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Iniciação à investigação em educação matemática: exemplo de duas tarefas com re...
Andreia Castro; Filipa Santana; Teresa Neto; Isabel ÓrfãoEste texto apresenta algumas tarefas desenhadas no âmbito da unidade curricular, Seminário de Investigação em Didática, que se desenvolve em estreita ligação com a prática de ensino supervisionada, do mestrado em Ensino da Matemática no 3ºCEB e Secundário. As tarefas apresentadas têm como finalidade a reflexão sobre alguns pr...
Continuous-flow precipitation of hydroxyapatite in ultrasonic microsystems
Castro, Filipa; Kuhn, Simon; Jensen, Klavs; Ferreira, António; Rocha, Fernando; Vicente, A. A.; Teixeira, J. A.This paper describes the continuous-flow precipitation of hydroxyapatite Ca5(PO4)3OH (HAp) in two ultrasonic microreactors using diluted aqueous solutions of calcium and phosphate at 37 °C. Precipitation of HAp was first carried out in a tubular microreactor immersed in an ultrasonic bath, where single-phase (laminar) flow and segmented gas-liquid flow were both evaluated. The single-phase flow study was then c...
Process Intensification for the production of hydroxyapatite nanoparticles
Castro, FilipaTese de doutoramento em Bioengenharia ; Precipitation processes are widely used in chemical industry for the production of particulate solids. In these processes, the chemical and physical nature of synthesized particles is of key importance. The traditional stirred tank batch reactors are affected by non-uniform mixing of reactants, often resulting in broad particle size distribution. The main objective of th...
Diverse physical growth trajectories in institutionalized portuguese children b...
Martins, Carla; Belsky, Jay; Marques, Sofia; Baptista, Joana; Silva, Joana; Mesquita, Ana Raquel Marcelino; Castro, Filipa; Sousa, Nuno; Soares, IsabelThe authors would like to thank the students involved in the data collection and coding, and especially the children, caregivers, and other institutional staff who participated in the study. Funding from Fundação para a Ciência e Tecnologia. ; Objective: To identify and analyze diverse longitudinal trajectories of physical growth of institutionalized children and their relation to child, family, and institutio...
Process intensification and optimization for hydroxyapatite nanoparticles produ...
Castro, Filipa; Kuhn, Simon; Jensen, Klavs; Ferreira, António; Rocha, F.; Vicente, A. A.; Teixeira, J. A.Precipitation processes are widely used in industry for the production of particulate solids. Efficient mixing of the reagents is of major importance for the chemical and physical nature of the synthesized particles. Recently, microreactors have been studied to overcome homogeneity problems found when using stirred tank batch reactors. The present work investigated an ultrasonic tubular microreactor for the con...
Continuous-flow precipitation of hydroxyapatite at 37 °C in a meso oscillatory ...
Castro, Filipa; Ferreira, António; Rocha, Fernando; Vicente, A. A.; Teixeira, J. A.Continuous-flow precipitation of hydroxyapatite (HAp) was investigated in a meso oscillatory flow reactor (meso- OFR) and in a scaled-up meso-OFR, obtained by associating in series eight vertical meso-ORFs. Experiments were carried out under near-physiological conditions of temperature and pH, using fixed frequency ( f = 0.83 Hz) and amplitude (x0 = 4.5 mm), and varying the residence time from 0.4 to 6.7 min. I...
Precipitation of hydroxyapatite at 37 °C in a meso oscillatory flow reactor ope...
Castro, Filipa; Ferreira, António; Rocha, F. A.; Vicente, A. A.; Teixeira, J. A.A meso oscillatory flow reactor (OFR) was successfully applied for the precipitation of hydroxyapatite (HAp) nanoparticles. Mixing efficiency of the mesoreactor operated batchwise in a vertical tube was evaluated at constant power density, by monitoring variation of hue values upon mixing both spatially and temporally. The best operating conditions for fast mixing and a more homogeneous reaction medium were ver...
Characterization of intermediate stages in the precipitation of hydroxyapatite ...
Castro, Filipa; Ferreira, António; Rocha, F. A.; Vicente, A. A.; Teixeira, J. A.Precipitation of hydroxyapatite Ca 5(PO 4) 3OH (HAp) was carried out by mixing a saturated calcium hydroxide aqueous solution with an orthophosphoric acid aqueous solution at 37°C. In order to promote optimal conditions for the production of HAp with high yields, mixing of the reaction medium was assured by a novel metal stirrer. Different experimental conditions were studied varying the mixing Ca/P molar ratio...
Avaliação da qualidade de ar na cidade de Santarém
Castro, Filipa Mara FreitasAs áreas urbanas caracterizam-se pela sua elevada densidade populacional aliada ao desenvolvimento económico, factores que exercem uma crescente pressão sobre a sua qualidade do ar. Neste sentido, a aposta no controlo e monitorização da qualidade do ar é fundamental, a qual passa pela aplicação de modelos que simulam as diferentes fontes emissoras e o seu contributo para as concentrações dos poluentes na atmosf...
First characterization of the ecotoxicologic effects of waters from North of Po...
Castro, Filipa; Machado, Alexandra; Nunes, BrunoWater contamination can result in the deterioration of its ecological quality and value for human consumption. The present work assessed the ecotoxicologic effects of potential contaminants present in several water samples from varied provenience (aquifer, municipal spring, rivers, public distribution system and treated effluents from a car garage). The adopted end-point was immobilization of Daphnia magna juve...
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