F.Mauriac와 연극

南宮 燃 카톨릭대학교 성심교정 1995 論文集 Vol.1 No.-

Mass Loss and Changes of Nutrients during Decomposition of Phragmites communis at the Fringe of Stream

Mun, Hueong-Tae,Namgung, Jeong,Namgung, Jeong-Hee-Namgung The Ecological Society of Korea 2000 Journal of Ecology and Environment Vol.23 No.2

Mass loss and changes of mineral nutrients during decomposition of Phragmites communis for 13 months from November 1998 to December 1999, were investigated at the fringe of stream at Boryeong, Chungnam Province in Korea. Plant materials, which were collected in November 1998. were divided into leaves, culms and rhizomes. Litterbags, 15${\times}$15 cm, were made of nylon mesh with 2-mm$^2$ holes. At 13 months after installation, remaining mass of leaves, culms and rhizomes was 29.0%, 57.4%, 20.6%, respectively. Mass loss rate of the culms was significantly lower than those of the leaves and rhizomes. The decay rate of leaves, culms and rhizomes was 1.21. 0.42 and 1.48 per year, respectively. Initial concentration of N, P, K, Ca and Mg of leaves. culms and rhizomes was 22.5, 9.0, 15.5 mg/g for N, 0.34. 0.10, 0.33 mg/g for P, 15.0, 12.5. 12.3 mg/g for K, 2.84. 0.80, 0.03 mg/g for Ca. 1.94. 0.97, 0.40 mg/g for Mg, respectively. Concentrations of nutrients were higher in leaves than in culms and rhizomes. Except for N and Mg in rhizomes, there was no immobilization period during the decomposition. In the case of remaining K and Ca, most are lost during the first 3 months. Without any suitable method for removal of dead part, eutrophication of freshwater may be accelerated by dead macrophytes.

Ecofriendly one-pot biosynthesis of indigo derivative dyes using CYP102G4 and PrnA halogenase

Namgung, Seyun,Park, Hyun A.,Kim, Joonwon,Lee, Pyung-Gang,Kim, Byung-Gee,Yang, Yung-Hun,Choi, Kwon-Young Elsevier 2019 Dyes and pigments Vol.162 No.-

<P><B>Abstract</B></P> <P>In this study, the biosynthesis of various indigoids with novel spectral features and antibacterial activities was investigated. First, 12 indole derivatives as substrates were biotransformed into functional indigoid dyes by <I>E. coli</I> cells expressing CYP102G4 hydroxylase. The indole derivatives included chloro (Cl-), nitro (NO<SUB>2</SUB>-), hydroxy (HO-), methoxy (CH<SUB>3</SUB>O-), methyl (CH<SUB>3</SUB>-), carboxy (COOH-), amino (NH<SUB>3</SUB>-), and cyano (CN-) indoles at the C4 to C7 positions. Interestingly, dramatic color shifts were observed from blue to red, green, purple, and even pink depending on the functional groups and their positions. Next, the biological and physical properties, antibacterial effects, and dying fastness of the prepared compounds were investigated and visually measured. Among the synthesized indigoid dyes, 6,6’-dichloroindigo and 5,5’-dichloroindigo showed the relatively higher cell growth inhibitory activity in the liquid phase. Finally, a one-pot producing strain which produced 7,7’-dichloroindigo from <SMALL>L</SMALL>-tryptophan using tryptophan-7-halogenase (PrnA) and CYP102G4 simultaneously was developed to overcome the disadvantages of uneconomical semi-synthesis through indole precursor feedstocks. The developed producing strain produced approximately 15.4 ± 1.4 mg/L of 7,7’-dichloroindigo in 24 h. To the best of our knowledge, this is the first report of the production of 7,7’-dichloroindigo in <I>E. coli</I> via a one-pot process.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Biological production of eco-friendly indigo derivatives. </LI> <LI> Biotransformation of indole derivatives using CYP102G4. </LI> <LI> One-pot biosynthesis of 7,7’-dichloroindigo by CYP102G4 and PrnA. </LI> <LI> 15.4 mg/L of 7,7’-dichloroindigo production in <I>E. coli</I>. </LI> <LI> Antibacterial activity of indigo derivatives. </LI> </UL> </P>

Dual bio-responsive gene delivery via reducible poly(amido amine) and survivin-inducible plasmid DNA

