Poly(lactic acid) 용융방사공정의 동역학 해석

오태환(Tae Hwan Oh),김성철(Seong Cheol Kim) 한국청정기술학회 2009 청정기술 Vol.15 No.4

Poly(lactic acid) (PLA) 용융방사공정의 속도, 직경, 온도, 인장응력 분포를 구하기 위해 수치모사를 실시하였다. 유한차분법을 이용하여 반지름 방향으로의 온도분포곡선을 구하였다. 방사속도 1 km/min에서 5km/min까지 방사속도에 따른 PLA 방사공정의 변화와 poly(ethylene terephthalate) (PET)와의 거동을 비교해 보았고, 방사공정변수가 섬유 중심부와 표면과의 온도차에 미치는 영향을 살펴보았다. PLA는 용융온도가 PET에 비해 낮음에도 불구하고 동일 방사조건에서 더딘 냉각속도를 보였고 방사거리에 따른 방사속도의 증가도 PET가 더 빠른 양상을 나타내었다. PLA의 섬유중심부와 섬유표면과의 온도차는 약 4.6 K에 이르렀는데, 이는 PET의 10.4 K에 비하여 낮은 값이다. PLA 섬유중심부와 표면과의 온도차는 냉각풍속도와 방사온도가 증가할수록 증가하였고, 냉각풍 온도가 감소할수록 증가하는 경향을 나타내었다. Profiles development of melt spinning process of poly(lactic acid) (PLA) was simulated via a numerical method and the radial temperature distribution was calculated using finite difference method. The spinning speed ranged from 1 km/min to 5 km/min was analyzed and the effect of spinning conditions on the radial temperature distribution was investigated. At low spinning speed, the difference between PLA and poly(ethylene terephthalate) (PET) was relatively small. As the spinning speed increased, the difference in velocity profile became prominent. PLA showed a slower spinning speed than PET and solidified more slowly. The temperature difference between the core and surface of the PLA filament reached 4.6 K, which was less than that of PET filament with a difference of 10.4 K. The radial temperature difference increased with increasing the cooling-air velocity and the spinning temperature.

남북철도 연결을 위한 철도노반 동상방지층 검토

오태환(Tae Hwan Oh),노병국(Byoung Kck Roh),양인동(In Dong Yang),백진호(Jin Ho Baek),안승우(Seung Woo Ahn) 한국철도학회 2019 한국철도학회 학술발표대회논문집 Vol.2019 No.11

咳嗽 脈診에 關한 文獻的 考察

吳泰煥(Tae Hwan Oh),鄭昇杞(Sung Gi Jung),李珩九(Hyung Koo Rhee) 대한한의학회 1988 대한한의학회지 Vol.9 No.1

셰일암을 이용한 고속철도 암석쌓기 장기침하 연구

오태환(Tae-hwan Oh),김종주(Jong-Ju Kim),이성혁(Seong-Hyeok Lee),조국환(Kook-Hwan Cho) 한국철도학회 2016 한국철도학회 학술발표대회논문집 Vol.2016 No.10

대구, 경주, 울산지역은 지질 특성상 퇴적암 셰일이 주를 이루며, 터널굴착시 발생하는 버력(셰일)을 유용하여 고속철도 암석쌓기로 사업효과를 극대화하였다. 콘크리트궤도의 경우 허용침하량이 30mm 이하로 쌓기재료는 매우 엄격하게 관리되어야 하며, 침하발생시 유지보수 측면에서 시간과 노력, 비용 등이 많이 소요된다. 이 지역 셰일의 경우 1 년 이상 풍수에 직접영향을 받는 자연환경에 노출될 경우 층리면을 따라 부서지는 슬레이킹 현상이 발생되나, ISRM 2 주기 내구성 시험결과는 층리가 없는 암석을 채취하여 시험하므로 높게 평가된다. 따라서, 암석쌓기 재료로서 과대평가 될 수 있는 셰일에 대한 내구성 품질시험 기준과 암석쌓기 입도요건, 셰일 암석쌓기 적용개소에 대한 기초자료를 제시하였다. The sedimentary rock shale is mainly constituted in the region of Daegu, Gyeongju and Ulsan. Those shales are usually used as a embankment material to save construction costs from tunnel excavation. The allowable settlement of concrete slab track is only 30mm and very strictly controlled. If settlement is over the allowable value, costs for maintenance are much higher than ballast track bed. The shale rock in this region has easily breakable characteristics after 1-year exposed but those characteristics cannot be investigated from cycle durability test result.. Thus, the standards of durability quality test for the shale that could be overrated as an embankment material. The basic data for the requirements of a particle size and applicable shale embankment sections are provided in this study.

