• Restorative Dentistry and Endodontics
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• 제24권1호
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• pp.55-66
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• 1999

The purpose of this study was to evaluate the microleakage of 5 current dentin bonding systems which are composed of 2 multi-bottle systems(Scotchbond Multi-Purpose, All Bond2) and 3 one-bottle systems(Single bond, One-Step, Prime & Bond). In this in vitro study, class V cavities were prepared on buccal and lingual surfaces of sixty extracted human premolars and molars on cementum margin. The experimental teeth were randomly divided into six groups of 10 samples (20 surfaces) each, Group 1 : Scotchbond Multi-Purpose ; Group 2 : All Bond 2 ; Group 3 : Single Bond ; Group 4 : One-Step ; Group 5 : Prime & Bond ; Group 6 : no bonding agent(control). The bonding agent and composite resin were applied for each group following the manufacturer's instructions. After 500 thermocycling between $5^{\circ}C$ and $55^{\circ}C$, the 60 teeth were placed in 2% Methylene blue dye for 24 hours, then rinsed with tab water. The specimen were embedded in clear resin, then sectioned buccolingually through the center of restoration with a low speed diamond saw. The dye penetration on each of the specimen were then observed with a stereomicroscope at ${\times}20$. The results of study were statistically analyzed using the Student-Newmann-Keul's Methods and the Mann-Whitney Rank Sum Test. The resin/dentin interfaces were examined under Scanning Electron Microscopy. The results of this study were as follows. 1. None of the dentin bonding systems used in this study showed significant difference in leakage values at both the enamel and the dentin margins (P>0.05). 2. In all groups except the control, leakage value seen at the enamel margin was significantly lower than that seen at the dentin margin (P<0.05). 3. Compared to the control group, all the groups treated with dentin bonding systems showed significantly lower leakage value at both enamel and dentin margins (P<0.05). 4. In the SEM view, gaps were observed in the composite resin / dentin interface in group 6 where no dentin bonding agent was used, and in all the other groups (group 1, 2, 3, 4, 5) composite resin, hybrid layer, and dentin were seen to be closely adhering to each other where there were no leakages. Well-developed resin tags 3~100${\mu}m$ in length infiltrated dentinal tubules past the hybrid layer and a hybrid layer 1~5${\mu}m$ thick had developed between the dentinal surface and the composite resin surface.

• 대한소아치과학회지
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• 제28권4호
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• pp.566-574
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• 2001

법랑질과 상아질에 대한 접착시스템의 결합력은 타액이나 혈액에 의하여 저하될 수 있다. 제 5세대 상아질 결합제 적용시에 산부식된 치면이 타액에 오염될 경우, 보다 효율적인 치면 처리 방법을 알아보기 위해 여러 가지 치면 처리 방법과 조건을 설정한 다음 수복물의 유지력을 전단결합강도 측정으로 서로 비교 분석하고, 치아와 수복물 사이의 계면을 주사전자 현미경을 이용해 관찰하였다. 그 결과 우치상아질의 산부식후 타액오염된 경우, 물로 10초간 세척한 후 공기로 가볍게 건조하여 수복하면 전단결합강도의 감소가 일어나지 않았으나, Prime & Bond NT의 광중합후에 타액오염된 경우에는 물로 10초간 세척한 후 공기로 완전히 건조를 하여도 레진과의 결합력이 매우 약해지며 Prime & Bond NT를 재적용하더라도 전단결합강도의 상당한 감소를 보였으며, 주사전자 현미경 관찰결과 모든 군에서 유사한 혼화층과 레진태그의 형성을 보였으며 특이할만한 각 군간의 차이를 관찰할 수 없었다.

• 한국버섯학회지
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• 제2권4호
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• pp.222-224
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• 2004

병재배 느타리버섯의 품종 다양화를 위해 단핵균주교잡에 의해 육성된 소담느타리의 주요특성은 다음과 같다. 가. 소담느타리는 애느타리1호와 수한느타리1호의 단핵균주 교잡에 의해 육성 된 품종으로 균사생장 적온은 $25{\sim}30^{\circ}C$이고 버섯발생 및 생육온도는 $14{\sim}16^{\circ}C$이다. 나. 갓색은 회색이고 얕은 깔대기형이며 발이수가 많다. 다. 배양일수는 $20^{\circ}C$에서 20일, 초발이 소요일수는 3일이며 가늘고 짧은형으로 농가실증시험에서 병당 수량은 148.2g으로 높은 편이었다. 라. 균사활력이 강해 배양이 빠르므로 적기에 발이유기가 요구된다.

