• Journal of Periodontal and Implant Science
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• v.24 no.1
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• pp.26-38
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• 1994

The purpose of this study was to evaluate the effects of citric acid and fibrin on the regeneration of periodontal tissues using 4 normal canines of five dogs. Mucoperiosteal flap was raised and experimental defects were made at the buccal root surfaces about $4{\times}6mm$ in length. The denuded root surfaces were covered using coronally repositioning technique after root planing alone at left lower canine, root planing plus fibrin at rigth lower canine, root planing plus citric acid at left upper canine or root planning plus citric acid and fibrin at right upper canine. All of the specimens were tangentially cut(about $3-5{\mu}m$)and available for histologic analysis 1, 3, 7, 14 and 21 days after operations. The results were as follows : At one' day after operations, the amounts of fibrin were similarly higher in the group I, II and III than control group and at 3 days after operations, the apical migrations of the long junctional epithelium were prominent in the control group and group I. At 7 days after operations, the fibrin meshworks of each group were partly changed to the collagen fibers and characteristics of the fibers were almost collagenous rather than fibrinous at 14 days after operations and at 21 days after operations, the orientation of collagen fibers were partly normal in group II and group III, but not in control group and group I. Root resorptions were visible in group II and group III at 14 days after operations and more significant in group II than group III at 21 days.

• Journal of the Korea Concrete Institute
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• v.13 no.4
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• pp.346-353
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• 2001

This research investigates the mixture proportioning of waste newsprint paper fiber for thin-cement product. Waste newsprint paper fibers obtained through shredded mechanically by a dry process. Waste newsprint paper fiber reinforced cement composites was manufacted by slurry-dewatering method. The waste newsprint paper fiber reinforcement conditions (fiber mass fraction, level of substitution of virgin fibers, level of fiber beating) and processing variables (pressed, unpressed) are optimized through experimental studies and statistical analyses based on factorial design of experiments and analyses of variance. The optimized recycled waste newsprint paper fiber reinforced cement composites were technically evaluated. The results are shown to possess acceptable properties and strong potentials of the recycling of waste newsprint paper of the reinforcement of thin-cement products.

• Journal of the Korea Concrete Institute
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• v.19 no.3
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• pp.333-339
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• 2007

The purpose of this study was to enhance bond performance between recycled PET (polyethylene telephthalat) fiber and cement composites through hydrophilic treatment using maleic anhydride grafted polypropylene(mPP). The mPP with various concentration of 0%, 5%, 10%, 15% and 20% to determine effect on bond behavior of recycled PET fiber were applied as experimental variables. Dog bone shaped specimens according to JCI SF-8 was applied to evaluate the bond strength and pullout energy. The results showed increased bond strength and pullout energy as concentration of mPP. Concentration of 15% mPP showed the most effective results while 20% showed reduced performance results. Because 15% mPP ensures perfect coating while 20% makes thick coating area that resulted in crack propagation and consequent separation of PET fiber and coated area during pullout load occurred. Enhancement mechanism of bond performance of recycled PET fiber and cement composites with each concentration of mPP could be conformed through investigation of microstructure of fiber surface.

• Science of Emotion and Sensibility
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• v.26 no.1
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• pp.79-86
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• 2023

This study aims to create a highly conductive E-textile made by recycling PET with a Dip-coating process. PET fiber with hydrophobic properties is characterized by the difficulty in imparting great conductivity when both Virgin and Recycled are made of electronic fibers through a Dip-coating process. To advance the effectiveness of the Dip-coating process, a sample made of recycled PET was surface modified for 50 w 5 minutes and 10 minutes employing a Covance-2mprfq model from FEMTO SCIENCE. After that, the sample was immersed in an SWCNT dispersion (.1 wt%, Carbon Co., Ltd.) for 5 minutes, and then dip coating was conducted to allow the solution to permeate well into the sample through a padder (DAELIM lab). After the procedure was completed, the resistance measurement was measured with a multimeter at both ends and then accurately remeasured with a wider electrode. As a result of this contemplation, it was affirmed that great conductivity might be given through an impregnation process through the plasma surface modification. When the surface modification was performed for 10 minutes, the resistance was reduced by up to 2.880 times. Dependent on the results of this research, E-fibers employed in the smart wearable sector can also be made of recycled materials, improving smart wearable products that can save oil resources and reduce carbon emissions.

