저장 온도 및 상대습도가 비타민 정제 중 지용성 비타민 함량의 변화에 미치는 영향

김동섭,이재황,김세곤,이동언,박석준,이진희,이강표,최성원,백무열 경희대학교식량자원개발연구소 2007 硏究論文集 Vol.26 No.1

좌전하행지 관동맥 개구부위의 망사형의 관(Slotted Tube)스텐트와 나선형 코일(Coil)스텐트 삽입후 단기 및 장기 암상 경과의 비교

박훈기,박성욱,이일수,이상곤,김진우,이근,정상식,이철환,홍명기,김재중,박승정 대한순환기학회 1998 Korean Circulation Journal Vol.28 No.6

Thermal cycling 과 시효처리가 Glass-Ionomer수복재의 인장강도에 미치는 영향

이승익,백병주,김재곤,이승영,김문현 大韓小兒齒科學會 1999 大韓小兒齒科學會誌 Vol.26 No.4

본 연구에서는 구강환경과 유사한 액상의 조건하에서의 온도변화가 광중합형 글래스아이오노머계 수복재의 인장강도에 미치는 영향을 평가하기 위해 대조군으로 2종의 재래형 glass ionomer를 선택하고 실험군으로 2종의 광중합형의 resin-modified glass ionomer와 2종의 polyacid-modified resin composite을 선택한 다음 수중에서의 thermal cycling과 시효처리를 행하였으며, 다음과 같은 결론을 얻었다. 1. 글래스아이오노머 수복재의 인장강도를 측정한 결과, polyacid-modified resin composite, resin-modified glass ionomer 그리고 재래형 glass ionomer의 순으로 나타났다. 2. 인장강도는 30일간의 시효처리로 증가되는 경향을 보였다. 3. 재래형 glass ionomer 수복재의 인장강도는 thermal cycling 처리로 증가되는 경향을 보였으며, 37℃의 증류수 중에 1시간 침적한 군과 10,000회의 thermal cycling을 비교한 결과 유의한 차이로서 강도의 증가를 나타냈다(P<0.01). 4. thermal cycling 군의 인장강도는 DR군이 45.4MPa로 최대치를, FL군이 13.4MPa로 최소치를 나타냈으며, 각 군간의 통계적 유의성을 검증한 결과 polyacid-modified resin composite의 인장강도가 나머지 군과 유의한 차이를 보였다(p<0.05). 5. 특성강도는 DR군이 48.6MPa로 가장 높은 강도치를 보였으나, Weibull 계수는 CG군이 8.9로 가장 높은 값을 보여 시험재료 중에서 가장 작은 강도의 분산을 나타냈다. This study was performed to evaluate the effect of aging and thermal cycling on the tensile strength of six commercially available glass-ionomer materials: two chemically set glass-ionomer materials(Fuji Ⅱ, fuji Ⅸ), two resin-modified glass-ionomer materials(Fuji Ⅱ LC, Vitremer), and two polyacid-modified composite resins(Compoglass, Dyract). Rectangular tension test specimens were fabricated in a teflon mold giving 5mm in gauge length and 2mm in thickness. All samples were divided into 3 groups. Group 1 was immersed in a 37℃ distilled water for 1 hour. Group 2 was immersed in a 37℃ distilled water for 30 days. Group 3 was subjected to 10,000 thermal cycles between 5℃ and 55℃, and the immersion time in each bath was 15 seconds per cycle. Tensile testing was carried out at a cross-head speed of 0.5mm/min and fracture surfaces were examined with scanning electron microscope. The results obtained were summarized as follows; 1. The polyacid-modified composite resins were stronger than the resin-modified glass-ionomer materials, which were much stronger than the conventional glass-ionomer materials. 2. Tensile strengths were slightly increased after aging treatments for 30days. 3. Tensile strengths of conventional glass ionomers were significantly increased after thermal cycling treatment(p<0.01). 4. The highest tensile strength value of 45.4MPa was observed in the Dyract group and the lowest value of 13.3MPa was observed in the Fuji Ⅱ LC group after the thermal cycling test, and the strengths of polyacid-modified composite groups were significantly higher than those of other groups. 5. The highest characteristic strength value of 48.6MPa was obtained in the Dyract group, however the highest Weibull modulus value of 8.9MPa was obtained in the Compoglass group after thermal cycling test.

