• Proceedings of the SAREK Conference
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• 2007.11a
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• pp.322-327
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• 2007

Dedicated outdoor air-conditioning(DOA) system that utilizes pre-cooling and desiccant dehumidification can be superior to conventional cooling and reheating system with respect to energy consumption and indoor thermal comfort. In this work, simulation has been conducted to study various factors that affect the performance of DOA. Dynamic simulation shows the transient variation of temperature and humidity as the on/off control logic is imposed. Exit humidity of process air and flow rate are varied to study the effect on exit temperature of process air, dehumidification quantity, required regeneration temperature and exit humidity of regeneration air. For an outdoor air condition of $28.5^{\circ}C$ temperature, 16 g/kg humidity ratio and 2000 cmh flow rate, the dehumidification efficiency is increased by 4.6% as the flow rate is doubled.

• Journal of Plant Biotechnology
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• v.1 no.2
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• pp.91-95
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• 1999

Genetic engineering of stone fruit species like apricot, plum, peach and cherry are hampered by the inefficient and low-level regeneration processes in tissue culture. The first transgenic stone fruit species have emerged from transformed hypocotyls. These great achievements were applauded by the scientific community contrary the fact that hypocotyl derived transgenic plants have no real brooding value. Tissue culture of different organs of valuable cultivars are recorded with an extremely low-level of regeneration in the literature. To improve the tissue culture basis of stone fruit plants an extensive tissue culture programme were launched and dozens of different media were compared including a series of hormone concentration in the tissue culture systems. Our continuous efforts were crowned by a very efficient method for achieving up to 30-40% regenerable petioles. Usually on a single petiole several well-separated meristems were induced. After 3-4 weeks of cultivation shoots were developed. The basic media $K_2$ were supplemented with 10g/L saccharose, 10g/L glucose and 10g/L maltose. The following plant hormones were used BAP 1mg/L, TDZ 1mg/L, 2-iP 1mg/L and IAA 0,1 mg/L concentrations. The Petri dishes were kept for 3 weeks in dark at a temperature 22$^{\circ}C$ for 8 hours and 22-24$^{\circ}C$ for 16 hours. The Petri dishes were sealed with Parafilm. The regeneration of the petioles were genotype independent and we were able to regenerate different plum cultivars with almost the same efficiency.

• Korean Journal of Plant Resources
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• v.26 no.3
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• pp.383-388
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• 2013

The research concerned of the regeneration of plants from embryos obtained from anther cultures of ginseng (Panax ginseng C. A. Meyer). The aim was to determine the influence of the regeneration medium on the efficiency of the regeneration process. We conducted to determine the optimum conditions such as cold pretreatment, plant growth regulators and carbon sources on anther culture of P. ginseng. Highest callus formation rate was obtained when flower buds pretreated at $4^{\circ}C$ for 1 day. Among the treated growth regulators with various degrees of concentration in Murashige and Skoog's (MS) medium, 4.53 ${\mu}M$ of 2.4-dichlorophenoxyacetic acid and 4.44 ${\mu}M$ of 6-benzylaminopurine gives the most responsive callus with the frequency of 73.89% and 129.53 g of fresh weight. When we used 3-9% of sucrose and maltose among the different kinds and various concentrations of carbohydrates, callus was formed highest 67.29% in the medium with 3% of sucrose. Shoots induced from callus supplemented with 28.9 ${\mu}M$ of gibberellic acid and rooted in Gamborg's B5 medium supplemented with 14.7 ${\mu}M$ of indole-3-butyric acid.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.2
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• pp.60-66
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• 2014

A control oriented model of the Lean $NO_x$ trap (LNT) was developed to determine the timing of $NO_x$ regeneration. The LNT model consists of $NO_x$ storage and reduction model. Once $NO_x$ is stored ($NO_x$ storage model), at the right timing $NO_x$ should be released and then reduced ($NO_x$ reduction model) with reductants on the catalyst active sites, called regeneration. The $NO_x$ storage model simulates the degree of stored $NO_x$ in the LNT. It is structured by an instantaneous $NO_x$ storage efficiency and the $NO_x$ storage capacity model. The $NO_x$ storge capacity model was modeled to have a Gaussian distribution with a function of exhaust gas temperature. $NO_x$ release and reduction reactions for the $NO_x$ reduction model were modeled as Arrhenius equations. The parameter identification was optimally performed by the data of the bench flow reactor test results at space velocity 50,000/hr, 80,000/hr, and temperature of $250-500^{\circ}C$. The LNT model state, storage fraction indicates the degree of stored $NO_x$ in the LNT and thus, the timing of the regeneration can be determined based on it. For practical purpose, this model will be verified more completely by engine test data which simulate the NEDC transient mode.

• Journal of Animal Environmental Science
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• v.19 no.1
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• pp.55-62
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• 2013

Teff grass is a warm season C4 annual grass that is used for dry hay, silage and haylage. We have developed a high-frequency plant regeneration system for teff grass via callus culture using mature seeds. It was revealed that mature seeds cultured on MS medium supplemented with 2 mg/l 2,4-D, 0.5 g/L proline, 0.5 g/L casamino acid and 3 g/L Gelrite under light condition produced the highest percentage of callus formation (91.9%). Addition of cytokinins (BA) at 0.0~0.5 mg/L to media containing 2 mg/l 2,4-D enhanced callus growth. The most suitable medium for plant regeneration from dehydrated calli was MS agar medium supplemented with 0.1 mg/l NAA, 1 mg/l BA, 0.5 g/L proline, 0.5 g/L casamino acid 3 g/L Gelrite which induced the highest percentage of calli forming shoots (47.0%). The shoots were rooted at the highest rate (100%) when transferred onto 1/2 MS medium and acclimated in greenhouse conditions.

