Indirect rapid tooling with aluminium and milled fibre reinforced resins

It is well known that Rapid Prototyping (RP) and Rapid Tooling (RT) are fundamental technologies to reduce the time tomarket and consequently increase productivity and competitiveness of companies working in different industrial sectors.RT with epoxy resins is presently accepted as an established process of indirect rapid tooling. However, patents,processing difficulties and companies limitations disable a wider implementation of this technology.This paper presents the experimental results of a detailed work, conducted at INEGI, to manufacture moulds for plasticinjection, with tailored properties, using RP models and aluminium filled and fibres reinforced epoxy resins

The effect of aluminium granulometry on the behaviour of filled epoxy resins for rapid tooling

Aluminium filled epoxies moulds have beenused in indirect rapid tooling. These moulds, whichhave a low cost processing, are very competitive,when applied in the manufacturing of low volumeseries.The geometry and the size distribution of thealuminium particles affect significantly the powderpacking density, the resin ratio, the thermalconductivity, the curing time, the homogeneity andthe mechanical characteristics of the tool.Using three high temperature epoxy resins itwas possible to understand the resin behaviour inthe presence of the aluminium filler and formulatefilled resins with the best compromise ofmechanical, thermal and processing performance

Endo- and epiphytic fungal communities of olive twigs is influenced by cultivar and olive knot infection

Olive tree phyllosphere is colonized by a diverse microbial assemblage that may interact with pathogenic fungi, making them potential candidates for disease supression. Olive knot (OK) is a disease caused by the bacterium Pseudomonas savastanoi pv. savastanoi (Psv.) with significant economic losses in olive tree (Olea europaea L.). With this work we want to evaluate the effect of cultivar and OK infection on both endo- and epiphytic fungal community inhabiting olive twig tissues. For this, fungal composition and diversity was assessed in both asymptomatic and OK-symptomatic twigs of tree co-occurring olive cultivars with different susceptibilities to OK disease. The identification of isolated species was performed by ITS rDNA sequencing. The cultivar and OK infection were important in shaping both endophytic and epiphytic fungal communities. Fungal community composition was found to differ significantly (p=0.005) between olive tree cultivars, being Nectriaceae the dominant family in cvs. Cobrançosa and Verdeal Transmontana, whereas Pleosporaceae was dominant in the cv. Madural. Epiphytic and endophytic fungal communities also differed in size and in composition in asymptomatic and OK-symptomatic twigs, for the three cultivars. In general, asymptomatic twigs were more diverse and rich (up to 1.4-fold) when compared to OK-symptomatic twigs. Among the species identified in the asymptomatic tissues, Cladosporium cladosporioides and Chromelosporium carneum were the most frequently isolated within epiphytic and endophytic community, respectively; whereas in the OK-symptomatic tissues Cladosporium sp. and Fusarium lateritium were the most frequently isolated within epiphytic and endophytic community, respectively. According to indicator species analysis C. carneum, Pyronema dosmesticum and Phoma aloes (IndVal up to 0.56) may be promising species in the OK suppression. Better acknowledgement should be developed in order to uncover their role on plant health.FEDER funds through COMPETE (Programa Operacional Factores de Competitividade} and by national funds by FCT [Fundação para a Ciência e a Tecnologia) in the framework of the project EXCL/AGR-PRO/0591/2012. T. Gomes thanks FCT, POPH-QREN and FSE for PhD SFRH/BD/98127/2013 Grantinfo:eu-repo/semantics/publishedVersio

Fungal diversity among different annual generations of Prays oleae

Comunicação em painelThe olives and olive oil production are important agricultural activities in Portugal. In the region of Trás-os-Montes, olive orchards are strongly affected by Prays oleae Bern., which is responsible for high losses in the olive production, as much as 40% of the expected yield. This lepidopteran presents three generations per year (phyllophagous, antophagous and carpophagous) that damage the olive tree in different organs (leaves, flowers and fruits, respectively). In an attempt to identify fungi that might cause the death of olive moths, larvae and pupae of those three annual generations were collected and surveyed for natural fungal infection. After their isolation, the fungal agents were molecularly identified by sequencing the amplified internal transcribed spacer (ITS) region of rDNA. In the present work, the diversity of fungal species associated to P. oleae, in several olive orchards located in Trás-os-Montes region, is discussed. The diversity and abundance of fungal species differed between all three generations. Higher diversity was found in the carpophagous generation, followed by the antophagous and phyllophagous generations. The use of already adapted fungal species to control one of the major pests of olive groves will increase the success of a future biocontrol strategy. In this context, the identification of fungi associated to P. oleae from olive orchards provided a pool of potential biocontrol agents. In this work, Beauveria bassiana proved to be the most promising fungus to be used as biocontrol agent against olive moth, being strongly associated to the phyllophagous generation. Other fungal species presenting entomopathogenic, antagonistic and phytopathogenic characteristics were also found.This work has been supported by FCT (PTDC/AGR-AAM/102600/2008)

