1,721,405 research outputs found
Natural fibres and their composites
Full text linkDue to several promising properties, such as their low density and specific properties, low price, easy processing, health advantages, renewability and recyclability, increasing attention was paid in the last years to natural fibres as alternatives to synthetic counterparts for the reinforcement of polymeric based composites [...]
Analisi dei regimi di circolazione dei flussi d'aria all'interno dell'unità ambientale attraverso la valutazione dell'elemento tecnico infisso
No full textIl piano di manutenzione informatizzato. Metodologie e criteri per la gestione informatizzata del processo manutentivo.
No full text(a cura di
Il piano di manutenzione informatizzato. Metodologie e criteri per la gestione informatizzata del processo manutentivo.
No full text(a cura di
A simplified predictive approach to assess the mechanical behavior of pinned hybrid composites aged in salt-fog environment
Full text linkAim of this paper is to assess the predictive capabilities of a simplified theoretical approach on the failure load of aged pinned hybrid composites. In particular, the mechanical performances of glass-flax hybrid epoxy laminates exposed to salt spray fog environment, were used as input data in order to address the analytical model. Preliminarily, the relationship among mechanical performances, failure mechanisms, joint geometry and ageing time, was evaluated by double-lap joint tests on pinned samples at varying joint geometry and ageing time. The bearing and shear out limit stress of samples aged for 60 days under the salt-fog environment underwent a reduction of about 20% compared to the unaged one. Instead, the net-tension limit stress evidenced a reduction slightly above 10%. Afterward, a simplified theoretical approach, based on failure mechanisms stress limits, was proposed to forecast both joint resistance and failure mechanism occurrence. The composite degradation in a salt-fog spray environment was also taken into account in the model. The results highlight a good reliability, with an average error of about 6–8% compared to experimenatal results, thus indicating the suitability of the proposed approach to support the long-term design of a specific pinned composite subject to critical aggressive environments
Il controllo del sistema verde/ costruito per il parco urbano ottocentesco: strumenti di supporto al processo di decisionale per il progetto di recupero
No full textI temi dell'intervento dull'esistente e della riqualificazione degli spazi urbani sollecitano un ripensamento critico sulle tematiche della conservazione e del recupero degli spazi a verde. Su questa premessa la tesi elabora un criterio di lettura del sistema verde/ costruito che indaga, nell'ambito dello specifico disciplinare della Tecnoligia dell'Architettura, la qualità delle informazioni necessarie alla progettazione degli interventi di recupero dei parchi storici
A systematic literature review on less common natural fibres and their biocomposites
No full textInterest in utilization of renewable resources is increasing because of public's environmental awareness and economic considerations. Lignocellulosic fibres have already attracted growing attention as reinforcement of polymeric matrices instead of synthetic ones (mainly glass) from the academic and industrial fields. In addition to kenaf, hemp, sisal, flax and jute, which are the subject of extensive investigations for composite applications since the 1970s, in the last years several researchers suggested the use of less common natural fibres, due to their low cost and availability. This paper reviews the extraction methods, chemical, morphological, thermal and mechanical properties of these less exploited natural fibres reported in literature, discussing their advantages and challenges through comparison against various traditional plant fibres. The introduction of these less common natural fibres in thermoplastic and thermosetting matrices is critically discussed and compared with several standard biocomposites. These renewable and less investigated plant fibres can also be regarded as a source of nanocellulose aimed to enhance the green character of the final composites, thus pushing the industry to move towards such environmentally friendly materials
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