• Bulletin of the Korean Chemical Society
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• v.28 no.6
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• pp.929-935
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• 2007

The objective of this study was to develop a rapid, simple, and qualitative acetylcholinesterase (AChE)- detection kit, based on a modification of the Ellman and ELISA methods, for the detection of organophosphorus (OP) and carbamate (CB) pesticide. The developed kits were used to screen a large number of agricultural samples (spiked and real) for OP and CB pesticide residues. AChE was extracted from the heads of honeybees (Apis mellifera L.) using Triton X-100, and was purified through 3 steps: diethylaminoethylcellulose chromatography (DEAE), affinity chromatography and membrane filtering, and Mono-Q column chromatography. Epoxy-activated Sepharose 6B affinity chromatography was used for large-scale purification. The presence of OP and CB pesticide residues in agricultural samples was assayed on the basis of AchE inhibition value. The presence (6 bands) or absence of some colored bands on the test line indicated a negative or positive result, respectively. The limits of detection for measured organophosphorus (OP) and carbamates (CB) pesticide residues in standard pesticide solutions and fortified samples were ranged from 0.50 to 2.50 ppm and 0.50 to 4.75 ppm, respectively.

• Korean Journal of Food Science and Technology
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• v.21 no.5
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• pp.606-612
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• 1989

A New lectin from baby clam, Tapes japonica, was isolated and purified through the following procedures; acetone powder, 0.15M NaCl extraction, ammonium sulfate fractionation, N-acetyl-D-galactosamine-agarose affinity column, and ion exchange Mono Q of FPLC. This lectin nonspecifically agglutinated human erythrocytes but didn't agglutinate mouse and rabbit erythrocytes. And the lectin neither stimulated human lymphocytes nor agglutinated Sarcoma 180 cells. On polyacrylamide gel electrophoresis, the lectin migrated as a major single band indicating homogeneous. A molecular weight was estimated to be about 131,000 daltons by Biogel P-300 and 125,000 daltons by SDS-PAGE without ${\beta}-mercaptoethanol$. This lectin is supposed to be a tetramer composed of heterogeneous subunits, about 30,000 and 33,000 daltons. Baby clam lectin was inhibited by EDTA and recovered agglutinating activity by $Ca^{++}\;and\;Mn^{++}$. This lectin is revealed as glycoprotein that contained about 4.2% neutral sugar.

• Carbon letters
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• v.9 no.3
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• pp.203-209
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• 2008

The objective of this work is to study the feasibility of the preparation of the activated carbon (AC) from coconut tree flowers using high temperature fluidized bed reactor (HTFBR). The activating agent used in this work is steam. The reactor was operated at various activation temperature (650, 700, 750, 800 and $850^{\circ}C$) and activation time (30, 60, 120 and 240 min) for the production of AC from coconut tree flowers. Effect of activation time and activation temperature on the quality of the AC preparation was observed. Prepared AC was characterized in-terms of iodine number, methylene blue number, methyl violet number, ethylene glycol mono ethyl ether (EGME) surface area and SEM photographs. The best quality of AC from coconut tree flowers (CFC) was obtained at an activation temperature and time of $850^{\circ}C$ and 1 hr restectively. The effectiveness of carbon prepared from coconut tree flowers in adsorbing crystal violet from aqueous solution has been studied as a function of agitation time, carbon dosage, and pH. The adsorption of crystal violet onto AC followed second order kinetic model. Adsorption data were modeled using both Langmuir and Freundlich classical adsorption isotherms. The adsorption capacity $q_m$ was 277.78 mg/g., equilibrium time was found to be 180 min. This adsorbent from coconut tree flowers was found to be effective for the removal of CV dye.

