• Korean Journal of Soil Science and Fertilizer
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• v.38 no.5
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• pp.294-300
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• 2005

The effect of hairy vetch sod culture on reduction of soil loss and providing of nitrogen was investigated for the fields of Chinese cabbage in Hoenggye-Ri, Pyeongchang-Gun Gangwon-Do (780 m above sea level) from 2002 to 2003. Hairy vetch was sowed at just before planting, 15, 30 and 40 days after planting and right after harvest of Chinese cabbage. Hairy vetch was sod-cultivated with Chinese cabbage. The amount of sowing was $40kg\;10a^{-1}$. In this experiment, proper sowing times that had no influence on the yield of Chinese cabbage were 30 and 40 days after planting while other sowing times led to decrease the yield. In case of the former, there was 74% reduction effect of soil loss compared with no-hairy vetch because of covering the fields with hairy vetch right after harvest. Moreover, when the hairy vetch was put into the soil before planting of Chinese cabbage in the next year, it showed 61-79% substitution effect of standard application rate ($320kg\;ha^{-1}$, chemical fertilizer) for nitrogen fertilizer. It is suggested that using hairy vetch as cover crop would be useful in conservation of soil loss and reduction input of agricultural materials.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.5
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• pp.280-289
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• 2003

The purpose of this study was to establish a model for recommendable application level of nitrogen fertilizer based on soil testing for summer chinese cabbage in highland. A field experiment was carried out with various nitrogen application levels in sand loamy soil with and without poultry manure compost. The application level of N in poultry manure compost plot was found to be $291kg\;ha^{-1}$ for maximum yield of chinese cabbage, and it was 87% of the required N application level, $335kg\;ha^{-1}$, for maximum yield of chinese cabbage in nonmanure plot. In the treatment of poultry manure, approximately $174kg\;ha^{-1}$ of N was required to obtain the same yield of chinese cabbage as the maximum yield obtained in the treatments without poultry manure application. Therefore, with poultry manure application, N application level can be reduced by 40%. Using these results, a new equation for N recommendation for chinese cabbage in highland soil was proposed. With the average organic matter content of $33g\;kg^{-1}$ in highland field, the application levels of N for chinese cabbage were in the range of $215-129kg\;ha^{-1}$, which means that 32.8-59.7% of current application amount of N fertilizer can be reduced.

• Journal of Wetlands Research
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• v.12 no.1
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• pp.75-82
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• 2010

This study was performed to figure out what would be effective to improve water environment in a retention pond which was located in Incheon. Chemical coagulation, seawater flocculation and Fenton treatment were carried out to improve water and sediment quality for the retention pond. Experimental results showed that pH of 11 was optimum pH for seawater flocculation and the high removal rates in terms of SS and T-P can be obtained by seawater flocculation. To eliminate the pollutants from the sediments we applied Fenton oxidation process. We compared whether direct oxidizing the sediments would be more effective than oxidizing them after elution. By Fenton oxidation only, the COD removal rate was 0.55 grams per one $H_2O_2$ gram. Whereas the removed COD grams per one $H_2O_2$ gram were 0.69 by Fenton oxidation after elution. It showed that the oxidizing after elution was about 25% more effective than the oxidizing without elution. Both treatments could improve the water quality of a retention pond from a level 6(very bad) to a level 3(normal) of Lake Water Quality Standard.

• Journal of Veterinary Clinics
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• v.24 no.3
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• pp.295-299
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• 2007

