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Absorption/Emission Spectroscopy and Spectral Lines 5
Published in Caio Lima Firme, Quantum Mechanics, 2022
Lorentz had been working on electrodynamics since 1892 (according to Lorentz, the oscillations of the charged particles in the atom were the source of light) and right after the discovery of the Zeeman effect, Lorentz gave its classical theoretical interpretation. He explained that atoms contain charged particles called ‘ions’ (later called electrons) harmonically bound to a center. The frequencies of their vibrations correspond to the frequencies of the spectral lines of the analyzed substance. When a magnetic field is applied, the vibrating particles will experience a Lorentz force in addition to the harmonic force. The Lorentz force F describes the force acting on a particle of charge q moving with a velocity v in an electric field E and a magnetic field B experiences a force: F=qE+qv×B
Magnetic Nanosensors
Published in Vinod Kumar Khanna, Nanosensors, 2021
All conductors exhibit a weak MR effect, known as ordinary magnetoresistance (OMR). One such effect is the Hall effect: the generation of a voltage in a current-carrying conductor placed in a magnetic field; the voltage produced is perpendicular to both the electric current and magnetic field. Its origin lies in the Lorentz force. What is the Lorentz force? The Lorentz force is the force acting on an electrically charged particle, moving through a magnetic plus an electric field. It has two vector components, one proportional to the magnetic field and the other proportional to the electric field, to be added vectorially to obtain the total force. The strength of the magnetic component is proportional to the charge q of the particle, the speed v of the particle, the intensity B of the magnetic induction, and the sine of the angle between the vectors v and B. The direction of the magnetic component is decided by the right-hand rule: put the right hand along v with fingers pointing in the direction of v and the open palm toward the vector B. Then stretching the thumb of right hand, the Lorentz force acts along it, pointing from your wrist to the tip of your thumb. The electric component of the Lorentz force = q·E (charge of the particle multiplied by the electric field).
Modeling of Thermal Radiation and Magnetic Effects on Cu–Water Nanofluid Flow Embedded in Porous Medium Nearby a Stagnation Point Past a Stretching/Shrinking Plate with Suction/Blowing and Heat Source/Sink Using Keller-Box Method
Published in Mangey Ram, Mathematics in Engineering Sciences, 2019
Behaviors of velocity field f′(η) and temperature field θ(η) for distinct values of the magnetic parameter M are mentioned in Figures 6.7 and 6.8, respectively, besides the constant value of the remaining specified parameters. Figures 6.7 and 6.8 reveal that due to an enlargement in magnetic parameter M, fluid flow and temperature develop subjected to stretching/shrinking surface, until a reverse can be seen in temperature when η>0.5. Physically, an enhancement in the magnetic parameter tends to accelerate the Lorentz force. This type of force leads the resistive development to the fluid motion in the boundary layer and in turn creates more heat, resulting in increment of thermal boundary layer.
Direct numerical simulation study on the mechanisms of the magnetic field influencing the turbulence in compressible magnetohydrodynamic flow
Published in Journal of Turbulence, 2020
C. H. Xu, Y. H. Fan, S. Z. Wang, Z. X. Gao, C. W. Jiang, C. H. Lee
Equation (25) indicates that when the velocity is perpendicular to the magnetic field, the latter term in the right side of the equation is 0, thus the direction of the Lorentz force is opposite to that of the velocity. Meanwhile, when the velocity is parallel to the magnetic field, the Lorentz force is 0. Therefore, the Lorentz force suppresses the velocities in the directions perpendicular to the magnetic field, while has no influence on the velocity parallel to the magnetic field. Moreover, the strong transporting characteristic of turbulence always tends to change the anisotropic turbulence into isotropic turbulence, thus the v velocity which is parallel to the magnetic field also decreases, but still larger than the velocities in other two directions.
A novel perception toward welding of stainless steel by activated TIG welding: a review
Published in Materials and Manufacturing Processes, 2021
Dipali Pandya, Amarish Badgujar, Nilesh Ghetiya
Lorentz force takes place due to electric and magnetic force at a point due to electromagnetic fields. This acts on the welded region at the tip of the arc.[85] In arc movement of TIG welding, the current asymmetry results in an electromagnetic force acting in the forward direction of the welding pool.[86] At high arc speeds the value of electromagnetic force, which acts toward the canter of the weld pool and presses it down as shown in figure 6 (a). The Lorentz force () is governed by equation (2).