Browsing by Issue Date, starting with "1995"
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- Factors affecting rind pitting in the mandarin hybrids "fortune" and "nova". The influence of exogenous growth regulatorsPublication . Duarte, Amílcar; Guardiola, J. L.The commercialization of the mandarin hybrids "Fortune" and "Nova" is hindered by the development of cold-induced pitting in the fruit rind which may develop either in the orchard or during storage and transport. In the late cropping cultivar "Fortune", the pitting develops on tree during the winter months and affects mainly the exposed fruit from the north-west quadrant of the tree. The induction of symptoms under uniform conditions in the cold-room reveals differences in the susceptibility to chilling injury among the fruits and the fruit sides. The green fruit is not susceptible. Susceptibility develops as pigmentation progresses, and it is higher for the exposed than for the non-exposed (covered by the foliage) fruits. The application of GA3 at colour-break delays pigmentation and retards the development of susceptibility. The waxing of the fruit offers some protection to cold in the cold-room. However, the incidence of pitting is not related to the wax content of the fruit rind and the application of a wax coverage on tree had only a marginal protective effect. No pitting is usually found on tree in the fruit of the early ripening "Nova" cultivar, which is usually harvested before the winter chilling. The pitting develops during cold storage (8-10 C), and is reduced by GA3 application at colour break, an effect related to the delay in rind pigmentation.
- On bottom properties estimation from towed array dataPublication . Jesus, S. M.; Jesus, M. C.Estimating seabottom structure from the analysis of acoustic returns of an explosive source (air-gun, sparker...) has been used for a long time as a routine survey technique. Recent work showed the possibility of using well-suited numerical numbers to invert the acoustic field for inverting detalied sedimental physical properties.
- A neural network PID autotunerPublication . Ruano, Antonio; Lima, João; Mamat, R.; Fleming, P. J.Proportional, Integral and Derivative (PID) regulators are standard building blocks for industrial automation. Their popularity comes from their rebust performance and also from their functional simplicity. Whether because the plant is time-varying, or because of components ageing, these controllers need to be regularly retuned.
- Estudo da utilizaçäo dos glúcidos em dietas para robalo (Dicentrarchus labrax)Publication . Raposo, Maria Albertina; Wallace, Jeffrey; Gomes, EmídioEm teleósteos, a investigação para conhecimento do metabolismo e das necessidades metabólicas é de grande interesse por forma a produzirmos a melhor dieta ao mais baixo custo. Entre as espécies marinhas com potencialidades de produção encontra-se o robalo {Dicenírarchus labrax). No presente trabalho, fornecemos a três grupos de animais dietas isoenergéticas, isoproteicas e isolipídicas em que fizémos variar a fonte dos carbohidratos utilizando amido de batata cru (dieta AC), amido de batata gelatinizado (dieta AG) e amido de trigo micronizado (dieta TM). Comparámos os crescimentos obtidos e acompanhámos a evolução pós-prandial durante 24 horas dos metabolitos glucose e ácidos aminados livres totais no plasma e glicogénio hepático no fígado. Os nossos resultados parecem indicar a não influência do estado físico do amido no metabolismo da nutrição em robalo e a aceitação de alguma quantidade de carbohidratos na dieta por esta espécie. Porém, novos ensaios são necessários por forma a optimizar as condições de crescimento, por um lado e a determinar outros metabolitos e hormonas que possam estar relacionados com o metabolismo intermediário dos carbohidratos, por outro.
- Pedagogia da comuniçao, cinema e ensino: dimensoes pedagógicas do cinemaPublication . Reia-Baptista, VítorA inclusão de estudos mediáticos nos di- ferentes níveis de ensino é uma medida ne- cessária para uma formação integral e ade- quada às características culturais do cidadão das sociedades modernas onde o fenómeno comunicativo global assume grande impor- tância social, cultural e pedagógica. Neste contexto, em que o cinema se inte- gra perfeitamente, o estudo da dimensão pe- dagógica dos fenómenos fílmicos e cinemá- ticos torna-se um acto de aquisição de conhe- cimentos e de reflexão crítica sobre uma fa- ceta preponderante da nossa história cultural recente, ou seja, destes últimos cem anos em que a humanidade tem deixado as suas mar- cas narrativas e multiculturais em imagens e sons interligados de formas várias.
