• Corrosion Science and Technology
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• v.12 no.6
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• pp.295-303
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• 2013

Silane surface treatments have been developed as an alternative for toxic and carcinogenic chromate-based treatments for years. It is consistently observed that ultra-thin films offer excellent corrosion protection as well as paint adhesion to metals. The silane performance is comparable to, or in some cases better than, that of chromate layers. Based on the tetra-ethylorthosilicate(TEOS) and methlyl trieethoxysilane(MTES), inorganic sol was synthesized and formed hybrid networks with $SiO_2$ nano particle and polypropylene glycol(PPG) on Zn alloyed steel surface. According to SST results, addition of 10nm and 50nm $SiO_2$ nanoparticle in synthesized solution improved anti-corrosion property by its shear stress relaxation effect during curing process. Also, SST results were shown that anti-corrosive property was affected by the amounts of organic compounds.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.295-304
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• 2010

Performance of a landfill liner is evaluated based on leakage rate and mass flux. In this study, the recently utilized double composite liner system, which consists of a geomembrane (GM), a geosynthetic clay liner (GCL), a GM, and a compacted clay layer (61 or 91.5 cm) is compared with other popular composite liners including the single GCL system, the Subtitle D liner system, and the Wisconsin NR500 liner system. The leakage rate through circular and long defects in the GM of the landfill liners is analyzed using numerical models. For the mass flux criterion, the analyses of inorganic contaminant transport through defects in the GM component of liner systems and diffusion of organic compounds through intact landfill liners are conducted using three- and one-dimensional numerical models, respectively. Cadmium and toluene are used in the analyses as a typical inorganic and organic substance, respectively, which will be chemical species encountered during landfill operation. The comparison shows that the double composite liner systems are superior to the other liner systems according to the performance-based evaluation.

• Journal of Korean Society on Water Environment
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• v.31 no.5
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• pp.533-542
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• 2015

In order to investigate the effect of internal loading from sediment on algal blooming at Chusori area in Daechung Reservoir, the amount and contamination level of sediment and the release rate of total phosphorus were analyzed. The sedimentary layer was consisted with two layers, and the average depth of upper and lower ones were 0.35 and 1.44 m, respectively. The fraction of inorganic phosphorus in the sediment was higher than that of organic phosphorus, and the fractions of phosphorus which responsible for internal loading were very high as in the range of 72.7 and 80.2% of inorganic phosphorus. The C/N ratio of sediment taken with core sampler indicated the organic compounds are originated from settled algae from water body. The average release rate of total phosphorus from sediment was $6.74({\pm}0.50)mg/m^2/day$. These results indicated that the internal loading from sediment contributes the excessive algal growth at Churosi area, and the countermeasures to improve the quality of sediments are required to manage algal blooming in Daechung Reservoir.

• Microbiology and Biotechnology Letters
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• v.24 no.4
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• pp.507-511
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• 1996

Medium optimization for xylitol production from xylose by Candida parapsilosis ATCC 22019 mutant was performed. Effect of various nitrogen sources on xylitol production was investigatied. Of inorganic nitrogenous compounds, ammonium sulfate was effective for xylitol production and yeast extract was the most suitable orangic nitrogen nutrient for enhancement of xylitol production. Effect of inorganic salts such as KH$_{2}$PO$_{4}$ and MgSO$_{4}$-7H$_{2}$0 on xylitol production was also studied. Optimal medium was selected as xylose of 50 g/l, yeast extract of 5 g/l, (NH4$_{4}$)$_{2}$SO$_{4}$ of 5 g/l, KH$_{2}$PO$_{4}$ of 5 g/l, MgSO$_{4}$-7H$_{2}$O of 0.2 g/l. In a fermentor by using the optimal medium, a final xylitol concentration of 37 g/l could be obtained from 50 g/l of xylose with a xylitol yield of 74% and a xylitol productivity of 0.58 g/1-hr. At 300 g/l xylose, fermentation was also carried out and then a final xylitol concentration of 242 g/l was obtained at 272 hours. It was corresponding to xylitol yield of 80.7% and xylitol productivity of 0.58 g/1-hr.

• Journal of the Korean Wood Science and Technology
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• v.48 no.1
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• pp.86-94
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• 2020

This study serves as basic research for the development of a new wood-based building finishing material that improved the weakness of inorganic materials such as gypsum board and magnesium board widely used as interior finishing materials and brought out the strength of the wood. The results of evaluating the physical and mechanical properties and the environmental effect related to hazardous substance discharge having manufactured a wood-magnesium laminated composite are as follows. The thermal conductivity and thermal resistance of WML board was improved by about 28~109 percent over magnesium board due to the low thermal conductivity of wood. The adhesive strength of WML board showed a similar result to that of plywood as it exceeds 0.7N/㎟, the adhesive standard of wood veneer which is presented by KS F 3101. Bending strength and screw holding strength were more improved by manufacturing WML board than magnesium board. The WML board manufactured in this study satisfied the criteria for emissions of hazardous substances prescribed in the Indoor Air Quality Control Act, and confirmed the possibility of development as a new wood-based composite material that can replace existing inorganic materials.

