Improved long-term electrical stability of pulsed high-power diodes using dense carbon fiber velvet cathodes

2012 ◽  
Vol 19 (7) ◽  
pp. 072119 ◽  
Author(s):  
Jie Yang ◽  
Ting Shu ◽  
Hui Wang
Keyword(s):  
Carbon Fiber ◽  
High Power ◽  
Electrical Stability ◽  
Power Diodes

Effects of high pressure on the crystallization of carbon fiber reinforced polyetheretherketone (CF/PEEK) laminate composites

1990 ◽  
Vol 48 (4) ◽  
pp. 876-877
Author(s):  
Hong-Ming Lin ◽  
C. H. Liu ◽  
R. F. Lee
Keyword(s):  
High Pressure ◽  
Carbon Fiber ◽  
Sample Surface ◽  
High Yield ◽  
Fiber Reinforced ◽  
Laminate Composites ◽  
Peek Composite ◽  
Continuous Carbon Fiber ◽  
Carbon Fiber Reinforced

Polyetheretherketone (PEEK) is a crystallizable thermoplastic used as composite matrix materials in application which requires high yield stress, high toughness, long term high temperature service, and resistance to solvent and radiation. There have been several reports on the crystallization behavior of neat PEEK and of CF/PEEK composite. Other reports discussed the effects of crystallization on the mechanical properties of PEEK and CF/PEEK composites. However, these reports were all concerned with the crystallization or melting processes at or close to atmospheric pressure. Thus, the effects of high pressure on the crystallization of CF/PEEK will be examined in this study.The continuous carbon fiber reinforced PEEK (CF/PEEK) laminate composite with 68 wt.% of fibers was obtained from Imperial Chemical Industry (ICI). For the high pressure experiments, HIP was used to keep these samples under 1000, 1500 or 2000 atm. Then the samples were slowly cooled from 420 °C to 60 °C in the cooling rate about 1 - 2 degree per minute to induce high pressure crystallization. After the high pressure treatment, the samples were scanned in regular DSC to study the crystallinity and the melting temperature. Following the regular polishing, etching, and gold coating of the sample surface, the scanning electron microscope (SEM) was used to image the microstructure of the crystals. Also the samples about 25mmx5mmx3mm were prepared for the 3-point bending tests.

Performance improvement of inverted two-dimensional perovskite solar cells using a non-fullerene acceptor as the trap passivator

2021 ◽  
Author(s):  
Eun-Cheol Lee ◽  
Zhihai Liu
Keyword(s):  
Solar Cells ◽  
Power Conversion Efficiency ◽  
Performance Improvement ◽  
High Power ◽  
Power Conversion ◽  
Perovskite Solar Cells ◽  
Two Dimensional ◽  
High Power Conversion Efficiency ◽  
Long Term Stability

Recently, Ruddlesden–Popper two-dimensional (2D) perovskite solar cells (PSCs) have been intensively studied, owing to their high power conversion efficiency (PCE) and excellent long-term stability. In this work, we improved the...

Hybrid simulation of electrode plasmas in high-power diodes

2009 ◽  
Vol 16 (12) ◽  
pp. 123102 ◽  
Author(s):  
Dale R. Welch ◽  
David V. Rose ◽  
Nichelle Bruner ◽  
Robert E. Clark ◽  
Bryan V. Oliver ◽  
...  
Keyword(s):  
High Power ◽  
Hybrid Simulation ◽  
Power Diodes

Effects of Accelerated Aging Period of Time at 180°C on Tensile Property of Plain Woven Fabric/Epoxy Resin Laminated Composites

2012 ◽  
Vol 182-183 ◽  
pp. 76-79 ◽  
Author(s):  
Lei Lei Song ◽  
Quan Rong Liu ◽  
Jia Lu Li
Keyword(s):  
Tensile Strength ◽  
Carbon Fiber ◽  
Epoxy Resin ◽  
Laminated Composites ◽  
Accelerated Aging ◽  
Woven Fabric ◽  
Accelerated Ageing ◽  
Time Intervals ◽  
Composite Samples

