93 research outputs found

    Sound wave phase processing for precise positioning

    Get PDF
    Tese de mestrado. Métodos computacionais em Ciências e Engenharia. Faculdade de Engenharia. Universidade do Porto. 200

    The Sea (Lisbon, 28th November - 1st December 2022)

    Get PDF
    UIDB/00749/2020 UIDP/00749/2020 DL 57/2016/CP1453/CT0015publishersversionpublishe

    Preliminary evaluation of a microfluidic device for blood separation and deformation assessment

    Get PDF
    This work was supported by FCT with the reference project UID/EEA/04436/2013, by FEDER funds through the COMPETE 2020 – Programa Operacional Competitividade e Internacionalização (POCI) with the reference project POCI-01- 0145-FEDER- 006941. V. Faustino and S.O. Catarino thank, respectively, the FCT for the grants SFRH/BD/99696/2014 and SFRH/BPD/108889/2015, supported by national funds from Ministérios da Ciência, Tecnologia e Ensino Superior and by FSE through the POCH - Programa Operacional Capital Humano

    A Passive Microfluidic Device Based on Crossflow Filtration for Cell Separation Measurements: A Spectrophotometric Characterization

    Get PDF
    Microfluidic devices have been widely used as a valuable research tool for diagnostic applications. Particularly, they have been related to the successful detection of different diseases and conditions by assessing the mechanical properties of red blood cells (RBCs). Detecting deformability changes in the cells and being able to separate those cells may be a key factor in assuring the success of detection of some blood diseases with diagnostic devices. To detect and separate the chemically modified RBCs (mimicking disease-infected RBCs) from healthy RBCs, the present work proposes a microfluidic device comprising a sequence of pillars with different gaps and nine different outlets used to evaluate the efficiency of the device by measuring the optical absorption of the collected samples. This latter measurement technique was tested to distinguish between healthy RBCs and RBCs chemically modified with glutaraldehyde. The present study indicates that it was possible to detect a slight differences between the samples using an optical absorption spectrophotometric setup. Hence, the proposed microfluidic device has the potential to perform in one single step a partial passive separation of RBCs based on their deformability.Research supported by FCT with the reference projects POCI-01-0145-FEDER-016861 (PTDC/QEQ-FTT/4287/2014), NORTE-01-0145-FEDER-029394 (PTDC/EMD-EMD/29394/2017), NORTE-01-0145-FEDER-030171 (PTDC/EME-SIS/30171/2017), UID/EEA/04436/2013, by FEDER funds through the COMPETE 2020, NORTE2020, PORTUGAL2020-Programa Operacional Competitividade e Internacionalizacao (POCI) with the reference project POCI-01-0145-FEDER-006941 and by the NORTE-01-0145-FEDER-028178 (PTDC/EEI-EEE/28178/2017) project, funded 85% from Programa Operacional Regional do Norte and 15% from FCT.info:eu-repo/semantics/publishedVersio

    Label-free multi-step microfluidic device for mechanical characterization of blood cells: Diabetes type II

    Get PDF
    The increasing interest to establish significant correlations between blood cell mechanical measurements and blood diseases, has led to the promotion of microfluidic devices as attractive clinical tools for potential use in diagnosis. A multi-step microfluidic device able to separate red and white blood cells (RBCs and WBCs) from plasma and simultaneously measure blood cells deformability (5 and 20% of hematocrit) is presented in this paper. The device employs passive separation based on the cross-flow filtration principle, introduced at each daughter channel. At the outlets, hyperbolic geometries allow single-cell deformability analysis. The device was tested with blood from five healthy and fifteen diabetic type II voluntary donors. The results have shown that WBCs have lower deformability than RBCs, and no significant differences were observed in WBCs from healthy and pathological blood samples. In contrast, RBCs have shown significant differences, with pathological cells exhibiting lower deformability. Shear rheology has shown that blood from patients with type II diabetes has higher viscosity than blood from healthy donors. This microfluidic device has demonstrated the ability to reduce cell concentration at the outlets down to 1%, an ideal cell concentration for assessing the blood cells deformability, under healthy and pathological conditions. The results provide new insights and quantitative information about the hemodynamics of in vitro type II diabetes mellitus RBCs. Thus, such device can be a promising complement in clinical diagnosis and biological research as part of an integrated blood-on-a-chip system.This work was supported by Projects NORTE-01-0145-FEDER- 028178, NORTE-01-0145-FEDER-029394, NORTE-01-0145-FEDER- 030171 funded by COMPETE2020, NORTE2020, PORTUGAL2020, and FEDER. This work was also supported by Fundação para a Ciência e a Tecnologia (FCT) under the strategic grants UIDB/04077/2020 and UIDB/00532/2020. D. Pinho and V. Faustino acknowledge the Ph.D. scholarships SFRH/BD/89077/2012 and SFRH/BD/99696/2014, respectively, both provided by FCT. Susana Catarino thanks FCT for her contract funding provided through 2020.00215.CEECIND. F. T. Pinho is thankful to FCT for financial support through projects LA/P/0045/2020 of the Associate Laboratory in Chemical Engineering (ALiCE) and projects UIDB/00532/2020 and UIDP/00532/2020 of Centro de Estudos de Fenómenos de Transporte.info:eu-repo/semantics/publishedVersio

