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Publications

2015

Fiber Optic Sensing System for Temperature and Gas Monitoring in Coal Waste Pile Combustion Environments

Authors
Viveiros, D; Ribeiro, J; Ferreira, J; Lopez Aldaba, A; Pinto, AMR; Perez Herrera, RA; Diaz, S; Lopez Gil, A; Dominguez Lopez, A; Esteban, O; Martin Lopez, S; Auguste, JL; Jamier, R; Rougier, S; Silva, SO; Frazao, O; Santos, JL; Flores, D; Roy, P; Gonzalez Herraez, M; Lopez Amo, M; Baptista, JM;

Publication
24TH INTERNATIONAL CONFERENCE ON OPTICAL FIBRE SENSORS

Abstract
It is presented an optical fiber sensing system projected to operate in the demanding conditions associated with coal waste piles in combustion. Distributed temperature measurement and spot gas sensing are requirements for such a system. A field prototype has been installed and is continuously gathering data, which will input a geological model of the coal waste piles in combustion aiming to understand their dynamics and evolution. Results are presented on distributed temperature and ammonia measurement, being noticed any significant methane emission in the short time period considered. Carbon dioxide is also a targeted gas for measurement, with validated results available soon. The assessment of this technology as an effective and reliable tool to address the problem of monitoring coal waste piles in combustion opens the possibility of its widespread application in view of the worldwide presence of coal related fires.

2015

Measuring strain at extreme temperatures with a Fabry-Perot optical fiber sensor

Authors
Ferreira, MS; Roriz, P; Bierlich, J; Kobelke, J; Wondraczek, K; Aichele, C; Schuster, K; Santos, JL; Frazao, O;

Publication
24TH INTERNATIONAL CONFERENCE ON OPTICAL FIBRE SENSORS

Abstract
In this work, a Fabry-Perot optical fiber sensor for the measurement of strain at extreme temperatures is proposed. The cavity is formed by splicing a short section of a silica tube between two sections of single mode fiber. The tube, with a cladding similar to 14 mu m thick and a hollow core, presents four small rods, of similar to 20 mu m in diameter each, positioned in in diametrically opposite positions. This design ensures higher mechanical stability of the tube. Strain measurements are performed over a wide range of temperatures, until 900 degrees C. Some of the annealing effects are addressed in this study.

2015

Fuzzy Control of a Water Pump for an Agricultural Plant Growth System

Authors
Dias, J; Coelho, JP; Gonçalves, JA;

Publication
Proceedings of the 7th International Joint Conference on Computational Intelligence (IJCCI 2015) - Volume 2: FCTA, Lisbon, Portugal, November 12-14, 2015.

Abstract
At the present time there is a high prebure toward the improvement of all the production procebes. Those improvements can be sensed in several directions in particular those that involve energy efficiency. The definition of tight energy efficiency improvement policies is transversal to several operational areas ranging from industry to public services. As can be expected, agricultural procebes are not immune to this tendency. This statement takes more severe contours when dealing with indoor productions where it is required to artificially control the climate inside the building or a partial growing zone. Regarding the latter, this paper presents an innovative system that improves energy efficiency of a trees growing platform. This new system requires the control of both a water pump and a gas heating system based on information provided by an array of sensors. In order to do this, a multi-input, multi-output regulator was implemented by means of a Fuzzy logic control strategy. Presented results show that it is pobible to simultaneously keep track of the desired growing temperature set-point while maintaining actuators streb within an acceptable range. © Copyright 2015 by SCITEPRESS - Science and Technology Publications, Lda.

2015

Incorporating regulator requirements in reliability analysis of smart grids. Part 1: Input data and models

Authors
Ridzuan M.I.M.; Hernando-Gil I.; Djokic S.; Langella R.; Testa A.;

Publication
IEEE PES Innovative Smart Grid Technologies Conference Europe

Abstract
This paper is part one of a two-part series discussing how Regulator requirements for continuity of supply could be incorporated in the reliability analysis of existing electricity networks and future 'smart grids'. The paper uses examples of overall and guaranteed standards of performance from the UK and Italy, specifying requirements that network operators should satisfy with respect to excessively long and/or too frequent supply interruptions. Besides the relevant Regulator requirements, this paper presents input data, parameters and models required for comprehensive reliability assessment, while Part 2 paper presents scenarios and results for test network based on both analytical and probabilistic reliability procedures.

2015

Wind farm distribution network optimization

Authors
Cerveira, A; Baptista, J; Pires, EJS;

Publication
INTEGRATED COMPUTER-AIDED ENGINEERING

Abstract
Wind energy production have been increasing in last years, with an annual growth of the installed capacity rate about 20%. It becomes important to develop optimization techniques to improve the effectiveness of the wind farms. One field in which this can be done is in the distribution network design that interconnects the turbines and the substation. This paper proposes two mathematical models to obtain the optimal electrical interconnection configuration of the wind farm turbines, considering technical constraints. One model minimizes the installation costs and the other one minimizes the installation costs and the energy losses costs registered during the wind farm lifetime. This problem corresponds to a capacitated minimum spanning tree with additional constraints. The proposed models were applied in two real wind farms. A sensitivity analysis is performed over two electrical parameters, the power factor and the load factor. The results show that the electrical losses of the wind farm must be taken into account in the optimization process.

2015

Measuring and teaching light spectrum using Tracker as a spectrometer

Authors
Rodrigues, M; Marques, MB; Simeao Carvalho, PS;

Publication
EDUCATION AND TRAINING IN OPTICS AND PHOTONICS: ETOP 2015

Abstract
In this work we present a simple and low cost setup that allows obtaining the light spectra and measuring the wavelength of its features. It is based on a cheap transmission diffraction grating, an ordinary digital camera and using Tracker software to increase measuring accuracy. This equipment can easily be found in most schools. The experimental setup is easy to implement (the typical setup for a pocket spectroscope) replacing the eye with the camera. The calibration is done using a light source with a well-known spectrum. The acquired images are analyzed with Tracker (freeware software frequently used for motion studies). With this system, we have analyzed several light sources. As an example, the analysis of the spectra obtained with compact fluorescent lamp allowed to recognize the spectrum of mercury in the lamp, as expected. This spectral analysis is therefore useful in schools, among other topics, to enable the recognition of chemical elements through spectroscopy, and to alert students to the different spectra of illuminating light sources used in houses and public places.

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