골격형 III급 전치개교와 과개교합에 대한 비교고찰 및 MEAW에 의한 치험예

백승학(Seung-Hak Baek),양원식(Won-Sik Yang) 대한치과교정학회 1991 대한치과교정학회지 Vol.21 No.3

Presurgical Naso-Alveolar Molding Appliance for Unilateral Cleft Lip and Palate

Seung-Hak Baek(백승학),Won-Sik Yang(양원식),Sukwha Kim(김석화) 대한치과교정학회 1998 대한치과교정학회지 Vol.28 No.6

화학물질 취급사업장의 공정안전 통합보고서 작성에 관한 연구

김정덕(Jung Duck Kim),양원백(Won Baek Yang),임종국(Jong Guk Rhim) 한국위험물학회 2019 한국위험물학회지 Vol.7 No.1

Recently, fire, explosion and environmental pollution caused by leakage of chemical substances are gradually becoming larger, and the amount and risk of chemical substances to be handled are increasing. In 2017, the Ministry of Employment and Labor and the Ministry of Environment compiled and analyzed the results of the PSM, RMP, and ORA. However, the requirements of each system are different from those of the integrated report. Therefore, it is necessary to study the improvement methods of items - Chemical Information, Process Safety Information, Safety Facilities, etc. to meet the requirements of each system and to increase the utilization of the company.

소규모 폴리우레탄 반응공정의 압력방출장치 적정성 검토

김상령(Sang Ryung Kim),양원백(Won Baek Yang),임종국(Jong Guk Rhim) 한국위험물학회 2019 한국위험물학회지 Vol.7 No.1

Recently, in a polyurethane adhesive reactor in a small-scale polyurethane process, a runaway reaction occurs due to a reaction temperature control failure, so that a flammable reactant is ejected into a worker"s work area to form an explosive atmosphere, and a fire or explosion . The runaway reaction is a phenomenon in which high pressure is generated due to increase of vapor pressure, increase of product concentration and thermal expansion due to changes in flow rate, concentration, inflow amount and coolant temperature in the exothermic chemical reaction. In this study, the maximum calorific value of main materials used in polyurethane process, is analyzed by differential scanning calorimetry (DSC). Based on these study, the size of the safety release device was evaluated based on the heating value of polypropylene glycol, which is expected to cause runaway reaction under actual operating conditions. As a result of calculating the size of the protection device, rupture disc was 3 inch at DSC case and 2 inch at external fire case.

Analysis of alveolar molding effects in infants with bilateral cleft lip and palate when treated with pre-surgical naso-alveolar molding appliance

Dong-Seok Nahm(남동석),Won-Sik Yang(양원식),Seung-Hak Baek(백승학),Sukwha Kim(김석화) 대한치과교정학회 1999 대한치과교정학회지 Vol.29 No.6

반도체용 특수가스 공급장치 내부에서의 가스누출 원인에 따른 유동해석에 관한 연구

김정덕(Jung-Duck Kim),권기선(Ki-sun Kwon),임종국(Jong-Guk Rhim),양원백(Won-Baek Yang) 한국가스학회 2021 한국가스학회지 Vol.25 No.2

반도체 제조에 사용하는 특수가스를 공급하는 설비는 인화성·독성·부식성을 지닌 유해·위험물질을 주로 취급하는데, 이러한 공급설비로는 주로 가스캐비닛이 사용되고 있다. 가스캐비닛 내 파열판을 통한 누출, 누출 개구부의 확대가 가능한 누출, 누출 개구부가 확대되지 않는 누출의 케이스별로 공급장치 내부 상태 및 외부로의 확산 영향을 누출 원인별로 분석하였다. 이 경우 누출 단면적에 따라 공급장치 외부로 가스가 누출되는 경우가 발생함을 확인하였다. 외부로 누출되는 가스의 농도에 따라 폭발분위기 형성 등 위험성이 존재하는 요인으로 작용하며, 위험에 따라 공급설비의 안전운전절차 등 제반 조치사항을 다시 검토할 필요가 있음을 확인하였다. Facilities that supply specialty gases used in semiconductor manufacturing mainly handles with hazardous and dangerous substances with flammable, toxic, and corrosive properties, and gas cabinets are mainly used as such supply facilities. The effects of the supply facilities were analyzed for each leak through the rupture disk in the gas cabinet and a leak where the leak hole. In this case, gas leaked to the outside depending on the leak area. It is a factor that creates a risk depending on the concentration of the leaked gas. Depending on the risk of leakage, all measures such as safe operation procedures should be reviewed again.

