Effect of Extremely Low-Frequency(ELF) Magnetic Field on Anticancer Drugs Potency

There are some reports about combined effects of electromagnetic fields with known carcinogens, toxic physical or chemical agents. In previous study, we observed that magnetic fields (60 Hz, 50 mT) enhance cytotoxicity of mitomycin C on E.coli bacterium. However, it has not been clear about the effective condition of magnetic fields (magnetic flux density, frequency, exposure time etc.) on the potency of chemical agents. In this study, we investigated the effective density and the action mechanisms of magnetic fields on the enhancement of drugs potency. The result suggested that the enhancing effect of mitomycin C potency by exposure to magnetic fields depended on the magnetic flux density. The potency of cisplatin, widely used in clinical cancer chemotherapy, was also enhanced by exposure to 60 Hz, 50 mT magnetic fields. The analysis of the potency of supernatant remaining drugs in the culture medium indicated that the intracellular drug potency was increased and extracellular drug potency was decreased by exposure to magnetic fields. The values of drug potency revealed a significant inverse correlation between intracellular and extracellular cells. These results suggested that magnetic fields (60 Hz, 50 mT) change the permeability of cell membrane and influence the drug intake

Detection and Distinction of Conductive and Magnetic Security Markers Using Eddy-Current Inspection

A printed magnetic marker is used effectively on bills or check for security. In securing of valuable documents, a further improvement in the degree of security is always indispensable. The addition of a conductive marker as well as a magnetic marker enhances the value of information and the reliability of these markers. We applied an eddy-current testing (ECT) technique by using the micro ECT probe with a giant magneto-resistance element (GMR) to detect both markers. Two markers can be detected and also distinguished by recognizing both the amplitude and phase of the ECT signal. This paper describes the method of detection and the results for these markers printed by a magnetic and conductive ink

Characterized Hysteresis Model and a Magnetic Pulse Compression Circuit

Mathematical model of hysteresis is introduced, and it is characterized to analyze highly saturable magnetic equipment on the effect of specific paramenters. Using this mathematical model, performance of magnetic pulse compression circuit is nemerically analyzed

Harmonic field calculation by the combination of finite element analysis and harmonic balance method

A new finite element analysis for the time- periodic magnetic field calculation is described. An AC magnetic field calculation involving saturation characteristics requires many iterations and much memory region. The combination of FEM and harmonic balance method enables us to economically calculate harmonic magnetic flux distributions at an AC magnetization. The method does not need the calculation concerned with time and the the calculation algorithm is the same on the nonlinear DC field FEM. The method is applied to the magnetic field analysis of a reactor and an electromagnet

Performance of Energy Harvester Using Iron-Gallium Alloy in Free Vibration

We propose a micro energy-harvesting device, using an iron-gallium alloy (Galfenol), capable of generating electrical energy from ambient vibrations. Galfenol is a ductile magnetostrictive material with a high piezomagnetic constant, good machinability, and a large inverse magnetostrictive effect by which magnetization can be varied by mechanical stress. The device consists of two beams of Galfenol combined with iron yokes, coils, and a bias magnet. A bending force applied at the tip of the cantilever yields a flux increase by tensile stress in one beam, and a flux decreases in the other by compression. The time variation of the flux generates a voltage on the wound coils. This energy harvester has advantages over conventional types of device, such as those using piezoelectric materials, with respect to size, and efficiency, and it has high robustness and low electrical impedance. In addition, the structure needs only a low mechanical force to generate electricity. In this paper, the free vibration characteristic to accrue electric energy effectively is examined. From the experimental results, the energy conversion efficiency in the vibration is inverse proportional to the resonant frequency

A Novel Planar Electromagnetic type Bio-sensor for noncontact and noninvasive estimation of fat content in pork meat

金沢大学環日本海域環境研究センター生体機能計測研究部

薄形、低電磁雑音のプレーナ形磁気アクチュエータの研究

金沢大学工学部本研究は,小形メカニカル部品の一部としての数百μmからcmの移動可能な平面形(薄形化)に特徴をもつミヤンダ形コイルからなる平面形磁気アクチュエータの構成法とその特性を検討する研究である。平面形磁気アクチュエータの構成法については,永久磁石をム-バ,励磁コイルとしてミアンダ形コイルをステ-タとする基本構成を選び,平面形磁気アクチュエータを作成した。永久磁石には薄形ストライプ上に励磁したフェライト磁石を採用し,ステ-タには積層磁心を放電加工により作成することを選定した。これらの作成法は,極めて高度な加工技術を必要とした。次に製作した平面形磁気アクチュエータにより,静止推力を測定し従来のリニアパルスモータにおける推力/質量比,推力/体積比を比較し検討を行った。その結果は,当構成の平面構成による放熱性,吸引力特性を考慮すると,平面形磁気アクチュエータは推力/質量比,推力/体積比において従来のリニアパルスモータに匹敵する値を得ることができた。平面形磁気アクチュエータの構造の最適化について,磁気回路解析を行い最大推力を発生する形状について検討を行った。その結果,歯幅には最適値が存在し,その値を実験的にも証明することができた。また,2相リニアパルスモータを製作し過渡特性の検討を行った。本構成の磁気アクチュエータは,磁気回路を細分化することによるステ-タ磁心の磁路断面を極小にすることができ,平面形磁気回路の実現の可能性を持ち,かつ体積あたりの推力は従来の磁気アクチュエータと同等の値を得ることができることが明らかになった。また,磁気回路を細分化することにより磁路からの電磁雑音を抑制することも重要な利点である。研究課題/領域番号:06555079, 研究期間(年度):1994出典：研究課題「薄形、低電磁雑音のプレーナ形磁気アクチュエータの研究」課題番号06555079（KAKEN：科学研究費助成事業データベース（国立情報学研究所）） （https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-06555079/）を加工して作

3-D distribution of flux density and an inference about scalar potential in flux concentration model

This paper deals with the three dimensional analysis of a flux concentration model with two conducting plates placed in parallel between a pair of a.c.-excited coils. We have already presented an analysis for the model with a coarse mesh and volumeless plane coils, as well as newly developed iterative 3-D calculation method. [1] The model analyzed this time has total nodes and elements of about twice as those of the model previously calculated. The flux density distribution is compared with experimental data. Distributions of eddy currents and scalar potentials are also solved. Flux concentration effect in the air-slit and flux reflection effect over a conducting plate are seen more clearly. An inference about the role of scalar potential is obtained from our calculation results

Harmonic balance finite element method taking account of external circuit and motion

The alternating-current electric machines are usually excited by voltage sources and the external elements are connected in the magnetizing circuit. Therefore the magnetic fields including nonlinear characteristics, voltage sources and external circuits should be considered together in the analysis model. Furthermore, the motion effects in field problem of electric machines must be sometimes taken into account. This paper describes a new approach for analyzing the time-periodic nonlinear magnetic field problems considered external circuits and motion in the harmonic domain by using the harmonic balance finite element method. The system equation for governing magnetic field with motion and circuits is investigated. A few applications are discussed