• Journal of Adhesion and Interface
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• v.17 no.4
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• pp.141-148
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• 2016

In this work, mesoporous silica (SBA-15) was synthesized via self-assembly process using triblock copolymer ($PEO_{20}PPO_{70}PEO_{20}$, P123) as template and tetraethyl orthosilicate (TEOS) as silica source under acidic condition. SBA-15 have high surface area ($704m^2g^{-1}$) and uniform pore size (8.4 nm) with well-ordered hexagonal mesostructure. Spiropyran-functionalized SBA-15 (Spiropyran-SBA-15) was synthesized via post-synthesis process using 3-(triethoxysilyl)propyl isocyanate (TESPI) and 1-(2-Hydroxyethyl)-3,3-dimethy-lindolino-6'-nitrobenzopyrylo-spiran (HDINS). Spiropyran-SBA-15 was produced with hexagonal array of mesopores without damage of mesostructre. Surface area and pore size of Spiropyran-SBA-15 were $651m^2g^{-1}$ and 8.0 nm, respectively. Optochemical properties of Spiropyran-SBA-15 was studied with chemical vapors such as EtOH, THF, $CHCl_3$, Acetone and HCl. Main peaks of photofluorescence of Spiropyran-SBA-15 exhibited blue shift in the range of 603.4~592.1 nm after exposure under EtOH, THF, $CHCl_3$, and Acetone vapors. Normalized peak intensities decreased in the range of 0.8~0.3. The main peak of photofluorescence of Spiropyran-SBA-15 showed significant blue shift of 592.1 nm after exposure under HCl vapor, while normalized peak intensity decreased to 0.1.

• Journal of Radiation Protection and Research
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• v.8 no.1
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• pp.15-25
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• 1983

The sequential separation of Ru-103, Cs-137 and Ce-144 was carried out by organic cation exchanger, Amberite CG-120, and inorganic ion exchangers, silica gel and montmorillonite. The optimum conditions of Ru-103, Cs-137 and Ce-144 on Amberite CG-120 are 0.01M-, 0.01M- and 0.1IM- hydrochloric acid for the adsorption, and 3M-, 3M- and 5M-hydrochloric acid for the desorption, respectively. The optimum conditions of Ru-103, Cs-137 and Ce-144 on silica gel are pH 8, pH 8 and pH 8 for the adsorption. and 3M-, 1M- and 1M-hydrochloric acid for the desorption. respectively. The optimum conditions of Ru-103, Cs-137 and Ce-144 on montmorillonite are pH 8, 0.01M-hydrochloric acid and pH 4 for the adsorption, and 1M-, 5M- and 3M-hydrochloric acid for the desorption. respectively. The adsorption which occurs at lower ionic strength and the differences in desorption ionic strength are utilized for the separation of tracer mixture in continuous experiments. The individual separation of Ru-103, Cs-137 and Ce-144 can be carried out more efficiently with montmorillonite than with silica gel and Amberite CG-120.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.9
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• pp.735-742
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• 2009

The bone of spinal animals has a hydroxylapatite ($Ca_{10}(PO_4)_6(OH)_2$, HAp) structure which is well known as an excellent inorganic ion exchanger for various heavy metal ions in solutions. In this study, the reusability of cow-bone, pig-bone and fish-bone as a potential material for the removal of heavy metals in solutions was evaluated from the removal of Cu(II) ion in batch tests. The surface properties of three bones, calcined at different temperatures, were measured with SEM, XRD, FT-IR analyses. From the SEM analysis, a clear development of heterogeneity as well as pores having small diameter was observed as the calcination temperature increased. The results of X-ray diffraction analysis showed well developed crystallinity on the surface of calcined bones obtained at higher temperatures, suggesting a transform of amorphous type to crystalline type. Fourier transform infrared (FT-IR) analysis showed disappearance of water molecule on the surface of HAp and organic functional groups of the HAp with increasing the calcination temperatures. Cu(II) removal in the control test was below 15%. By the way, additional 40% increase of Cu(II) removal was observed in the presence of calcined bones. For three bones, Cu(II) removal was decreased as the calcined temperature increased. Cu(II) removal was increased as the solution pH increased due to a favorable condition for the cation exchange as well as precipitation.

