• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.3
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• pp.238-242
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• 2003

Reclaimed tidal areas for rice cultivation are irrigated with salt mixed water when there is severe drought. Therefore, we identified the critical concentration of saline water for rice growth on a reclaimed saline soil in Korea. The experiment was conducted at the Kyehwado substation of the National Honam Agricultural Experiment Station (NHAES) during 2001-2002. Two experimental fields with 0.1-0.2% for low soil salinity and 0.3-0.4% for medium soil salinity levels were used. The experiment involved four levels of salt solution mixed with sea water (at 0.1, 0.3, 0.5, 0.7%) compared with a control using tap water in a split-plot design with three replicates. Saline solution was applied only two times at seedling stage (10 DAT and 25 DAT) for 5 days. Gyehwabyeo and dongjinbyeo, japonica rice varieties, were used in this experiment. Plant height and number of tillers sharply decreased in the 0.5% saline water in low soil salinity level and 0.1% in medium soil salinity level. For yield components, panicle number per unit area and percentage of ripened grain dramatically decreased in the 0.5% saline water in low soil salinity and 0.1% in medium soil salinity level. But 1,000-grain weight of brown rice decreased sharply in the 0.5% saline water in low soil salinity and 0.3% in medium soil salinity, indicating that this component was not much affected unlike other yield components. Milled rice yield decreased significantly with saline water level in both low and medium soil salinity. In the 0.7% low saline soil, the yield index was only 36% compared with the control. In medium soil salinity, even the control plot showed only 62% yield index compared with the control in the low soil salinity treatment. Results indicated that the critical concentration of saline water for rice growth in terms of economical income of rice production was 0.5% in low soil salinity and tap water in medium soil salinity.

• Journal of Embryo Transfer
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• v.15 no.3
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• pp.295-302
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• 2000

The objective of this study was to compare different superovulation treatments using PMSG or PG600$^{ }$ and to determine the optimal time of oocyte recovery after hCG administration. A total of 90 prepubertal Yorkshire x Landrace gilts crossed with Duroc, 6~7 months old and 100~120 kg of body weight, were used. PMSG (1,500 IU/head) or 5~7.5 ml of PG600$^{ }$(400 IU of PMSG and 200 IU of hCG) were administrated subcutaneously, and then 1,000 IU of hCG were administered intramuscularly at 72 hours after PMSG or PG600$^{ }$ injection. At carious time of 44, 46, 48 and 50 hours after hCG injection, superovulated gilts were slaughtered in a local abattoir. Ovaries together with oviducts were excised from the body immediately after slaughtered and transported to laboratory in 39$^{\circ}C$ saline. Ovaries were examined fur the number of corpus hemorrhagicum and unovulated follicles present in the surface of ovary. The unovulated follicles were categorized into small (1~3 mm in diameter) and large (4~8 mm) groups according to their diameter. Oocytes were recovered by flushing both oviducts with micropipette tip (1~100 $\mu$l) attached to a 10-ml disposable syringe. The number of CH on ovary and recovered oocytes at 46, 48 and 50 hr after hCG injection in PG600$^{ }$ treated groups were significantly higher than the other group. Group of phCG 50 hr among PMSG treated groups had a greater number of CH and recovered oocytes(P<0.05). The number of CH on ovary and recovered oocytes at 50 hr after hCG injection in 1$\frac{1}{2}$ vial(7.5 ml) of PG600$^{ }$ treated groups was significantly higher than 1 vial(5 ml) of PG600$^{ }$ treated group(P<0.05). In conclusions, considering a number of corpus hemorrhagicum and recovered oocytes after superovulation in gilts, effective time of oocyte recovery by treatment with PMSG and hCG was post-hCG 50 hr and with PG600$^{ }$ plus hCG was post-hCG 46, 48 and 50 hr. Also, admini-stration of 1$\frac{1}{2}$ vial(7.5 ml) of PG600$^{ }$ treated group had a great number of CH and recovered oocytes.covered oocytes.

