• 대한건축학회논문집:구조계
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• 제35권6호
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• pp.121-128
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• 2019

There is a big move to build zero-energy buildings in the form of passive houses that reduce energy waste worldwide. Korea has set a goal of reducing its greenhouse gas emissions by 37% by 2030 through the activation of green buildings, such as strengthening the energy levels of new buildings and improving the energy efficiency of existing buildings. The use of insulation with high insulation performance is one of the key technologies to realize this, and vacuum insulation is the next generation insulation that blocks the energy flow of the building. In this study, we measured the bonding structure of dry and wet processing glass fiber core materials and compared the insulation performance of vacuum insulation panel. In addition, the insulation performance of vacuum insulation panel was measured according to the thickness of the laminated core. It can be confirmed that the lamination structure of the core and the lamination thickness are important factors for the heat insulating performance of the vacuum insulating panel.

• Restorative Dentistry and Endodontics
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• 제27권2호
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• pp.150-157
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• 2002

One of the latest concepts in bonding are "total etch", in which both enamel and dentin are etched with an acid to remove the smear layers, and "wet dentin" in which the dentin is not dry but left moist before application of the bonding primer Ideally the application of a bonding agent to tooth structure should be insensitive to minor contamination from oral fluids. Clinically, contaminations such as saliva, gingival fluid, blood and handpiece lubricant are often encountered by dentists during cavity preparation. The aim of this study was to evaluate the effect of contamination by hemostatic agents on shear bond strength of compomer restorations. One hundred and ten extracted human maxillary and mandibular molar teeth were collected. The teeth were removed soft tissue remnant and debris and stored in physiologic solution until they were used. Small flat area on dentin of the buccal surface were wet ground serially with 400, 800 and 1200 abrasive papers on automatic polishing machine. The teeth were randomly divided into 11 groups. Each group was conditioned as follows : Group 1: Dentin surface was not etched and not contaminated by hemostatic agents. Group 2: Dentin surface was not etched but was contaminated by Astringedent$^{\circledR}$(Ultradent product Inc., Utah, U.S.A.) Group 3: Dentin surface was not etched but was contaminated by Bosmin$^{\circledR}$(Jeil Pharm, Korea.). Group 4: Dentin surface was not etched but was contaminated by Epri-dent$^{\circledR}$(Epr Industries, NJ, U.S.A.). Group 5: Dentin surface was etched and not contaminated by hemostatic agents. Group 6: Dentin sorface was etched and contaminated by Astringedent$^{\circledR}$. Group 7 : Dentin surface was etched and contaminated by Bosmin$^{\circledR}$. Group 8: Dentin surface was etched and contaminated by Epri-dent$^{\circledR}$. Group 9: Dentin surface was contaminated by Astringedent$^{\circledR}$. The contaminated surface was rinsed by water and dried by compressed air. Group 10: Dentin surface was contaminated by Bosmin$^{\circledR}$. The contaminated surface was rinsed by water and dried by compressed air. Group 11 : Dentin surface was contaminated by Epri-dent$^{\circledR}$. The contaminated surface was rinsed by water and dried by compressed air. After surface conditioning, F2000$^{\circledR}$ was applicated on the conditoned dentin surface The teeth were thermocycled in distilled water at 5$^{\circ}C$ and 55$^{\circ}C$ for 1,000 cycles. The samples were placed on the binder with the bonded compomer-dentin interface parallel to the knife-edge shearing rod of the Universal Testing Machine(Zwick Z020, Zwick Co., Germany) running at a cross head speed or 1.0 mm/min. Group 2 showed significant decrease in shear bond strength compared with group 1 and group 6 showed significant decrease in shear bond strength compared with group 5. There were no significant differences in shear bond strength between group 5 and group 9, 10 and 11.

• Journal of the Korean Wood Science and Technology
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• 제12권1호
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• pp.3-10
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• 1984

