용해실리카의 기준경도를 이용한 나노 압입시스템의 실험적 교정

이윤희 ( Yun Hee Lee ),안승민 ( Seung Min Ahn ),김주영 ( Ju Young Kim ),박찬평 ( Chan Pyung Park ),장희광 ( Hee Kwang Jang ) 대한금속재료학회(구 대한금속학회) 2015 대한금속·재료학회지 Vol.53 No.3

Indirect calibration of a nanoindentation system was performed by deriving a reference loading curve. This reference load-depth relationship was accomplished by assuming a perfect nanoindentation test on an ideal reference material; if all components in a nanoindentation system are well calibrated and the reference material has unique hardness and Young’s modulus, the indentation depth can be formulated with a function of the indentation load having two parts of contact and surrounding elastic depths. Substituting both the hardness and Young’s modulus of a fused silica into the derived function, the reference loading curve was plotted and directly compared with experimental data of the fused silica measured by two commercial nanoindenters. All indentation loading curves showed leftward shifts compared to the reference loading curve, and this is discussed, offering two reasons for the result, system compliance and indenter apex geometry.(Received January 6, 2014)

수냉쿨러의 냉각 효율 향상을 위한 플레이트 부품의 형상에 관한 연구

성윤호,김형찬,김선민,윤석영,이영웅,이상욱 순천향대학교 부설 산업기술연구소 2021 순천향 산업기술연구소논문집 Vol.27 No.2

This study investigates changes in cooling efficiency for heat sink plate width, perforated width, and chamfer angle as part of a parameter study to maximize cooling efficiency of heat sink by setting various variables on plates. The width of the plate is set to 16, 20, 24, 28 mm, perforated width 1.5, 2.0, 2.5 mm, chamfer angles 5, 10, 15 and 20°. By conducting a computational study with Ansys Fluent, the sink plate with plate width of 16mm, perforated width of 3mm and chamfer angle of 10° is shown to be the best cooling efficiency.

색상 측정 기기를 이용한 복합레진 적층 수복과 단일 수복의 색상 비교 분석

송영상,김자현,이빈나,장지현,장훈상,황윤찬,오원만,황인남 大韓齒科保存學會 2012 Restorative Dentistry & Endodontics Vol.37 No.2

Objectives: This study analyzed the difference in color caused by different thickness in enamel layer of composite resins when applied with single and layering placement technique, and evaluated if the results agreed with the shade guide from the manufacturers to verify reliability of the color matching process of the manufacturers. Materials and Methods: For single composite resin samples, 6 mm diameter and 4 mm thickness cylindrical samples were fabricated using Ceram-X mono (DENTSPLY DeTrey) and CIE L*a*b* values were measured with spectrophotometer. Same process was done for layering compositie resin samples, making 3 dentinal shade samples, 4 mm thickness, for each shade using Ceram-X duo (DENTSPLY DeTrey) and enamel shade resins were layered in 2 mm thickness and CIE L*a*b* values were measured. These samples were ground to 0.2 mm thickness each time, and CIE L*a*b* values were measured to 1 mm thickness of enamel shade resin. Results: Color difference (△E*) between single and layering composite resin was 1.37 minimum and 10.53 maximum when layering thicknesses were between 1 mm and 2 mm and 6 out of 10 same shade groups suggested by manufacturer showed remarkable color difference at anythickness (△E* > 3.3). Conclusion: When using Ceram-X mono and duo for composite resin restoration, following the manufacturer's instructions for chossing the shade is not appropriate, and more accurate information for Ceram-X duo is needed on the variation and expression of the shades depending on the thickness of the enamel. (Restor Dent Endod 2012;37(2):84-89)