• 식물병연구
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• 제10권1호
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• pp.53-57
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• 2004

CGMMV는 한국에서 수박의 주요 병원균이고, 수박 생산에 심각한 영향을 미친다. 이 연구에서는 박 종자의 CGMMV를 RT-PCR을 이용하여 신속하고 민감하게 검정하는 진단방법을 개발하였다. CGMMV-W의 외피 단백질 유전자 sequence에서 제작된 CGMMV에 특이적인 primer인 Wmfl과 Wmrl은 RT-PCR에 의해 420 bp의 증폭산물을 증폭하였다. RT-PCR에 의한 진단을 위하여 바이러스 추출과정을 간소화하고 종자 추출물의 반응 억제물질을 감소시키기 위해 ethanol 침전, double filtration, PEG 침전, phenol/chloroform/isoamyl alcohol에 의한 추출법을 비교하였으며 phenol/chloroform/isoamyl alcohol에 의 한 추출법이 민감성이 강한 방법으로 선발되었다. RT-PCR을 위해 선발된 primer들과 추출법은 1,000립의 건전 종자에 1립의 이병 종자를 혼합한 수준까지 판별이 가능하였다. 신속하고 민감한 RT-PCR에 의한 본 검정방법은 높은 반응 억제물질을 함유하는 박 종자에서 CGMMV의 특이적인 진단을 위해 유용한 방법이다.

• 한국물환경학회지
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• 제25권6호
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• pp.902-909
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• 2009

With various reservoirs, dams and reduction of water velocity in downstream, rivers in Korea often have characteristics of accumulation of pollutants. Therefore, the main focus of water quality modeling in Korea needs to be shifted from DO to algae and organic matter. Moreover the structures of water quality models should be modified to have capability of simulating BOD which is a key factor of total water pollution load management in Korea as laboratory experiment BOD (Bottle $BOD_5$). In the SWAT model which is one of the widely used water quality models in Korea, the channel water quality module is using main algorithm of the QUAL2E model which has limitations in simulating algae, organic matter and Bottle BOD5 etc. To overcome this hindrance, in this study, the improved channel water quality module of the SWAT model (Q-SWAT) was proposed by linking the algorithms of the QUAL-NIER model which was developed based on the QUAL2E model to the SWAT model. The algorithms estimating the increase of internal organic matter by fractionization algal metabolism process and calculating Bottle $BOD_5$ were added and the results of proposed model were compared to those of the original SWAT model. The results of comparison test are showing that more accurate BOD values can be obtained with the Q-SWAT model and it is anticipated that the Q-SWAT model can be used as an effective tool of decision support through the water quality simulation and long term pollution source analysis.

• 박물관보존과학
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• 제21권
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• pp.53-66
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• 2019

본 연구는 강원도 영월 하송리 유적에서 출토된 금속유물의 보존처리 과정과 표면성분분석 결과를 제시하였다. 금동소형풍탁 1점, 풍설 2점, 호리병 형태 소형 청동병 1점을 대상으로 XRF를 이용한 표면 성분분석을 진행하였고, 호리병 형태 소형청동병은 X-ray를 통한 내부구조관찰을 실시하였다. 금동소형풍탁과 풍설은 같은 위치에서 출토되었으나, 금동소형풍탁은 도금층이 확인되는데 반해, 풍설은 부식층이 표면에 고착되어 가시적으로 확인되지 않았다. 분석결과 금동소형풍탁은 Cu-Sn-Pb 3원계 합금 청동소지에 Au를 수은 아말감으로 도금하여 제작하였음을 확인하였다. 풍설은 소지가 구리이며, 소량의 금성분이 검출되었다, 호리병 형태 소형 청동병은 형태적으로 비슷한 고려시대 화폐인 은병(銀甁)인지 여부를 확인하고자 표면 성분분석과 함께 X-ray 촬영을 실시하였다. X-ray 촬영 결과 저부의 가운데 부분에 작은 구멍을 막았던 것으로 보이는 흔적이 확인되었으며, 전체적인 표면분석 결과에서는 은이 검출되지 않아 은병이 아닌 청동유물임을 알 수 있었다.

