Friction stir welding for marine applications : mechanical behaviour and microstructural characteristics of Al-Mg-Si-Cu plates

Friction stir welding is a multipurpose solid-state joining process mainly used for aluminium and steel plates and frames. Friction stir welded non-ferrous metallic alloys, similar or dissimilar, in particular aluminium alloys, provide opportunities for the improvement and developement of new product designs. This paper investigates the correlation between the mechanical behaviour and morphological structures of friction stir welded Al-Mg-Si(Cu) alloy plates in two temper conditions. Micro Vickers hardness and tensile tests were carried out. Additionally, morphology was investigated using optical microscopy and scanning electron microscopy. Samples subjected to the post weld heat treatment were shown to have the best properties owing to the formation of a significant number of hardening particles which, added to the nugget grain refinement, resulted in the increase of the material strength

Friction Stir Welding for Marine Applications: Mechanical Behaviour and Microstructural Characteristics of Al-Mg-Si-Cu Plates

Friction stir welding is a multipurpose solid-state joining process mainly used for aluminium and steel plates and frames. Friction stir welded non-ferrous metallic alloys, similar or dissimilar, in particular aluminium alloys, provide opportunities for the improvement and developement of new product designs. This paper investigates the correlation between the mechanical behaviour and morphological structures of friction stir welded Al-Mg-Si(Cu) alloy plates in two temper conditions. Micro Vickers hardness and tensile tests were carried out. Additionally, morphology was investigated using optical microscopy and scanning electron microscopy. Samples subjected to the post weld heat treatment were shown to have the best properties owing to the formation of a significant number of hardening particles which, added to the nugget grain refinement, resulted in the increase of the material strength

Design de sistemas e processos satisfatórios : uma abordagem transdisciplinar em ambientes acadêmicos e industriais

O objetivo deste artigo é investigar e discutir as considerações gerais sobre o design de sistemas e processos que vão além dos aspectos “técnicos”. Este artigo é um estudo qualitativo resultante da experiência dos autores em ambientes acadêmicos e industriais. É uma experiência combinada de mais de quarenta anos em diferentes profissões, circunstâncias e localizações geográficas (em diferentes continentes). Os resultados sugerem que a velocidade e a complexidade da vida moderna sobrecarregam as pessoas a ponto de se tornarem dependentes de sistemas e processos desnecessários. Os sistemas devem ser projetados com um nível de flexibilidade para permitir que os processos sejam dinâmicos e se adaptem com o tempo. Isto é conseguido através de um processo de aprendizagem focado em informações relevantes em bem embasadas combinado a uma abordagem transdisciplinar.The aim of this paper is to inquire and discuss the overall considerations concerning the design of systems and processes beyond the “technical” aspects. This article is a qualitative study resulting from the experience of the authors in both academic and industrial environments. It is a combined experience of over forty years in different professions, circumstances, and geographical locations (spanning continents). Results suggest that the speed and complexity of modern life overwhelms people to the point that they become dependent on redundant systems and processes. Systems should be designed with a level of flexibility to allow processes to be dynamic and to adapt with time. This is achieved through a focused learning process based on strong and relevant information combined with a transdisciplinary approach

Técnica de criação massal de Diabrotica speciosa (Gemar, 1824) (Coleoptera: Chrysomelidae)

Diabrotica speciosa is a pest of great agricultural importance in Brazil. It causes damage in many cultures from the larval stage to adulthood, being a polyphagous plague. During larva stage, it causes damage to the roots, while in adulthood; it causes damage to the aerial parts of the plant. The objective was to improve the mass rearing technique of D. speciosa in the laboratory in order to provide material for bioassay management of this insect pest. Adults of D. speciosa were collected in the field and placed in cages into camera type B.O.D. The eggs were deposited in lined Petri plates. When the eggs hatched, the larvae were transferred to a container containing vermiculite and fed with seminal roots of popcorn, for the insects fulfilled their immature cycle. The results showed that median days for egg phases development (beginning of laying to hatching) was 9 days and larvae to pupae period (until the emergence) was 26 days. The viability represented by the ratio of eggs to the number of emerged adults was only 22.58%. Thus, the mass rearing method tested was not viable for mass production of D. speciosa.A Diabrotica speciosa é uma praga de grande importância agrícola no Brasil, pois causa danos em várias culturas desde a fase de larva até a fase adulta, por ser uma praga polífaga. Durante a fase de larva do inseto, causa danos nas raízes, enquanto na fase adulta, ele causa danos na parte aérea da planta. O objetivo do trabalho foi aperfeiçoar a técnica de criação massal de D. speciosa em laboratório com o objetivo de fornecer material para bioensaios de manejo deste inseto-praga. Adultos de D. speciosa foram coletados a campo e colocados em gaiolas dentro de câmara do tipo B.O.D. Os ovos foram depositados em placas de Petri forradas. Quando os ovos eclodiram, as larvas foram transferidas para um recipiente contendo vermiculita e alimentadas com raízes seminais de milho pipoca, para que os insetos completassem seu ciclo imaturo. Os resultados demonstraram que o período médio de dias para o desenvolvimento das fases ovo (início da postura até a eclosão) foi de 9 dias e o período larva a pupa (até a emergência) foi de 26 dias. A viabilidade representada pela relação de ovos com o número de insetos adultos emergidos foi apenas 22,58%. Portanto, o método de criação massal testado não foi viável para a produção massal de D. speciosa

3D scanning of Porto Alegre Museum Artifacts : the crockery of the Rocco Bakery

3D Scanning of Porto Alegre Museum Artifacts: The Crockery of the Rocco Bakery Antiques usually require careful handling, so these objects cannot be made available to the general public and are handled only by restoration specialists. This article focuses on the preservation of antiquities in terms of cultural heritage and the availability of these objects for access by visitors, it describes and evaluates the development of a method to support the digitisation of objects considered solids of revolution. The artifacts were provided by the Museu Joaquim José Felizardo in the city of Porto Alegre, Brazil, and were used to set the table in the former Confeitaria Rocco (bakery). The 3D process consisted of the following steps: laser scanning, data processing of the coordinates obtained from the surface of the object into point clouds, creation of the virtual model, creation of a physical model using additive manufacturing, and evaluation of the physical model in comparison with the original artifact. The obtained results show that highly accurate models can be created using the proposed method. Therefore, virtual data can be obtained for the conservation, restoration and creation of replicas for studies and accessibility