도라지의 일반성분

정진환,신평균,류진창,장대식,조성환 ( Jin Hwan Chung Pyung Gyun Shin,Jin Chang Ryu,Dae Sik Jang,Sung Hwan Cho ) 한국응용생명화학회 1997 Applied Biological Chemistry (Appl Biol Chem) Vol.40 No.2

Platycodon root contains abundant pharmaceutical substances and is widely used as a food and a medicinal herb. To identify the major components of the three-year-old and the 24-year-old platycodon roots cultivated in a local farm were analyzed and compared with their chemical compositions prior to their pharmaceutical substances, which were used as the fundamental data. There were no differences in chemical composition, inorganic compositions and fatty acid compositions between the 24-year-old and three-year-old roots. Total amino acid contents were 375.8 ㎎% and 891.6 ㎎% in the 24-year-old and three-year-old platycodcon roots, respectively. Sixteen species of amino acid were identified by amino acid autolyzer except cysteine both in the 24-year-old and three-year-old roots. Linoleic acid, which was the highest fatty acid contained both in the 24-year-old and three-year-old roots, was estimated to be 48.7% and 39.1% of total fatty acids, respectively.

도라지의 약리성분

정진환,신평균,류진창,장대식,조성환 ( Jin Hwan Chung,Pyung Gyun Shin,Jin Chang Ryu,Dae Sik Jang,Sung Hwan Cho ) 한국응용생명화학회 1997 Applied Biological Chemistry (Appl Biol Chem) Vol.40 No.2

Platycodon root contains abundant pharmaceutical substances and is widely used as a food and a medicinal herb. The three-year-old and the 24-year-old Platycodon roots cultivated in a local farm were analyzed and compared with their pharmaceutical substances to identify the major components. Reverse column HPLC analysis of ethanol extracts from the 24-year-old roots showed some distintive peaks after the retention time of 50 min which were absent in the extracts from the three-year-old roots. This indicates that several pharmaceutical substances are present in the older roots. There were no differences in sterol composition and saponin content between the 24-year and three-year-old roots. The 15-year-old and the 23-year-old Platycodon roots, the 6-year-old Ginseng root, and the three-year-old Condonopsis root all did not show significant anticomplement activity.

변위법(變位法)에 의한 곡선형교(曲線桁橋)의 정적탄성해석(靜的彈性解析)

정진환,장승필,Chung, Jin Hwan,Chang, Sung Pil 대한토목학회 1986 대한토목학회논문집 Vol.6 No.2

The stiffness matrix of circularly curved frame elements including the warping effects is formulated by the solutions of vlasov's differential equations, and the procedure for the elastic static analysis of curved girder systems by the displacement method is presented. The validity of this method has been demonstrated by comparing the analysis results with other solutions. And if the tangential lines of the two frame element axes connected at any nodal point coincide, the transformation to the global coordinate system can be omitted when we analyze the structures consisting of circularly curved elements. The theory introduced in this thesis can be applied with sufficient accuracy to the structures built up with horizontally circular curved frame elements which have closed or open cross sections and are symmetric to the axis perpendicular to the plane of the curvature, such as prestressed concrete box girder bridges. ?(warping)의 효과(?果)가 포함된 원형곡선부재(圓形曲線部材)의 부재강도(部材剛度)매트릭스를 미분방정식(微分方程式)의 해석적(解析的)인 해(解)를 사용(使用)하여 유도(誘導)하고, 원형곡선부재(圓形曲線部材)의 변위법(變位法)에 의(依)한 정적탄성해석방법(靜的彈性解析方法)을 제시(提示)하였다. 예제(例題)를 통하여 얻어진 결과(結果)는 다른 방법(方法)에 의(依)한 해석결과(解析結果)와 잘 일치(一致)하고 있어, 본(本) 논문(論文)의 정당성을 입증하였고 원형곡선부재(圓形曲線部材)로 구성(構成)된 구조물(構造物)을 해석(解析)할 때 곡선좌표계(曲線座標系)를 사용(使用)하므로써, 한 절점에 연결된 양쪽 부재축(部材軸)의 접선(接線)이 일치(一致)한다면, 국부좌표계(局部座標系)로부터 전체좌표계(全體座標系)로의 변환(變換)이 필요(必要)없음을 보였다. 본(本) 논문(論文)에서 유도(誘導)된 이론(理論)은 P.S. 상자형(箱子桁)의 폐단면(閉斷面) 또는 부재평면(部材平面)과 수직(垂直)인 축(軸)에 대하여 대칭인 개단면(開斷面)을 갖는 수평원형곡선부재(水平圓形曲線部材)로 이루어진 구조물(構造物)의 엄밀(嚴密)한 해석(解析)에 적용(適用)할 수 있다.

