• Title/Summary/Keyword: 유연핀

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고온압착 건조 처리시 표면처리를 통한 고강도 라이너지 개발

  • 최병수;윤혜정;류정용;신종호;송봉근
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2000.11a
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    • pp.63-63
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    • 2000
  • 저급의 고지 원료를 두께 방향으로 고온 압착을 가하여 건조함으로써 전반적인 종이 물성 을 향상시키는 콘디벨트 건조 방식은 70년대 중반부터 80년대에 이르는 10여년에 걸친 개발 과정을 거쳤으며 90년대에 들어서 핀랜드의 Inkeroinen에 위치한 V alemt- Tarnpella의 연구 소에 최초의 파일로트 설비가 설치되었으며 그 후 1996년에는 핀랜드 ENSO사의 P Pank밟oski 판지공장에 설치됨으로써 세계 최초의 상업생산설비를 이루게 되었다. 기존의 실린더 건조 기술과 비교할 때 콘디벨트 건조방식은 건조속도를 약 5-15배 향상시킬 수 있 으며, 건조 에너지 절감에 큰 효과가 있을 뿐만 아니라 기존의 실린더 건조시 종이가 폭방 향으로 수축되 어 인장 stiffness와 압축 강도 동의 종이 물성 이 저 하되 는 반면 습윤상태 의 섬유를 120도씨이상에서 가열에 의해 리그닌을 연화시킴과 동시에 섬유의 유연성을 증가시켜 준다. 그리고 높은 압력을 가해줌으로써 섬유간의 결합 면적을 증가시키고 건조시 종이의 폭방향의 수축을 감소시켜 인장강도, 내부결합강도, 밀도, 표면평활성, 투기저항성 등 종이의 물성을 대폭 향상시켜주는 혁신적인 제지기술로 인정받고 있으며 국내의 경우 현재 1998년 부터 상업생산을 이루어짐으로써 그 공헌도는 매우 크다고 할 수 있다. 골판지의 주원료가 되는 국산 골판지 고지 (Korean old corrugated container, K KOCC)의 거듭된 재생처리로 인하여 미세분의 함량이 전체 지료의 절반 이상에 달할 뿐만 아니라, 섬유가 각질화와 단섬유화로 인하여 고온압착 건조처리 만으로는 골판지 고지로 생 산된 원지의 강도를 버진펄프로 생산된 원지가 가지는 강도에 준하는 강도로 향상시키는데 한계점을 가지게 된다. 유럽의 제지선진국들은 골판지 원지의 강도를 향상시키는 방편으로 표변에 전분 사이즈 프레스 처리를 도입하였으며 본 연구에서는 고온 압착 건조 처리 설비를 활용한 전분 표면처리의 가능성을 검토하고 골판지 원지의 강도를 향상시키기 위한 표면처리조건을 탐색하였다.

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Development of a High speed Actuator for electric performance testing System of ceramic chips (세라믹칩 전기적 성능검사 시스템을 위한 고속구동 액튜에이터 개발)

  • Bae, Jin-Ho;Kim, Sung-Gaun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.4
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    • pp.1509-1514
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    • 2011
  • The core of IT products, electronic components, especially the MLCC, chip inductors, chip Varistors and so on. In order to test the electrical characteristics of the chip using the Reno-pin contact test method has been used. In current chips, mass production of semiconductor manufacturing processes, high-speed production test for the chip speed up, precision is required. But Vibration displacement is a very short, so in order to overcome these shortcomings, the displacement amplification to design the structure has been actively studied. In this paper, a building structure with a flexible hinge was designed amplification instrument, semiconductor chip industry in the performance test and inspection equipment to measure the electrical characteristics of high speed linear actuators Reno-Pin using system was developed.

Characteristic of Vibration in Windturbine System (풍력발전시스템의 진동특성)

  • Kim, Jung-Su;Lee, Hyoung-Woo;Park, No-Gill;Kim, Young-Duk;Kim, Soo-Yum;Lee, Dong-Hwan
    • Journal of Advanced Marine Engineering and Technology
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    • v.35 no.6
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    • pp.786-795
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    • 2011
  • This paper described the characteristic of vibration in wind turbine system including gearbox housing, gear drive, blade, generator. Especially, in planetary gear set, planet gears are supported by flexible pin. So, in planet gear, to consider not only torsional movement but also lateral movement. And include housing movement, because wind turbine system is supported by mount. To find out the characteristic of vibration, take the excitation source and study campbell diagram in operating range. Results of campbell diagram, resonances are occurred at 81.2HZ, 104.7Hz by 2nd tooth passing frequency. And resonance are also occurred at 264.5HZ, 377Hz, 424.6Hz by 3th tooth passing frequency. From the result, take vibration reduced measures.

