• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.4 no.3
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• pp.217-226
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• 2006

The structural and contamination characteristics of hot cells at KAERI were investigated. The SEM results showed that the size of the hot particulate on the inner surface of the hot cell ranged from 0.2 to $10{\mu}m$. It was found that an inlet flow rate of 15 m/sec was suitable for this developed cyclone with a 49 mm optimum vortex finder length. The results showed that the collection efficiency was about 85% for $3{\mu}m$ particles. The collection efficiency didn't show a sharp increase when the inlet flow rate was faster than 15m/sec. When the temperature of the inlet flow gas was increased, the collection efficiency of the cyclone was slightly decreased. The larger the vortex finder length was, the higher the pressure drop in the cyclone was. The cut size diameter decreased with an increment of the Reynolds number. It was established that the flow in the cyclone was a turbulent flow on the basis of the Reynolds number and this turbulent flow caused a pressure drop in the cyclone. $Stk^{1/2}_{50}$ decreased with increasing values of the Reynolds number and it gradually approached a constant value at a higher value of the Reynolds number Namely, $Stk^{1/2}_{50}$ approached approximately 0.045 between 6000 and 8000 of the Reynolds number.

• Journal of Mushroom
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• v.9 no.2
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• pp.69-73
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• 2011

We have researched on methods which can reduce fruit-body malformations of king oyster mushroom(Pleurotus eryngii). We collected many pathogens from diseased fruit-body or malformated fruit-body and identified with chemicobiological test and microscope. The factors of fruit-body malformations and increment of contamination during the pin-heading induction time were researched with ventilation amounts in growing room. When the pathogens having high pathogenicity were inoculated in spawn running bottle and at pin-heading induction time, symptom appeared or not appeared in according to air ventilation amounts in growing room. During the pin-heading induction time, humidity degree in growing room have kept of high level and air ventilation amounts were so little that fruit-body malformations ratio was high. But, even though pathogens were inoculated at the surface of bottle factitiously, if air ventilation amounts were enough, fruit-body malformation ratio was low.

• Analytical Science and Technology
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• v.16 no.6
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• pp.483-487
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• 2003

Amitrole is well-known as a non-selective herbicide and it is able to cause contamination of driking water as well as pollution of ground water and surface water. However, it is difficult to extract from water because it has a high solubility for water whereas a low solubility for general organic solvents. This method is described for the determination of amitrole in water samples by GC/MS. After evaporation of 10 mL water sample by a vacuum evaporator, amitrole was derivatized with isobutyl chloroformate (iso-BCF) on room temperature for 15~20 min. As a result, the sensitivity for GCfMS was improved as N-isobutoxycarbonyl amitrole derivative was formed. The linearity of the calibration curve showed good as 0.997. The recoveries were obtained more than 94.9% and relative standard deviations were less than 2.8% at $1.0{\mu}g/L$, $10.0{\mu}g/L$ and $100.0{\mu}g/L$. The limit of detection showed $0.1{\mu}g/L$ with a signal-to-noise ratio (S/N) of 3.

• Food Science and Preservation
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• v.9 no.3
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• pp.315-320
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• 2002

In order to improve some problems such as contamination of undesirable mold, mycotoxin production and excessive drying on the surface of traditional meju. Control meju without koji and capsule type meju(CM) coated with soybean mixture containing 0.5%, 1% and 2%(w/w) R. oligosporus koji were dried at room temperature (10∼15$^{\circ}C$) for 3 days. Control meju I was fermented in outdoor for 27 days. Control meju IIand CMs were fermented in Korean yellow clay room at 25$^{\circ}C$ for 7 days under 80% relative humidity as first step, and then fermented in outdoor (average temp. 2.7$^{\circ}C$, December) for 20 days as second step. The moisture content of CMs were higher than that of control meju I to the range of 2.88∼7.55%(w/w). pH and titratable acidity in CMs were similar to control group. Amino type nitrogen content in CMs(800.80, 816.0, 901.60 mg%) were 2.2∼2.6 times higher than that in control meju I (347.2 mg%). Reducing sugar content in CMs(2.78∼3.13%) was similar to control meiu I (2.10%) and control meju H(2.31%). Lightness(L) value of control meju I was higher than that of control meju IIand CMs.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.3
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• pp.225-232
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• 1998

In order to monitor the degree of heavy metal distribution in upland cultivations in Korea, both the cultivated soils and crops were collected from the 854 and 140 sites, respectively. The contents of cadmium (Cd), copper(Cu), lead(Pb), and zinc(Zn) in each sample were measured by Inductively Coupled Plasma(ICP) technique after 1N-HCl extraction. The content of Arsenic(As) was also measured with the same technique after 1N-HCl extraction. The average contents of heavy metal in surface soils(0~15 cm depth) were $0.135mg\;kg^{-1}$ for Cd, $2.77mg\;kg^{-1}$ for Cu, $3.47mg\;kg^{-1}$ for Pb, $10.7mg\;kg^{-1}$ for Zn, and $0.57mg\;kg^{-1}$ for As. Heavy metal contents of soil were similar to those values measured for upland soils in 1989, lower than soils under plastic film house in 1996. However, these contents were lower than "Countermeasure values for soil contamination"(Cd: 4, Cu: 125, Pb: 300, and As: $15mg\;kg^{-1}$ in soil) describled in Soil Environmental Conservation Act in Korea(1996). The contents of heavy metal in fresh vegetable, and root and tuber crops ranged $0.005{\sim}0.019mg\;kg^{-1}$ for Cd, $0.20{\sim}1.03mg\;kg^{-1}$ for Cu, $0.042{\sim}0.104mg\;kg^{-1}$ for Pb, and $2.0{\sim}4.0mg\;kg^{-1}$ for Zn, respectively.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.4 no.2
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• pp.144-154
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• 1999

