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Malaria diagnosis relies on optical microscopy and/or rapid diagnostic tests based on detecting specific malaria antigens. The clinical sensitivity of these methods is highly dependent on parasite density, with low levels of detection at low parasite density, challenging the worldwide malaria elimination efforts. Therefore, there is a need for diagnostic methods with higher sensitivity, demanding innovative diagnostics devices able to detect malaria at low parasite density and at early stages of the disease. We propose an innovative optical device for malaria diagnosis, based on optical reflectance spectrophotometry, for the detection of parasites through the quantification of haemozoin. For this purpose, a set of eight thin-film optical filters, based on multilayer stacks of MgO/TiO2 and SiO2/TiO2 thin-films, with high transmittance and low full width at half maximum (FWHM) at specific wavelengths, was designed and fully characterized (both numerically and experimentally). A preliminary assessment of its potential to reconstruct the original spectra of red blood cells was performed, both in uninfected and Plasmodium falciparum-infected samples. The obtained results show that, although the experimental filters have a non-ideal performance characteristic, they allow us to distinguish, based on only 8 discrete points in the optical spectrum, between healthy and malaria infected samples, up to a detection limit of 12 parasites/μL of red blood cells. Those results enhance the potential of using such a device for malaria diagnostics, aiming for non-invasiveness., Project NORTE-01-0145-FEDER-028178 funded by NORTE 2020 Portugal Regional Operational Program under PORTUGAL 2020 Partnership Agreement through the European Regional Development Fund and the Fundação para a Ciência e Tecnologia (FCT), IP. This work was also supported by national funds, through the Portuguese FCT, under the reference projects UIDB/04436/2020, UIDP/04436/2020, UIDB/50026/2020 and UIDP/50026/2020, and by the ICVS Scientific Microscopy Platform, member of the national infrastructure PPBIPortuguese Platform of Bioimaging (PPBI-POCI-01-0145-FEDER-022122). V. Baptista thanks FCT for the SFRH/BD/145427/2019 grant. Maria Isabel Veiga thanks FCT for her contract funding provided through 2020.03113.CEECIND. Susana Catarino thanks FCT for her contract funding provided through 2020.00215.CEECIND

In a context of increased environmental awareness, the Internet of Things has allowed individuals or entities to build their own connected devices to share data about the environment. These data are often obtained from widely available low-cost sensors. Some companies are also selling low-cost sensing kits for in-house or outdoor use. The work described in this paper evaluated, in the short term, the performance of a set of low-cost sensors for temperature, relative humidity, atmospheric pressure and carbon dioxide, commonly used in these platforms. The research challenge addressed with this work was assessing how trustable the raw data obtained from these sensors are. The experiments made use of 18 climatic sensors from six different models, and they were evaluated in a controlled climatic chamber that reproduced controlled situations for temperature and humidity. Four CO2 sensors from two different models were analysed through exposure to different gas concentrations in an indoor environment. Our results revealed temperature sensors with a very high positive coefficient of determination (r2 &ge, 0.99), as well as the presence of bias and almost zero random error, the humidity sensors demonstrated a very high positive correlation (r2 &ge, 0.98), significant bias and small-yet-relevant random error, the atmospheric pressure sensors presented good reproducibility, but further studies are required to evaluate their accuracy and precision. For carbon dioxide, the non-dispersive infra-red sensors demonstrated very satisfactory results (r2 &ge, 0.97, with a minimum root mean squared error (RMSE) value of 26 ppm), the metal oxide sensors, despite their moderate results (minimum RMSE equal to 40 ppm and r2 of 0.8&ndash, 0.96), presented hysteresis, environmental dependence and even positioning interference. The results suggest that most of the evaluated low-cost sensors can provide a good sense of reality at a very good cost&ndash, benefit ratio in certain situations.

This paper proposes a novel multifunctional isolated microinverter which is able to extract the maximum available power from a solar photovoltaic module and inject it into the power grid, while simultaneously charging a battery energy storage system (BESS). The proposed microinverter integrates a novel DC–DC power converter and a conventional DC–AC power converter. The DC–DC power converter is able to send electrical energy to the secondary side of a high-frequency transformer and to the BESS, using only two power switches. Throughout this paper, the converter topology, the operation modes, the control algorithms, and the development of a laboratory prototype of the proposed microinverter are described in detail. Moreover, simulation and experimental results are presented to demonstrate the feasibility of the proposed solution., This work has been supported by FCT—Fundação para a Ciência e Tecnologia within the R&DUnits Project Scope: UIDB/00319/2020. This work has been supported by the FCT Project QUALITY4POWERPTDC/EEI-EEE/28813/2017. Luis A. M. Barros is supported by the doctoral scholarship PD/BD/143006/2018 granted by the Portuguese FCT foundation. Mohamed Tanta was supported by FCT PhD grant with a reference PD/BD/127815/2016 granted by the Portuguese FCT agency. Tiago J. C. Sousa is supported by the doctoralscholarship SFRH/BD/134353/2017 granted by the Portuguese FCT agency.

