The evolution of surfaces and mechanisms of contact electrification between metals and polymers

2022 ◽  
Author(s):  
Linfeng Wang ◽  
Yi Dong ◽  
Minhao Hu ◽  
Jing Tao ◽  
Jin Li ◽  
...  
Keyword(s):  
Functional Groups ◽  
Metal Surfaces ◽  
Energy Harvest ◽  
Common Phenomenon ◽  
Material Transfer ◽  
Design And Optimization ◽  
Contact Electrification ◽  
Contact Frequency ◽  
Self Powered ◽  
The Relationship

Abstract Contact electrification (CE) is a pretty common phenomenon, but still is poorly understood. The long-standing controversy over the mechanisms of CE related to polymers is particularly intense due to their complexity. In this paper, the CE between metals and polymers is systematically studied, which shows the evolution of surfaces accompanied by variations of CE outputs. The variations of CE charge are closely related to the creep and deformation of the polymer and metal surfaces. Then the relationship between CE and polymer structures is put forward, which is essentially determined by the electronegativity of elements and the functional groups in the polymers. The effects of load and contact frequency on the CE process and outputs are also investigated, indicating the increase of CE charge with load and frequency. Material transfer from polymer to metal is observed during CE while electrons transfer from metal to polymer, both of which are believed to have an influence on each other. The findings advance our understanding on the mechanism of CE between metal and polymers, and provides insights into the performance of CE-based application in various conditions, which sheds light on the design and optimization of CE-based energy harvest and self-powered sensing devices.

scholarly journals Are rate and selectivity correlated in iridium-catalysed hydrogen isotope exchange reactions?

2021 ◽  
Author(s):  
Daria S. Timofeeva ◽  
David M Lindsay ◽  
W. J. Kerr ◽  
David James Nelson
Keyword(s):  
Functional Groups ◽  
Hydrogen Isotope ◽  
Isotope Exchange ◽  
Reaction Rate ◽  
Exchange Reactions ◽  
Reaction Selectivity ◽  
Hydrogen Isotope Exchange ◽  
The Relationship

Herein we examine the relationship between reaction rate and reaction selectivity in iridium-catalysed hydrogen isotope exchange (HIE) reactions directed by Lewis basic functional groups. We have recently develped a directing...

scholarly journals Energy Efficient SWIPT Based Mobile Edge Computing Framework for WSN-Assisted IoT

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4798
Author(s):  
Fangni Chen ◽  
Anding Wang ◽  
Yu Zhang ◽  
Zhengwei Ni ◽  
Jingyu Hua
Keyword(s):  
Energy Consumption ◽  
Transmission Rate ◽  
Edge Computing ◽  
Energy Harvest ◽  
Total System ◽  
Mobile Edge Computing ◽  
Weight Factor ◽  
Iot Devices ◽  
System Variables ◽  
The Relationship

With the increasing deployment of IoT devices and applications, a large number of devices that can sense and monitor the environment in IoT network are needed. This trend also brings great challenges, such as data explosion and energy insufficiency. This paper proposes a system that integrates mobile edge computing (MEC) technology and simultaneous wireless information and power transfer (SWIPT) technology to improve the service supply capability of WSN-assisted IoT applications. A novel optimization problem is formulated to minimize the total system energy consumption under the constraints of data transmission rate and transmitting power requirements by jointly considering power allocation, CPU frequency, offloading weight factor and energy harvest weight factor. Since the problem is non-convex, we propose a novel alternate group iteration optimization (AGIO) algorithm, which decomposes the original problem into three subproblems, and alternately optimizes each subproblem using the group interior point iterative algorithm. Numerical simulations validate that the energy consumption of our proposed design is much lower than the two benchmark algorithms. The relationship between system variables and energy consumption of the system is also discussed.

scholarly journals Kinetics and optimization on discoloration of dyeing wastewater by schorl-catalyzed fenton-like reaction

