• 패션비즈니스
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• 제13권2호
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• pp.78-86
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• 2009

When scouring and contraction finishing at $90^{\circ}C$ using Relaxer or Rotary Washer contraction and weight loss ratio in warp and weft directions were excellent. Also surface state of fabric after drying or sanding treatment was excellent without crease. Low melting polyester fabric showed a complete melting bond by heat setting(P/S) at above $160^{\circ}C$. The alkali hydrolysis reaction of polyester showed the breakpoint in the weight loss behavior test, polyester yarn showed a breakpoint ranging from 25% to 28%. This is due to the difference of the hydrolysis rate between regular polyester and soluble polyester. Initially the soluble polyester was eluted and micro-fibrillized 5 times faster than a regular polyester. At a later time, a regular polyester was reduced weight to impart a proper flexibility and drape property to the fabric. As a result of surface sanding finishing, the surface of interior fabric showed a surface state most stabilized when using Mesh No. 220 in mono 0.2d after elution finishing. When the rotation direction of sanding roller was pro-, pro-, pro-, and retro-direction, a directional effect of tuft was not shown, a writing effect as suede was exhibited and a surface state was even. Sublimation fastness was 3-4 class for polyester and 2-4 class for nylon. Light fastness 3-4 class after lapse of 100 hours and 2-4 class after lapse of 160 hours. Abrasion fastness was 3-4 class on wet and 4-5 class on dry Laundry fastness was 2-4 class. As such, the abrasion fastness is slightly reduced upon wetting and the use thereof for interior is excellent, whereas laundry fastness is slightly lowered.

• 반도체디스플레이기술학회지
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• 제15권4호
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• pp.10-15
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• 2016

In this paper, novel ball grid array (BGA) interconnection process using solderable anisotropic conductive adhesives (SACAs) with low-melting-point alloy (LMPA) fillers have been developed to enhance the processability in the conventional capillary underfill technique and to overcome the limitations in the no-flow underfill technique. To confirm the feasibility of the proposed technique, BGA interconnection test was performed using two types of SACA with different LMPA concentration (0 and 4 vol%). After the interconnection process, the interconnection characteristics such as morphology of conduction path and electrical properties of BGA assemblies were inspected and compared. The results indicated that BGA assemblies using SACA without LMPA fillers showed weak conduction path formation such as solder bump loss or short circuit formation because of the expansion of air bubbles within the interconnection area due to the relatively high reflow peak temperature. Meanwhile, assemblies using SACA with 4 vol% LMPAs showed stable metallurgical interconnection formation and electrical resistance due to the favorable selective wetting behavior of molten LMPAs for the solder bump and Cu metallization.

• Journal of the Korean Wood Science and Technology
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• 제22권4호
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• pp.13-18
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• 1994

Sapwood samples of pitch pine were treated with disodium octaborate alone by dip-diffusion, or in combination with water-repellent preservative(WRP) and methyl metacrylate(MMA). Treated samples were subjected to an accelerated leaching test for determining the improvement of leaching resistance and to soft rot and mold tests for evaluating the increase in bioefficacy, due to the addition of WRP and MMA applied as a second treatment. The addition of WRP and MMA retarded leaching of boron to some extent from treated samples and this retardation can be explained by improved water repellency of WRP and MMA treated samples. Borate /WRP and borate /MMA systems will not qualify borate treated wood for ground and fresh water contact use but may improve performance of borate treated wood in above-ground applications not subjected to continuous wetting conditions. Bioefficacy against soft rot fungi and mold fungi was improved by a second treatment with WRP. However, improvement in the performance of borate /MMA systems was not observed. Considering improvement in both resistance of leaching and bioefficacy against micro fungi by the treatment of WRP and MMA, simultaneously, the dual treatment of borate treated wood by MMA containing co-biocides might be believed as an ideal treatment system.

