Percorrer por autor "Reis, A."
A mostrar 1 - 3 de 3
Resultados por página
Opções de ordenação
- Características do tomate de estufa – cultivo em substrato vs cultivo em soloPublication . Saraiva, R.; Dias, Igor; Reis, A.; Matos, A.; Faro, M.; Oliveira, MargaridaEm Portugal, a região do Oeste é responsável pela produção de cerca de 100 000 toneladas de tomate por ano em estufa. A importância da cultura para a região é inegável e a aposta no setor é fundamental, com os sistemas sem solo a ganhar ênfase, numa cultura que é ainda predominantemente conduzida em solo. De modo a avaliar a possível vantagem da alteração do sistema produtivo para os produtores da região, foi conduzido um estudo comparativo da qualidade dos frutos associada a dois sistemas de produção: sem solo (A) e em solo (S) em estufas na região do Oeste. A maioria dos parâmetros analisados não apresentou diferenças significativas entre modos de produção, no entanto foram detetadas algumas diferenças importantes, nomeadamente nos sólidos solúveis totais e índice de maturação, que se revelaram mais elevados em A, enquanto os frutos da estufa S apresentaram coordenadas de cor que revelam maior luminosidade, tonalidades mais amareladas e cor mais forte e brilhante.
- Kinematical constrictions during Breaststroke swimming with a portable gas analyzer snorkelPublication . Reis, V.; Silva, A.; Barbosa, T.; Brito, J.; Reis, A.; Louro, Hugo; Conceição, A.OBJECTIVE: To determine the kinematical constrictions in maximal breaststroke swimming bouts with the AquaTrainer snorkel (Cosmed, Rome, Italy). METHODS: Seven national level breaststrokers performed two maximal bouts of 100-m swims (separated by 48 hours): (i) one bout connected to the AquaTrainer snorkel (constricted swim); (ii) one bout without the snorkel (free swim). The swims were videotaped in sagittal plane with a pair of cameras providing a dual projection from both above and underwater. The study comprised kinematical analysis of stroke cycles using APAS and a VCR (f = 50 Hz). To create a single dual projection image, the independent digitalization from both cameras was reconstructed with the help of a calibration volume and a 0.01). The 2D-DLT algorithm. Digitalization reliability was high (ICC=0.97 following measures were assessed: (i) swimming performance (T100); (ii) stroke parameters (stroke cycle period, stroke rate, stroke length and mean swimming velocity); (iii) estimated swimming efficiency by the swimming index; (iv) speed fluctuation (dv) and the mathematical characterization of dv. Mean dv curves normalized to time were computed with MATLAB. The polynomial regression (7th power) between dv and normalized duration of the full stroke cycle was calculated. Wilcoxon tests were performed to compare significant differences in the dependent variables (performance, stroke mechanics and efficiency variables) according to the independent variable (free versus constricted swim) (P 0.05). RESULTS: T100 was significantly higher for constricted swimming than in free condition (6.26%; Z=-2.366; P=0.02). The remaining variables showed no significant differences between the two swimming conditions. In both exercise conditions, dv was characterized by a bi-modal profile. The determination coefficients for the dv mathematical model were significant (P<0,01) and 0,47. DISCUSSION & CONCLUSION: None of the stroke mechanics and efficiency variables evaluated presented significant differences between both swimming conditions. The AquaTrainer constrictions might be related mainly to the start and turn phases. (Supported by FCT grant: POCI/DES/58362/2004)
- Physical-chemical and rheological characterization of tomato (Solanum lycopersicum L.) of AlgarvePublication . Basto De Lima, Maria Gabriela; Dias, Igor; Oliveira, Margarida; Torgal, Isabel; Faro, Maria; Matos, A.; Reis, A.The objective of this study was to evaluate the physico-chemical and rheological characteristics of two tomato varieties, Vimeiro and Runner, grown in Algarve - Portugal - in five case studies (A, B, C, D and E), during the harvest season. The samples were submitted to analysis: weight, caliber, moisture, total soluble solids, total titratable acidity, lycopene, color and hardness. When considering the factors producer X variety significant differences were observed for all parameters, excepted for color coordinates a* and H° and hardness. For weight and caliber no differences were observed between varieties. Concerning Runner variety, the producer A achieved heavier and higher caliber tomatoes compared to producer E. For total soluble solids it was verified that producer C was the one that cultivated fruits with the highest concentration for both varieties and presented a higher total titratable acidity value. These results were more evident in the Vimeiro variety. For lycopene, the highest average value was found in fruits cultivated by producer A in the Vimeiro variety. The fruits that presented the highest luminosity (L*) and higher mean values of b*, in general, were the Vimeiro variety, led by producer A. It means that the fruits have more yellowish tones than the Runner variety. The Vimeiro variety, independently of the producer, also presented higher values of C*, which means that the color of the fruits of this variety was stronger and brighter.