Browsing by Issue Date, starting with "2007"
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- Regimes Simplificados (II Parte)Publication . Aguiar, Nina; Lopes, José CarlosIn this paper, the authors analyze simplified schemes of income taxation in Italy, Germany, France and the USA. For each case, the analysis focuses on whether the tax base, by means of the simplified taxation scheme, is still formed by real income or by some other economic fact, which can work as an income proxy for taxation purposes but is not income. As simplified schemes of income taxation often consist in simplified forms of accounting for small and medium businesses, these are also analyzed and briefly compared. The authors’ main purpose is to stress the differences between simplified systems in which small taxpayers are taxed on deemed income and simplified systems in which small taxpayers are taxed on real income but are allowed to calculate their real income through a simplified method of accounting, either in its formal or substantive aspects.
- Fotografia aéreas de pequeno formato na monitorização da tinta no castanheiro no Norte de PortugalPublication . Martins, Luís; Castro, João Paulo; Macedo, FernandoA fotografia aérea de pequeno formato (FAPEF) tem-se revelado um instrumento precioso em numerosos estudos de natureza ecológica, ambiental e florestal, tanto ao nível local como regional (ZSILlNSZKY, 1970; SPENCER e HALL, 1988; DISPERATI, 1991; WARNER et al., 1996; LlLLESAND e KIEFER. 1999; MARTINS, 2004). No presente estudo ensaiamos os diversos sub-sistemas que possibilitam a FAPEF (aeronaves, sistemas de navegação e sistemas fotográficos), aplicada ao inventario epidemiológico da doença da tinta, que tem afectado numerosos castanheiros (Castanea sativa) no Norte de Portugal, causando elevados prejuízos na produção de castanha e consequentemente na economia da região.
- Desporto e género: análise das imagens de manuais escolares dos 2.º e 3.º ciclos do ensino básicoPublication . Gomes, Paula Botelho; Silva, Paula; Caetano, Silvia; Queirós, Telma Maria GonçalvesOs manuais escolares, e outros produtos pedagógicos, são recursos da actividade educativa, mediadores do processo de ensino e aprendizagem, da socialização e da formação de identidades. Segundo Brito (1999), os manuais configuram as práticas pedagógicas, disponibilizam elementos de leitura e descodificação do real, transmitem valores e normas sociais e esclarecem objectivos de aprendizagem. São ainda uma referência, dado que quem os utiliza procura uma informação exacta, importante para a construção de conhecimentos; ao estabelecer princípios e meios tidos como “verdades”, espera-se que, de facto, essas informações sejam seguidas por quem as utiliza (Castro, 1995): corpo docente, alunos/as, encarregados de educação.
- Evaluation of a numerical method to predict the polyphenol content in monovarietal olive oilsPublication . Matos, Luís C.; Pereira, J.A.; Andrade, Paula B.; Seabra, Rosa M.; Oliveira, BeatrizThree monovarietal virgin olive oils obtained from olives grown under biological agricultural system, in Portugal, with different ripening stages, were studied in what concerns the parameters usually related with oxidation status (total polyphenols, tocopherols, chlorophylls and carotenoids, peroxide values, oxidative stability, specific extinction coefficients K232 and K270 and titratable acidity). A total of 18 samples were analyzed: seven from Cv. Cobranc¸osa (maturation indices 1–7), five from Cv. Madural (maturation indices 3–7) and six from Cv. Verdeal Transmontana (maturation indices 1–6). Oxidative stability and polyphenols profile presented high correlation coef- ficients. Given this high correlation, a numerical method was developed and evaluated to predict total polyphenols contents in olive oil. The method is based on the kinetic equation of the oxidation process in the presence of antioxidants and on Rancimat profiles. Total polyphenols contents obtained with this method were similar to those obtained by the Folin-Ciocalteau method.