In this paper, carbon fiber reinforced resin matrix composites were produced by stacking eight pieces of carbon fiber woven plain fabric and subjected to accelerated ageing. Accelerated ageing was carried out in oven at 180°C for three different time intervals (60 hours, 120 hours and 180 hours). The influence of different ageing time intervals at 180°C on tensile properties of laminated composites was examined, compared with the composites without aging. The appearance and damage forms of these laminated composites were investigated. The results revealed that the tensile strength of the laminates declined significantly after long term accelerated aging at 180°C. The average tensile strengths of composite samples aged 60 hours, 120 hours, and 180 hours period of time at 180°C are 80.36%, 79.82%, 76.57% of average tensile strength of composite samples without aging, respectively. The high temperature accelerated aging makes the resin macromolecular structure in the composites changed, and then the adhesive force between fiber bundles and resin declines rapidly which result in the tensile strength of composites aged decrease. This research provides a useful reference for long term durability of laminated/epoxy resin composites.

Long-term electrical stability of next generation LV Trench IGBT at Hitachi ABB Power Grids

2021 ◽  
pp. 114300
Author(s):  
Nick Schneider ◽  
Elizabeth Buitrago ◽  
Wolfgang Vitale ◽  
Luca De-Michielis
Keyword(s):  
Power Grids ◽  
Next Generation ◽  
Electrical Stability

Recent Trends in Template Assisted 3D Porous Materials for Electrochemical Supercapacitors

2021 ◽  
Author(s):  
Nilimapriyadarsini Swain ◽  
Saravanakumar Balasubramaniam ◽  
Manab Kundu ◽  
Lukas Schmidt-Mende ◽  
Ananthakumar Ramadoss
Keyword(s):  
Energy Storage ◽  
Porous Materials ◽  
Power Density ◽  
High Power ◽  
High Power Density ◽  
Electrochemical Supercapacitors ◽  
Energy Storage Devices ◽  
Storage Devices ◽  
Recent Trends

Supercapacitors have emerged as an outstanding candidate among numerous energy storage devices because of their long-term cycle life, high power density, and minimal safety concerns. As we know, the lower...

The effect of clogging on the long-term stability of different carbon fiber brushes in microbial fuel cells for brewery wastewater treatment

2020 ◽  
Vol 11 ◽  
pp. 100420 ◽  
Author(s):  
Sarah Brunschweiger ◽  
Emile Tabu Ojong ◽  
Jana Weisser ◽  
Christian Schwaferts ◽  
Martin Elsner ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Fuel Cells ◽  
Carbon Fiber ◽  
Microbial Fuel Cells ◽  
Brewery Wastewater ◽  
Term Stability ◽  
Long Term Stability

scholarly journals Active Stabilization of the Beam Pointing of a High- Power KrF Laser System

2015 ◽  
Vol 22 (1) ◽  
pp. 165-172 ◽  
Author(s):  
A. Barna ◽  
I. B. Földes ◽  
J. Bohus ◽  
S. Szatmári
Keyword(s):  
High Power ◽  
Laser System ◽  
Spot Size ◽  
Electric Signal ◽  
Simple Arrangement ◽  
Krf Laser ◽  
Active Stabilization ◽  
Directional Change ◽  
Position Sensitive Detectors

Abstract An active beam-pointing stabilization system has been developed for a high-power KrF laser system to eliminate the long-term drift of the directional change of the beam in order to have a stable focusing to a high intensity. The control of the beam direction was achieved by a motor-driven mirror activated by an electric signal obtained by monitoring the position of the focus of the output beam. Instead of large sized UV-sensitive position sensitive detectors a simple arrangement with scatter plates and photodiodes are used to measure the directionality of the beam. After the beam stabilization the long-term residual deviation of the laser shots is ~14 μrad, which is comparable to the shot-to-shot variation of the beam (~12 μrad). This deviation is small enough to keep the focal spot size in a micrometer range when tightly focusing the beam using off-axis parabolic mirrors.

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