• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.975-976
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• 2006

The present paper is a parameter study of zinc flake production using a Simoloyer CM01 horizontal high energy rotary ball mill. The manufactured flakes have a dimension in thickness (t) < $1{\mu}m$ and diameters (d) 5-100 ${\mu}m$, consequently a ratio d/t up to 200. The flake geometry is mainly controlled by the variation of process parameters such as rotary speed of the rotor, ratio of powder/ball charge, load ratio of the system, process temperature, operating model and the quantity of process control agent (PCA). The Zn flakes were characterized by SEM, tap densitometry, laser diffraction and water coverage measurement.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제3B권3호
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• pp.133-138
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• 2003

In this paper, a BLDC motor and its controller are developed for treadmill application. Motor size and structure are restricted in the design stage due to the limited and enclosed space of the treadmill. The shape of the rotor magnet is analyzed using FEM with restricted design conditions. Manufacturing, cost and performance are also considered. A biomechanical analysis of human locomotion with the change of velocity is considered in the design of the controller. For stable operation of the treadmill, current and temperature are to be detected by the DSP controller. The prototype BLDCM and its controller are tested to verify its performances.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.323-326
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• 1999

In this paper, a windmill type ultrasonic motor operated by single-Phase AC electric field was fabricated, and then torque characteristics were investigated. A metal-ceramic composite component was used as the stator\`s vibrator to generate ultrasonic vibrations. The windmill type ultrasonic motors has only three components; a stator element with two wind-mill shape slotted metal endcaps, a rotor and a bearing. In this parer we measured torque, when stator\`s slot was changed Iron 4, 6, 8. Brass metal was pressed with umbrella-type using metal molt then slot of 3 kind was manufactured. The maximum revolution speed was 388(rpm) in the case of a small ultrasonic motor of 11.35 mm diameter, 8 slot and 1.01 mm thickness. The maximum torque of 0.17 mNm was obtained at a speed of 131 rpm.

• 한국분말재료학회지
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• 제30권5호
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• pp.409-414
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• 2023

YSZ (Y₂O₃-stabilized zirconia)-based ceramics have excellent mechanical properties, such as high strength and wear resistance. In the application, YSZ is utilized in the bead mill, a fine-grinding process. YSZ-based parts, such as the rotor and pin, can be easily damaged by continuous application with high rpm in the bead mill process. In that case, adding WC particles improves the tribological and mechanical properties. YSZ-30 vol.% WC composite ceramics are manufactured via hot pressing under different pressures (10/30/60 MPa). The hot-pressed composite ceramics measure the physical properties, such as porosity and bulk density values. In addition, the phase formation of these composite ceramics is analyzed and discussed with those of physical properties. For the increased applied pressure of hot pressing, the tetragonality of YSZ and the crystallinity of WC are enhanced. The mechanical properties indicate an improved tendency with the increase in the applied pressure of hot pressing.

• 펄프종이기술
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• 제48권3호
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• pp.14-22
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• 2016

Pulping is a stage that can change fibrous raw materials into pumpable slurry. Recovered paper can be defibrated to individual fibers by shear stress generated by rotation of a rotor and water. Disintegration of recovered paper is more complicated than that of chemical pulp. When disintegration of recovered paper is poor, screening and cleaning efficiency will be worse and properties of paper will also be deteriorated. Therefore, pulping is an important treatment for improvement of availability of recovered paper and process runnability. In this study, degrees of disintegration of KOCC obtained from a linerboard mill was analyzed with a pilot-scale screen. Flake removal of KOCC slurry was performed by a pilot screen. Simple pumping action gave a positive effect on disintegration of KOCC. After pumping for 10 minutes, paper strength increased without the change of water retention value and fibrillation of KOCC slurry. This phenomena can be explained by modification of hornified surface of KOCC fibers by shear stress generated by pumping. Consequently, disintegration efficiency of KOCC can be enhanced by control of retention time at pulper or an agitation power at chests of papermaking process.