656 research outputs found
Estado nutricional pré-concecional e aumento ponderal na gravidez: estudo de acompanhamento na ilha do Faial
Perfil de suplementação antes e durante a gestação: estudo de acompanhamento na ilha do Faial
Aporte e adequação nutricional antes e durante a gestação: estudo de acompanhamento na ilha do Faial
Application of the front tracking method in micro flow measuring devices
18HLT08This work has the main objective to develop a calibration method for micro flow measuring devices based on the front tracking principle, in the Volume and Flow Laboratory (LVC) of the Portuguese Institute of Quality (IPQ), in a partnership with and the Department of Mechanical and Industrial Engineering (DEMI) of The New University of Lisbon under the project MeDD II – Metrology for Drug Delivery. The experimental setup consists of using a camera and Python software to track the distance traveled by the meniscus of a liquid inside a capillary tube and calculate the flow rate according to appropriated equations. Experimental tests using a flow generator and a flow meter were carried out for different flow rates. Two different setups with cameras of different specifications were tested. To validate the developed front tracking method, internal comparisons using a Nexus pump and a Sensirion meter were performed with the gravimetric and interferometric methods already implemented at LVC. The results obtained by these two comparisons were consistent. This new developed method can therefore be used to calibrate flow devices from 1000 μL/h down to 1 μL/h with an uncertainty value from 2% to 7% (k = 2). The calibration procedure is easy to apply and can be used for both syringe and flow meters. This method is simple to implement in a laboratory and the setup is relatively cheap compared to the gravimetric or interferometric method. Finally, the front tracking method was applied to the calibration of an implantable insulin pump used by diabetic patients.publishersversionpublishe
Development of an experimental setup for micro flow measurement using the front tracking method
Funding Information: This work performed under 18HLT08 MeDDII project has received funding from the EMPIR programme co-financed by the Participating States and from the European Union's Horizon 2020 research and innovation programme .This work has the main objective to develop a method for microflow measurement using the front tracking principle under the project MeDD II – Metrology for Drug Delivery. The experimental setup uses a high-resolution camera and an image processing software to track the distance travelled by the meniscus of a liquid in a capillary tube and calculate the flow rate. Experimental tests using a flow generator were carried out for different flow rates using two different cameras. To validate the developed front tracking method, an internal comparison was made with the gravimetric method in LVC. The results obtained by this comparison were consistent. This developed method can be used to calibrate flow devices down to 1 μL/h with an uncertainty value of 7% (k = 2).publishersversionpublishe
Workshop em Ciências da Terra e do Espaço - Livro de Actas 2019
Nas últimas décadas, um enorme e crescente interesse público e científico acerca do
Sistema Terra desencadeou por toda a parte um enorme esforço no sentido da sua
compreensão. Este interesse deriva, não apenas da importância do conhecimento
científico, mas também da ideia, cada vez mais consensual, de que o desenvolvimento
humano não pode gerar desequilíbrios irreversíveis neste sistema e que o investimento no
conhecimento científico no domínio das Ciências da Terra desempenha um papel
fundamental.
As Ciências da Terra dizem respeito ao conhecimento do nosso planeta e do espaço
vizinho adjacente. O objeto de estudo é, por conseguinte, um sistema de enorme
complexidade no seio do qual ocorrem, a diferentes escalas temporais e espaciais, intensas
interações entre os subsistemas que o compõem. Assim, compreender a “história” deste
sistema e os processos que nele ocorreram, bem como a caracterização atual e a previsão
da sua evolução futura, constitui um enorme desafio, para o qual concorre o conhecimento
pluridisciplinar e transversal em diversos domínios das Ciências Físicas e Naturais, mas
também da capacidade de observação detalhada dos parâmetros relevantes para a
caracterização do sistema. Aprofundar o conhecimento do nosso planeta e partir para a
compreensão da sua dinâmica e sua evolução futura obriga, também, a um enorme esforço
no desenvolvimento tecnológico em domínios como os da deteção remota e in situ e no
desenvolvimento da modelação computacional.