2014 ◽  
Vol 79 (3) ◽  
pp. 361-377 ◽  
Author(s):  
Huan-Yan Xu ◽  
Wei-Chao Liu ◽  
Shu-Yan Qi ◽  
Yan Li ◽  
Yuan Zhao ◽  
...  
Keyword(s):  
Response Surface ◽  
Reaction Rate Constant ◽  
Second Order ◽  
Order Kinetic ◽  
Reaction Conditions ◽  
Design And Optimization ◽  
Order Kinetic Model ◽  
Kinetic Investigations ◽  
The Relationship ◽  
Experimental Design And Optimization

Kinetics and optimization on the discoloration of an active commercial dye, Argazol Blue BFBR (ABB) by heterogeneous Fenton-like reaction catalyzed by natural schorl were investigated in this study. Kinetic investigations revealed that the first-order kinetic model was more favorable to describe the discoloration of ABB at different reaction conditions than the second-order and Behnajady-Modirshahla-Ghanbery models. The relationship between the reaction rate constant k and reaction temperature T followed the Arrhenius equation, with the apparent activation energy Ea of 51.31kJ?mol-1. The central composite design under the response surface methodology was employed for the experimental design and optimization of the ABB discoloration process. The significance of a second order polynomial model for predicting the optimal values of ABB discoloration was evaluated by the analysis of variance and 3D response surface plots for the interactions between two variables were constructed. Then, the optimum conditions were determined.

Application of Steel Spring on the ZnO Nanorods Self-Powered Triboelectric Nanogenerator for Efficient Energy Harvest in Transformers

2021 ◽  
Author(s):  
Agnes Nascimento Simoes ◽  
Danilo Jose Carvalho ◽  
Eugenio de Souza Morita ◽  
Helen Veloso Vendrameto ◽  
Li Fu ◽  
...  
Keyword(s):  
Zno Nanorods ◽  
Energy Harvest ◽  
Triboelectric Nanogenerator ◽  
Steel Spring ◽  
Efficient Energy ◽  
Self Powered

Experimental Study of Thermoelectric Generators

2014 ◽  
Vol 663 ◽  
pp. 299-303 ◽  
Author(s):  
Ubaidillah ◽  
Suyitno ◽  
Imam Ali ◽  
Eko Prasetya Budiana ◽  
Wibawa Endra Juwana
Keyword(s):  
Output Voltage ◽  
Thermoelectric Generator ◽  
Electrical Energy ◽  
Thermoelectric Generators ◽  
Data Logger ◽  
Computer Data ◽  
Standard Module ◽  
Self Powered ◽  
Resistive Loads ◽  
The Relationship

Thermoelectric generator is solid-state device which convert temperature difference, ∆T into electrical energy based on Seebeck effect phenomenon. The device has been widely used in self-powered system applications. This paper focuses on presentation of methodology for characterizing thermoelectric generators. The measurement of its behavior is performed by varying load resistances. A standard module of thermoelectric generator (TEC1-12710) is used in examination and an instrument setup consists of controllable heat source, controllable cooler, personal computer, data logger MCC DAQ USB-1208LS equipped with two sets of K-type thermocouples. The experiment is performed by measuring output voltage and output current in 4 values of temperature gradient by applying 10 values of resistive loads connected to the thermoelectric output wires. The common parameters studied in this research are output voltage, current and power. Generally, the relationship between parameters agrees with the basic theory and the procedure can be adopted for characterizing other type of thermoelectric generator.

Relative deprivation and phubbing: Fear of missing out as a mediator

2021 ◽  
Vol 49 (7) ◽  
pp. 1-9
Author(s):  
Yang Wu ◽  
Xiaoying Yang
Keyword(s):  
College Students ◽  
Relative Deprivation ◽  
Psychosocial Factor ◽  
Social Contexts ◽  
Common Phenomenon ◽  
Fear Of Missing Out ◽  
The Individual ◽  
The Relationship

Phubbing, defined as paying attention to one's smartphone instead of interacting with other people in social contexts, has become a common phenomenon. However, the determinants of this behavior remain unclear. Therefore, we explored whether fear of missing out mediates the relationship between relative deprivation and phubbing. A sample of 858 college students completed measures to assess relative deprivation, fear of missing out, and phubbing. The results show that relative deprivation was positively correlated with phubbing. Further, fear of missing out fully mediated the relationship between relative deprivation and phubbing, which indicates that college students who perceived more relative deprivation tended to be more prone to experiencing fear of missing out, and thus more vulnerable to phubbing. Our findings extend understanding of the antecedents of phubbing from the individual microlevel to the psychosocial factor macrolevel.

