Beach and cliff retreat induced by storm groups at Forte Novo,Algarve (Portugal)

Littoral cell dynamics may change through time as a reaction to modifications of the coastal system. Along the Vilamoura-Quarteira coastline, the construction of a groin field limited the sediment supply to the already narrow Forte Novo beach, located downdrift, enhanced wave action on the cliff base and lead to long-term persistent cliff retreat. This research uses a set of surveys from November 2009 to March 2010 to determine short-term soft cliff erosion associated to storm groups at this sediment starved area. Following the initial LiDAR survey, three subsequent surveys were performed using a reflectorless total station for monitoring the cliff face, and RTK-DGPS to monitor the position of the cliff top, the cliff foot and the topography of the adjacent beach. Results indicate an important reduction in beach levels during successive storms (without significant beach recovery in between), allowing waves to further attack the cliff base and contributing to further enhance the structural and permanent cliff retreat. This work demonstrates how a combination of magnitude and frequency of extreme events coupled with development of the coastline, has led to increased cliff-beach recession and to the permanent dislocation of the cliff face

Arsenic in rice agrosystems (water, soil and rice plants) in Guayas and Los Rios provinces, Ecuador

Geogenic arsenic (As) can accumulate and reach high concentrations in rice grains, thus representing a potential threat to human health. Ecuador is one of the main consumers of rice in South America. However, there is no information available about the concentrations of As in rice agrosystems, although some water bodies are known to contain high levels of the element. We carried out extensive sampling of water, soil, rice plants and commercial rice (obtained from local markets). Water samples were analysed to determine physico-chemical properties and concentrations of dissolved arsenic. Soil samples were analysed to determine total organic C, texture, total Fe and amorphous Fe oxyhydroxides (Fe-ox), total arsenic (tAs) and the bioavailable fraction (As-Me). The different plant parts were analysed separately to determine total (tAs), inorganic (iAs) and organic arsenic (oAs). Low concentrations of arsenic were found in samples of water (generally 80%) in all parts of the rice plants. (C) 2016 Elsevier B.V. All rights reserved

Synthesis and properties of Co-doped titanate nanotubes and their optical sensitization with methylene blue

Here we report on a novel chemical route to synthesize homogenous cobalt doped titanate nanotubes (CoTNT), using an amorphous Co-doped precursor. The influence of the synthesis temperature, autoclave dwell time and metal doping on the structural and microstructural as well as on the optical properties of the synthesized titanate nanotubes is studied and discussed. The optical band gaps of the CoTNT samples are red shifted in comparison with the values determined for the undoped samples, such red shifts bringing the absorption edge of the CoTNT samples into the visible region. CoTNT materials also demonstrate particular high adsorption ability for methylene blue, the amount of the adsorbed dye being higher than the one predictable for a monolayer formation. This suggests the possibility of intercalation of the dye molecule between the TiO6 layers of the TNT structure. It is also shown that the methylene blue sensitized Co-doped nanostructures are highly stable under UV radiation and present a strong and broad absorption in the visible region.Comment: 31 pages, 3 tables, 7 figure

Hymenoptera pollinator effect on environment

There are several studies reporting the evidence that pollinators are declining as a result of local and global environmental degradation. Operation Pollinator is an international biodiversity program, supported by Syngenta, to boost the number of pollinating insects on commercial farms. It works by creating specific habitats, tailored to local conditions and native insects. The aim of this work is to increase the ecological suitability of pollinator populations through improves food availability for pollinator employing strategies for surrounding landscape. Two cherry orchards, located in Fundão, Portugal, were studied: one was installed a patch meadow with flowery prairie with the purpose of increasing pollinator’s number; other with poor native biodiversity. It was identified the main groups of insects visiting the cherry blossoms and the surrounding flora, during the flowering cherry trees. This review was conducted through observation and analysis of pollen in pollinator’s nests, artificially placed in the orchards in order to evaluate the visiting flowers. There was a greater number of pollinating insects in the orchard with higher biodiversity and it was found that insects visited other flora along with the cherry blossoms. The Hymenoptera identified belong to genus: Andrena; Apis; Eucera; Tropinota; Anthophora; Osmia; Xylocopa. The orchard where haven’t been installed the patch meadow, shows a lower number of visiting insects as well as lower species variability. The increasing of pollinators protects the environment and increases the fruit production and quality. The findings of the sweeter fruit, with the increased number and diversity of insects leads to the conclusion that the environment benefits from the increase in pollinators with more balanced environment, it's a winning environment for everyone. The conservation of pollinator habitat can also enrich overall biodiversity and the ecosystem services, protect soil and water qualityinfo:eu-repo/semantics/publishedVersio

The Variable Polarity Plasma Arc Welding Process: Its Application to the Space Shuttle External Tank

This report describes progress in the implementation of the Variable Polarity Plasma Arc Welding (VPPAW) process at the External Tank (ET) assembly facility. Design allowable data has been developed for thicknesses up to 1.00 in. More than 24,000 in. of welding on liquid oxygen and liquid hydrogen cylinders has been made without an internal defect