Abstract
A new type of fibre-optic refractive index sensor based on a long period fibre grating (LPFG) coated with a titanium dioxide (TiO2) thin film was demonstrated. The wavelength shift of the attenuation bands of this LPFG sensor to changes in the refractive index of the external media from 1.30 to 1.64 RIU was investigated. In order to optimize the sensor the TiO2 thin film thickness deposited around the LPFGs was varied from 10 to 80 nm. It was found that the TiO2 thin film increases the wavelength sensitivity of the LPFG to changes in the surrounding refractive index for values lower and higher than the cladding refractive index. As opposed to the bare LPFG it was shown the possibility to monitor refractive indices lower and higher than cladding refractive index tailoring the TiO2 thickness. An average wavelength sensitivity of 5250 nm/RIU was achieved in the range 1.444 to 1.456 RIU for a TiO2 thickness of 50 nm. In the region between 1.46 and 1.48 RIU the average sensitivity of about 825 nm/RIU was measured for a 40 nm thick film.

Abstract
Despite the socio-economic importance of mining in Douro Coalfield, the coal exploitation and utilization originated impacts on the environment. From these stands out the S. Pedro da Cova waste pile which is self-burning since 2005. The potential environmental impacts associated with this coal waste pile include: air pollution caused by the gaseous emissions and dispersion of solid particles; pollution of soils, surface and groundwater caused by mobilization of solid particles, leaching of hazardous elements, dissolution of neoformed and deposition of solid particles; landslides and mass movements also caused the weathering agents, and deterioration of vegetation that may also be due to the acid drainage. The main objective of this work is the combustion temperature monitoring in S. Pedro da Cova waste pile using the infrared thermography technique. The acquired results during the temperature monitoring campaigns allow the study of the dynamics and evolutionary scenarios of the self-burning process in the coal waste pile, contributing to a precise definition of the risks to the environment and human health. © 2014, LNEG – Laboratório Nacional de Geologia e Energia IP.

Abstract
A segment of a suspended-core microstructured fibre was dipped in a droplet of acetone and the evaporation dynamics of remaining acetone inside the cavity were simultaneously analysed with an optical microscope and an optical spectrum analyser. When the fibre is immersed it suffers a 14 dB signal drop. Different menisci form in each cladding cavity, with different evaporation times and rates. The signal restores its initial state not when the evaporation process is complete but after the collapse of a dominant meniscus.

Abstract
Interferometric fiber optic based sensors, namely those based on the Fabry-Perot (F-P) configuration seem very attractive for biomechanical and biomedical applications. The present study is focused on the proof of concept of two developed FP based sensors, for high and low pressure measurements of fluids. For low pressure sensor, it was used a polymeric diaphragm in a microstrutured fiber. It was obtained a good agreement between wavelength shift and the pressure, for the two tested sensors.

Abstract
A new configuration for volatile organic compound sensing is proposed. A sub-milimiter four-hole suspended core optical fiber tip, spliced to a standard single mode fiber, is dipped in a liquid volatile compound and the reflected signal is continuously interrogated. When the fiber is immersed in acetone it suffers a 1 4 dB signal drop. Different menisci form in each cladding cavity, with different evaporation times and rates. The signal restores its initial state not when the evaporation process is complete but after the collapse of a dominant meniscus.

Abstract
In vivo measurement, not only in animals but also in humans, is a demanding task and is the ultimate goal in experimental biomechanics. For that purpose, measurements in vivo must be performed, under physiological conditions, to obtain a database and contribute for the development of analytical models, used to describe human biomechanics. The knowledge and control of the mechanisms involved in biomechanics will allow the optimization of the performance in different topics like in clinical procedures and rehabilitation, medical devices and sports, among others. Strain gages were first applied to bone in a live animal in 40's and in 80's for the first time were applied fibre optic sensors to perform in vivo measurements of Achilles tendon forces in man. Fibre optic sensors proven to have advantages compare to conventional sensors and a great potential for biomechanical and biomedical applications. Compared to them, they are smaller, easier to implement minimally invasive, with lower risk of infection, highly accurate, well correlated, inexpensive and multiplexable. The aim of this review article is to give an overview about the evolution of the experimental techniques applied in biomechanics, from conventional to fibre optic sensors. In the next sections the most relevant contributions of these sensors, for strain and force in biomechanical applications, will be presented. Emphasis was given to report of in vivo experiments and clinical applications.