폐적(肺積) 폐옹(肺癰) 폐저(肺疽) 폐암(肺癌)에 관(關)한 문헌적(文獻的) 고찰(考察)

한재수,오태환,정승기,이형구,Han, Jae-Soo,Oh, Tae-Hwan,Jung, Sung-Gi,Rhee, Hyung-Koo 대한한방내과학회 1991 大韓韓方內科學會誌 Vol.12 No.2

This study has been carried out to investigate Pyu-Juk ( 肺積 ), Pyu-Ong ( 肺癰 ), Pyu-Ju ( 肺疽 ), Pyu-Am ( 肺癌 ) by referring to 56 literatures. The results were obtained as follows; 1. The treatllent-method of Pyu-Juk ( 肺積 ) are Ik Ki ( 益氣 ), SuI Yem Wha ( 洩陰火 ), So Juk ( 消積 ), Wha Juk ( 化積 ), Son Juk ( 損積 ), Ma Juk ( 摩積 ) Jo Chil Gi ( 調七氣 ), and herbs are Sik Bun Tang ( 息賁湯 ), Sik Bun Hwan ( 息賁丸 ), O Juk Hwan ( 五積丸 ), Ban ha Tang ( 半夏湯 ), Gil Gyung Tang ( 桔梗湯 ), Dae Chil Gi Tang ( 大七氣湯 ), Chil Gi Hwan ( 七氣湯 ) , Ga Gam Sik BlDl Hwan ( 加減息賁丸 ), Bil Rang San ( 檳郞散 ). 2. The treatment-method of Pyu-Ong ( 肺癰 ) Yang pyu ( 養肺 ), Yang Hyul ( 養血 ), Yang Gi ( 陽氣 ), Chung Geam Youn Pye ( 淸金潤肺 ), Hal Dam Bae Nong ( 豁痰排膿 ), Saeng Gi ( 生肌 ), herbs are Gil Gyung Tang ( 桔梗湯 ), Jung Ryuk Dae Jo Sa Pyu Tang ( ??大棗瀉肺湯 ), Chung Geom Wy Gyung Tang ( 千金 葦莖湯 ) Hwang Gi tang ( 黃嗜湯 ), Hyun Sam Chung Pyu Eum ( 玄蔘淸肺飮 ), Sip Mi Hwan ( 十味丸 ), Gil Gyung Baek San ( 桔梗白散 ), So Hong Eum ( 消膿飮 ), Sam Gi Bo Pyu Tang ( 蔘嗜補肺湯 ), sam Chul Gun Bi Tang ( 蔘朮健脾湯 ), Chung Pyu Gil Gyung Tang ( 淸肺桔梗湯 ), Yu Sung Hwan ( 如聖丸 ). 3. The treatment-method of Pyu-Ju ( 肺疽 ) are Be Bi ( 補脾 ), Bo Pyu ( 補肺 ), herbs are Hwang Gi Gum Jung Tang( 黃嗜補裨湯 ), lnSamBoPyuSan (人蔘補肺散) 4. The treatment-method of Pyu-Am ( 肺癌 ) are Bal Han ( 發汗 ), Chung Yul Hae Dok ( 淸熱解毒 ), Gang Hwa Do Dam ( 降火導痰 ), Hwa Rak Hwa a ( 和絡化瘀 ) Ik Pyu ( 益肺 ), Gun Bi ( 健脾 ), Ja Eum Yun Pyu ( 滋陰潤肺 ), Gi Hu Yang Bo ( 氣虛兩補 ), herbs are Gyul Yua Hae Dok Tang ( 莖熱解毒湯 ), Gang Hwa Jae ( 降火劑 ), Chil Yul Do Dam Tang ( 治熱導痰湯 ), Chong Ho Byul Gap Tang ( 靑蒿鱉甲湯 ), Ga gam Gil Gyung Tang ( 加減桔梗湯 ), Sang Mak San ( 生脈散), Yuk Mi Ji Hwang Tang ( 六味地黃湯 ), Baek Hap Go Geum Tang ( 百合固金湯 ), Dae Be Won Jun ( 大補元煎 ), Ga Mi Jae Che Bo Pyu Tang ( 加味載體補肺湯 ).