Electric locomotives in AC traction power systems represent a huge single-phase non-linear load and, detrimentally, affect the power quality and the efficiency of the three-phase power grid. Nevertheless, along the last decades, power electronics are being used to mitigate power quality problems in the three-phase power grid. In particular, Rail Power Conditioner (RPC) helps to increase the loading capacity of traction substations and improve the power quality of three-phase power grids. As the main characteristics, an RPC can supply reactive power, suppress current harmonics and overcome currents imbalance of the three-phase power grid. On the other hand, the traction substations may be constituted by different types of power transformers. For instance, single-phase power transformers and open-delta (V/V) power transformers are widely used, while Scott power transformers are less frequently used, since they are more complex and expensive. In this framework, this work presents a review study of RPC topologies, including their operation modes, and a comprehensive comparison between the characteristics of the RPC topologies when using different types of AC traction substations and power transformers. This helps to ensure the correct selection of the RPC topology for a specific application, according to the main structure of the traction substation. Consequently, and based on the established review, it is possible to sort and allocate each RPC topology for limited or wider applications., This work was supported by the Portuguese Foundation of Science and Technology (FCT) (in Portuguese, Fundação para a Ciência e Tecnologia, within the R&D Units Project Scope: UIDB/00319/2020). The first author Mohamed Tanta is supported by FCT Ph.D. grant with a reference PD/BD/127815/2016.

This paper presents a cost- and time-effective wearable inertial sensor system, the InertialLAB. It includes gyroscopes and accelerometers for the real-time monitoring of 3D-angular velocity and 3D-acceleration of up to six lower limbs and trunk segment and sagittal joint angle up to six joints. InertialLAB followed an open architecture with a low computational load to be executed by wearable processing units up to 200 Hz for fostering kinematic gait data to third-party systems, advancing similar commercial systems. For joint angle estimation, we developed a trigonometric method based on the segments&rsquo, orientation previously computed by fusion-based methods. The validation covered healthy gait patterns in varying speed and terrain (flat, ramp, and stairs) and including turns, extending the experiments approached in the literature. The benchmarking analysis to MVN BIOMECH reported that InertialLAB provides more reliable measures in stairs than in flat terrain and ramp. The joint angle time-series of InertialLAB showed good waveform similarity (&gt, 0.898) with MVN BIOMECH, resulting in high reliability and excellent validity. User-independent neural network regression models successfully minimized the drift errors observed in InertialLAB&rsquo, s joint angles (NRMSE &lt, 0.092). Further, users ranked InertialLAB as good in terms of usability. InertialLAB shows promise for daily kinematic gait analysis and real-time kinematic feedback for wearable third-party systems.

This paper presents the analysis and experimental validation of a single-phase off-board multi-functional electric vehicle (EV) charging station (MF-EVCS), which has a single ac interface and two dc interfaces. As innovative aspects, the proposed MF-EVCS handles the interface of the ac power grid, the dc interface of a renewable energy source (RES), as well as the dc interface of an EV to perform dc charging or discharging of the batteries (in off-board grid-to-vehicle (G2V) or vehicle-to-grid (V2G) modes). Considering the power grid, the individual operation modes of the RES and the EV interfaces can be considered. Moreover, a combination of these modes is also possible. Besides, the MF-EVCS has as key innovative aspect the possibility of operating as an active power filter (APF), supporting the operation with reactive power and/or selected current harmonics. This possibility can be associated with any of the previous mentioned modes. These new features are framed in two distinct scenarios: in a smart home, where the ac-side current can be determined as a function of the other electrical appliances; in a smart grid, where the ac-side current can be determined as a requisite of the power grid. The proposed power theory, as well as the current control strategies for both ac-side and dc-side of the MF-EVCS, are presented in the paper for all the possible operation scenarios. A laboratory prototype was developed to validate the proposed MF-EVCS and the experimental results confirm its suitability for smart homes., INCT-EN -Instituto Nacional de Ciência e Tecnologia para Excitotoxicidade e Neuroproteção(DAIPESEV PTDC/EEI-EEE/30382/2017)

