• Title/Summary/Keyword: Dressing Resistance

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Studies on Morphological and Physical Characteristics of Wheat and Barley Culms under Different Cultural Conditions 1. Effects of Top-Dressing Time of Nitrogen on Morphological and Physical Characteristics of Barley Culms (재배조건에 따른 맥간의 형태적 및 생리적 특성변화에 관한 연구 I. 질소추비시기가 맥간의 형태적 및 생리적특성에 미치는 영향)

  • Hong-Suk Lee;Chang-Hwan Cho
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.14
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    • pp.117-121
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    • 1973
  • This experiment was conducted to study the effects of nitrogen top-dressed at the different growth stages on the morphological and physical characteristics of barley culm. The results obtained are summarized as follows: 1. By top-dressing of nitrogen in March, each internode length from the third to the fifth internode was shortened, and total fresh weight of the top, dry weight per unit culm, inside or outside culm diameter and thickness of culm were increased. Therefore these characteristics related to lodging indicated the beneficial changes for lodging resistance by top-dressing of nitrogen in March. 2. Both weight of culm at breaking and bending moment of culm at breaking, expressing lodging resistance of culm, were increased in the plots of nitrogen top-dressed in March. Accordingly lodging resistance became higher by top-dressing of nitrogen in March. 3. Both section modulus and secondary moment of inertia, expressing bending stiffness of culm, were increased by top-dressing of nitrogen in March. Accordingly lodging index, expressing comprehensive lodging resistance, became low by top-dressing of nitrogen in March. 4. Both spike weight and grain yield were increased by top-dressing of nitrogen in March. Consequently we came to the conclusion that the suitable top-dressing time of nitrogen was in March.

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Development of ELID Monitoring System and its Application to ELID Grinding of Structural Ceramics (ELID 연삭 모니터링 시스템의 개발과 구조 세라믹스 적용 사례)

  • Kwak, Tae-Soo;Kim, Gyung-Nyun;Kwak, Ihn-Sil
    • Journal of the Korean Society for Precision Engineering
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    • v.30 no.12
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    • pp.1245-1251
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    • 2013
  • This study has focused on development of ELID monitoring system and its application to ELID grinding of structural ceramics. ELID monitoring system was consisted of grinding equipment, ELID power supply, grinding wheel, electrode and monitoring program. It can give a real time data to check spindle grinding resistance, wheel revolution, dressing current and voltage in ELID grinding process. The performance of developed system was evaluated by applying to grinding of structural ceramics, silicon carbide and alumina. As the results of experiments, monitored data for spindle resistance and ELID dressing current was useful to check steady-state ELID grinding process. From the comparison of spindle resistance between ELID grinding and conventional grinding process according to change of depth of cut, it could be confirmed that the spindle resistance in ELID grinding was lower than conventional grinding process.

Ground Surface Control by the Surface-Shaping System (표면 가공법을 이용한 연삭 표면 제어)

  • 최우석
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1997.10a
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    • pp.219-224
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    • 1997
  • In surface grinding, the contact between the grinding wheel and the workpiece introduces heat and resistance, which restrict the self-dressing of the grits and result in burrs and cracks on the workpiece. Therefore, before or during th grinding wheel for more accurate performance. In order to determine the dressing time monitoring method of grinding wheel in surface grinding, a three-dimensional computer simulation of the grinding operation has been attempted based on the contact mechanism and surface-shaping system between the grinding wheel and the workpiece. The optimal dressing time is determined based on the amount of the grain wear and work surface roughness.

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A study on the dressing time monitoring method of grinding wheel in surface grinding (연삭가공시 연삭숫돌의 드레싱 시기 검출 방법에 관한 연구)

    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.7 no.1
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    • pp.112-118
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    • 1998
  • In surface grinding, the contact between the grinding wheel and workpiece introduce heat and resistance, which restrict the self-dressing of the grits and result in burrs and cracks on the workpiece. Therefore, before or during the grinding operation, it is necessary to self-dress the grinding wheel for more accurate performance. In order to determine the dressing time monitoring method of grinding wheel in surface grinding, a three-dimensional computer simulation of the grinding operation has been attempted based on the contact mechanism and surface-shaping system between the grinding wheel and the workpiece. The optimal dressing time is determined based on the grain wear and work surface roughness.

