Poly[R-3-hydroxybutyrate-co-(R-3-hydroxyvalerate)] (PHBVs) copolymers are promising biopolymers, which could substitute petroleum-based plastics for various applications. PHB and PHBV pellets were processed on a custo...Poly[R-3-hydroxybutyrate-co-(R-3-hydroxyvalerate)] (PHBVs) copolymers are promising biopolymers, which could substitute petroleum-based plastics for various applications. PHB and PHBV pellets were processed on a customized 3D printer via Fused Granular Manufacturing (FGM) approach modified with a Mahor screw extruder. To anticipate the behaviour of PHBVs when transformed using conventional thermo-mechanical shaping processes, thermal and mechanical analyses were carried out in order to better understand the effect of annealing temperature on their crystallization behaviour and mechanical properties of PHB polymer and PHBV copolymer. The objectives of the present work were to propose an experimental strategy to study the melting and crystallization events, crystalline structure changes, and mechanical performances of both PHB homopolymer and PHBV copolymer according to identical thermal annealing treatments. A monitoring of 3D printed PHB and PHBV structures was achieved by coupling Differential Scanning Calorimetry (DSC) and tensile tests. .展开更多
The variation in temperature on the island of Gran Canaria is studied using the method applied to the nearby island of Tenerife [1]. An upward warming trend of 0.09°C ± 0.05°C (α = 0.01) was seen from ...The variation in temperature on the island of Gran Canaria is studied using the method applied to the nearby island of Tenerife [1]. An upward warming trend of 0.09°C ± 0.05°C (α = 0.01) was seen from 1946 to date, which has accelerated since the seventies to 0.17°C ± 0.10°C (α = 0.01). The increase was higher at night (0.11°C ± 0.05°C) than by day (0.08°C ± 0.06°C), so the temperature range decreased slightly. These values are similar to those of Tenerife and the time series of anomalies for the two islands are highly correlated. On the coast the same relationship to the sea surface temperature was found as in Tenerife, but in the mid-altitude areas to windward, some differences were detected that are hypothetically attributable to the different relief of the two islands.展开更多
文摘Poly[R-3-hydroxybutyrate-co-(R-3-hydroxyvalerate)] (PHBVs) copolymers are promising biopolymers, which could substitute petroleum-based plastics for various applications. PHB and PHBV pellets were processed on a customized 3D printer via Fused Granular Manufacturing (FGM) approach modified with a Mahor screw extruder. To anticipate the behaviour of PHBVs when transformed using conventional thermo-mechanical shaping processes, thermal and mechanical analyses were carried out in order to better understand the effect of annealing temperature on their crystallization behaviour and mechanical properties of PHB polymer and PHBV copolymer. The objectives of the present work were to propose an experimental strategy to study the melting and crystallization events, crystalline structure changes, and mechanical performances of both PHB homopolymer and PHBV copolymer according to identical thermal annealing treatments. A monitoring of 3D printed PHB and PHBV structures was achieved by coupling Differential Scanning Calorimetry (DSC) and tensile tests. .
文摘The variation in temperature on the island of Gran Canaria is studied using the method applied to the nearby island of Tenerife [1]. An upward warming trend of 0.09°C ± 0.05°C (α = 0.01) was seen from 1946 to date, which has accelerated since the seventies to 0.17°C ± 0.10°C (α = 0.01). The increase was higher at night (0.11°C ± 0.05°C) than by day (0.08°C ± 0.06°C), so the temperature range decreased slightly. These values are similar to those of Tenerife and the time series of anomalies for the two islands are highly correlated. On the coast the same relationship to the sea surface temperature was found as in Tenerife, but in the mid-altitude areas to windward, some differences were detected that are hypothetically attributable to the different relief of the two islands.
