섬유화 온도 변화에 따른 E-glass fiber의 물리적 특성

이지선,이미재,임태영,이영진,전대우,현승균,김진호,Lee, Ji-Sun,Lee, MiJai,Lim, Tae-Young,Lee, Youngjin,Jeon, Dae-Woo,Hyun, Soong-Keun,Kim, Jin-Ho 한국재료학회 2017 한국재료학회지 Vol.27 No.1

E (Electric) -glass fibers are the most widely used glass fibers, taking up 90 % of the long glass fiber market. However, very few papers have appeared on the physical characteristics of E-glass fibers and how they depend on the fiberizing temperature of fiber spinning. Glass fiber was fabricated via continuous spinning process using bulk E-glass. In order to fabricate the E-glass specimen, raw materials were put into a Pt crucible and melted at $1550^{\circ}C$ for 2hrs; mixture was then annealed at $621{\pm}10^{\circ}C$ for 2hrs. The transmittance and adaptable temperature for spinning of the bulk marble glass were characterized using a UV-visible spectrometer and a viscometer. Continuous spinning was carried out using direct melting spinning equipment as a function of the fiberizing temperature in the range of $1175{\sim}1250^{\circ}C$, while the winder speed was fixed at 500 rpm. Subsequently we investigated the physical properties of the E-glass fiber. The average diameter of the synthesized glass fiber was measured by optical microscope. The mechanical properties of the fiber were confirmed using a UTM (universal materials testing machine); the maximum tensile strength was measured and found to be $1843{\pm}449MPa$ at $1225^{\circ}C$.

신생아기에 새로운 CPS1 유전자 돌연변이가 확인되고, 간세포이식 시행 받은 Carbamoyl phosphatase synthetase 1 deficiency 1례

이지선,양아람,김진섭,박형두,이상훈,이석구,조성윤,진동규,Lee, Jisun,Yang, Aram,Kim, Jinsup,Park, Hyung-Doo,Lee, Sanghoon,Lee, Suk-Koo,Cho, Sung Yoon,Jin, Dong-Kyu 대한유전성대사질환학회 2017 대한유전성대사질환학회지 Vol.17 No.1

Carbamoyl phosphate synthetase 1 (CPS1) 결핍은 요소회로 이상 질환 중 하나로 상염색체 열성으로 유전되며 2q35 염색체에 존재하는 CPS1 유전자 변이로 발생된다. CPS1의 완전한 결핍을 가진 경우 신생아 시기에 빠르게 진행하는 고암모니아혈증으로 발현한다. 신생아 시기의 심한 고암모니아혈증은 즉각적인 치료를 받지 않을 시 심각한 뇌 손상, 혼수, 사망에 이르기에 진단 시 응급 투석과 체계적인 집중 치료가 필요하다. 본 증례는 생후 4일 째 신생아실에서 발열, 경련, 고암모니아혈증이 확인되어 생화학적, 분자유전학적 방법으로 두 개의 새로운 변이 c.1117G>C (p.Ala373 Pro)와 c.1883G>T (p.Gly628Val)가 이형접합체로 발견되고 CPS1 결핍이 진단된 신생아에서 응급 투석 및 집중치료와 함께 궁극적인 치료인 간이식 전 간세포이식술을 생후 1개월에 시행하여 반복적인 고암모니아혈증 발생을 막고 불가역적인 신경손상을 예방하여 현재 생후 6개월까지 단기간 경과관찰 결과 성장과 발달 및 신경학적 예후가 좋음을 보고하는 바이다. Carbamoyl phosphate synthetase 1 deficiency (CPS1D) is an autosomal recessive disorder of the urea cycle that causes hyperammonemia. Two forms of CPS1D are recognized: a lethal neonatal type and a less severe, delayed-onset type. Neonatal CPS1D cases often present their symptoms within the first days of life. Delayed-onset cases are predominantly adolescents or adults, and infantile delayed-onset cases are rare. Severe hyperammonemia in the neonatal period leads to serious brain damage, coma, and death if not treated promptly. Therefore, early diagnosis and acute treatment are crucial. Despite the improvement of treatments, including continuous hemodialysis, ammonia-lowering agents, and a low-protein diet, the overall outcome of severe forms of hyperammonemia often remains disappointing. As the liver is the only organ in which ammonia is converted into urea, liver transplantation has been considered as an elegant and radical alternative therapy to classical dietary and medical therapies. However, liver transplantation has many disadvantages, such as a considerable risk for technical complications and perioperative metabolic derangement, especially in neonates. Additionally, there is a lack of suitable donor organs in most countries. According to recent studies, liver cell transplantation is a therapeutic option and serves as a bridge to liver transplantation. Here, we report a Korean CPS1D patient with novel mutations in CPS1 who was treated by liver cell transplantation after being diagnosed in the neonatal period and showed a good neurodevelopmental outcome at the last follow-up at six months of age.

