전기도금을 이용한 스테인레스 스틸 각형 선재의 굵기 증가 후 물성 변화

이정석,이기헌,황현식 대한치과교정학회 2003 대한치과교정학회지 Vol.33 No.2

본 연구는 전기도금을 이용하여 각형 선재의 굵기를 증가시킨 후 기존의 선재와 물성을 비교함으로서 이의 임상적 적용 가능성을 알아보고자 시행되었다. 한 변의 길이가 0.016 인치인 정사각형 스테인레스 스틸 교정용 선재에 니켈 전기도금을 시행하여 굵기를 0.01 인치 증가시켜 한 변의 길이가 0.017 인치인 정사각형 선재로 만들었고 도금층의 밀착성을 증진시키기 위해 400℃의 전기로 에서 10분간 열처리를 시행하였다. 시편의 물성변화를 알아보기 위하여 전기도금을 이용하여 제작된 15개의 시편을 실험군(016P군)으로, 기존의 0.016인치(016), 0.017 인치(017군) 스테인레스 스틸 교정용 선재를 대조군으로 설정한 후 3점 굴곡 시험과 비틀림 시험을 시행하여 다음과 같은 결과를 얻었다. 1. 3점 굴곡 시험 결과 016P군에 비해 강성과 항복강도, 국한강도 모두 증가하는 경향을 보였으며, 강성과 극한강도는 통계적으로 유의한 차이가 있었다(p<0.05). 2. 3점 굴곡 시험 결과016P군이 017보다 강성과 항복강도, 극한강도 모두 낮은 경향을 보였으며, 강성은 통계적으로 유의한 차이가 있었다(p<0.05). 3. 비틀림 시험 결과 016P군이 016군에 비해 비틀림 모멘트, 최대 비틀림 모멘트 모두 높았으며, 통계적으로 유의한 차이가 있었다(p<0.05). 4. 비틀림 시험 결과 016P군이 017군에 비해 비틀림 강성과 항복 비틀림 모멘트, 최대 비틀림 모멘트 모두 낮은 경향을 보였으며, 이 중 항복 비틀림 모멘트와 최대 비틀림 모멘트에서 통계적으로 유의한 차이가 있었다(p<0.05). 이상의 결과를 요약해 보면 각형 선재에 도금을 시행하여 굵기를 증가시키고 물성이 증가될 수 있음을 알았다. 비록 도금을 시행한 016P군이 기존의 017군보다 강성이 낮았으나 이는 반대로 016P군이 017군보다 탄성이 높음을 나타내며 토크조절이 부족한 경우 브라켓 슬롯에 쉽게 삽입되어 교정력을 발휘할 것으로 기대된다. The purpose of this study was to evaluate clinical applications of electroplating method through investigation of the physical properties of orthodontic rectangular wires according to varying their cross section. For the study, it was accomplished to electroplate the 0.016-inched orthodontic rectangular stainless steel wire. The cross section of stainless steel orthodontic rectangular wire increased from 0.016 x 0.016 inch to 0.017 x 0.017 inch by electroplating. The wire was heat treated to improve an adhesion between the wire and electroplated metal. A three=point bending test and torsion test were conducted in order to compare physical properties among three wire groups; 0.016 X 0.016 wires (group 016), electroplated 0.016 x 0.016 wires (group 016P) and 0.017 x 0.017 wires (group 017). Through the investigation of each wire group, following results were obtained. 1. At three-point bending test, the group 016P showed higher tendency in the degree of stiffness, yield strength and ultimate tensile strength than the group 016. Stiffness and ultimate tensile strength showed statistically significant differences between two groups at three-point bending test (p<0.05). 2. Stiffness, yield strength, and ultimate tensile strength of the group 016P showed lower tendency than those of the group 017. Stiffness showed statistically significant differenced between two groups at three-point bending test (p<0.05). 3. Torque/twist rate, yield torsional moment, and ultimate torsional moment of the group 016P showed higher tendency than those of the group 016. All measurements showed statistically significant differences between two groups after torsion test (p<0.05). 4. Torque/twist rate, yield torsional moment, and ultimate torsional moment of the group 016P showed lower tendency than those of the group 017. Yield torsional moment, and ultimate torsional moment showed statistically significant differences between two groups after torsion test(p<0.05)

