Decoding the relationships between electrocaloric coefficient and phase structure in perovskite ferroelectrics towarding high performance

2020 ◽  
Author(s):  
Xiaowei Wei ◽  
Chunlin Zhao ◽  
Ting Zheng ◽  
Jiagang Wu
Keyword(s):  
Phase Structure ◽  
High Performance ◽  
Vapor Compression ◽  
Electrocaloric Effect ◽  
Environment Friendly ◽  
Polarization Change

Electrocaloric effect represents an environment-friendly cooling alternative to replace currently ubiquitous vapor-compression-based refrigeration. Previous works have shown that large electrocaloric response is associated with polarization change which peaks around phase...

Phase structure engineering of MnCo2Ox within electrospun carbon nanofibers towards high-performance lithium-ion batteries

2021 ◽  
Author(s):  
Huiying Lu ◽  
Ruifeng Qian ◽  
Lei Zhu ◽  
Tianhao Yao ◽  
Chao Li ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Carbon Nanofibers ◽  
Phase Structure ◽  
High Performance ◽  
Lithium Ion ◽  
Structure Engineering

scholarly journals Design and Simulation DFIM Driven Electrical Vehicles Based on IP Controller

2018 ◽  
Vol 17 (2) ◽  
pp. 43-50
Author(s):  
Al-Mayhedee Zubair ◽  
Mohammad Abdul Mannan ◽  
Junji Tamura
Keyword(s):  
High Performance ◽  
Speed Control ◽  
Pi Controller ◽  
Human Beings ◽  
Environment Friendly ◽  
Fundamental Goal ◽  
Electrical Vehicles ◽  
Electrical Vehicle ◽  
High Performance Application ◽  
Control Application

The environment friendly blessings of Electrical Vehicles (EV), human beings are becoming extra involved in the use of them alternatively than the usage of mechanical differentials. In electrical vehicles distinct sorts of electrical machines are used among them DFIM is used in this work. The challenging work is to design of a controller as the output of the motor has to match with vehicle input. So, far, most of the mentioned works have utilized Proportional-Integral (PI) controllers as the speed control. But, the negative aspects of PI controller are properly known, as its design depends on the specific motor parameters and the overall performance is sensitive to system disturbances. The fundamental goal of this paper is to replace the conventional PI controller by means of an IP controller which is successful of dealing with exceedingly non-linear DFIM motor for high performance application in Electrical Vehicle. The effectiveness of designed IP controller of an electrical differential for an EV system is evaluated through Matlab/Simulink software. In simulation work different road conditions for EV are considered. After the simulation the designed controller is found to be strong for the speed control application of Electrical Vehicle.

Miniature Vapor Compression Refrigeration Systems for Active Cooling of High Performance Computers

2001 ◽  
Author(s):  
Ali Heydari ◽  
Kathy Russell
Keyword(s):  
Heat Exchanger ◽  
High Performance ◽  
Capillary Tube ◽  
New Technology ◽  
Mathematical Formulation ◽  
Coefficient Of Performance ◽  
Simulation Program ◽  
Vapor Compression ◽  
Refrigeration System ◽  
System Components

Abstract A small refrigeration system for cooling of computer system components is evaluated. A thermodynamic model describing the performance of the cycle along with a computer simulation program is developed to evaluate its performance. The refrigeration system makes use of a miniature reciprocating vapor compression compressor. Due to space limitations in some high performance computer servers, a miniature refrigeration system composed of a compressor, capillary tube, a compact condenser, and a cold-plate evaporator heat exchanger are used. Mathematical multi-zone formulation for modeling thermal-hydraulic performance of heat exchanger for the condenser and evaporator are presented. The throttling device is a capillary tube and there is presented a mathematical formulation for predicting refrigerant mass flow rate through the throttling device. A physically based efficiency formulation for simulating the performance of the miniature compressor is used. An efficient iterative numerical scheme with allowance for utilization of various refrigerants is developed to solve the governing system of equations. Using the simulation program, the effects of parameters such as the choice of working refrigerant, evaporating and condensing temperatures on system components and overall efficiency of system are studied. In addition, a RAS (reliability, availability and serviceability) discussion of the proposed CPU-cooling refrigeration solution is presented. The results of analysis show that the new technology not only overcomes many shortcomings of the traditional fan-cooled systems, but also has the capacity of increasing the cooling system’s coefficient of performance.