• Analytical Science and Technology
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• v.17 no.1
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• pp.37-44
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• 2004

An alcohol oxidase from Hansenula polymorpha was strongly induced when cells were grown with 0.5% methanol supplementation as the carbon source. The induced Hansenula polymorpha alcohol oxidase was purified to electrophoretic homogeneity by using DEAE-Sephacel and Mono Q column chromatographys. The enzyme oxidized mainly primary aliphatic alcohols and exhibited high substrate specificity towards ethanol and methanol. The activity of the enzyme optimally proceeded at pH 8.5 and $50^{\circ}C$. The midpoint of the temperature-stability curve for the enzyme was approximately $52^{\circ}C$ and the enzyme was not completely inactivated even at $65^{\circ}C$ temperature. The enzyme showed resistance toward detergents and highly stable over 7 weeks of storage condition. This Hansenula polymorpha alcohol oxidase may be useful for the enzymatic determination of alcohol and for the industrial production of alcohols and aldehydes.

• Journal of Sericultural and Entomological Science
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• v.44 no.2
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• pp.64-68
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• 2002

The antibacterial protein gene, nuecin was expressed in Sf9 cells using baculovirus expression vector system (BEVS). The antibactetial activity of mature nuecin against Pectobacterium carotovorum subsp. carotovorum, Ralstonia solanacearum and Pseudomonas tolaasii was significantly high, demonstrating that nuecin had a wider antibacterial spectrum on gram negative and positive bacteria. The result appears to be superior to other antibacterial peptide, attacin. The nuecin was purified by SP-sepharose and Mono Q HR ion-exchange chromatography, and then by Superdex 200 HR 10/30 column. The purified nuecin is quite stable at 80$\^{C}$ and 100$\^{C}$ for several hours of incubation and in a wide pH range (pH 2-12).

• Journal of Aquaculture
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• v.21 no.4
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• pp.285-293
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• 2008

Vitellogenin (Vg) is the precursor of vitellin (Vn), the major yolk protein of teleost fishes. In this study, Vg and Vn proteins of the Korean bullhead Pseudobagrus fulvidraco were isolated using gel-filtration chromatography (Sephadex-G 200 column) and anion-exchange chromatography (Mono Q HR 5/5 column), respectively. Purified Vn with an estimated molecular mass of 360 kDa by gel filtration chromatography was obtained from ovarian egg, and it was composited to one major subunit with an estimated molecular mass of 107 kDa by SDS-PAGE. In the result of western blotting, one major band was detected using antiserum against Vn (anti-Vn). These results suggested that Vn was composed of three subunits having the same molecular weight in Pseudobagrus fulvidraco. Vg was induced by estradiol-$17{\beta}$ ($E_2$) and purified from $E_2$ treated male serum. The molecular weight of whole Vg was estimated to be 450 kDa by gel filtration chromatography, and it is composed of three subunits with estimated molecular masses of 110 kDa, 125 kDa and 147 kDa as determined by SDS-PAGE. In the Ouchterlony's immunodiffusion test using anti-Vn and antiserum against female and male serum, purified Vg was detected in matured female and Ez treated male serum but not in untreated male. These results can be used in detecting estrogenic contamination of the aquatic environment.

• Journal of Korean Society of Forest Science
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• v.90 no.4
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• pp.548-557
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• 2001

This study was carried out to classify forest vegetation of Mt. Myeonsan with phytosociological analysis of ZM School and to explain community types with CCA ordination. The research sites were located in the northern part of Kyungsangpook-Do area and in the southern part of Kangwon-Do. The 73 plots were investigated in the study areas which were including 291 plant species. The forest vegetation was classified into Quercus mongolica community group, Juglans mandshurica community group, and Larix leptolepis plantation. Q. mongolica community group was divided into 9 communities such as Rhododendron schlippenbachii community, Symplocos paniculata community, Pinus densiflora community, Betula schmidtii community, Fraxinus rhynchophylla community, Populus davidiana community, Tilia amurensis community, Betula costata community and Betula davurica community. J. mandshurica community group was divided into 5 communities and 4 groups such as Acer mono community (subdivided into Quercus serrata group and typical group), Fraxinus mandshurica community, Ulmus laciniata community (subdivided into typical group and Ribes mandshuricum group), Malus baccata community and Carpinus laxiflora community. And it was entirely classified into 17 vegetation units. According to CCA, Q. mongolica community group showed high positive correlation to topography, altitude and slope degree, and J. mandshurica community group showed high positive correlation to bare rock. However, L. leptolepis community group was not significantly ordinated with the gradient of environmental factors. And in correlation of axes, important environmental variables were topography and altitude.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.6
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• pp.573-582
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• 2010

