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A New 1MV AMS Facility at KIGAM
Hong, Wan,Park, Jung Hun,Sung, Ki Suk,Woo, Hyung Joo,Kim, Jun Kon,Choi, Han Woo,Kim, Gi Dong Cambridge University Press 2010 RADIOCARBON Vol.52 No.2
<P>A 1MV AMS was installed in KIGAM (Korea Institute of Geoscience and Mineral Resources). After 4 months of installation, the AMS started normal operation from January 2008. This multi-element AMS was developed by HVEE to measure <SUP>14</SUP>C, <SUP>10</SUP>Be, and <SUP>26</SUP>Al. The results of an acceptance test demonstrate that this machine is capable of routine <SUP>14</SUP>C age dating and of measurements of other radioisotopes in terms of accuracy and precision as well as the background level. After installation, an investigation aimed at determining the stable operating conditions was conducted, and background levels were determined to be as low as 10<SUP>-15</SUP> for <SUP>14</SUP>C and 10<SUP>-14</SUP> for <SUP>10</SUP>Be and <SUP>26</SUP>Al.</P>
Hong, Yun-Gi,Moon, Yu-Mi,Hong, Ju-Won,No, So-Young,Choi, Tae-Rim,Jung, Hye-Rim,Yang, Soo-Yeon,Bhatia, Shashi Kant,Ahn, Jung-Oh,Park, Kyung-Moon,Yang, Yung-Hun Elsevier 2018 Enzyme and microbial technology Vol.118 No.-
<P><B>Abstract</B></P> <P>Glutaric acid is one of the promising C5 platform compounds in the biochemical industry. It can be produced chemically, through the ring-opening of butyrolactone followed by hydrolysis. Alternatively, glutaric acid can be produced via lysine degradation pathways by microorganisms. In microorganisms, the overexpression of enzymes involved in this pathway from <I>E. coli</I> and <I>C. glutamicum</I> has resulted in high accumulation of 5-aminovaleric acid. However, the conversion from 5-aminovaleric acid to glutaric acid has resulted in a relatively low conversion yield for unknown reasons. In this study, as a solution to improve the production of glutaric acid, we introduced <I>gabTD</I> genes from <I>B. subtilis</I> to <I>E. coli</I> for a whole cell biocatalytic approach. This approach enabled us to determine the effect of co-factors on reaction and to achieve a high conversion yield from 5-aminovaleric acid at the optimized reaction condition. Optimization of whole cell reaction by different plasmids, pH, temperature, substrate concentration, and cofactor concentration achieved full conversion with 100 mM of 5-aminovaleric acid to glutaric acid. Nicotinamide adenine dinucleotide phosphate (NAD(P)<SUP>+</SUP>) and α-ketoglutaric acid were found to be critical factors in the enhancement of conversion in selected conditions. Whole cell reaction with a higher concentration of substrates gave 141 mM of glutaric acid from 300 mM 5-aminovaleric acid, 150 mM α-ketoglutaric acid, and 60 mM NAD<SUP>+</SUP> at 30 °C, with a pH of 8.5 within 24 h (47.1% and 94.2% of conversion based on 5-aminovaleric acid and α-ketoglutaric acid, respectively). The whole cell biocatalyst was recycled 5 times with the addition of substrates; this enabled the accumulation of extra glutaric acid.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The first <I>E. coli</I> whole cell bioconversion from 5-aminovalerate to glutaric acid. </LI> <LI> Finding of critical factors for GabTD reaction. </LI> <LI> Achievement of high bioconversion rate over 90% based on α-ketoglutarate concentration. </LI> <LI> Repetitive use of whole cell biocatalyst to accumulate more glutaric acid. </LI> </UL> </P>
Hong, Yun-Gi,Kim, Hyun-Joong,Jeon, Jong-Min,Moon, Yu-Mi,Hong, Ju-Won,Joo, Jeong-Chan,Song, Bong-Keun,Park, Kyung-Mooon,Lee, Sang-Hyun,Yang, Yung-Hun Elsevier 2018 Journal of industrial and engineering chemistry Vol.64 No.-