    Label-free multi-step microfluidic device for mechanical characterization of blood cells: diabetes type II

    Get PDF
    The increasing interest to establish significant correlations between blood cell mechanical measurements and blood diseases, has led to the promotion of microfluidic devices as attractive clinical tools for potential use in diagnosis. A multi-step microfluidic device able to separate red and white blood cells (RBCs and WBCs) from plasma and simultaneously measure blood cells deformability (5 and 20% of hematocrit) is presented in this paper. The device employs passive separation based on the cross-flow filtration principle, introduced at each daughter channel. At the outlets, hyperbolic geometries allow single-cell deformability analysis. The device was tested with blood from five healthy and fifteen diabetic type II voluntary donors. The results have shown that WBCs have lower deformability than RBCs, and no significant differences were observed in WBCs from healthy and pathological blood samples. In contrast, RBCs have shown significant differences, with pathological cells exhibiting lower deformability. Shear rheology has shown that blood from patients with type II diabetes has higher viscosity than blood from healthy donors. This microfluidic device has demonstrated the ability to reduce cell concentration at the outlets down to 1%, an ideal cell concentration for assessing the blood cells deformability, under healthy and pathological conditions. The results provide new insights and quantitative information about the hemodynamics of in vitro type II diabetes mellitus RBCs. Thus, such device can be a promising complement in clinical diagnosis and biological research as part of an integrated blood-on-a-chip system.This work was supported by Projects NORTE-01-0145-FEDER-028178, NORTE-01-0145-FEDER-029394, NORTE-01-0145-FEDER-030171 funded by COMPETE2020, NORTE2020, PORTUGAL2020, and FEDER. This work was also supported by Fundacao para a Ciencia e a Tecnologia (FCT) under the strategic grants UIDB/04077/2020 and UIDB/00532/2020. D. Pinho and V. Faustino acknowledge the Ph.D. scholarships SFRH/BD/89077/2012 and SFRH/BD/99696/2014, respectively, both provided by FCT. Susana Catarino thanks FCT for her contract funding provided through 2020.00215.CEECIND. F. T. Pinho is thankful to FCT for financial support through projects LA/P/0045/2020 of the Associate Laboratory in Chemical Engineering (ALiCE) and pro-jects UIDB/00532/2020 and UIDP/00532/2020 of Centro de Estudos de Fenomenos de Transporte

    Distribution models of deep-sea elasmobranchs in the Azores, Mid-Atlantic Ridge, to inform spatial planning

    Get PDF
    Elasmobranchs inhabiting depths beyond 200 m are extremely susceptible to overexploitation but are extracted by fisheries around the world either as target species or as bycatch. There is little information available to formulate management strategies to reduce elasmobranch-fishery interactions in the deep sea. In European Union waters, prohibiting the catches of deep-sea elasmobranchs has provided the necessary impetus to study by-catch avoidance of these threatened species. We used over 20 years of fisheries-independent and fisheries-dependent data to model the spatial distribution of 15 species of deep-sea elasmobranchs (12 sharks and 3 rays) captured frequently in the Exclusive Economic Zone of the Azores Archipelago (Mid-Atlantic Ridge) to explore spatial management to reduce unwanted catches of these species. We applied Generalised Additive Models to predict the probability of presence of 15 species, as well as the abundance of 6 of those species, within the Azores EEZ and neighbouring seamounts (up to 2000 m depth), using environmental and operational variables as predictors. Our results identified that depth is most influential in determining the distribution of these sharks and rays, in addition to seafloor topography. Distinctive bathymetric features such as seamounts and ridges were highlighted as areas where the probability of presence of the greatest number of species overlapped. Although not related to habitat, gear type influenced the capture probability of certain species, with the artisanal handline, gorazeira, having lower captures than bottom longline. Our results support using depth-based, area-based, and gear-based tactics to design management measures to reduce elasmobranch bycatch, for more sustainable deep-sea fisheries.Postprint2,42

