1.

論文

論文
山田, 外史 ; 船津, 常正 ; Yamada, Sotoshi
出版情報: 燃料電池.  4  pp.78-82,  2004.  燃料電池開発情報センター
URL: http://hdl.handle.net/2297/00049196
2.

論文

論文
山田, 外史 ; Yamada, Sotoshi
出版情報: 電気製鋼 = Electric furnace steel.  77  pp.215-223,  2006.  電気製鋼研究会 / 大同特殊鋼株式会社
URL: http://hdl.handle.net/2297/00049200
概要: Eddy-current testing (ECT) technique is a well-known methodology of nondestructive evaluation technique that is usually applied to inspect the material flaws without changing or altering testing materials. Generally, ECT technique is used as crack detection in piping systems of nuclear power plants and as an imperfect welding spot detection on aircrafts. The advantage of ECT technique is to highly sense material conductivity which depends on many variables such as material thickness, crack, aging and etc.. The planar exiting coil and the advanced magnetic sensor instead of the conventional inductive ECT probe enable us to invent the probe structure and its applications. The proposed ECT probe consists of a planar meander coil as exciter and spin-valve type giant magnetoresistive (SV-GMR) sensor. The utilization of SV-GMR as a magnetic sensor of ECT probe provides the feasibility of high-spatial resolution, high-sensitivity to low magnetic fields, and high operating frequency range. Due to the SV-GMR advantages, the inspection of micro defect and the detection of micro conductors can be performed by the proposed ECT probe. We call this system“μ-ECT ”. The advanced SV-GMR sensor improves the on-site ECT system in the previous metal inspection industry and also invents a new application in a different industrial field. We proposed the ECT system to the inspection system to electronic products, the PCB inspection system and the recognition of solder bead for ball-grid array package. Defects on high-density PCB are examined by ECT technique. The inspection evaluates not only imperfections of the PCB conductor but also PCB conductor dimensions and alignment. We discuss the ECT system and the experimental results. 続きを見る
3.

論文

論文
渡邊, 裕之 ; 山田, 外史 ; 伊藤, 光宏 ; Watanabe, Hiroyuki ; Yamada, Sotoshi
出版情報: 電気製鋼 = Electric furnace steel.  79  pp.271-279,  2008.  電気製鋼研究会 / 大同特殊鋼株式会社
URL: http://hdl.handle.net/2297/00049201
概要: Eddy current probe to detect longitudinal discontinuities such as seams of wires and bars has been discussed. Conventional encircling coil is hard to detect the longitudinal discontinuities because of the fundamental principal restriction. Moreover, a system using a rotating probe hardly has an ability to support high-speed inspection. Therefore, a probe with array sensors has been developed to detect the longitudinal discontinuities without mechanical rotor. The spin-valve type giant magnetoresistance (SV-GMR) sensor was used as the detection sensor. It has advantages in high sensitivity, high frequency response characteristic up to 100 MHz, and the integration of the sensor element compared with coil or other magnetic sensors. The probe is constructed from two excitation coils and 36 detection sensors. The excitation coils are encircling type such as the conventional encircling coils and excited by opposite phase each other. The detection sensors are arranged in the directions of surrounding a rod for examination between excitation coils. The probe has the capabilities to detect the longitudinal notches by sequential scanning with detection sensors. In addition, a correction method for eccentric effect is proposed by taking the addition of signals at position of opposed sensor pair. The present study showed that the probe has the ability to detect the longitudinal notch that depth of 0.3 mm with 5 mm air gap. 続きを見る
4.

論文

論文
Roy, Debabrata P. ; Akiyama, Yosuke ; Yamada, Sotoshi ; Iwahara, Masayoshi ; 山田, 外史 ; 岩原, 正吉
出版情報: International Journal of Applied Electromagnetics and Mechanics.  15  pp.117-122,  2001.  The Japan Society of Applied Electromagnetics and Mechanics (JSAEM) = 日本AEM学会
URL: http://hdl.handle.net/2297/00049203
概要: 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. 続きを見る
5.

論文

論文
Tanimoto, Yoshifumi ; Izumi, Syunsuke ; Furuta, Koichi ; Suzuki, Tomoe ; Fujiwara, Yoshihisa ; Fujiwara, Masao ; Hirata, Toshifumi ; Yamada, Sotoshi ; 山田, 外史
出版情報: International Journal of Applied Electromagnetics and Mechanics.  14  pp.311-316,  2001.  The Japan Society of Applied Electromagnetics and Mechanics (JSAEM) = 日本AEM学会
URL: http://hdl.handle.net/2297/00049204
概要: The effects of high magnetic field on Euglena gracilis Z were examined. When a horizontal magnetic field gradient (ca. 400 T2m-1) was applied, living E. gracilis moved to a higher field (positive magnetotaxis), whereas dead one gathered in a lower field. Magnetotaxis was not observed in a uniform magnetic field of 8 T. E. gracilis was oriented almost perpendicularly to the magnetic field regardless of life and death. Magnetotaxis of E. gracilis would be explained by taking into account inhomogeneous magnetic forces on and magnetic orientation of E. gracilis. 続きを見る
6.

