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Introduction
Published in Shoogo Ueno, Tsukasa Shigemitsu, Bioelectromagnetism, 2022
Shoogo Ueno, Tsukasa Shigemitsu
The properties of electromagnetic waves necessary for understanding the various effects of electromagnetic fields on biological systems will be briefly presented. They describe the fundamental aspects of electric and magnetic fields as well as the electromagnetic wave. To begin, consider the case where a direct current (DC) power supply is connected to a single wire stretched in the air. The wire is being charged by the electric charge from the power source, and electric lines of force are generated from the wire to the ground. Although the electric lines of force are invisible to the eye, their existence can be confirmed by the fact that when another charged particle is placed between the wire and the ground, it can receive either an attractive or repulsive force in the direction of the electric lines of force. The space where these electric lines of force exist, that is the field where the electric force act, is called electric field. Its strength is defined by the force that acts when a unit charge is placed there. Now, if an alternating current (AC) power source is connected to the same cable instead of a DC power supply, the polarity of the cable charge reverses direction with its frequency. Therefore, the direction of the electric lines of force is also reversing with its frequency, but the pattern of distribution remains the same. In short, an electric field is a region of space over which an electric charge exerts a force on charged objects in its vicinity. The unit of the electric field strength is Newton/Coulomb (N/C), and in practical use, the unit is expressed in Volt/Meter (V/m).
Energy Basics/Foundation for Understanding
Published in Dale R. Patrick, Stephen W. Fardo, Ray E. Richardson, Brian W. Fardo, Energy Conservation Guidebook, 2020
Dale R. Patrick, Stephen W. Fardo, Ray E. Richardson, Brian W. Fardo
It is important to note that atoms are also composed of smaller or subatomic particles. These are called electrons, protons, and neutrons. An electron holds a negative electrical charge, whereas a proton possesses a positive charge. Neutrons are electrically neutral and have no charge. Electricity is based upon the flow or movement of electrons within electrical conductors.
Renewable Energy
Published in Chitrarekha Kabre, Synergistic Design of Sustainable Built Environments, 2020
Electrical energy is delivered by tiny charged particles called electrons, typically moving through a wire. Lighting is an example of electrical energy in nature. The presence of free electrons in a body represents a charge, an electric potential. These electrons tend to flow from a higher potential zone to a lower one. The unit of electric charge is the coulomb (C). The rate of electricity flow (current) is the ampere (amp, A): A=C/s conversely C=A×s
Experimental study on rotary triboelectric separation of low-rank coal macerals with surface modification
Published in Particulate Science and Technology, 2022
Xuebin Zhang, Youjun Tao, Dongping Tao, Fangyuan Ma, Yushuai Xian
He, Sun, Zhao et al. (2018) proposed that the surface work function determines the charging properties of macerals. A material with a relatively higher work function is negatively charged while the material with a relatively lower surface work function develops positive charge. Both vitrinite and inertinite have lower surface work functions. According to electric field force formula F = qE (q: electric charge; E: electric field strength), the larger the charge–mass ratio of particles, the higher the electric field force they receive in the electric field, and the greater the displacement they gain in the horizontal direction. It is more conducive to the triboelectric separation effect. Therefore, the high charge–mass ratio of macerals treated by kerosene and diesel indicates that kerosene and diesel develop better surface modification effects.
Principles of preparing broad-wave reflective films supported by nanofiber networks
Published in Liquid Crystals, 2022
Miaomiao Jia, Zongcheng Miao, Dong Wang
In the electrospinning process, the jetting device is filled with a charge of polymer solution or molten liquid. Under the action of an applied electric field, the polymeric liquid held at the nozzle by surface tension droplet, induced by the electric field, collects an electric charge on the surface and is subjected to an electric field force in the opposite direction of the surface tension. When the electric field gradually increases, the droplet at the nozzle is elongated from a spherical shape to a cone shape, forming a so-called ‘Taylor cone’. The so-called ‘Taylor cone’ (Taylor cone). And when the electric field strength increases to ~ a critical value, the electric field force will overcome the liquid surface tension and is ejected from the ‘Taylor cone’. The jet is shocked by the high electric field, the jet is oscillated and unstable, resulting in a very high frequency of irregular spiral motion. In a high-speed oscillation; the plane stream is rapidly thinned and the solvent evaporates quickly, resulting in a jet stream of nano-sized fibres in diameter, which are scattered randomly on the collection device, forming a nonwoven fabric, or with a moving or rotating receiving device. Or a moving or rotating receiving device to obtain nanofiber oriented in a specific direction. The nanofiber mats are oriented in a certain direction with a moving or rotating receiving device [30–35].
Analysis of energy and momentum transport for Casson nanofluid in a microchannel with radiation and chemical reaction effects
Published in Waves in Random and Complex Media, 2022
Sneha Gajbhiye, Arundhati Warke, Katta Ramesh
When , the propulsion of Casson liquid is feasible, we get Using Equation (11) in Equation (12) the Casson liquid viscosity expressed as The generalized Darcy's resistance of the porous media is defined as The generalized Ohm's law is represented by where denote electron frequency, is the magnetic field, e denotes electric charge, defined wall stress induced by the electric field, represents number density of electron, E is the electric field and is electronic pressure.