• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표회 논문집(I)
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• pp.145-150
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• 1998

This study deals with the effect on performance of epoxy resign mortar mixed special cement for surface control and maintenance of aging concrete construction. The test of main property of epoxy resign in this study are the evaluation on the adhesive strength between substrate and epoxy resign mortar under the environment of wet or concrete substrate surface. We gained the test results of good adhesive strength over 15 kgf/$\textrm{cm}^2$ under the wet and dry condition of concrete surface.

• 대한소아치과학회지
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• 제30권1호
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• pp.69-79
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• 2003

자가중합형 아크릴릭 레진에 polyp를 혼합하지 않은 대조군, 그리고 레진 분말에 대한 polyP(사슬길이 13과 18의 혼합물인 Calgon)의 무게비를 1%로 혼합한 polyP 1%군, 2% 혼합한 polyP 2%군 및 3% 혼합한 polyP 3%군으로 분류하여 경화시킨 후, 경화된 각각의 레진과 실험균주 S. mutans GS5, S. sobrinus 6715, S. gordonii G9B및 Challis, 그리고 P. gingivalis 2561과 Candida albicans ATCC90027을 대상으로 레진표면에 대한 미생물들의 부착의 정도, 성장 억제효과 및 접촉각의 변화를 관찰하여 그 결과로 미루어 아크릴릭 레진에 포함된 polyP는 구강 미생물에 대해 직접적으로 강한 항균 효과를 나타내지는 않는 것으로 판단되나 미생물의 부착 특히 우식원인균인 mutans streptococci의 부착을 방해하는 것으로 가늠되며, 이는 polyP의 첨가에 의한 아크릴릭 레진 표면에서 일어난 소수성의 변화가 일부 관여하는 것으로 여겨진다. PolyP가 혼합된 아크릴릭 레진의 장착은 일반적인 아크릴릭 레진으로 제작된 가철성 장치를 장착한 후 나타날 수 있는 우식 이환의 가능성을 감소시킬 수 있는 임상적 적용 가능성을 제시하였다고 여겨진다.

• Journal of Korean Dental Science
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• 제8권2호
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• pp.82-88
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• 2015

Purpose: To evaluate the effect of light-curing on the immediate and delayed micro-shear bond strength (${\mu}SBS$) between yttria-tetragonal zirconia polycrystal (Y-TZP) ceramics and RelyX Ultimate when using Single Bond Universal (SBU). Materials and Methods: Y-TZP ceramic specimens were ground with #600-grit SiC paper. SBU was applied and RelyX Ultimate was mixed and placed on the Y-TZP surface. The specimens were divided into three groups depending on whether light curing was done after adhesive (SBU) and resin cement application: uncured after adhesive and uncured after resin cement application (UU); uncured after adhesive, but light cured after resin cement (UC); and light cured after adhesive and light cured resin cement (CC). The three groups were further divided depending on the timing of ${\mu}SBS$ testing: immediate at 24 hours (UUI, UCI, CCI) and delayed at 4 weeks (UUD, UCD, CCD). ${\mu}SBS$ was statistically analyzed using one-way ANOVA and Student-Newman-Keuls multiple comparison test (P<0.05). The surface of the fractured Y-TZP specimens was analyzed under a scanning electron microscope (SEM). Result: At 24 hours, ${\mu}SBS$ of UUI group ($8.60{\pm}2.06MPa$) was significantly lower than UCI group ($25.71{\pm}4.48MPa$) and CCI group ($29.54{\pm}3.62MPa$) (P<0.05). There was not any significant difference between UCI and CCI group (P>0.05). At 4 weeks, ${\mu}SBS$ of UUD group ($24.43{\pm}2.88MPa$) had significantly increased over time compared to UUI group (P<0.05). The SEM results showed mixed failure in UCI and CCI group, while UUI group showed adhesive failure. Conclusion: Light-curing of universal adhesive before or after application of RelyX Ultimate resin cement significantly improved the immediate ${\mu}SBS$ of resin cement to air-abrasion treated Y-TZP surface. After 4 weeks, the delayed ${\mu}SBS$ of the non-light curing group significantly improved to the level of light-cured groups.

• 공업화학
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• 제27권6호
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• pp.633-638
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• 2016

본 연구에서는 상용화된 양이온교환수지, 음이온교환수지, 혼합이온교환수지 각각 3종을 이용하여 Cs과 I 등의 방사성이온을 포함하고 있는 오염수 중 방사성 이온을 분리하는 연구를 하였다. 실험은 상온에서 회분식으로 진행하였으며, 이온교환수지의 양을 달리하여 각각의 이온교환수지에 대한 Cs와 I의 제염성능을 비교하였다. 이온크로마토그라피 기기로 농도분석을 한 결과, D사의 이온교환수지의 대체적으로 이온교환능력이 높은 결과 값을 가졌으며, 공통적으로 이온교환수지의 양이 적을 때, 이온교환수지 질량 대비 제염성능이 높은 것을 알 수 있었다. D사의 양이온교환수지의 질량이 적을 때, Cs 이온에 대한 이온교환용량은 0.199 meq/g, 음이온교환수지의 I 이온에 대한 이온교환용량은 0.344 meq/g의 결과 값을 확인할 수 있었으며, 혼합이온수지를 사용했을 때에는 I 이온에 대한 이온교환용량이 0.33 meq/g으로, D사의 이온교환수지가 다른 이온교환수지에 비해 특히 I에 대한 이온교환능력이 높은 것을 알 수 있었다.