• Journal of Food Hygiene and Safety
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• v.32 no.3
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• pp.228-233
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• 2017

The aim of the current study was to examine genotoxicological safety of purified bee venom (Apis mellifera L.) The bacterial reverse mutation in Salmonella typhimurium (TA100, TA1535, TA98, and TA1537) and Escherichia coli (WP2 uvrA) were evaluated with purified bee venom at concentrations of 0, 1.5, 5, 15, 50, 150, and $500{\mu}g/plate$. Purified bee venom was negative in Ames test with both in the presence and absence of rat liver microsomal enzyme. According to these results, we concluded that purified bee venom did not cause bacterial reverse mutation. The safety of the purified bee venom at practical doses needs to be further evaluated in in vivo genotoxicity assays.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.11 no.1
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• pp.55-60
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• 1993

Forest occupied a part of natural ecosystem carries out a role of purifying air, preserving water resource, prevention of the breeding and extermination, recreation areas and etc that preserve and for me one's living environment. In this study, the classification for management of this forest is performed with Landsat TM Image. The classes are decided needle-leaf trees, broad-leaf trees, farming land and grass land, and water. When the TM digital images are classified on computer, water is represented in 7∼13 D.N. of 4th band. But the others is appeared similar mostly specific values so that must be done image processing. When the images compounded 2ed band and 3ed band are processed with ratio of enhancement. Needle-leaf treas is represented in l18∼136 D.N. of 1st band, broad-leaf trees in 72∼91 D.N. of 3ed band, farm land and glass land in 96∼120 of 3ed band. Forest Information is classified with M.L.C, an image classification method. The errors of needle-leaf trees, broad-leaf trees, farm land and grass land, and water are appeared each －7.43, ＋1.89,＋7.58 and －2.04 as compared the digital image with investigation on the scene. Finally, these results are useful for classification of forest vegetation with Landsat TM Image.

• Korean Journal of Food Science and Technology
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• v.18 no.6
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• pp.413-420
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• 1986

This study was attemtped to improve the conventional processing method and to establish the basic data for evaluating the product suitabilities of dried loach. The semidressed raw material were salted in 15% NaCl solution for 15 minutes and dried to contain about 44% of water, and then heated about 10 minutes at $80^{\circ}C$ controlled by microwave (2,450 MHz). The moisture content of monolayer value for the product showed 5.34% and its water activity was 0.28. The optimum relative humidity for the storage was recognized to be from 32% to 44%. The average shelf life around the year of the Nylon-PVC-PE $(40\;{\mu})$ packed product in domestic circulation market was estimated as 207.4 days. In comparison with raw material, the contents of the major amino acids, glutamic acid, alanine and valine in the product were shown to be slightly increased, while the level of lysine, aspartic acid and methionine were slightly decreased. The contents of saturated fatty acids and oleic acid were shown to be slightly increased, while the other fatty acids tended to be slightly decreased.

• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.3
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• pp.218-226
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• 2016

Field observations were used to study the characteristics and influence of groundwater level fluctuations on vegetation development on the natural beach of a sandy barrier island, in the Nakdong River estuary. The spatial/temporal fluctuations of the groundwater level and the interactions with the external forces (weather, ocean wave and tide) were analyzed. The results indicated that when it rains the groundwater level rises. During summer, when precipitation intensity is greater than 20 mm/hour, it rose rapidly over 20 cm. Subsequently, it fell gradually during periods of no precipitation. Seasonal characteristics indicated that the groundwater level was high during the summer rainy season and tended to fall in the winter dry season. The time-averaged groundwater level, observed from the four observations over 3 years (2012-2014), was about 1.47 m, higher than mean sea level (M.S.L.). It was shown that the average annual groundwater level rises toward the land rather than showing intertidal patterns observation. Differences in the presence or absence of a coastal sand dunes affected the progress of vegetation. In other words, in environments of saltwater intrusion where the groundwater level varies, dependent on the distance from the shoreline and bottom slope, sand dunes can be provided to affect soil conditions and groundwater, so that vegetation can be grown reliably.

• Korean Journal of Animal Reproduction
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• v.17 no.2
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• pp.165-171
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• 1993

