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)

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.

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.

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.

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.

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)

전기응집에 의한 도금폐수 처리의 최적화

이찬원,양기섭,윤재일,박영배 경남대학교 환경문제연구소 1998 환경연구 Vol.21 No.-

The zinc containing wastewater from the metal finishing industry was treated by electro-coagulation system. The zine was effectively removed with removal efficiency ranging from 95 to 99%. The operation of the system was conducted to find out the optimum conditions to reduce bleaching out effect from plate, changing important parameters such as reactor plate select, flow rate, pass, amperage and settling time, along with a consideration of O&M costs for the electro-coagulation system. The most effective and economical conditions was concluded to be a combination of Fe plate 1.0 L/min of flow rate, 5 pass, 15 amperage and 30 min settling. The copper plating wastewater was also effectively treated with 94% removal effectively under this optimum condition.

Continuous Wave of Condensation Technique으로 근관충전시 치근면 온도상승 분석

김영주,황윤찬,김선호,황인남,최보영,정영진,정우남,오원만 大韓齒科保存學會 2003 Restorative Dentistry & Endodontics Vol.28 No.4

This study was conducted to evaluate the temperature rise on the root surface while the root canal is being obturated using continuous wave of condensation technique. Maxillary central incisor was prepared for repeated canal obturation. Ten thermocouples (Omega Engineering Inc., Stanford, USA) were placed at 1mm increment from the anatomical root apex. The real temperature of Buchanan plugger was recorded before insertion into the root canal. The root canal was obturated with continuous wave of condensation technique as described by Buchanan and the root surface temperature was recorded during obturation at 150℃, 200℃, 250℃ and 300℃ temperature settings of System B HeatSource (Model 1005, Analytic technologies, Redmond, WA, USA). After completion of the temperature recording, the dentinal-cementum thickness at each sites was measured. The data were analyzed using one-way ANOVA followed by Scheffe's test and linear regression test. The results were as follows. 1. When the temperature was set at 150℃, 200℃, 250℃ and 300℃ on the digital display of System B HeatSource, the real temperature of the plugger at the 1mm point from the tip revealed 130.82±2.96℃ 158.00±5.26℃, 215.93±6.91℃ and 249.88±3.65℃ respectively. 2. The position of 8 mm from the anatomical apex showed the highest temperature increase at each temperature settings and it was significantly higher than those of other positions (p<0.01). The temperature rise was constantly increased toward coronal portion from apex of the root. 3. The maximum temperature increase on the root surface was 2.37±0.09℃ at 150℃ setting, 3.11±0.12℃ at 200℃ setting, 3.93±0.09℃ at 250℃ setting and 5.69±0.15℃ at 300℃ setting respectively. These results suggest that it be relatively kind to the supporting tissues of the root that the root canal is obturated using continuous wave of condensation technique at 150℃, 200℃, 250℃ and 300℃ temperature settings on digital temperature display of System B HeatSource.

Frozen Shoulder에 있어서 마사지의 치료적 접근

홍성찬,김영빈,박병근,정동혁,이정윤,이동헌 圓光大學校 附設 體力科學硏究所 2003 體力科學硏究 Vol.26 No.1

Painful stiffness of the shoulder is an ill-defined clinical entity that is difficult to assess and delicate to treat. The nomenclature used is broad and includes terms such as frozen shoulder, adhesive capsulitis, focal algodystrophy, stiff shoulder, contracted shoulder, and others. Apart from its idiopathic form, the disease can be initiated by trauma, infection, tumour, radiation, systemic and local metabolic disturbances. Pathoanatomically, the common denominator is an inflammatory vascular proliferation followed by thickening, scarring, and retraction of the joint capsule. The inflammatory process often starts at the rotator interval and may extend to the subacromial space. Clinical diagnosis is based on history and physical examination. Generally the onset of pain precedes the perception of a reduced range of motion by weeks or months. In early stages of the disease, the inflammatory type of pain dominates, i.e., the patient's main complaint ist pain at night. In the later stage, range of motion gradually decreases. Patients do not often complain about reduced motion, probably because of its slow onset. The purpose of this study is to find out the effectiveness of the massage applied to the patients with Frozen Shoulder by measuring, assessing and analyzing the changes in intensity and unpleasantness of pain and range of motion(ROM) before and after massage. Surveyed from Jan. 2001 to December 2002 were 104 patients suffering from Frozen Shoulder. In the therapeutic massage program, such methods as Effleurage, Petrissage and Deep transverse friction were selected as they are among traditional massage treatments frequently used for joints with pain and restricted ROM. Effleurage and Petrissage were applied for 20 minutes in total before and after Deep Transverse Friction. After massage program, the intensity and unpleasantness of pain were measured and analyzed by means of VAS(visual analogue scale)-I and VAS-U, while ROM was measured and analyzed by using Goniometer. The major findings from this study are as follows; 1. The surveyed patients range from 28 to 75 in age, with highest numbers of 44(42.31%) registered in the fifties and next ones of 24(23.08%) in the forties. Divided by sex, 59 are women and 45 are men totalling 104 with average age of 51.4. 2. There was significant decrease in the intensity of pain and unpleasantness of pain after massage(p<.05). 3. There appeared, however, significant increase in ROM after massage(p<.05). 4. From the analysis into chronological changes in ROM before and after massage with ANOVA, it became evident that the longer the period of treatment was, the higher the ROM increases drastically, while significant difference was shown in Abduction and in External and Internal Rotation(p<.05). Summed up, it can be generally concluded that massage is an effective treatment to rid the patients with Frozen Shoulder of pains safely and promptly. This study was conducted to determine more accurate impact of massage. From the above outcomes, it was revealed that massage has proven to reduce the pains, exercising huge influence to increase ROM. It is, therefore, suggested to continue and expand the study on the cure of Frozen Shoulder and to motivate patients, orthopedists, physiatrists, physiotherapists, and sports massagists etc. to consider massage as safest and most efficient pain remedy.

백반증 병변에 국한되어 발생한 건선 1예

김윤전,강희영,이은소,김유찬 대한피부과학회 2006 대한피부과학회지 Vol.44 No.4