21 documents found, page 1 of 3
Protective coatings for complex organic flexible materials I: characterization ...
Tiss, Belgacem; Martínez-Martínez, D.; Mansilla, C.; Gomes, J. R.; Abreu, C. S.; Pereira, N.; Cunha, L.The escalating imperative to combat the climate change has generated sustainability trends, leading to a rising demands for eco-friendly products. Cork and rubber are versatile materials based or derived from natural sources with various industrial uses and applications. This work represents the first part of a comprehensive investigation focusing on cork, with rubber being the subject of a subsequent paper. Co...
Deep neural network potential model (DNNP) for predicting the friction and wear...
Abreu, C. S.; Gomes, J. R.Accelerating the discovery of materials with desired properties has been a long-standing challenge in materials sciences. Nonetheless, the computational cost of accurate quantum-mechanical calculations proves prohibitive for simulations involving larger spatial and time scales. In recent years, increased efforts to overcome this bottleneck have been undertaken using machine learning (ML), where only a reduced s...
Molecular dynamics comparative study of the friction performance of sustained u...
Abreu, C. S.; Gomes. J. R.A comparative study of the friction performance of multiwalled carbon and boron nitride nanotubes acting as nanobearings was done using molecular dynamics simulations. Boundary conditions corresponding to a steady isothermal simulation were imposed to the nanobearings in order to assess the magnitude of the friction torque and friction forces present, when subjected to rotational frequencies in the range 25-250...
Dynamic aspects of oral processing of curcumin-loaded solid lipid nanoparticles...
Gonçalves, Raquel Filipa Silva; Abreu, C. S.; Gomes, J. R.; Vicente, A. A.; Pinheiro, A. C.; Vieira J. M.Mouthfeel and consistency originating from the consumption of yoghurts represent decisive factors for the consumers’ acceptability. The present work aims to identify potential differences in the sensory perceptions of yoghurts with curcumin-loaded solid lipid nanoparticles (SLN) incorporation. Thus, rheology coupled with tribology were considered to simulate the dynamic aspects of oral processing. Similar value...
Implant surface design for improved implant stability - a study on Ti6Al4V dens...
Bartolomeu, Flávio; Costa, M. M.; Gomes, J. R.; Alves, N.; Abreu, C. S.; Silva, Filipe Samuel; Miranda, Maria Georgina MacedoFocusing on implant surface design, aiming to improve implant primary stability, SLM technology was explored to produce dense and cellular structured Ti6Al4V specimens. The SLM specimens and also a commercial casted/forged Ti6Al4V group, were sandblasted and acid-etched to obtain a moderate surface roughness topography, typically used in implant manufacturing. Ti6Al4V-bone interaction and tribological performan...
Ti6Al4V laser surface preparation and functionalization using hydroxyapatite fo...
Faria, D.; Abreu, C. S.; Buciumeanu, Mihaela; Dourado, N.; Carvalho, Óscar Samuel Novais; Silva, F. S.; Miranda, G.This work presents a novel texture design for implants surface functionalization, through the creation of line-shaped textures on Ti6Al4V surfaces and subsequent sintering of hydroxyapatite (HAp) powder into the designated locations. HAp-rich locations were designed to avoid HAp detachment during insertion, thus guaranteeing an effective osseointegration. This process starts by creating textured lines using a N...
Effect of HAp and beta-TCP incorporation on the tribological response of Ti6Al4...
Dantas, T. A.; Costa, M. M.; Miranda, Maria Georgina Macedo; Silva, Filipe Samuel; Abreu, C. S.; Gomes, J. R.Titanium and its alloys have been widely used in many engineering areas due to their properties. Despite having a high implant-tissue osseointegration time, Ti6Al4V has been extensively used in prosthesis and articular implants. To promote a faster bone ingrowth and consequently reduce the implant fixation time, the addition of a bioactive phase to form a biocomposite seems to be an excellent solution. Because ...
Effect of relative humidity and temperature on the tribology of multilayer micr...
Shabani, M.; Abreu, C. S.; Gomes, J. R.; Silva, R. F.; Oliveira, F. J.The tribological behavior of tenfold micro/nanocrystalline CVD diamond multilayers is here investigated in self–mated configuration using ball-on-plate reciprocating wear testing. The effects of relative humidity (RH) and temperature (T) on friction and wear coefficients are assessed. The strongest effect of humidity was found on the value of the critical load (no delamination) that triples from 40 N at 10%RH t...
Bioactive materials driven primary stability on titanium biocomposites
Dantas, T. A.; Abreu, C. S.; Costa, M. M.; Miranda, G.; Silva, F. S.; Dourado, N.; Gomes, J. R.The Ti6Al4V alloy constitutes an alternative choice to the most common metal-polymer solutions for total hip arthroplasty (THA) due to good biocompatibility, optimal mechanical properties and high load bearing capacity. However, as Ti6Al4V is not bioactive in its conventional form, hydroxyapatite (HAp) and tricalcium phosphate (TCP) have been widely used as coatings of metal prostheses due to their osteogenic p...
Tribological characterization of TiO2/Au decorative thin films obtained by PVD ...
Abreu, C. S.; Matos, José C.; Cavaleiro, A.; Alves, E.; Barradas, N. P.; Vaz, F.; Faro, Marc Torrell; Gomes, J. R.The aim of this work is to evaluate the tribological behavior of decorative thin film nanocomposites consisting of gold nanoparticles dispersed in a dielectric matrix of TiO2. The main focus is given to the changes in the friction coefficient and wear rate, as well as on the overall tribological features resulting from the morphological changes induced by annealing experiments in vacuum, at increasing temperatu...