자가치아 뼈 이식재의 유용성에 관한 임상적 연구

한민우,이정근,Han, Min Woo,Lee, Jeong Keun 대한악안면성형재건외과학회 2013 Maxillofacial Plastic Reconstructive Surgery Vol.35 No.4

Purpose: This study is to evaluate the efficacy of the autogenous tooth bone graft material, clinically and radiologically, as related to implant installation. Methods: In oral and maxillofacial surgery department of Ajou University Hospital, guided bone regeneration (GBR), implant placement combined with GBR, sinus graft, implant placement combined with sinus graft, and defect filling were performed in 46 patients, using autogenous tooth bone. Among these, 66 implants were inserted with autogenous tooth bone. Implant stability quotient (ISQ) was measured by Osstell Mentor (Integration Diagnostics, Goteborg, Sweden) on 39 implants on the operation date and 4 months later, and on 21 implants 9months on the average at the final setting of restoration. Twenty-eight implants with GBR and sinus graft (GBR group: n=14, sinus graft group: n=14) were evaluated radiologically to measure the resorption of grafted autogenous tooth bone after loading. Results: The average initial stabilization of the installed implants was 67 ISQ, and the average secondary stabilization at 4 months later was 76. The average bone loss of GBR group as measured 8.0 months after application of prosthesis loading was 0.29 mm and the average bone loss of the sinus graft group as measured 7.6 months after application of prosthesis loading was 0.66 mm, respectively. In the histological assessment, formation of the new bone and continuous trabecular bone pattern was identified around autogenous tooth bone. Conclusion: Based on these results, we concluded that autogenous tooth bone is an excellent bone graft material that can substitute the autogenous bone.

섬유 강화 지능형 연성 복합재 구동기의 재료구성에 따른 거동특성 평가

한민우(Min-Woo Han),김형일(Hyung-Il Kim),송성혁(Sung-Hyuk Song),안성훈(Sung-Hoon Ahn) 대한기계학회 2017 大韓機械學會論文集A Vol.41 No.2

섬유강화 고분자 복합재료는 섬유 형태의 강화제와 고분자 형태의 기지재료가 결합된 형태로 이는 무게 대비 고강도 및 고강성의 구조물 제작에 용이하다. 본 연구에서는 형상기억합금 와이어가 삽입된 섬유 강화 지능형 연성 복합재 구동기를 제작, 이의 재료 구성에 따른 거동 특성을 평가 하고자 한다. 구동기는 형상기억합금이 포함된 구동층과 일반 구조층으로 구성되어 한 층씩 적층되는 방식으로 제작되며 재료 구성에 따른 거동 특성을 살펴보기 위하여 일반 구조층으로 사용된 유리섬유 직물의 적층 수, 기지재료의 종류를 달리한 뒤 구동 특성을 살펴보았다. 또한, 구동 시에 요구되는 인가 전류의 양을 달리하여 최대 구동각과 최대 구동각에 도달하는 구동 시간을 측정하였다. Fiber-reinforced polymer composites, which are made by combining a continuous fiber that acts as reinforcement and a homogeneous polymeric material that acts as a host, are engineering materials with high strength and stiffness and a lightweight structure. In this study, a shape memory alloy(SMA) reinforced composite actuator is presented. This actuator is used to generate large deformations in single lightweight structures and can be used in applications requiring a high degree of adaptability to various external conditions. The proposed actuator consists of numerous individual laminas of the glass-fiber fabric that are embedded in a polymeric matrix. To characterize its deformation behavior, the composition of the actuator was changed by changing the matrix material and the number of the glass-fiber fabric layers. In addition, current of various magnitudes were applied to each actuator to study the effect of the heating of SMA wires on applying current.

Design and Fabrication of Smart Textile based on Shape Memory Alloy

Min-Woo Han(한민우),Hyung-Il Kim(김형일),Sung-Hyuk Song(송성혁),Sung-Hoon Ahn(안성훈) (사)한국CDE학회 2015 한국 CAD/CAM 학회 학술발표회 논문집 Vol.2015 No.동계

연구노트 : Pediocin 처리가 생면의 저장 중 PH와 미생물에 미치는 영향

한민우 ( Min Woo Han ),박기재 ( Kee Jai Park ),정승원 ( Seong Weon Jeong ),김석중 ( Seok Joong Kim ),윤광섭 ( Kwang Sup Youn ) 한국식품저장유통학회 ( 구 한국농산물저장유통학회 ) 2007 한국식품저장유통학회지 Vol.14 No.3

