• Journal of Plant Biotechnology
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• v.8 no.1
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• pp.21-25
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• 2006

Phragmites australis (reed) has received much attention as being one of the principle emergent aquatic plants for treating industrial and civil wastewater. Plant regeneration via plant tissue culture in p. australis was investigated. Three types of callus were identified from seeds on N6 medium plus 4.5 UM 2,4-dichlorophenoxyacetic acid (2,4-D). Yellow compact type showed the best redifferentiation, whereas white compact type and yellow friable were not competent to differentiate into plane. Solid medium culture was better than liquid suspension culture for enhancing callus growth when N6 medium supplemented with 4.5 ${\mu}M$ 2,4-D was used. Phytagel, as a gelling agent, was superior to agar in plant regeneration on N6 medium, supplemented with 9.4 ${\mu}M$ kinetin and 0.54 ${\mu}M$ $\alpha$-naphthaleneacetic acid (NAA). Transfer of the plantlets regenerated from kinetin and NAA-supplemented N6 medium to growth regulator-free MS medium enhanced the further development of the plantlets. Plantlets on subsequently grown to maturity when tansferred to potting soil. The regenerated plants exhibited morphologically normal. The system for plant regeneration of P. australis enables to propagate elite lines on a large scale for water purification in the ecosystem

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.3
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• pp.104-109
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• 2023

Electrospinning was performed using an eco-friendly solvent composed of acetic acid, ethyl acetate and distilled water to investigate the effect of gelatin concentration on mechanical properties and cytotoxicity of absorbable poly(D,L-lactic acid) (PDLLA)/gelatin blend membrane. The tensile stress, strain at break, and WUC of the PDLLA/gelatin (97/3) scaffold at 26 wt% concentration were determined to be 3.9 ± 0.7 MPa, 37 ± 1.3 %, and 273 ± 33 %, respectively. FT-IR results revealed that PDLLA and gelatin were bound only by van der Waals interactions. The cell viability of PDLLA/gelatin membranes containing 0 %, 1 %, 2 %, 3 %, and 4 % gelatin were more than 100 %, which makes all membranes highly suitable as a barrier membrane for absorbable periodontal tissue regeneration due to their marketed physical properties and biocompatibility.

• Korean Journal of Plant Resources
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• v.30 no.6
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• pp.612-617
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• 2017

The preservation of pear germplasm, like that of other clonal germplasms, is difficult because it requires conservation of whole plants or their tissues. Among the currently available methods for long-term conservation of clonal germplasm, cryopreservation of shoot tips is the most reliable and cost- and space-effective option. Alginate-coated axillary shoot tips from in vitro-grown pear were conserved successfully in liquid nitrogen (LN) following dehydration. Shoot recovery from cryopreserved shoot tips was improved greatly after 8 weeks of cold acclimation, but recovery decreased slightly after then. The highest regeneration rate was observed when in vitro shoot tips were preincubated in MS (Murashige and Skoog) medium with 0.3 M sucrose for 48 h, and when alginate-coated shoot tips were precultured in MS medium with increasing sucrose concentrations (0.5 M and 0.7 M) for 8 and 16 h, respectively. When the encapsulated beads were dehydrated for up to 7 h [25% water content (fresh weight basis)] under laminar flow, the highest regeneration rate was observed in "BaeYun No. 3" (55.7%) and "Whanggeum" (43.3%) after warming from LN. This technique is useful as a practical procedure to cryopreserve plant material that is sensitive to freezing of the surrounding cryoprotectant medium. Therefore, this technique appears to be promising for the cryopreservation of shoot tips from in vitro-grown plantlets of pear germplasm.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.2
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• pp.116-121
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• 2014

