Optical strain gauge with high spatial resolution

A technique to enhance the spatial resolution of typical fiber Bragg grating–based strain gauges has been experimentally verified in this study. Just analyzing the intensity of the reflection spectrum of a sampled fiber Bragg grating, its inner deformation profile has been obtained with a spatial resolution of Formula L<1mm. The proposed method employs a synthesis algorithm to retrieve the longitudinal axis strain profile of a sampled fiber Bragg grating glued to an asymmetric plate. The achieved experimental results have been compared to the mechanical simulations of the employed plate, exhibiting a good response even without compensating the residual stress provoked during the installation process.This study was supported by the project TEC2010-20224-C02-02 and grant AP2009-1403

Recovering a fiber Bragg grating axial strain distribution from its reflection spectrum

A processing scheme able to obtain any arbitrary intragrating strain distribution of a fiber Bragg grating (FBG) is proposed and demonstrated. The processing method employs just the intensity of the FBG reflection spectrum to obtain its deformation profile by combining a geometrical processing scheme with the particle swarm optimization technique. The technique has been evaluated using several spectra generated from very heterogeneous strain distributions and with a real spectrum obtained from a 5 mm length FBG under an asymmetric perturbation. The achieved results exhibit a good spatial resolution (Δ≈0.5 mm) and repeatability.This work has been supported by the project TEC2010-20224-C02-02 and grant AP2009-140

Incidencia de RINACE en el desarrollo de la investigación sobre eficacia escolar en América Latina

Las tecnologías de la información y la comunicación son una importante vía de apropiación social del conocimiento del que pueden beneficiarse los países que han llegado tardíamente al proceso investigativo, a la vez que permiten la consolidación de comunidades científicas constituidas por componentes de diferente procedencia y formación específica. En este sentido, y como elemento que ha favorecido la difusión de la investigación sobre Eficacia Escolar en América Latina, se presenta la Red Iberoamericana de Investigación Sobre Cambio y Eficacia Escolar (RINACE), que con diez años de creación, setecientos miembros dediecinueve redes nacionales ha permitido fomentar la realización de investigaciones educativas de calidad, potenciar la difusión de las investigaciones realizadas, impulsar la utilización de los resultados de la investigación para la mejora de los sistemas educativos, las escuelas y las aulas y formar investigadores iberoamericanos de alto nivel sobre estas temática

Real options of distributed DAS sensing applied to road transport engineering

Distributed Acoustic Sensing (DAS) techniques with Optical Fibers are able to provide a wide range of data for very long distances. The technique is used for monitoring purposes on the energy sector (i.e.: oil &gas pipes, electricity transport lines, etc..), where the resiliency of the infrastructure linear layout is low, and the associated loss-of-service costs are high. The significant cost barriers of the technology are changing due to the scientific advances and the economy of scale effects; however, the use within the road transport engineering is still not widespread and limited to specific applications. This work explores the cost-benefit analysis of using the DAS technique for transport engineering, including a sensitivity analysis on the foreseeable cost reductions and technical characteristics of the technology applied to planning, operation and maintenance purposes. The real options of installing new fiber optic layout vs using dark fiber networks is also analysed and compared to the use of standard ITS systems.We thank the support of PID2019-107270RB-C21 (funded by MCIN/ AEI/ 10.13039/501100011033) and PDC2021-121172-C22 funded by MCIN/AEI /10.13039 /501100011033 and European Union Next Generation EU/PRTR. Our sincere gratitude Alayn Loayssa (Public University of Navarra), Victor Centeno (WSP) and to William Fawcett, Ian Ellinghan, Martin Hughes, Lars Mikalsen and the CILECCTA project (FP7-NMP 229061) for the LCC and Real Options methodology

Smart material using fiber Bragg grating transducers and shape memory alloy actuators

A structure based on a smart material and a PID control loop is presented in this paper. A glass fiber reinforced plastic material is instrumented with Fiber Bragg Gratings (FBG) and Shape Memory Alloy (SMA) actuators. The smart material and the smart structure are both successfully checked by being subjected to different operational conditions at the laboratory. Very good responses are obtained under both slow and quicker varying conditions.This work has been supported by the Spanish TEC2010-20224-C02-02 project and grant AP2009-140

Radial processing scheme of speckle patterns for sensing applications

A processing scheme to enhance the speckle sensitivity to dynamic perturbation has been proposed and tested. Considering different areas within speckle patterns where highest order modes interfere, a better dynamic sensitivity has been achieved.This work has been supported by the Spanish Government through CYCIT projects DA2TOI (FIS2010-19860), TFS (TEC2010-20224-C02-02) and the Alma’s Eguizabal PhD Grant (FPU12/04130

Focal beam position detection in a laser induced breakdown spectroscopy system by using a fiber Bragg grating sensor

Chemical analysis of dangerous materials entails a safety issue for the researchers. Laser Induced Breakdown Spectroscopy offers the possibility to analyze these materials away from them using Stand-Off Set-ups. To optimize the plasma induction, the remote focalization of the laser beam is of paramount importance. A custom Fiber Bragg Grating sensor system able to correct the laser beam focalization errors is proposed and experimentally checked. The optical transducer architecture and the preliminary obtained results are reported in this paper.This work has been co-supported by the Spanish Government through the project TEC2010-20224-C02- 02 and the grant AP2007-02230

Laser-induced breakdown spectroscopy: fundamentals, applications, and challenges

Laser-induced breakdown spectroscopy (LIBS) is a technique that provides an accurate in situ quantitative chemical analysis and, thanks to the developments in new spectral processing algorithms in the last decade, has achieved a promising performance as a quantitative chemical analyzer at the atomic level. These possibilities along with the fact that little or no sample preparation is necessary have expanded the application fields of LIBS. In this paper, we review the state of the art of this technique, its fundamentals, algorithms for quantitative analysis or sample classification, future challenges, and new application fields where LIBS can solve real problems

A fuzzy multicriteria approach for IT Governance evaluation

This work seeks to provide a new multi-criteria approach to assess IT Governance (ITG) in the area of Strategic Alignment. The complete methodological development process is described. The evaluation model uses Fuzzy Analytic Hierarchy Process (FAHP) and it is targeted to IT processes, more specifically to the COBIT© IT maturity levels, domains and processes, thus providing a differentiated analysis of importance for each item. Its relevance is related to addressing isolated and individual evaluation criteria that are normally practiced in audits of processes. The model allows generating information that extends the guarantees of compliance and corporate governance from different organizations. This research demonstrates that the combined use of multi-criteria decision methodologies and soft computing proves to be particularly suitable for Strategic Alignment such as the focal area of COBIT. The model was applied in a big retail Brazilian company

Fiber Bragg Grating sensors for on-line welding diagnostics

In this work Fiber Bragg Grating transducers (FBGs) are used to perform an on-line monitoring of an arc-welding process by means of the combined temperature and strain profile. The main goal of this approach is to establish a correlation between the appearance of defects in the seams and the response offered by the FBGs, exploring the optimal disposition of the FBGs in terms of their sensitivity to weld defects. The proposed solution will be explored by means of welding tests and a comparison with a plasma spectroscopic analysis.This work has been supported by the project TEC2010-20224-C02-02 and grant AP2009-1403. Authors would also like to thank Roberto Perez Sierra for his valuable help during the FBGs fabrication process