綠豆品種集團에 있어서 量的形質에 대한 遺傳分析

李相昊,高美錫,金碩鉉 慶尙大學校 1985 論文集 Vol.24 No.2

多收性 綠豆品種 育成을 위한 基礎資料를 얻기 위하여 21個 品種을 材料로 各 形質에 대한 遺傳力 및 遺傳相關等을 推定한 바, 그 結果는 다음과 같다. 1. 遺傳力은 100 粒重 및 傳長, 그리고 開花日數는 높았으나 成熟日數와 粒重은 낮았고 其他 形質들은 中間程度였다. 2. 形質相互間의 相關關係에서 開花日數와 莖長은 莖長과 100 粒重을 제외한 全 形質間과 正외 相關이 있었고, 100 粒重은 成熟日數와 萊長과는 표의 相關으로 其他 全 形質과는 負의 相關을 보였다. 3. 收量, 즉 粒重은 開花日數, 莖長, 莖直徑, 分枝數 및 樣當萊數等과 高度의 正의 相關을 보여 이 形質 들이 綠豆의 收量을 增大시킬 것으로 推定되었다. This experiment was conducted to estimate genetic parameters, such as heritabilities, genotypic and phenotypic correlation coefficients of some agronomic characters in mungbean. Twenty one varieties were planted in a randomized block design with three replications and 10 quantitative characters, i. e., days to flowering, days from flowering to maturity, days to maturity, plant height, stem diameter, branch numbers per plant, pod length, pod numbers per plant, 100 grain weight and grain weight per plot were observed. The results obtained are summarized as follows: 1. The highest heritability value was found for 100 grain weight, and those of days lo flowering and pod length were higher than other characters. But the lower values were found with days from flowering t9 maturity and grain weight per plot. 2. The genotypic correlations among all pairs were slightly higher than the corresponding phenotypic correlations. 3. The phenotypic and genotypic correlations between grain weight and other characters indicated that high grain yield was genetically correlated with days to flowering, plant height, stem diameter, branch numbers per plant and pod numbers per plant. Therefore, these characters were suggested that selection for high yield may be more effective than the other agronomic characters.

전기도금을 이용한 스테인레스스틸 각형 선재의 굵기 증가 후 물성 변화

이정석,황현식,최광철,문재동 전남대학교 치의학연구소 2002 구강과학 Vol.14 No.1

The purpose of this study was to evaluate clinical applications of electroplating method through investigation of the physical properties of orthodontic rectangular wires according to varying their cross section. For the study, it was accomplished to electroplate the 0.016-inched orthodontic rectangular stainless steel wire. The cross section of stainless steel orthodontic rectangular wire increased from 0.016 X 0.016 inch to 0.017 X 0.017 inch by electroplating. The wire was heat treated to improve an adhesion between the wire and electroplated metal. A three-point bending test and torsion test were conduced in order to compare physical properties among three wire groups; 0.016 X 0.016 wires(group 016P) and 0.017 X 0.017 wires(group 017). Through the investigations of each wire group, following results were obtained. 1. At three-point bending test, the group 016P showed higher tendency in the degree of stiffness, yield strength and ultimate tensile strength than the group 016. Stiffness and ultimate tensile strength showed statistically significant differences between two groups at three-point bending test(p<0.05). 2. Stiffness, yield strength, and ultimate tensile strength of the group 016P showed lower tendency than those of the group 017. Stiffness showed statistically significant differences between two groups at three-point bending test(p<0.05). 3. Torque/twist rate, yield torsional moment, and ultimate torsional moment of the group 016P showed higher tendency than those of the group 016. All measurements showed statistically significant differences between two groups after torsion test(p<0.05). 4. Torque/twist rate, yield torsional moment, and ultimate torsional moment of the group 016P showed lower tendency than those of the group 017. Yield torsional moment, and ultimate torsional moment showed statistically significant differences between two groups after torsion test(p<0.05). Xylitol is a 5-carbons carbohydrate, which can be replaced with sucrose for preventing caries. The replication of Streptococcus mutans and its formation of artificial plaque were studied in the media containing xylitol. The combined effect of xylitol and other carbohydrates on Streptococcus mutans was also studied. The replication of Streptococcus mutans was inhibited according to the increased concentration of xylitol. Streptococcus mutans replicated at the initial stage of incubation in the media contaning glucose, fructose or lactose, while replication from the beginning of incubation in the media containing fructose as combining with xylitol. The formation of artificial plaque by Streptococcus mutans was significantly reduced in the media containing with xylitol and fructose. These results indicated that the replication of Streptococcus mutans was inhibited according to the increased concentration of xylitol, and the formation of artificial plaque by Streptococcus mutans was significantly inhibited in the media containing xylitol and fructose.