    A review of novel heat transfer materials and fluids for aerospace applications

    Get PDF
    The issue of thermal control for space missions has been critical since the early space missions in the late 1950s. The demands in such environments are heightened, characterized by significant temperature variations and the need to manage substantial densities of heat. The current work offers a comprehensive survey of the innovative materials and thermal fluids employed in the aerospace technological area. In this scope, the materials should exhibit enhanced reliability for facing maintenance and raw materials scarcity. The improved thermophysical properties of the nanofluids increase the efficiency of the systems, allowing the mass/volume reduction in satellites, rovers, and spacecraft. Herein are summarized the main findings from a literature review of more than one hundred works on aerospace thermal management. In this sense, relevant issues in aerospace convection cooling were reported and discussed, using heat pipes and heat exchangers, and with heat transfer ability at high velocity, low pressure, and microgravity. Among the main findings, it could be highlighted the fact that these novel materials and fluids provide enhanced thermal conductivity, stability, and insulation, enhancing the heat transfer capability and preventing the malfunctioning, overheating, and degradation over time of the systems. The resulting indicators will contribute to strategic mapping knowledge and further competence. Also, this work will identify the main scientific and technological gaps and possible challenges for integrating the materials and fluids into existing systems and for maturation and large-scale feasibility for aerospace valorization and technology transfer enhancement.This work has been funded by FCT/MCTES (PIDDAC) through the base funding from the following research units: UIDP/50009/2020-FCT and UIDB/50009/2020-FCT, UIDB/00532/2020, LA/P/0045/2020, UIDB/04077/2020, and UIDP/04077/2020. The authors are also grateful for FCT funding through 2022. 03151.PTDC, PTDC/EME-TED/7801/2020, POCI-01-0145-FEDER-016861, POCI-01-0145-FEDER-028159, 2022. 02085.PTDC (https://doi.org/10.54499/2022.02085.PTDC, accessed on 25 March 2024), funded by COMPETE2020, NORTE2020, PORTUGAL2020, and FEDER. Glauco Nobrega was supported by the doctoral grant PRT/BD/153088/2021, financed by the Portuguese Foundation for Science and Technology (FCT), under the MIT Portugal Program. Pinho D. and Susana O. Catarino thank FCT for her contract funding provided through 2021.00027.CEECIND, 2020.00215.CEECIND (DOI: https://doi.org/10.54499/2020.00215.CEECIND/CP1600/CT0009, accessed on 25 March 2024), respectively. The authors are also grateful to the Fundação para a Ciência e a Tecnologia (FCT), Avenida D. Carlos I, 126, 1249–074 Lisboa, Portugal, for partially financing the Project “Estratégias interfaciais de arrefecimento para tecnologias de conversão com elevadas potências de dissipação”, ref. PTDC/EMETED/7801/2020, Associação do Instituto Superior Técnico para a Investigação e o Desenvolvimento (IST-ID). José Pereira also acknowledges FCT for his PhD fellowship (Ref. 2021. 05830.BD). The authors are also grateful for FCT funding through 2022.03151.PTD and LA/P/0083/2020 IN + -IST-ID. The authors are also grateful for FCT funding through 2022.03151.PTD and LA/P/0083/2020 IN + -IST-ID and through UIPD/50009/2020-FCT and UIDB/50009—FCT. Ana Moita also acknowledges FCT for partially financing her contract through CEECINST/00043/2021/CP2797/CT0005, doi:https://doi.org/10.54499/CEECINST/00043/2021/CP2797/CT0005, accessed on 25 March 2024. The authors also acknowledge Exército Português for their support through projects CINAMIL Desenvolvimento de Sistemas de Gestão Térmica e Climatização de equipamento NBQ and COOLUAV—Sistema de arrefecimento da componente eletrónica e baterias em veículos militares não tripulados

    First record of the opal chimaera, Chimaera opalescens (Holocephali: Chimaeridae) and revision of the occurrence of the rabbitfish Chimaera monstrosa in the Azores waters

    Get PDF
    The presence of the opal chimaera, Chimaera opalescens, is reported for the first time in the deep waters of the Azores, with the capture of four specimens by fishermen and the video recording of an additional five individuals. Species identification was supported by the 646 bp sequenced fragment of the mitochondrial gene cytochrome oxidase subunit I. Because C. opalescens is a recently recognised species that had been recurrently misidentified as rabbitfish, Chimaera monstrosa, the historical data of C. monstrosa in the Azores were reviewed to assess the possible presence of both Chimaera species in the region. Although several authors have reported the occurrence of C. monstrosa in the Azorean waters since the 1800s, the majority of these are based on only three specimens caught during the late 1800s. The investigation performed using literature and examination of the museum specimens still available concluded that the most likely scenario is that C. monstrosa is absent from the Azores and past records of that species in the region are most likely misidentifications of C. opalescens.publishedVersio
    corecore