scholarly journals Carbonized wood with ordered channels decorated by NiCo2O4 for lightweight and high-performance microwave absorber

2021 ◽  
Vol 11 (1) ◽  
pp. 105-119
Author(s):  
Guangyu Qin ◽  
Xiaoxiao Huang ◽  
Xu Yan ◽  
Yunfei He ◽  
Yuhao Liu ◽  
...  
Keyword(s):  
High Performance ◽  
Low Cost ◽  
Interfacial Polarization ◽  
Growth Direction ◽  
Channel Structure ◽  
Light Weight ◽  
Multiple Reflections ◽  
Element Analysis ◽  
Environmental Friendliness ◽  
Carbonized Wood

AbstractWood-derived carbon has a 3D porous framework composed of through channels along the growth direction, which is a suitable matrix for preparing electromagnetic wave (EMW) absorbing materials with low cost, light weight, and environmental friendliness. Herein, the carbonized wood decorated by short cone-like NiCo2O4 (NiCo2O4@CW) with highly ordered straight-channel architecture was successfully manufactured through a facile calcination procedure. The horizontal arrangement of the through channels of NiCo2O4@CW (H-NiCo2O4@CW) exhibits a strong reflection loss value of -64.0 dB at 10.72 GHz with a thickness of 3.62 mm and a low filling ratio of 26 wt% (with the density of 0.98 g·cm-3), and the effective absorption bandwidth (EAB) is 8.08 GHz (9.92–18.0 GHz) at the thickness of 3.2 mm. The excellent microwave absorption (MA) property was ascribed to the ordered-channel structure with abundant interfaces and defects from NiCo2O4@CW, which could promote the interfacial polarization and dipole polarization. What is more, this advantageous structure increased the multiple reflections and scattering. Finite element analysis (FEA) simulation is carried out to detect the interaction between the prepared material and EMW when the ordered channels are arranged in different directions. This research provides a low-cost, sustainable, and environmentally friendly strategy for using carbonized wood to fabricate microwave absorbers with strong attenuation capabilities and light weight.

Fused Ambipolar Aza-isoindigos with NIR absorption

2021 ◽  
Author(s):  
Liping Yao ◽  
Danlei Zhu ◽  
Hailiang Liao ◽  
Sheik Haseena ◽  
Mahesh kumar Ravva ◽  
...  
Keyword(s):  
Organic Semiconductors ◽  
High Performance ◽  
Low Cost ◽  
Light Weight ◽  
The Past ◽  
Pi Conjugated ◽  
Nir Absorption ◽  
Conjugated Organic Semiconductors

Due to their advantages of low-cost, light-weight, and mechanical flexibility, much attention has been focused on pi-conjugated organic semiconductors. In the past decade, although many materials with high performance has...

scholarly journals Recent Progress on Catalysts for the Positive Electrode of Aprotic Lithium-Oxygen Batteries †

Inorganics ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 69 ◽  
Author(s):  
Yichao Cai ◽  
Yunpeng Hou ◽  
Yong Lu ◽  
Jun Chen
Keyword(s):  
High Performance ◽  
Noble Metals ◽  
Catalytic Mechanism ◽  
Low Cost ◽  
Rate Capability ◽  
Positive Electrode ◽  
Safety Hazards ◽  
Environmental Friendliness ◽  
Potential Safety ◽  
Lithium Oxygen Batteries

Rechargeable aprotic lithium-oxygen (Li-O2) batteries have attracted significant interest in recent years owing to their ultrahigh theoretical capacity, low cost, and environmental friendliness. However, the further development of Li-O2 batteries is hindered by some ineluctable issues, such as severe parasitic reactions, low energy efficiency, poor rate capability, short cycling life and potential safety hazards, which mainly stem from the high charging overpotential in the positive electrode side. Thus, it is of great significance to develop high-performance catalysts for the positive electrode in order to address these issues and to boost the commercialization of Li-O2 batteries. In this review, three main categories of catalyst for the positive electrode of Li-O2 batteries, including carbon materials, noble metals and their oxides, and transition metals and their oxides, are systematically summarized and discussed. We not only focus on the electrochemical performance of batteries, but also pay more attention to understanding the catalytic mechanism of these catalysts for the positive electrode. In closing, opportunities for the design of better catalysts for the positive electrode of high-performance Li-O2 batteries are discussed.

