-
1كتاب
المؤلفون: Ulloa, Rafael Zamorano
المصدر: https://wwwTest.intechopen.com/books/9878.
الوصف: Detailed electrodynamic descriptions of the fundamental workings of microwave heating devices are presented. We stress that all results come from Maxwell equations and the boundary conditions (BC). We analyze one by one the principal components of a microwave heater; the cooking chamber, the waveguide, and the microwave sources, either klystron or magnetron. The boundary conditions at the walls of the resonant cavity and at the interface air/surface of the food are given and show how relevant the BC are to understand how the microwaves penetrate the nonconducting, electric polarizable specimen. We mention the application of microwaving waste plastics to obtain a good H2 quantity that could be used as a clean energy source for other machines. We obtained trapped stationary microwaves in the resonant cavity and traveling waves in the waveguides. We show 3D plots of the mathematical solutions and agree quite well with experimental measurements of hot/cold patterns. Simulations for cylindrical cavities are shown. The radiation processes in klystrons and magnetrons are described with some detail in terms of the accelerated electrons and their trajectories. These fields are sent to the waveguides and feed the cooking chamber. Whence, we understand how a meal or waste plastic, or an industrial sample is microwave heated.
العلاقة: https://mtsTest.intechopen.com/articles/show/title/electromagnetism-of-microwave-heating
الإتاحة: https://doi.org/10.5772Test/intechopen.97288
https://mtsTest.intechopen.com/articles/show/title/electromagnetism-of-microwave-heating -
2كتاب
المؤلفون: Singh, Sukhmander, Tyagi, Ashish, Vidhani, Bhavna
المصدر: https://wwwTest.intechopen.com/books/9878.
الوصف: The chapter is divided into two parts. In the first part, the chapter discusses the theory of propagation of electromagnetic waves in different media with the help of Maxwell’s equations of electromagnetic fields. The electromagnetic waves with low frequency are suitable for the communication in sea water and are illustrated with numerical examples. The underwater communication have been used for the oil (gas) field monitoring, underwater vehicles, coastline protection, oceanographic data collection, etc. The mathematical expression of penetration depth of electromagnetic waves is derived. The significance of penetration depth (skin depth) and loss angle are clarified with numerical examples. The interaction of electromagnetic waves with human tissue is also discussed. When an electric field is applied to a dielectric, the material takes a finite amount of time to polarize. The imaginary part of the permittivity is corresponds to the absorption length of radiation inside biological tissue. In the second part of the chapter, it has been shown that a high frequency wave can be generated through plasma under the presence of electron beam. The electron beam affects the oscillations of plasma and triggers the instability called as electron beam instability. In this section, we use magnetohydrodynamics theory to obtain the modified dispersion relation under the presence of electron beam with the help of the Poisson’s equation. The high frequency instability in plasma grow with the magnetic field, wave length, collision frequency and the beam density. The growth rate linearly increases with collision frequency of electrons but it is decreases with the drift velocity of electrons. The real frequency of the instability increases with magnetic field, azimuthal wave number and beam density. The real frequency is almost independent with the collision frequency of the electrons.
العلاقة: https://mtsTest.intechopen.com/articles/show/title/physics-of-absorption-and-generation-of-electromagnetic-radiation
الإتاحة: https://doi.org/10.5772Test/intechopen.99037
https://mtsTest.intechopen.com/articles/show/title/physics-of-absorption-and-generation-of-electromagnetic-radiation -
3كتاب
المؤلفون: Kanjaa, Mohammed, El Mrabet, Otman, Khalladi, Mohsine
المصدر: https://wwwTest.intechopen.com/books/9878.
الوصف: An auxiliary differential equation (ADE) transmission line method (TLM) is proposed for broadband modeling of electromagnetic (EM) wave propagation in biological tissues with the Cole-Cole dispersion Model. The fractional derivative problem is surmounted by assuming a linear behavior of the polarization current when the time discretization is short enough. The polarization current density is approached using Lagrange extrapolation polynomial and the fractional derivation is obtained according to Riemann definition of a fractional α-order derivative. Reflection coefficients at an air/muscle and air/fat tissues interfaces simulated in a 1-D domain are found to be in good agreement with those obtained from the analytic model over a broad frequency range, demonstrating the validity of the proposed approach.
العلاقة: https://mtsTest.intechopen.com/articles/show/title/a-tlm-formulation-based-on-fractional-derivatives-for-dispersive-cole-cole-media
الإتاحة: https://doi.org/10.5772Test/intechopen.96378
https://mtsTest.intechopen.com/articles/show/title/a-tlm-formulation-based-on-fractional-derivatives-for-dispersive-cole-cole-media -
4كتاب
المؤلفون: Zhang, Ling, Feng, Yuru, Fan, Jun, Li, Er-Ping
المصدر: https://wwwTest.intechopen.com/books/9878.
