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.

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.

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.

유사한 전자상태를 가지는 타이타늄 합금의 영률에 베타 안정화 원소 함량이 미치는 영향

유가영 ( Ga Young Yoo ),박찬희 ( Chan Hee Park ),홍재근 ( Jae Keun Hong ),김승언 ( Seong Eun Kim ),강남현 ( Seong Eun Kim ),염종택 ( Jong Taek Yeom ) 대한금속재료학회(구 대한금속학회) 2013 대한금속·재료학회지 Vol.51 No.4

Previously, Gum Metal (Ti-24(Nb + Ta + V)-(Zr, Hf)-O (at%)) exhibiting an ultralow Young`s modulus, ultrahigh strength and super elasticity was developed by Saito et al., who proposed that three electronic magic numbers, an average electron/atom (e/a) ratio of 4.24, an average bond order (Bo) of about 2.87, and an average “d” electron-orbital energy level (Md) of about 2.45 eV, should be satisfied simultaneously to obtain such “super” properties. The purpose of this study was to find new alloy systems possessing those properties and to examine the effect of beta equivalent content ([Mo]eq) on Young`s moduli of new alloys having the same three electronic numbers mentioned above. It was found that not only three electronic numbers but also [Mo]eq should be considered to obtain a similar Young`s modulus and hardness with respect to the Gum Metal.

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.

가정과 교육실습 프로그램 운영 개선에 대한 사례 연구

유태명,안영희,이송자 한국 가정과 교육 학회 1998 한국가정과교육학회지 Vol.10 No.1

This study employs a case study method to examine the current implementation of student teaching program in a particular teacher education institution and its affilated school. The purpose ofthis sutdy is to improve the quality ofhome economics student teaching proghram by promoting collaboration of teacher education institution and host schools. Following five research problems are addressed: (1) Examining the problems ofstudent teaching from the literature review; (2) Identifying the problems of student teaching recognized by home economics student teachers; (3) Identifying the problems of student teaching and plans for improvements suggested in the seminar held for home economics teacher; (4) Analyzing and comparing the differences of opinion between home economics student teachers and student teaching cooperating home economics teachers on the student teaching program; and (5) Suggesting alternative implementation plans for improving student teaching program by promoting collaboration of teacher education institution and host schools.

茶 CATECHIN 成分의 生體 調節 作用에 關한 考察

劉永祥,鄭姬貞 동국대학교 대학원 1993 大學院硏究論集-東國大學校 大學院 Vol.23 No.-

The major components of tea are (+)Catechin, (-) Epicatechin(EC), (-)Epicatechin(EC), (+)Gallocatechin, (-)Epigallocatechin(EC), (-)Epicatechin gallate(ECg), (-)Epigallocatechin gallate(EGCg), the content of catechins in tea is about 30% on dry basis. There are many hydroxy groups in tea catechins. The Catechines are used as food antioxidants because of oxidization od them. the catechins, especially ECg and EGCg are main components that are responsible for the biological action of tea. Tea catechins have lots of the pharmacological effects. This are hypertension-depressing action, hypocholesterolemic effect, anti-obesity effect and anticarcinogenic and antimutagenic effect. In the future, the more research of the more effect on peroxidized lipid in tea catechins will be needed.

모발의 부위별 분석을 통한 Methamphetamine 남용자의 복용시기 추정에 관하여

유영찬,정희선,최화경,진원택,이한선 內務部 國立科學搜査硏究所 1996 國立 科學 搜査 硏究所 年報 Vol.28 No.-

PC Beam 교량의 진동 특성에 관한 연구

유희중,윤영균 호남대학교산업기술연구소 2011 산업기술연구논문집 Vol.17 No.-

본 연구는 실제 교량(PC Beam)에서 재하시험을 통해 교량의 고유진동수를 진동모드별로 파악한 후, 수치 모델링을 통하여 유도된 동적하중에 따른 6차 모드까지의 고유진동수를 고려하여 처짐을 계산할 수 있는 산정식에 관한 것이다. 처짐 계산식은 모드중첩법에 의한 비감쇠 강제진동 이론을 이용하여 교량을 등속도로 이동하는 동적 주행하중에 의해 발생하는 처짐을 계산할 수 있도록 수치 모델링을 하였으며, 이를 검증하고 자동으로 계산할 수 있도록 하였다. 그리고 제안된 처짐 계산식을 검증하기 위하여 PC Beam 교량을 대상으로 동적재하시험을 실시하여 처짐을 측정하고 이 값을 본 연구의 처짐 계산식의 결과와 비교하였다. 이 결과, 본 연구에서 제안하는 처짐 계산식은 고유진동수를 고려하는 진동모드의 차수가 낮은 경우에 비교적 정확한 처짐을 예측하며, 주행속도에 따라서는 적용하는 진동모드 차수에 의하여 처짐 예측의 정확도가 영향을 받는 것을 확인하였다. This research bridges the actual (PC Beam) through the loading test on the bridge identified by the resonant frequency of vibration mode, and then through numerical modeling based on dynamic loads induced through the sixth mode, the resonant frequency can be calculated by considering deflection estimate is about expression. Deflection due to the calculation mode superposition theory bigamsoe forced vibration of the bridge to move the dynamic driving force constant velocity caused by the deflection to be calculated with numerical modeling was validated and it was so that it can be evaluated automatically. And, in order to validate the proposed equation of deflection against PC Beam Bridge dynamic loading test conducted to measure the deflection of the deflection of this study, these values ​​were compared with the results of calculations. As a result, the deflection equation proposed in this study to consider the natural frequency of vibration mode, a relatively low degree, predict the correct sag, depending on driving speed in order to apply the vibration mode is affected by the accuracy of predictions of deflection were to receive.