3D-architected carbon microtubule aerogel based phase change composite for multi-field-responsive high-efficiency energy conversion

Till date, fabrication of piezoelectric nanogenerator (PNG) with highly durable, high power density, and high energy conversion efficiency is of great concern. Here a flexible, sensitive, cost effective hybrid piezoelectric nanogenerator (HPNG) developed by integrating flexible steel woven fabric electrodes into poly(vinylidene fluoride) (PVDF)/aluminum oxides decorated reduced graphene oxide (AlO‐rGO) nanocomposite film is reported where AlO‐rGO acts as nucleating agent for electroactive β‐phase formation. The HPNG exhibits reliable energy harvesting performance with high output, fast charging capability, and high durability compared with previously reported PVDF based PNGs. This HPNG is capable for harvesting energy from a variety and easy accessible biomechanical and mechanical energy sources such as, body movements (e.g., hand folding, jogging, heel pressing, and foot striking, etc.) and machine vibration. The HPNG exhibits high output power density and energy conversion efficiency, facilitating direct light on different color of several commercial light‐emitting diodes instantly and powers up many portable electronic devices like wrist watch, calculator, speaker, and mobile liquid crystal display (LCD) screen through capacitor charging. More importantly, HPNG retains its performance after long compression cycles (≈158 400), demonstrating great promise as a piezoelectric energy harvester toward practical applications in harvesting biomechanical and mechanical energy for self‐powered systems.

As a new technology for harvesting distributed energy, the triboelectric nanogenerator (TENG) has been widely used in harvesting wind energy. However, the wind-driven TENG (WD-TENG) faces the problems of high frictional resistance and low mechanical energy conversion efficiency. Here, based on optimizing the structure of the wind turbine, a rotational double-electrode-layer WD-TENG (DEL-WD-TENG) is developed. When the rotational speed is less than 400 round per minute (rpm), the dielectric triboelectric layer rubs with the inner electrode layer under its gravity; when the rotational speed is higher than 400 rpm, the dielectric triboelectric layer rubs with the outer electrode layer under the centrifugal force. The double-electrode-layer structure avoids the energy loss caused by other forces except gravity, centrifugal, and electrostatic adsorption, which improves the mechanical energy conversion efficiency and prolongs the working life of the DEL-WD-TENG. The conversion efficiency from mechanical energy to electricity of the DEL-WD-TENG can reach 10.3%. After 7 million cycles, the transferred charge of the DEL-WD-TENG is reduced by about 5.0%, and the mass loss of dielectric triboelectric layer is only 5.6%. The DEL-WD-TENG with low frictional resistance and high energy conversion efficiency has important application prospects in wind energy harvesting and self-powered sensing systems.

An inertial rotary energy harvester for vibrations at ultra-low frequency with high energy conversion efficiency

Effective passivation of TiO2/Si by interlayer SiOx controlled by scanning zone annealing for perovskite/Si tandem solar cell

Bio-waste onion skin as an innovative nature-driven piezoelectric material with high energy conversion efficiency

