• Analytical Science and Technology
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• v.24 no.3
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• pp.168-172
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• 2011

The iron frame of building could be collapsed or bent at $500^{\circ}C$. Therefore the fire-resistant paint should be applied for safety. This study performed the comparative analysis to show the characteristics of fireresistant paint. And then 12 products of fire resistant paint and 6 products of paints were used as samples. And the samples were analyzed by TGA (Thermogravimetric Analyzer) as analyzer for measuring the variation of weight on temper of weight by heating. When TGA analyzer could measure the variatiature, and FT-IR was measured for analyze gas components on variation on of weight by heating on 12 products of fire resistance, the samples showed to decrease 40% of weight to $800^{\circ}C$, and because paints had 50% to 40% of loss weight, it showed to be equal with loss weight of fire resistance paint on high temperature or was lower loss weight than it of fire resistance paints. However number 6 sample of fire resistance paints could show to decrease 20% of total weight on $800^{\circ}C$. And then in the case of FT-IR, fire resistance paints could show to have the high intensity of $CO_2$ spectrum as complete combustion. However paints could show to have the lower intensity of $CO_2$ spectrum, have the higher intensity of water spectrum. Therefore the TGA graph of result could be much different until $250^{\circ}C$. When it was burned, FT-IR spectrum could show to confirm the characteristics of fire resistance paints, and the characteristic could be confirmed on inorganic paint of fire resistance by weight loss of TGA.

• Journal of Korean Society for Atmospheric Environment
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• v.17 no.6
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• pp.475-485
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• 2001

The presence of airborne particles in the earth atmosphere expert important controls on the global climate because of their effects on the radiative balance. However, there are major uncertainties associated with the direct and indirect radiative effects of aerosols. In addition, their physicochemical properties cannot only the decline of air quality but also damage human health. Airborne particles were collected by two different commercial air samples, high volume sampler(for TSP) and low volume sampler(for P $M_{10}$ ) at the campus of Kunsan National University during February to September, 2000. In most cases, TSP and P $M_{10}$ were sampled once a week for the duration of 24 hours from 9:00 a.m. In addition samples were collected more intenisve, when the yellow dust was expected. Each sample was analyzed for pH and major ions concentration (C $l^{[-10]}$ , S $O_4$$^{2-}$, N $O_3$$^{[-10]}$ , N $a^{+}$, N $H_4$$^{+}$, $K^{+}$, $Mg^{2+}$, $Ca^{2+}$) by ion chromatography and atomic absorption spectrophotometry. Acidity (pH) of TSP and P $M_{10}$ ranged from 5.09 to 8.51 and from 6.22 to 7.54, respectively. The concentrations of airborne particles were found to satisfy both the short and long-term air quality standards during the sampling period. If the ratio of ionic concentrations originating from None sea salt(Nss) to sea salt(ss) in aerosol samples was concerned, it was found that the ionic concentrations from marine environment contributed dominantly in total mass concentration in the airborne particles. When seasonal trends were examined, the TSP concentrations in spring were higher than those of other seasons. It may result form frequent occurrences of yellow dust and during the spring season. The concentration ratio of P $M_{10}$ to TSP ranged from 0.78 to 1 during the sampling period. pH in the airborne particle was highest during spring, but the other seasons maintained almost same level. These results suggest that alkaline species in yellow dust can directly neutralize aerosol acidity. During spring season, yellow dust could be a positive factor that can defer the acidification of surface soil and water by neutralizing acidic aerosols in the atmosphere.osphere.

• Korean Journal Plant Pathology
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• v.1 no.3
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• pp.157-164
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• 1985

Some interactions in various soil conditions, numbers of microbial populations, root rot disease development and rates of spore germiation in three different location of soils were investigated. The calcium and magnesium contents were higher in replanted fields of ginseng (Panax ginseng) at Goesan. Potassium contents were high in replanted field at Poonggi and textural class of the soils was silt loam except for silt clay loam in first cultured field of ginseng at Goesan. For the germination process of Fusarium solani, F. moniliforme, F. oxysporum, and Alternaria panax, the percentage germination of fungal spores was high in double distilled water and Pfeffer's solution as media, whereas the lower rate of germination of spores was observed in soil extracts. Numbers of bacteria were high in replanted field soil at Gumsan, and propagules of fungi in replanted fields at Gumsan and Poonggi were higher than other soils, but higher numbers of actinomycetes were found in the first cultured field of ginseng at Goesan and Poonggi. Fungistasis was induced by higher microbial populations present in soil that was initiated when amended with garlic stalk, crushed bean and ginseng leaves. On the other hand, there was no fungistasis in soil amended with wheat and barley straw, and this tendency was a little difference on the soil sample.

