• Journal of Power System Engineering
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• v.5 no.2
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• pp.71-78
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• 2001

Using sodium hypophosphite as reducing agent, bath composition and plating condition of electroless copper plating on plating rate have been studied. The followings were determined as optimum, bath composition; $CuSO_4\;0.025M,\;NiSO_4\;0.002M,\;NaH_2PO_2\;0.4M$, sodium citrate 0.06M, $H_3BO_3$ 0.6M, thiourea or 2-MBT $0.2mg/{\ell}$, and operation conditions; pH $9{\sim}10$ at bath temperature rage of $60{\sim}70^{\circ}C$. A small amount of nickel ion($Ni^{2+}/Cu^{2+}$=0.002/0.025) to the hypophosphite reduced solution promotes autocatalysis and continuous plating. An additive such as thiourea or 2-MBT of a small amount($0.2mg/{\ell}$) can be used to stabilize the solution without changing plating rate much. The attivation energy between $20^{\circ}C\;and\;70^{\circ}C$ were calculated to be 11.3kcal/mol for deposition weight. Plating reaction had been ceased by the adjustment of pH above 13, temperature higher than $90^{\circ}C\;and\;under\;20^{\circ}C$. Deposited surface became worse in the case of increment of bath temperature above $80^{\circ}C$.

• The Korean Journal of Food And Nutrition
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• v.20 no.4
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• pp.363-368
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• 2007

Traditional kochujang samples were collected from the folk village in Sunchang to find the major microbial composition and correlation between the taste and the microbial properties. Among the 29 samples, 17 samples showed Bacillus licheniformis as dominant strain with 11 samples Bacillus subtilis and 1 sample Staphylococcus pasteuri. Subdominant strain of 17 samples was Bacillus licheniformis with 12 samples Bacillus subtilis. Dominant strain numbers varied in rage of $6.60{\sim}8.38$ logCFU/g with subdominant strain number $5.90{\sim}7.86$ logCFU/g and total microbial number $6.64{\sim}8.56$ logCFU/g respectively. Bacterial type number varied in range of $6{\sim}18$ with the average 10.5 types. Fungi were found only in 2 samples and identified all to be Aspergillus oryzae. Yeasts were found in 25 samples. The dominant yeast strain of 23 samples was identified to be Zygosaccharomyces pseudorouxii and that of 2 samples Zygosaccharomyces rouxii. Yeast type variety showed that only single type was found in 15 samples, 2 types in 8 samples, 3 types in 1 sample and 4 types in 1 sample. Fungal number was 3.90 and 4.08 logCFU/g and yeast numbers varied in range of $3.90{\sim}6.43$ logCFU/g. The sensory scores of kochujang showed positive correlation with type numbers, but no significant correlation with the other microbial properties like total bacterial number, dominant bacterial number, subdominant bacterial number and dominant yeast number.

• Spatial Information Research
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• v.10 no.2
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• pp.201-213
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• 2002

Chemical analyzes were carried out the samples from roadsides of the Gwangju city. The purpose of this research is to investigate the concentrations and distribution patterns of heavy metals due to urbanization and industrialization in the Gwangju city This study area is not significantly contaminated based on the concentrations of Cd, Cu, Fe, Mn, Pb and Zn. However, the concentrations of the chemical elements analyzed are locally higher than those of serious contamination level indicated by Ministry of environment. The dust pH is in the rage of 5.60-7.09 and was generally neutral, and there are no difference in pollution area and nonpollution area. Chemical analyses utilized are dilution by 0.1N HCl. In result of analysis by the method using 0.1N HCl, concentrations of Cd and Cu are a little high in Gwangchondong of Seo-Gu. Concentrations of Mn and Pb are a little high in Buk-Gu and Nam-gu, and Concentrations of Zn are generally higher than average of soils. Zn, in the study area, keeps polluting greatly as Zn concentration of average is 150.9ppm. All of P.I values are lower than 1, it means heavy metal pollution is not serious.

• Journal of the Korean Society of Clothing and Textiles
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• v.40 no.2
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• pp.203-220
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• 2016

This research analyzed characteristic changes in trading areas and the success factors of popular fashion trading areas (Garosu-gil, Dongdaemun, and Itaewon). This research adopts a social network analysis method to semantically analyze trading areas. Articles on the three fashion trading areas were located through KrKwic software to extract keywords and calculate word frequency. Keywords with high frequency were placed through NodeXL software to identify relationships among keywords. Researchers created a network of relationships among trading areas and between past and present of trading areas to analyze and visualize. In the past (2008-2009), the trading areas of Dongdaemun, Garosu-gil and Itaewon were placed horizontally with a limited number of shared keywords between them. However, the three trading areas retain diverse rage of keywords and an organic realtionships five years later (2013-2014). Compared to the past, all three areas see the emergence of relevant fashion keywords such as 'designer', 'design', 'brand'. Additional cultural keywords such as 'culture/art/performance', 'exhibition', and 'event' have commonly appeared and imply that related industries are an important factor as well. Fashion companies that consider evaluating areas for a new store opening need to understand the trading area characteristics and select the most suitable area. In addition, it is necessary to equip the trading area with basic fashion elements as well as relavant industry when the government tries to develop fashion trading areas.

• Journal of Energy Engineering
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• v.18 no.2
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• pp.141-146
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• 2009

In present work, we study the hydrogen storage of MWNT decorated with bimetallic Pt and Pd nanosize catalysts by Thermal Vapor Deposition [TVD]. The size of Pt and Pd particles is controlled as 5nm, 3nm, respectively by TVD. Before hydrogen storage measurement, the sample was heated for 1hr at $200^{\circ}C$ in H2 atmosphere. The Hydrogen sto rage of the sample was performed at room temperature and 33~34atm. The hydrogen storage of this composite showed 3.2wt% at 298K and 34atm, for three times. At 4th cycle, hydrogen storage is decreased to 1.5wt%, owing to the aggregation of bimetallic Pt and Pd nano particles.

