• Korean Journal of Plant Tissue Culture
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• v.25 no.5
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• pp.347-351
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• 1998

Plant regeneration via organogenesis from leaf and stipule explants of micropropagated shoots of strawberry (Fragaria $\times$ ananassa cv. Suhong) was achieved. Leaf and stipule explants were detached from shoot-tip cultured shoots and cultured on MS medium with various combinations of BA and NAA under light or dark condition. Shoot regeneration from leaf explant was observed after 3 weeks in culture and was good at the high ratio of BA and NAA among various combination treatments. The highest shoot regeneration frequency from leaf explants was obtained with 1.0 mg/L BA and 0.1 mg/L NAA, in which 31.1% shoot regeneration frequency(1.7 shoots per leaf explant) was yielded. In case of stipule explants, shoot regeneration was largely affected by plant growth regulators during incubation under dark condition for initial 4 weeks but not under continuous light condition. The combination treatment with 2.0 mg/L BA and 0.1 mg/L NAA showed the most excellent shoot regeneration from stipule explants, where 44.4% regeneration frequency(4.0 shoots per explants) obtained. Regenerated shoots were rooted on MS medium with 0.1 mg/L NAA after shoot elongation, and the plantlets regenerated were transferred to soil mixtures with vermiculite and perlite for acclimation.

• Journal of Environmental Science International
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• v.31 no.9
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• pp.743-755
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• 2022

This study aims to review the differences in urban regeneration independently implemented by the government (Ministry of Land, Infrastructure, and Transport, MOLIT) and Seoul based on related laws and ordinances, and to draw out the implications of Korean urban regeneration's directions. The results are as follows. First, Seoul has constantly responded to the revision of the Urban Regeneration Act by adjusting and specifying the contents of ordinances, and especially, there have been efforts to enhance regional characteristics suitably for the circumstances of Seoul. Second, in the urban regeneration of Seoul, the budgets including the matching ratio of national and local subsidies shall be changed according to the standards of the MOLIT in changing designating places after the selection of the urban regeneration by the ministry, and this procedure and these implementation methods cause confusion to Seoul and local governments. Third, there were differences in the results of comparing the budgets and support methods of the "Gaggum Housing Project" of Seoul and "New Deal Housing Repair Project" of the MOLIT, which caused conflicts due to the differences in the project implementation and support standards, and the arbitrary interpretation of the guidelines. Although the urban regeneration greatly contributed to the revelation and conservation of regional characteristics, it might be necessary to establish systems that can enhance citizens' awareness and compensate the efficient contents needed for each region in the future.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.9
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• pp.43-48
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• 2012

This paper presents an iterative single-frequency continuous-wave signal-based I/Q regeneration method for improving image-rejection performance of multi-port junction-based direct receivers (MPDRs). This paper analyzes I/Q regeneration in MPDRs as I/Q mismatch compensation for direct conversion receivers. Based on the analysis, this paper evaluates the accuracy of I/Q regeneration in terms of the image-rejection ratio (IRR). The proposed method improves the IRR performance more than 20 dB compared to existing I/Q regeneration methods. Simulation results show that MPDRs using the proposed method can achieve an IRR of more than 70 dB, and that the bit error rate performances are almost the same as those of conventional coherent demodulators, even in fading channels.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.4
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• pp.68-76
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• 2006

The minimization of maximum DPF wall temperature and the fast Light-off during regeneration are the targets for the high durability of the DPF system and the high efficiency of regeneration. In order to predict transient thermal response of DPF, one-channel numerical modeling has been adopted. The effect of the ratio of length to diameter(L/D), cell density, the amount of soot loading on temporal thermal response and regeneration characteristics has been numerically investigated under two different running conditions: city driving mode and high speed mode. The results indicate that the maximum wall temperature of DPF increase with increasing 'L/D' in 'High speed mode'. For 'City driving mode', the maximum wall temperature decreases with increasing 'L/D' in the range of $'L/D{\geq}0.6'$. The maximum temperature decreases with increasing cell density because heat conduction and heat capacity are increased. It is also found that the effect of amount of soot loading on light-off time is negligible.

• Journal of Environmental Health Sciences
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• v.27 no.4
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• pp.9-14
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• 2001

This study was performed to develop the modified FGD(Flue Gas Desulfurization) process which can eliminate the possibility of generating secondary pollutants. Limestone was regenerated by adding ammonium hydroxide and carbon dioxide, and reusing it as a absorbent in FGD gypsum Process. A series of the new or modified FGD process which include desulfurization and regeneration limestone from CaSO$_3$. 1/2H20 and CaSO4 . 2H2O, were carried out under various experimental conditions. The results showed that the optimum injection ratio for regeneration of limestone was 0.3 ml/min of CO2 flow rate, 2 ml of NH4OH per 0.01 M of regent grade CaSO4 . 2H20O and the optimum regeneration temperature was 50. The increaser was the number of times of limestone regeneration, the faster was the breakthrough point of desulfurization at the desulfurination process which the regenerated limestone was used. Then the efficiency of desulrurization was decreased. This study can be confirmed the possibility for reuse of regenerated limestone due to the similarity of desulfurization characteries both reagent grade calcium carbonate and regenerated calcium carbonate. Finally, it appeared that the new technology using regenerated 1imestone can be applied to the FGD process.