본(本) 연구(硏究)는 토란분말(土卵粉末) 및 밀가루 분말(粉末)을 알카리와 반응(反應)시켜 제조(製造)한 접착제(接着劑)를 합판용(合板用)으로 개발(開發)코저 실시(實施)하였다. 토란(土卵) 및 밀가루 접착제(接着劑) 대(對) 요소수지(尿素樹脂)의 비(比)를 각각(各各) 0:100, 10:90, 20:80, 30:70, 40:60, 50:50, 60:40, 80:20, 100:0으로 혼합(混合)하여 합판접착(合板接着)에 적용(適用)하였으며 또한 비교실험(比較實驗)을 위하여 요소수지(尿素樹脂)에 대한 통상적(通常的)인 증량방법(增量方法)인 밀가루 분말(粉末) 대(對) 요소수지(尿素樹脂)와의 증량비(增量比)를 10:90, 20:80, 30:70, 40:60, 50:50으로 혼합(混合)한 접착제(接着劑)로 합판(合板)을 제조(製造)하여 그 접착력(接着力)을 비교(比較) 분석(分析)하였다. 토란접착제(土卵接着劑)에 요소수지(尿素樹脂)를 30:70의 비(比)로 혼합(混合)한 것이 상태(常態) 및 내수접착력(耐水接着力)에서 가장 우수한 토란접착제(土卵接着劑)에 요소수지(尿素樹脂)를 혼합(混合)하여 제조(製造)한 합판(合板)의 상태접착력(常態接着力)은 혼합비(混合比) 60:40 까지는 같은 혼합비(混合比)의 밀가루 접착제(接着劑)를 혼합(混合)한 것과 밀가루 분말(粉末)을 증량(增量)한 것보다 높은 값을 나타냈다. 밀가루 접착제(接着劑)에 요소수지(尿素樹脂)에 혼합(混合)한 합판(合板)의 상태접착력(常態接着力)은 밀가루 분말(粉末)을 증량(增量)한 것과 비교(比較)하여 혼합비(混合比) 20:80(밀가루 접착제(接着劑) : 요소수지)까지는 비슷한 값을 보이다가 혼합비(混合比) 30:70에서부터는 높은 값을 나타내고 있다. 토란접착제(土卵接着劑) 및 밀가루 접착제(接着劑)를 요소수지(尿素樹脂)에 혼합(混合)한 합판(合板)의 내수접착력(耐水接着力)은 혼합비(混合比) 40:60(토란(土卵) 및 밀가루 접착제(接着劑) : 요소수지(尿素樹脂)) 까지는 밀가루 분말(粉末)을 증량(增量)한 것보다 훨씬 높은 값을 나타내었다. 토란접착제(土卵接着劑)를 혼합(混合)한 것은 밀가루 접착제(接着劑)를 혼합(混合)한 것과 비교(比較)하여 전혼합비(全混合比)에서 높은 내수접착력(耐水接着力)을 보였다. 밀가루 분말(粉末)을 직접(直接) 증량제(增量劑)로 가용(使用)한 것보다 알카리와 반응(反應)시켜 만든 토란접착제(土卵接着劑) 및 밀가루 접착제(接着劑)를 혼합(混合)한 것이 상태(常態) 및 내수접착력(耐水接着力)을 상당(相當)히 증진(增進)시킬 수 있었는데 이것은 제조(製造)된 접착제(接着劑) 자체(自體)가 접착성(接着性)을 갖기 때문에 나타난 결과(結果)로 생각된다.

• 한국도로학회논문집
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• 제13권3호
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• pp.75-82
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• 2011

도로표지용 도료의 품질기준은 KS M 6080의 품질기준을 만족하는 제품들의 경우에도 시공 후 일정기간이 경과한 후에는 도료 자체의 부착력 문제로 교통량 증가에 따른 자동차 차륜에 의한 도료 자체의 마모 손실에 의하여 재귀반사 기능을 부여하는 유리알의 마모 및 탈리로 시인성이 급격히 저하되고 있다. 이에 따른 야간 교통 사고율 증가와 동시에 추가 교통 안전을 위한 부가 보완시공으로 안전시설 제비용이 직접비용으로 유발되고 있으며, 직접비용보다 추가공사로 인한 교통체증으로 사회간접 비용이 증가되고 있다. 특히, 차선의 품질 규격이 KS M 6080 제품에 만족한다 하더라도 빗물의 수막(水膜)에 의한 유리알의 굴절율 차로 재귀반사기능을 하는 차선 도료용 유리알의 기능을 발휘하지 못하여 운전자의 시인성은 열악함을 알 수 있다. 따라서, 국외에서 많이 사용되고 있는 마모성이 우수한 수용성 차선도료, 고성능 융착식 도료, 상온경화형 도료를 도입하여 성능을 비교 검토하였다. 본 연구에서는 차선재료의 내구성 향상을 위해 EN 1436규격에 의한 내마모성 시험을 수용성, 융착식, 상온경화형 도료에 실시하여, 재귀반사도 성능이 우수한 차선재료의 적용 가능성을 확인하였다.

