Hierarchical-morphology metafabric for scalable passive daytime radiative cooling

Science ◽  
2021 ◽  
pp. eabi5484
Author(s):  
Shaoning Zeng ◽  
Sijie Pian ◽  
Minyu Su ◽  
Zhuning Wang ◽  
Maoqi Wu ◽  
...  
Keyword(s):  
High Performance ◽  
Large Scale ◽  
Global Climate ◽  
Solar Spectrum ◽  
Radiative Cooling ◽  
Practical Application ◽  
Atmospheric Window ◽  
The Cost ◽  
Hierarchical Morphology ◽  
Cooling Ability

Incorporating passive radiative cooling structures into personal thermal management technologies could effectively defend human against the intensifying global climate change. We show that large scale woven metafabrics can provide high emissivity (94.5%) in the atmospheric window and reflectivity (92.4%) in the solar spectrum because the hierarchical-morphology design of the randomly dispersed scatterers throughout the metafabric. Through scalable industrial textile manufacturing routes, our metafabrics exhibit excellent mechanical strength, waterproofness, and breathability for commercial clothing while maintaining efficient radiative cooling ability. Practical application tests demonstrated the human body covered by our metafabric could be cooled down ~4.8°C lower than that covered by commercial cotton fabric. The cost-effectiveness and high-performance of our metafabrics present great advantages for intelligent garments, smart textiles, and passive radiative cooling applications.

scholarly journals Simple Double-Layer Coating for Efficient Daytime and Nighttime Radiative Cooling

Atmosphere ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1198
Author(s):  
Mourad Benlattar ◽  
Issam Ibourk ◽  
Rahma Adhiri
Keyword(s):  
Double Layer ◽  
Large Scale ◽  
Outer Space ◽  
Solar Spectrum ◽  
Bottom Layer ◽  
Solar Irradiation ◽  
Radiative Cooling ◽  
Atmospheric Window ◽  
Thermal Emitters ◽  
Layer Coating

The passive radiative cooling approach refers to the physical process that pumps heat into outer space via the atmospheric window (8–13 μm) without energy input. The ability to continuously adjust the emissivity of thermal emitters in the sky window while maintaining high reflectivity in the solar spectrum remains a challenge. In order to achieve this task, a novel design referred to as double-layer nanoparticle-based coating is proposed. Our proposed emitter is appropriate for both high solar reflection and strong mid-infrared emissivity. The bottom and top layers are Al2O3 embedded with Ni nanoparticles and a super-hydrophilic TiO2-SiO2 layer. The bottom layer is designed to achieve high emissivity in “the atmospheric transparency window”. The top layer is designed to block solar illumination and to favor an enhanced cleanability of the coated design. Our double-layer coating as an optical solar reflector has excellent solar irradiation ( and is strongly emissive (0.97) across the “full sky window” at room temperature. Furthermore, a detailed numerical energy study has been performed, evaluating the temperature reduction and the radiative cooling performance under different conditions. The proposed simple coating can be used as an efficient radiative cooler on a large scale for energy conservation and thermoelectric devices.

scholarly journals Performance simulation of polymer-based nanoparticle and void dispersed photonic structures for radiative cooling

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jay Prakash Bijarniya ◽  
Jahar Sarkar ◽  
Pralay Maiti
Keyword(s):  
Fdtd Method ◽  
Solar Spectrum ◽  
Thermal Infrared ◽  
Performance Estimation ◽  
Radiative Cooling ◽  
Slab Thickness ◽  
Slight Variation ◽  
Performance Simulation ◽  
Atmospheric Window ◽  
Substrate Independent

