Light harvesting in solar cells using natural pigments from red fruits adsorbed to mesoporous TiO2

Nature has developed strategies to present us with a wide variety of colours, from the green of leaves to the bright colours seen in flowers. Anthocyanins are between these natural pigments that are responsible for the great diversity of colours seen in flowers and fruits. Anthocyanins have been used to sensitize titanium dioxide (TiO2) in Dye-Sensitized Solar Cells (DSSCs). DSSCs have become one of the most popular research topic in photovoltaic cells due to their low production costs when compared to other alternatives. DSSCs are inspired in what happens in nature during photosynthesis. A primary charge separation is achieved by means of a photoexcited dye capable of performing the electron injection into the conduction band of a wide band-gap semiconductor, usually TiO2. With this work we aimed to synthesize a novel mesoporous TiO2 structure as the semiconductor in order to increase the dye loading. We used natural occurring dyes such as anthocyanins and their synthetic flavylium relatives, as an alternative to the widely used metal complexes of Ru(II) which are expensive and are environmentally unsafe. This offers not only the chance to use safer dyes for DSSCs, but also to take profit of waste biological products, such as wine and olive oil production residues that are heavily loaded with anthocyanin dyes. We also performed a photodegradation study using TiO2 as the catalyst to degrade dye contaminants, such as those from the wine production waste, by photo-irradiation of the system in the visible region of the light spectrum. We were able to succeed in the synthesis of mesoporous TiO2 both powder and thin film, with a high capacity to load a large amount of dye. We proved the concept of photodegradation using TiO2 as catalyst. And finally, we show that wine production waste is a possible dye source to DSSCs application.

m-SportGIS

Information technologies (ITs), and sports resources and services aid the potential to transform governmental organizations, and play an important role in contributing to sustainable communities development, respectively. Spatial data is a crucial source to support sports planning and management. Low-cost mobile geospatial tools bring productive and accurate data collection, and their use combining a handy and customized graphical user interface (GUI) (forms, mapping, media support) is still in an early stage. Recognizing the benefits — efficiency, effectiveness, proximity to citizens — that Mozambican Minister of Youth and Sports (MJD) can achieve with information resulted from the employment of a low-cost data collection platform, this project presents the development of a mobile mapping application (app) — m-SportGIS — under Open Source (OS) technologies and a customized evolutionary software methodology. The app development embraced the combination of mobile web technologies and Application Programming Interfaces (APIs) (e.g. Sencha Touch (ST), Apache Cordova, OpenLayers) to deploy a native-to-the-device (Android operating system) product, taking advantage of device’s capabilities (e.g. File system, Geolocation, Camera). In addition to an integrated Web Map Service (WMS), was created a local and customized Tile Map Service (TMS) to serve up cached data, regarding the IT infrastructures limitations in several Mozambican regions. m-SportGIS is currently being exploited by Mozambican Government staff to inventory all kind of sports facilities, which resulted and stored data feeds a WebGIS platform to manage Mozambican sports resources.

Os livros de viagens medievais

Quando tomados no seu todo, os livros de viagens medievais formam um género multifacetado. São obras de carácter diverso, que têm na sua base propósitos igualmente diferenciados. No entanto, ainda que de forma variável e sem qualquer padrão estabelecido, o recurso comum a um conjunto de procedimentos narrativos garante aos textos que compõem este género diversificado uma forma literária autónoma no panorama da prosa medieva. Uma forma literária que, na essência, oferece uma visão bastante clara da concepção do mundo e da realidade na Idade Média, ao mesmo tempo que constitui uma fonte incontornável para compreender aspectos muito diversos da cultura medieval.