In this paper, X-band transceiver for high resolution wideband SAR systems is designed and fabricated. Also as a technique for enhancing the performance, error compensation algorithm is presented. The transceiver for SAR system is composed of transmitter, receiver, switch matrix and frequency generator. The receiver especially has 2 channel mono-pulse structure for ground moving target indication. The transceiver is able to provide the deramping signal for high resolution mode and select the receive bandwidth for receiving according to the operation mode. The transceiver had over 300 MHz bandwidth in X-band and 13.3 dBm output power which is appropriate to drive the T/R module. The receiver gain and noise figure was 39 dB and 3.96 dB respectively. The receive dynamic range was 30 dB and amplitude imbalance and phase imbalance of I/Q channel was ${\pm}$0.38 dBm and ${\pm}$3.47 degree respectively. The transceiver meets the required electrical performances through the individual tests. This paper shows the pulse error term depending on SAR performance was analyzed and range IRF was enhanced by applying the compensation technique.

• Journal of Korean Society of Forest Science
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• v.88 no.1
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• pp.18-30
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• 1999

This study was carried out to compare the characteristics of hydraulic architecture by measurement of leaf specific conductivity(LSC) in the twenty-one deciduous broad-leaved species. The LSC's of stems were higher than in branches except Acer mono, A. triflorum, Betula schmidtii, Fraxinus rhynchophylla and Zelkova serrata, and lowest in junction parts as compared with stems and branches. In diffuse-porous species, the LSC was much higher in B. plalyphylla var. iaponica, B. schmidtii, Cornus controversa, Tilia amurensis than those of other species and especially lowest in A. triflorum. In ring-porous species, the LSC was much higher in Maackia amurensis, Paulownia tomentasa, Quercus aliens, Q. serrata than those of other species and lowest in Ulmus davidiana var. japonica. The LSC's of 1-year-old terminal shoots of stem(the leader and adjacent laterals) in A. triflorum, C. controversa. F. mandshurica, Q. mongolica and Z. serrata ranged from 22 to $139{\mu}{\ell}/g$ in the leaders, and 11 to $73{\mu}{\ell}/g$ in the adjacent laterals. The LSC's of leaders were usually greater than the adjacent laterals because of the hydraulic dominance of the leader shoot.

• Journal of agriculture & life science
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• v.46 no.4
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• pp.21-30
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• 2012

The objective of this study was to comprehend inter-species association and factors affecting species composition by factor analysis and to classify forest types of natural forests in Dootasan. We examined the correlation (positive or negative) of the major species by correlation analysis, the selection of three factors affecting the species composition by factor analysis, cluster analysis on the basis of factor scores, and the evaluation of the results of forest type classification by ANOVA. The outputs of correlation analysis were closely associated with those of factor analysis. The first factor affecting species composition was found to be the decline phenomenon of Pinus densiflora during forest succession process. The second and third factors were growth environments in valley and slope, respectively. The cluster analysis was carried out based on three factors affecting the species composition. The results indicated that the study area was classified into four forest types as follows: Quercus mogolica-Acer mono-Fraxinus rhynchophylla community, Q. mongolica community, Q. mongolica-Tilia amunrensis community and Pinus densiflora community. The dominant species of each community in the four classified forest types were significantly different (p<0.05).