<P><B>Abstract</B></P> <P>Efficient extraction and purification process is still a major bottleneck for economical production of cadaverine. We examined 10 different organic solvents to determine which one might be a suitable solvent for cadaverine extraction. Methyl ethyl ketone (MEK) was a very selective solvent for cadaverine. High pH was critical factor for cadaverine extraction with high purity. Cadaverine extraction efficiency of more than 70.1% with 99% of purity was successfully achieved by applying optimized extraction condition (pH 13.5, 58°C, 200rpm incubation for 6h). Cadaverine extraction using MEK seems quite feasible and promising for the preparation of polyamide monomers for environmental process.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Hong, Wan,Park, Jung Hun,Kim, Kyeong J,Woo, Hyung Joo,Kim, Jun Kon,Choi, Han Woo,Kim, Gi Dong Cambridge University Press 2010 RADIOCARBON Vol.52 No.3
<P>Many previous studies on the sample preparation of various kinds of radiocarbon dating samples by accelerator mass spectrometry (AMS) have been examined at KIGAM (Korea Institute of Geoscience and Mineral Resources) and our own procedures have been established. Furthermore, an automated reduction system has been developed. The volume of the reduction region was minimized to improve the reduction yield, and air-actuated pneumatic valves and solenoid arrays were used for computer control of the system. Operation of all the valves and vacuum pumps and signals from the temperature sensors and pressure gauges were interfaced to a personal computer with an A/D board. A computer program was also developed to perform automatic operation of the reduction system. This system consistently shows a higher reduction yield than 90%. The reduction time of the system is currently 140 min.</P>
침전법에 의한 알루미나 분말제조 Ⅲ. 소결체의 열적·기계적 특성
임헌진,이홍림,이형직,홍기곤 연세대학교 산업기술연구소 1992 논문집 Vol.24 No.1
A precipitation method was adopted in order to prepare high-tech Al₂O₃ceramics. Al₂(SO₄)₃·18H₂O was used as a starting materials and alumimum hydroxides were obtained by single precipitation method at the pH condition 7 and 11, using NH₄OH as a precipitation agent. Fine Al₂O₃powders were prepared at optimum calcination condition and were sintered at 1650℃ for 4 h in air. Microstructures and mechhanical properties of Al₂O₃ceramics were investigated. Doped MgO limited the grain growth of Al₂O₃and increased grain size homogeneity of Al₂O₃Flexural stregth values were 340∼430 MPa. Critical temperature difference?? was 175 K showing rapid strength degradation by thermal shock.
배일헌,한기석,차상훈,김성진,박길선,홍장수 충북대학교 의과대학 충북대학교 의학연구소 2003 忠北醫大學術誌 Vol.13 No.2
뇌혈관내 공기 색전증은 뇌혈관 조영술, 혈관내 도자술 시행시 발생하여 매우 심각한 합병증을 유발할 수 있다. 그러나 기흉의 합병증으로 발생한 경우는 보고된 적이 없다. 저자들은 기흉에 의하여 발생한 뇌혈관내 공기 색전증 1예를 경험하였기에 보고한다. Cerebral arterial air embolism is a potentially fatal event that may occur during the cerebral angiography and intravascular catheterization. The CT findings of cerebral arterial air embolism following pneumothorax have not been reported. We report a case of cerebral arterial air embolism following pneumothorax, and describe the CT findings.
배일헌,한기석,차상훈,김성진,박길선,이건국,홍장수 충북대학교 의과대학 충북대학교 의학연구소 2003 忠北醫大學術誌 Vol.13 No.2
선천성 낭성 선종양 기형은 태생 16주 이후 말단세기관지의 형성이 중단되어 미성숙기관지들과 중배엽성분들이 과도하게 증식하여 발생하는 드문 선천성 폐질환이다. CT소견은 낭종의 크기 숫자, 내용물 등에 따라 다양하나, 병변내에 정상적인 폐혈관이 보인 예는 전세계적으로 보고된 적이 없었다. 저자들은 역동적 흉부 CT상 균일한 저음영의 병변내에 정상 폐혈관상이 유지된 선천성 낭성 선종양 기형 1예를 경험하였기에 보고한다. Congenital cystic adenomatoid malformation(CCAM) is a rare pulmonary disease that is thought to be developed by abnormal proliferation of immature alveoli and other mesenchymal component from the abrupt halting of the terminal alveoli formation after 16 weeks of gestation. On CT scan, there are no consistencies regarding to size, numbers, and its contents but no cases were reported in past showing normal pulmonary vascularities. We reports a case of CCAM that showed normal pulmonary vascularities within the hypodense lesions on a dynamic chest CT