붕소를 함유하지 않는 E-glass fiber의 제조 및 특성에 대한 연구

이지선,임태영,이요셉,이미재,황종희,김진호,현승균,Lee, Ji-Sun,Lim, Tae-Young,Lee, Yo-Sep,Lee, Mi-Jai,Hwang, Jonghee,Kim, Jin-Ho,Hyun, Soong-Keun 한국결정성장학회 2013 韓國結晶成長學會誌 Vol.23 No.1

E-glass 섬유는 항공기, 자동차, 레져기구의 복합재료 보강용으로 가장 널리 사용되는 유리섬유이다. 그러나 최근 E-glass 섬유의 원재료비 상승, 환경문제 및 화학적 저항성과 기계적 특성을 향상시키기 위해 산화붕소 함량을 8 %에서 0(제로)까지 감소시키는(소위 'Boron free E-glass'라고 불리는) 연구가 진행되고 있다. 본 연구에서는 'BF(Boron free E-glass)' 조성의 벌크유리와 섬유유리를 제조하고, 열적특성 및 광학적특성을 평가하였다. 5~10 %의 서로 다른 알루미나 함량을 갖는 배치를 $1550^{\circ}C$에서 2시간 용융하여 'BF(Boron free E-glass)'가 얻어졌고, 81~86 %의 높은 가시광투과율, $4.2{\sim}4.9{\times}10^{-6}/^{\circ}C$의 낮은 열팽창계수, $907{\sim}928^{\circ}C$의 연화점을 갖는 투명하고 맑은 유리가 얻어졌다. 'BF' 섬유 시편에 대한 화학적내구성 시험에 있어서는 알루미나 함량이 높아질수록 더 좋은 침식저항성을 나타냄을 확인할 수 있었다. E-glass fiber is the most widely used glass fiber for reinforced composite materials of aircrafts, automobiles and leisure equipments. But recently researches are being progressed to reduce boric oxide from 8 % to 0 (zero), as is called 'Boron free E-glass', because of increasing material cost, environmental problem, and improving chemical resistance and mechanical properties of E-glass fiber. In this study, we fabricated the bulk glass and fiber glass of 'Boron free E-glass (BF) compositions', and characterized thermal properties and optical properties. 'Boron free E-glass (BF)' was obtained by the melting of mixed batch materials at $1550^{\circ}C$ for 2 hrs with different $Al_2O_3$ compositions 5~10 %. We obtained transparent clear glass with high visible light transmittance value of 81~86 %, and low thermal expansion coefficient of $4.2{\sim}4.9{\times}10^{-6}/^{\circ}C$ and softening point of $907{\sim}928^{\circ}C$. For the chemical resistance test of 'BF' fiber samples, we identified that the higher alumina contents gives the better corrosion resistance of glass fiber.

사암계 석탄폐석을 활용한 E-glass fiber 조성의 유리 제조 및 특성

이지선,임태영,이미재,황종희,김진호,현승균,Lee, Ji-Sun,Lim, Tae-Young,Lee, Mi-Jai,Hwang, Jonghee,Kim, Jin-Ho,Hyun, Soong-Keun 한국결정성장학회 2013 韓國結晶成長學會誌 Vol.23 No.4