• Solar Energy
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• v.20 no.1
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• pp.91-96
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• 2000

This study was performed to find out how much experimental factors influence on regeneration performance in a solar air conditioning system. The experimental apparatus was set up in a climate-controlled chamber where temperature and humidity could be kept constant. In order. to investigate factors' influence on the regeneration performance of the solar air conditioning system, the model experiment was done using the 600mm $\times$ 600mm black painted aluminum regenerator. The design and analysis of experiment were done by the design of experiments, especially the table of orthogonal arrays. In order to find out how much experimental factors influence on regeneration performance, the table of orthogonal arrays $L_8(2^7)$ was used. According to the results, it was found that the most influential factor to affect regeneration performance was the concentration of LiCl solution. The next influential factors were a solar radiation, an air velocity, and the temperature of LiCl solution in order.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.4
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• pp.82-87
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• 2013

A study on desorption and regeneration characteristics for silver ions adsorbed onto crab shells was carried out by means of Nitric acid soultion which was selected as the best desorbing agent. Desorption efficiency for silver ions was the highest as about 96% at the 1.0M of Nitric acid concentration. Also, silver ions was almost desorbed below 1.0 of S/L(mg/mL) ratio which is defined as the ratio of adding amount of adsorbent and volume of desorbing agent and most of desorption process was completed within 60min. And removal efficiency of reused crab shells for silver ions was maintained as about 92% until the 2nd cycle.

• Clean Technology
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• v.22 no.2
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• pp.82-88
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• 2016

The loss of activity by coke is an important cause of catalyst deactivation during industrial operation. In this study, hydrogen ratio of reaction condition, which has influenced on coke formation over Pt-Sn catalyst, and regeneration of catalysts activity by coke burning, Pt sintering of coke burning as coke contents, effects of coke formation and deactivation with different Sn contents were confirmed. Pt-Sn-K catalyst supported on θ-alumina and γ-alumina was prepared progressively. Activity of regenerated catalyst for propane dehydrogenation was compared with fresh catalyst by coke burning, after propane dehydrogenation was carried out with different hydrogen ratio at 620 ℃ on fresh catalyst. Regenerated catalyst’s physical characterization such as BET, coke analysis and XRD was investigated. Through catalytic activity test and characterization, Sn contents of catalyst and hydrogen ratio in feed stream could affect coke formation on catalyst surface. Excessive coke makes loss of activity and Pt sintering during air regeneration process.

• The Journal of the Korean dental association
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• v.48 no.1
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• pp.45-55
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• 2010

Purpose: The aim of this study was to evaluate 1 year cumulative survival rate of implants placed on augmented sinus using Osteon$^{(R)}$, bone graft material and to assess height of the grafted material radiographically. Material and Methods: 10 maxillary sinuses were augmented in 10 patients and 25 implant fixtures were installed simultaneously or after 6 months healing period. The height of the sinus graft material was measured using panoramic images immediately after augmentation and up to 19 months subsequently. Changes in the height of the sinus graft material were calculated with respect to implant length and original sinus wall height. Results: The cumulative survival rate was 100% in all 25 implants. Additionally, normal healing process without any complication was observed in all patients. The mean crown/Implant ratio was 1.25. The mean marginal bone loss was 0.95mm and the mean resorption rate of Osteon$^{(R)}$ was 0.05mm/month. The fastest resorption site of Osteon$^{(R)}$ is the first molar area. The grafted material was well maintained in sinus and decreased slightly over 1 year. Conclusion: In conclusion, It can be suggested that Osteon$^{(R)}$ may have predictable result when it was used as a grafting material for sinus floor augmentation.

• Korean Chemical Engineering Research
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• v.48 no.6
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• pp.679-683
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• 2010

In this study, calcination temperature dependence of TS-1 catalyst was investigated in the hydroxylation of phenol with hydrogen peroxide during the regeneration of catalyst. Catalyst was regenerated 5 times by calcining at $550^{\circ}C$ and $700^{\circ}C$, respectively. When the catalyst was regenerated at $550^{\circ}C$ after 5th regeneration phenol conversion was decreased from 22.9% to 15.1% and at $700^{\circ}C$ after 5th regeneration phenol conversion was decreased from 22.9% to 18.8%. For formation ratio of catechol/hydroquinone was increased from 1.28 to 1.45 after 5th regeneration at $550^{\circ}C$, and from 1.28 to 1.20 after 5th regeneration at $700^{\circ}C$. The main reasons for deactivation of the catalyst were suggested by analyzing chemical/physical properties with XRD, UV-vis spectra, $N_2$ adsorption/desorption and TGA, and evaluating the catalytic activity such as phenol conversion and product selectivity.