연구논문 - Microstructure and Mechanical Property Relations - : 잔류오스테나이트를 함유한 고강도 냉연강판의 가공경화와 변태거동

정진환,장영원 ( Jin Hwan Chung,Young Won Chang ) 대한금속재료학회 ( 구 대한금속학회 ) 1991 재료강도 심포지엄 Vol.- No.-

저온동작용 $Co_{3}O_{4}$ 부탄가스 감지 소자(I)

정진환,최순돈,Chung, Jin-Hwan,Choi, Soon-Don 한국센서학회 1996 센서학회지 Vol.5 No.6

저온에서 동작 가능한 센서를 개발하기 위하여 $Co_{3}O_{4}$ 후막 소자를 제조하였다. $Co_{3}O_{4}$ 분말은 질산코발트 수용액으로부터 침전하여 얻었으며 binder인 ethylene glycol과 혼합하여 알루미나 기판상에 후막을 인쇄하였다. 제조된 후막에 대해 binder 함량 및 열처리 조건에 따른 부탄가스의 감도 및 회복성을 조사하였다. 동작 온도 $250^{\circ}C$에서 15% ethylene glycol을 함유한 $Co_{3}O_{4}$ 분말을 $300^{\circ}C$ 에서 24시간 동안 열처리한 소자가 부탄가스에 대하여 최고의 감도를 나타내었다. 감도는 500ppm 부탄가스에 대하여 1.1 정도로, 동작 온도 $350{\sim}400^{\circ}C$에서 상용 $SnO_{2}$ 가스 감지 소자의 감도 $0.8{\sim}0.85$와 비교할 때 매우 높았다. 응답 특성은 매우 좋았으나 회복성은 나쁜 것으로 나타났다. In order to develop gas sensor operating at low temperature, thick film $Co_{3}O_{4}$ sensor was fabricated. $Co_{3}O_{4}$ powder was prepared by precipitation from cobalt nitrate solution and the powders containing ethylene glycol as a binder was screen-printed on alumina substrate. Characteristics of sensitivity, response time, and recovery were investigated in terms of binder content and heat treating conditions. The $Co_{3}O_{4}$ sensor contained 15% ethylene glycol and heat-treated at $300^{\circ}C$ for 24hr showed the highest sensitivity at the operating temperature of $250^{\circ}C$. Its sensitivity of 1.1 to 5000ppm butane gas was very high, as compared with $0.8{\sim}0.85$ at the operating temperature of $350{\sim}400^{\circ}C$ for a commercial $SnO_{2}$ gas sensor. It is found that response time was fast, but recovery was poor for the sensor.

도라지의 휘발성분에 관한 연구

정진환(Jin Hwan Chung),선우선(Sun SunWoo),권재상(Jae Sang Kwon),신평균(Pyung Gyun Shin),조성환(Sung Hwan Cho) 한국응용생명화학회 1996 Applied Biological Chemistry (Appl Biol Chem) Vol.39 No.6

To identify the volatiles of Platycodon roots, the three-year-old and the 24-year-old Platycodon roots cultivated in a local farm were extracted with ethyl ether by SDE method. 54.71㎎% and 80.01㎎% of volatile components were collected in the three-year-old and in 24-year-old Platycodon roots, respectively. As a result of GC/MS(TIC) analysis, 24 and 28 compounds were identified, respectively. The amounts of volatile components such as hexanol, trans-2-hexenol and nonanal in 24-year-old roots were detected above ten times than those in 3-year-old roots. The Volatiles of 24-year-old roots were fractionated by SCC and identified by GC/MS to be 10 hydrocarbons, 8 alcohols, 10 aldehydes, 5 esters, 6 acids and 1 unknown compound as the major components. The species and total amounts of volatile component in 24-year-old Platycodon roots were considered to be higher than those in 3-year-old Platycodon roots. * Abbreviations 1. Platycodora : platycodon grandiflorus (jacquin) A. De Candolle. 2. SDE : Simultaneous Distillation Extraction 3. SCC : Silicagel Column Chromatography 4. GC : gas chromatography 5. GC/MS : Gas Chromatography-Mass Spectrometer 6. TIC : Total Ion Chromatography

