3 resultados para 657

em Instituto Politécnico do Porto, Portugal


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Centrando-se no capital social, esta obra pretende ser uma reflexão sobre os aspetos mais significativos do regime económico das cooperativas no Direito Português: o regime jurídico das entradas para o capital social nas cooperativas, o confronto entre aquelas e a chamada «massa de gestão económica», a determinação e distribuição de resultados, as funções do capital e das reservas, nomeadamente as reservas obrigatórias, e a problemática do aumento e redução do capital social cooperativo. Além disso, tendo como assente que a questão do capital diz respeito aos fundamentos do sistema económico cooperativo, procuraram-se respostas jurídicas adequadas para alguns dos problemas que o regime económico das cooperativas coloca no ordenamento português, muitos deles resultantes das características do capital social cooperativo, designadamente do seu carácter variável. Nesta procura faz-se o confronto entre a legislação cooperativa portuguesa e outras legislações de cooperativas, com particular destaque para a italiana, a espanhola, a francesa e a comunitária, para ilustrar outras soluções e, igualmente, para reflectir e propor alterações normativas à legislação positiva portuguesa, o que confere utilidade à obra, que interessará não apenas a juristas, mas também a todos os cooperativistas.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

With the electricity market liberalization, the distribution and retail companies are looking for better market strategies based on adequate information upon the consumption patterns of its electricity consumers. A fair insight on the consumers’ behavior will permit the definition of specific contract aspects based on the different consumption patterns. In order to form the different consumers’ classes, and find a set of representative consumption patterns we use electricity consumption data from a utility client’s database and two approaches: Two-step clustering algorithm and the WEACS approach based on evidence accumulation (EAC) for combining partitions in a clustering ensemble. While EAC uses a voting mechanism to produce a co-association matrix based on the pairwise associations obtained from N partitions and where each partition has equal weight in the combination process, the WEACS approach uses subsampling and weights differently the partitions. As a complementary step to the WEACS approach, we combine the partitions obtained in the WEACS approach with the ALL clustering ensemble construction method and we use the Ward Link algorithm to obtain the final data partition. The characterization of the obtained consumers’ clusters was performed using the C5.0 classification algorithm. Experiment results showed that the WEACS approach leads to better results than many other clustering approaches.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The interest for environmental fate assessment of chiral pharmaceuticals is increasing and enantioselective analytical methods are mandatory. This study presents an enantioselective analytical method for the quantification of seven pairs of enantiomers of pharmaceuticals and a pair of a metabolite. The selected chiral pharmaceuticals belong to three different therapeutic classes, namely selective serotonin reuptake inhibitors (venlafaxine, fluoxetine and its metabolite norfluoxetine), beta-blockers (alprenolol, bisoprolol, metoprolol, propranolol) and a beta2-adrenergic agonist (salbutamol). The analytical method was based on solid phase extraction followed by liquid chromatography tandem mass spectrometry with a triple quadrupole analyser. Briefly, Oasis® MCX cartridges were used to preconcentrate 250 mL of water samples and the reconstituted extracts were analysed with a Chirobiotic™ V under reversed mode. The effluent of a laboratory-scale aerobic granular sludge sequencing batch reactor (AGS-SBR) was used to validate the method. Linearity (r2 > 0.99), selectivity and sensitivity were achieved in the range of 20–400 ng L−1 for all enantiomers, except for norfluoxetine enantiomers which range covered 30–400 ng L−1. The method detection limits were between 0.65 and 11.5 ng L−1 and the method quantification limits were between 1.98 and 19.7 ng L−1. The identity of all enantiomers was confirmed using two MS/MS transitions and its ion ratios, according to European Commission Decision 2002/657/EC. This method was successfully applied to evaluate effluents of wastewater treatment plants (WWTP) in Portugal. Venlafaxine and fluoxetine were quantified as non-racemic mixtures (enantiomeric fraction ≠ 0.5). The enantioselective validated method was able to monitor chiral pharmaceuticals in WWTP effluents and has potential to assess the enantioselective biodegradation in bioreactors. Further application in environmental matrices as surface and estuarine waters can be exploited.