반도체 배기 공정에서 복합 처리 방식으로 인한 폭발 사고 예방대책에 관한 연구

최세욱(Se Wook Choi),이대준(Dae Joon Lee),김상령(Sang Ryung Kim),김상길(Sang Gil Kim),정정희(Jeong Hee Jeong),양원백(Won Baek Yang) 한국가스학회 2022 한국가스학회지 Vol.26 No.5

반도체 공장은 인구가 밀집된 지역에 위치하여 제조 공정에서 취급되는 위험물질의 안전한 처리가 무엇보다 중요하다. 특히나 반도체 제조 공정에서 취급 후 배출되는 위험물의 종류는 매우 다양하며 물질별로 연소, 흡수, 흡착방식 등 처리 방법도 매우 복잡하다. 따라서 최근 반도체 배기 처리 공정에서는 하나의 처리 설비에 두 개 이상의 처리 방식을 적용하고 있는데, 이러한 복합 처리방식 적용으로 예상치 못한 사고가 발생하고 있다. 본 연구에서는 최근의 사고 사례인 Scrubber 방식과 전기 집진방식을 함께 적용한 처리 설비의 사고 원인을 파악하고 예방대책을 제시하여 복합 처리방식 적용 시 유의해야 할 점을 알아보고자 한다. Since semiconductor factories are located in densely populated areas, safe handling of hazardous materials handled in the manufacturing process is of utmost importance. In particular, the types of hazardous substances discharged after handling in the semiconductor manufacturing process are very diverse, and the treatment methods such as combustion, absorption and adsorption methods for each material are very complicated. Therefore, in recent semiconductor exhaust treatment processes, two or more treatment methods are applied to one treatment facility, and unexpected accidents occur due to the application of such a complex treatment method. In this study, the cause of accidents in treatment facilities that applied both the scrubber method and the electrostatic precipitation method, which are recent accident cases, are identified, and preventive measures are suggested to find out the points to be noted when applying the complex treatment method.

