The future of power systems: Challenges, trends, and upcoming paradigms

The decarbonization of the economy, for which the contribution of power systems is significant, is a growing trend in Europe and in the world. In order to achieve the Paris Agreement's ambitious environmental goals, a substantial increase in the contribution of renewable sources to the energy generation mix is required. This trend brings about relevant challenges as the integration of this type of sources increases, namely in terms of the distribution system operation. In this paper, the challenges foreseen for future power systems are identified and the most effective approaches to deal with them are reviewed. The strategies include the development of Smart Grid technologies (meters, sensors, and actuators) coupled with computational intelligence that act as new sources of data, as well as the connection of distributed energy resources to distribution grids, encompassing the deployment of distributed generation and storage systems and the dissemination of electric vehicles. The impact of these changes in the distribution system as a whole is evaluated from a technical and environmental perspective. In addition, a review of management and control architectures designed for distribution systems is conducted. This article is categorized under: Energy Infrastructure > Systems and Infrastructure Energy Infrastructure > Economics and Policy.ERDF - European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation - COMPETE 2020 Programme, and by National Funds through the Portuguese funding agency, FCT - Fundacao para a Ciencia e a Tecnologia, Grant/Award Number: SAICTPAC/0004/2015-POCI-01-0145-FEDER-01643

Nutrients, phytochemicals and bioactivity of wild Roman chamomile: a comparison between the herb and its preparations

Roman chamomile, Chamaemelum nobile L. (Asteraceae), has been used for medicinal applications, mainly through oral dosage forms (decoctions and infusions). Herein, the nutritional characterisation of C. nobile was performed, and herbal material and its decoction and infusion were submitted to an analysis of phytochemicals and bioactivity evaluation. The antioxidant activity was determined by free radicals scavenging activity, reducing power and inhibition of lipid peroxidation, the antitumour potential was tested in human tumour cell lines (breast, lung, colon, cervical and hepatocellular carcinomas), and the hepatotoxicity was evaluated using a porcine liver primary cell culture. C. nobile proved to be an equilibrated valuable herb rich in carbohydrates and proteins, and poor in fat, providing tocopherols, carotenoids and essential fatty acids (C18:2n6 and C18:3n3). Moreover, the herb and its infusion are a source of phenolic compounds (flavonoids such as flavonols and flavones, phenolic acids and derivatives) and organic acids (oxalic, quinic, malic, citric and fumaric acids) that showed antioxidant and antitumour activities, without hepatotoxicity. The most abundant compounds in the plant extract and infusion were 5-O-caffeoylquinic acid and an apigenin derivative. These, as well as other bioactive compounds, are affected in C. nobile decoction, leading to a lower antioxidant potential and absence of antitumour potential. The plant bioactivity could be explored in the medicine, food, and cosmetic industries.The authors are grateful to strategic project PEst-OE/AGR/UI0690/2011 for financial support to CIMO. R. Guimaraes, L. Barros and R. Calhelha thanks to FCT, POPH-QREN and FSE for their Grants (SFRH/BD/78307/2011, SFRH/BPD/4609/2008 and SFRH/BPD/68344/2010). The GIP-USAL is financially supported by the Consolider-Ingenio 2010 Programme (FUN-C-FOOD, CSD2007-00063). M. Duenas thanks the Spanish "Ramon y Cajal" Programme for a contract

Métrica Induzida da Correntropia Complexa Comparada ao NESTA no Problema de Amostragem Compressiva / Induced Complex Correntropy Metric Compared to NESTA on the Compressive Sampling Problem

Esse artigo compara ao algoritmo de Nesterov (NESTA) o desempenho da métrica induzida da correntropia complexa (Complex Correntropy Induced Metric - CCIM) enquanto uma aproximação de l0 num problema de amostragem compressiva. As simulações mostram que a CCIM é capaz de reconstruir um vetor esparso complexo usando menos medidas do que o NEST

Extração de Características Cicloestacionárias por Correntropia Cíclica em Canais com Desvanecimento / Extraction of Cystationary Characteristics by Cyclic Correntropy in Fading Channels

A Função de Correntropia Cíclica (CCF - Cyclic Correntropy Function) vem sendo aplicada em diferentes problemas na área de processamento de sinais para comunicações, por exemplo, detecção espectral, estimativa de parâmetros de sinais e classificação automática de modulações. Entretanto, os modelos para os canais de comunicações considerados na maioria desses trabalhos incorporam apenas os efeitos do ruído aditivo gaussiano, ou impulsivo. Neste trabalho, investiga-se o desempenho da CCF na extração de características de sinais para fins de classificação automática de modulações em cenários de comunicações nos quais os sinais se propagam por múltiplos percursos, ficando sujeitos aos efeitos do desvanecimento Rayleigh plano. Os resultados demonstram que a CCF também pode levar a bons resultados nesses ambientes de comunicações