Namgung, Ran,Brumbach, Jonathan H.,Jeong, Ji Hoon,Yockman, James W.,Kim, Sung Wan,Lin, Chao,Zhong, Zhiyuan,Feijen, Jan,Engbersen, Johan F. J.,Kim, Won Jong Springer-Verlag 2010 Biotechnology letters Vol.32 No.6

<P>A bioreducible poly(amido amine) (SS-PAA) gene carrier, known as poly (amido-butanol) (pABOL), was used to transfect a variety of cancer and non-cancer cell lines. To obtain cancer-specific transgene expression for therapeutic efficiency in cancer treatment, we constructed survivin-inducible plasmid DNA expressing the soluble VEGF receptor, sFlt-1, downstream of the survivin promoter (pSUR-sFlt-1). Cancer-specific expression of sFlt-1 was observed in the mouse renal carcinoma (RENCA) cell line. pABOL enhanced the efficiency of gene delivery compared to traditional carriers used in the past. Thus, a dual bio-responsive gene delivery system was developed by using bioreducible p(ABOL) for enhanced intracellular gene delivery and survivin-inducible gene expression system (pSUR-sFlt-1 or pSUR-Luc reporter gene) that demonstrates increased gene expression in cancer that has advantages over current gene delivery systems.</P>

Cr(OH)₃(s) Oxidation Induced by Surface Catalyzed Mn(II) Oxidation

Namgung, Seonyi,Kwon, Man Jae,Qafoku, Nikolla P.,Lee, Giehyeon American Chemical Society 2014 Environmental science & technology Vol.48 No.18

<P>We examined the feasibility of Cr(OH)<SUB>3</SUB>(s) oxidation mediated by surface catalyzed Mn(II) oxidation under common groundwater pH conditions as a potential pathway of natural Cr(VI) contaminations. Dissolved Mn(II) (50 μM) was reacted with or without synthesized Cr(OH)<SUB>3</SUB>(s) (1.0 g/L) at pH 7.0–9.0 under oxic or anoxic conditions. Homogeneous Mn(II) oxidation by dissolved O<SUB>2</SUB> was not observed at pH ≤ 8.0 for 50 days. At pH 9.0, by contrast, dissolved Mn(II) was completely removed within 8 days and precipitated as hausmannite. When Cr(OH)<SUB>3</SUB>(s) was present, this solid was oxidized and released substantial amounts of Cr(VI) as dissolved Mn(II) was added into the suspension at pH ≥ 8.0 under oxic conditions. Production of Cr(VI) was attributed to Cr(OH)<SUB>3</SUB>(s) oxidation by a newly formed Mn oxide via Mn(II) oxidation catalyzed on Cr(OH)<SUB>3</SUB>(s) surface. XANES results indicated that this surface-catalyzed Mn(II) oxidation produced a mixed valence Mn(III/IV) solid phase. Our results suggest that toxic Cr(VI) can be naturally produced via Cr(OH)<SUB>3</SUB>(s) oxidation coupled with the oxidation of dissolved Mn(II). In addition, this study evokes the potential environmental hazard of sparingly soluble Cr(OH)<SUB>3</SUB>(s), which has been considered the most common and a stable remediation product of Cr(VI) contamination.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/esthag/2014/esthag.2014.48.issue-18/es503018u/production/images/medium/es-2014-03018u_0005.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/es503018u'>ACS Electronic Supporting Info</A></P>

Fluorescent Conjugated Polymer Containing Rhodamine Derivative for Förster Resonance Energy Transfer-Based Detection of Al³⁺ Ion

Namgung, Ho,Kim, Choongho,Kim, Yujun,Kim, Jongho,Lee, Taek Seung American Scientific Publishers 2016 Journal of Nanoscience and Nanotechnology Vol.16 No.8

<P>We report the synthesis of a fluorescent polymer containing the rhodamine 6G (Rh6G) derivative as a side chain. The rhodamine (Rh) moiety in the polymer had a ligand interaction with Al3+, which allowed the polymer to be used for detection of Al3+. The Rh moiety (in closed form) was non-fluorescent and colorless, whereas the open form of the Rh derivative showed strong fluorescence. Upon exposure to Al3+, the green-emitting polymer backbone had a spectral overlap with the absorption of the open form of Rh in the side chain, leading to an energy transfer from the polymer backbone to the Rh moiety. Upon addition of Al3+ to the polymer solution, the emission of the polymer backbone (green) has gradually decreased and, concomitantly, the red emission of Rh has increased via Forster resonance energy transfer (FRET). As the fluorescence of the polymer varied in the presence of Al3+ ions, the polymer could be used as a FRET-based sensor for detecting Al3+.</P>