원저 : 삼요탕 및 가미삼요탕의 효능에 관한 연구 ( Original Article : A Study of the Effects on Samyutang and Gamisamyutang )

윤태영(Tae Young Yun),오태환(Tae Hwan Oh),정성기(Sung Ki Jung),이형구(Hyung Koo Lee) 경희대학교 경희의료원 1992 慶熙醫學 Vol.8 No.1

외감해수(外感咳嗽)의 동(東) 서(西) 의학적(醫學的) 비교(比較)에 관(關)한 문헌적(文獻的) 고찰(考察)

김낙기,오태환,정승기,이형구,Kim, Nak-Gi,Oh, Tae-Hwan,Jung, Sung-Gi,Rhee, Hyung-Koo 대한한방내과학회 1992 大韓韓方內科學會誌 Vol.13 No.2

This study has been carried out to compare the exogenous cough(外感咳嗽) to western medicine. The results were as follows: 1. The exogenous cough(外感咳嗽) on the oriental medicine was similar to U.R.I., Infectious pneumonia, acute bronchitis on the western medicine and acute bronchitis was most similar to the exogenous cough(外感咳嗽). 2. The exogenous cough(外感咳嗽) was caused by the six devils of the environment(六淫) involving the lung and clinically divided into poonghan cough(風寒咳嗽), poongyul cough(風熱咳嗽) and poongjo cough(風燥咳嗽). 3. The symptom of the exogenous cough(外感咳嗽). a. poonghan cough(風寒咳嗽): sputum-rare and white color, laryngeal voice and tickel, stuffed-up and running nose, chilling and fever, headache and generalache, seoltae(舌苔) - thin and white color, pulse - boogin(浮緊). b. poongyul cough(風熱咳嗽): sputum-thick and yellow color, difficult expectoration sore thraot and thirsty, fever and chilling, sweating or headache, seoltae(舌苔) - thin and white color, pulse - boosak(浮數). c. poongjo cough (風燥咳嗽): dry cough with no or a little sputum and difficult expectoration, chest pain, dryness on the pharynx and lips, chilling and fever, seoltae(舌苔) - thin and dry, yellow color, pulse - sesak(細數) 4. The treatment of the exogenous cough(外感咳嗽). a. poonghan cough(風寒咳嗽) : sopoongsanhan sunpyuegihae (疎風散寒 宣肺止咳) b. poongyul cough(風熱咳嗽) : sopoongcheongyul sunpyuegihae (疎風淸熱 宣肺止咳) c. poongjo cough(風操咳嗽) : chungpyueyunjo saenggingihae (淸肺潤燥 生津止咳)

풍수(風嗽)의 원인(原因) 증상(症狀) 치법(治法) 치방(治方)에 관(關)한 문헌적(文獻的) 고찰(考察)

김락기,오태환,정승기,이형구,Kim, Rack-Ki,Oh, Tae-Hwan,Jung, Sung-Gi,Rhee, Hyung-Koo 대한한방내과학회 1991 大韓韓方內科學會誌 Vol.12 No.2

