Theoretical Fundamentals of the Discrete Operational Lifetime

2020 ◽  
Vol 49 (3) ◽  
pp. 206-213
Author(s):  
G. S. Sadykhov ◽  
S. S. Kudryavtseva
Keyword(s):  
Operational Lifetime

Satellite Altimeter Results Over East Antarctica

1982 ◽  
Vol 3 ◽  
pp. 32-35 ◽  
Author(s):  
R. L. Brooks
Keyword(s):  
Tracking System ◽  
Ice Sheet ◽  
East Antarctica ◽  
Satellite Altimeter ◽  
Ice Shelves ◽  
Ice Surface ◽  
Operational Lifetime ◽  
Waveform Retracking ◽  
Better Than

During the operational lifetime of the Seasat altimeter from 3 July to 10 October 1978, more than 450 overflights were made over East Antarctica inland to latitude 72°S. An analysis of selected passes over a variety of ice features demonstrates that the oceanographic altimeter performed surprisingly well over the ice sheet and ice shelves, acquiring useful measurements during approximately 70% of each pass. The altimeter's onboard tracking system dampened out the ice-surface elevations, but post-flight retracking of the stored return waveforms reveals excellent ice-surface details. After waveform retracking, the altimeter repeatability is better than ±1 m.

scholarly journals Protecting Benzylic CH Bonds by Deuteration Doubles the Operational Lifetime of Deep‐Blue Ir‐Phenylimidazole Dopants in Phosphorescent OLEDs (Advanced Optical Materials 16/2021)

2021 ◽  
Vol 9 (16) ◽  
pp. 2170059
Author(s):  
Hye Jin Bae ◽  
Jong Soo Kim ◽  
Alexander Yakubovich ◽  
Jinhoon Jeong ◽  
Sangho Park ◽  
...  
Keyword(s):  
Optical Materials ◽  
Deep Blue ◽  
Operational Lifetime

scholarly journals Phenylalkylammonium passivation enables perovskite light emitting diodes with record high-radiance operational lifetime: the chain length matters

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yuwei Guo ◽  
Sofia Apergi ◽  
Nan Li ◽  
Mengyu Chen ◽  
Chunyang Yin ◽  
...  
Keyword(s):  
Chain Length ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Light Emitting Diodes ◽  
Surface Defects ◽  
Theoretical Modelling ◽  
Ion Migration ◽  
Light Emitting ◽  
Operational Lifetime ◽  
Chain Lengths

AbstractPerovskite light emitting diodes suffer from poor operational stability, exhibiting a rapid decay of external quantum efficiency within minutes to hours after turn-on. To address this issue, we explore surface treatment of perovskite films with phenylalkylammonium iodide molecules of varying alkyl chain lengths. Combining experimental characterization and theoretical modelling, we show that these molecules stabilize the perovskite through suppression of iodide ion migration. The stabilization effect is enhanced with increasing chain length due to the stronger binding of the molecules with the perovskite surface, as well as the increased steric hindrance to reconfiguration for accommodating ion migration. The passivation also reduces the surface defects, resulting in a high radiance and delayed roll-off of external quantum efficiency. Using the optimized passivation molecule, phenylpropylammonium iodide, we achieve devices with an efficiency of 17.5%, a radiance of 1282.8 W sr−1 m−2 and a record T50 half-lifetime of 130 h under 100 mA cm−2.

scholarly journals Protecting Benzylic CH Bonds by Deuteration Doubles the Operational Lifetime of Deep‐Blue Ir‐Phenylimidazole Dopants in Phosphorescent OLEDs

2021 ◽  
pp. 2100630
Author(s):  
Hye Jin Bae ◽  
Jong Soo Kim ◽  
Alexander Yakubovich ◽  
Jinhoon Jeong ◽  
Sangho Park ◽  
...  
Keyword(s):  
Deep Blue ◽  
Operational Lifetime

Remarkable lifetime improvement of quantum-dot light emitting diodes by incorporating rubidium carbonate in metal-oxide electron transport layers

2019 ◽  
Vol 7 (32) ◽  
pp. 10082-10091 ◽  
Author(s):  
Yujin Lee ◽  
Hyo-Min Kim ◽  
Jeonggi Kim ◽  
Jin Jang
Keyword(s):  
Electron Transport ◽  
Quantum Dot ◽  
Metal Oxide ◽  
Light Emitting Diodes ◽  
Light Emitting ◽  
Remarkable Improvement ◽  
Operational Lifetime ◽  
Electron Transporting Layer ◽  
Doped Zno ◽  
Mg Doped

We demonstrated the remarkable improvement of efficiency roll-off and operational lifetime in red quantum dot light emitting diodes (R-QLEDs) by incorporating rubidium carbonate (Rb2CO3) in Mg doped ZnO (MZO) electron transporting layer (ETL).