올레산의 비율에 따른 아데노신의 경피 투과의 영향

남현빈,정세진,구민석,오예진,김용민,이훈희,윤수정,임정균 순천향대학교 부설 산업기술연구소 2021 순천향 산업기술연구소논문집 Vol.27 No.2

In addition to the development of functional cosmetics, technology to increase percutaneous absorption rate when applied to the skin is an important task. In this experiment, oleic acid was used as a skin absorption promoter, and its effect on transdermal permeability of adenosine was studied and analyzed using a skin-like membrane. As a result of the experiment, it was investigated that the permeability coefficient and concentration of adenosine are proportional to the content of oleic acid. This indicates that a high proportion of oleic acid is effective as a skin absorption promoter.

열린 교육과 미술 교육 : 그 상관성에 관하여

이쌍재,이현석 晋州敎育大學校 初等敎育硏究所 1997 初等敎育硏究 Vol.7 No.-

청소년의 유도수련 참여가 사회관계성향에 미치는 영향

한이석,진종현,정찬수 龍仁大學校 體育科學硏究所 2001 體育科學硏究論叢 Vol.11 No.1

This research was designed to describe the effect of teenager's participation in Judo training to the social relationship. We examined the effect of teenagers participating in Judo training and non-participated teenagers to the subordinate factor of the social relationship inclination ; sympathy, receptiveness, sociality and friendship. The subjects for this research were total 394 students participating in Judo class and non-participated students among middle school based on Daejeon city by the Stratified Cluster Random Sampling method. To investigate this research, we modified and supplemented the standardized questionnaire of human nature test and personal relations inclination test for teenagers. The reliance coefficient was shown as the value of a'=.5726∼.6816 We applied for SPSS v10.0 for Windows to progress the data of study. The result of executing Analysis of Covariance, ANCOVA to investigate the effect of teenager's participation in Judo training to the social relationship inclination is as follows; a. The participation in Judo training for the class affects the sympathy as the subordinate factor of the social relationship inclination. b. The participation in Judo training for the class affects the receptiveness as the subordinate factor of the social relationship inclination. c. The participation in Judo training for the class affects the sociality as the subordinate factor of the social relationship inclination. d. The participation in Judo training for the class affects the friendship as the subordinate factor of the social relationship inclination.