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 487:123-133 (2013) - DOI: https://doi.org/10.3354/meps10390 Patchy zooplankton grazing and high energy conversion efficiency: ecological implications of sandeel behavior and strategy Mikael van Deurs*, Asbjørn Christensen, Anna Rindorf DTU Aqua National Institute of Aquatic Resources, Technical University of Denmark (DTU), Jægersborg Alle 1, Charlottenlund Castle, 2920 Charlottenlund, Denmark *Email: mvd@aqua.dtu.dk ABSTRACT: Sandeels display strong site fidelity and spend most of their life buried in the seabed. This strategy carries important ecological implications. Sandeels save energy when they are not foraging, but in return are unable to move substantially and may therefore be sensitive to local depletion of prey. We studied zooplankton consumption and energy conversion efficiency of the lesser sandeel Ammodytes marinus in the central North Sea, using stomach data, length and weight-at-age data, bioenergetics, and hydrodynamic modeling. The results suggested the following. (1) Lesser sandeels in the Dogger area depend largely on relatively large copepods in early spring. (2) The lesser sandeel is an efficient converter, making secondary production into fish tissue available for higher trophic levels. Hence, changes in species composition towards a more herring-dominated system, as seen in recent times, may lead to a decrease in system transfer efficiency. (3) Sandeels leave footprints in the standing copepod biomass as far as 100 km from the edge of their habitat, but smaller and more isolated sandeel habitat patches have a much lower impact than larger patches, suggesting that smaller habitats can sustain higher sandeel densities and growth rates per area than larger habitats. We conclude that sandeel behavior and strategy have ecosystem implications. KEY WORDS: Sand lance · Food web · Trophic transfer efficiency · Bioenergetics · Growth · Food consumption · North Sea · Dogger Full text in pdf format PreviousNextCite this article as: van Deurs M, Christensen A, Rindorf A (2013) Patchy zooplankton grazing and high energy conversion efficiency: ecological implications of sandeel behavior and strategy. Mar Ecol Prog Ser 487:123-133. https://doi.org/10.3354/meps10390 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 487. Online publication date: July 30, 2013 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2013 Inter-Research.

Solution-processable perovskites show highly emissive and good charge transport, making them attractive for low-cost light-emitting diodes (LEDs) with high energy conversion efficiencies. Despite recent advances in device efficiency, the stability of perovskite LEDs is still a major obstacle. Here, we demonstrate stable and bright perovskite LEDs with high energy conversion efficiencies by optimizing formamidinium lead iodide films. Our LEDs show an energy conversion efficiency of 10.7%, and an external quantum efficiency of 14.2% without outcoupling enhancement through controlling the concentration of the precursor solutions. The device shows low efficiency droop, i.e. 8.3% energy conversion efficiency and 14.0% external quantum efficiency at a current density of 300 mA cm−2, making the device more efficient than state-of-the-art organic and quantum-dot LEDs at high current densities. Furthermore, the half-lifetime of device with benzylamine treatment is 23.7 hr under a current density of 100 mA cm−2, comparable to the lifetime of near-infrared organic LEDs.

This Perspective first briefly summarizes the progress of superwettability research in the group over the past 25 years, starting by studying the effect of nanostructure and micro/nanostructure on surface wettability. The intrinsic wetting thresholds for different liquids according to the transition point of superlyophilicty and superlyophobicity on nanostructured surface are experimentally determined, and over 10 superwetting interfacial materials are invented. Recently, the study of dynamic superwettability is focused, which refers to the property of liquids superspreading on 1D or 2D surfaces with micro/nano structures, or partial ordered flow in micro/nano channels, and even the ordered flow of ions and molecules in biological ion channels/water channels/enzyme channels. Furthermore, a crucial question in life science is raised: how can life systems achieve ultralow energy consumption (UEC) in high-efficiency bio-synthesis, energy conversion, and information transmission? It is revealed that the ordered directional collective motion of ions/molecules in biological nanochannels is the physicochemical essence to achieve these UEC processes, and provides a summary and perspective on high-efficiency bio-synthesis, energy conversion, and information transmission in artificial systems.

A new insight towards eggshell membrane as high energy conversion efficient bio-piezoelectric energy harvester

With global warming and an increase in extreme weather, reducing carbon emissions in response to climate change has become a global consensus. Compared with traditional fuel vehicles, hybrid vehicles have the benefits of energy savings, low grid-load, and low emissions. The hybrid vehicles use the internal combustion engine and lithium-ion batteries as the hybrid power source to achieve the best match between the engine and the motor. However, the current commercial hybrid vehicle still has such defects as high dependence on fossil fuels, high carbon emissions, poor safety, etc. As such, it is necessary to explore and develop the next generation low-carbon hybrid vehicles. Herein, we propose a new-type hybrid of ammonia fuel cell and internal combustion engine with high-energy conversion efficiency and low-carbon emissions. Considering the advantages of low-carbon emissions, high mileage, fast refueling, low-cost, high-energy conversion efficiency, and high safety, a green low-carbon concept of the ammonia fuel cell-internal combustion engine hybrid vehicle (AFC-ICE HV) is proposed. This will help improve the scale and efficiency of China's green energy conversion, establish a green, low-carbon and sustainable economic system, provide new impetus for tackling climate change and environmental protection recovery, and help China and the world to achieve the Carbon Peak and Carbon Neutrality goal.