scholarly journals Synthesis and properties of a high-performance environment-friendly micro–nano filtration reducer

RSC Advances ◽  
2020 ◽  
Vol 10 (70) ◽  
pp. 43204-43212
Author(s):  
Yanling Wang ◽  
Baoyang Jiang ◽  
Jincheng Lan ◽  
Ning Xu ◽  
Jinsheng Sun ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Graft Copolymer ◽  
High Performance ◽  
Research Study ◽  
Hydroxyethyl Cellulose ◽  
Environment Friendly ◽  
Hydrophobically Associating ◽  
Nano Filtration

In this research study, we modified hydroxyethyl cellulose to obtain hydrophobically associating hydroxyethyl cellulose, and grafted it onto the surface of nano-calcium carbonate to obtain a graft copolymer.

A Novel Way of Separation and Preparation Noncaffeine Tea Polyphenols from Green Tea Waste

2012 ◽  
Vol 550-553 ◽  
pp. 1875-1880 ◽  
Author(s):  
He Ping Tan ◽  
Huai Ping Li ◽  
Hang Song ◽  
Wen Ping Xu ◽  
Chi Guan ◽  
...  
Keyword(s):  
Green Tea ◽  
Column Chromatography ◽  
High Performance ◽  
Ethanol Solution ◽  
Tea Polyphenols ◽  
Raw Material ◽  
Environment Friendly ◽  
Tea Waste ◽  
One Step ◽  
The Stability

A simple, clean and economical way of separation and preparation noncaffeine tea polyphenols from green tea waste in one-step by Sephadex LH-20 column chromatography was developed. 20% (v/v) ethanol solution was used for removing caffeine and other components in the first stepwise elution, and tea polyphenols was eluted with 60% (v/v) ethanol solution by using reversed flow in the second stepwise elution. The yield of tea polyphenols above 11% with the purity about 98% and the content of catechins more than 91%, and the content of caffeine in tea polyphenols have not been detected by high-performance liquid chromatography. The recovery of tea polyphenols by column chromatography were about 86%, and the stability of preparative way is very good. Compared with conventional extraction and decaffeination ways, this way has more excellent advantages, such as cheaper raw material, no toxic residues, higher yield, commercially feasible and environment friendly.

scholarly journals A Review on Binderless Tungsten Carbide: Development and Application

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Jialin Sun ◽  
Jun Zhao ◽  
Zhifu Huang ◽  
Ke Yan ◽  
Xuehui Shen ◽  
...  
Keyword(s):  
Tungsten Carbide ◽  
High Performance ◽  
Current Knowledge ◽  
Electrical Contacts ◽  
Practical Significance ◽  
Sintering Behavior ◽  
Mechanical Seals ◽  
Environment Friendly ◽  
Price Instability ◽  
Processing Techniques

AbstractWC-Co alloys have enjoyed great practical significance owing to their excellent properties during the past decades. Despite the advantages, however, recently there have been concerns about the challenges associated with the use of Co, i.e. price instability, toxicity and properties degeneration, which necessitates the fabrication of binderless tungsten carbide (BTC). On the other hand, BTC or BTC composites, none of them, to date has been commercialized and produced on an industrial scale, but only used to a limited extent for specialized applications, such as mechanical seals undergoing high burthen as well as high temperature electrical contacts. There are two challenges in developing BTC: fully densifying the sintered body together with achieving a high toughness. Thus, this review applies towards comprehensively summarize the current knowledge of sintering behavior, microstructure, and mechanical properties of BTC, highlighting the densification improving strategies as well as toughening methods, so as to provide reference for those who would like to enhance the performance of BTC with better reliability advancing them to further wide applications and prepare the material in a way that is environment friendly, harmless to human health and low in production cost. This paper shows that the fabrication of highly dense and high-performance BTC is economically and technically feasible. The properties of BTC can be tailored by judiciously selecting the chemical composition coupled with taking into careful account the effects of processing techniques and parameters.