While ornithine decarboxylase (ODC) is considered a key enzyme in the biosynthesis of polyamines, difluoromethylornithine(DFMO) acts as an inhibitor of polyamine synthesis. Cycling crossbred gilts were randomly assigned to one of two (treatment and control) groups (6/group). An indwelling silicone catheter was surgically implanted in the jugular vein of each animal. DFMO was dissolved in saline(200 mg/ml) and adminstered by i. m. injection at a dose of 80 mg/kg/day. The control group received an equivalent volume saline injection. DFMO was injected 3 times daily(08:00. 16:00. 24:00h) from day 16 of estrous cycle to 21 or until estrus. Once daily blood samples (10ml) were taken from day 14 until two days after the last DFMO treatment. Window blood samples were collected every 15 min for 8 h (from 08:00 to 16:00h) starting on day 16 and continuing until day 21 from one gilt per day. Serum progesterone (P$_4$), estradiol (E$_2$), LH and FSH were measured. Typical concentration profiles for P$_4$ and E$_2$ were seen during the follicular phase regardless of DFMO treatment. Injection of DFMO suppressed the preovulatory LH concentration in the serum(p<0.01) while having no effect on FSH profile. The present results indicate that DFMO had an inhibitory effect on LH secretion in the pig, but did not affect PI, E2 or FSH release.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.8
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• pp.798-807
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• 2008

Due to economic impairment derived from metal corrosion of pumping station installed around coastal area, it was needed for related cause-effect to be investigated for understanding practical corrosion behavior and providing proper control. This research was thus carried out to determine whether the microbe can influence on metal corrosion along with its control in the laboratory. For this study, groundwater was sampled from the underground pump station(i.e. I Gas Station) where corrosion was observed. Microbial diversity on the samples were then obtained by 16S rDNA methods. From this, microbial populations showing corrosion behaviors against metals were reported as Leptothrix sp.(Iron oxidizing) and Desulfovibrio sp.(Sulfur reducing) Iron oxidizing bacteria were dominantly participating in the corrosion of iron, while sulfate reducing bacteria were more preferably producing precipitate of iron. In case of galvanized steel and stainless steel, iron oxidizing bacteria not only enhanced the corrosion, but also generated its scale of precipitate. Sulfate reducing bacteria had zinc steel corroded greater extent than that of iron oxidizing bacteria. In the inactivation test, chlorine or UV exposure could efficiently control bacterial growth. However as the inactivation intensity being increased beyond a threshold level, corrosion rate was unlikely escalated due to augmented chemical effect. It is decided that microbial corrosion could be differently taken place depending upon type of microbes or materials, although they were highly correlated. It could be efficiently retarded by given disinfection practices.

• Journal of Navigation and Port Research
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• v.32 no.8
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• pp.637-643
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• 2008

When planning outfall system, the first target cif design is to maximize initial dilution of discharge effluent. To achieve the target effectively, the characteristics of mixing phenomenon between ambient and discharged water should be analyzed. Especially the analysis at the Near-Field-Region(NFR) as initial dilution zone should be preceded. Usually, the initial behavior of effluent through outfall system is rising toward the surface due to mixing with ambient water for heat discharge and sinking toward the bottom due to the difference of density for brine discharge. After mixed with eddies accompanied by the ambient water, the plumes are showing the same density and internal current pattern by advection and diffusion. Until recently, lots of studies are being carried out for the optimum design of outfall system. but it is difficult to find any studies of heat and brine discharge at the same time. Therefore, this study is hoped to provide some basic data for optimum design of outfall system.

• Korean Journal of Environment and Ecology
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• v.22 no.3
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• pp.241-248
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• 2008

We studied concentrations of trace elements such as iron, zinc, copper, lead and cadmium in three shorebird species from Saemankeum mudflat, Korea$(1999{\sim}2000)$, and also analysed correlations between elements in livers. Iron(ANOVA, p=0.018), copper(ANOVA, p=0.043), lead(ANOVA, p=<0.001) and cadmium (ANOVA, p=0.016) concentrations significantly differed among shorebird species, but zinc concentrations wasn't different among species. We suggested that iron, zinc, and copper concentrations were within a range for normal and are maintained by normal homeostatic mechanisms for wild birds. Lead concentrations in Great Knots Calidris tenuirostris$(5.76{\pm}2.14{\mu}g/dry\;g)$ were at the background level but Red-necked Stints Calidris ruficollis$(29.4{\pm}10.6{\mu}g/dry\;g)$ and Terek Sandpipers Xenus sinereus$(15.9{\pm}11.9{\mu}g/dry\;g)$ were within the exposed level for wild birds. In particular, Red-necked Stints were nearly poisoned level. Cadmium concentrations in Terek Sandpipers and Great Knots were at the background concentration, but Red-necked Stints were greater than the poisoned level$(3{\mu}g/dry\;g)$. We found significantly correlations between lead and cadmium concentrations, but other elements didn't find.