• Economic and Environmental Geology
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• v.35 no.4
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• pp.355-368
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• 2002

The multi-storied Daewonsa stone pagoda (Treasure No. 1112) in the Sancheong, Korea was studied on the basis of deterioration and geological safety diagnosis. The stone pagoda is composed mainly of granitic gneiss, partly fine-grained granitic gneiss, leucocratic gneiss, biotite granite and ceramics. Each rock of the pagoda is highly exfoliated and fractured along the edges. Some fractures in the main body and roof stones are treated by cement mortar. This pagoda is strongly covered with yellowish to reddish brown tarnish due to the amorphous precipitates of iron hydroxides. Dark grey crust by manganese hydroxides occur Partly, and some Part coated with white grey gypsum and calcite aggregates from the reaction of cement mortar and rain. As the main body, roof and upper part of the pagoda, the rocks are developed into the radial and linear cracks. Surface of this pagoda shows partly yellowish brown, blue and green patchs because of contamination by algae, lichen, moss and bracken. Besides, wall-rocks of the Daewonsa temple and rock aggregates in the Daewonsa valley are changed reddish brown color with the same as those of the pagoda color. It suggests that the rocks around the Daewonsa temple are highly in iron and manganese concentrations compared with the normal granitic gneiss which color change is natural phenomena owing to the oxidation reaction by rain or surface water with rocks. Therefore, for the attenuation of secondary contamination, whitening and reddishness, the possible conservation treatments are needed. Consisting rocks of the pagoda would be epoxy to reinforce the fracture systems for the structural stability on the basements.

• Food Science and Preservation
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• v.30 no.2
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• pp.311-320
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• 2023

Surfactin, one of the most powerful biosurfactants, can be widely applied in agriculture, food, and pharmaceutics. The purpose of the present study was to establish suitable indicators for a rapid detection method that can confirm the surfactin productivity of cheonggukjang. In the present study, changes in the total number of bacteria were quantified according to the fermentation time of chenggukjang. Furthermore, physicochemical factors, such as pH, color value, surface tension, refractive index, absorbance, and protein contents, were assessed in chenggukjang viscous substances, and a correlation analysis between the physicochemical factors and surfactin contents was performed. We found that the protein contents gradually increased up to 48 h (4.21±0.11 mg/mL) without a change in the surface tension. Furthermore, the refractive index, absorbance at 280 nm, and color value were significantly increased as the fermentation time increased; however, there were no statistically significant differences after 36 h of fermentation. Interestingly, this result exhibited a tendency similar to the surfactin content according to fermentation time. These findings suggest that surfactin can be used as a suitable quality indicator and may provide an experimental basis for the fermented food industry.

• Journal of the Korea Fashion and Costume Design Association
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• v.15 no.3
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• pp.85-97
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• 2013

The purpose of this study was to examine purchasing conditions and consumer complaint for outdoor sportswear items. The data used for a study were the complaint facts of 256 cases that were received at the Consumer Complaint Center of Gyeongnam YWCA during the period from July 2011 to April 2013. The statistical methods used to analyze data were Frequency Analysis and $x^2$-test by SPSS 14. The results of purchasing conditions analysis for outdoor sportswear items were as follows. According to outdoor sportswear items, purchasing place, purchasing price, and materials showed significant difference. The department store showed the highest ratio, but the ratio showed difference according to items. The price between over 100,000 won and under 200,000 won was most in case of T-shirts, padding, down jumper, aloha shirts, and pants. It showed as T-shirts and pants mixed spinning materials the most, jacket, padding, and down jumper used polyester the most, aloha shirts used cotton the most. The results of consumer complaint analysis for outdoor sportswear items were as follows. As a result of difference analysis for complaint occurrence place according to outdoor sportswear items, a laundry showed the highest ratio. As a result of difference analysis for the period used outdoor sportswear items until complaint occur, there was no significant difference. As a result of difference analysis for complaint type and contents according to outdoor sportswear items, the complaint types and contents were classified largely as change of color, change of shape, change of surface and touch, breakdown of subsidiary materials, and others.

• Transactions on Electrical and Electronic Materials
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• v.16 no.5
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• pp.268-273
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• 2015

While analyzing the specimens before and after the thermal shock test, we found that the power drop rate of the bare cell was 5.08%, while the power drop rate of the ribboned cell was 16.49%. In comparative terms, the efficiency was lower at the ribboned cell than at the bare cell. While analyzing through EL (Electroluminescence) shots and cross sections, we tried to decipher the exact cause of the power drop. Although mere color change of the cell was observed at the surface of the bare cell, no abnormality could be found inside the cell. On the surface of the ribboned cell, the short circuit of gridfinger extended from the front part of the front electrode of the ribboned cells. Therefore, cracks occurred on the surface of the cell. Cracks also appeared inside the cell. While analyzing the I-V curve, we determined an increase in the leakage current and an increase of resistances in series in the bare cell. In the ribboned cell, the resistances in parallel reduced remarkably. An increase of resistances in series could also be verified. Conclusively, we deduced that the power drop rate in the bare cell is a life span of the cell itself; aging is the cause of power drop rate in cells. In case of ribboned cell, the power drop rate was directly influenced by internal cracks and an intermetallic compound layer joining the ribbon at the front electrode.