É neste contexto que surge a quinta edição do Workshop em Ciências da Terra da
Atmosfera e do Espaço da Universidade de Évora (WCTAE). Neste livro encontram-se
reunidos os artigos de investigação dos estudantes que frequentaram a unidade curricular
“Seminário do Programa de Doutoramento em Ciências da Terra e do Espaço (DCTE) e
do Mestrado em Ciências e Tecnologia da Terra da Atmosfera e do Espaço (MCTTAE).
O livro reflete a investigação dos estudantes já em contexto de tese e o seu esforço para
bem comunicar em ambiente científico. Os 9 trabalhos submetidos abrangem diversas
temáticas, desde a Geologia, passando pela Física da Atmosfera até à Energia e Ambiente.
Esta diversidade temática a que tivemos a oportunidade de assistir no dia 30 de janeiro de
2019, data da realização da 5a edição do WCTAE, reflete a transversalidade científica
inerente à forma atual de encarar a construção do conhecimento acerca do Sistema Terra
Uncertainty calculations in optical methods used for micro flow measurement
Funding Information: This work performed under MeDDII project has received funding from the EMPIR programme co-financed by the Participating States and from the European Union's Horizon 2020 research and innovation programme .This work aims to describe the uncertainty calculation methodologies associated with two optical methods used for micro flow measurements, both developed at the Portuguese Institute for Quality (IPQ) under the EMPIR project MeDD II – Metrology for Drug Delivery framework. One of the methods is the front track which consists of tracking the meniscus of a liquid inside a capillary tube over time. The second method is the pending drop method that relies on measuring the volume growth of a drop over time. Both methods use a camera to capture images and convert them in volume or displacement length to determine flow rate. The uncertainty calculations will be presented in detail. The values obtained for the front track method are much smaller than for the pending drop method, specially at very low flow rates.publishersversionpublishe
A comprehensive comparison of voltage and current control techniques for three-phase VSI converters
Converting electrical energy from direct current to alternate current, or vice versa, is one of the most frequently performed tasks in today’s electrical systems. The Voltage Source Inverter (VSI) is the most widely used topology to accomplish this task. This paper compares the performance of three control algorithms for voltage source inverter (VSI) with PI, PR and MP control algorithms were applied for voltage control and current control. For voltage control the VSI synthesizes the sinusoidal voltage system for an islanded application. In current control the VSI injects energy into the power grid by synthesizing sinusoidal currents. A general comparison is made of the performance of the three control algorithms under the presented conditions, helping to choose the control algorithm to use in a given application.This work has been supported by FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UIDB/00319/2020. This work has been supported by the FCT Project QUALITY4POWER PTDC/EEI-EEE/28813/2017, and by the FCT Project DAIPESEV PTDC/EEI-EEE/30382/2017. Mr. Luis A. M. Barros is supported by the doctoral scholarship PD/BD/143006/2018 granted by the Portuguese FCT foundation
Tandem Thio-Michael Addition/Remote Lactone Activation of 5-Hydroxymethylfurfural-Derived δ-Lactone-Fused Cyclopentenones
Funding Information: We thank the Fundação para a Ciência e a Tecnologia (SFRH/BD/120829/2016, SFRH/BD/148211/2019, UIDB/04138/2020, UIDP/04138/2020, PTDC/QUI‐QOR/32008/2017 and GHTM‐UID/04413/2020). The project leading to this application has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 951996. J. A. S. C. thanks the Fundação para a Ciência e a Tecnologia (FCT) for Scientific Employment Stimulus 2020/02383/CEECIND. Publisher Copyright: © 2022 The Authors. ChemSusChem published by Wiley-VCH GmbH.The creation of structurally diverse chemical entities from fairly simple biorefinery products remains a challenge. In this work 5-hydroxymethylfurfural (HMF) was identified as a key synthon for preparing highly complex cyclopentenones (CP) via tandem 1,4-addition/elimination/remote lactone activation to external O- and N-nucleophiles in δ-lactone-fused-CPs hotspots. This scaffold was also reactive enough to be incorporated into model cysteine-peptides in low concentrations, paving the way to a potential translation generating complexity in the synthesis of small peptides. The new enones also exhibited activity against intraerythrocytic Plasmodium falciparum (IC50=1.32 μm).publishersversionpublishe
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