• Economic and Environmental Geology
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• v.39 no.3 s.178
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• pp.285-299
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• 2006

The Mireuksaji stone pagoda in Iksan is the largest stone pagoda existing in Eastern Asia. It was assumed that originally it had been established in the shape of nine-storied pagoda but as time went by only six-storied pagoda remained partially due to collapsing, repair and reconstruction. According to the reference, we can't make sure when its modification happened. The form that the pagoda is having now, was modified with concrete by the Japanese during the 1910s. The materials mixed in concrete were mixture of Portland cement, all sorts of stone, sand, and a little bit of new building stone, additive and compound. And also these materials were applied to cultural assets without any experiment at the time of 1910s as maintenance, which are still used recently. To prevent the change of its shape, the west side, south side and the north side which is partially destructed was rebuilt and reinforced with concrete and some of the deformed parts were also filled. The amounts of concrete used were about 200 tons. Such method had prevented the pagoda from destructing, however, by choosing a wrong repair method, its surface of the stone has secondary contaminants and precipitation caused by concrete. This kind of contamination speeds up the weathering which accelerates the aging mechanism of the stone to make it even harder to revive the absence of historical nature. Therefore, we are to find the best cleaning method to remove the secondary hazard contaminants.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.5 no.2
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• pp.89-100
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• 2019

In our previous studies, we developed a ¹⁸F-labeled TSPO-binding ligand, named [¹⁸F]CB251, which has been proved to be a promising TSPO-binding PET radiotracer for the detection and monitoring of TSPO expression in pathological diseases. (Ki = 0.27 nM for TSPO, 1.96% ID/g of tumor uptake at 1h post-injection) Based on these results, we utilized 6,8-dichloro-2-phenylimidazo[1,2-a]pyridineacetamide analogs, CB185 (1) as a targeting moiety for the selective delivery of probes and anticancer molecules to TSPO-overexpressed tissues. In this study, we designed CB185 derivatives contains different PEG chains (n = 1, 3 and 5) and fluorescence dye (Cy5) to identify the necessary space between a TSPO-binding ligand and an anticancer agent. Three CB185 derivatives (11a-c) which contains Cy5 and PEG chain, were synthesized and the effect of PEG additive on their TSPO-binding affinities were evaluated using in vitro assays. The binding affinity for compounds 11a-c was lower than that of PK11195 (Ki = 3.2 nM), but still characterized by nanomolar binding affinity for TSPO (Ki = 46.5 nM for 11a, 51.0 nM for 11b, and 388.5 nM for 11c). These results showed that the conjugates are characterized by a moderate binding affinity toward TSPO except for compound 11c, which PEG chain consist of five PEG monomers. Our finding might add useful information to decide the appropriate PET chain length for developing new TSPO-targeting drug carriers.

• Korean Journal of Microbiology
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• v.40 no.2
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• pp.154-159
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• 2004

Bacillus species were isolated from swine manure to develope the microbial additive suitable for the rapid com-posting. The 3 of 4 isolated strains were identified as Bacillus cereus KD-2, B. pumilus KD-3, and B. licheni-formis KD-4. Bacillus sp. KD-1 was, however, not highly identical with any Bacillus sp. The isolated strains were analyzed their growth rates, enzyme activities, and antibacterial activities. The maximum growth tem-peratures of KD-1, KD-2, KD-3 and KD-4 were $45^{\circ}C$, $50^{\circ}C$, $53^{\circ}C$, and $55^{\circ}C$, respectively. The activities of pro-tease or amylase in mixed culture of 4 strains were similar in the range of $37^{\circ}C$ to $53^{\circ}C$ and activities of lipase in the range of $37^{\circ}C$ to $42^{\circ}C$ were twice higher than those of lipase in the range of $47^{\circ}C$ to $53^{\circ}C$. The antibacterial activity of KD-l, KD-2, or KD-3 against each other was not detected. That of KD-4 against KD-1, KD-2, or KD-3 was, however, detected. The organic compound and C/N ratio of compost fermented by the mixed culture were determined as 61.9% and 22.4%, respectively. The concentration of the ammonia gas was 12.35 mg/l in the liquid compost.

