Piezoelectric composites with high sensitivity and high capacitance for use at high pressures

1991 ◽  
Vol 38 (6) ◽  
pp. 634-639 ◽  
Author(s):  
Q.C. Xu ◽  
S. Yoshikawa ◽  
J.R. Belsick ◽  
R.E. Newnham
Keyword(s):  
High Pressures ◽  
High Sensitivity ◽  
Piezoelectric Composites ◽  
High Capacitance

Porous, Multi-layered Piezoelectric Composites Based on Highly Oriented Pzt/pvdf Electrospinning Fibers for High-performance Piezoelectric Nanogenerators

2021 ◽  
Author(s):  
Xiangxin Du ◽  
Zheng Zhou ◽  
Zhao Zhang ◽  
Liqin Yao ◽  
Qilong Zhang ◽  
...  
Keyword(s):  
Porous Structure ◽  
High Performance ◽  
Mechanical Energy ◽  
High Sensitivity ◽  
Fiber Composites ◽  
Piezoelectric Composites ◽  
Β Phase ◽  
Energy Harvesting Devices ◽  
Piezoelectric Nanogenerators ◽  
Piezoelectric Fiber

Abstract Piezoelectric nanogenerators (PENGs) that can harvest mechanical energy from ambient environment have broad prospects for multi-functional applications. Here, multi-layered piezoelectric composites with a porous structure based on highly oriented PZT/PVDF electrospinning fibers are prepared via a laminating method to construct high-performance PENGs. PZT particles as piezoelectric reinforcing phases are embedded in PVDF fibers and facilitate the formation of polar β phase in PVDF. The multi-layered, porous structure effectively promotes the overall polarization and surface bound charge density, resulting in highly efficient electromechanical conversion. The PENG based on 10 wt.% PZT/PVDF composite fibers with a 220 µm film thickness output an optimal voltage of 62.0 V and a power of 136.9 μW, which is 3.4 and 6.5 times the voltage and power of 10wt.% PZT/PVDF casting film-based PENG, respectively. Importantly, the PENG shows a high sensitivity of 12.4 VN-1, presenting a significant advantage in comparison to PENGs with other porous structures. In addition, the composites show excellent flexibility with a Young’s modulus of 227.2 MPa and an elongation of 262.3%. This work shows great potential application of piezoelectric fiber composites in flexible energy harvesting devices.

scholarly journals Porous, multi-layered piezoelectric composites based on highly oriented PZT/PVDF electrospinning fibers for high-performance piezoelectric nanogenerators

2022 ◽  
Vol 11 (2) ◽  
pp. 331-344
Author(s):  
Xiangxin Du ◽  
Zheng Zhou ◽  
Zhao Zhang ◽  
Liqin Yao ◽  
Qilong Zhang ◽  
...  
Keyword(s):  
Porous Structure ◽  
High Performance ◽  
Mechanical Energy ◽  
High Sensitivity ◽  
Fiber Composites ◽  
Piezoelectric Composites ◽  
Β Phase ◽  
Energy Harvesting Devices ◽  
Piezoelectric Nanogenerators ◽  
Piezoelectric Fiber

AbstractPiezoelectric nanogenerators (PENGs) that can harvest mechanical energy from ambient environment have broad prospects for multi-functional applications. Here, multi-layered piezoelectric composites with a porous structure based on highly oriented Pb(Zr0.52Ti0.48)O3/PVDF (PZT/PVDF) electrospinning fibers are prepared via a laminating method to construct high-performance PENGs. PZT particles as piezoelectric reinforcing phases are embedded in PVDF fibers and facilitate the formation of polar β phase in PVDF. The multi-layered, porous structure effectively promotes the overall polarization and surface bound charge density, resulting in a highly efficient electromechanical conversion. The PENG based on 10 wt% PZT/PVDF composite fibers with a 220 µm film thickness outputs an optimal voltage of 62.0 V and a power of 136.9 µW, which are 3.4 and 6.5 times those of 10 wt% PZT/PVDF casting film-based PENG, respectively. Importantly, the PENG shows a high sensitivity of 12.4 V·N−1, presenting a significant advantage in comparison to PENGs with other porous structures. In addition, the composites show excellent flexibility with a Young’s modulus of 227.2 MPa and an elongation of 262.3%. This study shows a great potential application of piezoelectric fiber composites in flexible energy harvesting devices.