토끼 태자에 형성시킨 구순열상의 치유과정에서 세포외기질 분포에 관한 연구

양원식,백승학 대한치과교정학회 1998 대한치과교정학회지 Vol.28 No.1

태아와 성체의 상처치유과정에서 다른 점으로는 태아 상처가 염증반응과 반흔조직의 생성이 없이 신속히 치유됨을 들수 있다. 태자상처의 비반흔성 치유와 세포외기질의 역할을 연관지어 해석하려는 노력이 진행중에 있으나, 각 실험 동물종간의 차이 및 세포외기질 구성요소의 다양성 등 많은 변수가 아직 미결의 과제로 남아 있다. 본 연구의 목적은 토끼 태자의 상처 치유과정에서 반흔조직의 형성과 관련이 있는 세포외 기질의 주요성분인 교원질 Ⅰ,Ⅲ,Ⅳ,Ⅴ형, fibronectin, laminin의 시기적 출현 및 분포양상을 조사하기 위한 것이다. 뉴질랜드산 흰 토끼를 임신 3기의 중반인 24일 째에 자궁절개술을 시행하고 태자에 인위적으로 구순열상을 만든 후, 봉합한 군(봉합군)과 봉합하지 않은 군(비봉합군), 정상대조군(sham operation group)으로 나누고 이들을 각각 수술 후 1,2,3,5,7일째에 희생시켜 상처치유에 대한 육안관찰 소견과 H&F염색소견 및 교원질Ⅰ,Ⅲ,Ⅳ,Ⅴ형, fibronectin, laminin의 면역조직화학적 염색 소견을 관찰하여 다음과 같은 결론을 얻었다. 1. 봉합군과 비봉합군에서 전기간동안 염증반응은 없었다. 2. 비봉합군의 재상피화가 봉합군에 비해 다소 느렸다. 3. 교원질 Ⅰ,Ⅲ,Ⅴ형은 봉합군과 비봉합군에서 2일군까지는 발견되지 않았고 3일군 이후 존재하였으나 염색정도가 인접정상조직이나 정상대조군에 비하여 증가하지 않았다. 4. 상피 기저막에서 교원질 Ⅳ형의 염색소견은 봉합군과 비봉합군에서 3일군이 다소 증가하였으나 그후 감소하여 인접정상조직이나 정상조직이나 정상대조군과 차이가 없었고, laminin의 염색소견은 봉합군과 비봉합군에서 5일군이후 발견되었고 염색정도의 증감없이 7일군까지 유지되었고 인접정상조직이나 정상대조군과 차이가 없었다. 5. 혈관내피세포 기저막에서 laminin과 교원질 Ⅳ형의 염색소견은 인접정상조직이나 정상대조군에 비해서 증가하지 않았다. 6. Fibronectin은 봉합군과 비봉합군에서 fibrin clot과 창상 기저부 및 창상연을 따라 3일군까지 염색소견이 증가하였다가 그후 감소하여 인접정상조직이나 정상대조군과 차이가 없었다. Adult wound healing is accompanied with inflammation and eventual scar formation, whereas fetal wounds heal rapidly by mesenchymal prpliferation without significant inflammatory cell participation and with minimal or no scar formation. The cellular mechanisms underlying these differing forms of wound healing are unknown but the extracellular matrix, through its effects on cell function, may play a key role. Therefore the purpose of this study is to investigate the spatial and temporal deposition of several component of extracellular matrix, which are known to be involved with scar formation, in the artificially created cleft lip wound healing of fetuses. The author had undergone hysterotomy and created cleft lip-like defects on fetuses of New Zealand White Rabbit in mid-third trimester(24 days). Fetuses were divided into the repaired group, the unrepaired group and the sham-operated control group. At 1,2,3,5,7 days after procedure, fetuses were obtained by Caeserean section. After documenting the viability of fetuses, they were photographed to compare size and facial morphology and sectioned for histological examination by H&E stain and spatial and temporal deposition of collagen typeⅠ,Ⅲ,Ⅳ,Ⅴand fibronectin, laminin by immunohistochemical method. The findings are summarized as follows 1. There were lack of inflammation in the repaired and the unrepaired group during experimental periods. 2. The reepithelialization of the unrepaired group was slower than that of the repaired group. 3. Collagen Ⅰ,Ⅲ,Ⅴ were found from post-op. third day. There were no difference of distribution in the control, the repaired and the unrepaired group. Collagen typesⅠ,Ⅲ,Ⅴ were present in all groups with restoration of the normal collagen pattern in the fetus. This implies that lack of scarring in fetal wounds is due to the difference of collagen organization pattern within wound and not simply lack of collagen formation. 4. Collagen Ⅳ was slightly increased at post-op. third day and decreased after post-op. fifth day. Eventually there were no difference in control, the repaired and the unrepaired group. Laminin was found at post-op. fifth day and maintained staining density until post-op. seventh day. There were no differences in the control, the repaired and the unrepaired group. According to staining of laminin and collagen typeⅣ in epithelial basement membrane, formation of epithelial basement membrane was not completed until reepithelialization was finished. 5. According to staining of laminin and collagen typeⅣ, there were no increase of neovascularity in the repaired and the unrepaired group. 6. Fibronectin was increased until post-op. third day at fibrin clot, wound base and margin and decreased after post-op. fifth day. Eventually, there were no differences in the control, the repaired and the unrepaired group. So it implies fibronectin plays a role as provisional matrix for fetal wound healing.

