고려․조선전기 한일관계사 기술의 공통점과 차이점

손승철(Son, Seung?Cheul) 한일관계사학회 2006 한일관계사연구 Vol.25 No.-

인듀서 내부의 캐비테이션 유동과 흡입성능에 관한 연구

申澈洙,金鍾喆,姜宇政,李先基 충주대 산업과학기술연구소 1995 産業科學論文集 Vol.3 No.-

In order to understand the influence of the inducer inlet angle on cavitation and suction performance, experiments were carried out for two kinds inducer, which have the same outlet angle distribution, length and number of inducer blades. The results showed that the change of inducer inlet angles influenced not only internal flow conditions but also cavity flow and suction performance. The improvement of suction performance by using inducer were also discussed.

상아질에 적용된 재 습윤제가 미세인장 결합강도에 미치는 영향

강희영,조영곤,김종욱,박병철,유상훈,진철희,최희영,기영재 大韓齒科保存學會 2004 Restorative Dentistry & Endodontics Vol.29 No.2

This study investigated that the effect of rewetting agent on dentinal microtensile bond strength (μTBS). Human molars were sectioned to expose the superficial dentin surfaces. Samples were divided into two groups according to type of adhesives-Single Bond (S) and One-Step (0)], and again subdivided into five groups by different dentin surface treatment-dry for 15s (D) , blot dry (BD) or dry for 15s, and rewet with different rewetting agents[distil1ed water (DW), Gluma Desensitizer (GD) and Aqua-Prep (AP)]for 30s. After application of adhesive, composite resin was built up on the bonding surface. Each tooth was sectioned to obtain stick with 1mm^(2) cross sectional area and the μTBS was determined by EZ test. In the S group, the mean μTBS of GD, AP and BD group was significantly higher than that of DW and D group (p < 0.05). In the 0 group, the mean μTBS of AP, GD, BD and DW group was significantly higher than that of D group (p < 0.05). The data suggested that Gluma Desensitizer and Aqua-Prep could be successfully used as rewetting agents, and Distilled water could be acceptable in aceton based adhesive system only.

법랑질 접착에 대한 습윤 효과

고근호,조영곤,진철희,유상훈,김종욱,박병철,기영재,최희영,김종진 大韓齒科保存學會 2004 Restorative Dentistry & Endodontics Vol.29 No.3

This study evaluated the microleakage and interfacial gap between enamel and composite resin under the dry and wet condition of the enamel surface, V shaped class 5 cavities were prepared on the occlusal portion of extracted human molars. Samples were divided into three groups: D group (air dry for 10-15s), BD group (blot dry with moist cotton pellet), and DR group (air dry for 10-15s and rewet with Aqua-Prep F for 20s). Cavities were filled using Aelitefil composite resin after applied One-Step. Microleakage was tested by 2% methylene blue dye solution and the data were statistically analysed by Kruskal-Wallis test and Mann-Whitney test. Also Enamel-resin interface was observed under SEM. Group BD showed statistically lower microleakage than group D (p〈0.05). but there was no statistically significant difference between group BD and DR (p)0.05). At the enamel-resin interface, group D showed the gap of 2 ㎛ thickness, but group BD and DR showed close adaptation. In conclusion, the use of blot dry and rewetting agent (Aqua-Prep F) resulted in decreased microleakage and improved adhesion between enamel and resin when using One-Step.

복합레진의 지연충전이 미세인장 결합강도에 미치는 영향

박현식,조영곤,박병철,김종욱,최희영,김종진,진철희,유상훈,기영재 大韓齒科保存學會 2004 Restorative Dentistry & Endodontics Vol.29 No.3

The purpose of this study was to evaluate the effect of immediate or delayed composite resin filling on dentinal microtensile bond strength (μTBS) after applied the adhesive. The coronal dentin of human third molars was exposed. Single-Bond or One-Step was applied on the dentin surfaces, and composite resin were constructed immediately (group 1) or 5 min., 10 min., 15 min., 20 min. and 30 min. (groups 2-6) after an adhesive was applied. The specimens were sectioned and made bar-shaped. Each surface area of them was about l ㎟. The RBS test was performed by EZ test. The results were analysed by One-way ANOVA and Tukey's test at 95 % significance level. The results suggested that the μTBS of Single-Bond to dentin was decreased when the composite resin was constructed 20 min. and 30 min. after Single-Bond was applied. But the μTBS of One-Step was not affected by delayed composite resin filling.