• Journal of the Korean Ceramic Society
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• v.40 no.12
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• pp.1224-1228
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• 2003

The crystallization behavior of a luster glaze containing ceria has been investigated. When glazed specimens were sintered at 110$0^{\circ}C$, crystalline ceria particles were preferentially precipitated with (100) planes parallel to the specimen surface with the size of around 200 nm. The particle population in the surface region was much higher than inside glaze, covering over 60% of the specimen surface area. Crystallization of the particles with preferred orientation was promoted, after the removal of internal interface through complete melting of the fit particles. The luster effect seems to result from CeO$_2$ particles of high refractive index, their strong light scattering at visible rage due to fine crystalline size 200 nm and their planar arrangement in the surface region.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1992.11a
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• pp.77-81
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• 1992

The purpose of this research was th evaluate conductivity of electricity of Ge-Se-Bi system Chalcogenide glass as a amorphous semiconductor by observing its dissolution and crystallization. In this experiment. Ge-Se-Bi metal powder in the rage of $Ge_{12-25}$, $Se_{65-85}$, $Bi_{2.5-15}$ was used as the sample ore. The ore was. put into a vaccous quartz tube and then melted. The condition of heat treatment was to dispose it to $1000^{\circ}C$ heat for 10 hours and then rapidly quenched it at $3834^{\circ}C$/see. The crystallization of the fused sample ripened as the change of temperature and time, after the crystal core was formell. At that time it was possible to observe the state that $Bi_2Se_3$ and $GeSe_2$ were crystallized. In the experiment of making memberance, the memberance was produced by using the previously experimented bulk sample. And decrystalization was well progressed when Ge was over 15 at %, Se was over 70 at %, and Bi was under 10 at%. As for bulk. when Ge was fixed to 20 at %, the conducting of electricity was increased as Bi gained at %. In the case of memberance, the conductivity was much more increased than that of bulk sample as the increase of at the increase of at % of Bi. In the experiment on $Ge_{20}$, $Se_{77.5}$ and $Bi_{2.5}$, the crystallization sswas most vigorous when they were kept at $330^{\circ}C$ for 4 hours.

• Ocean and Polar Research
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• v.28 no.3
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• pp.317-329
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• 2006

To assess the contamination status of organochlorine pesticides in the marine environment of Saemangeum, surface seawater and sediments were collected and analyzed. Organochlorine pesticides were widely distributed in the Saemangeum environment, with DDT, HCH and endosulfan II contamination being particularly prevalent. The overall concentrations of DDTs, HCHs, and endosulfan II in surface seawater were in the rage of 0.03-0.65ng/l (mean value: 0.36ng/l), 1.31-4.54ng/l (2.63 ng/l), and not detected (ND)-0.96ng/l (0.49ng/l), respectively. Among the target organochlorine pesticides, endosulfan II showed the hi띤est level at the river mouth flowing into the Saemangeum. Additionally, its negative gradient from the rivers to the outside and a good correlation with $NO_3^-$ indicate that endosulfan ll inflows to the Saemangeum through the river; this conclusion is also supported by the elevated levels of endosulfan II in sediments at the river mouth. In sediment, the concentration of DDTs, HCHs, CHLs, and endosulfan II were in the range of 0.05-1.96 ng/g, 0.03-0.31ng/g, 0.01-0.13ng/g, and ND-0.62ng/g, respectively. Levels of contamination in Saemangeum are relatively lower than the median concentrations previously observed at the Korean coastal regions and sediment quality guidelines suggested by NOAA (Long et at. 1995).

• Analytical Science and Technology
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• v.25 no.1
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• pp.69-75
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• 2012

This study was performed to survey the school supplies such as pencil, eraser, notebook and color paper. Twenty-two kinds of samples were collected near the school zone, and eight kinds of phthalate which is one of the environmental hazard factors analyzed to estimate the contents characteristics of products. As the results of these research, three kinds of phthalates (BBP, DNOP and DIDP) were not detected in the selected samples. In the A group, DEHP and DINP were detected in the rage of 22%~28%, and DINP was selected 28%, 24% and 28% in the A-1, A-3 and A-4 samples, respectively. But the selected samples in the B group were detected less than 1,000 ppm as regulated level. Also, The DBP was detected 1% in the C-2 sample, and DEHP was detected 0.3% in the C-1 and C-6 samples. The DEHA was detected 0.3% in the D-3 sample. In this study, the DINP was mainly detected the eraser, therefore this kind of phthalate can be exposed through dermal exposure.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.16 no.2
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• pp.225-233
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• 1998

It is necessary to check the water quality of the lake on a continuous basis to determine the appearance of water pollution; however, it not only takes much time and expenses but it is considerably difficult to investigate the wide range of the area. If we use the remote sensing technique through the use of satellites, the status of water quality can be checked covering many wide areas simultaneously; and because the same area can be measured on a periodic basis, it is extremely effective in investigating the water quality. Furthermore, as some of the Landsat sensors carry characteristics which sense objects according to wave length, the distribution of water quality can be checked relatively accurately within a short period of time, while its image can be displayed in color. Hence, this research has attempted to extract water quality elements, such as transparency, water depth, and surface water temperature by utilizing the satellite data, and has prepared the water quality distribution image map of the Lake Hwajinpo by presenting the related empirical formula of the water quality elements. If the water quality distribution image map is prepared after extracting the water quality elements from the DN of the Landsat TM image and then carrying out TIN analysis through the use of GIS, relatively more accurate pattern can be learned covering a wide rage of area than the pattern presented based on the value obtained from actual observation.