크롬(Ⅵ)의 체내 흡수와 소실속도에 관한 연구

김현영,이성배,임철홍,이권섭,정용현,이종성,한정희,전윤석,황호순,이용묵 한국산업위생학회 2003 한국산업보건학회지 Vol.13 No.1

The CrO3 mostly used in plating. metal surface disposal, leather, cosmetic manufacturing, as an experiment material by repeatedly inhaling and exposure the male S.D. rats at a 0.00, 0.2., 0.50, 1.25 mg/㎡ concentration(particle size: 0.5-0.5 aerosol)6hours a day, 5day a week in 13weeks comparing with 2weeks, 8weeks of recovery group about the noxiousness of the experiment animal and the reduce scale of the CrO3 in the internal organ especially in blook and respiratory organ with the period of convalescent and clearance. The experiment results which we received are as follows. 1. In blood the RBC, HGB and HCT experiment, rats with 0.20, 0.50 mg/㎡ concentration showed that there were some decreases but not dependent. The kidneys absolute weight compared with control group was reduced intentionally(p〈0.05) and the lungs absolute weight compared with control group showed intentional increase(p〉0.05). 2. After the exposure of the experiment material, the whole blook, l\blood plasma and red blood cell in blood by (x): the period of convalescent, per (y); the decreasing of Cr concentration, was y=66.51 e -0.057x, y=67.2 e-0.101x, y=70.01 e-0.030 in 0.50 mg/㎡ exposure concentration by calculating the clearance coefficient of correlation, and the half life (day)was estimated 12.0, 6086, 23.0 each. 3, After the exposure of the experiment material, the experiment animals lung, liver and kidneys by(x); the period of convalescent, per (y); the decreasing of Cr conentration, was y=1808 e-0.00493x, y=12.02e-0.0297x, y=67.61 e-0.0292x in 0.50mg/㎡ exposure concentration by calculating the clearance coefficient of correlation, and the half life(day)was estimated 140.6, 23.3, 23.7, each, and including lung, liver with all of the experiment internal organs, the Cr clearance decreased as the exposure concentration increased.

SD Rats를 이용 1-hexene의 흡입독성 연구

김현영,임철홍,정용현,이권섭,이성배,이준연,한정희,전윤석,이용묵 한국환경독성학회 2001 환경독성보건학회지 Vol.16 No.4

The purpose of this study was to investigate the acute (4 hours) and repeated-dose (6 hours a day, 5 days a week, 4 weeks) toxic effects of I -hexene on Sprague- Dawley (SD) rats which were treated by inhalation. The results were as follows; I. The median lethal concentration (LC_(50)) was estimated 52,694 ppm (confidence limit 95%; 49,494~55,447 ppm) in acute inhalation. Abnormal clinical signs related to the l-Hexene were not observed with the acute inhalation dose. Gross findings of necropsy revealed on evidence of specific toxicity related to the 1-hexene, II. By repeated inhalation exposure the body weight of male were more or less reduced by the dose of 2,500 ppm and 5,000 ppm compared with control group. However there were no significant variation hematology and blood biochemistry for the exposed rats compared with the control rats. Abnormal clinical signs and gross findings of necropsy related to the 1-hexene were not shown. In conclusion when we exposed I-hexene to SD rats for 4 weeks, 5 days per week, 6 hours per day, the Lowest observed effect level (LOEL) was over 2,500 ppm and Non observed effect level (NOEL) was below 500 ppm.

상행성 운동마비와 보행 실조로 발현한 비전신성 혈관염성 신경병증 1예

김현석,김성민,권기한,이병철,신준현,강인수 대한노인병학회 1999 Annals of geriatric medicine and research Vol.3 No.4

수술중 기계적 환기시 HME (Heat and Moisture Exchanger)가 기도저항에 미치는 영향

윤석화,김일문,이상묵,유재현 충남대학교 의과대학 지역사회의학연구소 1996 충남의대잡지 Vol.23 No.2

To compare the airway resistance effects of two heat and moisture exchangers(HME) during short-term intraoperative volume controlled mechanical ventilation. Following a randomized order, the patients were ventilated during 3hrs with two HMEs(Pall conserve and Humi-vent filter). In each patient and for each 5 min, lhr, 2hrs and 3 hrs period, body temperature and airway resistance were measured. The hydrophobic HME (Pall conserve) had a good theraml conservation capacity, but increase airway resistance(11.7±2.9cm H_2O/1/s to 15 4±3.4 after lhr, to 17.3±2.5 after 2hrs, to 17.5±3.3cm H_2O/l/s after 3hrs). The hygroscopic filter(Humi-vent filter) had a good thermal conservation capacity, and less increase airway restance than Pall conserve(13.0±2.3 to 15. 4±3.4. after 1hr, 15.9±2.5 after 2hrs, 15.0±3.3 cmH2O/I/s after 3hrs). The hygroscopic HME had a thermal and humidification capacity and less increase the airway resistance.