Experimental and Numerical Studies on a Centrifugal Pump with 2D-Curved Blades in Cavitating Condition

In the presented study a special test-pump with 2D curvature blade geometry in cavitating and non-cavitating conditions was investigated using different experimental techniques and a 3D numerical model of cavitating flows. Experimental and numerical results concerning pump characteristics and performance breakdown were compared at different flow conditions. Appearing types of cavitation and the spatial distribution of vapour structures within the runner were also analysed

DETERMINATION OF WAVE RUN-UP THROUGH THE TIMESTACK METHODOLOGY AND THROUGH A RESISTIVE WAVE GAUGE. A COMPARATIVE ANALYSIS

The objective of this work is the comparison of two methodologies used for run-up measurements in a two-dimensional physical model, which represented the protection breakwaters of the Peniche and Ericeira’s ports. Tests were carried out in the scope of the BSafe4sea project. The methodologies used were: a) the traditional measurement of the run-up height with a resistive wave gauge; b) the use of video cameras and image processing techniques images to infer the run-up heights, having its performance evaluated for some of the test conditions. Regarding the results obtained, in terms of Ru2% and Rumax, it was found that the magnitude of the values obtained with the two techniques were quite similar, although the video analysis returned slightly higher values than the wave gauge. Thus, it was found that the video image technique is a viable alternative to measure the run-up. It is recommended the use of diffused light during the tests, along with stabilizing the video camera, to improve the accuracy of the results obtained by the video-based  technique. Besides, the quality of the video image and the use different colors of the armour units of the phicial model, could contribute to achieve better results with the TimeStack methodology

Effect of sewage sludge on the incidence of corn stalk rot caused by Fusarium.

During the last decades, sewage started to be treated in order to reduce the pollution of rivers, resulting in the production of a sludge rich in organic matter and nutrients, called sewage sludge. Among the alternatives for final discarding, the agricultural use is one of the most convenient, because it combines disposal and recycling. However, using sewage sludge as a fertilizer causes alterations in the physical, chemical and biological properties of the soils. The soilborne plant pathogens are highly influenced by the way the soil is managed; thus, sewage sludge may interfere with the occurrence of diseases caused by these microorganisms. The objective of this study was to evaluate the effect of sewage sludge on corn stalk rot, caused by Fusarium spp

Protocolo para produção de material propagativo de batata em meio líquido.

Os meios semi-sólidos são os mais utilizados em trabalhos de micropropagação, mas há indícios de que o estado físico dos meios de cultura influencia a multiplicação dos cultivos. O objetivo deste trabalho foi estabelecer um protocolo para a multiplicação de material propagativo de batata em meio de cultura líquido. Explantes de batata da cultivar Eliza, com uma gema axilar, foram cultivados em seis diferentes meios de cultura, com (semi-sólido) ou sem (líquido) a adição do solidificante ágar. Após 21 dias de cultivo, o meio de cultura que proporcionou os melhores resultados para crescimento e taxa de multiplicação teve sua composição modificada com o objetivo de melhorar a eficiência de multiplicação de cinco cultivares em meio líquido. Foi também avaliada a necessidade de agitação dos cultivos em meio líquido. Houve ganho na eficiência de multiplicação in vitro da batata, quando se utiliza meio de cultura líquido. Os melhores resultados são obtidos quando o material é cultivado em meio constituído pelos sais de MS na concentração plena, acrescido de ácido pantotênico (5,0 mg L-1), tiamina (1,0 mg L-1), ácido giberélico (0,25 mg L-1) e sacarose (20 g L-1), sob agitação constante