696 research outputs found

    The contribution of the new technologies to the 21st - Century Design

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    In the past the market economy was dominated by the local and regional design,characterized for strong links to the customs, traditions and natural resources from eachregion.As the consequence of the technological advances and the growing needs of consumption,at present, products are manufactured based on economical, functional and marketingcriterions, which means that their design is very offset from the regional and local signs.Between the challenges that characterize the actual economy, one highlights the existenceof more market niches, product variations and shorter life cycles. To survive in this economy,marked by the competition and the globalisation, one search to imply in product developingprocess, the design, engineering, marketing and production department, that composes aknown industrial methodology called concurrent or simultaneous engineering.In this article, one intends to exhibit the applications and advantages of the newtechnologies, like Rapid Prototyping (RP), that are valuable tools of the concurrentengineering and to analyse the specific implications in the design history and teaching.RP is a family of modern technologies that generate three-dimensional solid objects undercomputer control. Besides its designation be reported to the first major application that isindustrial prototyping, the RP equipments also allow the rapid tooling and the directmanufacture of small series or single products.Nowadays, the commercialisation of RP equipments, termed concept modellers or 3Dprintersis in great expansion. Although these machines use a very reduced class of cheapmaterials with poor mechanical characteristics, they allow the designers to verify and quicklytest the ideas that they are developing during the creative process. The designer can realize inplenitude the iterative process of creation without the traditional economical and materialslimitations, being enough to send the CAD file directly to the RP equipment placed in aoffice, like an usual inkjet printer. So it is possible to test new ideas with better accuracybefore its concretisation, avoiding misunderstandings and delays and inciting the positivecriticism through the involvement of the technical staff from all the related departments.Particularity, faced to the challenges due to the globalisation, the traditional and regionalindustries will find in these technologies the means that they need to ensure its own futuresurviving.This presentation is divided in the following sections:- Innovation loop in the past and in the present. The iterative process.- New technologies available to the design and the designers: Rapid Prototyping andInternet.- Design Pedagogy: new challenges in the formation of future generations of designers.- Conclusions and future trends

    Effect of competitive interactions between ectomycorrhizal and saprotrophic fungi on castanea sativa performance

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    In Northeast of Portugal the macrofungal community associated to chestnut tree (Castanea sativa Mill.) is rich and diversified. Among fungal species, the ectomycorrhizal Pisolithus tinctorius and the saprotroph Hypholoma fasciculare are common in this habitat. The aim of the present work was to assess the effect of the interaction between both fungi on growth, nutritional status and physiology of C. sativa seedlings. In pot experiments, C. sativa seedlings were inoculated with P. tinctorius and H. fasciculare individually or in combination. Inoculation with P. tinctorius stimulated the plant growth and resulted in increased foliar-N, -P, and photosynthetic pigment contents. These effects were suppressed when H. fasciculare was simultaneously applied with P. tinctorius. This result could be related to the inhibition of ectomycorrhizal fungus root colonization as a result of antagonism or to the competition for nutrient sources. If chestnut seedlings have been previously inoculated with P. tinctorius, the subsequent inoculation of H. fasciculare 30 days later did not affect root colonization and mycorrhization benefits were observed. This work confirms an antagonistic interaction between ectomycorrhizal and saprotrophic fungi with consequences on the ectomycorrhizal host physiology. Although P. tinctorius is effective in promoting growth of host trees by establishing mycorrhizae, in the presence of other fungi it may not always be able to interact with host roots due to an inability to compete with certain fungi.Authors are grateful to Fundação para a Ciência e Tecnologia (FCT) for financial support (Project PTDC/AGR-AAM/099556/2008)

    Antioxidant activities of hydroxylated naphthalenes: the role of aryloxyl radicals

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    Herein is delineated a first systematic framework for the definition of structure-antioxidant property relationships in the dihydroxynaphthalene (DHN) series. The results obtained by a combined experimental and theoretical approach revealed that 1,8-DHN is the best performing antioxidant platform, with its unique hydrogen-bonded peri-hydroxylation pattern contributing to a fast H atom transfer process. Moreover, the comparative analysis of the antioxidant properties of DHNs carried out by performing DPPH and FRAP assays and laser flash photolysis experiments, revealed the higher antioxidant power associated with an α-substitution pattern (i. e. in 1,8- and 1,6-DHN) with respect to DHNs exhibiting a β-substitution pattern (i. e. in 2,6- and 2,7-DHN). DFT calculations and isolation and characterization of the main oligomer intermediates formed during the oxidative polymerization of DHNs supported this evidence by providing unprecedented insight into the generation and fate of the intermediate naphthoxyl radicals, which emerged as the main factor governing the antioxidant activity of DHNs

    Forage production and bromatological composition of Gliricidia sepium (Jacq) Kunth ex Walp

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    Forage production and bromatologic composition of Gliricidia sepium (Jacq) Kunth ex Walp were evaluated on cattle raising serpentine soils from the Livestock Center Noel Fernández in Camagüey, Cuba. Data were processed by the statistical package SPSS, and mean and standard deviation were determined. G. sepium foliage levels were significant (3,68 kg/a/cut for green matter and 1,33 kg/a/cut for dry matter) and raw protein levels were satisfactory (13,2 %)

    Evaluation of dead leaf and soil creatures associated to Gliricidia sepium (Jacq) Kunth ex Walp, used as live fences in savannahs

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    The contribution of decayed dry leaves and edaphic fauna to soil by using Gliricidia sepium (Jacq) Kunth ex Walp as living fences on savannas  with a predominant  serpentine  stratum was determined  in Camagüey  municipality, Cuba. Results showed G. sepium beneficial environmental impact due to its high contribution of decayed dry leaves to soil, i.e., 332 kg/ha per month equivalent of 3,98 t/ha per year. Development of edaphic fauna earthworms and beetles mostly was enhanced, showing the benefits of this ecosystem environment, as well

    Efeito do teor de umidade na germinação in vitro de sementes de banana oriundas de autotetraploide induzido por duplicação dos cromossomos.

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    O processo de desidratação é um dos pontos cruciais para o sucesso da criopreservação de tecidos vegetais. Pois teores muito baixos levam à desidratação excessiva e morte das células, e aqueles elevados levam a formação de cristais de gelo no interior das células (1)
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