Surgical Repair of Rostral Hemimandibular Fractures with Canine Tooth Luxation in a Dog (개에서 견치 탈구를 동반한 앞쪽 하악골 골절의 수술적 정복 1례)

  • Yoon, Hun-Young;Kang, Myung-Gon;Jeong, Soon-Wuk
    • Journal of Veterinary Clinics
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    • v.26 no.4
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    • pp.359-361
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    • 2009
  • A sexually intact female Alaskan Malamute, 5-year-old weighing 25.2 kg presented to the Hangang Animal Hospital, following hit-by-car. On initial presentation, the dog had severe salivation and the right canine tooth luxation. Radiographs revealed fractures of the right rostral hemimandible with the right canine tooth luxation and symphyseal separation. Surgical repair of fractures was performed by use of an interdental wiring technique and external fixation technique that included pins, an acrylic connecting bar, and polymethyl methacrylate bone cement. Post-operative radiographs revealed that bridging callus was well formed over cortices of the fracture area. Pins and an acrylic connecting bar were removed 7 weeks post-operatively. The dog exhibited evidence of normal mastication.

Bending Properties of the Flexible BMNO (Bi2Mg2/3Nb4/3O7) Capacitor Using Graphene Electrode (그래핀 전극을 이용한 유연한 BMNO (Bi2Mg2/3Nb4/3O7) 캐패시터의 굽힘 특성)

  • Song, Hyun-A;Park, Byeong-Ju;Yoon, Soon-Gil
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.25 no.5
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    • pp.387-391
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    • 2012
  • Graphene was fabricated onto Ni/Si substrate using a rapid-thermal pulse CVD and they were transferred onto the Ti/PES flexible substrate. For top electrode applications of the BMNO dielectric films, graphene was patterned using a argon plasma. Through an AFM image and a leakage current density of the BMNO films grown onto various bottom electrodes before and after bending test, BMNO films grown onto the graphene bottom electrode showed no change of the microstructure and the leakage current density after the bend.

E-Machining of Engineering-to-Order Mold Park from e-Catalog (주문자 요구에 유연하게 대응하는 금형 부품의 전자 거래)

  • Mun, Du-Hwan;Jang, Kwang-Sub;Han, Soon-Hung;Kim, Jun-Hwan;Hwang, Ho-Jin
    • The Journal of Society for e-Business Studies
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    • v.12 no.1
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    • pp.1-24
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    • 2007
  • In the mold parts industry, customers typically place orders for order-made parts with some changes to the design specifications of ready-made parts within the extent of the manufacturing capability of the supplier. Being customized for ready-made parts, existing e-Catalog systems cannot support the above trade pattern. To solve this problem, an ETO (engineering-to-order) method is proposed here, enabling the trade of order-made parts in an e-Catalog system by utilizing the design and manufacturing knowledge of the part suppliers. After addressing technological challenges and solutions, we briefly describe application of the ETO method to two types of mold parts - ejector pins and mold bases.

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A Review: Comparison of Fabrication and Characteristics of Flexible ReRAM and Multi-Insulating Graphene Oxide Layer ReRAM (산화 그래핀을 절연층으로 사용한 유연한 ReRAM과 다층 절연층 ReRAM의 제작 방법 및 결과 비교)

  • Kim, Dong-Kyun;Kim, Taeheon;Yoon, Taehwan;Pak, James Jungho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.8
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    • pp.1369-1375
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    • 2016
  • A rapid progress of the next-generation non-volatile memory device has been made in recent years. Metal/insulator/Metal multi-layer structure resistive RAM(ReRAM) has attracted a great deal of attention because it has advantages of simple fabrication, low cost, low power consumption, and low operating voltage. This paper describes the working principle of the ReRAM device, a review of fabrication techniques, and characteristics of flexible ReRAM devices using graphene oxide as an insulating layer and ReRAM devices using multi-layered insulator. The switching characteristics of the above ReRAM devices have been compared. The oxidized graphene could be employed as an insulator of next generation ReRAM devices.

