4,465 research outputs found
Achieving ultrahigh instantaneous power density of 10 MW/m<sup>2</sup> by leveraging the opposite-charge-enhanced transistor-like triboelectric nanogenerator (OCT-TENG)
No full textConverting 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.</p
Slip distribution of the February 6, 2023 Mw 7.8 and Mw 7.6, Kahramanmaraş, Turkey earthquake sequence in the East Anatolian Fault Zone
No full textOn February 6, 2023, two large earthquakes occurred near the Turkish town of Kahramanmaraş. The moment magnitude (Mw) 7.8 mainshock ruptured a 310 km-long segment of the left-lateral East Anatolian Fault, propagating through multiple releasing step-overs. The Mw 7.6 aftershock involved nearby left-lateral strike-slip faults of the East Anatolian Fault Zone, causing a 150 km-long rupture. We use remote-sensing observations to constrain the spatial distribution of coseismic slip for these two events and the February 20 Mw 6.4 aftershock near Antakya. Pixel tracking of optical and synthetic aperture radar data of the Sentinel-2 and Sentinel-1 satellites, respectively, provide near-field surface displacements. High-rate Global Navigation Satellite System data constrain each event separately. Coseismic slip extends from the surface to about 15 km depth with a shallow slip deficit. Most aftershocks cluster at major fault bends, surround the regions of high coseismic slip, or extend outward of the ruptured faults. For the mainshock, rupture propagation stopped southward at the diffuse termination of the East Anatolian fault and tapered off northward into the Pütürge segment, some 20 km south of the 2020 Mw 6.8 Elaziğ earthquake, highlighting a potential seismic gap. These events underscore the high seismic potential of immature fault systems
Improvement of Output Performance of the TENG Based on PVDF by Doping Tourmaline
No full textThis work introduces a novel nanomaterial
to form microcapacitors
for the purpose of accumulating triboelectric charges and enhancing
the output properties of a triboelectric nanogenerator (TENG). Incorporating
tourmaline (TM) into electrospun poly(vinylidene fluoride) (PVDF)
nanofibers as a tribo-negative layer constructs a new TENG based on
PVDF/TM nanofibers. For the prepared TENG with 0.3 wt % TM nanofiller,
the power density reaches as high as 107 mW/m2 at the matched
4 MΩ external load, a remarkable 156% improvement over the power
density of the pure PVDF nanogenerator; at the same time, the open-circuit
voltage can reach 267 V. PVDF/TM nanofibers increase the output performance
of the TENG by 2.1 times. By tapping the TENG gently with a human
finger, it can directly light 13 LEDs and the TENG successfully powers
an electronic watch by harvesting energy. In the fibers, the PVDF
polymer chains form a cooperative and mutual alignment with the TM
owing to electrospinning, facilitating the highly polar crystalline
β-phase formation of PVDF. In addition, the addition of TM nanofillers
enhances the mechanical stability as well as mechanical properties
of PVDF nanofiber films. The high-performance TENG possesses high
application potential in the rapidly developing society to be a self-powered
system to provide efficient and renewable energy for portable electronic
devices
Comparative feasibility study of a 30 MW disruptive floater solution with a 15 MW PivotBuoy and a benchmark 15 MW semi-submersible floater in the Bay of Biscay
No full textThis paper investigates the technical, life cycle, and economic feasibility of a 30 MW upscaled downwind turbine, comparing it to a 15 MW X1 Wind PivotBuoy downwind turbine and a benchmark 15 MW IEA Umaine VolturnUS-S upwind turbine in the 450 MW Sud de la Bretagne I wind farm site. The study is significant due to the rising energy demand, the potential for decreasing the levelized cost of energy with increased turbine size, and the optimized use of space. The size limit of current upwind turbine designs could be addressed using a downwind turbine solution.The research is conducted by modelling the global dynamic response of the structure using OpenFAST and computing the natural frequencies and stresses using a finite element model. A lifecycle analysis is performed to identify potential pitfalls and bottlenecks by analysing the individual lifecycle phases. The economic feasibility is assessed by simulating the annual energy production using TOPFARM and utilizing structural analysis and lifecycle assessment to quantify capital, operational, and abandonment expenditures. Based on the annual energy production and the performance indicators the levelized cost of energy is calculated.The findings indicate that while the global stability is within boundaries, the stress in members is too high with a simple scale-up of the proposed design. Bottlenecks are found in lifting operations and supply chain readiness. The levelized cost of energy and capital expenditure increased due to substructure self-weight, rendering the proposed 30 MW scale-up currently unfeasible when compared to the other two wind farms.These findings are important as they demonstrate that the 15 MW X1 Wind PivotBuoy is not scalable without design changes. The levelized cost of energy does not decrease with an increased floater solution. The 15 MW X1 Wind PivotBuoy downwind turbine seems more economically viable, making it a more interesting option for future development.Civil Engineerin