• Journal of Soil and Groundwater Environment
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• v.10 no.5
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• pp.18-24
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• 2005

Water quality changes of wastewater effluent in the shallow aquifier condition was investigated using laboratory unsaturated and saturated SAT columns for over five months. Average DOC removal was 31.9% in the unsaturated SAT column whereas no removal occurred in the saturated SAT column. Under the shallow aquifer condition, nitrification was not completed in the unsaturated SAT column, releasing residual ammonium nitrogen into the saturated SAT column. Short retention time (one day) in the shallow unsaturated SAT column rendered DO of about 2 mg/L to the influent of the saturated SAT column. Phosphate was not removed at all in the unsaturated SAT column while complete removal was achieved in the saturated column. Consequently, organic and inorganic compounds were removed under the shallow aquifer condition as effectively as was in deep aquifer, except for the release of ammonium and relatively high DO into the saturated SAT column.

• Journal of Biomedical Engineering Research
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• v.16 no.3
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• pp.331-336
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• 1995

A composite material was produced as an artificial bone substitute which is gradually degrAded and replaced by the regenerated natural bones after implantation. To detect the effect of the material on the cell's activity, the composite specimens were placed in MEMs and incubated at $37^{\circ}C$ for one week. Human uterus cervical cancer origin HeLa 3 cells and mouse subcutaneous origin L929 cells were cul- tured in the specimen dissolved MEMs for 5 days to investigate cytotoxicity via cell growth rates. ${Na_2}^{51}CrO_4$ solution was added to the media, to label the HeLa 53 cells, and the released amount of $^{51}Cr$ was measured by a $\gamma$-counter. On the cell growth investigation, no significant cytotoxic phenomena were revealed in both HeLa S3 and L929 cell cultures. On the released 51CR from the incubated HeLa 53 cells, no significant cell degeneration was observed from the composite embedded MEMs.

• Journal of Environmental Science International
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• v.26 no.6
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• pp.691-710
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• 2017

This study was performed to investigate the geochemical and benthic environment of three shellfish farms in Suncheon Bay during the period of September 2014 ~ April 2015. Three sampling stations were selected; St.1 is the shellfish farm of razor clam near Jangsan area. St.2 is the shellfish farm of small ark shell near Hwapo area and St.3 is the shellfish farm of razor clam near Yongdu area. Razor clam was the dominant species at St.1, small ark shell and granulated ark shell were dominant at St.2 and St.3, respectively. Granulated ark shell inhabited St.3, although it is not cultured at that station. This station's exposure to air during the ebb tide and sediment composition likely provides the appropriate habitat for granulated ark shell species. Analysis of the number of different species showed that 8 benthos species were found to be distributed at St.1, 18 species at St.2, and 13 species at St.3. Among three stations, the highest Ignition Loss (IL), Chemical Oxygen Demand (COD) and Acid Volatile Sulfide (AVS) values were obtained from the sediment at St.2. The analysis of pore water from St.2 also showed the highest values of Total Organic Carbon (TOC), ammonia ($NH_4^+$), Dissolved Inorganic Nitrogen (DIN) and phosphate ($PO_4^{3-}$). These results are related to the fact that species dominance and richness is the highest in St.2.

• KSBB Journal
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• v.15 no.3
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• pp.285-292
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• 2000

Support media for yeast immobilization was prepared from a porous volcanic rock used as a moisturizer in orchid growing. The rock was broken to the size of 2-3 mm and burned at $600^{\circ}C$ in a furnace in order to remove organic materials blocking the pores or treated with HCI solution or NaOH solution to remove the inorganic dirts by dissolving. Even through both the acid and the akali solution were effective the latter was not recommendable because it broke the pore structure by dissolving the elements of the media. This media was mainly consisted of SiO2 with $Al_2O_3$ as a minor component and CaO and K2O as trace elements. It had the finely developed pores of $15-80\mu\textrm{m}$size. Yeast immobilization capacity of this media was about $5{\times108}$ cells/ml bed which is large enough to be used for the practical applications. Yeast immobilization capacities of Alumina and Cordierite were much smaller than that of silica-based media. Scanning electron micrograph of Cordierite and Alumina showed uneven surfaces and small size of pores in contrast to relatively smooth surface and large pores of silica based media which means that smooth surface and large pores are desirable for the good adsorption of microbes on the media.

