são incorporados à estrutura, permitindo a monitoração em tempo real das condições estruturais de pontes, trilhos ferroviários e aviões. Este trabalho apresenta uma nova técnica de caracterização de FBGs utilizando deconvolução. Nesta técnica, utiliza-se uma FBG sintonizável, cujo perfil de reflexão é bem conhecido, para caracterização de outra FBG, cujo perfil é inicialmente desconhecido. Utilizando placas eletrônicas com componentes de baixo custo, e um software desenvolvido em LabVIEW®, no qual implementamos a deconvolução dos perfis das FBGs, essa técnica permite o levantamento do perfil de reflexão e outros parâmetros, como a largura espectral FWHM (do inglês Full Width at Half Maximum) e o comprimento de onda de Bragg 'lâmbda'B, de uma FBG. Os resultados obtidos tornaram possível a validação da técnica proposta e permitem concluir que ela é robusta e, com refinamentos matemáticos que podem ser implementados no processo de deconvolução, permite a construção de um caracterizador de FBGs preciso e de custo bem inferior a equipamentos disponíveis comercialmente Abstract: Optical fiber sensors using fiber Bragg gratings (FBG) are becoming increasingly important, given the amount of applications in which they are being used. Some of the most important characteristics of FBGs are: electromagnetic interference (EMI) immunity, light weight, flexibility, and long range information transmission. FBG sensors are being used in the measurement of temperature, deformation, load, strain and vibration. They are also being used in smart structures, where several distributed sensing FBGs are embedded in materials to allow for the real-time monitoring of the structural conditions of bridges, railroad tracks and airplanes. A new technique for the FBGs characterization using deconvolution is presented. In this technique, a tunable FBG, whose reflection spectrum is known, is used to discover another FBGs profile, which is previously unknown. Using low-cost electronic parts and software developed in LabVIEW, which performs the deconvolution of both FBGs spectra, this technique allows the measurement of the FBG reflection spectrum, its FWHM (Full Width at Half Maximum), and the Bragg center wavelength 'lambda'B. The obtained results enables to validate the proposed technique, allowing concluding that it is robust and, if numerical refinement is implemented, it will be possible to build a low-cost FBG characterization device, in comparison with other commercial devices used for this purpose Mestrado Eletrônica, Microeletrônica e Optoeletrônica Mestre em Engenharia Elétrica

Published
2021

33. Disconnect Switch Position Sensor Based on FBG

Author

Mok, Roberto Wu, primary, Silveira, Pedro, additional, Dante, Alex, additional, Vargas, Juan, additional, Trovao, Talitha, additional, Bellini, Renato, additional, Carvalho, Cesar, additional, Allil, Regina, additional, and Werneck, Marcelo, additional

Published
2019
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34. Educación ambiental y conciencia ambiental en estudiantes del 5to. grado de la Institución Educativa Secundaria Agroindustrial Paucartambo Pasco 2019

Author

Becerra Pozo, Dante Alex and Vera Samaniego, Efraín Teódulo

Subjects
Aprendizaje, Educación ambiental, Valores (educación)
Abstract

El trabajo de investigación tiene como propósito determinar la relación existe entre la educación ambiental y conciencia ambiental en estudiantes del 5to. Grado de la Institución Educativa Secundaria Agroindustrial Paucartambo-Pasco, 2019, para lo cual se formuló el problema: ¿Qué relación existe entre la educación ambiental y conciencia ambiental en estudiantes del 5to. Grado de la Institución Educativa Secundaria Agroindustrial Paucartambo-Pasco, 2019? Para lo cual se formuló la hipótesis Existe relación directa entre la educación ambiental y conciencia ambiental en estudiantes del 5to. Grado de la Institución Educativa Secundaria Agroindustrial Paucartambo-Pasco, 2019. Al finalizar la investigación se llegó a la conclusión: Se determinó la relación entre la educación ambiental y conciencia ambiental en estudiantes del 5to. Grado de la Institución Educativa Secundaria Agroindustrial Paucartambo-Pasco, 2019, Luego de aplicar los instrumentos de investigación se tiene Rho de Spearman rho = 0.938, se tiene correlación muy alta, Además, siendo p= 0,000 y nivel de significancia es 0,05. Entonces 0,000 < 0,05, en consecuencia se corrobora la correlación. La investigación trata de una investigación de tipo básico y sustantiva, en la que se empleó el nivel descriptivo con diseño descriptivo correlacional de dos variables y una sola muestra. La población, estuvo constituida por 36 estudiantes de secundaria de la única Institución Educativa Agro Industrial Paucartambo; se aplicó un cuestionario de la variable 1 y luego otro cuestionario a la otra variable. Las mismas que pasaron pruebas de confiabilidad. Trujillo Escuela de Posgrado Calidad y Gestión Educativa

Published
2019

45. SOLAR TRACKER DEVELOPMENT BASED ON POFS AND FRESNEL LENS CONCENTRATION APPLIED TO MICROALGAE CULTIVATION ILLUMINATION.

Author

Allil, A. S., Rodrigues, I. V., Manchego, A. O. C., Werneck, A. M. S., Cruz, Y. R., Allil, R. C. S. B., Dante, Alex, de Carvalho, Cesar Cosenza, and Werneck, M. M.

Subjects
MICROALGAE, FRESNEL lenses, PLASTIC optical fibers, ENERGY consumption, PHOTOVOLTAIC power generation
Abstract

The solar lighting system was developed at Universidade Federal do Rio de Janeiro (LIF/COPPE/UFRJ). The objective of this project is to use solar energy over its light's form to improve a microalgae culture. In order to perform this scenario a brand new photobioreactor concept was developed then manufactured. The system works tracking the Sun from the sunrise till the sunset. It is composed by a Fresnel lens, which concentrates the solar beams into a plastic optical fiber (POF) bundle placed at the lens focus. [ABSTRACT FROM AUTHOR]

Published
2018

50. A Closed-Loop Interrogation Technique for Multi-Point Temperature Measurement Using Fiber Bragg Gratings.

Author

Dafico Pfrimer, Felipe Walter, Koyama, Marcela, Dante, Alex, Chagas Ferreira, Elnatan, and Siqueira Dias, Jose Antonio

Abstract

In this paper a closed-loop interrogation technique for multi-point temperature measurement using fiber Bragg gratings (FBG) is presented. The technique uses a broadband light source and n tunable FBGs to interrogate an array of n FBGs sensors placed along the optical fiber. Each center wavelength of the tunable FBGs is matched with the center wavelength of one FBG sensor placed in the array. The light source directly illuminates the sensor array, so that all the light reflected from the FBGs enters in the optical circuit through an optical circulator and the reflected spectrum of each sensing FBG illuminates a matched tunable FBG. Because the current generated by the photodiode is proportional to the convolution between the two FBGs profiles (the sensor FBG and the tunable FBG), by controlling the value of the convolution at a fixed value, the center wavelengths of the two FBGs are kept spaced by a constant value. Therefore, the temperature of the FBG sensor can be associated with the temperature of the tunable FBG. A two channel prototype was constructed to validate the technique and a very high resolution of ±0.001 °C was obtained. [ABSTRACT FROM PUBLISHER]

Published
2014
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