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초음파 주파수 및 반응조건 변화에 따른 나프탈렌 분해효율과 OH 라디칼의 발생량 비교
박종성(Jong Sung Park),박소영(So Young Park),오재일(Jei Ll Oh),정상조(Sang Jo Jeong),이민주(Min Ju Lee),허남국(Nam Guk Her) 大韓環境工學會 2009 대한환경공학회지 Vol.31 No.2
나프탈렌은 휘발성이 있는 소수성 물질로 발암유발 가능성이 있고, 수생태계에 심각한 영향을 미친다. 본 연구는 초음파의 주파수 및 반응조건별 나프탈렌 분해효율과 OH 라디칼 변화량을 조사하였다. C-18 역상칼럼을 이용한 LC/FLD (1200 series, Agilent)로 나프탈렌을 분석한 결과 MDL (Method detection limit)은 0.01 ppm이었다. 초음파 조사 동안 휘발된 나프탈렌은 거의 검출되지 않았고(0.05 ppm 이하), 반응조 덮개 개폐별 나프탈렌 분해효율은 거의 차이를 보이지 않았다(1% 이내). 초음파 반응온도가 증가할수록 나프탈렌 제거효율은 감소하는 경향(15℃: 95%→40℃: 85%)을 보였고, pH가 낮을수록 나프탈렌 분해효율이 증가(pH 12: 84%→pH 3: 95.6%)하였다. 나프탈렌 초기농도의 감소에 따라 반응속도는 증가하는 경향을 보여주었다(2.5 ppm: 27.3×10(-3) min(-1), 5 ppm: 22.7×10(-3) min(-1), 10 ppm: 19.0×10(-3) min(-1)). 동일한 초음파 조건(2.5 ppm 나프탈렌, 0.075 W/mL, 20℃, pH 6.8)에서 28 kHz의 분해효율이 132 kHz보다 약 1.46배 높았고(132 kHz: 56%, 28 kHz: 82.7%), 유사 일차반응 속도상수(k1)도 약 2.3배 높게 나타났다(132 kHz: 2.4×10(-3) min(-1), 28 kHz: 5.0×10(-3) min(-1)). 초음파 조사 10분 후 H₂O₂ 농도는 132 kHz가 28 kHz보다 약 7.2배 높았지만(132 kHz: 0.36 ppm, 28 kHz: 0.05 ppm), 조사 90분 후에는 28 kHz가 132 kHz보다 1.1배 높았다(28 kHz: 0.45 ppm, 132 kHz: 0.4 ppm). 2.5 ppm 나프탈렌 용액에 132 kHz와 28 kHz 초음파 조사시 발생된 H₂O₂ 농도는 초순수에 초음파 조사한 결과보다 각각 0.1 ppm과 0.05 ppm씩 낮게 나타났다. 혼형(24 kHz)과 배스형(28 kHz) 초음파의 나프탈렌 분해효율은 각각 87%와 82.7%였고, k1은 22.8×10(-3) min(-1)와 18.7×10(-3) min(-1)로 산출되었다. 다주파 복합형 초음파 시스템(28 kHz 배스형+24 kHz 혼형 초음파)의 나프탈렌 분해효율은 단일주파수 24 kHz(혼형)와 비슷한 제거효율을 보였으나(88%), H₂O₂의 농도는 약 3.5배 높게 조사되었다(28 kHz+24 kHz: 2.37 ppm, 24 kHz: 0.7 ppm). 이와 같은 다주파 복합형 초음파 시스템은 OH 라디칼에 의해 산화가 잘 일어나는 물질의 분해에 매우 효과적으로 적용될 수 있을 것으로 예상된다. Naphthalene is a volatile, hydrophobic, and possibly carcinogenic compound that is known to have a severe detrimental effect to aquatic ecosystem. Our research examined the effects of various operating conditions (temperature, pH, initial concentration, and frequency and type of ultrasound) on the sonochemical degradation of naphthalene and OH radical production. The MDL (Method detection limit) determined by LC/FLD (1200 series, Agilient) using C-18 reversed column is measured up to 0.01 ppm. Naphthalene vapor produced from ultrasound irradiation was detected under 0.05 ppm. Comparison of naphthalene sonodegradion efficiency tested under open and closed reactor cover fell within less than 1% of difference. Increasing the reaction temperature from 15℃ to 40℃ resulted in reduction of naphthalene degradation efficiency (15℃: 95%→40℃: 85%), and altering pH from 12 to 3 increased the effect (pH 12: 84%→pH 3: 95.6%). Pseudo first-order constants (k1) of sonodegradation of naphthalene decreased as initial concentration of naphthalene increased (2.5 ppm: 27.3×10(-3) min(-3)→10 ppm : 19.0×10(-3) min(-3)). Degradation efficiency of 2.5 ppm of naphthalene