Local piezoelectric response of single poly(vinylidene fluoride) electrospun fibers

It is shown that electrospun poly(vynilidene fluoride) nanofibers are fully poled right after preparation and show b-phase contents of 70%, therefore being able to be implemented into electroactive devices without further processing steps. Further,the local piezoelectric properties of individual electrospun fibers have been studied by piezoresponse force microscopy. Piezoelectric response, polarization switching, and nanoscale patterning of the fibers have been demonstrated.

Piezoresistive sensors for force mapping of hip-prostheses

The success of artificial prosthetic replacements depends on the fixation of the artificial prosthetic component after being implanted in the thighbone. The materials for fixation are subject to mechanical stresses, which originate permanent deformations, incipient cracks and even fatigue fractures. This work shows the possibility of monitoring the mechanical stress over time in prosthesis. In this way, highly sensitive silicon thin-film piezoresistive sensors were developed attached to prosthesis and their results compared with commercial strain gauge sensors. Mechanical stress-strain experiments were performed in compressive mode, during 10,000 cycles. Experimental data was acquired at mechanical vibration frequencies of 0.5 Hz, 1 Hz and 5 Hz, and sent to a computer by means of a wireless link. The results show that there is a decrease in sensitivity of the thin-film silicon piezoresistive sensors when they are attached to the prosthesis, but this decrease does not compromise its monitoring performance. The sensitivity, compared to that of commercial strain gauges, is much larger due to their higher gauge factors (-23.5), when compared to the GFs of commercial sensors (2).

Injustiça para com a cidade de Barcelos

Começarei com um Princípio Fundamental Constitucional que está (ainda) em vigor: o Direito à Justiça. Art. 20º da Constituição da República Portuguesa: “Acesso ao direito e tutela jurisdicional efectiva”: “1. A todos é assegurado o acesso ao direito e aos tribunais para defesa dos seus direitos e interesses legalmente protegidos, não podendo a justiça ser denegada por insuficiência de meios económicos.”. Abstract: I will begin with a Constitutional Fundamental Principle that is (still) in force: the Right to Justice. Art 20 of the Constitution of the Portuguese Republic. "Access to law and effective judicial protection": "1. Everyone is guaranteed access to the law and the courts to defend their legally protected rights and interests, and justice may not be denied for insufficient economic means. ".

I CONGRESSO JURÍDICO DE INVESTIGADORES LUSÓFONOS: não esqueça a lei!

Quando pessoas com as mais altas responsabilidades institucionais e políticas, em países da lusofonia, alegam “o desconhecimento da lei social e dos impostos”, nada melhor do que ir(em) assistir a um congresso em diversas áreas do Direito para aprenderem um pouco, com entrada gratuita e direito a perguntas e debate. § When people with the highest institutional and political responsibilities in Lusophone countries claim "ignorance of social law and taxation", nothing better than going (in) attend a convention in various areas of law to learn a little, with free admission and the right to question and debate.