Fabrication and Characterization of Transparent Conductive Film based on Bacterial Cellulose (Bacterial cellulose를 기반으로 하는 투명전도성막의 제조 및 특성평가)

  • Yim, Eun-Chae;Kim, Seong-Jun;Kee, Chang-Doo
    • Korean Chemical Engineering Research
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    • v.51 no.6
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    • pp.766-773
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    • 2013
  • A transparent film was fabricated based on bacterial cellulose (BC), BC has excellent physical strength and stability at high temperature and it is an environmental friendly flexible material. In order to improve the conductivity, silver nanowire (AgNW) and/or graphene were introduced to the BC membrane. The aspect ratio of the AgNW synthesized in this study was 214, with a length of $15{\mu}m$ and width of 70 nm. The higher aspect ratio improved the conductivity by reducing the contact resistance. The thermal and electrical properties of 7 types of films prepared were investigated. Each film was fabricated with rectangular shape ($2mm{\times}2mm{\times}50{\mu}m$). The films were scored with a net shape by a knife, and filled with AgNW and graphene to bestow conductivity. The film filled with AgNW showed favorable electrical characteristics with a thickness of $350{\mu}m$, electron concentration of $1.53{\times}10^{19}$, electron mobility of $6.63{\times}10^5$, and resistivity of 0.28. The film filled with graphene had a thickness of $360{\mu}m$, electron concentration of $7.74{\times}10^{17}$, electron mobility of 0.17, and resistivity of 4.78. The transmittances at 550 nm were 98.1% and 80.9%, respectively. All the films were able to light LEDs bulbs although their brightness differed. A thermal stability test of the BC and PET films at $150{\pm}5^{\circ}C$ showed that the BC film was more stable, whereas the PET film was quickly banded. From these results, it was confirmed that there it is possible to fabricate new transparent conductivity films based on BC.

Gastrointestinal Foreign Bodies in Children -Experiences of 60 Cases in Kangwon, Korea- (소아 위장관 이물 -강원지역 소아 60례-)

  • Lee, Young-Sub;Kang, Kae-Wool;Choi, Won-Kyu
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.4 no.2
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    • pp.148-154
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    • 2001
  • Purpose: Ingested foreign bodies present a common clinical problem. It is well known that most of them pass uninterrupted through the gastrointestinal tract. We evaluated the role of endoscopy and Foley catheter for removal of foreign bodies in the gastrointestinal tract. Methods: We investigated retrospectively 60 cases with foreign bodies in the gastrointestinal tract. They had been treated at Wonju Christian Hospital, Yonsei University of Korea, from January, 1996 through December, 1999. Results: The age of the patients ranged from 7 months to 13 years. Patients under 5 years were 57 cases (97%) and there was no significant difference in sex (M : F=1.07 : 1). 45 cases of the patients had no symptom. The most common foreign bodies were coins (43 cases). The most common location was esophagus (31 cases). The number of foreign body removal using flexible endoscopy and Foley catheter was 22 (36.7%) and 18 (30.0%) cases, respectively. In 18 cases (30.0%), foreign bodies passed spontaneously. Only 1 case (1.7%), curtain pin impaction at ileocecal region, required surgery. Conclusion: Early foreign body removal from esophagus and stomach is recommended to lessen the morbidity and complication. Fluoroscopic foley catheter technique and flexible endoscopy for removal of esophageal foreign bodies in children is safe and effective.

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Evaluation of Variation in Residual Strength of Carbon Fiber Reinforced Plastic Plate with a Hole Subjected to Fatigue Load (피로하중에 의한 홀 노치 탄소섬유강화 복합재의 잔류강도변화 평가)

  • Kim, Sang-Young;Kang, Min-Sung;Koo, Jae-Mean;Seok, Chang-Sung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.34 no.10
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    • pp.1411-1417
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    • 2010
  • CFRP (Carbon Fiber Reinforced Plastic) has received considerable attention in various fields as a structural material, because of its high specific strength, high specific stiffness, excellent design flexibility, favorable chemical properties, etc. Most products consisting of several parts are generally assembled by mechanical joining methods (using rivets, bolts, pins, etc.). Holes must be drilled in the parts to be joined, and the strength of the components subjected to static and fatigue loads caused by stress concentration must be decreased. In this study, we experimentally evaluated the variation in the residual strength of a holenotched CFRP plate subjected to fatigue load. We repeatedly subjected the hole-notched specimen to fatigue load for a certain number of cycles, and then we investigated the residual strength of the hole-notched specimen by performing the fracture test. From the results of the test, we can observe the initiation of a directional crack caused by the applied fatigue load. Further, we observed that the residual strength increases with a decrease in the notch effect due to this crack. It was evaluated that the residual strength increases to a certain level and subsequently decreases. This variation in the residual strength was represented by a simple equation by using a model of the decrease in residual strength for plain plate, which was developed by Reifsnider and a stress redistribution model for hole-notched plate, which was developed by Yip.