삼척도계지역의 탄광에서 석탄채굴시에 부산물로 발생되는 사암계 석탄폐석을 원료로 사용하여 E-glass fiber 조성의 유리를 제조하였다. 본 연구에서는 카본함량이 비교적 적은 실리카-알루미나질의 사암계 석탄폐석을 사용하였으며, 폐석의 투입량을 0~35 %까지 변화시켰다. 서로 다른 석탄폐석 투입량을 갖는 배치원료를 $1550^{\circ}C$에서 2시간 용융하여 E-glass조성을 갖는 투명하고 맑은 유리가 얻어졌고, 81~84 %의 높은 가시광투과율, $5.39{\sim}5.61{\times}10^{-6}/^{\circ}C$의 열팽창계수, 851~$860^{\circ}C$의 연화점을 나타내었다. 유리섬유 시편은 $1150^{\circ}C$에서 섬유인상장치를 통해 얻어졌고, 복합재료의 보강용 유리섬유로서 내화학성 시험과 기계적 특성평가를 위한 인장강도를 측정하였다. 그 결과 석탄폐석을 사용한 E-glass fiber의 특성이 석탄폐석을 사용하지 않은 보통 E-glass 섬유에 비해 충분히 양호한 특성을 나타내어 E-glass 섬유용 원료로서 석탄폐석의 활용가능성을 확인할 수 있었다. The glass of E-glass fiber composition was fabricated by using refused coal ore which is obtained as by-product from Dogye coal mine in Samcheok. We used silica-alumina refused coal ore which has low carbon content relatively, and the amount of refused coal ore has been changed from 0 to 35 % in batch composition. E-glass was fabricated by the melting of mixed batch materials at $1550^{\circ}C$ for 2 hrs with different refused coal ore composition of 0~35 %. We obtained a transparent and clear glass with high visible light transmittance value of 81~84%, thermal expansion coefficient of $5.39{\sim}5.61{\times}10^{-6}/^{\circ}C$ and softening point of $851{\sim}860^{\circ}C$. The glass fiber samples were also obtained through fiberizing equipment at $1150^{\circ}C$, and tested chemical resistance and tensile strength to evaluate the mechanical property as a reinforced glass fiber of composite material. As the result, we identified the properties of E-glass fiber by using refused coal ore are plenty good enough compare to that of normal E-glass without refused coal ore, and confirmed the possibility of refused coal ore as for the raw material of E-glass fiber.

Effects of Impurity Ions on the Synthesis of Hollow Silica

이지선,문성철,이영철,윤창번,Seong-Eui Lee 한국전기전자재료학회 2018 Transactions on Electrical and Electronic Material Vol.19 No.1

In this study, we aimed to synthesize plate shaped hollow silica powder using Mg(OH) 2 as an inorganic core particle that canbe removed conveniently through an acid-based process without using any additional organic solvents or heat treatment. Wealso elucidated the eff ects of the impurity ions formed during the synthesis process on the properties of the hollow silica. Plate type hollow silica could be synthesized successfully from sodium silicate by the precipitation method while usingMg(OH) 2 as the template. A silica shell was formed on the Mg(OH) 2 particles, and a sulfuric acid treatment was performed toremove the template, yielding hollow silica. The impurity ions generated during the synthesis process resulted in undesirablespherical silica particles, as they acted as additional silica formation sites. The number of silica particles formed reduced witha decrease in the number of impurity ions in the reaction solution; this, in turn, increased the thickness of the silica shell. This result indicated that, as the amount of impurity ions in the reaction solution is reduced, silica reaction sites other thanthe inorganic Mg(OH) 2 particles are also minimized. As a result, the added silica precursors will not be consumed for theformation of the silica particles and will react completely on the Mg(OH) 2 core particles to form shells with increased thickness. Finally, we also believe that NH 4 OH, which contains the OH group, would be a suitable another silica formation site.

단신;1,2,3,4-Tetrahydroisoquinoline 유도체의 합성

이지선,이채호,Lee, Ji Sun,Lee, Chai Ho 대한화학회 2001 대한화학회지 Vol.45 No.1

사업용 화물자동차의 교통사고 예방체계 강화방안 연구

이지선,정승주,허진수,이창섭,Lee, Ji-Seon,Jeong, Seung-Ju,Heo, Jin-Su,Lee, Chang-Seop 대한교통학회 2016 교통 기술과 정책 Vol.13 No.3

선탄 경석 재활용 원료를 이용한 유리 용융 특성

이지선,김선욱,라용호,이영진,임태영,황종희,전대우,김진호,Lee, Ji-Sun,Kim, Sun-Woog,Ra, Yong-Ho,Lee, Youngjin,Lim, Tae-Young,Hwang, Jonghee,Jeon, Dae-Woo,Kim, Jin-Ho 한국재료학회 2019 한국재료학회지 Vol.29 No.11