國際投資紛爭解決本部(ICSID)와 對蘇聯 및 東歐投資紛爭解決에 관한 小考

李載坤 忠南大學校 法學硏究所 1990 法學硏究 Vol.1 No.1

國際環境法과 非政府間機構(NGO)

李載坤 忠南大學校 法學硏究所 1996 法學硏究 Vol.7 No.1

11세 여아에서 발생된 성숙 낭성 기형종의 염종1예

이희민,김재현,이봉주,하태규,김흥곤,윤기중 圓光大學校 醫科學硏究所 1996 圓光醫科學 Vol.12 No.1

Mature cystic teratomas comprise 10% of all ovarian tumors and show the highest frequency of incidence in women under 20 years of age. Torsion of ovarian cyst is the most common complication in young female and lower abdominal pain, peritonitis, necrosis and shock are outcomes that require emergency treatment. Generally, gross finding of mature cystic teratoma shows that most of the entire ovary is replaced by multiple cystic masses, and rarely only small portion of the ovary is changed into cystic mass. We report a case of torsion of mature cystic teratoma in an 11 year old girl with a brief review of literature.

상아질과 복합레진 접착부의 피로파괴에 관한 실험적 연구

이지연,김재곤,차경,백병주 大韓小兒齒科學會 1995 大韓小兒齒科學會誌 Vol.22 No.2

The purpose of this study was to investigated and evaluate the tensile bond strengths and fatigue fracture characteristics of four dentin adhesive systems to dentin surface. 99 extracted human teeth were randomly assigned to four groups, and exposed dentin surfaces treated with four dentin bonding agents. Resin composite was bonded to dentin by use of commercial adhesive systems. Thensile bond strengths were determined in an Instron universal testing machine at a crosshead speed of 1mm/min. and the fatigue characteristics were measured by the fatigue characteristics were measured by the Fatigue testing machine(Electro-dynamic type). Fractured dentin surfaces were examined by SEM. The following results were obtained. 1. The tensile bond strengths were 21.45MPa in All-Bond 2 group, 18.67MPa in AElite group, and 18.59MPa in Scotchbond Multi-Purpose group were higher than 10.29MPa in Gluma group(P<0.001). 2. The fatigue life of All-Bond 2, AELite and Scotchbond Multi-Purpose group were singificantly higher than Gluma group when a 24.13MPa cyclic flexure load was applied(P<0.001). 3. The fatigue life of All-Bond 2, AElite and Scotchbond Multi-Purpose group were decreased when a 39.21 or 45.25MPa cyclic flexure load was applied, but these were not showed statistically different(P>0.05). 4. In All-Bond 2, AElite and Scotchbond Multi-Purpose group, the fatigue fracture of resin/dentin interface occured within a resin-infiltrated area, but in Gluma group, at near its interface with adhesive layer.

석회석을 이용한 칼사이트형 탄산칼슘의 제조 및 분산특성 연구

이재장,박종력,김병곤,장광택 강원대학교 부설 석재복합신소재 제품연구센터 2002 석재연 논문집 Vol.7 No.-

석회석은 국내 비금속 광물자원의 대부분을 차지하며 강원도와 충북 등의 일부지역에 편재되어 부존하고 있다. 그러나 CaO 함량이 54% 이상인 고품위 석회석은 전체 매장량의 5% 이하로 매우 빈약한 편이다. 더욱이 대분분의 생산량이 1차 산업용으로 사용되어 부가가치가 낮은 용도로 활용되고 있다. 본 연구에서는 이러한 석회석의 부가가치를 향상시키기 위하여 칼사이트형 침강성 탄산칼슘을 탄산화법을 이용하여 합성하고자 하였으며, 합성된 탄산칼슘 분체 및 현탁액의 분산안정성에 대하여 조사하였다. 분산이 양호하고 균일한 입도의 칼사이트 분체를 얻기 위해서는 CaO 농도 3%, CO_2 가스 유입량 300㎖/min, 교반속도 1,000 rpm에서 탄산화반응시 반응온도를 10~30℃로 유지하여야 함을 알 수 있었으며, 현탁액의 분산안정제로 PMAA와 PAA를 첨가제로 사용시 pH 6, 9, 12에서 0.2 wt% 첨가할 때 우수한 분산안정성을 나타내었다. A limestone reserves in korea is comparatively enough and reserved mainly in Kangwon-do and Chungchongbuk-do. However, it is known that limestone of high grade, more than 54% CaO, is about under 5% of total reserves. Besides, most of them are used for manufacture of cement as a primary material of low value. In this study, calcite type calcium carbonate powder or slurry was synthesized by carbonation process using limestone and dispersion properties of the prepared calcium carbonate suspension was investigated. In the carbonation reaction, the temperature of lime milk must be kept 10∼30℃, CaO consentration of 3%, stirring rate of 1,000 rpm and CO_2 gas flow rate 300㎖/min to manufacture stable dispersion calcite. Also, in the result of measuring the precipitation height of calcite suspension at pH 6, 9 and 12 as a function of the PMAA and PAA content, stable dispersion properties was observed at 0.2 wt% of PMAA and PAA. This may be due to the formation of the distinct adsorption layer between calcite particles by dispersant.

스톡홀름環境宣言,世界自然憲章 및 리우環境宣言의 國際環境法的 比較硏究

李載坤 忠南大學校 法學硏究所 1999 法學硏究 Vol.9 No.2

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.