AbstractPassive radiative cooling is an emerging field and needs further development of material. Hence, the computational approach needs to establish for effective metamaterial design before fabrication. The finite difference time domain (FDTD) method is a promising numerical strategy to study electromagnetic interaction with the material. Here, we simulate using the FDTD method and report the behavior of various nanoparticles (SiO2, TiO2, Si3N4) and void dispersed polymers for the solar and thermal infrared spectrums. We propose the algorithm to simulate the surface emissive properties of various material nanostructures in both solar and thermal infrared spectrums, followed by cooling performance estimation. It is indeed found out that staggered and randomly distributed nanoparticle reflects efficiently in the solar radiation spectrum, become highly reflective for thin slab and emits efficiently in the atmospheric window (8–13 µm) over the parallel arrangement with slight variation. Higher slab thickness and concentration yield better reflectivity in the solar spectrum. SiO2-nanopores in a polymer, Si3N4 and TiO2 with/without voids in polymer efficiently achieve above 97% reflection in the solar spectrum and exhibits substrate independent radiative cooling properties. SiO2 and polymer combination alone is unable to reflect as desired in the solar spectrum and need a highly reflective substrate like silver.

scholarly journals A Pragmatic and High-Performance Radiative Cooling Coating with Near-Ideal Selective Emissive Spectrum for Passive Cooling

Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 144 ◽  
Author(s):  
Mingxue Chen ◽  
Wenqing Li ◽  
Shuang Tao ◽  
Zhenggang Fang ◽  
Chunhua Lu ◽  
...  
Keyword(s):  
High Performance ◽  
Large Scale ◽  
Low Cost ◽  
Passive Cooling ◽  
Radiative Cooling ◽  
Test Results ◽  
External Energy ◽  
Functional Nanoparticles ◽  
Space Cooling ◽  
The Universe

Radiative cooling is a passive cooling technology that can cool a space without any external energy by reflecting sunlight and radiating heat to the universe. Current reported radiative cooling techniques can present good outside test results, however, manufacturing an efficient radiative material which can be applied to the market for large-scale application is still a huge challenge. Here, an effective radiative cooling coating with a near-ideal selective emissive spectrum is prepared based on the molecular vibrations of SiOx, mica, rare earth silicate, and molybdate functional nanoparticles. The radiative cooling coating can theoretically cool 45 °C below the ambient temperature in the nighttime. Polyethylene terephthalate (PET) aluminized film was selected as the coating substrate for its flexibility, low cost, and extensive production. As opposed to the usual investigations that measure the substrate temperature, the radiative cooling coating was made into a cubic box to test its space cooling performance on a rooftop. Results showed that a temperature reduction of 4 ± 0.5 °C was obtained in the nighttime and 1 ± 0.2 °C was achieved in the daytime. Furthermore, the radiative cooling coating is resistant to weathering, fouling, and ultraviolet radiation, and is capable of self-cleaning due to its hydrophobicity. This practical coating may have a significant impact on global energy consumption.

Design of wide-band dual–polarized aperture array antennas

2012 ◽  
Vol 4 (3) ◽  
pp. 373-378 ◽  
Author(s):  
Yongwei Zhang ◽  
Anthony K. Brown
Keyword(s):  
High Performance ◽  
Large Scale ◽  
Wide Band ◽  
Array Antennas ◽  
Wide Range ◽  
Square Kilometer Array ◽  
Aperture Array ◽  
Dual Polarized ◽  
Rf Performance ◽  
The Cost

This paper describes the design of high-performance compact aperture array antennas for radio astronomy and other applications. Three recent antenna developments for square kilometer array design study (SKADS) have been investigated and the performances are compared. In addition to the radio frequency (RF) performance, an essential requirement for the square kilometer array application is the cost per square area. Based on initial large–scale finite array studies, prototypes with different geometries have been fabricated and measured. Guidelines are derived for large–scale wide–band dual-polarized array designs in applications where low cross-polarization and a wide range of scan angles are required.

scholarly journals A Solution-processed Inorganic Emitter with High Spectral Effectiveness for Efficient Daytime Radiative Cooling in Hot Humid Climates

2021 ◽  
Author(s):  
Chongjia Lin ◽  
Yang Li ◽  
Cheng Chi ◽  
Ye Seul Kwon ◽  
Chi Yan Tso ◽  
...  
Keyword(s):  
Self Assembly ◽  
High Performance ◽  
Large Scale ◽  
Infrared Emission ◽  
Radiative Cooling ◽  
Zero Energy ◽  
Solar Reflectance ◽  
Solar Shading ◽  
Space Cooling

