• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.1169-1178
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• 1998

This study was performed to purify fig pectinesterase(F-PE) and characterize its in situ activity. Three kinds of F-PE were partially separated by using ammonium sulfate fractionation, Q-Sepharose column, CM-cation exchanger column chromatography, and HPLC. One of those was anionic protein and the others were cationic proteins. All of them had approximate molecular weight of 27,000 and lost rapidly their activity during storage. Therefore alternative crude enzyme was prepared by suspending the freeze dried and milled fig powder in 0.1 M NaCl at pH 7.5. F-PE had the optimum pH of 8.5, the optimum temperature of $50^{\circ}C$ with activation energy of 7,671 cal $mol^{-1}K^{-1}$ and stability up to $55^{\circ}C$ with 10 minutes heating. Optimum activity was obtained in $0.2{\sim}0.4$ M NaCl with optimum solubility at above 0.8 M NaCl.

• Journal of the Korean Geosynthetics Society
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• v.9 no.3
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• pp.39-45
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• 2010

When the ground temperature drops below $0^{\circ}C$, wet soils expand due to the ice formation in their porous space. This results in frost heave which causes structural stability problems. Frost heave is attributed by several factors such as physical soil properties and heat transfer including pore water phase change. Due to the complex physical phenomena, reliable and verified multi-dimensional numerical models for frost heave problems are still in a research stage. This study presents an efficient and simple method of overcoming numerical problems associated with sudden jump of heat capacity due to the phase change from water to ice in the pore space. This paper proposes heat transfer equation and finite element method when the saturated soils or porous rocks are subjected to freezing. Numerical analyses using the proposed method agree well with the known closed form solution and the laboratory test results.

• Korean Journal of Food Science and Technology
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• v.20 no.2
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• pp.263-271
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• 1988

Fatty acid composition and electrophoretic patterns of protein of Korean soybeans were studied, The protein content showed an inverse relation with the lipid content, The content of lipid types of total lipid was in the order of neutral lipid, glycolipid and phospholipid, Cultivar 102-B had higher content of neutral lipid but lower content of phospholipid compared with others. The main component of neutral lipid was triglyceride followed by sterol. The main fatty acids of total lipid were linoleic, oleic and palmitic acids, which comprised over 85% of total fatty acids. The main fatty acid of neutral lipid, glycolipid and phospholipid were linoleic acid. The polyacrylamide gel electrophoretic pattern of protein showed seven bands. The cultivar 102-B had the highest content of IIS globulin. Sodium-dodecyl sulfate PAG electrophoresis demonstrated that all soybeans had similar composition of subunit.

• Journal of the Korean Geosynthetics Society
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• v.21 no.4
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• pp.31-40
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• 2022

Recently, the Arctic resource development project, where undeveloped energy resources (oil, natural gas, etc.) are deposited, is actively being promoted for the perspective of diversifying the construction market and developing future energy resources. However, the frozen ground always has problems such as sinking and frost-heaving due to extreme weather. Therefore, it is necessary to analyze the thermal characteristics of the frozen soil to secure the stability of the ground structure. In this study, a series of laboratory tests were performed to evaluated the thermal characteristics of frozen soil samples in the oil sand field in Alberta, Canada. In additon, it was compared with the results of domestic(Gangwond-do) sample performed under the same conditions. As a comparison results of the experiments, it was clarified that the different frozen water content and thermal conductivity characteristics by temperature after completion of freezing could affect the frozen soil behavior.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.5
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• pp.533-538
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• 1995

Ten specimens of the imported pufferfish, fugu flavidus ('Sarnchaebog'), from China were assayed for anatomical distribution of toxicity, Also, a toxic ovary of each specimen was excised, and transferred into Bio-gel P-2 column chromatography for purification of the toxins. The average toxicity of all specimens assayed was calculated to be $4.1\pm 0.5\;in\;liver,\;2.8\pm1.1\;intestine,\;0.8\pm0.5\;skin,\;2.3\pm1.5\;testis\;39.0\pm16.0\;ovary\;and\;7.0\pm2.0 MU/g$ bile, respectively; Ovary was weakly toxic, but others were non-toxic or weakly toxic. Moreover, instrumental analyses including thin layer chromatography(TLC) and electrophoresis disclosed tetrodotoxin (TTX) and anhydro tetrodotoxin (anh-TTX), respectively. The toxins of the ovary gave four peaks in high performance liquid chromatography (HPLC) whose retention times (14 and 24 min) were close to those of TTX and anh-TTX, respectively.

• Korean Journal of Environmental Agriculture
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• v.19 no.3
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• pp.201-205
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• 2000

Eleven runoff $plots(3{\times}15\;m)$ were built on a sloping field of a high plateau in Kangwon Province, Korea. The plots were treated with different tillage, residue covers and fertilizers, corn and potato were cultivated, and sediment discharge was measured from the plots for 3 years. Agricultural management practices were monitored around the plots to develop adequate best management practices. The least sediment occurred from the plots with no-till and 100% residue cover $(corn,\;0.1{\sim}2.2\;t/ha/year)$ and with contour tillage and vinyl sheet cover plots $(potato,\;0.1{\sim}0.2\;t/ha/year)$. The largest sediment was measured from the plots with up-and-down till and no cover ($11{\sim}33$ and $16{\sim}31\;t/ha/year$ from corn and potato plots, respectively). The type of organic and commercial fertilizers seemed not to affect sediment discharge. Sediment discharge from contour plots were largely dependent on the collapse of ridges due to the flush of water stored in furrows. The sediment discharge from contour corn and potato plots with no residue cover was $10{\sim}27$ and $16{\sim}24\;t/ha/year$, respectively. No-till with residue cover, vinyl cover for tuber crops, construction of furrow dam, frost heave research, furrow and ridge tillage with furrow dam after tuber crop harvest, limited stalk harvest of row crops, use of winter cover crops, and other common best management practices were recommended to minimize the sediment discharge from a high plateau sloping land culture.

