International Journal of Applied Electromagnetics and Mechanics - Volume 35, issue 2

Authors: Miano, Giovanni | Rubinacci, Guglielmo | Tamburrino, Antonello

Article Type: Research Article

Abstract: This contribution is a review paper, concerning mainly the research work made by the authors, about the numerical modeling, in the frequency domain, of both surface and bulk plasmon oscillations induced in metallic nanoparticles with arbitrary shapes by an external electromagnetic field. Surface plasmons are governed by a local constitutive relation, whereas bulk plasmons are governed by a constitutive relation that is expressed by a partial differential equation. The electromagnetic field scattered by the nanoparticles …is evaluated using an integral formulation. In nanoparticles with maximum linear dimensions much smaller than the vacuum wavelength the plasmon dynamic may be studied approximately by using the electro quasi-stationary approximation of the Maxwell equations. The paper discusses both a full-wave integral formulation, where the unknown is the induced current density, and an electro quasi-stationary integral formulation, where the unknown is the surface charge density. Show more

DOI: 10.3233/JAE-2011-1331

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 35, no. 2, pp. 79-91, 2011

Authors: Rybin, Oleg

Article Type: Research Article

Abstract: In this paper, Effective Medium Theory for two-component metamaterial media as infinite host dielectric medium embedded periodically with cylindrical iron inclusions and spherical ones saturated with an external biasing magnetic field is developed in the microwave frequencies. The long wave approximation of effective permeability tensors for the considered metamaterial media has been obtained using the microwave extension of Effective Medium Approximation for polycrystalline ferrites and the long wave approximation of expressions of …the effective magnetic permeability for two-component undiluted metal-dielectric composites with infinitely long non-magnetic metal cylindrical and spherical inclusions. The effective magnetic properties of the metamaterial media for the case of microwave propagation transverse to bias have been studied. It is shown that the considered metamaterial can exhibit the ultra-low refractive index phenomenon and the phenomenon of negative magnetic permeability for the case of microwave propagation transverse to bias. An erratum to this article can be found in [International Journal of Applied Electromagnetics and Mechanics 35(4), 2011, 307], http://iospress.metapress.com/content/v5q6821720352105/fulltext.pdf Show more

Keywords: Metamaterials, effective medium theory, metaferrite, ultra-low index, left-hand materials

DOI: 10.3233/JAE-2011-1323

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 35, no. 2, pp. 93-101, 2011

Authors: Seçkin Gürel, Çiŭdem | Yenilmez, Rumeysa

Article Type: Research Article

Abstract: In this paper, two different methods for the determination of resonant frequency of parallel plate type uniaxially anisotropic multilayered cylindrical dielectric resonator are firstly presented for dominant TE_{0ml} and TM_{0ml} modes. The first method called as Effective Permittivity Approach (EPA) mainly depends on the determination of single effective permittivity of the multilayered structure. The second method, Weighted Frequency Approach (WFA), depends on the evaluation of resonant frequency …of the multilayered structure by weighting the resonant frequencies of each layer. Obtained results using these two approaches are close to each other indicating resonant frequency of uniaxially anisotropic multilayered resonator can be tuned by adjusting the segment parameters. Therefore, in its multilayered form, cylindrical dielectric resonator designed with uniaxial materials will exhibit some advantages over isotropic single layered resonator providing flexible operational characteristics. According to the presented results, application areas of cylindrical dielectric resonator in its proposed form will increase especially in future microwave and communication systems applications as a promising structure. Show more

Keywords: Dielectric rod resonator, multilayered cylindrical resonator, modal analysis, resonant frequency, uniaxial anisotropy, effective permittivity

DOI: 10.3233/JAE-2011-1324

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 35, no. 2, pp. 103-112, 2011

Authors: Desai, S.V. | Kumar, Satendra | Satyamurthy, P. | Chakravartty, J.K. | Chakravarthy, D.P.

Article Type: Research Article

Abstract: In Electromagnetic Welding process, the electromagnetic parameters govern the welding process. The collision velocity is the crucial parameter that decides the quality of the weld joint. The EMW process is comparatively less efficient for low electrical conductivity metals. However, the efficiency of the process can be improved by using high electrical conductivity metals, such as copper, aluminum (named as `drivers') which are placed adjacent to the job piece. In this paper, the performance of different driver …materials is analyzed. This exercise is important from the point of view of minimization of input energy. The computation of the collision velocity is carried out by commercial software's. The results are verified with experimental observations. The job pieces chosen are flat strips of aluminum, copper and S.S. Needless to say, the conclusions drawn are applicable to any other geometry. Since the EM forming process precedes the EMW process, the conclusions are also applicable in the case of the former process. Show more

Keywords: Electromagnetic welding, impact collision velocity, capacitor bank, Lorentz force, ringing frequency, current skin depth

DOI: 10.3233/JAE-2011-1325

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 35, no. 2, pp. 113-121, 2011

Authors: Nemoto, Yoshiyuki | Keyakida, Satoshi | Uchimoto, Tetsuya | Takaya, Shigeru | Tsukada, Takashi

Article Type: Research Article

Abstract: The authors previously reported that magnetic flux leakage data, measured using a flux gate (FG) sensor, showed a correlation with the irradiation-assisted stress corrosion cracking (IASCC) susceptibility of neutron-irradiated austenitic stainless alloys. This paper presents a study conducted to develop a diagnostic system that can detect IASCC precursors in stainless steels by measuring the magnetic properties of the material. The eddy current method and alternating current (AC) magnetization method were used, as …these will be more practical for use in actual reactors. Probes were developed for these measurement methods, providing sufficient tolerance for environments in nuclear reactors. An attempt was also made to improve spatial resolution by manufacturing a smaller probe. A sensor system was designed for remote control, performance tests were conducted by measuring neutron-irradiated specimens and mock specimens, and magnetic data were evaluated by comparing the IASCC susceptibility of the specimens. It was proved that the sensor system developed in this study is capable of detecting IASCC precursors. Further developments necessary for application in actual nuclear reactors and the mechanism of correlation between magnetic properties and IASCC susceptibility were also discussed. Show more

Keywords: Nuclear reactor, IASCC, austenitic stainless steel, prediction, irradiation

DOI: 10.3233/JAE-2011-1326

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 35, no. 2, pp. 123-139, 2011

Authors: Taşkin, Halit | Gürleyük, Sırrı Sunay | Saraç, Zehra

Article Type: Research Article

Abstract: A Tesla transformer is a source that can generate high voltage with high frequency. It is also known a resonance system becomes two air cored coils. Classic Tesla transformer system consists of a high voltage generator which is usually a Neon Sign Transformer (NST), high voltage capacitor and spark gap electrodes. This paper presents mathematical analysis of the equivalent circuit, measure/calculation of its parameters, reasons of resonance, examine of resonance frequencies and a simple solid state …driver with a low voltage in the primary side for a Tesla transformer. Show more

Keywords: Tesla transformer, resonance, high-voltage techniques, frequency response, magnetic devices

DOI: 10.3233/JAE-2011-1327

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 35, no. 2, pp. 141-150, 2011