Abstract Daytime radiative cooling provides an eco-friendly solution to space cooling with zero energy consumption. Despite significant advances, most state-of-the-art radiative coolers show broadband infrared emission with low spectral effectiveness, which limits their cooling temperatures and climate applicabilities, especially in hot humid regions. Here we report an all-inorganic narrowband cooler comprising a solution-derived SiOxNy layer sandwiched between a reflective substrate and a self-assembly monolayer of SiO2 microspheres. It shows a high and diffusive solar reflectance (96%) and strong infrared-selective emittance (94.6%) with superior spectral effectiveness (1.44). Remarkable subambient cooling of up to 5°C was achieved under high humidity without any solar shading or convection cover at noontime in a subtropical coastal city, Hong Kong. Owing to the all-inorganic hydrophobic structure, the emitter showed outstanding resistance to ultraviolet and water in the long-term durability tests. The scalable solution-based fabrication renders this stable high-performance emitter promising for large-scale deployment in various climates.

Does 0.1 Micron = MACH 1?

1995 ◽  
Vol 380 ◽  
Author(s):  
R. Fabian Pease
Keyword(s):  
High Performance ◽  
Large Scale ◽  
State Of The Art ◽  
Commercial Use ◽  
Optical Projection ◽  
Large Scale Integration ◽  
On Chip ◽  
Scale Integration ◽  
The Cost ◽  
The Military

ABSTRACTThe drive to increasingly higher density ultra-large-scale-integration (ULSI) (of electronic circuits) is fuelled primarily by cost; on-chip interconnects are far cheaper than the less dense offchip interconnects. At the same time the escalating cost of an IC factory (‘fab’) is making headlines as it goes through $1B and a large part of this escalation is the cost of high performance lithography tools. The lithographic technology to go below 0.1μm will almost certainly be very different from an extension of today's optical projection and the cost of replacing today's technology will be enormous. A second drawback to higher density is the resistance of narrow interconnects. As a result some people have suggested that this situation is analogous to that of airliner speed which increased over a period of thirty years from about 100 mph to close to 600 mph but has not increased in the last 35 years. Still faster speed was technically possible, and hence was pursued by the military, but is uneconomical for most commercial use. Current technology might take us to 0.1μm which will probably be state of the art 10 years hence so technologies for replacing optical lithography e.g. scanned arrays of proximal probes should be researched now. Other challenges include how to achieve useful interconnect networks employing 50 nm features.

Purification of Epothilones A and B with Column Chromatography on a Sephadex LH-20

2014 ◽  
Vol 904 ◽  
pp. 164-169
Author(s):  
Ji Kun Yang ◽  
Lin Zhao ◽  
Rui Cheng Sun ◽  
Yue Mao Shen ◽  
Nai Qiang Wang ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Column Chromatography ◽  
High Performance ◽  
Large Scale ◽  
Complete Separation ◽  
Pure Ethanol ◽  
Fermentation Products ◽  
Epothilone A ◽  
Pure Methanol ◽  
The Cost

A simplified and efficient method was developed for the large-scale purification of the epothilone A and B from fermentation products ofSorangium cellulosumafter organic solvent extraction in this paper. Extractant from XAD-16 resin with tetrachloromethane containing epothilones was concentrated under vacuum, subjected to Sephadex LH-20 column chromatography, and eluted with several solvents. Fractions containing epothilones are pooled, concentrated, and applied to a second cycle of column chromatography with other solvents. Result showed that elution with acetone gave the best purity of epothilones [78.1% by high-performance liquid chromatography (HPLC) than that with pure methanol, pure ethanol, 70% (v/v) aqueous methanol or methanol-dichloromethane (1:1, v/v).] Then, when flow rate was 0.2 mL/min and sample amount (epoA) was 1 mg in second cycle, elution with methanol was resulted in complete separation between epothilone A and B, and further improved separately the purity of epothilone A and B to 90.27% and 77.34%. This simplified purification scheme avoided the loss of expensive epothilones in the common silica gel separation process and achieved the separation of epothilone A and B, significantly reduce the cost of the production without preparative liquid chromatography, or other equipment.

scholarly journals Applying a Hybrid Sequential Model to Chinese Sentence Correction