HSS Roll의 흑피형성 및 표면거칠음 거동

최진원(Jin-Won CHOI),정진환(Jin Hwan CHUNG) 한국소성가공학회 1999 압연 심포지엄 Vol.1999 No.8

열간압연용 Ni-Grain Roll의 표면거칠음 및 전동피로 거동

최진원(Jin-Won Choi),정진환(Jin-Hwan Chung),정병일(Byong-Ill Jung),이희춘(Hui Choon Lee) 한국소성가공학회 1996 압연 심포지엄 Vol.1996 No.9

페라이트-베이나이트 복합조직 고강도 열연강판의 신장플랜지 특성에 관한 연구

조열래,정진환,구황회,김인배,Cho, Yeol-Rae,Chung, Jin-Hwan,Koo, Hwang-Hoe,Kim, In-Bae 한국재료학회 1999 한국재료학회지 Vol.9 No.12

자동차 휠, 멤버 등의 소재로 사용되는 인장강도 580MPa급 열연강판의 버링성형성을 향상시키기 위하여 강판의 신장 플랜지성(stretch-flangeability)에 대한 미세조직 및 열간압연후 냉각인자의 영향에 대하여 검토하였다. 열간압연후 3단 냉각제어 및 권취온도의 극저온화에 의하여 신장플랜지성이 우수한 페라이트-베이나이트 복합조직강의 제조가 가능하며, 3단 제어냉각에서 강판의 온도를 $Ar_3$ 직하의 페라이트변태역에서 일정 시간 유지하면 페라이트 변태 및 NbC의 석출이 조장됨을 확인하였다. 페라이트-베이나이트 복합조직 열연강판의 우수한 신장플랜지성은 3단 냉각 및 극저온 권취에 의한 등축 페라이트 분율의 증가, 입계 세멘타이트의 미세화 및 구성 상간의 경도차 저하에 의하여 타발공정에서의 미소균열 생성 및 전파가 억제되기 때문인 것으로 판단되었다. 아울러 0.08wt%C-1.5wt%Mn-0.04wt%Nb 성분계를 이용하여 제조된 인장강도 580MPa급 페라이트-베이나이트 복합조직 열연강판은 연신율 22% 이상, 구멍확장율 (신장플랜지성) 90% 이상의 재질특성을 가지며, 버링비 60% 이상의 자동차 휠 디스크에 적용 가능한 것으로 판명되었다. The effect of microstructures on the strength-flangeability of Nb bearing hot-rolled high strength steel was investigated in order to improve the strength-flangeability of conventional TS 580MPa grades HSLA steel for the automotive wheel disc. The low temperature coiling method using 3-step controlled cooling pattern after hot rolling was effective to produce the Nb-bearing high strength steel with the polygonal ferrite and bainite duplex microstructures. It was suggested that the suppressed precipitation of grain boundary cementites and the decreased hardness difference between ferrite matrix and bainite cause the excellent stretch-flangeability of ferrite-bainite duplex microstructure steel. Therefore, the formation and propagation of microcracks were suppressed relative to the conventional HSLA steel with ferrite and pearlite microstructure. In addition, the elongation was improved as compared with that of hot-rolled steel sheets using conventional early cooling pattern because the volume fraction of polygonal ferrite was increased.

열간압연용 Ni - Grain Roll 의 표면거칠음 및 전동피로 거동

최진원,정진환,정병일,이희춘 ( Jin Won Choi,Jin Hwan Chung,Byong Ill Jung,Hui Choon Lee ) 대한금속재료학회 1996 압연기술의 현재와 미래 Vol.- No.-