Life systems present ultralow energy consumption in high-efficiency energy conversion, information transmission, and biosynthesis. The total energy intake of the human body is about 2000 kcal/day to maintain all of our activities, which is comparable to a power of ∼100 W. The energy required for the brain to work is equivalent to ∼20 W, and the rest of the energy (∼80 W) is used for other activities. All in vivo biosyntheses take place only at body temperature, which is much lower than that of in vitro reactions. To achieve these ultralow energy-consumption processes, there should be a kind of ultralow-resistivity matter transport in nanochannels (e.g., ionic and molecular channels), in which the directional collective motion of ions or molecules is a necessary condition rather than traditional Newton diffusion. The directional collective motion of ions and molecules is considered to be ionic/molecular superfluidity. The driving force of ionic/molecular superfluidity formation requires two necessary conditions: (1) Ions or molecules are confined at a certain distance (e.g., approximately twice Debye length (2λD) for ions or twice the van der Waals equilibrium distance (2d0) for molecules). (2) When the attractive potential energy (E0) is stronger than the thermal noise (kBTc), ionic/molecular superfluidity can be formed. The concept of ionic/molecular superfluidity will promote the understanding of energy conversion with ultralow energy consumption in biological systems. The swing of an eel's body generating electricity and cardiac resuscitation denote the conversion from mechanical energy to electrical energy, and mechanical modulation might result in a coherent resonance of ionic motion. The coherent resonance of Ca2+ in myocardium cells can induce a heartbeat, realizing the conversion from the electrical energy to the mechanical energy of a biological system. The macroscopic quantum state of ion channels is considered to be a carrier of neural information, and the environment field might play a significant role in regulating the macroscopic quantum states of various ion channels. In the biological ion channels system, the coupling of ion channels and their released photons might induce an environment wave which in turn regulates the ion oscillations in the channels to a coherent state. The states of decoherence and coherence might correspond to the states of sleep and action. We also demonstrated the decomposition of ATP to ADP released photons with a frequency of ∼34 THz, which could further drive DNA polymerization in the nanocavity of DNA polymerase. The photochemical (mid- and far-IR) reaction might be the driving force in high-efficiency biosynthesis. Quantized syntheses resonantly driven by multiple mid- and far-IR photons could be further designed in a tubular reactor with membranes of different microporous structures to achieve a high-efficiency synthesis with a low energy consumption. Finally, we point out that the Bose-Einstein condensate potentially widely exists. We expect that this Account will provide new ideas for the key problem in life science: how can life systems present ultralow energy consumption in high-efficiency energy conversion, information transmission, and biosynthesis?

Developing narrow-band-gap ferroelectric semiconducting photocatalysts is a promising strategy for efficient photocatalytic water splitting with high energy conversion efficiency. Within this context, six ferro/nonferroelectric vertical heterostructure superlattices (VHSs) are constructed in this work by stacking ferroelectric SiS or GeS with nonferroelectric layered organic photocatalysts (C2N, g-C3N4, and melon), layer by layer. The geometry and electronic structures of these six VHSs are systematically investigated by density functional theory calculations. Consequently, four VHSs (SiS/g-C3N4, GeS/C2N, GeS/g-C3N4, and GeS/melon) are predicted to simultaneously possess several important and highly desirable features for photocatalytic water splitting, namely excellent visible-light adsorption, remarkable spontaneous polarization (0.49-0.70 C/m2), spatial charge separation, as well as suitable band-edge positions, thus serving as potential candidates for photocatalytic water splitting to produce hydrogen. This work not only provides a new strategy to use narrow-band-gap ferroelectric semiconductors for photocatalytic water splitting but also offers inspiration for developing photocatalysts with high energy conversion efficiency.