• Journal of the Korean Society of Radiology
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• v.13 no.5
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• pp.811-817
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• 2019

Radiation-therapy causes the adverse radiation effect. It is called osteoradionecrosis. A protein-therapy is carried out in order to cure osteoradionecrosis. The typical method of the protein-therapy is using BMP-2. Considering to bone damage, it is more important that maintains enough to circumstance regeneration for osteoblast differentiation on damage site of bone. Thus, this study is on a tissue regeneration to cure radiation critical damage. I observed that the formation of new regeneration bone by injection of collagen sheet BMP-2 on irradiated mouse. Consequently, I examined new bone formation with collagen sheet BMP-2 on irradiated mouse after 8weeks. Therefore I suggested that using collagen sheet BMP-2 which can be good for new bone regeneration effect on radiation side effect area.

• KEPCO Journal on Electric Power and Energy
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• v.4 no.1
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• pp.33-38
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• 2018

This study applied upgrades to the processes of a 10 MW wet amine $CO_2$ capture pilot plant and conducted performance evaluation. The 10 MW $CO_2$ Capture Pilot Plant is a facility that applies 1/50 of the combustion flue gas produced from a 500 MW coal-fired power plant, and is capable of capturing up to 200 tons of $CO_2$. This study aimed to quantitatively measure efficiency improvements of post-combustion $CO_2$ capture facilities resulting from process upgrades to propose reliable data for the first time in Korea. The key components of the process upgrades involve absorber intercooling, lean/rich amine exchanger efficiency improvements, reboiler steam TVR (Thermal Vapor Recompression), and lean amine MVR (Mechanical Vapor Recompression). The components were sequentially applied to test the energy reduction effect of each component. In addition, the performance evaluation was conducted with the absorber $CO_2$ removal efficiency maintained at the performance evaluation standard value proposed by the IEA-GHG ($CO_2$ removal rate: 90%). The absorbent used in the study was the highly efficient KoSol-5 that was developed by KEPCO (Korea Electric Power Corporation). From the performance evaluation results, it was found that the steam consumption (regeneration energy) for the regeneration of the absorbent decreased by $0.38GJ/tonCO_2$ after applying the process upgrades: from $2.93GJ/ton\;CO_2$ to $2.55GJ/tonCO_2$. This study confirmed the excellent performance of the post-combustion wet $CO_2$ capture process developed by KEPCO Research Institute (KEPRI) within KEPCO, and the process upgrades validated in this study are expected to substantially reduce $CO_2$ capture costs when applied in demonstration $CO_2$ capture plants.

• Journal of Crop Science and Biotechnology
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• v.11 no.2
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• pp.119-126
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• 2008

Since somatic embryogenesis combined with ethylmethane sulfonate(EMS) treatments is the most efficient technique for mutagenesis, the embryogenic capacity of four soybean cultivars was evaluated at different EMS concentrations, treatment times, and preculture durations. Two to 4 mm long immature cotyledons were placed in induction medium after EMS treatment, and the numbers of somatic embryos formed per explant were counted four weeks after culture initiation. We observed genotypic differences in the efficiency of somatic embryogenesis from immature embryos among four cultivars treated with different concentrations of EMS for six hours. Cultivars, Sinpaldalkong 2 and Jack, displayed highly efficient somatic embryogenesis regardless of EMS concentration, whereas very low efficiency or no survival was observed in Jinju 1 and Iksannamulkong cultivars. Preculture duration did not influence the efficiency of somatic embryogenesis. Because Sinpaldalkong 2 exhibited the best somatic embryogenesis, much higher concentrations of EMS were used to test somatic embryo formation under different periods of time in this cultivar. Three and six hour treatments with both 1 and 2 mM EMS yielded higher embryo formation than longer periods of time. Increasing the time with embryos in 2 mM EMS caused a reduction in somatic embryogenesis in Sinpaldalkong 2, but many chlorophyll-deficient soybean variants were identified in the $M_1R_0$ and $M_2R_1$ generations. In addition to Jack, Sinpaldalkong 2 is a good genotype for plant regeneration from EMS-treated immature embryo cultures.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.9
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• pp.589-596
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• 2016

Recently organic flash cycle (OFC) has been proposed which is a vapor power cycle where heat addition occurs with the working fluid remaining in the liquid state. This study proposes a modified OFC with regeneration and carries out thermodynamic performance analysis of the system utilizing low-temperature heat source in the form of sensible energy. Effects of working fluid and flash temperature are systemically investigated on the system performance such as net power production and thermal efficiency. Results show that the net power production has a peak value with respect to the flash temperature but the thermal efficiency increases with the flash temperature. The regenerative system shows higher thermal efficiency compared to the original OFC and improved potential for recovery of low-temperature heat sources.

• Applied Chemistry for Engineering
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• v.8 no.2
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• pp.161-171
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• 1997

Anodic regeneration of PCB enchant and cathodic deposition of copper using electrochemical method has been studied. Cu(I)/Cu(II) concentration ratio as a function of Cu(I) oxidation at the anode was measured from the potential difference between platinum and Ag/AgCl/4M KCl electrodes. Chlorine gas evolution was minimized by maintaining Cu(I) concentration above a specific concentration and using non-porous graphite electrode. Dendritic copper deposition was observed at the cathode and the optimum conditions for Cu deposition was identified as the current density of $360mA/cm^2$, and copper concentration of 12 g/l. Titanium was the most effective cathode material which showed a higher current efficiency and copper recovery. The current efficiency decreased with increasing temperature, but the highest power efficiency was achieved at $50^{\circ}C$.