• 한국세라믹학회지
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• 제45권8호
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• pp.486-492
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• 2008

Reaction bonded silicon carbide(RBSC) composite for heat-exchanger was fabricated by molten Si infiltration method. The raw materials with variable particle sizes were used in this experience. The finer the particle size in sintered silicon carbide was the more increasing 3-point bending strength and fracture toughness. As the adaptable particle sizes had been occupied interstice arising from packing sample, the mechanical properties were increased. In the PCS1-1 sample, the 3-point bending strength and fracture toughness were 323MPa and $4.9\;MPa{\cdot}m^{1/2}$, respectively.

• Journal of the Korean Wood Science and Technology
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• 제33권3호통권131호
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• pp.38-44
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• 2005

소나무, 낙엽송 및 잣나무 간벌재로 톱밥보드를 만든 후 소성시 승온속도와 최고온도에서 유지시간을 달리하여 우드세라믹을 제조하고 그 물성을 조사하였다. 승온속도가 빠를수록 밀도 및 두께감소율은 감소하였고 길이감소율 및 중량 감소율은 증가하였다. 최고온도에서 유지시간이 증가할수록 길이감소율 및 두께감소율은 증가하였다. 열전도성은 승온속도 $2^{\circ}C/min$와 최고온도에서 유지시간 2시간일 때의 조건으로 제조된 우드세라믹이 가장 우수하였다.

• Korean Chemical Engineering Research
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• 제52권1호
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• pp.63-67
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• 2014

페놀-포름알데히드를 이용하여 레졸형 구형 페놀수지 입자를 합성함에 있어 반응물의 조성이 입도분포, 수율 및 밀도에 미치는 영향을 확인하였다. 분산매의 양을 감소시킴에 따라 현탁액의 점도가 증가하며 이로 인해 입도분포의 변화 및 응집 현상의 원인이 됨을 확인하였고, 안정제의 양을 증가시킴에 따라 현탁입자의 표면적을 증가시키기 위해 평균입도가 감소하는 것을 확인하였다. 적정량 이상의 경화제의 사용은 입도분포 및 수율에는 영향을 미치지 않으나 형성된 입자 내부의 격렬한 경화반응으로 인해 발생하는 물분자의 탈출이 원활하지 않게 되어 밀도가 감소하는 것을 SEM 사진을 통해 확인하였다.

• Bulletin of the Korean Chemical Society
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• 제30권8호
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• pp.1798-1804
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• 2009

In this study, we have studied on improved performance of carbon nanotubes/titanium (CNT/TiO2) structure electrode for methylene blue (MB). The composite electrodes consisting of CNTs and a titanium oxide matrix with phenol resin binder was fabricated with a mixture method. The chemical and morphological structure of CNT/Ti$O_2$ composites were characterized by means of BET surface area, X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Vis absorption technique, Raman spectroscopy and energy dispersive X-ray (EDX). The electrode showed a remarkably enhanced performance for MB oxidation under UV illumination with or without electro-chemical reaction (ECR). Such a remarkably improved performance of the CNT/Ti$O_2$ structure electrode might be due to the enhanced MB oxidation by electro- and photo-generated electrons and holes in the CNTs and Ti$O_2$ under UV illumination with or without ECR.

• 한국세라믹학회지
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• 제46권5호
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• pp.528-533
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• 2009

High purity $\beta$-SiC powders were synthesized using sol-gel processing. TEOS and phenol resin were used as the starting material for the silicon source and carbon source, respectively. The process turned out to be capable of producing high purity SiC powder purity degree with 99.98 %. However, it was difficult to control the shape and size of $\beta$-SiC powders synthesized by sol-gel process. In this study, $\beta$-SiC powder with size of $1{\sim}5$ um an 30 nm were used as the seeds for $\beta$-SiC to control the $\beta$-SiC powder morphology. It was found that $\beta$-SiC powder seeds was effective to increase the powder average size of synthesized $\beta$-SiC using sol-gel process by acting as the preferred growing sites for $\beta$-SiC.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2001년도 추계학술발표회 초록집
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• pp.3-3
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• 2001

Two companies plating baths were selected for plating on phenol and epoxy resin boards as well as on flexible p polyimide boards. After plating, deposited i&IIk&.ness al1d physical properties, as well as solder wettabilities by aging with $150^{\circ}C$ heating and 100% humidity were compared. After plating and aged with two different tin baths, deposited thickness and physical properties were not so great differences, but solder wettabilities were superior used polymer catalyst than the other. Furthermore depend upon the compactness and fineness of metallic sturctures of the base copper, the amounts of the plated copper were big differel1lces. These differences seems to be inherited from the kind and amount of additives. as well as current densities, which are influences upon structures of Copper layers. Generally the tin thickness are hetween 0.5 to $1.0\mu\textrm{m}$ and thicker the solder wettabilities are the better, and also me compact structures of deposits showed gooo soidierabiiities. In this study, with our own deveiotaedl plating equipment could get more than $0.5\mu\textrm{m}$ of till thickness and piating speed was $0.1\mu\textrm{m}$ per minutes.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2008년도 춘계학술대회
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• pp.191-197
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• 2008

In this study, as a fuel filter for automobiles, base paper which can filtrate the polluted particles must satisfy with the standards of each vehicle. and a filter of impregnation paper made that combining the base paper with the resin. Therefore, They were wanted to found out the factors that affect base paper and impregnation paper according to content of HPZ, Mulberry pulp(MP), Laub holze bleached kraft pulp(LBKP). The most important things we wanted to find out in base paper and impregnation paper test were weight, thickness, air permeability, burst and tensile strength, maximum pore size and mean pore size, stiffness. we wanted to measure a rate of change of these condition by adjusting a rate of mixing for HPZ, MP and LBKP. Moreover, It suited for an impregnation paper mixed with a rate of mulberry pulp 20%, HPZ 40% and LBKP 40%. Used resins in this study was Phenol, Acryl, PVAc. And as every resins, sample was divided into existence and nothing of embossing. as a fuel filter for automobiles, It was appeared that the suitable condition of base paper was a rate of mixing for HPZ(40%), MP(20%) and LBKP(40%).

