http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
불소적용시 법랑질과 상아질에서 불화칼슘형성의 차이에 관한 실험적 연구
김재곤,권선자,윤현두,안수현,백병주 大韓小兒齒科學會 1998 大韓小兒齒科學會誌 Vol.25 No.1
The purpose of this study was to compare the amount of calcium fluoride deposited on the enamel and dentin surface and to obtain information on the morphological change and crystallographic details of mineral deposition after 12,000ppm APF application in vitro. The bovine enamel and dentin blocks were randomly assigned to eight groups according to artificial caries lesion formation and difference of fluoride application time. The fluoride concentration and morphological characteristics on the treated enamel and dentin surface were investigated by using fluoride quantitative analysis and SEM. The powdered enamel and dentin of the intact bovine incisors were prepared for the X-ray diffraction analysis. The following results were obtained. 1. The amounts of KOH-soluble fluoride on the carious enamel and dentin surface after 24h APF application were higher than after only 5min APF application(P<0.05), but in the case of the sound enamel and dentin surface were similar after 5min and 24h application (P>0.05). The fluoride content was highly increased in the carious dentin as compared with sound dentin after APF application(P<0.05). 2. The caruous enamel surface after APF application, the demineralized enamel surface were recovered a more dense enamel surface and precipitation of crystal was observed a distintive surface layer of spherical globules of about 1 m diameter. In the case of the fluorided carious dentin surface, precipitation of calcium fluoride-like material was deposited both inside the dentinal tubules as well as in the intertubular regions. 3. The crystallographic structure of powdered enamel and dentin after 24h APF application had large crystallities of apatite and CaF2 diffraction peaks in the enamel as compared with dentin. The diffraction data collected from the 27.50-29.50(2) angular range of the powdered enamel, the (105) apatite, (225) apatite and (111) CaF2 peaks of the enamel crystallities were detected after 24h APF application.
불소함유여부에 따른 치면열구전색제의 전단결합강도에 관한 실험적 연구
백병주,김재곤,허선,권선자 大韓小兒齒科學會 1996 大韓小兒齒科學會誌 Vol.23 No.2
This study was to evaluate shear bond strength fluoride-relesing sealant and nonfluoride-relesing sealant to enamel surface of bovine tooth. 80 extracted bovine teeth were randomly assigned to four groups,and four kind of sealants including Teethmate-A(Kuraray Co.),Teethmate-F(Kuraray Co.),Helioseal(Vivadent Co.),Helioseal-F(Vivadent Co.) were bonded to exposed enamel surfaces using silicon plate. Shear bond strength was determined in an instron universal testing machine at a crosshead speed of 1mm/min.Then,the fracture surfaces of test specimens were investigated with scanning electron microscope. The obtained results were as follows; 1.The shear bond strength decreased in the following oder:Teethmate-A(18.31MPa),Teethmate-F(11.90MPa),Helioseal(11.74MPa),Helioseal-F(10.64MPa). 2.The shear bond strength of Teethmate-A showed significantly higher than that of Teethmate-F(P<0.05),but Helioseal and Helioseal-F didn't showed statistically different(P<0.05). 3.According to the SEM,Teethmate-A group showed cohesive failure,and Teethmate-A group & Helioseal group showed mixed pattern of cohesive failure and Helioseal-F group showed adhesive failure.
매복 견치 및 저위교합 제 1대구치의 자가 이식에 의한 치험례
이승익,김재곤,권선자,백병주 大韓小兒齒科學會 1995 大韓小兒齒科學會誌 Vol.22 No.2
In orthodontic treatment of certain cases of tooth loss, aplasia, or ectopia, autotransplantation is sometimes valid treatment alternative often provides and improved result, compared to conventional orthodontic treatment, an apprporiate donor tooth is available and the anatomic circumstances permit it. Clinically, successful transplants must show a radiolucent space between the roots and surroundings bone. There must be no evidence of ankylosis, no permanent root resorption, and no inflammation. Histologically, the criterion of success is a normal and functional periodontal ligament between the root surfaces of transplants and the bone, or gingival connective tissues. The successful autotransplantation of a impacted maxillary canine and infraoccluded mandibular 1st molar is reported. In case Ⅰ, impacted canine with incompletely developed root apex was maintained pulp vitality due to appropriate root development and short extraoral time, atraumatic surgical procedure. In case Ⅱ, infraoccluded molar was started endodontic treatment after 3 weeks. Because of closed apex, possibility of revasculization is rare. Both case Ⅰ, Ⅱ did not ankylosis and the periodontal and periapical tissues appears to be normal after 3 months. In autotransplantation cases it is important to transplant the tooth as quickly and as atraumatically as possible to dimish the chance of ankylosis and root resorption. In all cases of transplantation, patient selection minimal operating time, and good oral hygine will increase the chance for a successful prognosis.
Temperature-dependent Development Model of Larvae of mealworm beetle, Tenebrio molitor on Pollard
Seon-Gon Kim,Jung-Eun Kim,Do-Ik Kim,Hui-Yeon Koo,Duck-Soo Choi,Jong-Sun Kim 한국응용곤충학회 2012 한국응용곤충학회 학술대회논문집 Vol.2012 No.10
The developmental time of larvae of mealworm beetle, Tenebrio molitor was studied at six temperatures ranging from 17 to 30℃ with 60~70% RH, and a photoperiod of 14L:10D. Mortality of 1st~13th larva was very low at 17 and 20℃ but did not die over 22℃. Developmental time of larva decreased with increasing temperature. The total developmental time was longest at 17℃ (244.3 days) and shortest at 30℃ (110.8 days), suggesting that the higher temperature, the faster development period. The lower developmental threshold temperature and effective accumulative temperatures for the total larval stages were 6.0℃ and 2564.1 day-degrees. The relationship between developmental rate and temperature fitted a linear model and nonlinear model by Logan-6 (r2=0.95). The distribution of completion of each development stage was well described by the 3-parameter Weibull function (r2=0.89).
저사이클 피로 영역에서의 Alloy 617 모재와 용접재의 파괴시험편에 대한 거시적 및 미시적 관찰
김선진(Seon Jin Kim),랜도 디와(Rando Tungga Dewa),김영식(Yeong Sik Kim),김우곤(Woo Gon Kim),김응선(Eung Seon Kim) 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.2015 No.11
This paper presents the macro and microscopic fractography performed on fracture specimens from low cycle fatigue testings through Alloy 617 base metal and weldments. The weldment specimens were taken from GTAW pad of Alloy 617. The aims of the present study are to investigate the macro and microscopic aspects of low cycle fatigue fracture mode and mechanism of Alloy 617 base metal and the GTAWed weldment specimens. Fully axial total strain controlled tests had conducted at room temperature with total strain ranges of 0.6, 0.9, 1.2 and 1.5%. Macroscopic fracture surfaces of Alloy 617 base metal specimens showed a flat type normal to fatigue loading direction, whereas the GTAWed weldment specimens showed relatively shear/star type. The fracture surfaces of both the base metal and weldment specimens revealed the obvious fatigue striations at crack propagation regime. In addition, the fatigue crack initiation mechanism of the base metal showed a transgranular normal to fatigue loading direction, however, the GTAWed weldment specimens showed a transgranular about 45 degrees to fatigue loading direction.