• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.5
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• pp.277-282
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• 2015

During hot and humid weather, air-conditioners consume a large amount of electricity due to the large amount of latent heat. Simultaneous usage of a dehumidifier may reduce latent heat and reduce electricity consumption. In this study, dehumidification performance was measured for a small-sized dehumidification rotor made of inorganic fiber impregnated with metallic silicate within a constant temperature and humidity chamber. Regeneration to dehumidification depends on ratio, rotor speed, room temperature, regeneration temperature, room relative humidity and frontal velocity to the rotor. Results demonstrate an optimum area ratio (1/2), rotor speed (1.0 rpm), and regeneration temperature ($100^{\circ}C$) to achieve a dehumidification rate of 0.0581 kg/s. As the area ratio increases, the optimum rotation speed and the optimum regeneration temperature also increase. Above the optimum rotor speed, incomplete regeneration reduces dehumidification. Above the optimum regeneration temperature, increased temperature variation between regeneration and dehumidification reduces dehumidification. Dehumidification rate also increases with an increase of relative humidity, dehumidification temperature and flow velocity into the rotor.

• BMB Reports
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• v.55 no.8
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• pp.401-406
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• 2022

Ahnak, a large protein first identified as an inhibitor of TGF-β signaling in human neuroblastoma, was recently shown to promote TGF-β in some cancers. The TGF-β signaling pathway regulates cell growth, various biological functions, and cancer growth and metastasis. In this study, we used Ahnak knockout (KO) mice that underwent a 70% partial hepatectomy (PH) to investigate the function of Ahnak in TGF-β signaling during liver regeneration. At the indicated time points after PH, we analyzed the mRNA and protein expression of the TGF -β/Smad signaling pathway and cell cycle-related factors, evaluated the cell cycle through proliferating cell nuclear antigen (PCNA) immunostaining, analyzed the mitotic index by hematoxylin and eosin staining. We also measured the ratio of liver tissue weight to body weight. Activation of TGF-β signaling was confirmed by analyzing the levels of phospho-Smad 2 and 3 in the liver at the indicated time points after PH and was lower in Ahnak KO mice than in WT mice. The expression levels of cyclin B1, D1, and E1; proteins in the Rb/E2F transcriptional pathway, which regulates the cell cycle; and the numbers of PCNA-positive cells were increased in Ahnak KO mice and showed tendencies opposite that of TGF-β expression. During postoperative regeneration, the liver weight to body weight ratio tended to increase faster in Ahnak KO mice. However, 7 days after PH, both groups of mice showed similar rates of regeneration, following which their active regeneration stopped. Analysis of hepatocytes undergoing mitosis showed that there were more mitotic cells in Ahnak KO mice, consistent with the weight ratio. Our findings suggest that Ahnak enhances TGF-β signaling during postoperative liver regeneration, resulting in cell cycle disruption; this highlights a novel role of Ahnak in liver regeneration. These results provide new insight into liver regeneration and potential treatment targets for liver diseases that require surgical treatment.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.7
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• pp.521-528
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• 2007

The desiccant rotor is the most essential component of desiccant cooling system, but its design relies on manufacturer's experience and principles are not yet clear in spite of a lot of theoretical/experimental work published. The mathematical modeling of desiccant rotor needs solution of coupled partial differential equations of heat and mass transfer. In this study, numerical program is developed and validated using a real desiccant rotor. The calculation results are in reasonable agreement with the experimental data and other available numerical results. Optimization of desiccant rotor on the condition of low regeneration temperature are investigated. The optimal rotor speed at which the process outlet humidity becomes minimized, shows same as that of the system optimization. Compared to high regeneration temperature, broad is the range of optimal speed of low regeneration temperature. Systematic analysis on the optimal area ratio of regeneration to dehumidification section has also been conducted.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.2
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• pp.93-100
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• 2002

Comparison results of callus formation ratio from seed explants, callus sizes, regeneration ratios from callus and regeneration efficiency [calculated by following formular; callus formation ratio(%) ${\times}$ regeneration ratio(%)/100] for 27 ochardgrass (Dactylis glomerata L.)varieties imported and Hapsung 2 developed in Korea are as follows; 1. Among ochardgrass varieties showing more than 50% callus formation ratios, the descending order of callus formation ratio after bedding the seed explants for 4 weeks was 93M>Sparta> Pizza>Condor>Lidaglo>Glorus>Hapsung 2>Frode. 2. The callus sizes after bedding for 4 weeks were in the range of $\Phi$ 0.43cm~4.2cm in which there was 10 times size difference between the largest one and the smallest one but most of them were between ${\Phi}2.5cm~4cm$. 3. The regeneration ratio from callus among varieties were in the range of 0~36% and descending order of the upper 6 varieties was Plano>Akimidori>Justus>Lidacta>Currie>Hall mark. 4. The regeneration efficiency which is calculated by the ratios of regeneration from seed explant numbers was between 0 to 17.4% among which Justus showed the highest value in the 4-week treatment. 5. The correlation between callus formation ratios and the callus sizes, callus formation ratios and regeneration efficiency, and callus sizes and regeneration efficiency were r=0.5765, r=0.6365 and r=0.6246, respectively in 4-week callus and all the correlations were significant on the 1% level. 6. In 6-week callus, the descending order callus formation ratios from seed explants fur the best 6 varieties was Condor>Sparta>93 M>Justus>Potomac>Lidaglo>Frode. 7. The callus sizes formed were between ${\Phi}1.5~5.7cm$ in which Sparta, the largest one of ${\Phi}5.7cm$ was five times larger than the smallest one. The callus size of the control variety, Hapsung 2 was ${\Phi}3.8cm$, which belonged to a larger size. 8. Regeneration ratio showed a great deviation among varieties from 6-week old calli by showing from 0% to 100% in which all the calli were regenerated in Piano while no callus was regenerated in Juno. 9. The range of regeneration efficiency was between 0~28% among varieties in which the values from 6-week callus treatment were larger than those from 4-week callus treatment. Especially, the value of Potomac in 6-week was 3 times larger than that in 4-week. 10. The correlation between callus formation ratios and the callus sizes, callus formation ratios and regeneration efficiency, and callus sizes and regeneration efficiency were r=0.5369, r=0.6683 and r=0.5937. respectively in 6-week callus, and all the correlations were significant on the 1% level.