• Restorative Dentistry and Endodontics
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• 제13권2호
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• pp.323-334
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• 1988

The purpose of this study was to observe the effect of dentin surface conditioners on the dentin surfaces. Freshly extracted human molars were used in this study. They were stored at $4^{\circ}C$ saline solution before experiment. The crown portions of the teeth were cut in various directions by means of wet diamond point to expose dentin which include transverse, vertical oblique, horizontal and oblique cut to the long axis (Fig. 1). Each tooth was then mounted with self curing acrylic resin in brass ring to expose the flattened dentin surfaces. Final finish was accomplished by grinding the dentin specimens with wet No. 180 and No. 600 grit silicon carbide abrasive paper until a 6.0mm in diameter on a dentin surface was exposed without pulp exposure. The specimens were divided into 9 groups according to the modes of dentin treatment procedure. The following surface treatments were applied on these preparation surfaces; Group 1: unetched (control group) after finish with No. 600 silicon carbide abrasive paper. Group 2: etched with 30% phosphoric acid for 60s Group 3: etched with 10-3 solution for 60s Group 4: Cleaned with 5% NaOCl for 30s Group 5: applied Dentin Adhesit Group 6: cleaned with 5% NaOCl followed by applying the Dentin Adhesit$^{(R)}$ Group 7: applied Photo Bond on the unetched dentin followed by applying the Photo Clearfil Bright Group 8: Etched with 30% phosphoric acid followed by applying Photo Bond and Photo Clearfil Bright Group 9: etched with 10-3 solution followed by applying Photo Bond and Photo Clearfil Bright All the specimens were stored in $37^{\circ}C$ under 50% relative humidity for 24 hours before observations. The specimens in 7, 8, and 9 group, omitting the group 1 to 6, were demineralized in 10% HCl for 10s in order to observe the resin tags. All the specimens in each group were then dried at room temperature. The dried specimens were ion coated with Eiko ion coater (Eiko-engineering Co.), and observed in Hitachi S-430 Scanning electron microscope (Hitachi, Co. Tokyo) at 15KV. The following results were obtained as follows; 1. The smear layers were still remained in group 1,2,4,5, and 6. 2. There is no effect of 5% NaOCl and 30% phosphoric acid on the changes of dentin morphology 3. The dentin treated with 10-3 solution, indicating the tubules opened when the smear layer and the dental plug dissolved. 4. In case of applying the bonding agents the resin tag was not formed at the deep area of dentinal tubules, but in case of applying the Dentin Adhesit$^{(R)}$ that was not.

• Restorative Dentistry and Endodontics
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• 제34권2호
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• pp.113-119
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• 2009

본 연구의 목적은 다른 표면 젖음성을 갖는 상아질에 대한 수종의 자가접착레진시멘트의 인장접착강도를 비교하고자 하는 것이다. 이번 실험을 위해 Rely-X Unicem (3M, ESPE, St. Paul, MN, USA), Embrace Wetbond (Pulpdent, Oakland, MA, USA), Maxcem (Kerr, Orange, CA, USA) 3 종의 자기접착레진시멘트를 사용하였다. 발거한 상, 하악 대구치 60개를 미세절단기 (Acutom P-50, Struers, Copenhagen, Benmark)를 이용해 한 치아에서 $2mm{\times}2mm{\times}7mm$의 치아 시편 두개씩 얻었다. 상아질 표면을 건조 그룹은 10초간 강한 공기로 건조시켰고, 습윤 그룹은 과잉의 수분을 2 초간 거즈로 압박해 제거하였다. 상아질 표면의 젖음성을 달리한 시편에 자가접착레진시멘트를 접착한 후 상온의 상대습도 100% 상태에서 24시간 보관했고, 만능시험기 (EZ Test, Shimadzu corporation, Kyoto, Japan)를 이용해 인장접착강도를 측정했고, 분리된 접착면의 파절양상을 근관 치료용 현미경 (OPMI pro, Carl Zeiss, Oberkochen, Germany)을 이용해 20 배의 배율로 관찰하였다. $SPSS^{TM}$ Ver 10.0 (SPSS Inc., Chicago, IL, USA)을 사용하여 동일한 자가접착레진시멘트에서 상아질 젖음성에 따른 인장접착강도를 T-test로 비교하였으며, 각 자가접착레진시멘트간의 인장접착강도를 One way ANOVA test로 비교 분석하고 95% 유의수준에서 Scheffe's test로 사후검정 하였다. 실험 결과 자가접착레진시멘트의 인장접착강도는 상아질 젖음성에 영향을 받지 않았으며, 상아질 표면 젖음성과 상관없이 Maxcem의 인장접착강도가 Unicem과 Embrace의 인장접착강도보다 유의성 있는 낮은 값을 나타내었다. 또한 모든 시편의 분리된 접착면은 접착실패 양상을 나타내었다. 이상의 실험 결과로 볼 때 자가접착레진시멘트는 상아질 표면 젖음성에 상관없이 사용할 수 있을 것이라고 생각된다.