• Journal of the Korean Wood Science and Technology
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• 제51권2호
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• pp.81-97
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• 2023

The aim of this study were to evaluate tannin resorcinol formaldehyde (TRF) for the preparation of cross-laminated timbers (CLTs) made from fast-growing tree species and to analyze the physical and mechanical properties of CLTs. TRF copolymer resin was prepared by using the bark extracts of Swietenia mahagoni (L.) Jacq. It was observed that the TRF adhesive possessed less solid content (23.59%), high viscosity (11.35 poise), and high pH values (10.0) compared to the standard phenol resorcinol formaldehyde. The TRF adhesive was applied to produce CLTs with the addition of 15% tapioca and flour as an extender. The six-layered CLTs were produced from sengon (Falcataria moluccana Miq.), jabon [Anthocephalus cadamba (Roxb) Miq.], coconut (Cocos nucifera L.), and the combination of coconut-jabon and coconut-sengon wood. The analysis of variance revealed that the layer composition of CLT significantly affected the physical and mechanical properties of the beam. While the modulus of rupture met the standard, the moisture content and modulus of elasticity values did not fulfill JAS 1152-2007. All of the CLTs produced in this study demonstrated low formaldehyde emission, ranging from 0.001 mg/L to 0.003 mg/L, thereby satisfying the JAS 1152 for structural glue laminated timber.

• Composites Research
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• 제12권3호
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• pp.84-90
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• 1999

HAC/PVA계 MDF시멘트 복합재료의 수분안정성 및 기계적 강도향상을 위하여 불용성 폴리머류(폴리우레탄, 페놀, 에폭시수지)와 탄소섬유(길이3mm)를 1-4wt% 보강하였다. 그리고 가압성형법으로 제조한 복합체의 수분침적 기간별 강도특성(수분안정성)과 계면 및 기계적 특성에 영향을 미치는 폴리머와 시멘트의 가교반응에 대하여 SEM 및 TEM 분석을 통하여 관찰하였다. HAC/PVA계 MDF 시멘트 복합체의 섬유함량에 따른 건조 굽힘강도는 섬유함량이 증가할수록 치밀화 구조가 저하되어 비례적으로 감소되었다. 또한 불용성 폴리머류를 사용한 경우에 건조 굽힘강도는 섬유함량이 증가될수록 저하되는 반면, 수분안정성은 크게 향상되었다. 에폭시 수지를 첨가한 경우에 수분안정성이 가장 우수하였으며, 섬유함량 4% 첨가의 경우에 3일 침적강도가 95%, 7일침적시 87%강도를 유지하였다. 이 점은 폴리머와 시멘트의 금속이온이 가교반응을 일으켜 섬유-메트릭스간 계면 부착강도를 크게 개선되었기 때문으로 추정된다. 반면 인장강도 특성은 모든 불용성 폴리머류 첨가 수준에서 섬유 함량이 증가할수록 비례적으로 증가되었으며, 역시 에폭시 수지 첨가의 경우에 강도특성이 가장 우수하였다. 그리고 섬유함량 4% 첨가된 경우에 있어서 인장강도는 섬유함량 0% 대비 약 30~80% 높게 나타났다.

• Journal of the Korean Wood Science and Technology
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• 제43권4호
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• pp.528-537
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• 2015

폐기물의 재활용을 도모하기 위해 음식점이나 정육점에서 폐기되는 뼈(골분)를 합판용 접착제의 충전제로서 이용 가능성을 검토하였다. 현재 업계에서 합판의 제조에 사용되고 있는 3종의 접착제(UMF, UF 및 PF수지)에 대해 3종의 골분(소골분, 돼지골분 및 조개골분)을 첨가하여 제조한 라티에타파인 합판의 접착성능을 기존의 소맥분과 비교하였다. 3수지에서 모두 소맥분을 전부 소골분, 돼지골분 및 조개골분으로 각각 대체한 합판의 접착성능은 상태나 습윤 강도 및 목파율 모두 소맥분 첨가 합판보다 낮았다. 따라서 소맥분을 전혀 첨가하지 않고 골분으로 모두 대체하는 것은 곤란하였다. 그러나, 소맥분의 절반을 소골분과 돼지골분으로 각각 대체하여 제조한 합판의 성능은 소맥분을 사용한 합판과 거의 동등하거나 오히려 우수한 내수성능을 발휘하여 소맥분과 병용해서 사용하면 충분히 이용이 가능할 것으로 생각된다. 소맥분과 병용한 경우, 3종의 골분 중에는 조개골분을 첨가하여 제조한 합판 보다는 소골분과 돼지골분을 첨가한 합판의 성능이 우수하였으며, 소골분과 돼지골분 간에는 큰 차이가 없었다.