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Magnetic Properties of Non-Oriented Electrical Steels under Compressive Stress Normal to Their Surface

Yamamoto K., Yanase S.

Przegląd Elektrotechniczny

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2011

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R. 87, nr 9b

97-100

EN

Magnetic properties of non-oriented electrical steels are measured under a compressive stress up to 28 MPa normal to their surface. It is shown that the perpendicular stress changes their permeability and magnetic losses along their circumferential direction. The variations in magnetic properties are discussed in terms of changes in magnetic domains due to the stress.

PL

Zbadano wpływ naprężeń ściskających na niezorientowane blachy elektrotechniczne. Stosowano naprężenia do 28 MPa normalne do powierzchni. Stwierdzono że naprężenia prostopadłe powodują zmiany przenikalności i strat w obu kierunkach.

2

Study on new float polishing with the MCF

Shimada K., Matsuo Y., Yamamoto K., Zheng Y.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 23, nr 2

91-94

EN

Purpose: As a continuation of a previous paper, the report demonstrates the various possibilities of float polishing utilizing the present improved magnetic compound fluid (MCF). The MCF developed by one authors, Shimada, in 2001, was improved by the addition of alpha-cellulose, thereby achieving a clearance as great as 8 mm as shown in another paper. The present paper describes the possibility of the application of the MCF float polishing technique with alpha-cellulose. Design/methodology/approach: First, the results obtained under various polishing conditions of the MCF float polishing technique are described. These conditions include the various shapes of the magnet employed in the polishing tool, magnetic field strength, the concentration of alpha-cellulose, the motion of the specimen, the existence of a magnet fixed underneath the polished specimen, and initial surface roughness. Secondly, the present MCF float polishing technique can be used in many types of polishing, including polishing the inner surface of an acrylic resin tube, a wide flat surface through the use of a orbital polishing tool, and simultaneous float polishing of all surfaces of a three-dimensional complex shape. In addition, as other examples, the polishing on the integrated circuit (IC) substrate is shown. Findings: By the various polishing conditions of the MCF float polishing technique, the polishing effect is changed. On the other hand, as for the many applications of the MCF float polishing, inner surface, wide flat surface, rough initial surface, three-dimensional complex shape and IC substrate can be polished. Research limitations/implications: The data under various polishing conditions of the MCF float polishing technique helps to clarify the present polishing technique's possible practical applications. As shown in a previous paper, since MCF contains long magnetic clusters, the present polishing technique allows float polishing with large clearance. Therefore, many applications of the MCF float polishing are useful in the polishing fields. Practical implications: The present study indicates the practical application in the polishing. Originality/value: The present technique of MCF float polishing is new in the field of float polishing. In addition, the ordinary float polishing technique having large clearance has not been proposed. Therefore, the present paper is very useful in the polishing field.

3

Flow through a rotating helical pipe with a wide range of the Dean number

Alam M. M., Ota M., Ferdows M., Islamv M. N., Wahiduzzaman M., Yamamoto K.

Archives of Mechanics

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2007

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Vol. 59, nr 6

501-517

EN

THE INCOMPRESSIBLE viscous steady flow through a helical pipe of circular cross-section, rotating at a constant angular velocity about the center of curvature is investigated numerically to examine the combined effects of rotation (Coriolis force), torsion and curvature (centrifugal force) on the flow. The flow depends on the Taylor number Tr =…, the Dean number Dn =…- , the torsion parameter … and the dimensionless curvature of the duct …, where a is the radius of the helical pipe, HT the angular velocity, // the viscosity, v the kinematic viscosity, G the constant pressure gradient along the pipe axis and … - a parameter related to the torsion T and curvature 5, When … > 0, the rotation is in the direction in which the Coriolis force produces the curvature effect. When QT < 0, the rotation is in the direction in which the Coriolis force exhibits an opposite effect to that of curvature. The calculations are carried out for -500 < Tr < 500, 1500 < Dn < 2000 (large Dean number), 0 < (30 < 0.4 and 0 < … < 0.2. The total flux through the duct has a sharp peak at a negative Tr.

4

Determination of naringin and hesperidin in citrus fruit by high-performance liquid chromatography. The antioxidant potential of citrus fruit

Gorinstein S., Huang D., Leontowicz H., Leontowicz M., Yamamoto K., Soliva-Fortuny R., Martin-Belloso O., Martinez-Ayala A. L., Trakhtenberg S.

Acta Chromatographica

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2006

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No. 17

108-124

EN

Naringin and hesperidin in dimethyl sulfoxide extracts of citrus fruit (oranges, red and blond grapefruit, and sweeties – a hybrid of pummelo and blond grapefruit) have been analyzed by high-performance liquid chromatography with a mobile phase prepared from 2% aqueous acetic acid and acetonitrile. The detection wavelength was at 285 nm. Antioxidant assays based on hydrogen atom-transfer reactions (oxygen radical absorbance capacity, ORAC) and on electron transfer (total phenols by use of Folin–Ciocalteu reagent, FCR; trolox-equivalent antioxidant capacity, TEAC; ferric ion-reducing antioxidant power, FRAP; and reaction with 1,1'-diphenyl- 2-picrylhydrazyl, DPPH) were used to compare the antioxidant potential of citrus fruit and their main flavonoids. The three antioxidant assays (FRAP, TEAC, and DPPH) were performed with prolonged duration of the assay time, because all fruit extracts require long reaction times to approach the end point in the scavenging reaction. Lipophilic and hydrophilic fractions from citrus fruit were investigated by the ORAC reaction. Relationships between the main flavonoids, total polyphenols, and antioxidant potential obtained by use of the FRAP, TEAC, and DPPH procedures showed that correlation coefficients are higher for polyphenols than for the main flavonoids (as markers of 100% citrus juices). HPLC is a precise method for obtaining reliable data on the bioactivity of citrus fruit grown under the same geographical and climatic conditions. The bioactivity of citrus fruit studied by use of five different antioxidant assays was in the order sweetie > red grapefruit > blond grapefruit = orange. Hesperidin and naringin are only partially responsible for the overall antioxidant activity of citrus fruit.

5

Evaluation of interlaminar shear stresses in a fiber-reinforced laminated beam by the ifrm theory

Kurashige M., Yamamoto K., Watanabe K.

Applied Mechanics and Engineering

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1998

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Vol. 3, no 4

601-619

EN

By using the linear IFRM theory, interlaminar shear stresses are estimated for a fiber-reinforced laminated beam subjected to a line force. The analysis for this estimation is fully three-dimensional. The beam has three layers. Its core is reinforced in the width direction, whereas its skins in the longitudinal direction. The skins are also assumed to have infinitesimal thickness for the sake of analytical simplicity. In spite of this assumption, inextensibility of the skin layers is valid, since the IFRM theory postulates that the materials are completely inextensible in fiber directions. The analytical results explain very well the observations of delamination shapes and justify applicability of various beam theories to the theoretical analysis of the observations in beam impact tests by use of a line nose impactor. It is also shown that the IFRM theory can explain the observed slight deviation of the delamination from the interface at its early stage.