• Journal of the Korean Wood Science and Technology
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• 제34권4호
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• pp.31-36
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• 2006

본 연구는 UF resin의 접착성능을 개선하여 그 사용처의 확대하기 위하여 각 F/U 몰비별로 제조된 UF resin에 접착성능이 우수한 지방산-글리세롤-pMDI 당량비 1:1:4인 비교적 저가의 isocyanate prepolymer접착제를 선정하여 UF resin의 수지고형분 기준으로 0 wt%(대조구), 2 wt%, 5 wt%, 10 wt%, 25 wt%, 50 wt%로 첨가 혼합하여 접착 성능을 조사하였다. 그 결과, 상태 접착력(Type 2)은 F/U 몰비 1.4에서 가장 우수한 접착력을 준내수 접착력(Type 1.5)은 FGMDI첨가량이 25% 이상에서 KS 합판 접착성 기준인 $7.5kgf/cm^2$를 모두 상회하는 $11kgf/cm^2$ 이상을 나타내었다. 상태접착력대비 준내수 접착력의 평균 감소율은 F/U 몰비가 높아질수록, 지방산-글리세롤-pMDI접착제의 첨가량이 많아질수록 그 감소의 폭이 둔화되었다.

• 대한소아치과학회지
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• 제25권4호
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• pp.797-810
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• 1998

The purpose of this study was to develop a new way of delivery system of chlorhexidine using self-curing acrylic resin. Different preparations of chlorhexidine, such as chlorhexidine varnish($Chlorzoin^{(R)}$) and chlorhexidine diacetate crystalline, were mixed into self-curing acrylic resin with different methods. Every resin plate was made and was immersed in 100ml of distilled water individually, and kept in an incubator at $37^{\circ}C$. Solution(0.8ml) was collected from the each container at every 24 hours, and the amount of released chlorhexidine in the solution was measured in an ultraviolet spectrophotometer at 255nm. Flexural strength of all of the resin plates in the Experiment 2-A and 2-B were measured using Instron at the end of the experimental periods. The results were as follows: 1. It was found that chlorhexidine was released from the experimental groups in the Experiment 1, 2-A, and 2-B. And the release of chlorhexidine from all of the experimental groups showed a pattern of sustained-release preparation. 2. It seemed likely that a condition of "dryness" reduced a release of chlorhexidine from the chlorhexidine varnish. 3. It may be stated that a method of "chlorhexidine diacetate mix" with the polymer be more efficient than a method of "Chlorzoin mix" with the monomer. 4. Although it was evident that a flexural strength of the acrylic resin plates be reduced by a mix of either Chlorzoin or chlorhexidine diacetate crystalline, it seemed likely that the resin plates except Group 4 and 5 in the Experiment 2-B may be usable in the clinical situation.

• 공업화학
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• 제8권3호
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• pp.510-516
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• 1997

Cetyl alcohol과 polyoxyethylene(20) sorbitan monooleate를 혼합한 유화제와 양친매성 resin을 용매에 용해시킨 분산상에 분산매인 물을 첨가하여 O/W 에멀젼을 제조하여 HLB(Hydrophilic Lipophilic Balance) 값과 온도변화에 따른 상변화를 관찰하였다. 양친매성 resin을 함유한 에멀젼은 이를 함유하지 않는 에멀젼보다 온도변화에 따른 상안정성이 좋다는 것을 알 수 있었다. 또한 양친매성 resin이 에멀젼 안정성에 미치는 영향을 파악하기 위해 양친매성 resin에 함유되어 있는 작용기중 하나의 작용기를 갖는 resin을 model compound로 하여 HLB값과 온도변화에 따른 에멀전 상거동을 관찰한 결과, Poly(acrylic acid)

• Elastomers and Composites
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• 제29권3호
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• pp.226-233
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• 1994

The properties of the mixed prepolymer-urethane in the range of 10-40 phr were observed. LBR and LCR have same functional group but different in structure of molecular. The viscosity of mixture depending on content of rubber, adhesive strength, thermal property and compatibility with a diluted solvent are as follows: 1. The viscosity of the mixture was influenced by solubility of the diluent for urethane resin and liquid rubber. 2. Adhesive strength showed the highest value at 30phr rubber, decreased gradually at above 30phr rubber. And LBR revealed better physical property than that of LCR. 3. The most effective factors affecting adhesive strength are molecular structure of rubber, the type of solvent, and volatility. 4. Urethane resin containing LBR showed better compatibility for solvent and faster drying velocity. 5. LBR showed more favorable compatibility and dispersion state than those of LCR by analyzing the results of SEM.

• 대한치과기공학회지
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• 제28권1호
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• pp.43-52
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• 2006

Three t-amines, 4-(dimethylamino)benzoic acid (ABA), 4-(dimethylamino)benzaldehyde (MBA), 4-(dimethylamino)benzophenone (MBP), were investigated as new visible light photoinitiators for a dental resin composite of UDMA in order to improve photopolymerization effect. Three t-amines mixed with three photosensiizers, CQ, PD and DA, respectively. And the photopolymerization effect of photoinitiators were compared with that of 4-(dimethylamino)ethyl methacrylate (AEM), the most widely used photoinitiator. The photopolymerization efficiency of UDMA containing the photoinitiator increased with irradiation time. The increase was in the order: MBP

• 유변학
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• 제10권2호
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• pp.57-64
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• 1998

A pultrusion resin impregnation (PRI) die, which has been developed recently in our laboratory, was used to pre-pare various composite system. The continuous fiber reinforced composites of glass fiber/polypropylene(GFPP) and glass fiber/polyamide 6 (GFPA) were first manufactured by means of the PRI die and then cut into chopped pellets of predet-ermined length. These pellets and either virgin or modified thermoplastic resin were melt-mixed by a twin screw extruder to prepare GF/PA/PP and GF/PA/PPMA system. The mechanical properties of these blends were investigated and discussed in terms of their morphological observations. These preliminary results revealed that this new impregnation die could be suc-cessfully applied to produce prepregs suitavle for the final shaping process.