• Clean Technology
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• v.20 no.4
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• pp.383-389
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• 2014

$CO_2$ absorption processes have a good potential for large scale capture of $CO_2$ but a large amount of absorbing solution has to be regenerated, undesirably increasing the consumption of energy such as sensible heat and latent heat of vaporization. In this study, a cooling crystallization process which would separate the $CO_2$-rich potassium bicarbonate crystals from $CO_2$-lean water was developed to reduce the energy penalty. Sterically hindered alkanolamine additives were used to enhance the $CO_2$ removal efficiency and their antisolvent effect on the crystallization was found in a continuous cooling crystallizer. The production yields of crystals were increased in the sequence of 2-amino-2-methyl-1-propanol (AMP) < 2-amino-2-methyl-1,3-propanediol (AMPD) < 2-amino-2-hydroxymethyl-1,3-propanediol (AHPD), which are related to the number of hydroxyl groups in the additive molecules. Using $^{13}carbon$ nuclear magnetic resonance, the additives favored the formation of bicarbonate ions by steric hindrance effect and increased the supersaturation of $KHCO_3$. It is shown that the additives increase the mean size of crystals and crystal growth rate by increasing supersaturation. The additives are promising for enhancing the $CO_2$ removal efficiency and reducing the regeneration energy cost of $CO_2$ absorbing solution by promoting $KHCO_3$ crystallization.

• Clean Technology
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• v.20 no.2
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• pp.179-188
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• 2014

The effect of desorption pressure on $CO_2/N_2$ breakthrough behaviors for 4 different adsorbents was studied at a fixed bed. Zeolite 3A, 4A, 5A, and 13X pellets were used as adsorbents. Cyclic operations were executed with varying desorption pressure from vacuum (0 bar) to 3 bar while other conditions such as adsorption step pressure (3 bar), temperature (293 K), composition ($CO_2:N_2=10:90$vol%) and flow rate (400 ccm) were fixed at constant values. Each adsorption and desorption step was set as 80 min, which totaled up to 160 min per a cycle. 5 cycles with adsorption and desorption steps were run overall. After the experiment, breakthrough time, saturation time, and adsorption amount were measured and compared in order to find an optimum adsorbent and a proper operating condition for a post combustion $CO_2$ capture process.

• Clean Technology
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• v.24 no.1
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• pp.50-54
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• 2018

In this work, N-methyl-2-pyrrolidone (NMP) was added into diethylenetriamine (DETA) aqueous solution for high $CO_2$ loading via phase splitting of absorbents during $CO_2$ absorption. Immiscible two phases were formed in the range of more than 30 wt% of NMP in 2 M DETA + NMP + water absorbents because of low solubility of DETA-carbamate in NMP solution. As the composition of NMP in the absorbents increased, the difference of $CO_2$ loading between each phase increased and the volume of bottom phase decreased. In $CO_2$ absorption in packed column by 2 M DETA + NMP + water absorbents, the absorption rate decreased in the range of more than 40 wt% of NMP. It is due to the increasing of mass transfer resistance in liquid film of absorbents at the high concentration of NMP. DETA + NMP + water absorbent is expected as the promising one for reducing the regeneration energy of absorbents according to volume reduction of $CO_2-rich$ phase.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.9
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• pp.613-622
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• 2012

A chrome absorbent that is useful in rapid magnetic recovery and recycling was developed though a synthesis of Multi-Terminalized Magnetic-core Dendrimer (MTMD). Divergence through coprecipitation and rotation growth was used for synthesis. The dendrimer was multi-terminilized through methyl propionate and glutaric acid. The property analysis of the synthesized sample was performed through XRD, FT-IR, TEM, EDS, TGA and zeta potential analyzer. A magnetic-core of MTMD had a magnetite crystal and the size of 4th generation dendrimer was identified to be from 15 nm to 20 nm. Through the analysis of the TGA, the rate of the dendrimer branch for the first generation dendrimer was about 7% and 3% of diminished weight occurred as the generation grows. Also, the potential of the dendrimer when multi-terminalized, had variation from 25.26 mV to -6.53 mV. As a result of MTMD adsorption experiment, it absorbed more than 80% within 5 minutes and indicated absorptivity of 6.308 mg/g. When it was compared with COOH Dendrimer (COOH-D) after magnetic recovery, the recovery time was rapidly reduced by more than half and it could recover 100% within 30 minutes. In case of the regeneration experiment that used chrome, it was identified to maintain the same adsorptivity for four runs.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.2
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• pp.210-224
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• 2003