The detrimental effects of gene transfection on embryo development and the molecular mechanism behind the differential expression of genes related to early embryo development were assessed in the production of transgenic cow embryos through somatic cell nuclear transfer (NT). Parthenogenetic, IVF, and transgenic NT embryos derived from ${\alpha}_1$-antitrypsin transfected ear fibroblast cells was produced. To investigate the molecular mechanism behind lower developmental competence of transgenic NT embryos, the differential mRNA expression of three genes ($IFN-{\tau}$, Oct4, Fgf4) in the 3 types of embryo (Parthenogenetic, IVF, transgenic NT) was examined. RNA was extracted from ten blastocysts derived from 3 types of embryos and reverse-transcripted for synthesis of the first cDNA. The quantification of 3 gene transcripts ($IFN-{\tau}$, Oct4, and Fgf4) was carried out in three replicate by quantitative real-time reverse transcriptase PCR. Expression level of $IFN-{\tau}$ mRNA was significantly higher in transgenic NT embryos than parthenogenetic and IVF embryos (P<0.05). However, expression level of Oct4 and Fgf4 of transgenic NT embryos was significantly lower than IVF embryos (P<0.05). Altered levels of these three mRNA transcripts may explain some of the embryonic/fetal/neonatal abnormalities observed in offspring from transgenic NT embryos.

• Journal of Veterinary Clinics
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• v.24 no.3
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• pp.315-319
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• 2007

Transgastric endoscopic cholecystectomy was successfully accomplished in a 1-year-old, 15 kg, female, mongrel dog. Single-working channel flexible gastric endoscope was used with the aid of one abdominal laparoscopic port. Gastrotomy was performed using endoscopic needle knife at the ventral antral region. Through the gastric incision endoscope was advanced and retroflexed for the visualization of gallbladder. For the better exposure of surgical field, gentle traction was applied at the fundus of the gallbladder using laparoscopic grasping forceps. Cystic duct and artery was ligated using endoclips. After transecting the duct and artery, gallbladder was dissected using endoscopic coagulating grasping forceps and needle knife. Resected gallbladder was retrieved through the mouth and gastric incision site was sutured using endoclips. There was no evidence of bile leakage or stomach leakage on postoperative day (POD) 3. On POD 16, gastric endoscopy and laparoscopy was performed. Gastric endoscopy revealed complete adhesion of incision site. The content of the peritoneum appeared healthy, with no sign of infection, bile staining, or organ injury. The omentum was adhered over resected gallbladder fossa and the serosal surface of gastrotomy site. This is the first report of NOTES cholecystectomy in the dog and provides new concept of cholecystectomy of the dog.

• Journal of Welding and Joining
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• v.29 no.6
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• pp.56-64
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• 2011

Friction stir spot welding between 5454 aluminum alloy sheets with the different thicknesses of 1.4 and 1.0 mm was performed. In the welding process, the tool for welding was rotated ranging from 500 to 2500, and plunged to the depth of 1.8 mm under a constant tool plunge speed of 100 mm/min. And then, the rotating tool was maintained at the plunge depth during the dwell time ranging from 0 to 7 sec. The pull-out speed of the rotating tool was 100 mm/min. The increase of tool rotation speed resulted in the change of the macrostructure of friction-stir-spot-welded zone, especially the geometry of welding interface. The results of the tensile shear test showed that the total displacement and toughness of the welds were increased with the increase of the tool rotation speed, although the maximum tensile shear load was decreased. However, the change in the dwell time at the plunge depth of the tool did not produce the remarkable variation in the macrostructure and mechanical properties of the welds. In all cases, the average hardness in friction-stir-spot-welded zone was higher than that of the base metal zone. By the friction stir spot welding technique, the welds with the excellent mechanical properties than the mechanically-clinched joints could be obtained.

• Journal of Korean Society on Water Environment
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• v.23 no.2
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• pp.201-205
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• 2007

