Encontrados 102 documentos, a visualizar página 1 de 11

Piezoelectric co-axial filaments produced by co-extrusion of poly(vinylidene fl...

Documento submetido para revisão pelos pares. A publicar em "Journal of applied polymer science". ISSN 1097-4628. Article first published online: 3 APR 2014 : http://onlinelibrary.wiley.com/doi/10.1002/app.40710/abstract. DOI 10.1002/app.40710. ; The development of new thermoplastic polymer-based piezoelectric sensors with filament geometry is described. These filaments are appropriate for integration into tex...

Processing and electrical response of fully polymer piezoelectric filaments for...

This paper describes the production and characterization of novel geometries for piezoelectric products with a large potential in the design and implementation of flexible sensors produced at low cost and high rates. In particular, the filament geometry, appropriate for integration into textiles, is analyzed. Piezoelectric filaments producing electrical signals under bending or traction stress, thus acting as m...

Caso clinico: Apresentação rara e de difícil diagnóstico de um Linfoma Plasmoci...

Os linfomas de baixo grau plasmocitóides caracterizam-se por adenopatias periféricas, comprometimento do baço e invasão medular nos diversos estádios da doença. Os autores apresentam o caso clinico de um doente com 63 anos de idade, antecedentes pessoais de vitiligo, admitido por anorexia, astenia e perda ponderal de 30Kgs, associado a bicitopénia grave (Hb 6.4mg/dL, normocítica, normocrómica, e leucopenia de ...

Distribution of 3G signals over fiber

In this work we study the feasibility of UMTS (3G) transmission over Passive Optical Networks (P.O.N.). In order to achieve such objective, it was developed a simulator, so that we could correctly model the system and conclude about its impairments. The simulation results obtained validate this kind of transmission and highlight the associated limitations. ; Neste trabalho é estudada a viabilidade da tr...

Study of hepatocellular function in the murine model following hepatic artery s...

PURPOSE: To investigate the impact of selective hepatic artery clamping (SHAC) in hepatocellular function. METHODS: Three groups of Wistar male rats were subjected to SHAC ischemia period of 60min: Group A continuous SHAC were subjected to SHAC ischemia period of 60min, Group B intermittent SHAC of 30min with 5min of reperfusion and Group C intermittent SHAC of 15min with 5min of reperfusion. Animals without SH...

Three layer polymer piezoelectric filaments produced by extrusion

Poly(vinylidene fluoride) (PVDF) is extensively studied due to its piezo-, pyro- and ferroelectric properties. These properties enable the use of this polymer in a number of applications either as sensor or actuator. PVDF is a semi-crystalline polymer and can crystallize in four different crystalline phases, called α, β, γ and δ. The β-phase presents the most interesting electroactive activity. These properties...

Properties and processing by extrusion of electrically conductive multilayer fi...

This work describes the production and characterization of three-layer piezoelectric filaments using two different electrically conductive polymers. The filaments were produced in a filament extrusion line, equipped with a coextrusion die that enabled a coaxial arrangement for a three-layer filament. For the inner and outer layers two different electrically conductive compounds were used, and the middle layer w...

Coextrusion of multilayer piezoelectric tape

Materials with piezoelectric properties are defined as materials that produce an electrical potential when subjected to mechanical stress (sensor function) or, in the opposite sense, produce mechanical work when subjected to an electrical field (actuator function). Poly(vinylidene fluoride), PVDF, is a polymer with a high piezoelectric coefficient, and thus is often used in the above mentioned applications. Th...

Extrusion of poly(vinylidene fluoride) recycled filaments : effect of the proce...

This study analyses the possibility of reprocessing used poly(vinylidene fluoride), PVDF, maintaining the main properties critical for its use in piezoelectric sensor/actuator applications. The influence of multiple reprocessing cycles of PVDF on crystallinity and ß-phase content fundamental for its electroactive behaviour, was studied. Nine reprocessing cycles were completed and it was found that the material ...

Pheno-metabolomics characterization of a Saccharomyces cerevisiae strain collec...