Masan Bay is highly polluted by the discharge of large quantities of effluents from the industrial complex and domestic sewage of Masan City, Southeast Korea. Surface sediments from 9 stations were used for geochemical and foraminiferal analyses in order to investigate foraminiferal response to sedimentary pollution in the Bay. The heavy metal concentrations in sediments are relatively higher than those in Kyeonggi Bay and Daesan area, west coastal region of Korea. Zn, Cd, Pb, and As are more concentrated than in world average shale, indicating that the municipal and industrial effluents cause sediment contamination. Responses of benthic foraminifera to the sedimentary pollution effect document a degree of pollution in Masan Bay. The species number and diversity in Masan Bay had lower values than those in Gadeog Channel. In Masan Bay, agglutinated foraminifera are abundant and calcareous foraminiferal tests were frequently pyritized. Eggerella advena and Trochammina pacifica dominated at levels of pollution and could be opportunistic species. These data will provide a baseline for future assessments of environmental quality in Masan Bay.

• Journal of Korean Society of Forest Science
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• v.100 no.2
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• pp.305-313
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• 2011

Fertilization is essential to seedling production in nursery culture, but excessive fertilization can contaminate surface and ground water around the nursery. The objective of this study was to find optimal fertilization practice of container seedling production for reducing soil and water contamination around the nursery without compromising seedling quality. This study was conducted to investigate growth performance, photosynthesis, chlorophyll fluorescence, and chlorophyll contents of Liriodendron tulipifera growing under three different fertilization treatments (Constant rate, Three-stage rate, and Exponential rate fertilization). Root collar diameter, height, and biomass of L. tulipifera were the highest at Constant treatment. Like growth performance, seedling quality index (SQI) were higher at Constant than at other treatments, but not significantly different among treatments. L. tulipifera showed good photosynthetic capacity at all treatments. Photochemical efficiency and chlorophyll contents were significantly lower at Exponential than at other treatments. Therefore, Exponential fertilization which is 50% fertilizer of other treatments would maximize seedling growth and minimize nutrient loss.

• Journal of Korean Ophthalmic Optics Society
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• v.10 no.4
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• pp.313-321
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• 2005

To know the pollution level concerning the microbes contamination condition in soft contact lenses, 2 experiments were operated with different methods. Firs experiment, we observed lenses surfaces through a scanning electronic microscope after pollution sort contact lenses with the suspensions of Staphylococcus aureus, Pseudomonas aeruginosa and Entrobacter aerogenes which can be major bacteria causing keratitis as wearing on soft contact lenses. As 1 hour after pollution with the soft contact lenses, we observed that many bacteria adhered to the lenses, and the pollution condition got worse with passing time increase(2, 4, 6, 12, and 24 hours, respectively). At 12 hours lapse of polluting soft contact lenses with P. aeruginosa, some bacteria adhered to the lenses. And as 24 hours lapsed after pollution soft lenses with E. aerogenes, bacteria adhered to them, and atypical substance was observed some of the surface of lenses. Second experiment, we observed the microbe pollution condition in soft contact lenses by let 21 people in twenties(men & women), who doesn't eye disorders, wear soft contact lenses during 4 hours. As the result, many kinds of bacterium and fungus were observed, and especially, the bacteria could be identified with their colors and the shapes of colony, so we found that single type, two types, and three types of bacteria adhered to their lenses.

• Economic and Environmental Geology
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• v.39 no.6 s.181
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• pp.689-697
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• 2006

Distribution and speciation of arsenic in water resources was investigated in the Ulsan mine area. In 62% of uoundwater samples from the mine area, total As concentrations exceeded 0.05 mg/l, the Korean Drinking Water Standard. As(V) was the major type in groundwater with minor As(III). Arsenic species appeared to be in transition stages following redox changes after exposure to the air through the monitoring wells. In areas around the mine, the mine and Cheongog spring appeared to be the sources of arsenic contamination of water resources. The spring showed 0.345 mg/1-As, as much as seven times of the Korean standard. Groundwater and stream samples showed As-concentrations greater than 0.05 mg/l in 30% and 33% samples, respectively, and 60 and 67% of samples exceeded 0.01 mg/l of WHO guideline, respectively. Again, As(V) was a dominant species, however, several samples had As(III) in appreciable levels. In one stream sample, organic species including DMA and AsB were detected in low levels, probably resulted from transformation or related biogeochemical processes.

• Journal of Conservation Science
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• v.38 no.3
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• pp.243-253
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• 2022

Using non-destructive analytical methods, we identified the material characteristics of two gold fabric artifacts excavated from the Cheongsong Sim clan (Bugeum Wonsam, Jikgeum Chima), including the artifact condition, fiber type, surface contamination, and metallic threads. We found that the artifacts were buried and had turned brown; thus, we were unable to determine their original color. The fiber type was determined to be silk from cocoons, based on scanning electron microscopy, Fourier transform infrared (FT-IR) analyses of Amide I, II, III, and IV peaks, and color reactions Further, the FT-IR and X-ray fluorescence (XRF) analyses identified the white and black stains as natural resin hydrolyzed substances, such as lipids and proteins, that occurred as microbial decomposition due to body decay. Finally, the XRF analyses identified the thin gold layer of the metallic yarn as gold (Au). According to the FT-IR data and the color reaction to the metallic yarn medium, the adhesive component of the medium was a product of-Amides I, II, III, and 3000 cm^-1 within Amides A and B (an animal type), respectively. Thus, the medium was identified as Hanji (Korean paper), which is made from domestically produced Broussonetia kazinoki fibers.