الوصف: Electromagnetic interference (EMI) is becoming more troublesome in modern electronic systems due to the continuous increase of communication data rates. This chapter reviews some new methodologies for high-frequency EMI diagnostics in recent researches. Optical modules, as a typical type of gigahertz radiator, are studied in this chapter. First, the dominant radiation modules and EMI coupling paths in an explicit optical module are analyzed using simulation and measurement techniques. Correspondingly, practical mitigation approaches are proposed to suppress the radiation in real product applications. Moreover, an emission source microscopy (ESM) method, which can rapidly localize far-field radiators, is applied to diagnose multiple optical modules and identify the dominant sources. Finally, when numerous optical modules work simultaneously in a large network router, a formula based on statistical analysis can estimate the maximum far-field emission and the probability of passing electromagnetic compatibility (EMC) regulations. This chapter reviews a systematic procedure for EMI diagnostics at high frequencies, including EMI coupling path analysis and mitigation, emission source localization, and radiation estimation using statistical analysis.
العلاقة: https://mtsTest.intechopen.com/articles/show/title/high-frequency-electromagnetic-interference-diagnostics
الإتاحة: https://doi.org/10.5772Test/intechopen.97613
https://mtsTest.intechopen.com/articles/show/title/high-frequency-electromagnetic-interference-diagnostics -
5كتاب
المؤلفون: Raad, Shiva Hayati, Atlasbaf, Zahra
المصدر: https://wwwTest.intechopen.com/books/9878.
الوصف: The integral equation (IE) method is one of the efficient approaches for solving electromagnetic problems, where dyadic Green’s function (DGF) plays an important role as the Kernel of the integrals. In general, a layered medium with planar, cylindrical, or spherical geometry can be used to model different biomedical media such as human skin, body, or head. Therefore, in this chapter, different approaches for the derivation of Green’s function for these structures will be introduced. Due to the recent great interest in two-dimensional (2D) materials, the chapter will also discuss the generalization of the technique to the same structures with interfaces made of isotropic and anisotropic surface impedances. To this end, general formulas for the dyadic Green’s function of the aforementioned structures are extracted based on the scattering superposition method by considering field and source points in the arbitrary locations. Apparently, by setting the surface conductivity of the interfaces equal to zero, the formulations will turn into the associated problem with dielectric boundaries. This section will also aid in the design of various biomedical devices such as sensors, cloaks, and spectrometers, with improved functionality. Finally, the Purcell factor of a dipole emitter in the presence of the layered structures will be discussed as another biomedical application of the formulation.
العلاقة: https://mtsTest.intechopen.com/articles/show/title/dyadic-green-s-function-for-multilayered-planar-cylindrical-and-spherical-structures-with-impedance-
الإتاحة: https://doi.org/10.5772Test/intechopen.95834
https://mtsTest.intechopen.com/articles/show/title/dyadic-green-s-function-for-multilayered-planar-cylindrical-and-spherical-structures-with-impedance- -
6كتاب
المؤلفون: Lacy, Fred
المصدر: https://wwwTest.intechopen.com/books/9878.
الوصف: Superconductors have a wide array of applications, such as medical imaging, supercomputing, and electric power transmission, but superconducting materials only operate at very cold temperatures. Thus, the quest to engineer room temperature superconductors is currently a hot topic of research. To accomplish this mission, it is important to have a complete understanding of the material properties that are being used to create these superconductors. Understanding the atomic and electromagnetic properties of the prospective materials will provide tremendous insight into the best choice for the materials. Therefore, a theoretical model that incorporates electromagnetic field theory and quantum mechanics principles is utilized to explain the electrical and magnetic characteristics of superconductors. This model can be used to describe the electrical resistance response and why it vanishes at the material’s critical temperature. The model can also explain the behavior of magnetic fields and why some superconducting materials completely exclude magnetic fields while other superconductors partially exclude these fields. Thus, this theoretical analysis produces a model that describes the behavior of both type I and type II superconductors. Since there are subtle differences between superconductors and perfect conductors, this model also accounts for this distinction and explains why superconductors behave differently than perfect conductors. Therefore, this theory addresses the major properties associated with superconducting materials and thus will aid researchers in the pursuit of designing room temperature superconductors.