In order to study the improvement of the multi stage regeneration cycles, muti-stage processes were applied to the cycles, respectively or together. The kinds of the cycles are multi stage reheater cycle (MS) and multi stage reheater regeneration cycle (MSR). Working fluid used was R134a and R245fa. Temperature of the heat source was $65^{\circ}C$, $75^{\circ}C$, and $85^{\circ}C$, and temperature of the heat sink was $5^{\circ}C$. Optimization simulation was conducted for improving the gross power and efficiency with multi stage reheater regeneration cycle for ocean thermal energy conversion(OTEC) with changing of a heat source, kind of the working fluid, and type of the cycle. Performance analysis of the various components was simulated by using the Aspen HYSYS for analysis of the thermodynamic cycle. R245fa shows better performance than R134a. This paper showed the most suitable working fluid with changing of a heat source and the kinds of working cycle. Compared to each other, MS showed better performance at gross power and MSR showed higher cycle efficiency.

• Journal of Korea Water Resources Association
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• v.46 no.8
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• pp.843-855
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• 2013

In the modern society with high science and technological level, many people have been tried to mitigate natural disaster. The disaster was so huge that we made special service organization which deal with 'The Natural Disaster Endangered Districts'. But the analysis of the organization's works was inadequate. In order to analyze their regeneration project, this study selected analysis area and did a spot survey. We did validity, reliability tests and statistical data analysis of this survey. We also did reliability analysis of this policy using Structural Equation Model. According to the result, there is a reasonable suitability in 'The Natural Disaster Repair work Policy'. And it also improved spiritual, substantial environment of the surrounding people. The people formed positive awareness about Government Repairing Policy. This 'Natural Disaster Repair work Policy' is essential to improve and develop local community. Therefore it will affect democratic development of society.

• Biomolecules & Therapeutics
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• v.23 no.1
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• pp.90-97
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• 2015

Water chestnut (Trapa japonica Flerov.) is an annual aquatic plant. In the present study, we showed that the treatment of water chestnut extracted with boiling water resulted in a significant increase 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity and decrease the intracellular $H_2O_2$-induced accumulation of reactive oxygen species. In addition, water chestnut extract (WCE) inhibited lipopolysaccharide (LPS)-induced nitric oxide production and suppressed mRNA and protein expression of the inducible nitric oxide synthase gene. The cytokine array results showed that WCE inhibited inflammatory cytokine secretion. Also, WCE reduced tumor necrosis factor-${\alpha}$- and interleukin-6-induced nuclear factor-${\kappa}B$ activity. Furthermore, during sodium lauryl sulfate (SLS)-induced irritation of human skin, WCE reduced SLS-induced skin erythema and improved barrier regeneration. These results indicate that WCE may be a promising topical anti-inflammatory agent.

• Journal of Korean Society on Water Environment
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• v.34 no.1
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• pp.57-66
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• 2018

Water disasters such as flash floods and inundation caused by localized heavy rainfall in urban areas have a large impact on climate change but are also closely related to the increase in impervious areas as pointed out in domestic and international studies. It is difficult to secure natural green areas in urban areas that have already been developed. So, urban regeneration can be expected using water management optimized with technologies to secure infiltration and storage capacity such as Low-Impact Development technology. In this study, the water cycle improvement ability was confirmed by applying the LID technology within the district unit plan of the environmentally friendly village, and the economic feasibility of LID application was analyzed by estimating the costs and benefits of installing the facilities. The site was planned to conserve sufficient green and plans for securing the watershed infiltration and storage capacity were formulated with the application of additional LID technology, such as infiltration trenches, rain barrels and permeable pavements. The LID design method applicable to the site was established, and the water balance of the watershed was analyzed through simulations of the SWMM model. The water circulation improvement effect was confirmed through the water balance analysis, and the cost-benefits were determined according to the estimation method, and the economic analysis was conducted. This study confirms that the investment of LID technology is economically feasible for the hydrological improvement effect of the housing complex.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.250.2-250.2
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• 2014

