• 대한소아치과학회지
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• 제37권1호
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• pp.82-90
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• 2010

본 연구는 불소함유 접착테잎의 법랑질 침식 예방효과를 평가하기 위해건강한 소의 치아를 절단하여 아크릴 주형에 매몰하고 정중선에 홈을 형성하여 대조면과 불소 제제를 도포할 실혐면으로 나누었다. 시편을 무작위로 18개씩 4군으로 나누었다. 1군은 APF gel를 도포하고, 2군은 불소 바니쉬를 도포하였으며, 3군과 4군은 5% NaF를 각각 첨가한 methyl cellulose와 poly vinyl alcohol 테잎을 부착하였다. 시편을 콜라에 5분, 증류수에 10분씩 6회 번갈아 처리하며 5일 동안 반복하였다. 시간 경과에 따라 표면미세경도를 측정하고 5일후 각 시편을 절단하여 침식병소의 깊이를 측정하여 다음과 같은 결과를 얻었다. 1. 표면미세경도 값은 5일째만 제외하고 2군, 3군, 4군의 실험면이 각각의 대조면에 비해 컸다 (p<0.05). 2군, 3군, 4군의 실험면 역시 5일째만 제외하고 1군의 실험면에 비해 표면미세경도가 컸다 (p<0.05). 3군과 4군 사이에는 표면미세 경도의 유의한 차이가 없었다(p>0.05). 1군의 실험면과 대조면은 표면미세경도의 유의차가 없었다(p>0.05). 2. 침식병소의 깊이는 2군, 3군, 4군의 실험면이 각각의 대조면에 비해 컸다(p<0.05). 2군, 3군, 4군의 실험면은 1군의 실험면에 비해 침식병소의 깊이가 얕았다 (p<0.05). 2군, 3군, 4군의 실험면 사이의 침식병소의 깊이는 유의차가 없었다(p>0.05). 상기 결과로 보아 새로 개발된 불소함유 접착테잎은 기존의 불소 바니쉬와 같은 법랑질 침식 예방효과가 분명하게 나타나, 법랑질 침식에 감수성이 높은 어린이 환자에게 임상적인 예방법으로서 활용할 수 있는 가능성이 높다고 사료된다.

• 한국융합학회논문지
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• 제8권6호
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• pp.139-145
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• 2017

본 연구는 우치의 인공우식법랑질에 대한 불소도포 후 재광화 효과를 공초점레이저주사현미경을 통해 비교하고자 진행되었다. 시편에 인공우식을 형성한 후, 대조군, 1.23% APF 겔 도포군, 그리고 5% NaF 바니쉬 도포군으로 구성하여 실험을 진행하였으며, 불소도포 전후의 양상은 CLSM을 이용하여 평균형광강도로 확인하였다. 불소도포 전 후 평균형광강도는 모든 군에서 유의하게 감소하는 양상을 보였으나, 평균형광강도변화량은 실험군간의 통계적으로 유의한 차이는 발견되지 않았다(p=0.222). 탈회된 표면의 표면미세경도와 평균형광강도 간에는 음의 상관관계를 보였고(p=0.941), 탈회표면의 평균형광강도가 클수록 불소도포 1일 경과 후 평균형광강도 증가하는 양의 상관관계를 보였다(r=0.811, p<0.001). 차 후 구강 내 환경을 반영한 모델이나 실제 in-situ 또는 임상실험을 통해 불소도포제제의 재광화 양상에 대한 연구가 필요할 것이다.

• Restorative Dentistry and Endodontics
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• 제34권4호
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• pp.371-376
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• 2009

이 연구에서는 Mineral Trioxide Aggregate (MTA)와 4-methacryloxyethyl trimellitate anhydride (4-META) / methyl methacrylate (MMA) & tri-n-butylborane (TBB) 레진을 혼합하여 치근단 역충전 재료로 사용하였을 때의 미세누출을 MTA, 포틀랜드 시멘트와 비교하였다. 발치된 사람 치아의 근관형성 및 충전 후 치근단 절제와 역충전 와동을 형성하였다. MTA, Portland cement, MTA와 4-META/MMA & TBB레진을 혼합한 각각의 재료로 치근단을 역충전한 후 methylene blue dye에 72시간 동안 침적하여 염료가 침투한 길이를 10배 현미경 하에서 측정하였다. MTA와 4-META/MMA & TBB 레진 혼합 충전 군에서는 포틀랜드 시멘트나 MTA 충전군보다 통계적으로 유의하게 적은 미세 누출을 보였으며, 포틀랜드 시멘트와 MTA 충전군의 미세 누출 정도는 통계적으로 차이가 없었다. 이 실험의 결과로 보아 MTA와 4-META/MMA & TBB레진 혼합 재료는 치근단 역충전시 포틀랜드 시멘트나 MTA에 비해 낮은 초기 미세누출을 보여, 치근단 봉쇄 효과가 우수한 것으로 사료된다.

