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Thermal cycling 과 시효처리가 Glass-Ionomer수복재의 인장강도에 미치는 영향
이승익,백병주,김재곤,이승영,김문현 大韓小兒齒科學會 1999 大韓小兒齒科學會誌 Vol.26 No.4
본 연구에서는 구강환경과 유사한 액상의 조건하에서의 온도변화가 광중합형 글래스아이오노머계 수복재의 인장강도에 미치는 영향을 평가하기 위해 대조군으로 2종의 재래형 glass ionomer를 선택하고 실험군으로 2종의 광중합형의 resin-modified glass ionomer와 2종의 polyacid-modified resin composite을 선택한 다음 수중에서의 thermal cycling과 시효처리를 행하였으며, 다음과 같은 결론을 얻었다. 1. 글래스아이오노머 수복재의 인장강도를 측정한 결과, polyacid-modified resin composite, resin-modified glass ionomer 그리고 재래형 glass ionomer의 순으로 나타났다. 2. 인장강도는 30일간의 시효처리로 증가되는 경향을 보였다. 3. 재래형 glass ionomer 수복재의 인장강도는 thermal cycling 처리로 증가되는 경향을 보였으며, 37℃의 증류수 중에 1시간 침적한 군과 10,000회의 thermal cycling을 비교한 결과 유의한 차이로서 강도의 증가를 나타냈다(P<0.01). 4. thermal cycling 군의 인장강도는 DR군이 45.4MPa로 최대치를, FL군이 13.4MPa로 최소치를 나타냈으며, 각 군간의 통계적 유의성을 검증한 결과 polyacid-modified resin composite의 인장강도가 나머지 군과 유의한 차이를 보였다(p<0.05). 5. 특성강도는 DR군이 48.6MPa로 가장 높은 강도치를 보였으나, Weibull 계수는 CG군이 8.9로 가장 높은 값을 보여 시험재료 중에서 가장 작은 강도의 분산을 나타냈다. This study was performed to evaluate the effect of aging and thermal cycling on the tensile strength of six commercially available glass-ionomer materials: two chemically set glass-ionomer materials(Fuji Ⅱ, fuji Ⅸ), two resin-modified glass-ionomer materials(Fuji Ⅱ LC, Vitremer), and two polyacid-modified composite resins(Compoglass, Dyract). Rectangular tension test specimens were fabricated in a teflon mold giving 5mm in gauge length and 2mm in thickness. All samples were divided into 3 groups. Group 1 was immersed in a 37℃ distilled water for 1 hour. Group 2 was immersed in a 37℃ distilled water for 30 days. Group 3 was subjected to 10,000 thermal cycles between 5℃ and 55℃, and the immersion time in each bath was 15 seconds per cycle. Tensile testing was carried out at a cross-head speed of 0.5mm/min and fracture surfaces were examined with scanning electron microscope. The results obtained were summarized as follows; 1. The polyacid-modified composite resins were stronger than the resin-modified glass-ionomer materials, which were much stronger than the conventional glass-ionomer materials. 2. Tensile strengths were slightly increased after aging treatments for 30days. 3. Tensile strengths of conventional glass ionomers were significantly increased after thermal cycling treatment(p<0.01). 4. The highest tensile strength value of 45.4MPa was observed in the Dyract group and the lowest value of 13.3MPa was observed in the Fuji Ⅱ LC group after the thermal cycling test, and the strengths of polyacid-modified composite groups were significantly higher than those of other groups. 5. The highest characteristic strength value of 48.6MPa was obtained in the Dyract group, however the highest Weibull modulus value of 8.9MPa was obtained in the Compoglass group after thermal cycling test.
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이재곤,신장규,이정희,최시영 경북대학교 센서기술연구소 1995 센서技術學術大會論文集 Vol.6 No.1
The surfaces of (100) InSb were analyzed by Auger electron spectroscopy before and after sulfur treatment. The Auger spectrums for In_(2)O_(3), Sb_(2)O_(3), and elemental Sb were detected in the native oxide of InSb surface. After the sulfur treatment by ammonium sulfide((NH_(4))_(2)S_(x)), carbon content stays almost constant, but a great deal of the surface oxygen is replaced by sulfur, probably as a surface InSb-sulfide. For the case of the surfce which was sulfur treated during 2min at 25℃, carbon, oxygen and sulfur concentrations at surface were 11%, 6%, and 34%, respectively, and the In/Sb surface ratio was 1.0.