Rotary freestanding ternary electrification layered triboelectric nanogenerator (Tel-Teng) for micro vertical axis wind turbine (VAWT)
No full textIn Partial Fulfilment of the Requirements for the Degree of Bachelor of Science in Mechanical EngineeringThe triboelectric nanogenerator (TENG) harvests ambient mechanical energy and converts it into electricity. TENGs can function through the triboelectrification mechanism. These contact electrifications will begin with a source of continuous mechanical motion. The wind is a renewable resource that can provide this continual mechanical motion. Wind turbines capture wind energy and use it to generate rotational mechanical energy. The rotary freestanding triboelectric layer-based TENGs utilize this. The output of freestanding TENGs has improved with ternary electrification layered-triboelectric nanogenerators (TEL-TENG). This study integrates the freestanding rotary TEL-TENG into any microscale vertical axis wind turbine (VAWT) that will allow power generation. It can use to run low-power devices. It utilizes Copper, FEP, and Kapton, which have promising properties as triboelectric materials. The prototype underwent thorough testing at different wind speeds in urban areas to prove its effectiveness. It yielded a minimum power of 4.396 mW at one (1) m/s wind speed and a maximum power of 523.8 mW at five (5) m/s wind speed and efficiencies with a minimum value of 27% at four (4) m/s wind speed and a maximum value of 46.63% at three (3) m/s wind speed
Durable Self-Powered Wireless IoT Machine Condition Monitoring System Based on an Auto-Switching Non-Contact Centrifugal TENG
No full textThe long-term intelligent machine condition monitoring system is essential in improving maintenance costs and decision-making. Triboelectric nanogenerator (TENG) has a great advantage in developing self-powered machine condition monitoring. The main issues preventing TENG for such applications are poor integration to machine components, limited operational range, and weak durability. In this work, durable non-contact TENG energy harvester adaptive is designed to mechanical shafts for harvesting rotational energy. The harvester is designed to automatically switch to the non-contact mode by using centrifugal force to avoid manual switching while operating over a wide range of speeds of 0–2000 rpm. The designed TENG generates a high output of up to 25 mW with excellent stability for >20 days of continuous operation and exhibits a high-power density of 286 W m−3. Moreover, a self-powered long-term continuous condition monitoring system is developed from a TENG sensor, energy harvester, and wireless module. The developed system successfully sends possible machine fault frequency every 74 min to the cloud and accessible anywhere. This is the only TENG design reported in the literature that can fully power a Wi-Fi module to send data. Hence, the result promises the practical application of the system in developing internet of things (IoT) in the Industry.Validerad;2025;Nivå 2;2025-05-23 (u2);Full text license: CC BY 4.0;</p
Insight into Cigarette Wrapper and Electroactive Polymer Based Efficient TENG as Biomechanical Energy Harvester for Smart Electronic Applications
No full textHere, we demonstrated
an arc shaped flexible triboelectric nanogenerator (TENG) that efficiently
harvests asymmetrical mechanical energy for powering several portable
electronic devices. Here the fabrication of TENG is based on the integration
of a cigarette wrapper, spongelike poly(vinylidene fluoride) (PVDF)
film, and conducting carbon tape. Here, the spongelike PVDF film was
prepared through nonsolvent induced phase separation (NIPS) technique
(by simply spraying PVDF solution on a water surface in a Petri dish).
Owing to the low density of the PVDF sponge and the cigarette wrapper,
the final device with a volume of 6.6 cm3 shows a total
mass of 1.259 g. The fabricated TENG exhibits open circuit voltage
of ∼342 V and short circuit current of ∼8.1 μA
on frequencies of ∼3.4 Hz without electrospinning and poling
treatment under finger tapping, which gives a maximum area power density
of ∼0.37 mW/cm2 at a load resistance of 40 MΩ.