• Elastomers and Composites
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• 제29권3호
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• pp.207-212
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• 1994

Recently, the develpment of waterproof techniques has been required in morden building field. It is undoubt that one of the best materials for waterproof is polyurethane. Polyurethanes have advantages such as good adhesive ability, durability, weatherproof. However, they have disadvantages like high cost, delicate varnish layer, swelling problem. In this study, we found that the polyurethane with rubber particle of waste tire can solve those problems. We concluded that 10% of rubber particles containing polyurethane was recommened as the waterproof materials.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
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• pp.313-316
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• 2003

Investigated about topology of each component of transformer and material choice method and property in this paper. Component of transformer is bobin, winding, insulating paper, Varnish etc. And, experiment and investigated special quality by primary winding of transformer and composition of secondary winding. Investigated loss of transformer and EMI decrease method. Investigated method to select winding size that consider frequency.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 C
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• pp.1601-1603
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• 2003

Investigated about topology of each component of transformer and material choice method and property in this paper. Component of transformer is bobin winding, insulating paper, Varnish etc. And experiment and investigated special quality by primary winding of transformer and composition of secondary winding. Investigated loss of transformer and EMI decrease method. Investigated method to select winding size that consider frequency.

• Restorative Dentistry and Endodontics
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• 제27권4호
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• pp.389-393
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• 2002

The marginal integrity of the crown can be broken during endodontic access cavity preparation due to the vibration of burs. Therefore, the purpose of this study was to evaluate the effect of endodontic access cavity preparation on the marginal leakage of full veneer gold crowns. 24 intact molars were mounted in acrylic resin blocks and prepared for crowns by a restorative dentist and crowns were cast with gold alloy. 20 Crowns were cemented with glass ionomer cement and 2 crowns were not cemented for positive control. 200 thermo-cycles from 5$^{\circ}C$ to 5$0^{\circ}C$ with a travel time of 20s were completed. Then samples were randomly divided into 2 experimental groups of 9 each. Endodontic access preparation and zinc-oxide eugenol temporary fillings were done in Group 1. Teeth in Group 2 were not treated. Samples were coated with 2 layers of nail varnish and were immersed in 1% methylene blue dye for 20 hrs. Endodontic access was prepared in 2 samples, which were coated with nail varnish on all surfaces for negative control. After washing in running water gold crowns were cut with a #330 bur. Four buccolingual sections, 2 mm apart, were cut from the central section of each tooth and were examined and scored under the microscope for dye leakage. Score 1: leakage to the cervical 1/3 of the axial wall, Score 2: leakage to the middle 1/3 of the axial wall, Score 3: leakage to the coronal 1/3 of the axial wall, Score 4: leakage to the occlusal surface. The median value for Group 1 is 4 and for Group 2 is 2. The result of this study showed that samples in Group 1 leaked more than those in Group 2. This finding was significant(P<0.001).

• 한국가구학회지
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• 제27권4호
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• pp.335-342
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• 2016

In previous study, volatile organic compounds (VOCs) emission characteristics were highly affected by coating materials for wood finishing. Natural based coating materials showed that about 15~46% lower TVOC emission than typical products. In this study, long-term changes of VOCs emission characteristics from pine panel with three types of coating treatments were determined. Non-treated pine panel emitted $604.7{\mu}g/m^2{\cdot}h$ of TVOC that contained 66% of NVOC ($399.7{\mu}g/m^2{\cdot}h$) at 0 month. After 10 month, TVOC reduced 88% and 93% reduction on NVOC was observed. Natural oil and waterborne stain treated pine panel showed 61% and 77% lower TVOC, respectively, than non-treated pine panel. However, TVOC from finished pine panels showed higher TVOC emission than non-treated pine panel. All samples satisfied the VOC emission regulation (below $4,000{\mu}g/m^2{\cdot}h$) by Korean Ministry of Environment. Toluene emission regulation (below $80{\mu}g/m^2{\cdot}h$) was passed on all sample without varnish treated pine panel at 0 month. According to HB qualification standard for construction materials by Korea Air Cleaning Association (KACA), wood is not qualified to get the best tag due to high TVOC emission. At the 10 months, only non-treated pine panel could get the best tag of HB from KACA.

• Journal of the Korean Wood Science and Technology
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• 제46권1호
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• pp.1-9
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• 2018

칠기문화재 보존에 옻칠이 사용되지만 근대화로 인해 캐슈칠과 같은 합성도료가 같이 사용되는 추세이다. 보존윤리에서는 문화재 보존 시 동일 재료가 사용되어야 한다고 명시되어있다. 따라서 칠기문화재 보존에는 옻칠과 같은 천연 도료가 사용되어야 한다. 하지만 옻칠과 캐슈칠의 성분이 유사하여 전문가들도 쉽게 구분하지 못하는 실정이다. 본 연구에서는 IR과 Py-GC/MS를 이용하여 이를 분석하고 식별 키워드를 찾고자 하였다. IR 분석 결과 옻칠은 $720cm^{-1}$ 대에서 피크가 확인되었으며 캐슈칠은 $750cm^{-1}$, $720cm^{-1}$, $700cm^{-1}$ 대에서 피크가 확인되었다. Py-GC/MS 결과 두 종류의 시료에서 Benzene과 Phenol계 화합물과 알킬사슬고리에 기인하는 성분이 검출되었다. 하지만, 캐슈칠에서는 Hexanoic acid라는 성분이 검출되었고 옻칠에서는 검출되지 않았다. 이러한 분석방법을 토대로 진정성 있는 칠기문화재 보존처리 및 복원에 활용될 수 있을 것이라 판단된다.

• 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.