• 한국식생활문화학회지
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• 제1권2호
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• pp.171-176
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• 1986

The drinking manners of the modern generaton were reviewed based on historical records. First, for reasons of health, we should reject the drinking from the same cup as others in reciprocation. Second, if the other people are older or younger brothers above the same level, pouring with one hand is all right, but if 5 years older or more, or stranger, grasp the bottle in two hands in the following manner. With the right hand under the bottle, and the left hand supporting its side, carefully pour wine not to show the palm of the hand. Third, ladies, also, can drink freely at the same table, but if people of the opposite sex are sitting together, they should pour with two hands to convey the meaning of courteous treatment. Fourth, because the level of our living is not two high, we must not order more them we can use, so that when we are finished, there will be no remainder.

• 한국통신학회논문지
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• 제27권4C호
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• pp.365-370
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• 2002

본 논문에서는 외부 영상에서 다중 처리된 디지털 신호를 PCI로 전송할 수 있는 시스템을 설계하였다. CPU와 주변기기들의 전송율 제한에 따른 병목 현상을 개선한 것으로 실시간으로 처리되는 영상 데이터에 대하여 효율적으로 전송 및 제어할 수 있는 구조를 제안하였다. 또한 PCI로 빠른 데이터 전송 및 DMA 기능으로 자체적인 부하 사용량을 13% 줄였다. 설계는 Max+plusII를 이용한 기능 및 타이밍에 대한 동작 검증을 하였다.

• 한국CDE학회논문집
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• 제10권5호
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• pp.365-374
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• 2005

Most of people who are engaged in research and development find it difficult to solve the engineering problems creatively due to the lack of ideas. TRIZ is one of the emerging problem solving techniques that leads us to a very useful and clear solution. TRIZ consists of several tools such as ideal final result (IFR), physical and technical contradictions, 40 invention principles, resource, effect, etc. However, many designers think that TRIZ is hard to be applied to a design problem since there are several tools in TRIZ. Machine designers may want to see which tool is more effective than others. Thus, this paper provides sample solutions of a design problem: holder design for the bottle etching machine by applying several TRIZ tools. Difficulties in applying TRIZ to a design problem are discussed.

• 한국산업보건학회지
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• 제7권2호
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• pp.209-222
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• 1997

Authors surveyed the ground water near the waste disposed from a fiberglass production factory to confirm the presence of glassfiber in the water and to determine the effect of sampling conditions and storage on the recovery of fibrous materials in the ground water. Sample was collected at every 4 hours for 48 hours consecutively. After finishing the 48 hours sample, water sampling was done from each tap after repeated turning on and off the water for 30 seconds at each time. Sample was collected in the two 1.5 liter polyethylene bottle after vigorously shaking the bottle with the same water several times with the flowing tap water. At each paired sample, one bottle was stored stand still at room temperature, and the other sample was filtered immediately after sampling. Water was filtered on the Mixed Cellulose Ester filter with negative pressure. Each sample was divided into upper and lower layer. The other bottle was stored at room temperature standstill for 7 days and filtered in the same fashion as the other pair of sample did. Each MCE filter was divided into 4 pieces and one piece was treated with acetone to make it transparent. Each prepared sample was observed by two researchers under the light and polarizing microscopy, scanning electron microscopy and energy dispersive X-ra microanalysis. Fibers were classified by the morphology and polarizing pattern under the polarizing microscope, and count was done. 1. There was a significant fluctuation in number of the fibers, but there was no specific demonstrable pattern. 2. Non-polarizing fibers frequently disappeared after 7 days's storage. But cluster of fibers were found at the wall of the same container by scratching technique. 3. Polarizing fibers were usually found in between the filter and the manicure pasted area. Possible explanations for this phenomenon will be that either these fibers are very light or have electronic polarity. Hence, these fibers are not able to be attached on the surface of slide glass. 4. Under the scanning electron microscopic examination, the fibers which are not refractive under the light microscopy were identified as glassfiber. Other fibers which is refractive under the polarizing microscopy were identified as magnesium silicate fibers. It is strongly suggested that development of standardized method of sample collection and measurement of fibrous material in the water is needed.