scholarly journals Microwave-assisted modifications of polysaccharides

2014 ◽  
Vol 86 (11) ◽  
pp. 1695-1706 ◽  
Author(s):  
Jacques Desbrières ◽  
Charlotte Petit ◽  
Stéphanie Reynaud
Keyword(s):  
Microwave Irradiation ◽  
High Performance ◽  
Recent Literature ◽  
Conventional Heating ◽  
Natural Polymers ◽  
Environment Friendly ◽  
Microwave Assisted ◽  
The Past ◽  
Energy Consuming

Abstract Polysaccharides are a natural and renewable feed stock for synthesizing high performance macromolecular materials. However, their structure does not allow reaching all properties required for specific applications and chemical modifications are necessary to reach such objectives. Despite the use of natural polymers, the chemistry and processes employed are not environment-friendly due to the nature of chemicals, solvents or because the conventional chemical process are energy-consuming. On the other hand, microwave assisted processes were developed in organic chemistry since the 1980s and more recently for polymer chemistry (polymer formation and modification). Within the chemistry of natural polymers, the use of microwave irradiation has been exploited in the past two decades to alleviate limitations in the synthesis of graft modified polysaccharide materials. Microwave heating is described as more homogeneous, selective and efficient as compared to conventional heating resulting in faster reactions with fewer or no side products as example. Different results reported within the recent literature will be discussed considering the role of microwave irradiation and its consequence on the reaction parameters and properties of final materials. Grafting of polysaccharides, specific modification of polysaccharides or fibers particularly for preparing smart textiles or medical products as well as reactions of polysaccharides to valuable bio-platform molecule will be discussed.

Biological Aerated Filters: An Adapted Biological Process for Wastewater from Coastal Areas

1992 ◽  
Vol 25 (12) ◽  
pp. 175-184 ◽  
Author(s):  
R. Pujol ◽  
J. P. Canler ◽  
A. Vachon ◽  
P. Vidou
Keyword(s):  
High Performance ◽  
Wastewater Treatment Plants ◽  
Coastal Areas ◽  
Organic Load ◽  
Main Concern ◽  
Environment Friendly ◽  
Load Variations ◽  
Effluent Quality ◽  
Physico Chemical ◽  
Flow Rate Control

SUMMARY compact facilities together with modular and environment-friendly appearance are arguments in favour of Biological Aerated Filters(B. A. F. ) in coastal areas where the amount of available land imposes strict limitations on technological choices. The operation of B. A. F. in combination with a physico-chemical process was studied using the data obtained from two wastewater treatment plants located in coastal areas (Barcares and Saint Palais/Mer, France). The main conclusions are the following.-Effluent quality in terms of COD, BOD5 S.S. proved satisfactory for organic load conditions higher than those applied when using conventional procedures.-Adaptation to organic load variations is not a basic problem for this type of coastal community,but hydraulic flow-rate control should be the main concern.-Restarting plant operation after a long shutdown only takes a few days.-Furthermore technical and economical optimisation required continuous monitoring, especially in the field of washing and aerating control. This type of management involves the use of reliable, high- performance control equipment.

Development of High Performance C-Rich a-SiC Semiconductors with Narrow-Optical Gap By Control of Its Phase Structure

2020 ◽  
Vol MA2020-02 (27) ◽  
pp. 1906-1906
Author(s):  
Kensuke Honda ◽  
Akari Matsumoto
Keyword(s):  
Phase Structure ◽  
High Performance ◽  
Optical Gap
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