This paper reports the amount of $^{222}Rn$ and $^{238}U$ in 18 sites of ground water and 30 sites of surface water. The instrument used to count $^{222}Rn$ activity was the liquid scintillation counter (LSC) which could resolute ${\alpha}$ and ${\beta}$ radiations. And $^{238}U$ was analyzed by the inductively coupled plasma (ICP). Radon and Uranium were not detected in raw and treated water which were sampled in a water treatment plant. However, radon ($^{222}Rn$) was high concentration in ground water from Jeon-la, Gang-won. So was uranium ($^{238}U$) in case of ground water from Gang-won, Choong-chung. Radon ($^{222}Rn$) activities were detected less than 15 pCi/L at 5 sampling points, 15~300 pCi/L at 7 sampling points, 300~4000 pCi/L at 6 sampling points. However, Radon ($^{222}Rn$) activities of all ground water samples were less than 4,000 pCi/L, which was bellow American Alternative Maximum Contamination Level (AMCL). Uranium ($^{238}U$) concentrations were less than $0.1{\mu}g/L$ at 5 sampling points, from $0.1{\mu}g/L$ to $20{\mu}g/L$ at 13 sampling points. Uranium was not detected in about 30% of the whole samples, but the concentration ranged from relatively low to high concentrations depending on the sampling point. The minimum detectable activity (MDA) of radon was 15 pCi/L. and the detection limit of uranium was $0.1{\mu}g/L$.

• Conservation Science in Museum
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• v.14
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• pp.37-60
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• 2013

Conservation and analysis of wall painting Goguryeo was performed to classify the unknown fragments. The conservation naked eye observation, optical microscopy, and infrared examination were carried out in order to figure out the structure, quality of constituting materials, and damages such as cracks, and discolored fragments of colored areas. Based on such investigation, conservation was proceeded. and it was completed with strengthening the weakened pigment layer of wall blocks. In addition tombs where the wall painting fragments were excavated were investigated by making comparison with gelatin dry plates and copies possessed by National Museum of Korea. According to the result, they were Kaemachong, Gosan-ri Tomb No.1 Gamsinchong, and Wonbong-ri Tomb. The components of colors with which Goguryeo wall painting fragments were painted and the mineral pigments of the wall layer were analyzed. Portable µ-XRF spectrometer and X-ray diffractometer were employed. It showed that lime (CaCO₃) used for the wall layer, and the brown color is hematite(Fe₂O₃) and cerusite (PbCO₃) and lead oxide(PbO) were identified. In the red color, cinnabar (HgS) were detected.

• The Korean Journal of Mycology
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• v.40 no.1
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• pp.49-53
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• 2012

Hot-water extracted natural media were made from raw materials for mycelial culture of Pleurotus eryngii. Poplar sawdust, wheat bran and rice bran were used as substrates for hot water extraction. The mixed substrates of poplar sawdust, wheat bran, and rice bran with 50 : 20 : 30 (v/v/v, PWR523) and 50 : 30 : 20 (v/v/v, PWR532) were optimal for mycelial growth of P. eryngii, respectively. The hot-water extracted natural media from PWR523 and PWR532 showed a rapid mycelial growth and spawn running compared to PDA. There was no significant difference in mushroom yield when the mycelium grown on the hot-water extracted natural media was used as the inoculum source for producing fruit body.

• The Korean Journal of Mycology
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• v.40 no.4
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• pp.235-243
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• 2012

We studied the effect of fermented Rhus verniciflua stem bark (FRVSB) extract (used in herbal med-icine by Koreans) on the microbial growth and enzyme activity of 12 soybean-fermenting microorganisms, including Bacillus spp., lactic acid bacteria, yeast, and other harmful bacteria. The ethanol and methanol extracts of FRVSB inhibited the growth of Bacillus subtilis, Bacillus licheniformis, Bacillus cereus, and Zygosaccharomyces rouxii, and in the disk diffusion assay, their inhibition zone diameters were 11.06-12.23, 12.32-18.38, 11.47-11.84, and 13.59-14.21 mm, respectively. The water extract did not show any inhibitory effect. In fact, the water extract addition enhanced the growth of B. subtilis and B. licheniformis by 1.3-4.5 fold and that of B. cereus by 1.2-1.4 fold. However, the water extract did not affect the growth of Lactobacillus plantarum, Lactobacillus mesenteroides, Saccharomyces cer-evisiae, and Escherichia coli. The addition of water extract increased the amylase and protease activity of B. subtilis and B. licheniformis.