Sulfate reduction is a microbiological process which occurs ubiquitously in anaerobic marine environment. Sulfate reducing bacteria play a significant role in anaerobic decomposition of organic matter and regeneration of inorganic nutrients which supports the primary production in the water column (i.e., benthic-pelagic coupling) and, in special case, could be responsible for the harmful algal bloom in the coastal marine environment. Summary of the sulfate reduction rates reported in various marine sedimentary environments revealed that supply of organic substrates and presence of various electron acceptors (i.e., $O_2$, NO$_{3}$$^{[-10]}$ , Fe(III) and Mn(IV), etc.) for other aerobic and anaerobic respiration directly affect the sulfate reduction rate and relative significance of sulfate reduction in organic matter mineralization. Significance of temperature, macrophytes and bioturbation is discussed as factors controlling supply of organic substrates and distribution of electron acceptors. Finally, we suggest studies on the anaerobic microbiological processes associated with biogeochemical element cycles in the coastal environments of Korea where massive operation of organic enriched fish cage farm, frequent occurrence of toxic algal bloom and hypoxia and conservation of tidal flat are of major environmental issues.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.32 no.3
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• pp.58-76
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• 2019

Objectives : This study was designed to examine the effects of Daecheonglyong-tang(DCL) on atopic dermatitis induced by DNCB in mice Methods : The Nc/Nga mice were divided into 5 groups, and four groups excluding the normal group were applied by 2,4-dinitrochlorobenzene(DNCB), to cause AD and were orally administered with distilled water(negative control), dexamethasone(positive control), and DCL 200 or 400mg/kg once a day for 4 weeks respectively. The visual changes on skin, changes in skin tissue thickness and eosinophil infiltration were observed. IgE, Histamine, Cytokines, immune cells and the amount of gene expression of filaggrin, VEGF, $TGF-{\beta}1$, EGF were measured. Results : Dermatitis score showed a gross improvement on all DCL groups, similar to or better than positive control. All DCL groups showed no significant change in the basophils, while neutrophils and eosinophils decreased. In only DCL 400 mg/kg groups, white blood cells and mononuclear cells were decreased and lymphocytes were increased. In particular, neutrophils had similar or better effects than the positive control. In all DCL groups, IgE, Histamine, $IL-1{\beta}$, IL-4, IL-5, IL-6 and $TNF-{\alpha}$ were decreased and IL-2 was increased. In only DCL 400 mg/kg groups, IL-10 decreased and $IFN-{\gamma}$ increased. In particular, $IL-1{\beta}$ and $IFN-{\gamma}$ showed a similar rate of increase and decrease comparing positive control in DCL 400 mg/kg. $TGF-{\beta}$1 was increased in all DCL groups, filaggrin and VEGF were increased in only DCL 400 mg/kg groups. EGF did not make any changes. Epidermis, dermis thickness and eosinophil infiltration were also decreased in all DCL groups. Conclusions : By increasing Th1 cytokine and decreasing Th2 cytokine, DCL extracts appear to be effective in controlling immune response imbalances, anti-inflammatory and skin regeneration and are likely to be available as a treatment for AD.

• Journal of Ginseng Research
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• v.43 no.1
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• pp.38-48
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• 2019

Background: Interspecific ginseng hybrid, Panax ginseng ${\times}$ Panax quenquifolius (Pgq) has vigorous growth and produces larger roots than its parents. However, F1 progenies are complete male sterile. Plant tissue culture technology can circumvent the issue and propagate the hybrid. Methods: Murashige and Skoog (MS) medium with different concentrations (0, 2, 4, and 6 mg/L) of 2,4-dichlorophenoxyacetic acid (2,4-D) was used for callus induction and somatic embryogenesis (SE). The embryos, after culturing on $GA_3$ supplemented medium, were transferred to hormone free 1/2 Schenk and Hildebrandt (SH) medium. The developed taproots with dormant buds were treated with $GA_3$ to break the bud dormancy, and transferred to soil. Hybrid Pgq plants were verified by random amplified polymorphic DNA (RAPD) and inter simple sequence repeat (ISSR) analyses and by LC-IT-TOF-MS. Results: We conducted a comparative study of somatic embryogenesis (SE) in Pgq and its parents, and attempted to establish the soil transfer of in vitro propagated Pgq tap roots. The Pgq explants showed higher rate of embryogenesis (~56% at 2 mg/L 2,4-D concentration) as well as higher number of embryos per explants (~7 at the same 2,4-D concentration) compared to its either parents. The germinated embryos, after culturing on $GA_3$ supplemented medium, were transferred to hormone free 1/2 SH medium to support the continued growth and kept until nutrient depletion induced senescence (NuDIS) of leaf defoliation occurred (4 months). By that time, thickened tap roots with well-developed lateral roots and dormant buds were obtained. All Pgq tap roots pretreated with 20 mg/L $GA_3$ for at least a week produced new shoots after soil transfer. We selected the discriminatory RAPD and ISSR markers to find the interspecific ginseng hybrid among its parents. The $F_1$ hybrid (Pgq) contained species specific 2 ginsenosides (ginsenoside Rf in P. ginseng and pseudoginsenosides $F_{11}$ in P. quinquefolius), and higher amount of other ginsenosides than its parents. Conclusion: Micropropagation of interspecific hybrid ginseng can give an opportunity for continuous production of plants.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.37-37
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• 2021

