scholarly journals Achieving ultrahigh instantaneous power density of 10 MW/m2 by leveraging the opposite-charge-enhanced transistor-like triboelectric nanogenerator (OCT-TENG)

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hao Wu ◽  
Steven Wang ◽  
Zuankai Wang ◽  
Yunlong Zi
Keyword(s):  
Power Density ◽  
High Power ◽  
Power Output ◽  
Mechanical Energy ◽  
Open Circuit ◽  
Triboelectric Nanogenerator ◽  
Enhancement Effect ◽  
Opposite Charge ◽  
Instantaneous Power ◽  
High Power Output

AbstractConverting various types of ambient mechanical energy into electricity, triboelectric nanogenerator (TENG) has attracted worldwide attention. Despite its ability to reach high open-circuit voltage up to thousands of volts, the power output of TENG is usually meager due to the high output impedance and low charge transfer. Here, leveraging the opposite-charge-enhancement effect and the transistor-like device design, we circumvent these limitations and develop a TENG that is capable of delivering instantaneous power density over 10 MW/m2 at a low frequency of ~ 1 Hz, far beyond that of the previous reports. With such high-power output, 180 W commercial lamps can be lighted by a TENG device. A vehicle bulb containing LEDs rated 30 W is also wirelessly powered and able to illuminate objects further than 0.9 meters away. Our results not only set a record of the high-power output of TENG but also pave the avenues for using TENG to power the broad practical electrical appliances.

Riders use their centre of mass to amplify crank power during non-seated cycling

2019 ◽  
Author(s):  
Ross D. Wilkinson ◽  
Andrew G. Cresswell ◽  
Glen A. Lichtwark
Keyword(s):  
High Power ◽  
Power Output ◽  
Mechanical Energy ◽  
Peak Amplitude ◽  
Centre Of Mass ◽  
Movement Strategies ◽  
High Power Output ◽  
Total Mechanical Energy ◽  
Seated Posture ◽  
Power Outputs

When cyclists ride off the saddle during climbing and sprinting, their centre of mass (CoM) appears to go through a rhythmic vertical oscillation during each crank cycle. Just like in walking and running, the pattern of CoM movement may have a significant impact on the mechanical power that needs to be generated and dissipated by muscle. To date, neither the CoM movement strategies during non-seated cycling, nor the limb mechanics that allow this phenomenon to occur, have been quantified. Here we estimate how much power can be contributed by a rider’s CoM at each instant during the crank cycle by combining a kinematic and kinetic approach to measure CoM movement and joint powers of fifteen participants riding in a non-seated posture at three individualised power outputs (10%, 30%, and 50% of peak maximal power) and two different cadences (70 rpm and 120 rpm). Our analysis confirmed that vertical oscillations of the CoM occur within each crank cycle, with a peak-to-peak amplitude that increases significantly with power output and with decreasing cadence. Accordingly, the greatest peak-to-peak amplitude of CoM displacement (0.06 ± 0.01 m) and change in total mechanical energy (0.54 ± 0.12 J·kg-1) occurred under the combination of high power output and low cadence. Additionally, at the same combination of high power output and low cadence, we found that the peak rate of CoM energy loss (3.87 ± 0.93 W·kg-1) was equal to 18% of the peak crank power, which coincided with a near horizontal crank position (107 ± 10°). As a consequence, it appears that for a given power output, changes in CoM energy contribute to peak instantaneous power output at the crank, thus reducing the required muscular contribution. These findings suggest that riders can use the inertia of their CoM as a mechanical amplifier during non-seated cycling, which has important implications for both rider and bicycle performance.

Design of a novel photoelectrochemical enzymatic biofuel cell with high power output under visible light

2021 ◽  
pp. 134037
Author(s):  
Xinzhou Huang ◽  
Long Ren ◽  
Chunyun Jiang ◽  
Xiangxiang Han ◽  
Xiaoshuang Yin ◽  
...  
Keyword(s):  
Visible Light ◽  
High Power ◽  
Power Output ◽  
Biofuel Cell ◽  
Enzymatic Biofuel Cell ◽  
High Power Output

Thermal Analysis and Experiment of a Ka-Band High-Power Output Window

2021 ◽  
Author(s):  
Quanhong Lu ◽  
Jianxun Wang ◽  
Xinjie Li ◽  
Yixin Wan ◽  
Wei Jiang ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
High Power ◽  
Power Output ◽  
Output Window ◽  
Ka Band ◽  
High Power Output

scholarly journals Abnormally High Power Output of Wind Turbine in Cold Weather: A Preliminary Study

2003 ◽  
Vol 9 (1) ◽  
pp. 23-33 ◽  
Author(s):  
Christophe Leclerc ◽  
Christian Masson
Keyword(s):  
Wind Turbine ◽  
Air Temperature ◽  
High Power ◽  
Power Output ◽  
Cold Weather ◽  
Air Density ◽  
High Power Output ◽  
Wind Velocities ◽  
Preliminary Study ◽  
Narrow Bands

According to popular belief, air temperature effects on wind turbine power output are produced solely by air density variations, and power is proportional to air density. However, some cases have been reported, all involving stall-controlled wind turbines, in which unexpected high power output was observed at very low temperatures.As a preliminary study, this article intends to quantify the influence of air temperature on the power production of the Tacke TW600 wind turbine installed in Tiverton, Ontario, Canada. Increases in power output due to air temperature variation are stratified by wind velocity, showing that these increases are below the theoretical limits of air density variations during operation in low winds and are comparable to and beyond those theoretical limits at higher wind velocities. At – 9°C and 0°C, narrow bands of power at distinct levels are observed in the stall regime of the turbine; they are typical of many stall phenomena observed on stall-controlled rotors, but these levels have been found to be independent of any parameters recorded.

A new energy harvester design for high power output at low frequencies

2013 ◽  
Vol 199 ◽  
pp. 344-352 ◽  
Author(s):  
Lokesh Dhakar ◽  
Huicong Liu ◽  
F.E.H. Tay ◽  
Chengkuo Lee
Keyword(s):  
High Power ◽  
Power Output ◽  
Energy Harvester ◽  
Low Frequencies ◽  
High Power Output ◽  
New Energy

High-power output over 200 mW of 1.3 µm GaInAsP VIPS lasers

1987 ◽  
Vol 23 (6) ◽  
pp. 738-743 ◽  
Author(s):  
S. Oshiba ◽  
A. Matoba ◽  
M. Kawahara ◽  
Y. Kawai
Keyword(s):  
High Power ◽  
Power Output ◽  
High Power Output
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