The Phenomenon of Corruption As a Type of Anti-Competitive Conduct Model

2021 ◽  
pp. 62-72
Author(s):  
D. Yu. Fedotov
Keyword(s):  
Economic Factors ◽  
Human Society ◽  
Common Phenomenon ◽  
Market Participants ◽  
Econometric Methods ◽  
The World ◽  
Competitive Model ◽  
Level Of Economic Development ◽  
Human Desire ◽  
The Relationship

The article examines the origin of corruption as a social and economic phenomenon that is persistent in society. The purpose of the study is to identify the causes of corruption and the economic factors that influence it. It is revealed that corruption existed in all epochs of human society and in all countries of the world, regardless of their level of economic development and political structure. It is concluded that corruption, as a common phenomenon, comes from the usual human desire to obtain privileges in society, but with the use of illegal methods. It is revealed that in addition to cases of corruption, the desire to obtain a privileged position is also observed in cases where economic entities use an anti-competitive model of conduct in relations with other market participants. This led to a conclusion about the mutually overwhelming influence of competition and corruption on each other — the more competition is developed in a country, the lower the level of corruption in it. In this paper, using econometric methods, a correlation analysis of the relationship between competition and corruption in 140 countries of the world is carried out. The results obtained suggest that increasing the level of competition in the economy will reduce the scale of corruption in the country.

scholarly journals Norbornadiene-functionalized triazatriangulenium and trioxatriangulenium platforms

2019 ◽  
Vol 15 ◽  
pp. 1815-1821 ◽  
Author(s):  
Roland Löw ◽  
Talina Rusch ◽  
Tobias Moje ◽  
Fynn Röhricht ◽  
Olaf M Magnussen ◽  
...  
Keyword(s):  
Functional Groups ◽  
Metal Surfaces ◽  
Flat Surfaces ◽  
Change Mechanism ◽  
Central Carbon ◽  
Atomically Flat

Triazatriangulenium (TATA) and trioxatriangulenium (TOTA) ions are particularly suited systems to mount functional molecules onto atomically flat surfaces such as Au(111). The TATA and TOTA units serve as platforms that absorb onto the surface and form ordered monolayers, while the functional groups are protruding upright and freestanding from the central carbon atoms. Azobenzene derivatized TATA’s are known to exhibit extremely fast cis→trans isomerization on metal surfaces, via a peculiar non-adiabatic singlet→triplet→singlet mechanism. We now prepared norbornadienes (NBD) and quadricyclanes (QC) attached to TATA and TOTA platforms which can be used to check if these accelerated rates and the spin change mechanism also apply to [2 + 2] cycloreversions (QC→NBD).

Racial Discrimination and TESOL

2021 ◽  
pp. 712-726
Author(s):  
Ismael Louber
Keyword(s):  
Saudi Arabia ◽  
Cultural Identity ◽  
Racial Discrimination ◽  
Small Scale ◽  
Common Phenomenon ◽  
Kingdom Of Saudi Arabia ◽  
Racial Identities ◽  
Professional Environment ◽  
Ethnic And Cultural Identity ◽  
The Relationship

While the field of TESOL/TEFL claims to be inclusive given that it is composed of a myriad of sociocultural backgrounds and environments, racial discrimination is a common phenomenon, especially in the Kingdom of Saudi Arabia. Nonetheless, this issue has not been given enough attention by researchers, in that particular region at least. This article reports the findings of a small-scale qualitative study conducted in the Kingdom of Saudi Arabia drawing upon the experiences of six non-Saudi male English as a Foreign Language (EFL) lecturers. Open-ended questionnaires and interviews were used to collect data to explore the relationship between teachers' construction of their ethnic and racial identities and issues of discrimination within their professional environment. The study explored the participants' construction of their ethnic and cultural identity and its possible relation to discriminatory practices in their professional environment. The research showed how certain discriminatory practices affected how the participants projected their ethnic and cultural identity in their professional context.

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