A Study of High-Pressure CO2 Recycling Using Pinewood Char Gasification

2013 ◽  
Author(s):  
Indraneel Sircar ◽  
Anup Sane ◽  
Jay Gore
Keyword(s):  
Experimental Data ◽  
Mass Loss ◽  
Large Scale ◽  
High Pressures ◽  
Fixed Bed ◽  
High Sensitivity ◽  
Reaction Rates ◽  
Fixed Bed Reactor ◽  
Loss Data ◽  
High Pressure Co2

Measurements of the reaction rates at high-pressures for gasification of low-ash pinewood char with CO2 are presented. A fixed-bed reactor operated at 1140–1260 K and 1–10 atm was utilized in the present study. Product gas sampling and gas chromatograph measurements enabled tracking of the gasification progress and mass loss data. The mass loss data are interpreted using the volumetric and non-reactive core models. Activation energy, collision frequency and reaction order are reported for each model. The experimental data show high sensitivity to temperature. The data also show an increase of the apparent gasification rates with higher CO2 pressures. Comparison of computed char conversion profiles and experimental data are discussed in the context of mass transport and effects on the gasification rates. The findings from this study have applications to gasification modeling and design of large-scale gasification systems.

Radio Measurements of Coronal Magnetic Fields

1994 ◽  
Vol 144 ◽  
pp. 21-28 ◽  
Author(s):  
G. B. Gelfreikh
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Solar Corona ◽  
Active Regions ◽  
High Sensitivity ◽  
Coronal Magnetic Field ◽  
Transverse Magnetic ◽  
Radio Sources ◽  
Radio Waves ◽  
Solar Active Regions

AbstractA review of methods of measuring magnetic fields in the solar corona using spectral-polarization observations at microwaves with high spatial resolution is presented. The methods are based on the theory of thermal bremsstrahlung, thermal cyclotron emission, propagation of radio waves in quasi-transverse magnetic field and Faraday rotation of the plane of polarization. The most explicit program of measurements of magnetic fields in the atmosphere of solar active regions has been carried out using radio observations performed on the large reflector radio telescope of the Russian Academy of Sciences — RATAN-600. This proved possible due to good wavelength coverage, multichannel spectrographs observations and high sensitivity to polarization of the instrument. Besides direct measurements of the strength of the magnetic fields in some cases the peculiar parameters of radio sources, such as very steep spectra and high brightness temperatures provide some information on a very complicated local structure of the coronal magnetic field. Of special interest are the results found from combined RATAN-600 and large antennas of aperture synthesis (VLA and WSRT), the latter giving more detailed information on twodimensional structure of radio sources. The bulk of the data obtained allows us to investigate themagnetospheresof the solar active regions as the space in the solar corona where the structures and physical processes are controlled both by the photospheric/underphotospheric currents and surrounding “quiet” corona.

Backscattered Electron Imaging of GaAs/AlGaAs Super Lattice Structures with an Ultra-High- Resolution SEM

1988 ◽  
Vol 46 ◽  
pp. 204-205
Author(s):  
Kazumichi Ogura ◽  
Michael M. Kersker
Keyword(s):  
High Resolution ◽  
Layer Structure ◽  
High Sensitivity ◽  
Beam Current ◽  
Electron Beam Current ◽  
Lattice Structures ◽  
Super Lattice ◽  
Different Types ◽  
Backscattered Electron ◽  
Electron Imaging

Backscattered electron (BE) images of GaAs/AlGaAs super lattice structures were observed with an ultra high resolution (UHR) SEM JSM-890 with an ultra high sensitivity BE detector. Three different types of super lattice structures of GaAs/AlGaAs were examined. Each GaAs/AlGaAs wafer was cleaved by a razor after it was heated for approximately 1 minute and its crosssectional plane was observed.First, a multi-layer structure of GaAs (100nm)/AlGaAs (lOOnm) where A1 content was successively changed from 0.4 to 0.03 was observed. Figures 1 (a) and (b) are BE images taken at an accelerating voltage of 15kV with an electron beam current of 20pA. Figure 1 (c) is a sketch of this multi-layer structure corresponding to the BE images. The various layers are clearly observed. The differences in A1 content between A1 0.35 Ga 0.65 As, A1 0.4 Ga 0.6 As, and A1 0.31 Ga 0.69 As were clearly observed in the contrast of the BE image.

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