- Actividade física e componentes da síndrome metabólica. Um estudo em famílias açorianasPublication . Campos, Manuel Alberto Oliveira; Maia, José A.R.; Seabra, André; Silva, Rui Garganta; Lopes, Vitor P.; Freitas, Duarte L.
- Laminar flow in chevron-type plate heat exchangers: CFD analysis of tortuosity, shape factor and friction factorPublication . Fernandes, Carla S.; Dias, Ricardo P.; Nóbrega, João M.; Maia, João M.Liquid foodstuffs with high viscosity are usually processed in plate heat exchangers (PHEs) at laminar or low Reynolds numbers, Re, flows. The tortuosity coefficient is used by the manufacturers for the design and optimization of PHE geometries. Using the finite-element computational fluid dynamics program POLYFLOW®, fully developed laminar flows in double-sine chevron-type PHEs passages are analysed in this work. The corrugation angle and channel aspect ratio of the passages vary in a broad range, PHEs with common area enlargement factors and with high area density being studied. The tortuosity coefficient and the coefficient K (Kozeny´s coefficient in granular beds) from the friction factor correlations increase with the increase of the channels aspect ratio and the decrease of the chevron angle. The shape factor from the PHEs passages also increases with the decrease of the chevron angle and is weakly influenced by the channel aspect ratio. In this paper, relations to predict the tortuosity coefficient and shape factor are proposed, the coefficient K being predicted resorting to the tortuosity coefficient and shape factor. The coefficient K compares well with literature data in the region of common chevron angles, channel aspect ratio and area enlargement factor.
- Antimicrobial activity and bioactive compounds of portuguese wild edible mushrooms methanolic extractsPublication . Barros, Lillian; Calhelha, Ricardo C.; Vaz, Josiana A.; Ferreira, Isabel C.F.R.; Baptista, Paula; Estevinho, Leticia M.The antimicrobial properties of phenolic extracts of Portuguese wild edible mushroom species (Lactarius deliciosus, Sarcodon imbricatus and Tricholoma portentosum) against pathogens were investigated. The minimal inhibitory concentrations (MICs) were evaluated for the entire mushroom, the cap and the stipe, separately; the portion of the mushroom used proved to be influenced in the results obtained, which are directly correlated with the content of total phenols and flavonoids in the extracts. The growth of Grampositive bacteria (Bacillus cereus, B. subtilis,) was well inhibited by these mushrooms, while Escherichia coli (Gramnegative bacteria) was resistant. The study on the antifungal effect of these mushrooms revealed that Candida albicans and Cryptococcus neoformans were differently inhibited for the mushrooms used.
- Multicomponent sorption of hexane isomers in zeolite BETAPublication . Bárcia, Patrick da Silva; Silva, José A.C.; Rodrigues, AlírioBreakthrough curves of single, binary, ternary, and quaternary mixtures of hexane (C-6) isomers n-hexane (nHEX), 3-methylpentane (3MP), 2,3-dimethylbutane (23DMB), and 2,2-dimethylbutane (22DMB) were performed in commercial pellets of zeolite BETA (BEA structure), covering the temperature range between 423 and 523 K and partial pressures up to 30 kPa. From these data, single and multicomponent adsorption equilibrium isotherms were collected. A tri-site Langmuir model (TSL) was developed to interpret the equilibrium data based on considerations about zeolite structure, and a dynamic adsorption model was tested predicting with a good accuracy the behavior of multicomponent fixed-bed experiments. At the partial pressures studied, the sorption hierarchy in the zeolite BETA is nHEX >>> 3MP > 23DMB >> 22DMB. BEA structure demonstrates a significant selectivity between C-6 isomers, especially at low coverage, giving a good perspective regarding their separation by adsorption processes. (c) 2007 American Institute of Chemical Engineers.
