International Journal of Applied Electromagnetics and Mechanics - Volume 15, issue 1-4

Authors: Mihalache, Ovidiu | Chen, Zhenmao | Cranganu-Cretu, Bogdan | Miya, Kenzo

Article Type: Research Article

Abstract: The paper presents new developments in the detection of inner and outer defects in welds by using magnetic methods. A new yoke based on permanent magnets was designed. Signals from different types of cracks, inner and outer, are measured. Difficulties arising in detection of outer defects, in thick welded parts are also discussed.

Keywords: magnetic flux leakage, crack, weld, ferromagnetic material

DOI: 10.3233/JAE-2002-437

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 61-66, 2002

Authors: Jiang, Zhongwei | Fujiwara, Shusuke | Chonan, Seiji | Kawashima, Kazuo

Article Type: Research Article

Abstract: This work is concerned with an experimental study on online measurement of the states of ID saw blade cutting a 12-inch crystal ingot. An online monitoring system consisting of a 3-axis piezoelectric sensor, a three-band digital filter, a digital oscilloscope and computer was developed. Since the acoustical and chatter vibration signals during cutting ingot were complex, they are decomposed in three frequency regions to evaluate the blade extension circumstance, the sharpness of blade edge and the …interference between blade and ingot. The proposed ID-Blade slicer monitoring system is validated for evaluation of the blade slicing 12-inch silicon ingots. Show more

Keywords: ID saw blade, 12inch wafer slicer, online monitoring system

DOI: 10.3233/JAE-2002-429

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 67-72, 2002

Authors: Čápová, Klára | Čáp, Ivo | Faktorová, Dagmar

Article Type: Research Article

Abstract: The present paper deals with the utilization of the electromagnetic-acoustic transducer (EMAT) for the non-destructive testing of conducting materials. The principle of the EMAT consists in the interaction of the electrodynamic structure of materials with an external electromagnetic (EM) field under influence of a bias magnetic field. It offers the possibility to generate an acoustic mode of the penetrating EM wave with the slow velocity and the attenuation of the acoustic wave or on the other …hand to detect the EM wave due to its radiation from the surface of a conducting sample. The main advantage of the EMAT is the contactless generation and detection of the acoustic wave, or the acoustic mode of EM wave in a wide range of frequencies and temperatures. The special properties of EMAT's driving and detecting devices are presented in the paper. Show more

DOI: 10.3233/JAE-2002-432

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 73-77, 2002

Authors: Zhu, Z.Q. | Ede, J.D. | Howe, D.

Article Type: Research Article

Abstract: A design criteria for brushless dc motors for high-speed sensorless operation is described. It is shown that motors can be designed such that the free-wheeling diodes in the power electronic drive have a low conduction angle, while exhibiting high efficiency. Thus, established sensorless commutation strategies based on the detection of the zero-crossing of the back-emf waveform can be employed.

DOI: 10.3233/JAE-2002-446

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 79-87, 2002

Authors: Wakiwaka, Hiroyuki | Kataoka, Yasuhiro | Shinoura, Osamu

Article Type: Research Article

Abstract: Giant magneto-resistive (GMR) elements are applied to several industrial magnetic sensors. This paper deals with the directional sensitivity of GMR elements, and their industrial applications. The use of GMR element has several advantages for other sensors. In the area of data storage, GMR elements are generally used to detect the magnetic field impressed in the direction of the stripe width. However, the GMR element has high sensitivity in the direction of the length as well as …the width, even if it is a stripe shape. In addition, we obtain an omnidirectional sensitivity of GMR elements. Using the GMR element, we developed a GMR line sensor. This sensor visualized a magnetic field by only a single scan. Show more

DOI: 10.3233/JAE-2002-447

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 89-96, 2002

Authors: Wieger, Martin | Hauser, Hans

Article Type: Research Article

Abstract: Lead acid batteries loose their nominal capacity by time due to the normal aging and by sulfatation. More than 500 experiments proved that batteries regain more than 85% of their capacity being regenerated by the described electromagnetic procedure. Results on strongly sulfated lead acid batteries with a loss of capacity more than 90% show a success rate of more than 55%. Doing the regeneration with lead acid batteries which are still functional (loss of capacity less …than 20%), showed that 95% of the nominal capacity could be achieved. Show more

DOI: 10.3233/JAE-2002-450

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 97-102, 2002

Authors: Rizzo, M.

Article Type: Research Article

Abstract: The density distribution of the magnetic field and the overheating distribution were simultaneously submitted to a coupled analysis by the Finite Element Method. A 2-D model was adopted for the magnetic field as well as for the thermal field.

DOI: 10.3233/JAE-2002-504

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 103-110, 2002

Authors: Iida, Satoko | Suzuki, Daisuke | Kambe, Shiro | Ishii, Osamu

Article Type: Research Article

Abstract: We investigated the application of a magnetic ribbon to a highly sensitive magnetic sensor. The sensor employs the impedance change in a coupled magnetic ribbon when a radio frequency (rf) current is passed through it and an external magnetic field is applied. When the non-uniform external field was applied the coupled ribbon structure was conformed to have high sensitivity, which was about ten times higher than that in the uniform external field. This phenomenon was attributed …to the magnetostatic coupling between coupled magnetic ribbons. Show more

DOI: 10.3233/JAE-2002-441

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 111-116, 2002

Authors: Roy, Debabrata | Akiyama, Yosuke | Yamada, Sotoshi | Iwahara, Masayoshi

Article Type: Research Article

Abstract: This paper has reported the development and performance of a flux-concentration type linear induction motor (FCLIM) utilizing the effect of flux-concentration by eddy currents. In the developed FCLIM, the slot-leakage flux is reduced and as a result more flux is concentrated into the air gap. The key element of the FCLIM is the conducting plate inserted between the exciting coils in each slot. Thrust characteristics of conventional tubular LIM and FCLIM are compared using the equivalent …circuit parameters. Though some losses are occurred in the plate, the overall efficiency of FCLIM is better at higher output force. Show more

DOI: 10.3233/JAE-2002-440

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 117-122, 2002

Authors: Akita, Masanori | Tsuboe, Naoki | Midorikawa, Yoichi

Article Type: Research Article

Abstract: This Paper describes the method for effective extraction of spectral features of signals under the noisy environment. Further examination showed that extraction of the features of signals under the noisy environment is possible using modification of spectral envelopes by rule. In this modification method, vanished valleys of spectral envelopes under the noisy environment are recovered. However, the incorrect valleys are sometimes added and the obtained envelopes have bad influences on performance of systems using these features. …In this paper, smoothing functions are used for avoiding wrong spectral valleys by rule and the improvement of performance for extraction of spectral features is shown. Four kinds of smoothing functions are defined and evaluated. Experimental results of pattern recognition using proposed spectral parameters are presented. Show more

DOI: 10.3233/JAE-2002-442

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 123-127, 2002