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A Study on Ultra-precision Lapping of Ceramics with In-Process Electrolytic Dressing (연속 전해드레싱을 적용한 세라믹재의 초정밀 래핑에 관한 연구)

  • 이은상
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.9 no.5
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    • pp.34-39
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    • 2000
  • Application of ceramics has grown considerably due to significant improvement in their mechanical properties such as light weight, chemical stability and superior wear resistance. Despite these character, the use of ceramics has not increased because of poor machinability. The method of using of super-abrasives metal bond wheel was proposed. But it is difficult that super-abrasives metal bond wheel can be dressed. Recently, the technology of in-process electrolytic dressing is developed to solve this problem. If this method is applied, loading and glazing are disappeared apparently. The aim of this study is to determine the machining characteristics in terms of lapping wheel speed, machining time, pressurized weight to the workpiece and peak current using in-process electrolytic dressing applied to the CIB-diamond lapping wheel to achieve ultra-precision lapping machining technique.

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Manufacture of Lapping Wheel for Electrolytic Dressing and Evaluation of Electrolytic Characteristics (연속 전해드레싱용 래핑지석의 제작 및 전해 특성 평가)

  • 최재영;이은상;송지복
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.11a
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    • pp.914-917
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    • 2000
  • Application of ceramics, carbide, ferrite has grown considerably due to significant improvement in their mechanical properties such as light weight, chemical stability , super wear resistance and electronical. Despite these character, the me of advanced material has not increased because of poor machinability. The method of using of metal bond wheel was proposed. But it is difficult that metal bond wheel can be dressed. Recently, the technology of in-process electrolytic dressing is developed to solve this problem. This method need wheel for electrolytic dressing, power supply and electrolyte. But development of wheel for electrolytic dressing is the most need. The aim of this study is development of wheel for electrolytic and appraisement of CIB-diamond lapping wheel

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Development of lapping wheel for Electrolytic Dressing and evaluation of performance (전해 드레싱용 래핑지석의 개발 및 성능평가)

  • 송지복;이은상;최재영
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.05a
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    • pp.858-861
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    • 2000
  • Application of ceramics, carbide, ferrite has grown considerably due to significant improvement in their mechanical properties such as light weight chemical stability super wear resistance and electronical. Despite these character, the use of hi-tech material has not increased because of poor machinability. The method of using of metal bond wheel was proposed. But it is difficult that metal bond wheel can be dressed. Recently, the technology of in-process electrolytic dressing is developed to solve this problem. This method need wheel for electrolytic dressing, power supply and electrolyte. But development of wheel for electrolytic dressing is the most need. The aim of this study is development of wheel for electrolytic and appraisement of CIB-diamond lapping wheel

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A Study on the Development of In-Processor Dressing Lapping Wheel and its Evaluation of Machining Characteristics (연속 전해드레싱용 래핑숫돌 개발 및 성능평가)

  • Choe, Jae-Yeong;Lee, Eun-Sang;Song, Ji-Bok
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.11
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    • pp.132-137
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    • 2001
  • Application of ceramics, carbide, ferrite has grown considerably due to their mechanical properties such as high degree hardness, chemical stability, super wear resistance. Despite these characters, the use of advanced material has not increased because of poor machinability. The application of metal bonded wheel was proposed. But it is difficult that metal bond wheel can be dressed. Recently, to solve this problem, the technology of in-process electrolytic dressing is developed. This method need wheel for electrolytic dressing, power supply and electrolyte. The aim of this study is development of CIB-D wheel for electrolytic and its evaluation of electrolytic characteristics, and achieve ultra-precision lapping of carbide, optic glass.

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