• Journal of the Korean Society of Radiology
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• v.13 no.1
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• pp.15-20
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• 2019

We developed a novel depth-of-interaction positron emission tomography (PET) detector using wavelength shifting (WLS) fibers and optimized it. The optimization module was designed by using two scintillators and three WLS fibers and attaching a sensor to the end of the WLS fiber. Optimum combinations were obtained through the light collection efficiency and the light collection ratio between sensors depending on coupling materials and reflectors of scintillators, WLS fibers and sensors. The highest light collection efficiency and the light collection ratio between sensors were obtained in the combination of the epoxy (coupling materials)-diffuse reflector (scintillators)-specular reflector (WLS fibers).

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.128-129
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• 2014

In this study, flowability of the mortar added with length change and combination of steel and inorganic fiber has been tested to evaluate the performance of fiber-reinforced mortar. The following results could be made as the conclusion. Early age flow of the mortar has been decreased when fibers added. Slump also decreased with the adding of fibers. For the air content, comparing with Plain, all the specimens with fibers showed higher air content than Plain., Addition of every kinds fibers showed the similar EIS test results.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.88-89
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• 2017

Due to the increase in the usage of explosive materials and terrorism, the interest towards the superior explosion protective HPFRCC has risen. In existing research, the optimum ratio for solving the problematic problems such as the optimum fiber incorporation rate and the self-shrinkage crack of HPFRCC had been derived. However, there had been few or even no research upon how effective HPFRCC would perform protective explosion-proof in actual explosion. Therefore, this research compared the explosion-proof performance of HPFRCC according to fiber commination and mixing ratio. As a result, the combination of steel fiber and organic fiber showed excellent flow and strength, and it also improved the explosion resistance.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.58-58
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• 2001

본 연구는 섬유소 분해효소 유전자 Cel D(Cellulase Digestion)가 도입된 형질전환 돼지 생산을 통하여 섬유소 함유 사료의 이용 효율을 증대시키고, 나아가 장기이식동물 및 고가의 의료용 단백질 생산가축을 개발하기 위한 원천기술 확보에 있다. 섬유소분해 유전자의 크로닝 및 조직 특이적 발현벡터를 개발하기 위하여, 우선 소의 위중 제4위 내의 미생물로부터 전체 유전자를 분리하였고, 이렇게 작성된 DNA library에서 섬유소분해 관련 유전자인 약 2.0 kb의 Cel D유전자를 크로닝하였으며, 췌장 특이적 발현 프로모터(rat elastase I: 약 200bp)를 크로닝한 후, 미세주입용 형질전환 재조합 벡터를 구축하기 위하여 rElastase I 프로모터 하류에 섬유소 분해 유전자(Cel D)를 연결하여 약 3.0 kb 크기의 재조합 벡터를 준비하였으며, 재조합 유전자를 1세포기 수정란 전핵내에 미세주입 하기 위해 Sal I과 BglII를 이용 유전자 단편을 만들었다. 구축된 유전자를 미세주입하기 위한 수정란을 회수하기위해 총68두의 돼지를 4-5두씩 분리사육하면서 발정동기화 및 과배란 유기를 위해 PG600, Altrenogest, FSH, hCG를 투여하였으며 hCG투여후 약54시간에 외과적 방법에 의해 총 1,359개의 수정란을 회수하였고, 이중 미세주입가능한 1세포기 수정란은 1,296개로 두당 평균 15.9개 였다. 1,296개의 1세포기 수정란 중에서 재조합 유전자(rE I-CelD)가 미세주입된 660개의 수정란을 32두의 수란돈에 외과적 방법에 의해 이식하였으며, 이식되어진 모돈 13두가 분만하여 40.6%의 임신율을 나타내었다. 이렇게 분만된 13두에서 총 65두(암:33두, 수:32두)의 자돈이 생산되었으며, 형질전환 여부를 판명하기 위해 자돈의 꼬리조직으로 부터 genomic DNA를 추출하고 PCR 검정을 실시하였다. PCR 검정 결과, 섬유소 분해 유전자가 도입된 자돈은 5두 이었으며, 그 결과를 Table에 나타내었다.(Table Omitted) Table 1 에서와 같이 섬유소 분해효소유전자가 형질전환된 자돈은 65마리 중 5마리로 7.69%의 형질전환율을 나타내었으며, 5마리의 자돈중 2두(암:1두, 수:1두)는 분만 후 즉시 폐사되었으며 2두(암:1두, 수:1두)는 86일령 그리고 14일령에 폐사하여 현재 1두(암)가 생존하여 섬유소 분해 사양 실험 중에 있다.

• Journal of the Korea Institute of Building Construction
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• v.15 no.6
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• pp.615-620
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• 2015

The high performance fiber reinforced cementitious composite (HPFRCC) controls the cracking development of the structure by inducing micro-cracking and strain hardening behavior after the initial cracking under the tensile conditions. Although, in Korea, the research about manufacturing the single-fiber reinforced cementitious composite or the mechanical properties of hardened status has been conducted, the research to apply the HPFRCC with multi-fiber is not sufficient. Hence, in this research, considering the workability and economic aspect for practical applications, the engineering properties of HPFRCC with combined long steel fiber (SL) and long organic fiber (OL) are evaluated such as workability and strength. As a result of evaluating the engineering properties of HPFRCC, the most favorable performance was obtained when the mixture contained 1.5% of combined SL and OL.

