33 documents found, page 1 of 4
Design and industrial implementation of a multi-functional part produced by pow...
Lopes, A. C.; Sampaio, Álvaro M.; Fernandes, F.; Vaz, P. M.; Pontes, A. J.The use of robot end-effectors programmed to perform handling tasks in industrial environments has expanded in several sectors as a consequence of the rapid digital transformation seen in recent years. With such growing demands, additive manufacturing is evolving in the robotics field with more efficient, innovative, and customer-specific solutions owing to its design flexibility. Thus, this work presents a rob...
The double cantilever beam test applied to mode I fracture characterization of ...
Lopes, A. C.; Silva, E. C.; Dourado, N.; de Moura, M. F.S.F.; Sampaio, Álvaro M.; Pontes, A. J.In recent years, parts produced by Selective Laser Sintering (SLS) technology have aroused growing interest due to their valuable potential for end-use applications. However, to ensure the applicability of SLS products for advanced structural purposes, an accurate characterization of their mechanical behaviour is essential, which includes the assessment of fracture performance. Thus, cohesive zone modelling tha...
The influence of the energy density on dimensional, geometric, mechanical and m...
Lopes, A. C.; Sampaio, Álvaro M.; Pontes, A. J.Selective Laser Sintering (SLS) is a Powder Bed Fusion technology that embraces a large number of variables influencing the properties of the parts produced. The well-known dependence and complex interaction established between the main process parameters demands continuous empirical research for effective SLS monitoring. The assessment of the energy density supplied by the laser beam to the powder bed during t...
Composite materials with MWCNT processed by Selective Laser Sintering for elect...
Lopes, A. C.; Sampaio, Álvaro M.; Pontes, A. J.Selective Laser Sintering (SLS) is an additive manufacturing technology that enables the production of polymeric parts for end-use applications. Despite the great potential of conventional materials, carbon-based reinforcements have been widely considered to contradict the electrically insulating nature of polymers, allowing the applicability of SLS in novel applications within electronics industry. However, th...
Wavelet compression and transmission of deformable surfaces over networks
Lopes, A. C.; Gamito, M.; Dias, J. M. S.An animation of a deformable surface with fixed topology is formed by a set of connected points (particles), which follow a trajectory over time. The transmission of such an animation is a task that consumes large amounts of bandwidth, as the position of each particle, in each time instant, needs to be transmitted. We propose a wavelet-based compression and streaming mechanism that allows the minimization of th...
Sistema de orientação para o interior de edifícios: Solução visual de localização
Marcos, J. S.; Dias, J. M. S.; Lopes, A. C.Neste artigo apresentamos um sistema para computação móvel em cenários interiores, baseado em PDA, que consegue resolver com técnicas de visão por computador, a localização do utilizador e possibilita a sua orientação dentro de um edifício através de marcas dispostas em locais estratégicos, previamente identificados. As marcas, capturadas com a câmara de vídeo integrada no PDA, são conhecidas pelo sistema, que ...
A aromaterapia como intervenção de enfermagem na pessoa com ansiedade: uma revi...
Arsénio, C.; Moreira, M.; Lopes, A. C.; Santos, L.; Rocha, M.; Graça, M. Pérez; Silva, I.; Teca, A.; Marques-Vieira, C. M. A.
Novel hybrid multifunctional magnetoelectric porous composite films
Martins, Pedro Libânio Abreu; Lanceros-Méndez, S.; Goncalves, R.; Lopes, A. C.; Venkata Ramana, E.; Mendiratta, S. K.Novel multifunctional porous films have been developed by the integration of magnetic CoFe2O4 (CFO) nanoparticles into poly(vinylidene fluoride)-Trifuoroethylene (P(VDF-TrFE)), taking advantage of the synergies of the magnetostrictive filler and the piezoelectric polymer. The porous films show a piezoelectric response with an effective d33 coefficient of -22 pC/N-1, a maximum magnetization of 12 emu.g-1 and a m...
Poly(vinylidene fluoride-trifluoroethylene)/NAY zeolite hybrid membranes as a d...
Salazar, H.; Lima, A. C.; Lopes, A. C.; Botelho, Gabriela; Lanceros-Méndez, S.Poly(vinylidene fluoride-trifluoroethylene)/NaY zeolite composite membranes were prepared by solvent casting and evaluated as a suitable drug release platform through the evaluation of loading and release of ibuprofen. The membranes were characterized at the morphological, structural and mechanical levels. The 1H-NMR spectra indicate that only the membranes with 16 and 32 % of NaY were useful for IBU encapsulat...
Dielectric relaxation dynamics of high-temperature piezoelectric polyimide copo...
Maceiras, A.; Costa, C. M.; Lopes, A. C.; San Sebastián, M.; Laza, J. M.; Vilas, J. L.; Ribelles, J. L. G.; Sabater i Serra, R.; Andrio Balado, A.Polyimide co-polymers have been prepared based on different diamines as co-monomers: a diamine without CN groups and a novel synthesized diamine with two CN groups prepared by polycondensation reaction followed by thermal cyclodehydration. Dielectric spectroscopy measurements were performed and the dielectric complex function, ac conductivity and electric modulus of the co-polymers were investigated as a functi...