International Journal of Applied Electromagnetics and Mechanics - Volume 34, issue 1-2

Authors: Kaushik, K. | Kulkarni, S.V.

Article Type: Research Article

Abstract: In this paper, we present an analysis of a two-dimensional electric circuit-electromagnetic field coupled problem using the wavelet-Galerkin method. For illustration, the bar-plate configuration, a basic model for analysing eddy current phenomenon in electrical apparatus, is chosen. Firstly, a brief description of wavelet theory and its application in computational electromagnetics is provided. Then, a description of the two-dimensional coupled problem formulation and its solution using the wavelet-Galerkin method is given. Finally, results …obtained using simulation are presented. Show more

Keywords: Computational electromagnetics, wavelet-Galerkin method, 2D analysis, coupled-circuit analysis, wavelet bases

DOI: 10.3233/JAE-2010-1081

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 34, no. 1-2, pp. 1-19, 2010

Authors: Takanashi, Hiroyuki | Tanaka, Mami | Tanahashi, Yoshikatsu | Chonan, Seiji

Article Type: Research Article

Abstract: This paper proposes a three-dimensional tactile sensor that can be attached to the tip of an endoscope or catheter to detect the tip contact conditions. Because conventional minimally invasive instruments (MIIs) without a sensor cannot detect the posture and applied force at the tip, operators cannot obtain accurate information during minimally invasive surgery (MIS). The sensor consists of an elastic cylinder and three strain gauges. The gauges, located on the surface of the cylinder at intervals …of 120°, are used to detect deformation of the cylinder caused by contact with the inner walls of the patient's organs. The output voltage signals of the gauges are approximated by a sinusoidal function with a phase difference of 120°. The three-dimensional contact angle and applied force at the tip of the sensor can be estimated accurately from the three sinusoidal functions and measured output voltage signal from the gauges. The operating principle of the sensor is examined through several experimental conditions. Show more

Keywords: Minimally invasive therapy, tactile sensor, strain gauge, minimally invasive instrument

DOI: 10.3233/JAE-2010-1084

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 34, no. 1-2, pp. 21-32, 2010

Authors: Sun, Chi Hsien | Chiu, Chien-Ching | Lin, Chun Jen

Article Type: Research Article

Abstract: The image reconstruction of inhomogeneous biaxial dielectric cylinders buried in a slab medium is investigated. A biaxial dielectric cylinder of unknown permittivities buried in a slab scatters a group of unrelated incident waves from outside. The scattered field is recorded outside the slab. By proper arrangement of the various unrelated incident fields, the difficulties of ill-posedness and nonlinearity are circumvented, and the permittivity distribution can be reconstructed through simple matrix operations. The …algorithm is based on the moment method and the unrelated illumination method. Numerical results are given to demonstrate the capability of the inverse algorithm. Good reconstructed results are obtained even in the presence of additive Gaussian random noise in measured data. In addition, the effect of noise on the reconstruction result is also investigated. Show more

DOI: 10.3233/JAE-2010-1085

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 34, no. 1-2, pp. 33-48, 2010

Authors: Merit, B. | Remy, M. | Lemarquand, G. | Lemarquand, V.

Article Type: Research Article

Abstract: This paper first presents the principle of the electrodynamic loudspeaker. It particularly shows how few evolutions occurred since the first device was designed. Then, it describes the loudspeaker drawbacks whose sources lie in the motor – especially because of the iron-, the moving part and the suspension. Furthermore, the major goal of this paper is to propose examples of evolutions which suppress some of the drawbacks. So, the motors presented are ironless, made with permanent magnets …only. Their structure can be optimized to create very uniform magnetic fields in the air gap where a short coil is totally submitted to the field. Moreover, the elastomer suspensions are replaced by ferrofluid seals which guide the moving part. Besides, the moving part itself becomes a lightweight rigid bulk piston. Eventually, these proposals prove that evolution of the electrodynamic loudspeaker is still possible. And the possibilities are of course myriads. Show more

Keywords: Loudspeaker, permanent magnet, ferrofluid

DOI: 10.3233/JAE-2010-1086

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 34, no. 1-2, pp. 49-61, 2010

Authors: Gao, Yang

Article Type: Research Article

Abstract: Without employing ad hoc assumptions, various equations and solutions for magnetoelastic beams are deduced systematically and directly from the two-dimensional magnetoelasticity. These equations and solutions can be used to construct the refined theory of magnetoelastic beams for tension and compression deformation. By using the general solution for the soft ferromagnetic elastic solids and the Lur'e method, the refined theory can now be explicitly established. In the case of homogeneous boundary conditions, the …exact governing differential equations and solutions for beams are derived, which consist of three governing differential equations. In the case of non-homogeneous boundary conditions, a traction free boundary condition is considered. In two illustrative examples of beams, it is shown that the exact or accurate solutions can be obtained in use of the refined theory deduced herein. Show more

Keywords: Magnetoelastic beams, tension and compression deformation, the refined theory, governing equation

DOI: 10.3233/JAE-2010-1087

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 34, no. 1-2, pp. 63-71, 2010

