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Light Propagation in Anisotropic Crystals
Published in Shekhar Guha, Leonel P. Gonzalez, Laser Beam Propagation in Nonlinear Optical Media, 2017
Shekhar Guha, Leonel P. Gonzalez
Light propagates in vacuum with a constant speed c, which is given by (ε0μ0)−1/2, with ε0, the vacuum permittivity, equal to 8.85 × 10−12CV−1m−1 and μ0, the vacuum permeability, equal to 4π × 10−7Vs2C−1m−1. In material media, the speed of light (υ) depends on the properties of the medium, with υ equal to c/n, where n, the refractive index of the medium, depends on the properties of the medium. Gases, liquids, most glasses and some crystalline solids are optically isotropic, and in these media the value of n is independent of the propagation direction of light. However, many other optically transparent solids are optically anisotropic because of their anisotropic crystalline structure, and for light propagation in them, the value of n is not the same for all directions of propagation. Moreover, the allowed directions of oscillation of the electric and the magnetic fields in anisotropic media also depend on the propagation direction.
Addition of Carbon Nanofibers to Cement Pastes for Electromagnetic Interference Shielding in Construction Applications
Published in Antonella D’Alessandro, Annibale Luigi Materazzi, Filippo Ubertini, Nanotechnology in Cement-Based Construction, 2020
E. Zornoza, O. Galao, F. J. Baeza, P. Garcés
Vacuum magnetic permeability and vacuum permittivity are related according to ε0 × μ0 = 1/c2, where c is the speed of light in vacuum. Therefore, from Eq. 15.2, and taking into account that conductivity is almost zero for insulating materials, the impedance of air, which is the media used in this work, can be calculated as 377 Ω.
Torsional vibration of a flexoelectric nanotube with micro-inertia effect
Published in Mechanics of Advanced Materials and Structures, 2023
O. Hrytsyna, J. Sladek, V. Sladek, Q. Deng, M. Hrytsyna
The electric enthalpy density H is given by [88]: where is the vacuum permittivity constant (). Then, the electric enthalpy density function can be summarized as: where
Tension effect on the absorbance of a graphene layer
Published in Journal of Modern Optics, 2018
G. Khalandi, S. Roshan Entezar, A. Namdar
where and c are the vacuum permittivity and the speed of light in vacuum. and are the incident and the refracted angles respectively [11], which satisfy Snell’s law ().
Electrostatic devices related to pneumatic conveying of powders. A short literature review
Published in Particulate Science and Technology, 2021
Adoum Traoré Ndama, Elysée Obame Ndong, Hans Essone Obame, Eloi Jean Jacques Blampain
The absolute permittivity ε is the product of the relative permittivity εR and the vacuum permittivity ε0 with ε0 = 8.85 × 10−12 F/m.