• Journal of Ginseng Research
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• v.25 no.4
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• pp.150-155
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• 2001

This study examined effects of the active ingredients from ginseng on paraquat(PQ) toxitity. Mice were given PQ(25mg/kg, ip) and then they were given total saponins (TS; 5mg/kg, orally), protopanaxadiol (PD; 5mg/kg, orally) and protopanaxatriol(PT; 5mg/kg, orally) per day for periods of 1,3 & 7 days. We measured the activities of superoxide dismutase (SOD), electrophoretic isozyme band, catalase (CAT) were compared in the liver of mouse that dose with PQ and/or TS, PD and PT. The activities of SOD, CAT were generally higher in PQ+PD group than others groups. Especially the activity of SOD was the highest in PQ+PD group than others groups. SOD isozyme separated into three bands by electrophoresis. One band was located to near the anode side and two bands were cathode side. As the results of treated with KCN, we were confiremed that the Cu, Zn-SOD was located to near the anode side but the Mn-SOD were cathode side. Our results suggested that an antioxidant effect of ginseng saponins elevated a protection ability to an oxidative damage by direct action of SOD, CAT and reinforced the synthetic ability of endogenous antioxidant material in living organism. Particularly, PD was a effective antioxidant compared with others.

• The Korean Journal of Pesticide Science
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• v.10 no.1
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• pp.50-55
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• 2006

A field-resistant strain of the diamondback-moth(Plutella xylostella L.), collected from Chinese cabbage alpine farmland at Gangwon-do, Korea, was used for determination of the characteristics of resistance to chlorpyrifos using the activities of esterases and glutathione-S-transferase(GST), protein sequestration and AChE insenstivity. Although the activities of esterases extracted from resistant strain and susceptible strain were not significantly different, isozyme bands shown on the electrophoresis were different. GST activity from field resistant strain was 1.5-fold higher than that of susceptible. No differences were shown between resistant and susceptible ones in protein sequestration. The insensitivities of AChE to chlorpyrifos, however, extracted from susceptible strain was 460-fold higher than those of resistant. These results indicated that the insensitivity of AChE is the major factor for developing the resistance and activities of GST might be a minor factor.

• Korean journal of applied entomology
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• v.44 no.2
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• pp.109-114
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• 2005

This study was conducted to investigate the life cycle of Tipula latemarginata Alexander in Korea. The field surveys for the life cycle of the species were carried out at the two sites of Neaseong Stream area in Bongwha County from January 2001 to December 2002. Also many individuals of the species were reared in laboratory to investigate the life cycle. T latemarginata appeared to have three generations a year under the rearing conditions at room temperature. All the processes of life cycle of the species, when reared at room temperature from September 2001 to March 2002, were as follows: Eggs usually hatched between 4 and 10 days after oviposition. First instar larvae grew rapidly and molted to the second instar in 7-9 days. Second instar larvae spent 5-7 days for next molting and third instar period lasted approximately 8-12 days. Fourth instar larvae spent 6 weeks to 5 months for pupation. Especially the duration of fourth instar larval existence was greatly lengthened and served as the overwintering stage. The duration of pupal stage was 6-10 days. In the field, T. latemarginata also appeared to have three generations a year at the favorable habitats.

• Korean journal of applied entomology
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• v.36 no.4
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• pp.331-340
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• 1997

Hyalophora cecropia attacin-like antibacterial gene was isolated from Bombyx mori induced with nonpathogenic bacteria. It was expressed in Spodopfera frugiperda 9 (Sf9 cells using baculovirus expression vector system (BEVS), and examined its antibacterial activity. With a cDNA library constructed from fifthinstar B. mori injected with Escherichia coli(4 X IOhcellsllarva), differential screening was performed using naive and induced mRNA probes. BmInc6 clone was screened by partial nucleotide sequence and GenBank database analysis. A complete nucleotide sequence of Bmlnc6 cDNA was determined (GenBank, AF005384). Its insert size was 852 bp and had open reading frame that started translation at position 35 and stopped at 679. And its putative polyadenylational signal existed at 812 bp. The number of amino acid deduced from Bmlnc6 cDNA was 214 and hydropathy analysis showed that this peptide was hydrophilic. This peptide deduced by BmInc6 was named nuecin. When the nuecin gene was expressed in Sf9 cells using BEVS, about 950 bp of the transcripts was detected. In addition, SDS-PAGE analysis showed that the molecular weights of intracellular expressed protein and the mature protein secreted to culture media were approximately 23 and 20 kDa, respectively. The antibacterial activity of nuecin against E. coli and Bacillus subtilis was significantly high, demonstrating that nuecin had a wider antibacterial spectrum with gram negative and positive bacteria than attacin.