• Macromolecular Research
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• v.17 no.11
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• pp.894-900
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• 2009

This study examined the charge carrier photogeneration and hole transport properties of blends of poly (9-vinylcarbazole) (PVK), $\pi$-conjugated polymer, with different weight proportions (0~29.4 wt%) of (PEA)$VOPO_4{\cdot}H_2O$ (PEA: phenethylammonium cation), a novel organic-inorganic hybrid material, using IR, UV-Vis, and energy dispersive spectroscopy (EDS), thermogravimetric analysis (TGA), steady state photocurrent (SSPC) measurement, and atomic force microscopy (AFM). The SSPC measurements showed that the photocurrent of PVK was reduced by approximately three orders of magnitude by the incorporation of a small amount (~12.5 wt%) of (PEA) $VOPO_4{\cdot}H_2O$, suggesting that hole transport occurred through the PVK carbazole groups, whereas a reverse trend was observed at high proportions (>12.5 wt%) of (PEA)$VOPO_4{\cdot}H_2O$, suggesting that transport occurred via (PEA)$VOPO_4{\cdot}H_2O$ molecules. The transition to a trap-controlled hopping mechanism was explained by the difference in ionization potential and electron affinity of the two compounds as well as the formation of charge percolation threshold pathways.

• Korean Journal of Materials Research
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• v.28 no.12
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• pp.748-757
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• 2018

Inorganic semiconductor compounds, e.g., CIGS and CZTS, are promising materials for thin film solar cells because of their high light absorption coefficient and stability. Research on thin film solar cells using this compound has made remarkable progress in the last two decades. Vacuum-based processes, e.g., co-evaporation and sputtering, are well established to obtain high-efficiency CIGS and/or CZTS thin film solar cells with over 20 % of power conversion. However, because the vacuum-based processes need high cost equipment, they pose technological barriers to producing low-cost and large area photovoltaic cells. Recently, non-vacuum based processes, for example the solution/nanoparticle precursor process, the electrodeposition method, or the polymer-capped precursors process, have been intensively studied to reduce capital expenditure. Lately, over 17 % of energy conversion efficiency has been reported by solution precursors methods in CIGS solar cells. This article reviews the status of non-vacuum techniques that are used to fabricate CIGS and CZTS thin films solar cells.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.24 no.3
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• pp.141-148
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• 2018

Photo-oxidation is one of the main causes of food deterioration of great variety of foods, such as dairy products, nuts, meat products, and wine. It causes a loss of both nutritional value and sensorial quality of products and may even leads to the formation of toxic compounds. Active packaging for food and beverages has been investigated and developed with embedding light absorbers or blocking materials into the plastics. In recent years, several novel light barrier materials have been proposed as an alternative option for different applications. This article reviews the up-to-date technology in light absorber and blocking material with special emphasis on chemical compound and mechanism. Inorganic, organic, hybrid organic-inorganic, and natural light absorbers were scoped. The challenges and future perspectives of light barrier materials are also discussed.

• Journal of the Korean Society of Costume
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• v.49
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• pp.49-63
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• 1999

This research utilized the Energy Dispersive X-ray Spectroscopy(EDS) and the Inductively Coupled Plasma Mass Spectrometry in the analysis of chemical elements present among the textiles exhumed from Kupori Hwasung-kun Kyunggi-do. The two research objectives were: first to examine the elements present and their percent presence in Kupori samples: second to investigate whether the elements are part of mordant substances which could have been used when dyeing the KUpori textiles in the past. To meet such research purposes standard silk fabric was dyed with Sophorajaponica using alum and iron mordants. For alum mordant unpurified general alum and potassium aluminum sulfate(AlK(SO4)2). iron sulfate(FeSO4·7H2O) were used, From the results of EDS and ICP-Mass analysis the following conclusions were drawn. 1 According to the EDS analysis 9 elements Ca, S, Al, Si, K, Fe, P, Mg and Na were detected. 2. ICP-Mass result of the mordant chemicas showed high amount of A, Al and k present in alum mordants and S and Fe present in iron mordants. 3. Comparison of the ICP-Mass results of the mordant chemicals and those of the standard dyed samples suggested that the amount presence of Al and Fe is a strong indication of the usage of alum and iron mordants respecticely in an unknown dyed textile. 4, In the washed Kupori textiles Fe showed a relatively higher rate of presence in the samples Therefore it can be conjectured that those Kupori textiles were dyed with iron mordant based on the result of the above number 3. 5. It is probable that the other elements detected from the Kupori samples were incorporated into the textiles as part of the soil debris produced from the degradation of the dead within the coffin or the earth debris. They can also be part of the inorganic compounds inherent in the silk textiles themselves before dyed. 6. Among the elements it is likely that Ca which showed a high degree of presence among the unwashed samples was part of the inorganic compound inferent in the silk textiles.

• Korean Journal of Food Science and Technology
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• v.17 no.6
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• pp.516-521
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• 1985

Changes in phosphorus compounds and phytic acid of mung bean, soybean, sesame and perilla were investigated during soaking in water, germination, incubation at $60^{\circ}C$ and autoclaving at $120^{\circ}C$. The results showed that total P in all the seeds was decreased slightly by soaking and incubation, but increased in mung bean, soybean during germination. Inorganic P was increased for all the seeds after soaking for 24 hrs, while its content in mung bean, soybean and sesame was significantly increased during germination. Phytic acid content in mung bean, soybean and sesame was significantly seduced by 92 %, 76 % and 78 %, respectively, after 5-6 days of germination. Soaking the seeds for 24 hrs resulted in the reduction of phytic acid by the range of 8-25 %. It was also found that incubation at $60^{\circ}C$ for 10 hrs or autoclaving at $120^{\circ}C$ for 4 hrs affected significantly for removal of phytic acid from the legume seeds.