• Korean Journal of Materials Research
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• v.16 no.11
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• pp.692-697
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• 2006

Deodorization of natural zeolites have been improved not only for polar but also for non-polar pollutants by sucessive ion exchanges of H and Ag ions starting from Korean natural zeolite with high adsorption capacity. The modified zeolites with $TiO_2$ coating on the surface revealed high deodorization and photocatalytic decomposition effects. Further modification was made with $10{\sim}20nm$ silica nano particles coating on the surface, the resulting composite particles of $SiO_2/TiO_2/modified$ natural zeolite revealed not only comparable deodorization but also better durability and resisatnce to color change compared to the $TiO_2$/modified natural zeolite without much compensation of photocatalytic decomposition effect, when the composite particles were exposed to the polypropylene non-woven fiber coated with organic binder. It is expected for the composite particle prepared here to be used as indoor building materials for indoor air quality control.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.1
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• pp.56-65
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• 2022

This paper aims at estimating self-cleaning performance of mortar coated with photocatalytic suspension under various conditions. Experimental variables included the concentration (1.5 % and 3.0 %) of photocatalytic suspension for coating mortar specimen, the presence of hydrophilic agent in photocatalytic suspension, and applying the primer on the surface of mortar. The color change of methylene blue solution increased and accordingly self-cleaning performance increased as photocatalytic concentration increased. The presence of hydrophilic agent in photocatalytic suspension slightly decreased the self-cleaning performance compared to the conventional photocatalytic suspension. Test results also showed that mortar specimen including primer and specimen not including primer did not show significantly different self-cleaning performance. In addition, cracks on the surface of mortar specimens decreased as the photocatalytic concentration increased. Therefore, increase in cracks on the surface of mortar at different photocatalytic concentration might adversely affect the self-cleaning performance of mortar specimens.

• Korean Journal of Remote Sensing
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• v.27 no.3
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• pp.235-258
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• 2011

The purpose of this study is to investigate climatological variations from the temporal and spatial surface particulate organic carbon (POC) estimates based on SeaWiFS spectral radiance, and to determine the physical mechanisms that affect the distribution of pac in the Gulf of Mexico. 7-year monthly mean values of surface pac concentration (Sept. 1997 - Dec. 2004) were estimated from Maximum Normalized Difference Carbon Index (MNDCI) algorithm using SeaWiFS data. Synchronous 7-year monthly mean values of remote sensing data (sea surface temperature (SST), sea surface wind (SSW), sea surface height anomaly (SSHA), precipitation rate (PR)) and recorded river discharge data were used to determine physical forcing factors. The spatial pattern of POC was related to one or more factors such as river runoff, wind-derived current, and stratification of the water column, the energetic Loop Current/Eddies, and buoyancy forcing. The observed seasonal change in the POC plume's response to wind speed in the western delta region resulted from seasonal changes in the upper ocean stratification. During late spring and summer, the low-density river water is heated rapidly at the surface by incoming solar radiation. This lowers the density of the fresh-water plume and increases the near-surface stratification of the water column. In the absence of significant wind forcing, the plume undergoes buoyant spreading and the sediment is maintained at the surface by the shallow pycnocline. However, when the wind speed increases substantially, wind-wave action increases vertical motion, reducing stratification, and the sediment were mixed downward rather than spreading laterally. Maximum particle concentrations over the outer shelf and the upper slope during lower runoff seasons were related to the Loop Current/eddies and buoyancy forcing. Inter-annual differences of POC concentration were related to ENSO cycles. During the El Nino events (1997-1998 and 2002-2004), the higher pac concentrations existed and were related to high runoffs in the eastern Gulf of Mexico, but the opposite conditions in the western Gulf of Mexico. During La Nina conditions (1999-2001), low Poe concentration was related to normal or low river discharge, and low PM/nutrient waters in the eastern Gulf of Mexico, but the opposite conditions in the western Gulf of Mexico.