Mechanical and Optimization Analyses for Novel Wound Composite Axial Impeller

2009 ◽  
Author(s):  
Jifeng Wang ◽  
Qubo Li ◽  
Norbert Mu¨ller
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Speed ◽  
High Performance ◽  
Low Cost ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Loading Conditions ◽  
Element Analysis ◽  
Wound Composite

A mechanical and optimal analyses procedure is developed to assess the stresses and deformations of Novel Wound Composite Axial-Impeller under loading conditions particular to centrifuge. This procedure is based on an analytical method and Finite Element Analysis (FEA, commercial software ANSYS) results. A low-cost, light-weight, high-performance, composite turbomachinery impeller from differently designed patterns will be evaluated. Such impellers can economically enable refrigeration plants using water as a refrigerant (R718). To create different complex patterns of impellers, MATLAB is used for creating the geometry of impellers, and CAD software UG is used to build three-dimensional impeller models. Available loading conditions are: radial body force due to high speed rotation about the cylindrical axis and fluid forces on each blade. Two-dimensional plane stress and three-dimensional stress finite element analysis are carried out using ANSYS to validate these analytical mechanical equations. The von Mises stress is investigated, and maximum stress and Tsai-Wu failure criteria are applied for composite material failure, and they generally show good agreement.

Recent progress in zinc-based redox flow batteries: a review

2021 ◽  
Author(s):  
Guixiang Wang ◽  
Haitao Zou ◽  
Xiaobo Zhu ◽  
Mei Ding ◽  
Chuankun Jia
Keyword(s):  
High Performance ◽  
Large Scale ◽  
Electrode Materials ◽  
Low Cost ◽  
Ion Selectivity ◽  
Commercial Application ◽  
Environmental Friendliness ◽  
Membrane Materials ◽  
Redox Flow Batteries ◽  
Flow Batteries

Abstract Zinc-based redox flow batteries (ZRFBs) have been considered as ones of the most promising large-scale energy storage technologies owing to their low cost, high safety, and environmental friendliness. However, their commercial application is still hindered by a few key problems. First, the hydrogen evolution and zinc dendrite formation cause poor cycling life, of which needs to ameliorated or overcome by finding suitable anolytes. Second, the stability and energy density of catholytes are unsatisfactory due to oxidation, corrosion, and low electrolyte concentration. Meanwhile, highly catalytic electrode materials remain to be explored and the ion selectivity and cost efficiency of membrane materials demands further improvement. In this review, we summarize different types of ZRFBs according to their electrolyte environments including ZRFBs using neutral, acidic, and alkaline electrolytes, then highlight the advances of key materials including electrode and membrane materials for ZRFBs, and finally discuss the challenges and perspectives for the future development of high-performance ZRFBs.

Fabrication of practical catalytic electrodes using insulating and eco-friendly substrates for overall water splitting

2020 ◽  
Vol 13 (1) ◽  
pp. 102-110 ◽  
Author(s):  
Weiju Hao ◽  
Renbing Wu ◽  
Hao Huang ◽  
Xin Ou ◽  
Lincai Wang ◽  
...  
Keyword(s):  
Water Splitting ◽  
High Performance ◽  
Low Cost ◽  
Light Weight ◽  
Overall Water Splitting ◽  
Insulating Substrates

A family of catalytic electrodes fabricated by insulating substrates of paper, cloth and sponge which bring dramatic advantages of high performance, low cost, light weight, eco-friendliness, flexibility, and simple fabrication, were developed.