العلاقة: https://mtsTest.intechopen.com/articles/show/title/using-electromagnetic-properties-to-identify-and-design-superconducting-materials
الإتاحة: https://doi.org/10.5772Test/intechopen.97327
https://mtsTest.intechopen.com/articles/show/title/using-electromagnetic-properties-to-identify-and-design-superconducting-materials -
7كتاب
المؤلفون: Rampim, Renata, de Pieri Baladei, Ivan
المصدر: https://wwwTest.intechopen.com/books/9878.
الوصف: The use of the UHF RFID system in a warehouse that contains steel coils is a challenge for the technology itself since there are countless reflections of the radio frequency waves in the environment causing the multipath effect, which represents one of the most complex problems for wireless communication. Thus, this effect must be managed with the hardware, such as the antenna radiation diagram, and with the software, in the middleware, the software developed for the application. In this chapter, an application of RFID in metallic items will be discussed, tracking them since the product’s hot rolling, controlling the receiving process, shipping, and inventory, working together with equipment such as overhead crane.
العلاقة: https://mtsTest.intechopen.com/articles/show/title/uhf-rfid-in-a-metallic-harsh-environment
الإتاحة: https://doi.org/10.5772Test/intechopen.95611
https://mtsTest.intechopen.com/articles/show/title/uhf-rfid-in-a-metallic-harsh-environment -
8كتاب
المؤلفون: Kasiri, Narges
المصدر: https://wwwTest.intechopen.com/books/9878.
الوصف: Radio Frequency Identification (RFID) technology is one of the latest product tracking technologies being utilized by retailers. Operations management improvements were among the first recognized applications of this technology earlier in the century. RFID applications in managing retail operations, such as inventory management and control, lead to significant benefits. However, RFID applications are not limited to operations management and go beyond the operations side to offer improvements in other areas in retail such as marketing and managing customers’ shopping experiences. In this research, we review the applications of RFID technology in retail since its introduction and how those applications have evolved over the last two decades to help retailers provide omnichannel services to their customers in the current market. We will demonstrate what strategic and tactical factors have helped retailers implement this technology and what factors have slowed down the process of adoption. We will also report on the latest status of the utilization of RFID in the retail sector.
العلاقة: https://mtsTest.intechopen.com/articles/show/title/rfid-applications-in-retail
الإتاحة: https://doi.org/10.5772Test/intechopen.95787
https://mtsTest.intechopen.com/articles/show/title/rfid-applications-in-retail -
9كتاب
المؤلفون: Hafdallah, Abdelhak, Abdelli, Mouna
المصدر: https://wwwTest.intechopen.com/books/9878.
الوصف: This chapter concerns the optimal control problem for an electromagnetic wave equation with a potential term depending on a real parameter and with missing initial conditions. By using both the average control notion introduced recently by E. Zuazua to control parameter depending systems and the no-regret method introduced for the optimal control of systems with missing data. The relaxation of averaged no-regret control by the averaged low-regret control sequence transforms the problem into a standard optimal control problem. We prove that the problem of average optimal control admits a unique averaged no-regret control that we characterize by means of optimality systems.
العلاقة: https://mtsTest.intechopen.com/articles/show/title/averaged-no-regret-control-for-an-electromagnetic-wave-equation-depending-upon-a-parameter-with-inco
الإتاحة: https://doi.org/10.5772Test/intechopen.95447
https://mtsTest.intechopen.com/articles/show/title/averaged-no-regret-control-for-an-electromagnetic-wave-equation-depending-upon-a-parameter-with-inco -
10كتاب
المؤلفون: Krzysztofik, Wojciech Jan
المصدر: https://wwwTest.intechopen.com/books/6531.
مصطلحات موضوعية: Antennas and Wave Propagation
الوصف: As the growing demand for mobile communications is constantly increasing, the need for better coverage, improved capacity, and higher transmission quality rises. Thus, a more efficient use of the radio spectrum and communication systems availability are required. This chapter presents EM propagation models most commonly used for the design of wireless communication systems, computer networks WLAN and WPAN for urban and/or in indoor environments. The review of commercial or University computer codes to assist design of WLAN and WPAN networks were done. An example of computer design and simulation of indoor Bluetooth and WLAN communication systems, in the building of Wroclaw University of Science and Technology, Wroclaw, Poland is shown in Chapter 8.
العلاقة: https://mtsTest.intechopen.com/articles/show/title/radio-network-planning-and-propagation-models-for-urban-and-indoor-wireless-communication-networks
الإتاحة: https://doi.org/10.5772Test/intechopen.75384
https://mtsTest.intechopen.com/articles/show/title/radio-network-planning-and-propagation-models-for-urban-and-indoor-wireless-communication-networks