Calystegia soldanella L. is a perennial herbaceous halophyte belonging to the convolvulaceae family, which mainly grows in coastal sand dunes in Korea. Shoots and rhizomes are edible, and roots called 'Hyoseon Chogeun' are known to have medicinal effects such as antipyretic, sterilization, and diuretic. In addition, physiological activities of antioxidant, anti-inflammatory, antiviral, antifungal and PTP-1B (protein tyrosine phosphate-1B) inhibition have been reported. In this study, in vitro induction cell lines of C. soldanella L. collected from the coastal sand dunes in Jeju island was redifferentiated into adventitious roots that can be used as medicinal resources. Also the biomass of mass-proliferated adventitious roots using a bioreactor were evaluated. Plants of C. soldanella L. were collected from the crevice of the seashore in the coastal area of Taeheung 2-ri, Namwon-eup, Seogwipo-si. Then, it was separated into leaves, stems, rhizomes, and roots, and surface sterilized with 70% ethyl alcohol and 2% NaOCl (sodium hypochlorite). After washing with sterilized water, each organ section was cultured in Hormone-free MS medium (Murashige & Skoog Medium). As a result, the induction response rates were evaluated at 85% and 55%, respectively, in terms of callus formation and shoot generation in the rhizome segment. In the case of the adventitious roots morphological characteristics induced by single-use treatment of auxin-based plant growth regulators IBA and NAA from redifferentiated shoots were compared. Most efficient adventitious root culture method as a rooting rate, number, length, and biomass proliferation in the bioreactor system was confirmed when treated by culturing in MS salts, Sucrose 30 g·L^-1, and IBA 1mg·L^-1 for 4 weeks. In this study, the medium composition and culture period were confirmed using a bioreactor system to mass-proliferate adventitious roots derived from C. soldanella L. in Jeju island. Also this adventitious root line developed a new medicinal material could increase value of the bio-industry ingredient through quantitative and qualitative screening of phyto-bioactive compounds.

• The Korean Journal of Mycology
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• v.51 no.4
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• pp.389-396
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• 2023

In this study, dikaryotic strains of Lentinula edodes were generated by mono-mono hybridization using mating type analysis and their fruiting body characteristics were investigated. Approximately 100 monokaryotic strains were isolated from the basidiospores of Sanbaekhyhang, and homokaryotic strains were isolated from Chungheung 1ho using protoplast isolation and regeneration. Their mating types were evaluated and a total of 60 dikaryotic strains were hybridized. Using these strains, fruiting bodies were produced and their characteristics were examined after cultivation on sawdust media. The results indicated that the rate of hybridization was 100% and that 55 of 60 strains formed fruiting bodies. These showed normal pileus and gill structures; however,10 strains also produced fruiting bodies with abnormal pileus and gill structures. The weight and size of the fruiting bodies differed depending on the strains. Overall, further studies are needed for predicting the characteristics of hybridized strains based on their parental strains.

• Journal of the Korea Organic Resources Recycling Association
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• v.32 no.2
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• pp.15-25
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• 2024

In this study, the regeneration effect of pressurized water and ultrasonic cleaning was investigated for contaminated filter cloth from the sewage sludge filter press process. For this purpose, contaminated filter cloth was collected from a 3-ton sewage sludge hydrothermal carbon treatment filter press. First, the contamination characteristics were analyzed. According to the location of the filter cloth, air permeability and unit mass were measured, and compared with the values of a new filter cloth. Next, the results were mapped over the entire area to evaluate the contamination characteristics. Finally, pressure cleaning at 3 bar and ultrasound at frequencies of 34, 76, 120, and 168 kHz were performed on the contaminated filter cloth. In addition, the cleaning efficiency was evaluated by 3 levels of contamination degree. As a result, pore contamination occurred mainly at the bottom and both sides of the filter cloth, where the filter material was continuously injected and compressed. Surface contamination appeared evenly over the entire area. As a result of washing, air permeability increased by 1.3-3.1%p and contaminant removal was by 2.7-4.4% under pressure. In ultrasonic cleaning, air permeability increased by 12.5-61.5%p and contaminants were removed by 2.7-29.2%. In ultrasonic cleaning the lower the frequency, the higher air permeability and contaminant removal rate. Also, The higher pore contamination level, the better the air permeability improvement and contaminant removal.