Currently, teeth whitening method which is applicable to dental surgery is that physician expertises give medical treatment to teeth directly dealed with a high concentration of hydrogen peroxide and carbamide peroxide. If hydrogen peroxide concentration is too high for treatment of maximized teeth whitening effect [1], it is harmful to the human body [2]. To the maximum effective and no harmful teeth whitening effect in a short period of time at home, we have observed the whitening effect using carbamide peroxide (15%) and a low-temperature atmospheric pressure plasma jet which is regulated by the Food and Drug Administration. The gas supplied conditions of the non-thermal atmospheric pressure plasma jet was with the humidified (0.6%) gas in nitrogen or air at gas flow rate of 1000 sccm. Also, the measurement of chemical species from the jet was carried out using the optical emission spectroscopy (OES), the evidence of increased reactive oxygen species compared to non-humidified plasma jet. We have found that the whitening effect of the plasma is very excellent through this experiment, when bovine teeth are treated in carbamide peroxide (15%) and water vapor (0.2 to 1%). The brightness of whitening teeth was increased up to 2 times longer in the CIE chromaticity coordinates. The colorimetric spectrometer (CM-3500d) can measure color degree of whitening effect.

• Korean Chemical Engineering Research
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• v.47 no.3
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• pp.349-354
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• 2009

In this study, a bubbling fluidized-bed reactor was used to study $CO_2$ capture from flue gas using a potassium-based dry sorbent. A dry sorbent, manufactured by the Korea Electric Power Research Institute, consists of 35% of $K_2CO_3$ for $CO_2$ absorption and 65% of supporters for mechanical strength. $H_2O$, a reactant of the carbonation reaction, was supplied in the reactor as a form of saturated water vapor at a given temperature. The experiment of the regeneration reaction was performed by raising up to a given temperature using $N_2$ as a fluidization gas. It was indicated that sorption capacity and regenerability of dry sorbents showed high-efficiency at $1.97\;mol\;H_2O/mol\;CO_2$ and $400^{\circ}C$, respectively. The regenerated sorbent samples were analyzed by TGA to confirm the extent of the reaction. When the regeneration temperature was $150^{\circ}C$, the regenerability of dry sorbents was about 60%, which was capable of applying those sorbents to a two-interconnected fluidized-bed reactor system with continuous solid circulation. The results obtained in this study can be used as basic data for designing and operating a large scale $CO_2$ capture process with two fluidized-bed reactors.

• Journal of Ecology and Environment
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• v.43 no.2
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• pp.271-281
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• 2019

Background: The plant communities within reservoir drawdown zones are ecologically important as they provide a range of ecosystem services such as stabilizing the shoreline, improving water quality, enhancing biodiversity, and mitigating climate change. The aim of the study was therefore to identify the major environmental factors affecting these plant communities within the drawdown zone of the Soyangho Reservoir in South Korea, which experiences a monsoonal climate, and thereafter to (1) elucidate the plant species responses and (2) compare the soil seedbank composition along main environmental gradients. Results: Two main environmental gradients affecting the plant community structure were identified within the drawdown zone; these were a vertical and longitudinal gradient. On the vertical dimension, a hydrological gradient of flood/exposure, the annual-dominated plant community near the water edge changed to a perennial-dominated community at the highest elevation. On the longitudinal dimension from the dam to the upstream, plant species composition changed from an upland forest-edge community to a lowland riverine community, and this was correlated with slope degree, soil particle size, and soil moisture content. Simultaneously, the composition of the soil seedbank was separated along the vertical gradient of the drawdown zone, with mainly annuals near the water edge and some perennials at higher elevations. The species composition similarity between the seedbank and extant vegetation was greater in the annual communities at low elevation than in the perennial communities at higher elevation. Conclusions: The structures of plant community and soil seedbank in the drawdown zone of a monsoonal riverine reservoir were changed first along the vertical and secondly along the longitudinal gradients. The soil seedbank could play an important role on the vegetation regeneration after the disturbances of flood/exposure in the drawdown zone. These results indicate that it is important to understand the vertical and longitudinal environmental gradients affecting shoreline plant community structure and the role of soil seedbanks on the rapid vegetation regeneration for conserving and restoring the drawdown zone of a monsoonal reservoir.