금 합금 보철물의 교합면 삭제로 인한 임플란트-골 계면으로의 열전달에 관한 연구

조재영,강선녀,정창모,윤미정,허중보,전영찬 대한치과보철학회 2012 대한치과보철학회지 Vol.50 No.1

연구 목적: 임플란트-골 계면에서 발생하는 과도한 열은 골유착을 저해하여 임플란트의 실패를 유발한다. 이에 이번 연구에서는 임플란트 금 합금 보철물의 교합면 삭제시 임플란트-골 계면으로의 열전달 양상과 냉각 방식의 효율성을 알아 보고자 하였다. 연구 재료 및 방법: 온도 감지 장치 제작을 위하여 Internal cone 연결형태의 임플란트에 16개의K형 열전대를 부착하여 아크릴릭 레진에 포매하였다. 치과용 금 합금과 주조용 abutment를 사용하여 교합면에 3개의 요철을 가지는 시편을 10개 제작하였고, 연결 나사를 이용하여 임플란트와 연결한 뒤 온도 감지 장치를 37℃로 유지되는 수조에 위치시켰다. 저속 핸드피스와 green stone bur를 이용하여 30초 동안 보철물의 요철을 삭제하였는데, 무냉각군, 공기 냉각 군, 물 분사 냉각 군으로 나누어 요철을 삭제하였다. 보철물이 삭제 되는 동안 임플란트의 부위별로 온도가 0.05초 간격으로 기록되었고, 삭제를 멈춘 뒤에도 무 냉각 군의 경우 임계 온도인 47℃ 이하로 온도가 하강할 때까지, 공기 냉각군과 물 분사 냉각군의 경우 삭제 중단 후 30초 동안 추가로 온도를 기록하였다. 냉각 방식에 따른 임플란트-골 계면의 온도를 알아보고, 임플란트의 부위별 온도변화의 유의차를 알아보기 위하여 one-way ANOVA를 실시하였고, Turkey HSD 이용하여 95% 유의수준에서 사후 검증하였다. 결과: 무 냉각 군은 임플란트-골 계면의 온도가 47℃ 이상으로 상승하였으며, 임플란트의 경부에서 유의하게 높은 열이 측정되었다(P>.05). 공기냉각군과 물분사 냉각군은 임플란트-골 계면의 온도가 47℃ 이하로 유지되었다. 무 냉각 군에서 임플란트 경부의 온도가 47℃에 도달되는 데는 약 10.8 ± 1.5초가 소요되었다. 공기 냉각 군과 물 분사 냉각 군 사이에서는 임플란트-골 계면 온도의 유의차가 없었다(P>.05) 결론: 이상의 결과로부터 임플란트 금 합금 보철물의 교합면 삭제 시, 임플란트 주위 조직에 위해를 가할 수 있는 임계 온도 이상의 열이 발생했음을 알 수 있었으며, 냉각방식은 공기 냉각과 물 분사 냉각 모두 효과적이라고 생각된다. PURPOSE. The purpose of this study was to analyze temperature change along the implant-bone interface induced by grinding the occlusal surface of implant gold prosthesis and to compare the temperature generated by grinding of prosthesis with different cooling methods. MATERIALS AND METHODS. The experimental gold prostheses were fabricated with dental gold alloy and castable abutment. The prostheses had 3 cylindrical protrusions on the occlusal surface with 1mm in height. Temperature was measured using 16 thermocouple wires attached to the implant fixture surface and the fixture was embedded in an acrylic resin block inside the 37℃ water bath. Cylinders were grinded for a period of 30 second with a low-speed handpiece with green stone point. One cylindrical protrusion was grinded without cooling, the second one was grinded with air blow, and the third one was grinded with water-spray. RESULTS. The mean maximum temperature was measured more than 47℃ of the implant and the maximum temperature was measured at the cervical portion of the implant in the group without cooling. There was statistically significant difference between the group without cooling and the groups with cooling (P<.05). However, there was no significant difference at all portion of implant in the groups with cooling (P>.05). CONCLUSION. The results of this study support that the grinding of implant gold prosthesis without cooling may damage the peri-implant tissue. The continuous use of air blow and water-spray adjacent to prosthesis during the grinding of implant gold prosthesis may prove to be beneficial for cooling of the implant.

테르펜과 1,2-디메틸싸이클로펜텐의 기체상 오존화반응

윤의중,구본석,정인수,정인찬,이영훈,신혜숙 한서대학교 산학협력연구원 부설 환경연구소 2000 환경연구소 논문집 Vol.3 No.-

Gas phase Ozonolyses have been examined with particular emphasis on the question whether are produced. The following results were obtained. 1) In contrast to previous reports, Ozonolyses of the terpense β-pinene and sabinene provided the corresponding ozonides as minor products. Major products were the corresponding ketones, respectively. In addition, β-pinene afforded the lactones, while sabinene gave the lactones. 2) Ozonolyses of 1, 2-dimethylcyclopentene provided the corresponding ozonide as a minor and diketone as the major product, along with small proportions, each, of nine additional products. 3) Ozone treatment of diketone provided small amounts of Ozonide in a hitherto unprecedented reaction of diketiones with ozone.