• Journal of the Korean Wood Science and Technology
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• 제35권3호
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• pp.36-44
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• 2007

본 연구의 목적은 천연자원이며 저렴한 콩기름의 이용을 위하여 기존 에폭시수지와 에폭시 콩기름(Epoxidized soybean oil: ESBO)을 혼용한 접착제의 물성과 반응성, 경화거동 및 열안정성을 구명하는 것이다. 이에 epoxy/ESBO의 혼합비율을 달리하여 접착력, 필름의 내수성, 열적성질, 반응성 및 포름알데히드와 TVOC 방산량에 대해 시험해 보았다. Epoxy resin/ESBO의 각 혼합비율에 대한 상태접착력 시험을 실시한 결과 혼합비율 9 : 1일 때 가장 우수한 접착력을 보였으며 혼합비율 2 : 8일 경우 가장 낮은 값을 보여 2 : 8과 1 : 9를 두 경우를 제외한 9가지 경우 모두 KS 합판 접착성(비내수) 규격인 $7.0kgf/cm^2$를 모두 상회하고 있었고, 준내수접착력을 실시한 결과 혼합비율이 9 : 1일 때 가장 우수하게 나타났으며 5 : 5일 때 가장 낮은 강도를 보였다. 혼합된 접착제의 내수성을 재검토하기 위해 필름을 제조하고 가열하여 필름의 상태와 두께 및 신장률을 조사한 결과 수분흡수율이나 두께 및 신장율의 변화는 없었다. Epoxy resin/ESBO의 각 혼합비율에 대한 Tg점은 $120{\sim}110^{\circ}C$ 사이에 나타났으며 가장 높은 Tg점은 혼합비율 10 : 0의 $122^{\circ}C$이며 7 : 3, 8 : 2, 9 : 1 순으로 나타났다. Epoxy resin/ESBO의 각 홉합비율에 대한 IR스펙트럼을 조사한 결과, 에폭시수지의 에폭시밴드는 모두 경화반응하나 ESBO는 완전히 경화된다고 판단하기 어렵다. Epoxy resin/ESBO의 각 혼합비율에 대한 열안정성 검토결과 ESBO 혼합 비율이 증가할수록 열안정성은 떨어지는 것을 확인할 수 있었다. 위와 같은 실험결과를 종합하여 봤을 때 epoxy resin/ESBO의 혼합접착제에서의 ESBO는 에폭시접착제의 증량제수준의 역할임을 실험을 통하여 확인할 수 있었으며, ESBO를 접착제로 활용하기 위해서는 경화반응을 유도할 수 있는 경화조건이 확립되어야 한다고 판단된다.

• 한국산림과학회지
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• 제51권1호
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• pp.41-50
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• 1981

