• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.26 no.2
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• pp.199-204
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• 2017

In this study, analytical methods for designing a torque arm pin and elastomeric bushings of a conventional-type three-point-suspension gearbox of a wind turbine are investigated. The design loads for the torque arm were derived by considering the effects of the transmitted torque and self-weight of the gearbox. Based on the design loads, design methods for the torque arm pin and elastomeric bushings were introduced in the terms of material and size selection. Finally, a small-scale conventional-type gearbox was designed by applying the derived design methods. This study is an elementary and analytical study for the design of the torque arm pin and elastomeric bushings. It is necessary to verify and supplement the results further through extensive experimentation.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.08a
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• pp.21-28
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• 2003

Recently, instead of a matched die forming method requiring a high cost and long deliverly ten a multi-point dieless forming method using a pair of matrix type punch array as flexible dies has been developed. As this multi-point dieless forming method has some disadvantage of difficulty in precise punch control and high-cost of equipment, a new concept of multi-point dieless forming method combined with elastomer forming was suggested in this study. For optimal selection of elastomers, compression tests of rubbers, polyethylene and foams were carried out together with FEM analysis of the deformation behavior during sheet forming process using a rigid punch and elastomers. Compressive strain was concentrated on the upper central area of the elastomer under the punch, and the rubber exhibited higher concentration of the compressive strain than foams. Two-dimensional curved surface was formed successfully by the multi-point elasto-dieless forming method using an optimal combination of a rubber and foam.

• Proceeding of EDISON Challenge
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• 2014.03a
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• pp.263-274
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• 2014

펩타이드 중합체의 이차 구조는 화학적, 생물학적 기능을 갖는 단백질 삼차 구조를 결정하는 중요한 구성요소이다. 이러한 단백질의 이차구조에 대한 정보는 치매, 광우병과 같은 단백질 응집관련 질병에서 응집유발 단백질의 형성과정 및 안정도와 밀접한 연관이 있다. 본 연구는 폴리알라닌을 모델 펩타이드로 선택하여, 이들의 가능한 7가지 이차구조들에 대한 구조적, 열역학적 특성을 계산화학방법을 통해 비교 분석하였다. 우선 기체상에서 7가지 구조들의 구조최적화를 통해 상대적 안정도를 비교하였고, 나아가 EDISON의 용매화 자유 에너지의 열역학적 계산방법을 통해 수용액상에서의 상대적인 안정도와 그 원인을 비교, 분석하였다. 특히, 기체상에서와 수용액상애서 폴리알라닌 이차구조들의 상대적 안정도가 바뀌는 원인에 대해, 폴리알라닌의 구조적 특징과 수소결합과의 상관관계를 통해 규명하였다. 본 연구에서 밝힌 단백질 이차 구조의 상대적 안정도 및 물과의 상관관계에 미치는 구조적, 열역학적 원인은 응집 유발 단백질에서 제시된 특정 이차 구조의 선택적 안정성에 대한 근거를 제시하며, 그 기작을 이해하는 중요한 단서를 제공한다.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10b
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• pp.183-184
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• 2003

Poly(lactic acid) (PLA) is a highly versatile, biodegradable, aliphatic polyester derived from 100% renewable resources, such as corn and sugar beets. Because of the degradation mechanism, PLA is ideally suited for many applications in the environment where recovery of the product is not practical, such as agricultural mulch films and bags. Composting of post consumer PLA items is also a viable solution for many PLA products. (omitted)

• Journal of the Korean Chemical Society
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• v.31 no.1
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• pp.98-101
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• 1987

A new spiro-ortho carbonate containing bulky side group, 3,9-di-(9,10-dihydro-9,10-ethanoanthracenyl)-1,5,7,11-tetraoxaspiro-5,5-undecane 4 was prepared and polymerized with BF3${\cdot}$etherate as initiator. Densities of monomer and polymer were measured using dilatometer and it was demonstrated that the bicyclic monomer 4 underwent expansion on polymerization.

• 유공압시스템학회:학술대회논문집
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• 2010.06a
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• pp.99-104
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• 2010

Nonlinear seal friction in pneumatic cylinders can impede the performance of pneumatic systems designed for high precision positioning with favorable high speed actuation. The behaviour of an elastomeric piston seal in high speed pneumatic cylinders is analysed by nonlinear finite element analysis using ABAQUS. The contact pressures, stress and strain distributions and frictional forces of the piston seal are simulated with variation of interference fits, supply pressures, friction coefficients and piston rod velocities. The nonlinear finite element model of the piston seal is used to predict deformation of a seal, friction force and contact pressure distributions.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.1
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• pp.83-85
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• 2000

The purpose of this study is to evaluate the effect of $HTR^{TM}$ (hard tissue replacement, Bioplant Inc, U.S.A) polymer on short-term healing as a grafting material for alveolar ridge augmentation. A 48-year-old female presented insufficient bone height and width for the placement of implants. $HTR^{TM}$ polymer was used for ridge augmentation. Bone biopsy was harvested 8 months after the ridge augmentation procedure. $HTR^{TM}$ polymer displayed rapid bone regeneration and mature lamellar and trabecular bone redevelopment. Clinical and histologic observation from the treatment of the patient presented suggest that $HTR^{TM}$ polymer seems to be a appropriate material for alveolar ridge augmentation.

• Journal of the Korean Chemical Society
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• v.53 no.3
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• pp.335-339
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• 2009

Polydimethylsiloxane (PDMS) with methacrylate endgroup is used as contact lens material with elasticity and high oxygen permeability. PDMS prepolymer with methacrylate endgroup was prepared by reacting PDMS (polydimethylsiloxane) with HEMA (2-hydroxyethyl methacrylate). The HEMA-substituted PDMS prepolymer was then copolymerized using AIBN (azobisisobutyronitrile) with BMA (butyl methacrylate; to increase elasticity and flexibility). The water content, oxygen permeability, and visible-ray transmissibility of the resulting polymer were measured to be 23%, 83% and Dk/t > 50, indicating that the copolymer can be used as a good contact lens material.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.495-497
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• 2017

Thermoplastic propellants using thermoplastic elastomer binders show moderate performance and mechanical properties compared to thermoset propellants, but these propellants are widely used in a variety of fields due to low cost of raw materials, simple manufacturing process and stable handling process. In order to utilize thermoplastic solid propellants in various fields, we will study properties depending on the content of oxidants, metal fuels and additives.

• YAKHAK HOEJI
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• v.54 no.5
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• pp.334-340
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• 2010

We investigated whether poly-L-histidine (PLH) significantly affect mucin release from cultured airway epithelial cells. Confluent primary hamster tracheal surface epithelial (HTSE) cells were metabolically radiolabeled with $^$^3H$$glucosamine for 24 hr and chased for 30 min in the presence of PLH to assess the effect on $^3H$-mucin release. PLH 9,850 and PLH 6,700 specifically inhibit mucin release from airway goblet cells without significant cytotoxicity. This finding suggests that poly-L-histidine might function as an airway mucoregulative agent.