습식분쇄하여 분무건조한 초미세 분말 칼슘의 품질특성

한민우(Min-Woo Han),윤광섭(Kwang-Sup Youn) 한국식품과학회 2009 한국식품과학회지 Vol.41 No.6

해조칼슘을 습식분쇄한 초미세액상칼슘을 분무건조하여 부형제 종류에 따른 분말칼슘의 품질특성을 알아보고자 gum arabic, cyclodextrin, Na-caseinate를 첨가하여 품질특성을 비교하였다. 분무건조한 초미세분말칼슘의 수분함량은 2% 내외의 안정한 분말을 얻을 수 있었고, 색도는 원료인 해조칼슘보다 L값은 높았으며, b값은 감소하는 것으로 나타났다. 입자크기는 당류의 부형제 첨가로 초미세 크기로 분쇄되는 것을 확인할 수 있었으며, gum arabic을 첨가하여 제조한 초미세액상칼슘을 분무건조한 분말이 식초와 pH에 대한 용해도에서 가장 우수한 것으로 나타났다. 칼슘함량은 해조칼슘분말이 28%의 칼슘함량을 나타내었고, 부형제를 달리하여 제조한 초미세액상칼슘을 분무건조한 분말은 27% 내외로 비슷한 칼슘함량을 나타내어, 습식분쇄나 분무건조 공정에서 칼슘의 손실은 없는 것으로 나타났다. 흡습에 대한 안정성 실험에서는 해조칼슘분말이 흡습에 안정하였으며, gum arabic을 첨가하여 분무건조한 분말이 흡습이 많이 발생하였다. 전자주사 현미경 관찰을 통하여 습식분쇄로 입자크기가 작아지는 것을 확인할 수 있었고, gum arabic을 사용하여 얻은 초미세칼슘분말이 단백질계나 사용하지 않았을 때보다 더 균일한 입자분포를 보였다. 따라서 습식분쇄한 초미세액상칼슘을 분말화하여 용해성등 품질특성이 개선됨을 확인하였으며 습식분쇄기술과 분무건조법을 식품가공기술로 활용할 수 있는 가능성을 확보하였다. Liquid microparticulated seaweed calcium was manufactured via a wet grinding process. Thereafter, different forming agents such as cyclodextrin, gum arabic, and Na-caseinate were added to the liquid calcium, which was then spray-dried to investigate the quality of the powdered calcium treatments. The moisture contents of samples were approximately 2%. It was also determined that the different kinds of forming agents did not affect the spray drying efficiency. In addition, calcium solubility was the highest in a solution of pH 2. In buffer solution and vinegar, the powdered calcium made with gum arabic showed the highest solubility among the treatments. The calcium contents of all the powdered microparticulate seaweed calcium samples were about 28%, and calcium content was not affected by the forming agents. The spray-dried calcium powder made by spray drying with gum arabic had the highest water vapor uptake, whereas the seaweed calcium was stable in terms of water adsorption. The results of SEM observations indicated that a portion of the spray-dried calcium powders were in nano-scale after wet-grinding. Among the treatments, the use of saccharides as a forming agent resulted in the most uniform particle distribution after spray-drying.

섬유 강화 지능형 연성 복합재 구동기의 재료구성에 따른 거동특성 평가

한민우(Min-Woo Han),김형일(Hyung-Il Kim),송성혁(Sung-Hyuk Song),안성훈(Sung-Hoon Ahn) 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.2015 No.11

The fiber-reinforced polymer (FRP) composites, which are made by combining a continuous fiber as a reinforcement and a homogeneous polymer material as a host, are known as a engineering materials to improve their strength and stiffness with lightweight structure. In this study, the shape memory alloy (SMA) reinforced composite actuator is described to generate a large deformation in a lightweight single structure which can be used in applications requiring a high degree of adaptability to the various external conditions. The proposed actuator consists of a multi-ply composed of individual lamina by embedding in a polymer matrix. To characterize its deformation behavior, the composition of the actuator was changed in terms of the matrix material, and the volume fraction of glass fiber fabric. Also, to study on the effect of heating SMA wires by applying current, different magnitudes of current were applied to each actuators.

직조 형태의 지능형 연성 복합재료를 이용한 쉘 구동기의 제작

한민우(Min-Woo Han),송성혁(Sung-Hyuk Song),추원식(Won-Shik Chu),이경태(Kyung-Tae Lee),이재원(Daniel Lee),안성훈(Sung-Hoon Ahn) Korean Society for Precision Engineering 2013 한국정밀공학회지 Vol.30 No.1

Smart material such as SMA (Shape Memory Alloy) has been studied in various ways because it can perform continuous, flexible, and complex actuation in simple structure. Smart soft composite (SSC) was developed to achieve large deformation of smart material. In this paper, a shell actuator using woven type SSC was developed to enhance stiffness of the structure while keeping its deformation capacity. The fabricated actuator consisted of a flexible polymer and woven structure which contains SMA wires and glass fibers. The actuator showed various actuation motions by controlling a pattern of applied electricity because the SMA wires are embedded in the structure as fibers. To verify the actuation ability, we measured its maximum end-edge bending angle, twisting angle, and actuating force, which were 103°, 10°, and 0.15 N, respectively.

