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Air Jet Spinning 방법으로 제조한 Nylon6 나노 섬유의 결합 특성에 관한 연구
오이슬(Yi Seul Oh),김철인(Chul In Kim),김종우(Jong Woo Kim),선민영(Min Young Sun),김연직(Yon Jig Kim),임재규(Jae Kyoo Lim) 대한기계학회 2013 대한기계학회 춘추학술대회 Vol.2013 No.12
Nano fiber mat which will be used for artificial skin, filter, scaffold of tissue engineering, etc. is porous and must be manufactured for superior mechanical strength. Electrospinning method which is mainly used as a manufacturing method of nanofiber has weaknesses of low production speed and low mechanical characteristics, so method of Air Jet Spinning that has recently been studied overcome this weakness. Therefore, this study made solution of 5, 10, 14, 18, 22 wt% with Nylon6 and Formic acid and made polymer fiber with nano diameter with method of Air Jet Spinning. And then, effects of solution condition for morphologic shape and average diameter were investigated and chemical combination and mechanical characteristics were examined. As the result, method of Air Jet Spinning made lots of effects on chain structure of Nylon6. Unlike the electrospinning producing quasi-stable form of gamma type, Nylon6 manufactured by method of Air Jet Spinning has a structure of thermodynamically stable alpha form and mechanical characteristics of Nylon6 mat were also improved.
박이슬,오정재,김규선,박종섭,Park. Yi Seul,Oh. Jeong Jae,Kim. Kyu Sun,Park. Jong Sup 한국방재학회 2012 한국방재학회논문집 Vol.12 No.1
본 논문에서는 비탄성 영역 내 비지지 길이가 존재하는 I형보의 하중고 효과를 고려한 비탄성 횡-비틀림 좌굴강도에 대한 연구를 수행하였다. 하중조건으로는 집중하중과 등분포하중을 적용시켰으며, 비선형 횡-비틀림 좌굴 해석을 위해 잔류응력 및 초기변형을 고려하였다. Pi와 Trahair(1995)가 고려한 단순직선분포를 잔류응력으로 가정하였으며, 국내 I형강 표준 치수 허용치(현대제철, 2006)에 근거하여 부재 길이의 0.1%를 초기 최대 횡변위로 적용하여 초기제작오차로 고려하였다. 새롭게 제안된 모멘트구배계수식은 유한요소해석결과와 매우 유사한 값을 나타내고 있으며, 제안식은 하중고 효과를 고려한 비선형 횡-비틀림 좌굴강도 산정뿐만 아니라 휨부재 극한강도 산정에도 크게 기여할 것이다. This paper investigates inelastic lateral-torsional buckling strengths of I-beams with load height effects. The combined effects of residual stresses and geometrical imperfection on inelastic lateral-torsional buckling of beams are considered. The distribution of the residual stress in the cross-section is same as shown in Pi and Trahair(1995). The initial imperfection of the beam is set by a central displacement equal to 0.1% of the unbraced length of the beam. New moment gradient factors for load height effect of inelastic beams are very similar to the results from finite element analyses. The proposed equations will greatly contribute to calculate the inelastic lateral torsional buckling strengths with load height effect.
탄소섬유강화 폴리카보네이트의 탄소섬유 함유량에 따른 파괴인성에 관한 연구
김진호(Kim jin ho),오이슬(Oh yi seul),김상범(Kim sang beom),김철인(Kim chul in),임재규(Lim jae kyoo) 대한기계학회 2012 대한기계학회 춘추학술대회 Vol.2012 No.11
In this study, the fracture toughness and the properties of microscopic structure of CFRP produced by injection molding was investigated by universal testing instrument and SEM in the rate of carbon fiber quantity and the weld line. we can obtain each fracture characteristic by performing the strength evaluation of polymer composite material according as carbon fiber ratio of carbon fiber reinforced polycarbonate and weld line.
슈반세포와 골수간엽줄기세포의 공배양이 골수간엽줄기세포의 분화와 증식에 미치는 영향(2)
김초민 ( Cho Min Kim ),김순희 ( Soon Hee Kim ),송이슬 ( Yi Seul Song ),정수현 ( Su Hyun Jung ),박종학 ( Jong Hak Park ),오재민 ( Jae Min Oh ),이동원 ( Dong Won Lee ),유일수 ( Il Sou Yoo ),이종문 ( John M Rhee ),강길선 ( Gil Son Kh 한국조직공학·재생의학회 2009 조직공학과 재생의학 Vol.6 No.4
Schwann cell(SC) play an important role as they are the source of different trophic substances and present a great neurotrophic activity. Bone marrow stromal cells(BMSCs) contain mesenchymal stem cell and progenitor cells. BMSCs can differentiate into various cell types, including muscle and brain cell. The aim of this study is to investigate the differentiation of BMSCs through co-culture system with SCs. Pure SCs and BMSCs were cultured as control group. Expression of GFAP, P75 and NF were determined by immunocytochemical staining and reverse transcriptase polymer chain reaction(RT-PCR) was conducted to confirm mRNA expression of NF and NSE in BMSCs co-cultured with SCs. Following co-culture time with SCs, BMSCs underwent morphological changes similar to those of cultured SCs and stained positively for GFAP, P75 and NF protein. Electrophoresis analysis revealed that the levels of NF and NSE on BMSC co-cultured with SCs related with other group maintained up to 21 days. Our results showed that BMSCs able to differentiate into SC-like cells using co-culture system in vitro. These findings could be helpful for the development of the cell-based therapeutic strategies for CNS repair.
SIS/PLGA 필름에서 SIS 함량이 신경계 세포의 부착과 증식에 미치는 영향
김초민 ( Cho Min Kim ),김순희 ( Soon Hee Kim ),송이슬 ( Yi Seul Song ),정수현 ( Su Hyun Jung ),김혜린 ( Hye Lin Kim ),오재민 ( Jae Min Oh ),박종학 ( Jong Hak Park ),이동원 ( Dong Won Lee ),이종문 ( John M Rhee ),강길선 ( Gil Son K 한국조직공학·재생의학회 2009 조직공학과 재생의학 Vol.6 No.4
Porcine small intestinal submucosa(SIS) derived from the submucosal layer of porcine intestine, both generate a minimal inflammatory response following implantation and have been approved by the FDA for many types of biomedical applications. Poly(lactic-co-glycolic acid)(PLGA) is a biodegradable synthetic polymer with acceptable mechanical strength and well-controlled degradation rate. Also, it can be easily fabricated into many shapes. In this study, we fabricated natural/synthetic biomaterial hybrid films using 0, 10, 20, 40 and 80 wt% of SIS. Schwann cells(SCs) and olfactory ensheathing cells(OECs) were seeded on SIS/PLGA film and confirmed the effects of adhesion and proliferation on SCs and OECs according to content of SIS. We confirmed that specific 10~20 wt% SIS in SIS/PLGA films was superior to adhesion and proliferation of SCs and OECs and content of SIS such as 40 wt% and 80 wt% could not help cell growth and proliferation.