This study has been carried out to investigate the cause symptom and treatment of wind-coughing ( 風嗽 ) by referring to 38 literatures. The results were obtained as follows; 1. The factors causing wind-coughing ( 風嗽 ) is wind-air. The 1st factors are mistaking of transport lung-air ( 肺氣不宣 ) and cleaning lung (肺失淸肅). 2. The symptom of wind-coughing ( 風嗽 ) is as follows. Bi Saek Sung Jung ( 鼻塞聲重 ), Gu Gun Hu Yang ( 口乾喉痒 ), A Mi Kung I Hae ( 語未竟而咳 ), Maek Bu ( 脈浮 ), Jeang Han Jang Yul ( 憎寒壯熱 ), Ja Han OU Pung ( 自汗惡風 ), Bun Jo ( 煩躁 ), Bi Ryu Chung Chae ( 鼻流淸?), Ya Jung 11 Jyung ( 夜重日輕 ). 3. The treatment-method of wind-coughing ( 風嗽 ) is as follow. Bal San Bul Ga Ha ( 發散 不可下 ), So Pung San Han ( 疏風散寒 ), Chung Yul ( 淸熱 ), Sun Pae Ji Hae ( 宣肺止咳 ). 4. The treatment-herbs of wind-coughing ( 風嗽 ) is as follow. Kwan Dong Hwa San ( 款冬花散 ), Gun Bi Cho San ( 金沸草散 ), Sam Yo Tang ( 三拗湯 ), Ji Hae San ( 止嗽散 ), Hang So San ( 杏蘇散), Sang Kuk Yeam ( 桑菊飮).

열가공 온도에 따른 TPU 복합직물의 물성 변화 연구

장순호,오태환,김성훈,Jang, Soon Ho,Oh, Tae Hwan,Kim, Seong Hun 한국섬유공학회 2017 한국섬유공학회지 Vol.54 No.1

In this study, the tensile properties and water repellency of heat-treated thermoplastic polyurethane (TPU) composite fabric were investigated and compared with those of untreated TPU composite fabric. The TPU composite fabric was prepared using a TPU coated polyester filament (PET FY) with a volume ratio of 33%:67% (PET FY:TPU). The properties of the TPU composite fabric were found to be affected by heat treatment to various extents depending of the temperature. A maximum tenacity of 34.5 MPa, a contact angle of $130^{\circ}$ (indicative of good water repellency), and an ISO grade of 5 (indicative of high resistance to surface wetting) were obtained at a heat-treating temperature of $190^{\circ}C$.

$^1H-NMR$과 WAXS를 이용한 폴리(트리메틸렌 테레프탈레이트)/폴리(트리메틸렌 나프탈레이트) (50/50) 블렌드의 에스터 교 환반응 연구

최재원,오태환,김영호,Choi, Jae-Won,Oh, Tae-Hwan,Kim, Young-Ho 한국섬유공학회 2005 한국섬유공학회지 Vol.42 No.5

Poly(trimethylene terephthalate) (PIT) and poly(trimethylene naphthalate) (PTN) blends of 50/50 weight ratio, T5N5, were prepared by solution blending-precipitation method, and the effect of melting time on the degree of randomness, sequence length, and crystalline structure of melt-pressed blends obtained by melting T5N5 on a hot stage at $260^{\circ}C$ for different times and quenching into liquid nitrogen was studied using DSC, $^1H-NMR$ and WAXS. The T5N5 blend showed two $T_gs$ corresponding to that of PTT and PTN, which indicated that PTT and PTN were immiscible. But the melt-pressed blends melted at $260^{\circ}C$ for 2 minutes or more showed single $T_g$ indicating that the system became miscible. $^1H-NMR$ analysis confirmed that the blends became block copolymers and that the degree of randomness increased as melting time increased. The sequence length of PTT component was larger than that of PTN in the resultant copolymer. Although PTT and PTN were present in the same amount in the blend, PTT component crystallized more easily than the PTN component due to the larger block length of PTT. The crystalline structure of the component polymers was the same as that of homopolymers. The WAXS patterns showed that the crystalline structure of PTN in the melt-pressed blends was $\beta-form$ when they were annealed at $180^{\circ}C$ but it was a-form when annealed at $140^{\circ}C$, exhibiting the same behavior as homo PTN.