The TENG shows excellent durability without any change in output performance
successively for 7 days (193200 cycles). Also, this device directly
lit up 136 commercial LEDs instantly without any rectification unit
and sensed different types of mechanical forces. With easy fabrication
and cost-effective technique, this work paves a new and smart way
to fabricate high performance TENG for powering portable electronic
appliances
Insight into Cigarette Wrapper and Electroactive Polymer Based Efficient TENG as Biomechanical Energy Harvester for Smart Electronic Applications
No full textHere, we demonstrated
an arc shaped flexible triboelectric nanogenerator (TENG) that efficiently
harvests asymmetrical mechanical energy for powering several portable
electronic devices. Here the fabrication of TENG is based on the integration
of a cigarette wrapper, spongelike poly(vinylidene fluoride) (PVDF)
film, and conducting carbon tape. Here, the spongelike PVDF film was
prepared through nonsolvent induced phase separation (NIPS) technique
(by simply spraying PVDF solution on a water surface in a Petri dish).
Owing to the low density of the PVDF sponge and the cigarette wrapper,
the final device with a volume of 6.6 cm3 shows a total
mass of 1.259 g. The fabricated TENG exhibits open circuit voltage
of ∼342 V and short circuit current of ∼8.1 μA
on frequencies of ∼3.4 Hz without electrospinning and poling
treatment under finger tapping, which gives a maximum area power density
of ∼0.37 mW/cm2 at a load resistance of 40 MΩ.
The TENG shows excellent durability without any change in output performance
successively for 7 days (193200 cycles). Also, this device directly
lit up 136 commercial LEDs instantly without any rectification unit
and sensed different types of mechanical forces. With easy fabrication
and cost-effective technique, this work paves a new and smart way
to fabricate high performance TENG for powering portable electronic
appliances
Insight into Cigarette Wrapper and Electroactive Polymer Based Efficient TENG as Biomechanical Energy Harvester for Smart Electronic Applications
No full textHere, we demonstrated
an arc shaped flexible triboelectric nanogenerator (TENG) that efficiently
harvests asymmetrical mechanical energy for powering several portable
electronic devices. Here the fabrication of TENG is based on the integration
of a cigarette wrapper, spongelike poly(vinylidene fluoride) (PVDF)
film, and conducting carbon tape. Here, the spongelike PVDF film was
prepared through nonsolvent induced phase separation (NIPS) technique
(by simply spraying PVDF solution on a water surface in a Petri dish).
Owing to the low density of the PVDF sponge and the cigarette wrapper,
the final device with a volume of 6.6 cm3 shows a total
mass of 1.259 g. The fabricated TENG exhibits open circuit voltage
of ∼342 V and short circuit current of ∼8.1 μA
on frequencies of ∼3.4 Hz without electrospinning and poling
treatment under finger tapping, which gives a maximum area power density
of ∼0.37 mW/cm2 at a load resistance of 40 MΩ.
The TENG shows excellent durability without any change in output performance
successively for 7 days (193200 cycles). Also, this device directly
lit up 136 commercial LEDs instantly without any rectification unit
and sensed different types of mechanical forces. With easy fabrication
and cost-effective technique, this work paves a new and smart way
to fabricate high performance TENG for powering portable electronic
appliances
Short-circuit characteristics of superconducting permanent magnet generators for 10 MW wind turbines
No full textSuperconducting permanent magnet generators (SCPMGs) are a potential candidate for 10 MW direct-drive wind turbine applications. This paper presents two 10 MW SCPMG designs using MgB&lt;sub&gt;2&lt;/sub&gt; cables for the armature winding and investigates the short-circuit characteristics of the designed SCPMGs. The first part of the results shows that the SCPMGs can double the shear stress of a conventional low-speed permanent magnet (PM) generator (from 65 kPa to 130 kPa) whilst avoiding demagnetization of the PMs in rated-load operation. However, the power factor has to drop to a range of 0.7-0.8. The second part of the results shows that during a sudden three-phase short circuit, the superconducting armature winding is prone to quench and the PMs are likely to be demagnetized in both proposed designs.Accepted Author ManuscriptTransport Engineering and Logistic
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