자가 산부식 프라이머의 적용시간이 상아질의 미세인장 결합강도에 미치는 영향

조영곤,이영곤,김종욱,박병철,김종진,최희영,진철희,유상훈 大韓齒科保存學會 2004 Restorative Dentistry & Endodontics Vol.29 No.5

This study evaluated the influence of application time of self-etching primers on microtensile bond strength (μTBS) to dentin using three self-etching primer adhesive systems. Dentin surfaces were exposed from forty-eight human molars. They were conditioned with three self-etching primers (Clearfil SE Bond [SE], Unifil Bond [UF], Tyrian SPE + One Step Plus [TY]) and different primining times (10s, 20s, 30s and 40s). Composite resins were bonded to dentin surfaces and specimens were made. μTBS was tested and statistically compared using by one-way ANOVA and Tukey's Test. The results of this study presented that priming time for 10s in SE and UF groups and for 30s and 40s in TY group was highly decreased μTBS to dentin.

단일 단계 접착제의 변연 미세누출

조영곤,정진호,기영재,최희영,진철희,유상훈,김종욱,박병철 大韓齒科保存學會 2004 Restorative Dentistry & Endodontics Vol.29 No.2

This study evaluated the marginal microleakage of five single step adhesives. Class V cavity preparations with occlusal margins in enamel and gingival margins in dentin were prepared on both buccal and lingual surfaces of extracted human molar teeth. Prepared teeth were randomly divided into five groups and restored using one of the single step adhesives and composite resins: Prompt L-Pop/Filtek Z-250 (Group 1), AQ Bond/Metafil CX (Group 2), One-Up Bond F/Palfique Toughwell (Group 3), Futurabond/Admira (Group 4), Xeno III/Spectrum TPH (Group 5). The restored teeth were thermocycled. Microleakage was assessed by dye penetration using 2% methylene blue dye solution. The teeth were bisected buccolingually and evaluated for microleakage under steromicroscope. The data were statistically analysed by Kruskal-Wallis test and Mann-Whitney tests. The results of this study were as follows; 1. Microleakage of enamel margins in group 3 was statistically higher than that in groups 1, 2, 4, 5 (p < 0.05) 2. Microleakage of dentin margins in group 1 was statistically higher than that in groups 2, 5, and that in group 3 was statistically higher than that in groups 2, 4, 5 (p < 0.05). 3. Dentin marginal microleakage was higher than enamel marginal microleakage in all experimental groups. In conclusion, Prompt L-Pop showed the least leakage at enamel margin, and AQ Bond showed at dentin margin in this study. Marginal miroleakage in dentin was higher than that in enamel.

대동맥 분기부의 협착부에서의 혈액 유동 특성

신철수 한국교통대학교 2015 한국교통대학교 논문집 Vol.50 No.-

The three dimensional steady flows of blood and blood analogue fluids in the abdominal aortic bifurcation are simulated using the finite volume method. The objective of this investigation is to understand the generation and progression of specific atherosclerosis from a hydrodynamic point of view. Due to complexity of blood in conducting experimental study, aqueous polymer solution are used as the substitutional fluids. For comparison purpose of the flow characteristic of blood and substitutional fluids, rheology different fluids such as water soluble polymers of Carbopol-934 and Separan AP-273 are employed for the numerical simulation. In order to understand the role of hydrodynamic in the formation and development of atherosclerosis lesions flow velocities, pressures and shere stresses along the vessel are calculated for steady flows

3차원 모델에서의 亂流 제트유동 예측

신철수 忠州大學校 2004 한국교통대학교 논문집 Vol.39 No.1

Turbulent jet in a cross flow on the symmetric plane is predicted by a quasi 3-dimensional mathematical model. The governing equations are solved by finite analytic method and partially parabolic procedure. a low Reynolds number model is used to solve the turbulent closure problem. In the case of the velocity ratio M=0.1 there are considered to describe the downstream development from the hole and found to be in good agreement with the published experimental results by other author. The quasi 3-dimensional mathematical model has been found to be quite economical and efficient.

Cordierite 合成에 관한 硏究(I)

楊澈基,金圭鎬 嶺南大學校 工業技術硏究所 1982 연구보고 Vol.10 No.1

In order to obtain the superior refractory mineral having lower thermal expansion, cordierite was synthesized from pure reagents Al₂O₃,MgO, SiO₂. Mixtures were fired between 1,270℃ and 1,320℃ and qualitative determenation of cordierite formation was investigated X-ray diffraction analysis and polarization microscope. For the effects of impurities on the synthesis of cordierite, adding 1.5wt% Fe₂O₃and 0.5wt% K₂O₃, Na₂O to the cordierite formation. Adding 0.5wt% CaO does harmful upon the thermal expansion. In the variation of cordierite composition, Al₂O₃rich bodies approaching the theoretical composition of cordierite is superior to SiO₂MgO rich bodies on the low thermal expansion property. The bodies resintered three times are superior to bodies sintered on the low thermal expansion property.