본연구(本硏究)의 목적(目的)은 현재(現在) 증량제(增量剤)로 사용(使用)하고 있는 도인소맥분(導人小麥粉)을 국내(国內)에서 값싸게 생산(生産)할 수 있는 다른 증량제(增量剤)로 대체(代替)키 위한 가능성(可能性)을 규명하는데 있다. 증량재료(増量材料)는 옥촉서간(玉蜀黍幹), 송수피(松樹皮), 소맥(小麥), 리기다송엽(松葉), 잣나무엽(葉) 및 목분말(木粉末)을 택(択)해서 $103{\pm}2^{\circ}C$에서 24시간(時間)동안 전건(全乾)시킨 다음 60~100mesh로 분쇄(粉碎)하였다. 증량방법(増量方法)에 있어서 요소수지(尿素樹脂)는 10, 20, 30, 50%로 증량(増量)하였으며 수용성석탄산수지(水溶性石炭酸樹脂)는 5, 10, 15, 20%로 증량(増量)하였다. 본연구(本硏究)에서 얻은 결론(結論)은 다음과 같이 요약(要約)할 수 있다. 1. 요소수지(尿素樹脂)에 있어서 상태접착력(常態接着力)은 소맥분(小麥粉)이 가장 양호(良好)하였다. 2. 요소수지(尿素樹脂)에 있어서 내수접착력(耐水接着力)은 10%와 20%증량(増量)의 경우 소맥분(小麥粉)보다 목분(木粉)이 더 양호(良好)하였으나 이들 사이의 유의적(有意的)인 차이(差異)는 없었다. 3. 석탄산수지(石炭酸樹脂)의 상태접착력(常態接着力)에 있어서 5%증량((増量)의 경우 잣나무엽분(葉粉)이 가장 양호(良好)하였으나 10, 15, 20% 증량((増量)의 경우는 소맥분(小麥粉)이 가장 양호(良好)하였다. 4. 석탄산수지(石炭酸樹脂)의 내수접착력(耐水接着力)에 있어서는 소맥분(小麥粉)이 가장 양호(良好)하였다. 5. 석탄산수지(石炭酸樹脂)의 상태(常態) 및 내수접착력(耐水接着力)에 있어서 15와 20%증량((増量)의 경우 옥촉서간(玉蜀黍幹)이 소맥분(小麥粉) 다음으로 양호(良好)한 결과(結果)를 나타내었다.

• The Journal of Advanced Prosthodontics
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• 제8권3호
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• pp.224-228
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• 2016

PURPOSE. This study aimed to investigate whether dentin surface preparation with diamond rotary instruments of different grit sizes affects the shear bond strength of resin-bonded restorations. MATERIALS AND METHODS. The buccal enamel of 60 maxillary central incisors was removed with a low speed diamond saw and wet ground with silicon carbide papers. The polished surfaces of the teeth were prepared with four groups of rotary diamond burs with super-coarse (SC), coarse (C), medium (M), and fine (F) grit sizes. Following surface preparation, 60 restorations were casted with nickel-chromium alloy and bonded with Panavia cement. To assess the shear bond strength, the samples were mounted on a universal testing machine and an axial load was applied along the cement-restoration interface at the crosshead speed of 0.5 mm/min. The acquired data was analyzed with one way ANOVA and Tukey post hoc test (${\alpha}=.05$). RESULTS. The $mean{\pm}SD$ shear bond strengths (in MPa) of the study groups were $17.75{\pm}1.41$ for SC, $13.82{\pm}1.13$ for C, $10.40{\pm}1.45$ for M, and $7.13{\pm}1.18$ for F. Statistical analysis revealed the significant difference among the study groups such that the value for group SC was significantly higher than that for group F (P<.001). CONCLUSION. Dentin surface roughness created by diamond burs of different grit sizes considerably influences the shear bond strength of resin bonded restorations.

• Journal of the Korean Wood Science and Technology
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• 제17권2호
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• pp.20-25
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• 1989

This study was carried out in order to investigate the treatment effect of PEG soln which is a common dimensional stabilizer to green log. sawing panel etc, on bonding product including plywood widely-used in secondary processing unit. The 30% concentration of aqueous PEG soln. with molecular weight of 400, 1.000 and 4,000 were prepared respectively, and also dipping the veneer in the PEG soln. spreading the PEG soln. on veneer and mixing the PEG soln. in the adhesive were allowed. Then the ratio of PEG impregnation on veneer, the adhesive strength of plywood were epitomized as follows: The ratio of impregnation by PEG 4,000 at dipping condition was highest. while that by PEG 400 at same condition was lowest. However, the effect of PEG molecular weight on the ratio of impregnation at spreading condition did not occur. 2. The adhesive strength was great in the order of 4,000>400>1,000 in molecular weight of PEG at dipping and spreading conditions. In case of mixing the PEG soln. in the adhesive, the adhesive strength was great in the order of 400>1,000>4,000 in molecular weight of PEG. Throughout three treatment conditions, PEG 400 was relatively favourable with about 10kg/$cm^2$ dry strength. 3. The adhesive strength was great 10 the order of spreading >dipping >mixing condition. 4. Although adhesive strength with the 30% concentration of aqueous PEG soln. was decreased by 35% and over, compared to control (non-treatment) adhesive strength, all types of PEG treatment except mixing the PEG soln. in the adhesive exceeded the standard dry strength for common use panel. 7.5kg/$cm^2$. 5. In warm water-proof test, the adhesive strengths by all PEG treatment conditions were less than the standard wet strength, 7.5kg cot, and also delamination of glue line occured mostly in mixing in the PEG soln. in the adhesive condition.