• Journal of Life Science
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• v.24 no.4
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• pp.393-402
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• 2014

Culture-dependent and culture-independent denaturing gradient gel electrophoresis (DGGE) analyses were employed to investigate the bacterial community associated with a natural dye wastewater treatment facility. A total of 104 (influent water, 48 strains; aeration tank, 25; settling tank, 31) bacterial strains were isolated. Based on the 16S rRNA gene sequences comparison analysis, the isolates belonged to four phyla: Proteobacteria, Actinobacteria, Firmicutes, and Bacteriodetes. Seventeen DGGE bands representing dominant taxa in each sample were cloned and partially sequenced. The same four phyla were detected by DGGE fingerprinting. The most dominant taxon retrieved by both methods was the member of the phylum Proteobacteria with Alphaproteobacteria as the predominant class. The bacterial community associated with the natural dye wastewater treatment facility is composed of parasites of animals and plants, decomposers of polysaccharides and dyes, and producers of extracellular polysaccharides.

• Korean Journal of Food Science and Technology
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• v.13 no.2
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• pp.107-113
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• 1981

Free sugars were isolated from ginseng root and its products and analyzed by using high performance liquid chromatogrphy. To isolate free sugars from aqueous sample solution fat-soluble components, crude saponin and protein were removed from the solution by extracting with benzene, water-saturated butanol and 80% ethanol, respectively. Free sugars found from both ginseng root and its products were fructose, glucose, sucrose and maltose, and the only sugar detected from red ginseng root and its products was rhamnose. Major sugar detected from fresh ginseng and white ginseng roots was sucrose, while sucrose and maltose were major sugars of red ginseng root.

• The Korean Journal of Food And Nutrition
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• v.20 no.2
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• pp.150-157
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• 2007

Hamcho(Salicorinia herbacea, glasswort), a halophyte, is an annual succulent shrub that grows on coastal wetlands and has been regarded as a functional food for good health. Natural dried red and green Hamcho were extracted with 25% ethanol and water at 70$^{\circ}C$. The antioxidant activities of these four extracts were examined by six different assays, including the measurement of total phenolics, radical scavenging effects on 1,1-diphenyl-2-picrylhydrazyl(DPPH), nitric oxide(NO) and nitrite(NO$_2$) scavenging effects, reducing power, and the inhibitory effect on tyrosinase activity. The total phenolic contents of the four extracts were high at 237 ${\sim}$ 255 mg of gallic acid equivalents per 1 g of dried sample tested. The green Hamcho extracts contained more phenolic compounds than the red Hamcho extracts. When they were compared to tocopherols, the antioxidant activities of the green and red Hamcho powders were significantly higher at the same concentration levels(5 mg and 3 mg, respectively) in a POV test. The inhibition effects of the four extracts at a level of 75 ${\mu}l$ were higher than 98% in the POV test. The red Hamcho 25% ethanol extract showed a high significant effect on DPPH radical scavenging(SC$_{50}$, 90.1 ${\mu}l$). The green Hamcho 25% ethanol extract, however, showed a high significant effect on NO radical scavenging(SC$_{50}$, 6.1 ${\mu}l$). The NO$_2$ radical scavenging effect was assayed at pH 1.2, 4.2 and 6.0, and all the Hamcho extracts scavenged the NO$_2$ radical much more effectively at pH 1.2. The NO$_2$ scavenging effect of the red Hamcho 25% ethanol extract(64%) was as high as that of 5 mM vitamin C at pH 1.2(p<0.05). In the reducing power test, the red Hamcho 25% ethanol extract revealed the highest ferric ion reducing activity among the Hamcho extracts, and its activity was as high as that of 0.33 mg/ml of vitamin C. The four Hamcho extracts showed high tyrosinase inhibition effects of more than 80%, and their activities were higher than 50${\mu}$g of kojic acid. The green and red Hamcho 25% ethanol extracts totally inhibited tyrosinase activity(100%). Therefore, the results suggest that red Hamcho extracts may serve as useful natural antioxidants along with green Hamcho extracts.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.18 no.3
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• pp.122-130
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• 2013

To examine floc characteristics of cohesive bed sediment of the Yeongsan River estuary, a floc camera system has been developed and utilized to observe flocs under varying conditions. In order to validate the floc camera system, sand particles were passed through 88-125 and $63-88{\mu}m$ sieves and observed within the laboratory. Mean grain size and settling velocities were found to be 102 and $56.2{\mu}m$ and 6.7 and 5.9 mm/s, respectively. Artifacts of particles estimated outside of the sieve range are attributed to being imaged out of the depth of focus. However, as mean grain size and settling velocity of each size class were within the confidence interval, the floc camera system was confidently used to examine cohesive bed sediments of Yeongsan River estuary. The bed sediment sample was prepared with a concentration of 0.1 g/L in 0 psu deionized water. The mean grain size, settling velocity and fractal dimension of flocs were $40.6{\pm}0.66{\mu}m$, 14 mm/s, and 2.86, respectively. Experiments were also conducted using different salinities (10 and 34 psu) and sediment concentrations (0.1 and 0.3 g/L). Despite changing these parameters, the mean observed grain size and settling velocities were found to be the same within the error range of the system. The relatively higher values of settling velocity and fractal dimension are considered a result of the sediment containing relatively small concentrations of organic matter. Moreover, consistent floc size over various grain sizes and concentrations may be the result of insufficient turbulence to aggregate flocs.