- Melhoria da qualidade da habitação como estratégia de marketingPublication . Fernandes, SílviaO cliente de habitação defronta-se em Portugal com uma carência acentuada de informação sobre as características do produto que pretende adquirir, o qual acaba frequentemente por se revelar bastante diferente das suas expectativas. Essa falta de informação impossibilita-o de relacionar adequadamente a qualidade e o custo. Para além disso, os produtos de construção surgem pouco diferenciados, o que resulta da fraca abordagem do mercado por parte do sector imobiliário, dificultando o entendimento das verdadeiras necessidades e desejos dos clientes quanto ao produto, não se podendo elevar o seu valor. No mercado imobiliário altamente concorrencial em que hoje vivemos, é cada vez mais importante ponderar a qualidade da oferta, tanto mais que a decisão de investimento em habitação é das mais importantes na economia familiar dos portugueses. Sendo a concorrência fundamentada quase exclusivamente no preço, sente-se a necessidade de mudança na cultura do sector, de modo a haver uma maior focalização no cliente final, adoptando-se para isso estratégias de marketing e de qualidade. Este trabalho tem como objectivo criar um modelo de apoio às empresas construtoras/promotoras, no sentido de obter informações dos seus clientes em fase de utilização, de modo a que a sua gestão permita elevar o valor dos seus produtos/serviços, e por sua vez a competitividade no sector. O modelo foi desenvolvido na cidade de Bragança, com base num questionário aplicado a clientes de habitação, integradas em 14 edifícios multifamiliares, construídos por quatro empresas construtoras/promotoras. Prospective housing clients in Portugal face up a marked lack of information on the characteristics of the housing product they intend to buy, which most often turns out to be very different of their expectations. This lack of information does not allow them to relate adequately quality and cost. Furthermore, housing products are not adequately differentiated owing to an inefficient approach to the market from the part of the property sector, which makes difficult the understanding of the true needs and wishes of the client regarding the housing product. Nowadays, in a highly competitive housing market, it is increasingly needed to weigh the quality of supply, for housing investment is one of the most important decisions of the Portuguese households. Due to the fact that competition on that market is almost exclusively based on price, there is a need for change in the culture of the housing sector that would promote adequate strategies of marketing and quality. This research project has as the main aim to develop a support tool for the construction enterprises of the housing sector in order to improve the value of their products/services and, to a certain extent, the competitiveness of the sector. The model, which is specifically developed for the town of Bragança, is based on information collected from housing c1ients in the occupancy stage. It was done through the use of a questionnaire- survey conducted on respondents from fourteen multi-family housing, which were built by four contractors/developers.
- Bioactive properties of the medicinal mushroom Leucopaxillus giganteus mycelium obtained in the presence of different nitrogen sourcesPublication . Barros, Lillian; Baptista, Paula; Estevinho, Leticia M.; Ferreira, Isabel C.F.R.Leucopaxillus mushroom species are used in the chemical industry for extraction of clitocybin antibiotic and particularly the edible mushroom Leucopaxillus giganteus can be found in Northeast Portugal. Nevertheless, the production of its mycelium for pharmacological applications has not been explored. Herein, the mycelium obtained in the presence of four different nitrogen sources was investigated with regard to phenol production and antimicrobial and antioxidant properties. Phenol concentration increased along the growth time as a response to the oxidative stress and therefore free radical production. Although significant differences for mycelium growth between the nitrogen sources had not been observed, (NH4)2HPO4 proved to be the most appropriate to increase bioactive properties, leading to the highest phenol content and lowest EC50 and MIC values. The antimicrobial capacity was screened against Gram positive and Gram negative bacteria, and fungi. The samples selectively inhibited the growth of Gram positive bacteria, Staphylococcus aureus being the most susceptible one. Gram negative bacteria and fungi were resistant to the extracts. Antioxidant activity was calculated by the reducing power assay, the scavenging effect on DPPH radicals, and hemolysis and lipid peroxidation inhibition. Significantly negative linear regressions were established between phenols/flavonoids contents, which increased along the mycelia growth time and antioxidant activity.