subjected to 28 kHz of ultrasonic irradiation was found to be 1.46 times as much as when exposed under 132 kHz (132 kHz: 56%, 28 kHz: 82.7%). Additionally, its k1 constant was increased by 2.3 times (132 kHz: 2.4×10(-3) min(-1), 28 kHz: 5.0×10(-3) min(-1)). H₂O₂ concentration measured 10 minutes after the exposure to 132 kHz of ultrasound, when compared with the measurement under frequency of 28 kHz, was 7.2 times as much. The concentration measured after 90 minutes, however, showed the difference of only 10%. (concentration of H₂O₂ under 28 kHz being 1.1 times greater than that under 132 kHz.) The H₂O₂ concentration resulting from 2.5 ppm naphthalene after 90 minutes of sonication at 24 kHz and 132 kHz were lower by 0.05 and 0.1 ppm, respectively, than the concentration measured from the irradiated M.Q. water (no naphthalene added.) Degradation efficiency of horn type (24 kHz) and bath type (28 kHz) ultrasound was found to be 87% and 82.7%, respectively, and k1 was calculated into 22.8×10(-3) min(-1) and 18.7×10(-3) min(-1), respectively. Using the multi- frequency and mixed type of ultrasound system (28 kHz bath type+24 kHz horn type) simultaneously resulted in combined efficiency of 88.1%, while H₂O₂ concentration increased 3.5 times (28 kHz+24 kHz: 2.37 ppm, 24 kHz: 0.7 ppm.) Therefore, the multi-frequency and mixed type of ultrasound system procedure might be most effectively used for removing the substances that are easily oxidized by the OH radical.
Lee, Sangsik,Oh, Seunghee,Yang, Aerin,Kim, Jihyo,Sö,ll, Dieter,Lee, Daeyoup,Park, Hee‐,Sung WILEY‐VCH Verlag 2013 Angewandte Chemie Vol.125 No.22
<P><I><B>Einen selektiven Phosphoserin‐Einbau</B></I> beschreiben H.‐S. Park et al. in ihrer Zuschrift S. 5883 ff. Eine allgemeine Strategie für den Aufbau rekombinanter Histone mit ortsspezifischer Serinphosphorylierung wurde entwickelt, die auf der Modifizierung einer Phosphoseryl‐tRNA‐Synthetase (SepRS) und des Elongationsfaktors Tu (EF‐Tu) beruht. Die Methode dürfte die Erforschung der Histonphosphorylierung und kreuzregulatorischer Mechanismen vereinfachen.</P>
{Poster Presentation} P46 : Angiotropic Metastatic Malignant Melanoma of Canine Mammary Gland Tumor
( Sun Hee Do ),( Won Ll Jeong ),( Sang Joon Park ),( Jae Yong Chung ),( Suk Hwan Lee ),( Young Ha Lee ),( Seo Jin Bak ),( Hee Joo Kim ),( Mi Na Seo ),( Mi Ran Ki ),( Won Seok Oh ),( Se Ll Park ),( Tae 한국수의병리학회 2005 한국수의병리학회 국제심포지움자료집 Vol.2005 No.-
콘크리트 구조물의 유지보수에 사용되는 누수보수재료의 인공 균열을 이용한 온도 안정성 시험평가
김수연(Soo-Youn Kim),김병일(Byoung-ll Kim),오상근(Sang-Keun Oh) 한국건설순환자원학회 2016 한국건설순환자원학회 논문집 Vol.4 No.3
