114 documents found, page 1 of 12

Stream sediments geochemistry on the Valongo anticlinal, northern Portugal: Ars...

The Valongo anticline is known for the occurrence of several Sb-Au and As-Au mineral deposits, many of which have been exploited since Roman times. The Sb-Au and As-Au deposits occur in brecciated quartz veins, predominantly trending NE-SW, NNW-SSE, and ENE-WSW, cutting Cambrian to Carboniferous formations. An 801-stream sediment campaign was conducted in this area. Factorial kriging was applied as an interpola...

Effect of high solids loading on gasliquid mass transfer in an oscillatory flow...

A wide range of chemical processes involves three phases, where common systems have inefficient mixing and mass transfer is limited. This study uses the oscillatory flow reactor with smooth periodic constrictions (OFR-SPC) according to the patent EP3057694 (B1) to evaluate its potential on O2 mass transfer at high solids loading (1050 % (v/v)). For that, the effect of solids (EPS, PVC) properties (concentration...

Stream sediments geochemistry in the Valongo anticline, northern Portugal: Arse...

O anticlinal de Valongo é conhecido pela ocorrência de vários depósitos minerais de Sb-Au e As-Au, muitos deles explorados desde os tempos romanos. Os depósitos de Sb-Au e As-Au ocorrem nos filões de quartzo com estrutura brechóide com direção predominante NE-SW, NNW-SSE, e ENE-WSW cortando formações do Câmbrico ao Carbónico. Uma campanha de 801 sedimentos de corrente foi obtida nesta área. A krigagem factorial...

Hydrodynamics and gas-liquid mass transfer in an oscillatory flow reactor: infl...

Liquid properties, such as, surface tension and viscosity are important parameters as they control gas-liquid mass transfer in bioprocesses. An oscillatory flow reactor provided with smooth periodic constrictions (OFR-SPC) was considered to evaluate its potential for mass transfer performance in non-pure gas-liquid systems. The effect of surface tension and viscosity on the volumetric (kLa) and liquid-side mass...

Silurian black shales from Sousel-Barrancos Metallogenic Belt (Ossa-Morena Zone...

Black shales are commonly spatially associated with metal-rich deposits, wherein organic matter in these rocks may condition or influence the processes related with the concentration of metals and formation of ore deposits. In the Ossa-Morena Zone (South of Portugal), namely in the Sousel-Barrancos metallogenic belt, several Cu mineralized veins occurs, being generally hosted in Silurian metasedimentary units m...

Do chão do Alto Minho: Uma investigação-ação sobre arte, educação e território

The effect of handlebar height and bicycle frame length on muscular activity du...

The cycling literature is filled with reports of electromyography (EMG) analyses for a better understanding of muscle function during cycling. This research is not just limited to performance, as the cyclist’s goal may be rehabilitation, recreation, or competition, so a bicycle that meets the rider’s needs is essential for a more efficient muscular activity. Therefore, the purpose of this study was to understan...

The influence of electrolytes in aqueous solutions on gas-liquid mass transfer ...

In bioprocesses, the microorganisms growth is ruled by physical, chemical, and biological conditions being the electrolyte concentration one of the most important parameters to control. In this study, the effect of three electrolytes (HCl, NaOH, NaCl) in aqueous solutions on the volumetric (kLa) and liquid-side (kL) mass transfer coefficients and bubbles dynamics in an oscillatory flow reactor provided with smo...

Desafios BIM na implementação do plano geral de drenagem de Lisboa

Com a finalidade de mitigar as consequências provocadas pelas graves inundações que têm fustigado Lisboa devido a eventos pluviais extremos, a Câmara Municipal de Lisboa promoveu a sua maior obra dos últimos 100 anos, a empreitada de execução dos túneis de drenagem da cidade de Lisboa e intervenções associadas. Sendo uma obra geotécnica complexa e audaciosa, projetada para um período de vida útil mínimo de 100 ...

Exploring the potential of cuttlebone waste to produce building lime

The goal of this study is to find a practicable way to recycle cuttlebone waste in the production of lime. It was studied the behavior of calcium oxide obtained from the calcination of this waste at 900, 1000 and 1100 ºC and, after wet slaking, the produced lime was characterized. All the results were compared to calcium oxide or to hydrated lime obtained from commercial limestone. According to the slaking resu...