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석회석을 이용한 칼사이트형 탄산칼슘의 제조 및 분산특성 연구
이재장,박종력,김병곤,장광택 강원대학교 부설 석재복합신소재 제품연구센터 2002 석재연 논문집 Vol.7 No.-
석회석은 국내 비금속 광물자원의 대부분을 차지하며 강원도와 충북 등의 일부지역에 편재되어 부존하고 있다. 그러나 CaO 함량이 54% 이상인 고품위 석회석은 전체 매장량의 5% 이하로 매우 빈약한 편이다. 더욱이 대분분의 생산량이 1차 산업용으로 사용되어 부가가치가 낮은 용도로 활용되고 있다. 본 연구에서는 이러한 석회석의 부가가치를 향상시키기 위하여 칼사이트형 침강성 탄산칼슘을 탄산화법을 이용하여 합성하고자 하였으며, 합성된 탄산칼슘 분체 및 현탁액의 분산안정성에 대하여 조사하였다. 분산이 양호하고 균일한 입도의 칼사이트 분체를 얻기 위해서는 CaO 농도 3%, CO_2 가스 유입량 300㎖/min, 교반속도 1,000 rpm에서 탄산화반응시 반응온도를 10~30℃로 유지하여야 함을 알 수 있었으며, 현탁액의 분산안정제로 PMAA와 PAA를 첨가제로 사용시 pH 6, 9, 12에서 0.2 wt% 첨가할 때 우수한 분산안정성을 나타내었다. A limestone reserves in korea is comparatively enough and reserved mainly in Kangwon-do and Chungchongbuk-do. However, it is known that limestone of high grade, more than 54% CaO, is about under 5% of total reserves. Besides, most of them are used for manufacture of cement as a primary material of low value. In this study, calcite type calcium carbonate powder or slurry was synthesized by carbonation process using limestone and dispersion properties of the prepared calcium carbonate suspension was investigated. In the carbonation reaction, the temperature of lime milk must be kept 10∼30℃, CaO consentration of 3%, stirring rate of 1,000 rpm and CO_2 gas flow rate 300㎖/min to manufacture stable dispersion calcite. Also, in the result of measuring the precipitation height of calcite suspension at pH 6, 9 and 12 as a function of the PMAA and PAA content, stable dispersion properties was observed at 0.2 wt% of PMAA and PAA. This may be due to the formation of the distinct adsorption layer between calcite particles by dispersant.
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법랑질과 복합레진 접착부의 피로파괴에 관한 실험적 연구
이영수,김재곤,백병주 의치학사 1994 치과임상 Vol.14 No.12
This study was to evaluate the tensile bond strength and fatigue life of composite bond to enamel surface. Three kinds of composite resin restorative materials including Prisms AP. H., Clearfil Photo-Posterior, and Z 100 were used for this study. Fatigue test was conducted under peak cyclic flexural stresses fo 5.98kg/mm' and 5.42kg/md using the electro-dynamic type fatigue testing machine. The obtained results were as follows : 1. Tensile bond strengths were 1.686 0.653kg/mm' at Z100, 1.637 0.634kg/md at Prisma AP. H, and 1.584 0.361kg/mm' at Clearfil Photo-Posterior, but didn't show a significant difference (P>0.05). 2. Average fatigue life were 470,739 388,181 cycle at Z100, 195,010 306,921 cycle at Prisma AP. H, and 33, 219 93,756 cycle at Clearfil Photo-Posteiro under constant fatigue stress of 5.98kg/mm', and Z100 was significant difference with Clearfil Photo Posteior(P<0.05). 3. Among the mode of failure for the specimens, most of failure was adhesive failure and mode of failuer for Z100 was throughly distributed, but mode of failure of Clearfil Photo-Posterior was entirely adhesive failure.
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李裕燦,高在坤 단국대학교 1995 論文集 Vol.29 No.-
The purpose of this research is to examine how driver's physical and psychological condition affects on traffic offence or accident and to find the reasons. 192 people was selected as sample by means of Intended Sampling method out of 220 traffic offenders who were participating in traffic education program after consulting with some specialist about offenders condition (health), a questionnaire composed of 40 questions was mode Then the data was analyzed by the SPSS PC program of SM-430 computer. Comprehensive examining the relationships between traffic offenders and their health, drivers who got traffic accidents and their health, and overspeeding drivers and their health deduced the following results. First, even though undesirable physical and psychological condition is a subject to high frequency of offence or accident, most of drivers used to ignore these factor. Second, driver's psychological condition affects overspeeding that lead big graffic accident. Temselves should recognize the importance of such factors but also many education institutes have to analyze the main reason. And educational programs about drivers physical and psychological condition ought to be designed in the long term view.
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