본 연구에서는 콘크리트 구조물의 누수 균열 보수에 사용되는 재료에 대한 품질관리 방안으로 선행연구에 이어 후속 연구로 “온도 안정성 시험방법”을 제안하였다. 제안된 시험방법을 이용하여 5계열의 15 종류, 총 45개의 시험편을 대상으로 성능 평가한 결과 온도 안정성 시험에서는 저온(-20℃), 고온(60℃)의 다소 가혹 조건의 온도에서 얼었다 녹았다가 반복되면서 흘러내림, 체적변화, 색의 변화 등 다양한 재료 변화가 나타났고, 이에 대한 누수 여부 판별을 위하여 투수 시험한 결과 약 29%인 13개의 시료는 누수 되지 않았고, 약 71%인 32개 시료에서 누수되는 결과가 확인되었다. 결과는 현재 콘크리트 구조물의 유지보수에 사용되는 누수보수재료에 대한 온도 환경이 고려된 품질관리 기준 설정에 대한 필요성을 충분히 인식 할 수 있었으며, 콘크리트 구조물의 장기 내구성 확보를 위한 본 시험 방법인 “온도 안정성 시험방법”에 대한 표준적인 시험방법으로서의 활용 가능성을 확인하였다. This study is about the method to control the quality of material used to repair leakage and crack of concrete structure and suggests the “Temperature Stability Test Method” as a follow-up study. In the result of performance evaluation for 45 samples of 15 types in 5 series, the temperature stability test showed different material changes including rolling down, volume change, and color change as they are frozen and melt repeatedly in the somewhat extreme conditions at low(-20℃) and high(60℃) temperatures, where 13 samples (approx. 29%) and 32 samples (approx. 71%) showed leakage, respectively, in the permeability test to evaluate leakage. This result shows the enough importance of setting the quality control criteria of leakage repair material currently used to maintain concrete structures considering the temperature conditions, and proves the applicability of the Temperature Stability Test Method as a standard test method to ensure long-term durability of concrete structure.
A Routine System for Generation of Fertile Transgenic Rice Plants Using Biolistic Method
Lee, Soo-In,Shon, Young-Geol,Kim, Cha-Young,Lim, Chae-Oh,Choi, Young-Ju,Kim, Ho-ll,Lee, Sang-Yeol,Lee, Sung-Ho Plant molecular biology and biotechnology research 2003 Plant molecular biology and biotechnology research Vol.2003 No.-
A routine system based on particle bombardment of embryogenic callus for recovery of fertile transgenic rice (Oryza sativa L.) plants was developed. Embryogenic callus was established within 2-3 months from calli derived from mature seeds of Korean rice cultivar, Nagdongbyeo. The callus was bombarded with the plamid pRQ6 containing the β-glucuronidase gene (gusA) and hygromycin phosphotransferase gene (hph, conferring resistance to hygromycin B), both driven by CaMV 35S promoter. Placement of cells on an osmoticum-containing medium (0.2 M sorbitol and 0.2 M mannitol) 4 hrs prior to and 16 hrs after bombardment resulted in a statistically significant increase with 3.2-fold in transient expression frequency gusA. In five independent experiments, the average frequency of transformation showing GUS activities was 8.86%. A large number of morphologically normal, fertile transgenic rice plants were obtained. Integration of foreign gene into the genome of R_(0) transgenic plants was confirmed by Southern blot analysis. GUS and HPT were detected in R_(1) progeny and Mendelian segregation of these genes was observed in R_(1) progeny.