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Motor Power Losses
Published in Wei Tong, Mechanical Design and Manufacturing of Electric Motors, 2022
Maxwell’s equations, which perfectly describe classical electromagnetic phenomena, consist of four equations: Faraday’s law of induction, Ampère–Maxwell’s law, and Gauss’s laws for describing electric and magnetic fields, that is,
Introduction
Published in Shoogo Ueno, Tsukasa Shigemitsu, Bioelectromagnetism, 2022
Shoogo Ueno, Tsukasa Shigemitsu
Electromagnetic waves exist on earth. James Clerk Maxwell proposed theoretically the mathematical description of an electromagnetic wave in 1865. He considered that the components of the electromagnetic wave are electric and magnetic fields, independently. After the discovery of the electromagnetic theory by Maxwell and its formulation by Oliver Heaviside, the existence of the electromagnetic wave was discovered experimentally by Heinrich Rudolf Hertz in 1888. Maxwell equations are a set of four equations which describe an electromagnetic wave: Gauss’s law, Gauss’s law for magnetism, Faraday’s law and Ampère’s law. In 1897, using electromagnetic waves, Guglielmo Marconi was able to send radio transmission signals to a tugboat at a distance over 18 miles (29 km) from the Bristol Channel, England. In 1899, Marconi sent the first international wireless message from Dover, England, to Wimereux, France. Within 4 years, he sent a wireless message across the Atlantic Ocean. These historical events opened a new era for the use of electromagnetic waves.
Historical Perspective
Published in Lynne D. Green, Fiber Optic COMMUNICATIONS, 2019
Maxwell’s equations, presented by James Clerk Maxwell [1831–1879], unified the electric and magnetic field concepts of his day. Hertz observed radio waves generated by electric currents in his laboratory. Guglielmo Marconi [1874–1937] made the first demonstration of radio transmission. These led to the development of wireless telegraphy, and later radio communications. Today, free space transmission is used for many transmission systems, such as cellular radio, TV, microwave, and satellite communications.
Design and fabrication of a fabric for electromagnetic filtering application (experimental and modeling analysis)
Published in The Journal of The Textile Institute, 2018
Mir Saeid Hesarian, Saeed Shaikhzadeh Najar, Reza Sarraf Shirazi
Maxwell’s equations relate the electric and magnetic fields to each other and to the motions of electric charges. The first Maxwell’s equation (Equation (1)), shows the electric field can be made by a variable magnetic field. Equation (2) explains dependency of the magnetic field to the electrical flow and variable electrical field. According to Equation (3) the electrical charge is a source for the electrical field and the Equation (4) describes magnetic field is made by magnetic dipole.
Application of machine learning-based approach in food drying: opportunities and challenges
Published in Drying Technology, 2022
Md. Imran H. Khan, Shyam S. Sablani, M. U. H. Joardder, M. A. Karim
Microwave based drying has proved itself as an emerging technology to drastically reduce the drying time (up to 80% of drying time).[127] However, continuous application of microwave energy deteriorates the product’s quality due to the uneven heating (creation of hot spots and cold spots).[128] To overcome such problems, microwave energy can be used in a pulsed or intermittent manner with convective hot air drying that is defended as intermittent microwave convective drying (IMCD). IMCD has been proven to improve product quality and energy efficiency by allowing redistribution of temperature and moisture within the product during tempering (MW off times) period.[129,130] Development of ML-based IMCD model is challenging as the formulation of microwave heating is a complex process. Usually, Lambert’s law and Maxwell’s equation are a well-known approach for mathematical modeling of microwave heating. The Lambert’s law is quite simple and therefore formulation of the model using ML-based algorithms is easier. However, Maxwell's equations are very complex to develop mathematical modeling, particularly in Multiphysics applications such as food drying. Maxwell equations consist of four vectory equations such as Faraday’s law, Ampère-Maxwell law, Gauss's law for the electric field, and Gauss's law for the magnetic field. Combination of these four different laws is used to solve the electric and magnetic fields. Once the electric and magnetic field distributions are observed, volumetric unit power generation can be calculated based on the Poynting theorem.[128] Due to extreme complexity to express these combine Multiphysics problems by ML-based algorithms, study to develop an ML-based IMCD would be challenging, but once that has huge potential to advance the microwave-based hybrid drying technology.
The mode generation due to the wave transmission phenomena from a loss free isotropic cylindrical metallic waveguide to the semi-bounded plasma waveguide
Published in Waves in Random and Complex Media, 2021
Samaneh Najari, Bahram Jazi, Sajad Jahanbakht
The Maxwell’s equations consist of a set of coupled first-order partial differential equations relating to the components of the electric and the magnetic fields. One of these equations is: Therefore, the magnetic field in terms of a vector potential can be defined