Piracetam이 마우스의 기억력 및 대뇌피질내 Acetylcholine량 변화에 미치는 영향

尹再順,申精姬,李容筍,劉永瓚 梨花女子大學校 韓國生活科學硏究院 1991 韓國生活科學硏究院 論叢 Vol.47 No.-

The central cholinergic synapse is known to be closely connected with memory. Previously, piracetam has been reported to improve the intellectual ability. We used a scopolamine-induced amnesiac mouse to study the effects of piracetam on memory retrieval by passive avoidance learning test and on the acetylcholine level of cerebral cortex. The amnesia was produced in mouse by the intraperitoneal injection(i.p.) of scopolamine at a dose of 1 ㎎/㎏ body weight(b.w.). Upon administration of piracetam to amnesiac mouse at doses of 100 and 200 ㎎/㎏ b.w., i.p., 30 min, prior to retrieval test, the significant improvement on memory impairment was observed by examination 24 hr after training. The level of acetylcholine in cerebral cortex of mouse was decreased by the scopolamine treatment, however, this decrease was attenuated by piracetam. These results suggest that the effect of piracetam on memory may be attributed to activation of cholinergic nerve.

만성 견비통에 대한 동씨침 치료의 무작위 대조군의 임상 연구

김찬영,권나현,신예지,남동우,김건형,김종인,최도영,이윤호,이재동 WHO COLLABORATING CENTRE FOR TRADITIONAL MEDICINE 2007 東西醫學硏究所 論文集 Vol.2007 No.-

Objectives : To observe the effect of acupuncture treatment in chronic shoulder pain patients. Methods : 36 voluntary patients were randomly assigned to an acupuncture treatment group(E GrouP, n=18) and a control group(C GrouP, n=18). The E Group patients received acupuncture treatment on LI_(15), TE_(14), GB_(21) and Master Dong's acupuncture points, Shin-gwan and Gyun-joong, twice a week for four weeks. The C Group patients received no treatment. All patients in both groups were instructed to practise self exercise in their daily lives. Evaluations were made at baseline and after four weeks of study. The Constant Shoulder Assessment(CSA), Shoulder Pain and Disability Index(SPADI) and the patient's subjective pain was measured by Visual Analogue Scale(VAS). The obtained data was analyzed. Results '. The E Group showed significant(p<0.05) improvement in CSA, SPADI and VAS after four weeks of treatment. The C Group showed significant(p<0.05) improvement in CSA, but the change of SPADI and VAS was insignificant(P>0.05). CSA and SPADI of E Group significantly(p<0.05) improved compared to the C GrouP, but the difference of VAS change in the two groups was insignificant(p>0.05). Conclusions : Four weeks of acupuncture treatment significantly improved CSA, SPADI and VAS. The improvement of CSA and SPADI was significant(p<0.05) compared to untreated patients.

운동기간에 따른 혈중지단백대사 및 비만호르몬의 변화

홍성찬,함용기,김영빈,박병근,정동혁,이정윤,권성택 圓光大學校 附設 體力科學硏究所 2003 體力科學硏究 Vol.26 No.2

The purpose of this study is to elucidate the effects of regular swimming exercise on blood lipoprotein metabolism and leptin. In this study, swimming(HRmax 50-75%, 60min/day, 5day/week) was performed and 18 were participated for study during 16 weeks. They were divided into two groups, one group as experimental group(n=9) and the other as control group(n=9). A measured factors were TC, TG, HDL-C, LDL-C and leptin.. All data were expressed as mean± standard deviation by using spss package program(win 9.0), one way anova and independent t-test was used to analyze the difference of exercise duration(0week, 8week, 12week, 16week) between groups. For all statistics performed statistical significance was set at p<.05. After exercise intervention, TC, TG, HDL-C, LDL-C and leptin were found to have more significant effects in the experimental group than control group. This results indicated regular swimming exercise training is beneficial to prevent and treat cardiovascular disease and obesity.

수종의 근관세척액과 Listerine의 항균성 비교 연구

김영훈,강민경,최은경,양소영,양인석,강인철,황윤찬,황인남,오원만 대한치과보존학회 2009 Restorative Dentistry & Endodontics Vol.34 No.6