Barcoding of entomopathogenic fungi from olive tree pests : prospects and limitations

From all the barcoding initiatives in progress, fungal barcode is probably the one where more difficulties have been encountered. While for plants and animais the barcode regions were easy to define, for fungi the choice was not so straightforward. The internal transcribed spacer (ITS) region was one of the proposed DNA regions for barcoding fungi. This is an extensively used region, for molecular systematic and identification of species, being probably the most widely sequenced DNA region of fungi. This is due to the simplicity of the amplification, related to the multicopy nature of the rDNA; the possibility of using universal primers; and the high levei of sequence variation that occurs even between closely related species. Furthermore, a significant number of identified sequences for comparison are available in the GenBank database. Although the ITS region of rDNA was chosen for some groups of fungi, the use of this region presents very limited application for others, especially for Ascomycetes. As some of the most important entomopathogenic fungi are Ascomycetes, belonging to genera Beauveria, Cordyceps, Isaria, Lecanicillium and Paecilomyces, the use of the ITS region for barcoding purpose are being complemented with other regions. This work, based on the identification of fungal entomopathogens isolated directly from cadavers of one of the major pests in olive graves, the olive moth iPrevs oleae Bern.), intends to illustrate the application of the ITS region to identify these fungal species. The use of this region proved to be useful for the identification of most of the entomopathogenic fungi found in dead larvae and pupae of P. oleae. However, the use ot ITS region for barcode purposes did not allow the identification of several isolates, proving the requiremerít of using a second barcoding region, to enable full fungal identification.This work has been supported by FCT (PTDC/AGR-AAM/02600/2008)

Identification of fungi isolated from the olive moth (Prays oleae Bern.) based on ITS region

Fundação para a Ciência e Tecnologia (FCT) - Project PTDC/AGR-AAM/102600/200

Design of glass artifacts through rapid prototyping and rapid tooling

The actual competition environment characterized by fast variations and consumer's sharpnecessity in aesthetic satisfaction demands a constant adaptation of the companies, at thedevelopment and production levels.The production of decorating glass parts by thermoforming, with three-dimensional shapes,demands expensive moulds. The complexity associated to the manufacture of these moulds bytraditional methods represents a substantial aggravation in price and development time of thefinal product, makes their production not attractive.The present work presents adequate methodologies for glass artefacts production bythermoforming, which are based on rapid prototyping models and ceramic moulds hardenedby a sol-gel reaction (indirect rapid tooling process). This technology allows the reduction inthe time to market and opens new opportunities in the design of new and bold artefacts

Importance of the vacuum in rapid tooling of polymeric-based moulds

Metallic powders are typically mixed withepoxy and polyurethane resin systems to improvethe moulds thermal conductivity. The criticalproblem to produce these mixtures for RapidTooling applications is the difficulty of eliminatingthe entrapped air, introduced during theprocessing due to the high viscosity of the mixture,especially in the presence of high aluminiumconcentrations. When air bubbles are retained inthe resin/model interface, superficial defects aregenerated which render inoperative the RapidTooling moulds, and consequently the advantagesof these new technologies.In this work, a specific methodology ispresented to reduce the porosity level, not only inthese typical mixtures, but also in hybrid ones,manufactured with aluminium particles and milledfibres, which have a even worse tendency toproduce pores in the composite interface

Estudo da injecção de termoplásticos em moldes produzidos em compósitos de base epoxídica de alta temperatura

Os moldes rápidos baseados em compósitos de base epoxídica de alta temperatura e utilizados no fabrico rápido de ferramentasapresentam uma durabilidade intermédia entre as chamadas ferramentas soft tooling e hard tooling. Tal facto deve-se àcombinação de uma elevada tenacidade e boa estabilidade térmica das resinas epoxy com a alta rigidez, dureza e boa condutividadetérmica das partículas metálicas. Esta última característica reduz o choque térmico no molde em cada ciclo de moldação, permiteuma redução da temperatura do molde e reduz o tempo do ciclo de injecção.Produziram-se materiais compósitos carregados com elevadas concentrações de partículas de alumínio e materiais compósitoshíbridos constituídos por partículas de alumínio e fibras moídas, que além de serem testados em ensaios de laboratório foramtambém testados em moldes de injecção para termoplásticos. Esta comunicação pretende fornecer os resultados deste estudo quevisa contribuir para a implementação destas tecnologias como alternativa viável para a obtenção de protótipos com tempos e custosreduzidos, permitindo às empresas aumentar a sua competitividade