• Korean Journal of Microbiology
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• v.40 no.4
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• pp.307-312
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• 2004

Diversity of the bacterial communities and the relation between community structure and components of waste­water were analyzed by 16S rRNA-based molecular techniques. Clone libraries of the 16S rDNAs from the sludges were constructed by PCR and cloning. The 1,151 clones from a sludge sample of sewage treatment plant were clustered into 699 RFLP phylotypes and the 1,228 clones from the wastewater disposal plant of chemical industry were clustered into 300 RFLP phylotypes. Shannon-Weiner diversity indices of two sampling sites were 8.7 and 6.1, indicating that the bacterial community structure of sewage treatment plant was more diverse than that of wastewater disposal plant of chemical industry. Forty clones belonging to predominant RFLP types were selected and sequenced. Seventy percent (28 clones) of the sequenced clones were related to the uncultured bacteria in public databases. The ${\beta}-Proteobacteria$ dominated in the bacterial communities of investigated two sludge samples. 16S rDNA sequences of the sewage treatment plant were similar to those of other activated sludges, while the bacterial community in wastewater disposal plant of chemical industry rep­resented the strains identified from high-temperature, anaerobic, hydrocarbon-rich, and sulfur-rich environ­ments. This result suggested that bacterial communities depended upon the components of wastewater.

• Korean Journal of Microbiology
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• v.51 no.1
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• pp.86-95
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• 2015

To study the halobacterial diversity at the rhizospheric soil of coastal plant native to Dokdo islands, several host plant were selected and its rhizospheric soil was sampled. Soil sample was diluted serially and pure isolation was done by sub-culture using marine agar media. 26 halophilic strains cultivable at the marine medium containig concentration of 9.0% sodium chloride were selected among total 161 isolates. Their partial 16S rRNA gene sequences extracted from genomic DNA were analyzed and partially identified. Furthermore, to identify their genetic relationship, phylogenetic tree was deduced. Total 26 strains were belongs to Firmicutes (30.8%), Gamma proteobacteria (53.8%), Bacteroidetes (7.7%), Alpha proteobacteria (7.7%), and Actinobacteria (7.7%). These results showed the specific difference from previous researches which has been reported the microbial flora of soil or sea water around the Dokdo islands. Furthermore, 4 among 26 halophilic strains grew at above 12.0% NaCl concentrated marine broth, and 2 strains Idiomarina abyssalis LM4H23 and Halomonas huangheensis AS4H13 grew at 15.0% concentration. These halophilic strains thought to overcoming the severe stress like high salt concentration or variation derived from Dokdo-specific climate and might have unknown, specific relationship with their host coastal plant native to Dokdo islands.

• Korean Journal of Materials Research
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• v.14 no.12
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• pp.893-899
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• 2004

Even though Ti-6Al-4V has gained popularity as an implant material, the possible dissolution of Al and V ions in body fluids remains a matter of concern. Though commercially pure Ti (Cp-Ti) overcomes this problem, the mechanical strength of pure titanium remains very low. Thus, in this experiment Cp-Ti was processed by Equal channel angular processing (ECAP), in order to increase the mechanical strength. The biocompatibility of ECAP-Ti, Cp-Ti and Ti-6Al-4V was examined by the apatite formation on each sample surface, after treating the surface with 5M NaOH and soaking in Simulated body fluids (SBF). Initially, the samples were mechanically polished on silicone carbide paper (#2000). The polished samples were treated with 5M NaOH solution at $60^{\circ}C$ for 24 hours. The NaOH treated samples were washed gently with distill water and dried at $40^{\circ}C$ for 1 day. The dried samples were heat treated in air at $600^{\circ}C$ for 1 hour. The surface morphology of these samples were studied using SEM and XRD. The SEM studies showed network of pores in all samples. The XRD showed oxide layer formation on Cp-Ti and Ti-6Al-4V. samples. However the oxide layer in ECAP-Ti was not substantial. These samples were immersed in SBF, kept at $36.5^{\circ}C$ for seven days period. At the end of 7 days, the apatite formation was confirmed only on Cp-Ti and was not observed in Ti-6Al-4V and ECAP-Ti. These observations of apatite formation relate to the fact that Cp-Ti showed greater oxide layer than other samples. The apatite examined was confirmed as tricalcium phosphate (TCP) using EDS and XRD.