• Economic and Environmental Geology
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• v.36 no.3
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• pp.171-176
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• 2003

The fate and behavior of polycyclic aromatic hydrocarbons(PAHs) and heavy metals in the environment are mainly controlled by their interactions with various components of soils and sediments. Due to their large surface area and abundance in many soils, smectites may greatly influence the fate and transport of the contaminants. In our experiment, PAH sorption by hexadecyltimethylammonium(HDTMA)-modified smectite linearly increased in proportion to the amount of HDTMA added on the clay. However, trimethylammonium(TMA)-modified smectite did not show superiority in its sorption of PAH compared with the HDTMA-smectite or dodecyltrimethylammonium(DTMA)- smectite. Meanwhile, the smectites modified with the same cationic surfactants adsorbed Cd$^{2＋}$(heavy metal) significantly from water at low surfactant loading level, but the Cd$^{2＋}$ adsorption linearly decreased as the loading of surfactant increased. The result shows that the sorption tendency of organoclays for organic or inorganic contaminants was significantly influenced by the amount and size of the surfactants added on the clay. This reveals that the stabilization and configuration of cationic surfactant formed on the clay interlayer of different sizes may be an important factor in controlling the sorptive capacity of each pollutant in the environment.

• Korean Journal of Food Science and Technology
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• v.8 no.1
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• pp.33-41
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• 1976

These experiment were conducted to investigate the cultural condition of the lipase production by Rhizopus japonicus. The results obtained were as follows: 1. Soybean meal and ammonium sulfate were the most effective in the lipase production as organic and inorganic nitrogen sources, respectively. 2. The lipase production was strongly inhibited, when added as carbon sources xylose, glucose, fructose, galactose, maltose, soluble starch, and dextrin causing the lowering of pH of the medium during culture. Sucrose did not inhibit the lipase production, but not caused any effect when added. 3. $K_2HPO_4$ as phosphate salt and $MgSO_4{\cdot}7H_2O$ as magnesium salt were the most effective in the lipase production. 4. The addition of olive oil, soybean oil, and coconut oil respectively increased the enzyme production and especially 1% olive oil increased it by 50%. 5. The enzyme production increased slightly on the addition of yeast extract to $0.05{\sim}0.07%$. 6. The optimum composition of the medium for the lipase production by Rhizopus japonicus was in the composition of soybean meal 2%; $K_2HPO_4{\cdot}$ 0.5%; $(NH_4)_2SO_4$ 0.1%; $MgSO_4\;7H_2O$ 0.05%; yeast extract 0.05%; olive oil 1%. The maximum production of the lipase was attained by the incubation far 48hrs under the optimum incubation condition.

• Korean Journal of Food Science and Technology
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• v.9 no.2
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• pp.97-105
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• 1977

1) In order to obtain a microbial strain having a strong yeast cell wall lytic activity, about 156 isolates capable of forming clear zones on baker's yeast-peptone-bouillon agar plate were obtained from soil, mud and water samples and a strain K-42 with the highest lytic activity was identified as Bacillus circulans. 2) Effect of carbon sources on the lytic enzyme production by the K-42 strain was in the decreasing order of maltose>glucan>xylose>control in 2-day culture and of lactose>galactose>glucan>control in 3-day culture. Effect of inorganic nitrogen sources was in the decreasing order of ammonium acetate>sodium nitrate>control in 2-day culture and of ammonium chloride>ammonium oxalate>control in 3-day culture, whereas organic nitrogen sources except milk casein showed an increase in 2-day culture and a decrease in 3-day culture. Synergistic effect of carbon sources and nitrogen sources was not observed. 3) The enzyme production by the K-42 strain was greatly affected by pH change of the culture medium, thus a high lytic activity could be maintained by keeping the pH range of $7{\sim}8$ and adding carbon or nitrogen sources. 4) Optimum conditions for the lytic activity of the K-42 strain were obtained at $pH\;7{\sim}8$ and $60^{\circ}C$ and the extent of hydrolysis toward heated yeast cell wall was 65%.