16 documents found, page 1 of 2
Effect of Carbon Nanofibers on the Viscoelastic Response of Epoxy Resins
Santos, Paulo; Silva, Abílio P.; Reis, Paulo N. B.Two epoxy resins with different viscosities were enhanced up to 1 wt.%, applying a simple method with carbon nanofibers (CNFs). These were characterized in terms of static bending stress, stress relaxation, and creep tests. In bending, the contents of 0.5 wt.% and 0.75 wt.% of CNFs on Ebalta and Sicomin epoxies, respectively, promote higher relative bending stress (above 11.5% for both) and elastic modulus (13....
Compressive Behaviour of 3D-Printed PETG Composites
Valvez, Sara; Silva, Abílio P.; Reis, Paulo N. B.It is known that 3D-printed PETG composites reinforced with carbon or Kevlar fibres are materials that can be suitable for specific applications in the aeronautical and/or automotive sector. However, for this purpose, it is necessary to understand their mechanical behaviour, which is not yet fully understood in terms of compression. Therefore, this study intends to increase the knowledge in this domain, especia...
Tricalcium phosphate doped with Mg2+ and combinations of Mn2+, Zn2+ and Fe3+: A...
Macedo, Duarte F.; Cunha, Ana F.; Mano, João F.; Oliveira, Mariana B.; Silva, Abílio P.Bioactive ceramics such as tricalcium phosphate (TCP) doped with metal ions are often used to replace natural bone in orthopedic and dental function, both in structural and coating applications. Although the addition of different ions to TCP has been correlated with improved mechanical performance, as well as pro-osteogenic and osteointegrative biological activities, the effect of combining different ions in si...
Young’s modulus and hardness of multiphase CaZrO3 -MgO ceramics by micro and na...
Silva, Abílio P.; Booth, Fernando; Garrido, Liliana; Aglietti, Esteban; Pena, Pilar; Baudin, CarmenThe aim of this work is to determine the values of the hardness and elastic modulus of the phases present in CaZrO3-MgO-ZrO2 composites and to analyse their contribution to the composite properties. Two materials previously developed with the same major phases (CaZrO3, MgO and c-ZrO2) present in different volume fractions and grain size have been analysed. The hardness and Young´s modulus of each phase determin...
Castable systems designed with powders reclaimed from dismantled steel inductio...
Silva, Abílio P.; Segadães, A M; Lopes, Rogério A.Despite environmental pressures and intrinsic recycling potential, spent refractories waste is generally considered an economically unattractive waste stream. This work proposes an upgraded view of the debris recovered from dismantled spinel-bonded high-alumina linings of steel induction furnaces, demonstrating that it can be reused in the form of vibratable and self-flowing castable systems. The recovered mate...
Characterization of the Mechanical and Biological Properties of a New Alumina S...
Batista, Patrícia Sofia Pinhanços; Rodrigues, Miguel; Silva, Daniela; Morgado, Patrícia I.; Henriques, J.; Almeida, Maria; Silva, Abílio P.Purpose: In this work, an alumina scaffold was produced through a new method to be used in a near future as a bone substitute. Methods: In vitro and in vivo studies were performed in order to characterize the mechanical and biological properties of the scaffold. Results: the results obtained showed that this scaffold has high mechanical resistance and a porous surface that allows human osteoblast cells to adher...
Reciclagem de agregados das minas da Panasqueira como revestimento refratário d...
Herrera, J. Montoya; Suarez, J.A. Durán; Silva, Abílio P.; Cano, R. Peralbo; Gomes, João CastroNas minas da Panasqueira (Covilhã, Portugal) acumulam-se montes de resíduos (agregados) provenientes da extração de tungsténio sem qualquer aplicação. Este trabalho pretende contribuir para implementar um novo uso para estes resíduos integrando-os como revestimento refratário no processo de moldação a verde da fundição de metais não ferrosos. Os resultados mostram o potencial do uso destes resíduos da fundição ...
Bioactive polymeric–ceramic hybrid 3D scaffold for application in bone tissue r...
Torres, Ana; Gaspar, V. M.; Serra, Inês Raquel Tavares; Carlos, Gabriela Soares Diogo; Fradique, Ricardo Gil; Silva, Abílio P.; Correia, I.J.The regeneration of large bone defects remains a challenging scenario from a therapeutic point of view. In fact, the currently available bone substitutes are often limited by poor tissue integration and severe host inflammatory responses, which eventually lead to surgical removal. In an attempt to address these issues, herein we evaluated the importance of alginate incorporation in the production of improved an...
Hygrothermal Effect on the Impact Response of Carbon Composites with Epoxy Resi...
Reis, Paulo Nobre Balbis dos; Silva, Abílio P.; Santos, P.; Ferreira, J. A. M.This paper presents the results of the hygrothermal effect on the impact response of carbon/epoxy composites and the benefits gained from doping the epoxy resin with nanoclays previously subjected to a silane treatment appropriate for the resin. The nanoclay reinforcement increased the maximum load and the elastic recovery of the composites. The thermal degradation caused by exposure to 60°C for 10 days was ins...
Thermomechanical evaluation of self-flowing refractory castables with and witho...
Pinto, Deesy G.; Silva, Abílio P.; Segadães, A M; Devezas, TessalenoMuch has been discussed about the advantages regarding the thermomechanical performance of self-flow refractory castables (SFRC), with very little or no addition of calcium aluminate cement (CAC) when compared to conventional composites with cement. Previous works demonstrated that a 100% alumina SFRC with optimized particle size distribution simultaneously results in high-flowability fresh paste and high mecha...