• Journal of Dairy Science and Biotechnology
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• v.34 no.2
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• pp.137-144
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• 2016

The ultimate research goal of the current study was a development of hydrolyzed whey protein powder (7%-GNANA) manufactured with normal content of sialic acid, a marker compound, that is naturally occurring at 7% concentration in GMP obtained from the milk protein. GMP is a safe food, used worldwide in infant and baby foods, etc. The test substance was prepared using (7% sialic acid containing) GMP as a raw material, and then using alcalase, an enzyme approved as a food additive, after separation of sialic acid with 100% efficiency and 7%-GNANA (containing 7% sialic acid and protein; product name: HELICOBACTROL-7) provided by MEDINUTROL Inc. (Korea). Bacterial reverse mutation (Ames) test was conducted in accordance with GLP Guideline using the test substance specified above. To identify its mutagenic potential against microorganisms, histidine auxotrophic strains of Salmonella Typhimurium, TA98, TA100, TA1535, and TA1537, and tryptophan auxotrophic strain of Escherichia coli, WP2uvrA, were used. The bacterial reverse mutation (Ames) test was performed by dividing the test substances into five different concentration groups (0, 61.7, 185, 556, 1,670, $5,000{\mu}g/plate$). Results of this experiment did not reveal repetitive increase of colony generating values or positive criteria for reverse mutagenicity for any concentration of test substances in any of the five strains, regardless of the presence of a metabolic activation system, and no dose-dependency was identified. In conclusion, the safety of 7%-GNANA test substance was verified by bacterial reverse mutation test conducted before registration of 7%-GNANA as a food additive.

• Journal of Dairy Science and Biotechnology
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• v.34 no.2
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• pp.91-98
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• 2016

The goal of this study was to develop hydrolyzed whey protein powder (23%-GNANA) manufactured with high content of sialic acid, a marker compound that is usually present at 7% concentration in GMP obtained from the milk protein. It is a safe food, used worldwide in infant and baby foods, etc. The test substance was prepared using (7% sialic acid containing) GMP as a raw material. Alcalase, an enzyme approved as a food additive, was used after separating sialic acid, with 100% efficiency, and 23%-GNANA (composed of 23% sialic acid and protein; product name: HELICOBACTROL-23), provided by MEDINUTROL Inc. (Korea), manufactured to have high (23%) content through ethanol soaking and enrichment. Bacterial reverse mutation (Ames) test was conducted in accordance with the GLP Guideline using the test substance specified above. To detect its mutagenicity potential in microorganisms, histidine auxotrophic strains of Salmonella typhimurium, TA98, TA100, TA1535, and TA1537, and tryptophan auxotrophic Escherichia coli strain, WP2uvrA, were used. The bacterial reverse mutation (Ames) test was performed using five concentrations of the test substances (0, 61.7, 185, 556, 1,670, $5,000{\mu}g/plate$). The evaluation did not reveal repetitive increase of colony generating values and positive criteria for reverse mutagenicity for any tested concentration in the five strains regardless of the presence of metabolic activation system, and no dose-dependency. In conclusion, the safety of 23%-GNANA test substance was verified by the bacterial reverse mutation test conducted before registration of 23%-GNANA as a food additive.

• Journal of Dairy Science and Biotechnology
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• v.34 no.2
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• pp.69-74
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• 2016

The main constituent of tea catechins, EGCG [(-)-Epigallocatechin-3-gallate], could inhibit the growth of various microorganisms and differently affect gram-positive and gram-negative bacteria. Antimicrobial activity of EGCG, a compound from green tea (Camellia sinensis) extract, against Cronobacter spp. and Salmonella spp. was studied to evaluate the possibility of using EGCG as a natural food additive in various dairy products. In pure TSB culture, the growth of Cronobacter spp. was suppressed below the detection limit (1 log CFU/mL) depending on EGCG concentration ($600{\sim}800{\mu}g/mL$), after 5~16 days at $4^{\circ}C$. Similarly, the growth of Salmonella spp. was suppressed below the detection limit (1 log CFU/mL) depending on EGCG concentration ($400{\sim}800{\mu}g/mL$), after 5~16 days at $4^{\circ}C$. Therefore, these results suggest that EGCG could be used as an effective additive to inhibit the growth of Cronobacter spp. and Salmonella spp. in various dairy products, such as yoghurt, cheese, dried infant powder, and so on.

• Korean Chemical Engineering Research
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• v.45 no.6
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• pp.554-559
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• 2007

In order to improve the reactivity for the direct synthesis of dimethyl carbonate (DMC) using methanol and carbon dioxide, the various additives were used in the DMC synthesis using $Ce_{0.8}Zr_{0.2}O_2$ catalyst, and then effect of the additives was investigated. The various additives were molecular sieves 3A and the compounds having the various functional groups such as sulfate, carbonate, nitrate and phosphate. As a result, the compound such as $K_2SO_4$ and $Na_2SO_4$ having sulfate group were the most effective additive among the various additives. When $K_2SO_4$ was used as an additive in the direct synthesis of DMC, the amount of DMC was about 0.91 mmol, which was the highest mount of DMC among using only-$Ce_{0.8}Zr_{0.2}O_2$ catalyst and the various additives.