Surface Micromachined Electrothermal V-Beam Micromotors

2001 ◽  
Author(s):  
David S. Schreiber ◽  
Wei-Jen Cheng ◽  
John M. Maloney ◽  
Don L. DeVoe
Keyword(s):  
Theoretical Model ◽  
Driving Voltage ◽  
Operational Lifetime ◽  
Motor Design ◽  
Model Reliability

Abstract Surface micromachined electrothermal V-beam microactuators have been investigated and integrated into a microstepper motor design. 2 μm thick, 2 μm wide, 400 μm long polysilicon microactuators were fabricated and tested for displacement and operational lifetime. Displacement results compare well to a theoretical model. Reliability of the microactuators was also evaluated. Arrays of electrothermal V-beam microactuators were developed to provide actuation for novel microstepper motor designs. Motor displacement and speed have been measured, with repeatable 3.2 μm and 2.5 μm step sizes for forward and reverse directions for a driving voltage of 8 V and frequencies up to 1000 Hz. Maximum speeds of 4200 μm/sec and 3100 μm/sec were observed at 8 V and 1800 Hz for forward and reverse operation.

scholarly journals New Pulse Width Modulation Technique to Reduce Losses for Three-Phase Photovoltaic Inverters

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Mohannad Jabbar Mnati ◽  
Dimitar V. Bozalakov ◽  
Alex Van den Bossche
Keyword(s):  
Control Strategy ◽  
Pulse Width Modulation ◽  
Photovoltaic System ◽  
Pv System ◽  
Total Cost ◽  
Switching Losses ◽  
Three Phase ◽  
Operational Lifetime ◽  
Term Energy ◽  
Dc Bus

Nowadays, most three-phase, “off the shelf” inverters use electrolytic capacitors at the DC bus to provide short term energy storage. However, this has a direct impact on inverter lifetime and the total cost of the photovoltaic system. This article proposes a novel control strategy called a 120° bus clamped PWM (120BCM). The 120BCM modulates the DC bus and uses a smaller DC bus capacitor value, which is typical for film capacitors. Hence, the inverter lifetime can be increased up to the operational lifetime of the photovoltaic panels. Thus, the total cost of ownership of the PV system will decrease significantly. Furthermore, the proposed 120BCM control strategy modulates only one phase current at a time by using only one leg to perform the modulation. As a result, switching losses are significantly reduced. The full system setup is designed and presented in this paper with some practical results.

scholarly journals Non-fullerene acceptor organic photovoltaics with intrinsic operational lifetimes over 30 years

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yongxi Li ◽  
Xiaheng Huang ◽  
Kan Ding ◽  
Hafiz K. M. Sheriff ◽  
Long Ye ◽  
...  
Keyword(s):  
High Efficiency ◽  
Bulk Heterojunction ◽  
Low Cost ◽  
Accelerated Aging ◽  
Outdoor Exposure ◽  
Buffer Layers ◽  
Organic Photovoltaic ◽  
Light Illumination ◽  
Energy Technology ◽  
Operational Lifetime

AbstractOrganic photovoltaic cells (OPVs) have the potential of becoming a productive renewable energy technology if the requirements of low cost, high efficiency and prolonged lifetime are simultaneously fulfilled. So far, the remaining unfulfilled promise of this technology is its inadequate operational lifetime. Here, we demonstrate that the instability of NFA solar cells arises primarily from chemical changes at organic/inorganic interfaces bounding the bulk heterojunction active region. Encapsulated devices stabilized by additional protective buffer layers as well as the integration of a simple solution processed ultraviolet filtering layer, maintain 94% of their initial efficiency under simulated, 1 sun intensity, AM1.5 G irradiation for 1900 hours at 55 °C. Accelerated aging is also induced by exposure of light illumination intensities up to 27 suns, and operation temperatures as high as 65 °C. An extrapolated intrinsic lifetime of > 5.6 × 104 h is obtained, which is equivalent to 30 years outdoor exposure.

1000 h Operational Lifetime Perovskite Solar Cells by Ambient Melting Encapsulation

2020 ◽  
Vol 10 (9) ◽  
pp. 1902472 ◽  
Author(s):  
Sai Ma ◽  
Yang Bai ◽  
Hao Wang ◽  
Huachao Zai ◽  
Jiafeng Wu ◽  
...  
Keyword(s):  
Solar Cells ◽  
Perovskite Solar Cells ◽  
Operational Lifetime
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