In this study, the glass melting properties are evaluated to examine the possibility of using refused coal ore as replacement for ceramic materials. To fabricate the glass, refused coal ore with calcium carbonate and sodium carbonate in it (which are added as supplementary materials) is put into an alumina crucible, melted at $1,200{\sim}1,500^{\circ}C$ for 1 hr, and then annealed at $600^{\circ}C$ for 2 hrs. We fabricate a black colored glass. The properties of the glass are measured by XRD (X-ray diffractometry) and TG-DTA (thermogravimetry-differential thermal analysis). Glass samples manufactured at more than $1,300^{\circ}C$ with more than 60 % of refused coal ore are found by XRD to be non-crystalline in nature. In the case of the glass sample with 40 % of refused coal ore, from the sample melted at $1,200^{\circ}C$, a sodium aluminum phosphate peak, a disodium calcium silicate peak, and an unknown peak are observed. On the other hand, in the sample melted at $1,300^{\circ}C$, only the sodium aluminum phosphate peak and unknown peak are observed. And, peak changes that affect crystallization of the glass according to melting temperature are found. Therefore, it is concluded that glass with refused coal ore has good melting conditions at more than $1,200^{\circ}C$ and so can be applied to the construction field for materials such as glass tile, foamed glass panels, etc.

활성대조군을 이용한 두 군 설계와 위약군을 포함한 세 군 설계의 비열등성 시험

이지선,김동재,Lee, Ji-Sun,Kim, Dong-Jae 한국통계학회 2008 응용통계연구 Vol.21 No.6

비열등성 시험시에 치료군(treatment group)과 활성대조군(active control group)을 이용한 모형으로 Hauschke 등 (1999)이 제안한 모수적 검정법이 있다. 이 방법은 위약군(placebo group)과 직접적인 비교가 불가능하므로 Pigeot 등 (2003)이 세 군으로 확장한 검정법을 제안하였다. 그러나 이와 같은 두 검정법은 구체적인 분포가정이 필요하다. 이런 단점을 보완하기 위하여 본 논문에서는 비모수적 방법으로서 두 군 설계에 Wilcoxon 순위합 검정(Wilcoxon, 1945)을 이용한 방법을, 세 군 설계에 Scheirer 등 (1976)이 제안한 선형대비검정을 확장한 새로운 방법을 제안한다. 또한 모의실험을 통하여 모수적 방법과 비모수적 방법간의 검정력을 비교하였다. Two-arm non-inferiority trials is often applied to parametric procedure suggested by Hauschke et al. (1999). Since this design does not allow a direct comparison of a new treatment group with placebo group, parametric procedure in a three-arm non-inferiority trial with a placebo group was suggested by Pigeot et al. (2003). But, procedures in these designs are necessary for distribution assumptions. Therefore we propose, in this paper, non parametric procedures employing Wilcoxon rank sum test in a two-arm design and linear contrast test suggested by Scheirer et al. (1976) in a three-arm design. The proposed nonparametric procedures and parametric procedures are compared by Monte Carlo simulation study.

한국인의 항결핵제에 의한 간독성 위험인자 예측

이지선,김현아,조은,이옥상,임성실,Lee, Ji-Sun,Kim, Hyun-Ah,Cho, Eun,Lee, Ok-Sang,Lim, Sung-Cil 대한약학회 2011 약학회지 Vol.55 No.4

Standard combination chemotherapy including isoniazid, rifampin, pyrazinamide, and ethambutol is very effective against tuberculosis. But, these medicines can cause hepatotoxicity which is the main reason for treatment interruption or change in drug regimen. In order to identify risk factors associated with hepatotoxcity in Koreans and assess elevated baseline LFTs' contributions to hepatotoxicity, a retrospective case control study was performed. The medical records of 277 patients who diagnosed with tuberculosis at a community hospital from January 1st, 2007 to June 30th, 2010 were reviewed. Patients were categorized into 3 groups (non toxic group, patients without increase in LFT levels; mild to moderate hepatotoxic group and severe hepatotoxic group). And the correlation between risk factors and hepatotoxicity was analyzed by using SPSS program. The overall incidence of hepatotoxicity was 18% and 8.7% of patients developed severe toxicity. Patients in the severe toxic group had the longest treatment period among the three groups. In 75% of severe toxic group, hepatotoxicity occurred within 18.3 days after starting medication. Hypoalbuminemia (serum albumin <3 g/dl) was a significant risk factor for development of severe toxicity. Elevated baseline transaminase (except ALT), total bilirubin, and preexisting hepatitis were also risk factors which were more than twice as likely to increase risk of severe hepatotoxicity (p>0.05). In conclusion, hypoalbuminemia (serum albumin level <3 g/dl) was a significant risk factor for anti-tuberculosis druginduced severe toxicity. Therefore, before starting antituberculosis chemotherapy, serum albumin level should be assessed at baseline. In high-risk patients (hypoalbuminemia, elevated LFTs) for hepatotoxicty, liver function should be closely monitored up to at least 21 days after taking medication.