• Journal of the Microelectronics and Packaging Society
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• v.30 no.4
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• pp.61-68
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• 2023

In this study, Sn-3.5Ag-15.0Fe composite solder was manufactured and applied to TLP bonding to change the entire joint into a Sn-Fe IMC(intermetallic compound), thereby applying it as a high-temperature solder. The FeSn₂ IMC formed during the bonding process has a high melting point of 513℃, so it can be stably applied to power modules for power semiconductors where the temperature rises up to 280℃ during use. As a result of applying ENIG surface treatment to both the chip and substrate, a multi-layer IMC structure of Ni₃Sn₄/FeSn₂/Ni₃Sn₄ was formed at the joint. During the shear test, the fracture path showed that cracks developed at the Ni₃Sn₄/FeSn₂ interface and then propagated into FeSn₂. After 2hours of the TLP joining process, a shear strength of over 30 MPa was obtained, and in particular, there was no decrease in strength at all even in a shear test at 200℃. The results of this study can be expected to lead to materials and processes that can be applied to power modules for electric vehicles, which are being actively researched recently.

• Korean Journal of Medicinal Crop Science
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• v.19 no.1
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• pp.1-8
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• 2011

Biological characteristics of 5 Zanthoxylum schinifolium (Zs) fruits such as Z1 (early August), Z2 (middle August), Z3 (middle September), Z4 (early October) and Z5 (middle October) according to harvesting time were evaluated. As fruits ripened, average weight of Zs increased from 4.8mg (Z1) to 50.7mg (Z5), while moisture contents decreased from 74.6% (Z1) to 55.2% (Z5). Crude fat contents of the fruits during ripening increased from 1% (Z1) to 10.6% (Z5). The major fatty acids in Zs were palmitic (C16:0), palmitoleic (C16:1), oleic (C18:1), and linoleic (C18:2) acids. Linoleic acid (C18:2) was a main fatty acid in Z1 and Z2, whereas oleic acid (C18:1) was found as a main one in the other Zs. The ratio of unsaturated fatty acid to total fatty acids increased from 60% (Z1) to 80% (Z3~Z5) during ripening. Among ripening stages, Z4 had the highest contents of total fatty acids ($3,355{\mu}g/g$) and total unsaturated fatty acids ($2,753{\mu}g/g$). Forty six volatile compounds in Zs were also identified. The major volatile compounds were ${\alpha}-pinene$, ${\beta}-myrcene$, ${\beta}-ocimene$, 2-nonanone, estragole, 2-undecanone, and ${\beta}-caryophyllene$. Major volatile components of Z1 were ${\beta}-ocimene$ (20.8 peak area %) and ${\alpha}-pinene$ (9.7 peak area %). In Z2, estragole (30.1 peak area %) was a main volatile compound, but the contents of ${\alpha}-pinene$ (0.4 peak area %), ${\beta}-myrcene$ (0.3 peak area %), and ${\beta}-ocimene$ (0.6 peak area %) were lower than those in Z1. Especially, estragole used as perfumes and as a food additive for flavor was drastically increased to 91.2 (Z3) and 92% (Z4) as fruits ripened.

• Applied Chemistry for Engineering
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• v.29 no.6
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• pp.670-676
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• 2018

Experiments on combustion gases generation of untreated cypress specimens or treated with boric acid, ammonium pentaborate, and boric acid/ammonium pentaborate additive were carried out. Test specimens were painted three times with 15 wt% boron compound aqueous solutions. After drying, the generation of combustion gas was analyzed using a cone calorimeter (ISO 5660-1). As a result, comparing to untreated specimen, the smoke performance index (SPI) of the specimens treated with the boron compound increased by 1.37 to 2.68 times and the smoke growth index (SGI) decreased by 29.4 to 52.9%. The smoke intensity (SI) of the specimens treated with boron compounds is expected to be 1.16 to 3.92 times lower than that of untreated specimens, resulting in lower smoke and fire hazards. Also, the maximum carbon monoxide ($CO_{peak}$) concentration of specimens treated with boron compounds was 12.7 to 30.9% lower than that of untreated specimens. However, it was measured to produce fatal toxicities from 1.52 to 1.92 times higher than that of permissible exposure limits (PEL) by Occupational Safety and Health Administration (OSHA). The boron compounds played a role in reducing carbon monoxide, but it did not meet the expectation of reduction effect because of the high concentration of carbon monoxide in cypress itself.