초미세습식분쇄공정의 공정변수에 따른 해조칼슘의 입자크기 분석

한민우 ( Min Woo Han ),윤광섭 ( Kwang Sup Youn ) 한국산업식품공학회 2009 산업 식품공학 Vol.13 No.4

습식분쇄의 최적조건을 얻고자 부형제 종류, 농도, 습식분쇄시 rotor speed, bead size, feed rate, 분쇄회수를 달리하여 분쇄한 결과, 부형제로는 gum arabic을 사용하여 5%의 농도로 첨가할 때 가장 좋은 분쇄효과를 나타내었다. Rotor speed를 달리하여 습식분쇄한 결과, rotor speed가 증가할수록 좋은 결과를 나타내어 4,000 rpm에서 가장 우수한 것으로 나타났다. 원료와 직접 부딪혀 분쇄를 하게 되는 bead는 0.4 mm의 크기를 사용하였을 때 가장 작은 사이즈로 분쇄되는 것으로 나타났다. 분쇄가 이루어지는 chamber내에 원료를 공급하는 비율에 따른 결과에서는 40 L/h 의 속도로 공급했을 때 가장 작은 입도분포를 보였다. 분쇄회수에 따른 영향은 횟수에 따라서는 8회 이상으로 분쇄하였을때 0.6 μm이하의 입도분포가 90% 이상으로 나타나 10회를 분쇄하였을때 가장 좋은 효과를 나타내었다. 연속운전과 비연속운전의 비교에서는 연속운전이 더 효율적이었으며 부형제 종류에 따른 영향은 gum arabic을 첨가하여 분쇄하였을때 가장 우수한 결과를 나타내었다. 따라서 적절한 농도와 종류의 부형제 사용과 rotor speed, bead size, feed rate, 용매와의 혼합비의 최적공정을 수립한 습식분쇄기술로 초미세액상칼슘의 제조가 가능하였고, 습식분쇄기술을 식품가공기술로 활용할 수 있는 가능성을 확보하였다. The main objective of this study was to establish optimum condition of wet-grinding process for manufacturing microparticulated seaweed calcium. Process parameters such as concentration of forming agent, rotor speed, bead size, feed rate, and grinding time were adapted during wet-grinding of seaweed calcium. The particle size range of the raw seaweed calcium was 10-20 μm. The calcium particles were reduced to under 1 μm as nano scale after grinding. Gum arabic was suitable for forming agent and 5%(w/v) concentration was the most effective in grinding efficiency. A wet-grinding process operated at 4,000 rpm rotor speed, 0,4 mm bead size, and 0.4 L/hr feeding rate, respectively, produced less than 600 mm(>>90%)-sized particles. In batch systems, 8 cycles of grinding showed higher efficiency, but 20 min of grinding time in continuous processing was more efficient to reduce particle size than the batch processing. Based on the result, the optimum conditions of the wet grinding process were established: operation time of 20 minutes, rotor speed of 4,000 rpm, bead size of 0.4 mm, feed rate of 40 mL/min and 30% mixing ration with water. The size of the resulting ultra fine calcium particles ranged between 40 and 660 mm.

지능재료 기반 소프트 구동기: 형상기억합금과 유전탄성체의 활용

한민우(Min-Woo Han) Korean Society for Precision Engineering 2019 한국정밀공학회 학술발표대회 논문집 Vol.2019 No.5월

Fabrication of Miniature High-Speed Actuator Capable of Biomimetic Flapping Motions

Min-Sik Kim(김민식),Sung-Hyuk Song(송성혁),Min-Woo Han(한민우),Won-Shik Chu(추원식),Sung-Hoon Ahn(안성훈) Korean Society for Precision Engineering 2017 한국정밀공학회지 Vol.34 No.9

Beyond conventional military products, technologies in the defense industry sectors around the globe are integrated and fused with newly emerging technologies such as three-dimensional printing (3DP) and smart material fabrication. Acknowledging these trends, this study proposes a miniature high-speed actuator whose fabrication process entails 3DP, smart materials, and shape memory alloy. The manufactured actuator is 25 mm long and 5 mm wide in and weighs 2.5 g, having the optimal frequency in the range of 35-40 Hz. Force and deformation measurement were also conducted, resulting in the lift force of 0.18 N per second with a bending deformation of 5 mm.