본 연구는 여러 가지 근관세척액(NaOCl, CHX, EDTA)과 구강세정제로 사용되는 Listerine을 근관감염균주인 Porphyromonas gingivalis와 Enterococcus faecalis를 상대로 항균효과를 비교하고 Listerine이 근관세척액으로 사용가능한지를 확인하고자 시행하였다. 본 연구에서는 Porphyromonas gingivalis ATCC 3327과 Enterococcus faecalis ATCC 29212의 표준균주를 사용하였다. 실험을 위한 근관세척제로 0.1%, 0.2%, 1%, 2% Chlorhexidine(CHX)과 0.5%, 1%, 2.5%, 5.25% NaOCl, 0.5M EDTA(18.6% EDTA). 그리고 Listerine원액을 이용하였다. 항균효과의 비교는 액체배지상에서 균주의 혼탁도와 한천 확산법을 이용한 억제대 비교로 하였다. 모든 실험군은 대조군과 비교시 근관내 균주에 항균성을 나타냈다(p < 0.001). 모든 농도의 NaOCl, CHX, 그리고 EDTA는 실험균주에서 높은 항균성을 보였다. 모든 실험에서 Listerine은 다른 근관세척제에 비해 낮은 항균성을 보였다. 결론적으로, Listerine이 E. faecalis와 P. gingivalis에 대해 항균성을 보이나, 일반적으로 사용되는 근관세척 액에 비해서는 현저히 낮은 항균성을 나타냄으로 근관세척 액으로 사용은 적합하지 않음을 나타냈다. The purpose of this study is to compare the antibacterial effect of Listerine on two microorganisms (P. gingivalis and E. faecalis) with various root canal irrigants (NaOCl, CHX, EDTA) and to identify possibility of using Listerine as a root canal irrigant. Porphyromonas gingivalis ATCC 3327 and Enterococcus faecalis ATCC 29212 were used in this experiment. For the test irrigants, 0.5%, 1%, 2.5%, 5.25% NaOCl, 0.1%, 0.2%, 1%, 2% CHX, 0.5M EDTA (18.6% EDTA) and Listerine were prepared. Distiled water was used as control. Two methods-1) Comparison of turbidity in broth and 2) Agar diffusion test-were used to determine the extent of antibacterial effect of Listerine and to compare it with that of NaOCl, CHX, and EDTA. All solutions tested were effective against two bacterial strains compared with control (p < 0.001). Any concentration of NaOCl, CHX, and EDTA showed similarly high effectiveness against all bacterial strains. In all experiment, Listerine showed significantly low antibacterial effect compared with the other root canal irrigants (p < 0.05). In conclusion, the results reflect remarkably low antibacterial effect of Listerine as compared with root canal irrigants in general so it is not suitable for the root canal irrigant.

수리된 복합레진 수복물의 전달결합강도 연구

최수영,정선와,황윤찬,김선호,윤창,오원만,황인남 大韓齒科保存學會 2002 Restorative Dentistry & Endodontics Vol.27 No.6

This study was performed to evaluate the interfacial shear bond strength of base (direct and indirect) and repair composites with aging and surface treatment methods. Direct composites resin specimens (Charisma®, Heraeus Kulzer, Germany) were aged for 5 min, 1 hour, 24 hours, and 1 week in 37℃ distilled water before surface treatment, and then divided into five groups: Group 1, grinding; Group 2, grinding and application of bonding agent; Group 3, grinding, etching with 37% phosphoric acid for 30sec, and application of bonding agent; Group 4, grinding, etching with 37% phosphoric acid for 30sec, silane treatment, and application of bonding agent; Group 5, grinding, etching with 4% hydrofluoric acid for 30sec, silane treatment, and application of bonding agent. Indirect composite resin specimens (Artglass®, Heraeus Kulzer, Germany) were aged for 1 week in 37℃ distilled water and divided into seven groups: Group 1 - Group 5, equal to Charisma specimens; Group 6, grinding, etching 37% phosphoric acid for 60sec, silane treatment, and application of bonding agent; Group 7, grinding, etching with 4% hydrofluoric acid for 60 sec, silane treatment, and application of bonding agent. The repair material(Charisma®) was then added on the center of the surface (5mm in diameter, 5mm in height). The shear bond strength was tested and the data was analyzed using one-way ANOVA and the Student-Newman-Keuls test. The following conclusions were drawn. 1. The shear bond strength of Charisma® specimens aged for 1 hour was significantly higher in Group 2 and Group 5 than in Group 1 (p<0.05), and that of Charisma® specimens aged for 1 week was significantly higher in Group 3 and Group 5 than in Group 1 (p<0.05). No significant difference was found in the bond strength of specimens aged for 5 min and 24 hours. 2. In Group 2 of the Charisma® specimens, there was significant difference between the bond strength of 24 hours and that of 1 week (p<0.05). 3. In Group 4 of the Charisma® specimens, the shear bond strength of specimens aged for 24 hours was significantly higher than the others(p<0.05). 4. There was no significant diiference between the shear bond strength of the Artglass® specimens. 5. Most of the Charisma® specimens showed cohesive fractures. Artglass® specimens that were etched with acid(phosphoric or hydrofluoric) for 30 sec showed more cohesive fractures.