Location-Awareness Management in IP-based IMT Network Platform ($IP^2$)

NamGung, Jung-Il,Shin, Soo-Young,Jung, Byeong-Hwa,Park, Hyun-Moon,Yun, Nam-Yeol,Park, Soo-Hyun Korea Multimedia Society 2010 멀티미디어학회논문지 Vol.13 No.6

$IP^2$, as an extended concept of the next generation IMT network, is a concept of basically supporting mobility using two steps of IP address (i.e. IPha (IP Host address) and IPra (IP routing address)) in IP backbone network. Current $IP^2$system has a shortcoming of excess usage of network resources caused by sending paging messages to all cells in LA (Location Area) in paging procedure. Considering the evolving direction of network, which is taking mobility with various speed and integration of devices into consideration, this shortcoming must be overcome. In this paper, we proposed a method to reduce time and memory for paging by maintaining current information of MN (Mobile Node) not in Active state with proxy server. Performance evaluation based on NS-2 simulations has shown that the efficiency of network resources is improved in the proposed method.

Weight Loss and Nutrient Dynamics during Leaf Litter Decomposition of Quercus variabilis and Pinus densiflora at Mt. Worak National Park

NamGung, Jeong,Han, A-Reum,Mun, Hyeong-Tae The Ecological Society of Korea 2008 Journal of Ecology and Environment Vol.31 No.4

Weight loss and nutrient dynamics of oak and pine leaf litter during decomposition were investigated from December 2005 through June 2008 at Mt. Worak National Park as a part of National Long-Term Ecological Research Program in Korea. The decay constant (k) of oak and pine leaf litter were 0.314 and 0.217, respectively. After 30 months decomposition, remaining weight of oak and pine leaf litter was 45.5% and 58.1%, respectively. Initial C/N ratio of oak and pine leaf litter was 53.4 and 153.0, respectively. Carbon % of initial oak and pine leaf litter was similar with each other; however, nitrogen content of initial oak leaf litter (0.85%) was greater than that of initial pine leaf litter (0.33%). N and P concentration in both decomposing leaf litter increased significantly during decomposition. There was no net N and P mineralization period in decomposing pine leaf litter. K, Ca and Mg concentration in both decomposing leaf litter showed different pattern with those of N and P. After 30 months decomposition, remaining nutrients in oak and pine leaf litter were 97.7 and 216.2% for N, 123.2 and 216.5% for P, 39.3 and 44.8% for K, 47.9 and 40.6% for Ca, 30.7 and 51.2% for Mg, respectively.

Path Space Approach for Planning 2D Shortest Path Based on Elliptic Workspace Geometry Mapping

Namgung, Ihn The Korean Society of Mechanical Engineers 2004 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.18 No.1

A new algorithm for planning a collision-free path based on algebraic curve is developed and the concept of collision-free Path Space (PS) is introduced. This paper presents a Geometry Mapping (GM) based on two straight curves in which the intermediate connection point is organized in elliptic locus ($\delta$, $\theta$). The GM produces two-dimensional PS that is used to create the shortest collision-free path. The elliptic locus of intermediate connection point has a special property in that the total distance between the focus points through a point on ellipse is the same regardless of the location of the intermediate connection point on the ellipse. Since the radial distance, a, represents the total length of the path, the collision-free path can be found as the GM proceeds from $\delta$=0 (the direct path) to $\delta$=$\delta$$\_$max/(the longest path) resulting in the minimum time search. The GM of elliptic workspace (EWS) requires calculation of interference in circumferential direction only. The procedure for GM includes categorization of obstacles to .educe necessary calculation. A GM based on rectangular workspace (RWS) using Cartesian coordinate is also considered to show yet another possible GM. The transformations of PS among Circular Workspace Geometry Mapping (CWS GM) , Elliptic Workspace Geometry Mapping (EWS GM) , and Rectangular Workspace Geometry Mapping (RWS GM), are also considered. The simulations for the EWS GM on various computer systems are carried out to measure performance of algorithm and the results are presented.

UNSTEADY FLOW ANALYSIS FOR THE DESIGN OF LOCAL SCOUR PROTECTION BY HEC-RASUNET MODEL IN THE RIVER REACH AFFECTED BY TIDE

NAMGUNG DON,CHO DOOCHAN,YOON KWANG SEOK 한국수자원학회 2005 한국수자원학회 학술대회 Vol.2005 No.1