• Journal of Conservation Science
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• v.25 no.4
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• pp.451-464
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• 2009

To do conservation for ceramics, sometimes it needs to clean the ceramics chemically to remove stains on the ceramics, which should be performed with caution. This study will provide quantitative data about the extraction characteristics of major elements from ceramics through the soaking test to evaluate the stability of ceramic cleaning agents. As soft textured pottery(fired at $700^{\circ}C$) had high absorption, it showed higher extraction characteristics in short soaking time. Especially the strong acid among chemical cleaning agents caused the expoliation and the color change on the surface of soft textured pottery. But these color change had no effect on the physical characteristics of soft textured pottery. The hard textured pottery(fired at $1,000^{\circ}C$) is relatively stable in the cleaning agent because it is ascertained the extraction of that was not enough and also it had little chromatic and physical change by strong acid. Porcelains(Celadon, Whiteware and Puncheong ware) was safer than the soft textured pottery due to their low extraction. But it should take precautions to clean the porcelains with lots of cracklewares such like Puncheong ware chemically in connection with the extraction characteristics and their cracklewares.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.1164-1167
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• 2003

Recently CRT is getting flatted, As change of CRT trend from normal type to Flat type, the material of Shadow Mask was also changed from AK(Aluminum Killed) to Invar(Fe-Ni alloy) materials Until now we have used just AK(Aluminum Killed) for normal type TV(not flat type), but main raw material of shadow mask component was changed. . However recently Invar(Fe-Ni alloy) materials, which has advantage of Low Thermal Expansion and High Strength, has been developed as well as applying in mass production as CRT's trend has become more flat and fine pitch. As main raw material of shadow mask component was changed, conditions of process were changed. One of them, the importance of pre-etching process (assistant process for developing & etching) is improved because there are so many particles in the pre-etching bath because of Ni compounds. Since the solubility of Ni in pre-etching solvent is very low related to Fe's, so the compounds of Ni happen to make particles.(the solubility of Fe is twenty times Ni's) that particles happen to make process troubles and NG productions so to clear the particles we had to established high cost filtering system, but it is useless. As time goes by the quantity of particles (Ni compounds) was increased because of the capability of filtering system was not enough, the particles was produced continuous in bath, and it make quality problems. Hence we tried to develop the new pre-etching solution to remove the particles (Ni compounds) and to cost down the filtering system's running cost. But in improving the solution we discovered the new pre-etching solution made the PR developing better. In former solution there were three kinds of chemistry (COOH)2 , H2O2 , H2S04 .first the function of (COOH)2 is drilling the surface of Invar, during this mechanism Ni compounds occurred. Second the function of H202 is removing the PR fringe (half UV exposure zone on PR(PVA)), Third the function of H2S04 is the catalysis of (COOH)2 In those, (COOH)2 was the main reason to make the Ni compounds. So to improve the solutions we had to change (COOH)2 to the other material. the chemistry we improved was a complex chemistry based on H2S04 . after using this chemistry the particles problem was disappeared and there was another advantage cut down the PR fringe. The New solution made the function of H202 better so the PR developing improved. To be direct the catalyst of the new solution helped the H202. anyway First thing after change the solution the quality of shadow Mask for flat color TV was improved & the yield also improved. But the more important thing is how to control the new solution. So we accepted the new concept which was the degree of freshness. The degree of freshness is based on non-reacted solution which was 100% ( the degree of freshness) and calculated the melted Ni quantity as time goes by. So we made the gauging liner plot. In conclusion, many companies tried to make fine pitched Shadow Mask ,generally to make quality jump up it needed a lot of cost & persons .in this case the shift of core material made it possible.

• Journal of Conservation Science
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• v.31 no.1
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• pp.1-11
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• 2015

Seated Amitabha Triad at Muwisa Temple (Treasure No. 1312) had been known as wooden Buddha statue, but a precise safety inspection revealed that the statue is terracotta Buddha statue made with clay. The clay layer of Amitabha Triad was conserved due to its severe damage. In this study, experiments were conducted to produce the most appropriate filler for the conservation treatment of the seated Amitabha Triad. Mixed clay samples with various ratios were produced and surface hardening state, crack, color change, and shrinkage of the samples during dry process were measured. Loess, fine sand powder, and cotton were used to produce the mixed clay for the filler with six different ratios and then 12 different concentration glues made with glutinous rice glue, Pachymeniopsis Elliptica glue, and animal glue were added as adhesives. Total 72 types of samples were prepared and comparative study was conducted. As a result, when the mixed clay contains 2.5% cotton compared to the weight per cent of loess and fine sand powder and also loess and fine sand in the mixed clay have a 15:1 ratio, the mixed clay had the lowest shrinkage. Animal glue is considered as an appropriate glue since it had small color change, low physical property change and shringkage. Therefore, mixed clay (loess:fine sand=15:1) mixed with 15ml animal glue is likely to be a suitable filler for conservation treatment of the seated amitabha triad at the Muwisa Temple.