- 3-Hydroxy-2,6-dinitroacetophenone: an unusual substitution pattern resulting from nitration of 3-hydroxyacetophenonePublication . Cristiano, Maria Lurdes Santos; Johnstone, Robert A. W.; Pratt, M. J.Nitration of 3-hydroxyacetophenone gives 2,6-dinitro-3-hydroxyacetophenone, C8H6N206, in which the nitro groups have entered the sterically least favourable positions in the aromatic nucleus. None of the expected substitution in the 4-position was observed. The two nitro groups flanking the carbonyl side chain are different in that one is in the plane of the aryl ring but the other is twisted well out of the plane.
- Geophysical seafloor exploration with a towed array in shallow waterPublication . Caiti, A.; Jesus, S. M.The quantitative measurement or estimation of the geophysical properties of the seafloor upper sedimentary strata is a requirement in several marine applications, from geotechnical engineering to underwater acoustics. Traditional methods employ in-situ instrumentation (cone penetrometers, coring, etc.) and are able to probe the seafloor at selected points. This project aims at exploring the feasibility of seafloor model identification by acoustic means. In particular, the project has considered the use of an acoustic system, in which a ship tows both an acoustic source and an horizontal array of receivers. From the acoustic field measured at the receiving array, the seafloor parameters are estimated by suitable inversion algorithms. The project focused in particular on the use of such a system in shallow waters, and considered the advantages and limitations of the method from the point of view of system requirementes, signal processing and inversion strategies. Sensitivity studies show that it is indeed possible to recover the seafloor parameters in shallow water with a moderate aperture towed array, and experimental results are shown to demonstrate the feasibility of the concept. Possible improvements and further lines of research are also discussed.
- A População em 1835 e 1843/48 na vila de LouléPublication . Mesquita, José Carlos VilhenaEste estudo integra-se no âmbito da Demografia Histórica, tendo como palco a população na vila de Loulé, Algarve. O espaço cronológico em que decorre a investigação incide em dois momentos fulcrais do oitocentismo português: o fim das Lutas Liberais e a reorganização do tecido social segundo a nova ordem política, tendo como data de apreciação o ano de 1835; e o período decorrente do governo "cabralista" de Costa Cabral que viria a suscitar a revolução da "Maria da Fonte" e a consequente guerra civil da "Patuleia", tendo como período de apreciação e análise crítica os anos de 1843 até 1848. Os aspectos sociológicos da urbe louletana, a sua distribuição socioeconómica, os novos elencos políticos, a produção industrial, o casco urbano, os índices de crescimento populacional, são, entre vários outros aspectos, o fulcro deste trabalho.
- Structural-semantic principles of formation of the types of the folk talePublication . Kerbelyte, BronislavaThe A. Arne - S. Thompson system of classification of folk tales is convenient for distinguishing relatively stable plot formations characteristics of the late period in the development of national traditions.
- Internationalisation processes in small and medium enterprises of the agrifood sector in PortugalPublication . Noronha, Teresa deDuring thel ast years we have observedin Portugal;as in the mosto f the European countriesa, n accentuated development concerning the internationalisation of the agri-food sector. As a result a better cornpetitive capacity is expected together with the technological reconversion of Portuguese enterprises, an improved organisational capacity of their managers as well as agressivity in the external markets. The internationalisation of enterprises, particularly of small and medium enterprises, may cause the development of their strategic capacity. The, agrifood sector is analyzed using four main topics: the recent evolution of the sector, the growth of the agiifood industry, the relative importanoe of the internationalisation process and the entrepreneurial and governemental strategies for internationalisation. The study allows to open the discussion on the importance that foreign capital has in the Portuguese SMEs atid in the exports value of the Portuguese agri-food sector, considering some subsectors in particular. We are able to conclude that therei s a growing interest of the agrifood European industriyn the Portuguese SMEs, speciallyi n those producing for the internal market. Further, conclusions coulbde arrived at regarding the growing capacitoy f a few large enterprisest o export parallelt o a decreasing participation of the "traditional" SMEs. They need to enter reconversion processesin order to improve specificities of the producatn d find niche markets.