Authors: Li, Ching-Lieh | Chien, Wei | Huang, Chung-Hsin | Chiu, Chien-Ching

Article Type: Research Article

Abstract: This paper presents the studies of time domain inverse scattering for a two dimensional homogeneous dielectric cylinder buried in a half-space which are based on the finite difference time domain (FDTD) method and the dynamic differential evolution (DDE). For the forward scattering, the FDTD method is employed to calculate the scattered E fields, while for the inverse scattering the DDE scheme is utilized to determine the shape, location and the permittivity of the buried cylindrical scatterer …with arbitrary cross section. The subgirdding technique is implemented for the FDTD code in order to model the shape of the cylinder more smoothly. In additions, in order to describe an unknown cylinder with arbitrary cross section more effectively during the course of searching, the closed cubic-spline expansion is adopted to represent the scatterer contour instead of the frequently used trigonometric series. Numerical results demonstrate that, even when the initial guess is far away from the exact one, good reconstruction can be obtained. In addition, the effects of Gaussian noise on the reconstruction results are investigated. Numerical results show that even the measured scattered fields are contaminated with Gaussian noise, DDE is able to yield good reconstructed quality. Show more

Keywords: Time domain inverse scattering, FDTD, subgridding, dynamic differential evolution, homogenous dielectric cylinder

DOI: 10.3233/JAE-2010-1088

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 34, no. 1-2, pp. 73-86, 2010

Authors: Jiang, Zhongwei | Chen, Guoming | Kawazu, Takaaki | Morita, Minoru

Article Type: Research Article

Abstract: Liposomes as a drug delivery system have been an attracting interest to many researchers. This paper concerns with the study on how to control the release rate of the inner-substances from liposomes by the ultrasonic irradiation. Two kinds of ultrasonic control methods are tested for investigation of the efficiency of the release property of the liposomes. One control method is to increase the input power by fixing its frequency at a frequency near the probe resonant …frequencies. Another method is to adjust the input frequency around the probe resonant frequencies but fixing the input power. In the experiments, three kinds of liposomes with different lipid ratio were prepared and calcein as an indicator was enclosed into the liposomes. The release effect was evaluated from the fluorescence intensity changes which was measured by a spectrofluorometer. The results showed that the efficient release property could be achieved both by control of the input power and the input frequency, but adjusting the input frequency around the probe resonant frequency can get higher efficient release performance than that controlled by the input power. Show more

Keywords: Drug delivery system, liposome, release control, ultrasonic irradiation, resonant frequency

DOI: 10.3233/JAE-2010-1089

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 34, no. 1-2, pp. 87-98, 2010

Authors: Singh, Udaybir | Kumar, Narendra | Kumar, Nitin | Bera, A. | Purohit, L.P. | Sinha, A.K.

Article Type: Research Article

Abstract: A triode-type magnetron injection gun (MIG) for a 42 GHz, 200 kW gyrotron was designed by two commercial codes: EGUN and TRAK. An in-house code MIGANS was used as the post-processor of the EGUN. Some basic equations relevant to the problem available in literature were used while using the EGUN code for the purpose. The results on the design output parameters obtained by these two codes were found to be in close agreement.

Keywords: Magnetron injection gun, gyrotron, gyro-device, electron gun, tokamak, plasma heating, thermonuclear energy

DOI: 10.3233/JAE-2010-1090

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 34, no. 1-2, pp. 99-107, 2010

Authors: Zou, Huiming | Zhang, Liqin | Peng, Guohong | Tian, Changqing

Article Type: Research Article

Abstract: Linear oscillation motor (LOM) is the key assembly for a linear compressor, and its efficiency has great impact on the integral compressor performance. This paper presents a novel gas load method to measure the efficiency of LOM, analyses the effects of some main factors on the LOM efficiency in theory, and shows the efficiency test results. Different load conditions can be simulated by adjusting the discharge pressure of the gas and the load force presents nonlinear …periodical curve. In the experiment, we changed the syntonic springs of the tested LOM to measure the LOM efficiency on different work conditions. The results of both theoretical analysis and experiment show that the LOM efficiency is the highest when the phase angle between current and displacement is 90°. While the springs stiffness coefficient is 54.44N/mm, the highest efficiency of the tested LOM is 85.97% on the condition that the discharge pressure is 0.25MPa. While the springs stiffness coefficient is 44.64N/mm the highest efficiency of the tested LOM is 84.67% on the condition that the discharge pressure is 0.4MPa. While the springs stiffness coefficient is 38.4N/mm the highest efficiency of the tested LOM is 78.35% on the condition that the discharge pressure is 0.5MPa. Show more

Keywords: Linear oscillation motor, moving-magnet, linear compressor, efficiency measurement

DOI: 10.3233/JAE-2010-1304

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 34, no. 1-2, pp. 109-118, 2010

Authors: Wang, B.L. | Hoffman, M.

Article Type: Research Article

Abstract: This paper studies the problem of a line inclusion in a medium possessing coupled piezoelectric, piezomagnetic and magnetoelectric effects. Based on the extended Stroh formalism, the general two-dimensional solutions to the magnetoelectroelastic problem are obtained, involving five analytic functions of different variables. The magnetic, electric and elastic fields around the inclusion are given. Expressions of the stresses, electric field and magnetic field in the vicinity of the inclusion tip are derived and the field …intensity factors are provided. The energy release rate is written in terms of those field intensity factors. Solutions for some special cases, including the electrically and/or magnetically insulated/conductive inclusions/cracks, are also established. Explicit algebraic results are given for a special case of an anti-plane crack in a magnetoelectroelastic medium. Show more

Keywords: Fracture mechanics, magnetoelectroelasticity, inclusion

DOI: 10.3233/JAE-2010-1305

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 34, no. 1-2, pp. 119-129, 2010