論文

論文
Taniguchi, T. ; Nakamura, K. ; Yamada, Sotoshi ; Iwahara, Masayoshi ; 山田, 外史 ; 岩原, 正吉
出版情報: International Journal of Applied Electromagnetics and Mechanics.  14  pp.503-506,  2001.  The Japan Society of Applied Electromagnetics and Mechanics (JSAEM) = 日本AEM学会
URL: http://hdl.handle.net/2297/00049205
概要: This paper presents an image processing method for eddy-current testing for the detection of the defects with a specific orientation. The method utilizes the fact that a line-shaped signal is, through the Fourier transform, mapped onto a line passing through the origin and perpendicular to the orientation of the original signal. Hence, nonseparable fan filters is used to select the frequency components corresponding to the defects orientated in a Specific direction. This approach enables more precise control of the extraction characteristics of signals compared to the iterative application of one-dimensional (1-D) filtering in the vertical and horizontal directions, in which the shape of the pass band is restricted to a geometry made from squares. The effectiveness of the proposed method is shown by a demonstration using a metallic sample with a defect aligned in a number of directions. 続きを見る
7.

論文

論文
Mukhopdhyay, S.C. ; Yamada, Sotoshi ; Iwahara, Masayoshi ; 岩原, 正吉 ; 山田, 外史
出版情報: International Journal of Applied Electromagnetics and Mechanics.  15  pp.323-329,  2001.  The Japan Society of Applied Electromagnetics and Mechanics (JSAEM) = 日本AEM学会
URL: http://hdl.handle.net/2297/00049206
概要: This paper has investigated the possibility of applying nondestructive evaluation technique for finding the defects in electroplated materials. Planar meander and mesh type magnetic sensors have been considered and their relative performance have been compared based on a single criterion that the effective area of the material surface covered by each type of sensor is same. 続きを見る
8.

論文

論文
Mukhopdhyay, S.C. ; Iwahara, Masayoshi ; Yamada, Sotoshi ; 岩原, 正吉 ; 山田, 外史
出版情報: International Journal of Applied Electromagnetics and Mechanics.  14  pp.47-50,  2001.  The Japan Society of Applied Electromagnetics and Mechanics (JSAEM) = 日本AEM学会
URL: http://hdl.handle.net/2297/00049207
概要: For the last few years the authors have been involved in the design and development of different topologies of magnetic current limiter (MCL). The small scale laboratory models have been fabricated and experiments were conducted. The simulated performance obtained from the tableau approach based on lumped parameter model shows discrepancy with the experiment. This paper describes the necessity of electromagnetic field computation which clearly shows the discrepancy between the observed and the simulation results, which can be attributed to a non uniform flux distribution in the core. 続きを見る
9.

論文

論文
Miyakawa, T. ; Harada, S. ; Ishimori, T. ; Yamamoto, H. ; Hosono, R. ; Yamada, Sotoshi ; 山田, 外史
出版情報: International Journal of Applied Electromagnetics and Mechanics.  14  pp.323-326,  2001.  The Japan Society of Applied Electromagnetics and Mechanics (JSAEM) = 日本AEM学会
URL: http://hdl.handle.net/2297/00049208
概要: Responses of the small heat shock protein gene, hsp-16, were examined in transgenic Caenorhabditis elegans exposed to extremely low frequency magnetic fields (ELFMFs). Expression of the hsp-16-lacZ gene was enhanced when transgenic animals were exposed to magnetic fields up to 0.5 T at 60 Hz. The hsp-16 promoter was more efficiently expressed at the embryonic than at the post-embryonic stage irrespective of exposure. Promoter activity was more sensitive to the stimulus in the intestine at the post-embryonic stage. Evidence is presented that the induction occurs at the transcriptional step of hsp-16. 続きを見る
10.

論文

論文
Kacprzak, D. ; Yamada, Sotoshi ; Iwahara, Masayoshi ; 山田, 外史 ; 岩原, 正吉
出版情報: International Journal of Applied Electromagnetics and Mechanics.  15  pp.15-19,  2001.  The Japan Society of Applied Electromagnetics and Mechanics (JSAEM) = 日本AEM学会
URL: http://hdl.handle.net/2297/00049209
概要: This paper presents simulated amplitude and phase characteristics obtained during the inspection of printed circuit board by an eddy-current testing probe. The simulation is based on the "two-components" nature of the output signal. Amplitude and phase characteristics, obtained during the experimental inspection and simulation, are presented. 続きを見る