• Journal of Life Science
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• v.12 no.3
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• pp.306-316
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• 2002

The ultrastructural change of sciatic nerve and immunohistochemical changes of NGF, PCNA were studied at the transplanted segment of intravascular cultured neural stem cell in the rat sciatic nerve by 5 months after the sciatic nerve transection. The transplanted intravascular neural stem cells were differentiated into Schwann reals at the 20th day and these cells began to regenerate by the proliferation and hypertrophy. There were many remyelinating Schwann cells in the transplanted nerve in term of stimulation. According to NGF finding, we suggest preexisting Schwann cells may induce the differentiation of neural stem cells into regenerating Schwann cells. Electron microscopic changes were the remyelinating appearance, the increase of intraaxonal microtubules and enlarged mitochondria and contacting tell processes each other.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.187-187
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• 2010

최근 해상풍력 블레이드가 대형화됨에 따라 보다 가볍고 강한 재료가 요구되고 있다. 현재 주로 사용되고 있는 복합재는 발사우드나 PVC 폼 등을 코어소재로 하고, 유리섬유나 탄소섬유 등을 보강섬유로 사용하고 있다. 본 연구에서는 현재 사용되고 있는 복합재에 대한 특성을 알아보고, 최근 흡음, 충격 및 열에 강한 발포 알루미늄을 이용한 복합재를 해상풍력 블레이드 제조에 적용하여, 구조 강도 실험을 실시함으로써 기존 복합재와 구조 강도 및 비용 등을 비교 검토하여 우수한 복합재를 제시하고자 한다. 이를 위해 대형구조물인 블레이드를 제작하기 위해 적절한 크기의 발포 알루미늄을 상호 접합하기 위한 방법을 연구하고자 하며, 목포대학교에서 보유중인 만능재료시험기(100 Ton)를 활용하여 인장, 압축, 굽힘 실험을 실시하고, 스킨재 변화, 코어재의 밀도와 두께 변화를 고려하여 다양한 복합재의 강도를 비교하고자 한다. 또한, 기존에 사용되고 있는 복합재와 발포 알루미늄을 이용한 복합재의 재료비 및 가공비를 추정하고 경제적인 복합재를 제시하고자 한다.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.159.2-159.2
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• 2011

In this study, we prepared the activated graphite nanofibers (A-GNFs) via chemical activation with KOH reagent. The effect of A-GNFs on the surface and textural properties of Ni-loaded graphite nanofibers (Ni/GNFs) was investigated by X-ray diffraction (XRD), transmission electron microscope (TEM), and Brunauer-Emmett-Teller (BET). The textural properties of samples were investigated by $N_2$/77K adsorption isotherms. The electrochemical performances were investigated by cyclic voltammetry. As a results, the electrochemical performances of Ni/GNFs were improved with usage of A-GNFs. This could be interpreted by the high specific surface area and large total pore volume of the A-GNFs.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.299-301
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• 2007

An organic-inorganic hybrid solar cell fibers with characteristics such as formability, low-cost and tailorability was developed by deposition of C60 and CuPc on fiber surface. In spite of some variation according to the temperature of ITO deposition, the maximum open circuit voltage of 0.39V was attained at $150^{\circ}C$(1000end). The resulting solar cell showed the performances Isc=0.482, Voc=0.320, FF=0.285 ${\eta}_{e}=0.044$% which are comparable to one of other types of solar cells in literature.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.323-325
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• 2007

$TiO_{2}$ electrode electrospun directly onto the substrate was developed for energy conversion device. To enhance energy conversion efficiency of dye-sensitized solar cell, electrodes should have higher surface area to absorb more dyes and higher conductivity to reduce recombination of generated electrons. $TiO_{2}$ nanofibers with higher surface areas were fabricated by annealing electrospun $TiO_{2}/PVP$ nanofibers at $500^{\circ}C$ for 3 hrs in air. it was revealed that $TiO_{2}$ nanofiber electrodes is hybrid with MWNT showed higher conductivity than $TiO_{2}$ semiconductor electrode possibly due to band gap change.

• Proceedings of the Korean Fiber Society Conference
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• 1998.04a
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• pp.315-319
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• 1998

셀룰로오스 용매계는 크게 직접용매계와 간접용매계로 나뉠 수 있으며, 잘 알려진 "비스코스 레이온(viscose rayon)"공정은 공정 중간단계에 이황화탄소(CS$_2$)를 사용하여 셀룰로오스 크산테이트 유도체를 만들고 이를 다시 수산화나트륨에 용해시키는 간접용매계에 속한다. 수산화나트륨 수용액에 용해된 비스코스 용액은 응고 욕내에서 황산과 반응하여 셀룰로오스로 재생이 되는데 비스코스 용액의 재생과정에서 발생하는 이황화탄소는 그 자체가 독성이 심한 가연성 액체일 뿐만 아니라 부반응을 통하여 삼황화소다(sodium trithiocarbonate) 및 황화수소(H$_2$S)를 발생한다.(중략)