• Proceedings of the Korean Fiber Society Conference
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• 1998.04a
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• pp.346-349
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• 1998

1.0 dtex이하의 섬도를 갖는 극세사 섬유는 수분율이 높아 촉감이 부드러우며 드레이프성이 우수하고 실크같은 광택효과를 갖고 있다. 그러나 극세사는 저온에서도 염착이 일어나며 넓은 표면적으로 인하여 염착속도가 빨라 불균염이 일어나기 쉽다. 또한 섬유의 직경이 작아 표면적이 넓기 때문에, 동일한 색상을 얻기 위해서는 다른 섬유로 된 직물에 비해 과량의 염료가 필요하게 되고 이로 인하여 낮은 견뢰도를 나타내며 오염물질이 고농도인 염색폐수를 방출하게 된다.(중략)

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.3
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• pp.139-148
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• 2015

The purpose of this paper is to induce the ductile behavior of the UHPFRC member after the peak load by using the bundle of longitudinal reinforcing bar as a substitute for steel fiber. Experiments on the flexural behavior of the Ultra High Performance Concrete rectangular beam with the combination of the steel fiber and longitudinal reinforcing bar were carried out. The volume fractions of steel fiber are 0%, 0.7%, 1%, 1.5%, 2% and the reinforcement ratios of longitudinal reinforcing bar which induce the ductile behavior are 0.0036, 0.016, 0.028 and 0.036. 15 UHPC beams were made with the combination of these test factors. Not only steel fiber but also bundle of longitudinal reinforcing bar has the effect to induce ductile behavior of UHPC structural member. The combination of 0.7% volume fraction of steel fiber and 0.028 reinforcement ratio showed the most economic combination. The relationship of load-deflection, strain variation of the concrete and the crack pattern indicate the usefulness of the bundle of the longitudinal bar which has small diameter with close arrangement each other.

• Proceedings of the Korean Fiber Society Conference
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• 1998.10a
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• pp.422-425
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• 1998

섬유강화 복합재료는 고성능 섬유와 고분자 수지를 조합하여 재료의 물성 향상 및 고기능화를 목적으로 만들어지는 재료이며, 사용되는 고분자 매트릭스의 종류에 따라 열가소성 복합재료와 열경화성 복합재료로 나뉘어진다. 이 중 열경화성 복합재료에 관한 연구 및 그의 실용화는 오래 전부터 활발히 진행되어 산업재료 및 군사, 우주용 재료로 각광을 받아 왔으나 최근 지구 환경문제가 심각해지면서 사용 후 분해 및 재활용이 가능한 열가소성 복합재료에 관한 연구에 관심을 가지게 되었다. (중략)

• Radiation Oncology Journal
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• v.24 no.3
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• pp.179-184
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• 2006

[ $\underline{Purpose}$ ]: To explore the effect of recombinant human EGF on the proliferation and survival of human fibroblast cell lines following irradiation. $\underline{Materials\;and\;Methods}$: Fibroblast was originated human skin and primary cultured. The trypan blue stain assay and MTT assay were used to study the proliferative effects of EGF on human fibroblast cell lines in vitro. An incubation of fibroblasts with rhEGF for 24 hours immediately after irradiation was counted everyday. Cell cycle distributions were analyzed by FACS analysis. $\underline{Results}$: Number of fibroblast was significantly more increased rhEGF (1.0 nM, 10 nM, 100 nM, 1,000 nM) treated cell than control after 8 Gy irradiation. Most effective dose of rhEGF was at 160 nM. These survival differences were maintained at 1 week later. Proportion of S phase was significantly increased on rhEGF treated cells. $\underline{Conclusion}$: rhEGF cause increased fibroblast proliferation following irradiation. We expect that rhEGF was effective for radiation induced wound healing.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.1
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• pp.18-24
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• 2016

The purpose of this study is to induce the ductile behavior of the Ultra High Perfomance Concrete Reinforced I beam by substituting the part of steel fiber for bundle of reinforcing bars. Experiment of flexural behavior of the Ultra High Performance Concrete I shaped beam with the combination of the steel fiber and bundle of reinforcement bars was carried out. The volume fractions of steel fiber are 0%, 0.7%, 1%, 2%. The bundle of reinforcing bars and prestressing wire are used to restrain the concrete in compression zone. Length of bundle of reinforcing bar and prestressing wire is the one of test factors. The 9 Reinforced UHPC I shaped beam were made with these test factors. Not only steel fiber but also bundle of longitudinal reinforcing bar has effect to induce the ductile behavior of Reinforced UHPC I beam. The combination of 0.7% or 1.0% steel fiber and bundle of reinforcing bar showed the effective ductile behavior of I beam. The relationship of load-deflection and the crack pattern indicate the usefulness of the bundle of the longitudinal bar which has small diameter with close arrangement each other.