Concerns about greenhouse gas emissions are a key topic addressed by modern societies worldwide. As a contribution to mitigate such effects caused by the transportation sector, the full adoption of electric mobility is increasingly being seen as the main alternative to conventional internal combustion engine (ICE) vehicles, which is supported by positive industry indicators, despite some identified hurdles. For such objective, power electronics technologies play an essential role and can be contextualized in different purposes to support the full adoption of electric mobility, including on-board and off-board battery charging systems, inductive wireless charging systems, unified traction and charging systems, new topologies with innovative operation modes for supporting the electrical power grid, and innovative solutions for electrified railways. Embracing all of these aspects, this paper presents a review on power electronics technologies for electric mobility where some of the main technologies and power electronics topologies are presented and explained. In order to address a broad scope of technologies, this paper covers road vehicles, lightweight vehicles and railway vehicles, among other electric vehicles., This work has been supported by FCT – Fundação para a Ciência e Tecnologia with-in the Project Scope: UID/CEC/00319/2020. This work has been supported by the FCT Project DAIPESEV PTDC/EEI-EEE/30382/2017, and by the FCT Project new ERA4GRIDs PTDC/EEI-EEE/30283/2017. Tiago Sousa is supported by the doctoral scholarship SFRH/BD/134353/2017 granted by FCT.

Wi-Fi fingerprinting is widely used for indoor positioning and indoor navigation due to the ubiquity of wireless networks, high proliferation of Wi-Fi-enabled mobile devices, and its reasonable positioning accuracy. The assumption is that the position can be estimated based on the received signal strength intensity from multiple wireless access points at a given point. The positioning accuracy, within a few meters, enables the use of Wi-Fi fingerprinting in many different applications. However, it has been detected that the positioning error might be very large in a few cases, which might prevent its use in applications with high accuracy positioning requirements. Hybrid methods are the new trend in indoor positioning since they benefit from multiple diverse technologies (Wi-Fi, Bluetooth, and Inertial Sensors, among many others) and, therefore, they can provide a more robust positioning accuracy. In order to have an optimal combination of technologies, it is crucial to identify when large errors occur and prevent the use of extremely bad positioning estimations in hybrid algorithms. This paper investigates why large positioning errors occur in Wi-Fi fingerprinting and how to detect them by using the received signal strength intensities., This work has been supported by COMPETE: POCI-01-0145-FEDER-007043 and FCT-Fundação para a Ciência e Tecnologia within the scope of project UID/CEC/00319/2013, by the Portugal Incentive System for Research and Technological Development in the scope of the projects in co-promotion no 002814/2015 (iFACTORY 2015-2018), info:eu-repo/semantics/publishedVersion

In this paper, Isopropanol (IPA) availability during the anisotropic etching of silicon in Potassium Hydroxide (KOH) solutions was investigated. Squares of 8 to 40 m were patterned to (100) oriented silicon wafers through DWL (Direct Writing Laser) photolithography. The wet etching process was performed inside an open HDPE (High Density Polyethylene) flask with ultrasonic agitation. IPA volume and evaporation was studied in a dynamic etching process, and subsequent influence on the silicon etching was inspected. For the tested conditions, evaporation rates for water vapor and IPA were determined as approximately 0.0417 mL/min and 0.175 mL/min, respectively. Results demonstrate that IPA availability, and not concentration, plays an important role in the definition of the final structure. Transversal SEM (Scanning Electron Microscopy) analysis demonstrates a correlation between microloading effects (as a consequence of structure spacing) and the angle formed towards the (100) plane., This work was supported by FCT (Fundação para a Ciência e Tecnologia) in the scope of the project PTDC/EBB-EBI/120334/2010 and by FEDER funds through the “Eixo I do Programa Operacional Fatores de Competitividade” (POFC) QREN, project reference COMPETE: FCOMP-01-0124-FEDER-020241. First author thanks FCT for scholarship grant SFRH/BD/74975/2010. INESC-MN and acknowledges Pest-OE/CTM/LA0024/2011 project.

In this work is proposed the design of a system to create and handle an Electric Vehicle (EV) community, based on social networks collaborative approach and a credit mechanism to incentive participation and mechanism to incentive participation and divide profits. This system is part of a V2G (Vehicle-to-Grid) module that allows EV owners to be aggregated in communities and participate in the electricity market. With this system it is possible for the EV owners to win money while the EVs are parked and plugged, delivering back to the electrical grid part of the energy stored in the batteries, increasing the attractiveness of EVs., This work is financed by FEDER Funds, through the Operational Programme for Competitiveness Factors – COMPETE, and by National Funds through FCT – Foundation for Science and Technology of Portugal, under the project PTDC/EEA-EEL/104569/2008 and the project MIT-PT/EDAM-SMS/0030/2008.