• 대한치과기공학회지
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• 제39권1호
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• pp.43-52
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• 2017

Purpose: Physical and chemical properties of gold is most suitable to be restored of teeth to its original state. Recently zirconia was used instead of gold because of esthetical and intimacy of human body. Because of high strength and high abrasion resistance of zirconia, all zirconia artificial tooth lead to wear the original tooth of opposite site. To preserve this original tooth, zirconia artificial tooth covered with dental ceramic glass was used. When joining the zirconia core and dental ceramic glass, difference of their thermal expansion coefficient and wetting ability is generated the residual stress at interface lead to crack. In order to solve this problem, intermediate layer what is called zir-liner was imported to decrease the residual stress and increase the bonding strength. Methods: In this study, to identify the optimum conditions for manufacturing process, various methods to rough the surface of zirconia core were adopted, and vary the thickness of interlayer, and analyzed bond strength. Results: Bond strength of sanding specimens group showed higher than that of non-sanding specimens group, and once applied intermediate layer with sanding specimens showed highest bond strength with 28 MPa. SEM photomicrographs of zirconia cores fired at $1500^{\circ}C$ showed parallel straight lines in sanding and pockmarked surface in blasting surfaces as abrasion traces. Observation of the destruction section after shear test by SEM were carried out. Liner applied non-sanding group and non-liner applied sanding group all showed interfacial crack. Sandblasting group with non-liner showed remained dental ceramic glass on the surface of zirconia. Sandblasting group with once applied liner showed partially remained liner and dental ceramic glass on the surface of zirconia. XRD analysis revealed that sandblasting group showed higher monoclinic peaks than other specimens group and this result was due to the high collision energy for stress induced phase transformation. Conclusions: A study on the improvement of bonding strength between zirconia and dental ceramic glass steadily carried out for the future to practical use.

• 한국지반환경공학회 논문집
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• 제13권4호
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• pp.45-51
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• 2012

불포화토를 대상으로 $K_0$ 압밀조건에서 삼축시험을 수행하여 전단강도를 분석하였다. 불포화 삼축압축시험에서는 대구지역에 있는 풍화토 시료를 성형하여 다양한 모관흡수력을 조절하였다. 건조 및 습윤 시 함수특성시험을 수행하여 실험치들을 van Genuchten 곡선으로 모델하였다. 함수특성곡선으로부터 모관흡수력이 유효응력에 기여하는 성분을 평가할 수 있다. 이로부터 유효응력을 산정하였으며 유효응력에 따른 전단강도를 결정하였다. 다양한 모관흡수력에 따른 전단강도는 유효응력으로 기술하였을 때, 유일한 직선으로 나타나며 포화토의 파괴포락선과 일치함을 알 수 있었다.

• Korean Chemical Engineering Research
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• 제45권4호
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• pp.356-363
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• 2007

전계발광(EL) 소자 제조용 액상 페이스트 용액의 안정성은 사용한 안정화제의 종류 및 첨가량에 크게 영향을 받았으며, 본 실험에서 사용한 안정화제 중에서 Disperbyk-180이 형광체 액상 페이스트에 대하여 넓은 첨가량 범위에서 90일 이상의 안정성을 보였다. 안정화제 Disperbyk-180을 형광체 및 유전체 페이스트 용액에 첨가하여 인쇄 실험을 수행한 결과, 층분리 현상은 일어나지 않았으며, 균일도는 기존 사용 페이스트 보다 우수한 것으로 나타났고 인쇄 시 기포 발생과 점도 변화가 매우 작았다. 특히 형광체 페이스트의 경우 균일성과 휘도가 기존의 페이스트에 비하여 상당히 향상되었으며, ITO 기판과의 접착성도 우수하였다. 안정화제 Disperbyk-180이 첨가된 페이스트를 사용하여 제조한 EL 소자는 100 V, 400 Hz에서 $57.6cd/m^2$의 휘도를 나타내었으며, 주파수 변화에 따라서 급격한 휘도 변화는 나타내지 않았다. 또한 EL 소자의 수명을 측정한 결과 반감기는 1,250시간으로 외국에서 수입되어 시판되고 있는 페이스트를 사용한 경우와 유사한 수명을 나타내었다.

