• Journal of the Korean Ceramic Society
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• v.35 no.2
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• pp.172-179
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• 1998

Valve lifter namely tappet is supported by lifter hole which is located upper side of camshaft in cylinder block transforms rotatic mvement of camshaft into linear movement and helps to open and shut the en-gine valve as an engine parts. The face of valve lifter which is continuously contacting with camshaft brings about abnormal wears such as unfair wear and early wear because it is severely loaded in the valve train system. These wears act as a defect like over-clearance and cause imperfect combustion of fuel during the valve lifting in the combustion chamber. Consequently this imperfect combustion makes the engine out-put decrease and has cause on air pollution. To prevent these wears therefore The valve lifter cast in me-tal developed into SiC ceramics valve lifter which has an excellence in wear and impact resistance As a results the optimum process conditions like injection condition mixture ratio and debonding process could be established. After sintering fine-sinered dual microstructure in which prior ${\alpha}$-SiC matches well with new SiC(${\beta}$-SiC) produced by reaction among the ${\alpha}$-SiC carbon and silicon was obtained. Based on the study it is verified that mechanical properties of SiC valve lifter are excellent in Vickers hardness 1100-1200 bending strength (300-350 Pa) fracture toughness(1.5-1.7 Mpa$.$m1/2) Through engine dynamo test-ing SiC valve lifter and metal valve lifter are examined and compared into abnormal phenomena such as early fracture unfair and early wear. It is hoped that this research will serve as an important springboard for the future study of heavy duty diesel engine parts developed by ceramics which has a good wear resis-tance relaibility and lightability.

• Journal of the Korea Furniture Society
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• v.21 no.3
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• pp.253-260
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• 2010

The drop handle in the Chosun-Dynasty played a role lifting up the cabinet and box which was attached to and besides this had the decoration function. The scope of this study should include the drop handles from the $18^{th}$ century up to now by investigating and analyzing their definition & function and furthermore the types of their designs. The object of the study was the drop handle having 2 golden fixing parts which are definitive difference from ring or loop, and the design typology of drop handle was concentrated on the handle part, and it can be classified in two types. The one is the figuration of bow, bat, bamboo, fish and bird and so on from the motive of nature on the handle part, and the other one is the drop handle of the simple ㄷ-shape, the temple-symbol shape or geometrical forms. According to the analysis of relics & literature from the past it was found that there were more quantitative nature-motive figurations than the geometrical forms. The nature-motive figurations were again classified in box-, bat-, cloud- bamboo-, fish- and bird-type, and the geometrical forms in ㄷ-shape, the temple-symbol shape and others. The cases applied to furniture are roughly divided into the front-attached type and the side-attached type. In comparison of the drop handle in the Chosun-Dynasty with that of modern times, ㄷ-shape and bow-type keep the long tradition of the drop handles despite of the constructive change partly. Ring-type is similar to the just ring or loop of the part and drop handle with one golden fixing part, while the knob-type shows almost same forms in the past as well as in the modern times. Which type among handles in the modern times has little connection with the past is the reclaimed type, and it was showed in the Chosun-Dynasty and also is showed up to now identically that the man-made hole on the front side of the drawer for the function as handle.