한국인 성인의 악안면 연조직의 심미적 안모형태분석에 관한 연구

백승학,양원식 대한치과교정학회 1991 대한치과교정학회지 Vol.21 No.1

This study was designed to analyze morphological characteristics of Korean young adults, norms and standard deviation of variables, sexual differences, correlationship between each area of face and correlationship between hard tissue and soft tissue. The primary sample consisted of 45 males and 57 females who were early and middle twenties and had acceptable profile, no history of previous orthodontic treatment, absence of remarkably large overjet and overbite, full complement of permanent teeth, Class Ⅰ skeletal and dental relationships and good vertical facial proportions. Their cephalograms were analyzed morphologically with a computer morphometrics. Then the final sample- 25 males and 38 females -were selected within 1 S.D. of E-line, ANB, P/A facial height ratio, Interincisal angle, L1 to A-Pog, ODI and APDI. The results of the study were as follows: 1.In the form and proportion of facial skeleton there were no significant differences between males and females, but in the size males were larger than females. 2.The dental protrusion patterns had no significant sexual difference and no significant correlationship between protrusion of upper lip and inclination of upper incisor. But mentolabial angle had positively correlated with interincisal angle and negatively with inclination of upper and lower incisor. 3.In the relationship between nose and soft-tissue profile, males were larger than females in nasal length, height and angular measurements. 4.In analysis of soft-tissue profile, males were larger than females in the length and thickness. In the angular measurements and proportion of soft-tissue profile, there were no significant differences between males and females.

Presurgical Naso-Alveolar Molding Appliance for Unilateral Cleft Lip and Palate

Baek, Seung-Hak,Yang, Won-Sik,Kim, Sukwha 대한치과교정학회 1998 대한치과교정학회지 Vol.28 No.6

본 연구의 목적은 1)편측성 순구개열 신생아 환자에 대한 술전 비치조 정형장치(PNAM)치료를 소개하고 2) 이 장치의 치조골 정형 효과를 평가하는 것이다. 서울대학교 병원 교정과에 내원하여 PNAM장치를 사용하여 치료받은 4명의 편측성 순구개열 호나자(남자 3명, 여자 1명, 평균 초진연령: 23.2일)을 대상으로 하였으며, 치조골에서 대분절과 소분절 파열부간의 평균거리는 8.27mm였고 치조골 정형치료의 평균기간은 9.7주였다. 초진시(Ti)와 성공적인 치조골 정형술이 이루어진 시기(T2)에 이들 환자의 인상을 채득하여 모형을 제작한 후, 사진촬영과 digital caliper를 사용하여 7개의 길이 항목과 5개의 각도항목을 계측하였다. SPSS win. ver 7.5프로그램을 사용하여 통계처리 하였고, 평균치의 차이를 비교하기 위하여 paired t-test를 사용하였다. 1. 신생아 치조골 후방부는 치조골 정형술을 시행하는 동안 안정된 구조물이었다. 2. 치조골 정형술에 의하여 대분절의 전방 성장이 억제되었다. 3. 치조골 정형술에 의한 파열부의 패쇄는 주로 대분절 전방부의 내측과 후방 굴곡 및 소분절 전체의 외측 굴곡에 의한 것이었다. The goals of this study were to present presurgical naso-alveolar molding(PNAM) appliance in unilaterla cleft lip and palate treatment and to evaluate the effects of PNAM appliance on alveolar molding. Samples were consisted of 4 unilateral cleft lip and palate infants(3 males and 1 female, mean age=23.2 days after birth) who were treated with PNAM appliances in Department of Orthodontics, Seoul National University Dental Hospital. Average alveolar cleft gap between the greater and lesser segment was 8.27 mm and average duration of alveolar molding treatment was 9.7 weeks. These patients' models were obtained at initial visit(T1) and after successful alveolar molding(T2). Seven linear and five angular variables were measured by using photometry and digital caliper. All statistical analyses were performed by SPSS win ver. 7.5 program. Paired t-test was used to compare the mean values. 1. The posterior part of alveolar segments are the stable structures during alveolar molding treatment period in infants. 2. Forward growth of th greater segment may be hindered by the action of alveolar molding. 3. The closure of cleft gap during alveolar molding were usually due to inward and backward bending of the anterior part of the greater segment and outward bending of the whole lesser segment.