Symmetry ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1939
Author(s):  
Jun Wei Chen ◽  
Xanno K. Sigalingging ◽  
Jenq-Shiou Leu ◽  
Jun-Ichi Takada
Keyword(s):  
Neural Network ◽  
Deep Learning ◽  
Language Learning ◽  
High Performance ◽  
Large Scale ◽  
Computation Time ◽  
Semantic Error ◽  
Commercial Applications ◽  
Time Required ◽  
The Cost

In recent years, Chinese has become one of the most popular languages globally. The demand for automatic Chinese sentence correction has gradually increased. This research can be adopted to Chinese language learning to reduce the cost of learning and feedback time, and help writers check for wrong words. The traditional way to do Chinese sentence correction is to check if the word exists in the predefined dictionary. However, this kind of method cannot deal with semantic error. As deep learning becomes popular, an artificial neural network can be applied to understand the sentence’s context to correct the semantic error. However, there are still many issues that need to be discussed. For example, the accuracy and the computation time required to correct a sentence are still lacking, so maybe it is still not the time to adopt the deep learning based Chinese sentence correction system to large-scale commercial applications. Our goal is to obtain a model with better accuracy and computation time. Combining recurrent neural network and Bidirectional Encoder Representations from Transformers (BERT), a recently popular model, known for its high performance and slow inference speed, we introduce a hybrid model which can be applied to Chinese sentence correction, improving the accuracy and also the inference speed. Among the results, BERT-GRU has obtained the highest BLEU Score in all experiments. The inference speed of the transformer-based original model can be improved by 1131% in beam search decoding in the 128-word experiment, and greedy decoding can also be improved by 452%. The longer the sequence, the larger the improvement.

scholarly journals Scalable slot-die coating of high performance perovskite solar cells

2018 ◽  
Vol 2 (11) ◽  
pp. 2442-2449 ◽  
Author(s):  
James B. Whitaker ◽  
Dong Hoe Kim ◽  
Bryon W. Larson ◽  
Fei Zhang ◽  
Joseph J. Berry ◽  
...  
Keyword(s):  
Energy Production ◽  
High Performance ◽  
Large Scale ◽  
Perovskite Solar Cells ◽  
Photovoltaic Devices ◽  
Slot Die Coating ◽  
Active Layers ◽  
Slot Die ◽  
The Cost ◽  
Scale Deposition

Perovskite based photovoltaic devices hold the promise to greatly reduce the cost of solar energy production; however, this potential depends greatly on the ability to deposit perovskite active layers using large scale deposition methods such as slot-die coating without sacrificing efficiency.

scholarly journals Structure Engineering in Biomass-Derived Carbon Materials for Electrochemical Energy Storage

Research ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-27 ◽  
Author(s):  
Ruizi Li ◽  
Yanping Zhou ◽  
Wenbin Li ◽  
Jixin Zhu ◽  
Wei Huang
Keyword(s):  
Energy Storage ◽  
High Performance ◽  
Rational Design ◽  
Large Scale ◽  
Electrode Materials ◽  
Carbon Materials ◽  
Electrochemical Energy Storage ◽  
Diffusion Kinetics ◽  
Practical Application ◽  
Electrochemical Energy

Biomass-derived carbon materials (B-d-CMs) are considered as a group of very promising electrode materials for electrochemical energy storage (EES) by virtue of their naturally diverse and intricate microarchitectures, extensive and low-cost source, environmental friendliness, and feasibility to be produced in a large scale. However, the practical application of raw B-d-CMs in EES is limited by their relatively rare storage sites and low diffusion kinetics. In recent years, various strategies from structural design to material composite manipulation have been explored to overcome these problems. In this review, a controllable design of B-d-CM structures boosting their storage sites and diffusion kinetics for EES devices including SIBs, Li-S batteries, and supercapacitors is systematically summarized from the aspects of effects of pseudographic structure, hierarchical pore structure, surface functional groups, and heteroatom doping of B-d-CMs, as well as the composite structure of B-d-CMs, aiming to provide guidance for further rational design of the B-d-CMs for high-performance EES devices. Besides, the contemporary challenges and perspectives on B-d-CMs and their composites are also proposed for further practical application of B-d-CMs for EES devices.

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