• 자원리싸이클링
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• 제17권3호
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• pp.10-20
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• 2008

농업용 폐비닐의 재활용에 대한 무기충진재의 거동을 연구하기 위하여 한국환경자원공사 시화 및 정읍공장에서 세척된 PE fluff들을 각각 사용하였다. 먼저 PE 플러프에 무기충진재인 탄산칼슘과 칼펫을 배합비율별로 혼합하여 용융 압출을 통한 시험용 펠렛들을 제조한 후 프레스 몰딩을 거쳐 시료별로 시험용 시트들을 제작하였다. 이들 무기충진 복합재의 기계적 특성인 인장, 굴곡, Izod 충격시험을 실시하였고, 열적 특성인 열변형온도, vicat 연화온도, 용융흐름지수(MFI)를 시험 및 분석을 하였다. 또한 플라스틱 내부에서 무기충진재의 분산성 및 wetting정도를 확인하기 위하여 SEM을 통해 모폴로지를 조사하였다. 이들 결과로부터 물리적인 측면과 경제적인 관점에서 재생 PE와 무기충진재의 최적 배합비들을 얻었다.

• 대한기계학회논문집B
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• 제39권5호
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• pp.449-453
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• 2015

최근 표면개질을 통한 젖음성 향상을 위하여, 마이크로와 나노 구조가 계층적(hierarchical)으로 존재하는 표면에 대한 연구가 공학 및 다양한 연구 분야에서 활발하게 진행되고 있다. 계층적구조가 존재하는 표면에서 초친수성(super-hydrophillic)은 대개 물방울(water droplet)의 계면 거동에 의해 그 특성이 확인된다. 따라서, 본 연구에서는 초친수성 표면위에서의 물방울 계면 거동에 대한 실험적 연구를 수행하였다. 포토리소그래피(photo lithography)공정과 건식 식각공정을 이용하여, 정량적으로 표면을 제작하였으며, 실험 표면에서의 계면 거동은 초고속카메라로 가시화하였다. 가시화 자료를 바탕으로, 물방울 계면거동은 표면에 존재하는 마이크로 및 나노구조의 지형학적 특성에 의해 영향을 받음을 확인하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.86-86
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• 2010

Micro- and nanoscale texturing and control of surface energy have been considered for superhydrophobicity on polymer and silicon. However these surfaces have been reported to be difficult to meet the robustness and transparency requirements for further applications, from self cleaning windows to biochip technology. Here we provided a novel method to fabricate a nearly superhydrophobic soda-lime glass using two-step method. The first step involved wet etching process to fabricate micro-sale patterns on soda-lime glass. The second step involved application of $SiO_x$-incorporated DLC to generate high intrinsic contact angle on the surface using chemical vapor deposition (CVD) process. To investigate the effect of surface roughness, we used both positive and negative micro-scale patterns on soda-limeglass, which is relatively hard for surface texturing in comparison to quartz or Pyrex glasses due to the presence of impurities, but cheaper. For all samples we tested the static wetting angle and transparency before and after 100 cycles of wear test using woolen steel. The surface morphology is observed using optical and scanning electron microscope (SEM). The results shows that negative patterns had a greater wear resistance while the hydrophobicity was best achieved using positive patterns having static contact angle up to 140 deg. with about 80% transparency. The overall experiment shows that positive patterns at etching time of 1 min shows the optimum transparency and hydrophobicity. The optimization of micro-scale pattern to achieve a robust, transparent, superhydrophobic soda-lime glass will be further investigated in the future works.

• 한국건축시공학회지
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• 제19권4호
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• pp.313-322
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• 2019

본 연구는 최근 사용량이 증대하고 있는 저시멘트 배합을 대상으로 국내생산 인공경량 잔 굵은골재의 혼합비율에 따른 경량콘크리트의 물성 및 강도특성을 비교 검토한 것으로서 실험결과, 프리웨팅 시간이 24시간 증가할 경우 모르타르 플로우값이 약 3~5% 감소하는 것으로 나타났으며 경량잔골재 사용에 의해 모르타르 배합에서 약 10.4%의 기건단위질량 감소효과를 얻을 수 있는 것으로 나타났다. 또한 경량굵은골재의 혼합비율에 따른 경량콘크리트의 기건단위질량은 5~10mm 크기인 LWG10 경량굵은골재의 혼합비율이 높아질수록 선형적으로 기건단위질량이 증가하였으며 LWG10 경량굵은골재를 혼합할 경우 LWG10 혼합비율에 관계없이 재령 7일에 약 30~31MPa 수준의 유사한 압축강도를 발현하였다.