Electrocatalytic CO2 reduction (CO2RR) to valuable fuels is a promising approach to mitigate energy and environmental problems, but controlling the reaction pathways and products remains challenging. Here a novel Cu2O nanoparticle film was synthesized by square-wave (SW) electrochemical redox cycling of high-purity Cu foils. The cathode afforded up to 98% Faradaic efficiency for electroreduction of CO2 to nearly pure formate under ≥45 atm CO2 in bicarbonate catholytes. When this cathode was paired with a newly developed NiFe hydroxide carbonate anode in KOH/borate anolyte, the resulting two-electrode high-pressure electrolysis cell achieved high energy conversion efficiencies of up to 55.8% stably for long-term formate production. While the high-pressure conditions drastically increased the solubility of CO2 to enhance CO2 reduction and suppress hydrogen evolution, the (111)-oriented Cu2O film was found to be important to afford nearly 100% CO2 reduction to formate. The results have implications for CO2 reduction to a single liquid product with high energy conversion efficiency.

Triboelectric nanogenerator (TENG) as a new energy harvester has attracted significant attention due to its excellent output performance and high energy conversion efficiency at low-frequency, small-amplitude and weak-force compared with a traditional electromagnetic generator. Here, an ultraweak mechanical stimuli actuated single electrode triboelectric nanogenerator (UMA-TENG) has been studied with an atomic force microscope. The electrical output and force curve of UMA-TENG were studied at first, as well as the maximum output performance and highest energy conversion efficiency. Then the influence of the driving frequency, separation distance and motion amplitude was investigated, respectively. Moreover, by introducing an external switch to reach a cycle of maximized energy output, the maximum energy conversion efficiency of the UMA-TENG was up to 73.6% with an input mechanical energy of 48 pJ. This work demonstrates that the TENG shows excellent performance in ultraweak mechanical stimuli and could broaden the applications of the TENG in sensors, actuators, micro-robotics, micro-electro-mechanical-systems, and wearable electronics.

Integrated Natural Gas Liquids/Nitrogen Rejection Unit (NGL/NRU) technology will be utilised for the first time in Qatar on the Barzan Gas Project, which is a joint venture project between Qatar Petroleum (QP) and ExxonMobil Barzan Limited. The North Field Reservoir, which supplies the Barzan Gas Project, contains a high content of inerts, e.g., nitrogen and helium. One challenge was to identify a technology to achieve the required specifications of the sales gas by rejecting the inerts from the feed gas. RasGas initiated a study to evaluate process licensors' capability to supply an integrated process design for recovering NGL and rejecting nitrogen for the Barzan Gas Project. The requirements are to recover the NGL product stream, containing 95% of the incoming ethane content and essentially 100 per cent of the propane and heavier (C3+) hydrocarbons. One primary component of the technology is to reject nitrogen from the gas stream to achieve an acceptable BTU content and Wobbe Index to meet QP sales gas specifications. To achieve the above requirements, Chart Energy and Chemicals Inc, as a technology licensor, demonstrated the ability to provide an integrated NGL/NRU licensed process with the following merits:Utilises a proven Brazed Aluminum Heat Exchanger (BAHX) supplier.Takes advantage of the available feed pressure to minimise overall energy consumption without requiring excessiveAluminum / surface area.Utilises high efficiency compression to meet final sales gas delivery requirements.Minimises footprint and plant congestion by installing equipment within sealed cold boxes.Provides a simple exchanger arrangement for easy conversion to various modes of operation. Introduction Natural gas is considered a valuable source of clean energy, as it emits lower quantities of greenhouse gases than other fossil fuels, and is also used as a feedstock to chemical plants. 'In addition, when comparing natural gas with other hydrocarbon energy sources, it is the most hydrogen-rich and has higher energy conversion efficiencies '(1). Natural gas consists primarily of methane as the main element, but it also contains considerable amounts of light and heavier hydrocarbons as well as contaminating compounds of carbon dioxide, nitogen, mercury, helium and hydrogen sulfide (CO2, N2, Hg, He, H2S, etc). Before transporting the gas over long distances to end users, it is necessary to remove all impurities to achieve the required product specifications.