Tuning of fiber optic surface reflectivity through graphene oxide-based Layer-by-Layer film coatings

SFRH/BD/135820/2018 UID/EEA/50014/2019 UID/FIS/00068/2019 M-ERA-NET2/0002/2016The use of graphene oxide-based coatings on optical fibers are investigated, aiming to tune the reflectivity of optical fiber surfaces for use in precision sensing devices. Graphene oxide (GO) layers are successfully deposited onto optical fiber ends, either in cleaved or hollow microspheres, by mounting combined bilayers of polyethylenimine (PEI) and GO layers using the Layer-by-Layer (LbL) technique. The reflectivity of optical fibers coated with graphene oxide layers is investigated for the telecom region allowing to both monitor layer growth kinetics and cavity characterization. Tunable reflective surfaces are successfully attained in both cleaved optical fibers and hollow microsphere fiber-based sensors by simply coating them with PEI/GO layers through the LbL film technique.publishersversionpublishe

Acoustic optical fiber sensor based on graphene oxide membrane

A Fabry–Pérot acoustic sensor based on a graphene oxide membrane was developed with the aim to achieve a faster and simpler fabrication procedure when compared to similar graphene-based acoustic sensors. In addition, the proposed sensor was fabricated using methods that reduce chemical hazards and environmental impacts. The developed sensor, with an optical cavity of around 246 µm, showed a constant reflected signal amplitude of 6.8 ± 0.1 dB for 100 nm wavelength range. The sensor attained a wideband operation range between 20 and 100 kHz, with a maximum signal-to-noise ratio (SNR) of 32.7 dB at 25 kHz. The stability and sensitivity to temperatures up to 90◦C was also studied. Moreover, the proposed sensor offers the possibility to be applied as a wideband microphone or to be applied in more complex systems for structural analysis or imaging.publishersversionpublishe

Fiber Fabry-Perot interferometer for curvature sensing

A curvature sensor based on an Fabry-Perot (FP) interferometer was proposed. A capillary silica tube was fusion spliced between two single mode fibers, producing an FP cavity. Two FP sensors with different cavity lengths were developed and subjected to curvature and temperature. The FP sensor with longer cavity showed three distinct operating regions for the curvature measurement. Namely, a linear response was shown for an intermediate curvature radius range, presenting a maximum sensitivity of 68.52 pm/m-1. When subjected to temperature, the sensing head produced a similar response for different curvature radii, with a sensitivity varying from 0.84 pm/°C to 0.89 pm/°C, which resulted in a small cross-sensitivity to temperature when the FP sensor was subjected to curvature. The FP cavity with shorter length presented low sensitivity to curvature

Outdoor tourism in the North of Portugal from the perspective of tourist entertainment companies (TEC)

Based on the perception of those responsible for Tourist Entertainment Companies (TEC), the objective of the research is to contribute to the characterization of Outdoor Tourism (OT). Exploratory qualitative research was carried out through 38 in-depth individual interviews. The territory geography, the experiences, and the internal market were considered relevant aspects. In addition, seasonality and climate were identified as significant factors in defining the offer, which can favour the preservation of the environment. Moreover, the risk of the activities was considered low. The interviewees suggested integrating everyone involved in a network to explore the region's potential, as well as to support activities and promote the region. The radical experience, adventure, and getting out of the routine were identified as motivations for the search, as well as contact with nature and the landscape. The research is limited to the North Region of Portugal, and it brings together the most different needs, desires, and expectations for tourism demand. Strengthening OT can favour employability and, consequently, economic and social balance while promotion of the activity can be explored through the customers' previous experience. The evaluations, testimonials, and word of mouth (WOM) being added value that can be optimized through social networks and digital marketing.This project is being carried out within the scope of the TURNOUT Project-Development of Outdoor Tourism of Northern Portugal, POCI-01-0145-ERDF-032289, financed by the European Investment Fund Regional Development (ERDF) through the Operational Program of Competitiveness and Innovation (POCI) and the Foundation for Science and Technology, IP (OE). UNIAG, R&D unit funded by the FCT-Portuguese Foundation for the Development of Science and Technology, Ministry of Science, Technology and Higher Education. “Project Code Reference: UIDB/04752/2020”. This project also thanks to the reviewers of the ICTR21 conference for their improvement inputs to the paper.info:eu-repo/semantics/publishedVersio

Supply-side perspectives on outdoor tourism in the North of Portugal

Nowadays, the tourism sector presents many opportunities and challenges. Outdoor Tourism (OT), due to the unusual situation experienced by the pandemic caused by COVID-19, maybe one of the main opportunities to promote the local development of tourist destinations. Most of the literature developed in this context has focused the demand side. Therefore, the investigation intended to fill this gap, considering the perspective of the supply side, taking into account a vision of sustainable development. To meet this gap, the main objective is to contribute to the characterization of Outdoor Tourism (OT) in the North of Portugal, and understand the potential of OT in the perspective of supply., thirty-eight tourist entertainment companies (TEC) were interviewed to assess supply and perceived customers’ motivations. Of the seven Nomenclature of Territorial Units for Statistical Purposes (NUTS), the Northern region was considered to be an area with enormous potential for Nature-related tourist). For the supply side, seasonality and climate were identified as important factors supporting environment preservation. Radical experiences, adventure and getting out of the routine were identified as motivating demand factors, as well as the contact with Nature and the landscape. We have also observed that if we consider the stimulation of the local economy by OT, there is still a lot to do. The evidence pointed to some social imbalance, namely related to employability. Employees were hired according to the evolution of demand, which favours unemployment and social instability. Also, the tourists/costumers are the main channels of communication of the activities; the word-ofmouth (WOM) of costumers’ experiences, personally or through online social media, takes on a prominent role. In this sense, tourists’ online reviews, testimonies, and word-of-mouth can be optimized through social networks and digital marketing. Finally, to evaluate the region's potential for the OT, the interviewees suggested integrating the players involved with the OT into a single network, supporting the activities and promoting the region.The authors would like to thanks the Project “TURNOUT: Desenvolvimento do Turismo Outdoor da Região Norte de Portugal”, with the reference POCI-01-0145-FEDER-032289, and funded by the European Regional Development Fund (FEDER) (through the Operational Programme ‘Innovation and competitiveness’) and by the Portuguese Foundation for the Development of Science (FCT), of the Ministry of Science, Technology and Higher Education. This work is, also, funded by National Funds through the Foundation for Science and Technology under the project UIDB/04752/2020info:eu-repo/semantics/publishedVersio