Stability analysis in wound composite material axial impeller

2011 ◽  
Vol 226 (5) ◽  
pp. 1162-1172 ◽  
Author(s):  
J Wang ◽  
J Piechna ◽  
J A O Yume ◽  
N Müller
Keyword(s):  
Composite Material ◽  
Stability Analysis ◽  
Dynamic Characteristics ◽  
Composite Laminates ◽  
High Performance ◽  
Low Cost ◽  
Modal Shape ◽  
Element Analysis ◽  
Rotating Speed ◽  
Wound Composite

A stability analysis is developed to assess the stresses and dynamic characteristics of the wound composite material axial impeller under centrifugal force loading conditions. This procedure is based on finite element analysis (commercial software ABAQUS) results. A low-cost, light-weight, high-performance composite turbomachinery impeller with a uniquely designed blade patterns is evaluated. Understanding the stress–strain behaviour of fibre-reinforced composite laminates as it relates to ultimate failure and the ability to predict ultimate strength is critical in the design of safe and lightweight impellers. To determine failures, the maximum stress failure criterion is used. In order to avoid operating at resonance, which can make impellers suffer a significant reduction in the design life, the designer must calculate the natural frequency and modal shape of the impeller to analyse the dynamic characteristics. The results show that using composite Kevlar fibre/epoxy matrix enables the impeller to run at a rotating speed 2228 rad/s and withstand the stresses, no critical speed will be matched during start-up and shut-down, and that mass imbalances of the impeller shall not pose a critical problem.

Stiffness Analysis of a Simplified Ankle-Foot Orthosis

2020 ◽  
Author(s):  
Ethan Swierski ◽  
Molly Burke ◽  
Maria Arenas ◽  
Jessica Bernat ◽  
James Manzer ◽  
...  
Keyword(s):  
Design Process ◽  
Laser Cutting ◽  
High Performance ◽  
Low Cost ◽  
Walking Ability ◽  
Thermoplastic Resin ◽  
Element Analysis ◽  
Ankle Foot Orthosis ◽  
The Impact ◽  
Foot Orthosis

Abstract Due to the impact gait impairments have on afflicted individuals’ lives, there are many efforts to find effective remedies. One example is drop foot, a condition in which the dorsiflexion in the leg falters, and the forefront of the foot drags during walking. One of these is the use of an Ankle Foot Orthosis (AFO), a device worn on the lower extremity of the leg to improve walking ability. Although these orthoses have been improved over time to address a user’s physical needs, material and financial restrictions are still an obstacle. To find the lowest cost AFO design of high performance, a study was conducted to investigate the applications of a simplified design process for an AFO. The design process is a fast, low cost, easy technique of laser cutting thermoplastic resin and bending a drawing into a 3-dimensional AFO. Finding the best AFO possible using this design process was easy, involving making a 2-dimensional CAD model for laser cutting, performing Finite Element Analysis (FEA) simulations and comparing a variety of designs, materials, and configurations for their ability to improve a user’s gait kinematics while also meeting optimal cost and comfort needs.

scholarly journals A Novel Magnet-Axis-Shifted Hybrid Permanent Magnet Machine for Electric Vehicle Applications

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 641 ◽  
Author(s):  
Ya Li ◽  
Hui Yang ◽  
Heyun Lin ◽  
Shuhua Fang ◽  
Weijia Wang
Keyword(s):  
Permanent Magnet ◽  
High Performance ◽  
Low Cost ◽  
Element Analysis ◽  
Interior Permanent Magnet ◽  
Rotor Pole ◽  
Ipm Machine ◽  
Electromagnetic Characteristics ◽  
The Difference ◽  
Magnet Axis

This paper proposes a novel magnet-axis-shifted hybrid permanent magnet (MAS-HPM) machine, which features an asymmetrical magnet arrangement, i.e., low-cost ferrite and high-performance NdFeB magnets, are placed in the two sides of a “▽”-shaped rotor pole. The proposed magnet-axis-shift (MAS) effect can effectively reduce the difference between the optimum current angles for maximizing permanent magnet (PM) and reluctance torques, and hence the torque capability of the machine can be further improved. The topology and operating principle of the proposed MAS-HPM machine are introduced and are compared with the BMW i3 interior permanent magnet (IPM) machine as a benchmark. The electromagnetic characteristics of the two machines are investigated and compared by finite element analysis (FEA), which confirms the effectiveness of the proposed MAS design concept for torque improvement.

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