• Environmental Engineering Research
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• v.22 no.2
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• pp.169-174
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• 2017

Vacuum swing adsorption (VSA) is a promising treatment method for volatile organic compounds (VOCs). This study focuses on a VSA process for regenerating activated carbon spent with VOCs, and then investigates its adsorption capacities. Toluene was selected as the test VOC molecule, and the VSA regeneration experiments results were compared to the thermal swing adsorption process. Cyclic adsorption-desorption experiments were performed using a lab-scale apparatus with commercial activated carbon (Samchully Co.). The VSA regeneration was performed in air (0.5 L/min) at 363.15 K and 13,332 Pa. The comparative results depicted that in terms of VSA regeneration, it was found that after the fifth regeneration, about a 90% regeneration ratio was maintained. These experiments thus confirm that the VSA regeneration process has good recovery while operating at low temperatures (363.15 K) and 13,332 Pa.

• Journal of Periodontal and Implant Science
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• v.36 no.3
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• pp.653-659
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• 2006

Oral malodor may cause a significant social or psychological handicap to those suffering from it. Oral malodor has been correlated with the concentration of volatile sulfur compounds (VSC) produced in the oral cavity. Specific bacteria identified in the production of VSC have been reported and many of these bacteria are commonly suspected periodontal pathogens. The aim of this study was to estimate the change of the VSC concentration after periodontal treatment, Twenty subjects with probing depth $(PD)\;{\geq}5mm$ (experimental group) and 20 subjects with PD<5mm (control group) participated. VSC concentration measurement was made with gas chromatography. VSC concentration was measured at pre-treatment, 2 weeks after scaling and 1 month after periodontal treatment(root planning and flap operation). Maximum probing depth and bleeding on probing(BOP) were also examed at pretreatment and 1 month after periodontal treatment, The conclusions were as follow: 1. In the experimental group VSC concentration and CH3SH/H2S ratio were higher than control group. (p<0.05) 2. Both VSC concentration and CH3SH/H2S ratio showed decrease after periodontal treatment, But only CH3SH/H2S ratio after 1 month periodontal treatment was statistically significantly different from pre-treatment. (p<0.05) 3. CH3SH/H2S ratio tended to be on increase according to maximum probing depth and bleeding on probing. Periodontal disease could be a factor that caused oral malodor and oral malodor could be decreased after periodontal treatment.

• Journal of Korean Dental Science
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• v.10 no.2
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• pp.53-59
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• 2017

Purpose: The objective of the present article is to determine whether there are differences in vertical enlargement ratio among various sites within both jaws in a panoramic radiograph. Materials and Methods: Two hundred and seventy-threeimplant sites in panoramic radiographs were evaluated by two observers. Magnification ratios at various sites in both jaws were calculated and compared with each other. Result: The average vertical enlargement ratio in the panoramic radiograph was 1.264 and this value was larger than original ratio 1.250. Although vertical magnification ratio of maxillary molar area was higher than that of mandibular molar area, every group showed similar magnification ratio in clinical respect. Conclusion: Vertical magnification ratio of the maxillary molar area is statistically higher than that of the mandibular molar area in the panoramic radiograph, but it is clinically negligible.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2008.05a
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• pp.90-92
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• 2008

Environmental matters are one of key issues of today's world. At this point, advanced countries are proposing and planning various kinds of policies for sustainable communities. Space designers in those countries are more concerned with regeneration or slow development than development and innovation. As the new government of Korea was started in 2008, it announced 'design Korea project' as key agenda for national competitiveness. But it seems that they are focusing on development of new town than the concept of preservation or regeneration on which most advanced countries put their bases. In these regards, this research starts with the idea that environmental factor in space design is very important and it is directly connected with human survival. With this idea, the researching team created experimental space titled 'regeneration' as one of eco-friendly education program. The team aimed at building up or 'designing one man space-one to one ratio' in deserted place with recycled stuffs. With the idea of 'regeneration' in space, the researcher aims at awakening the sense of environment and putting it into practice in daily living.

• BMB Reports
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• v.55 no.12
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• pp.633-638
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• 2022

Liver regeneration is a well-known systemic homeostatic phenomenon. The N⁶-methyladenosine (m⁶A) modification pathway has been associated with liver regeneration and hepatocellular carcinoma. m⁶A methyltransferases, such as methyltransferase 3 (METTL3) and methyltransferase 14 (METTL14), are involved in the hepatocyte-specific-regenerative pathway. To illustrate the role of METTL14, secreted from non-parenchymal liver cells, in the initiation phase of liver regeneration, we performed 70% partial hepatectomy (PH) in Mettl14 heterozygous (HET) and wild-type (WT) mice. Next, we analyzed the ratio of liver weight to body weight and the expression of mitogenic stimulators derived from non-parenchymal liver cells. Furthermore, we evaluated the expression of cell cycle-related genes and the hepatocyte proliferation rate via MKI67-immunostaining. During regeneration after PH, the weight ratio was lower in Mettl14 HET mice compared to WT mice. The expressions of hepatocyte growth factor (HGF) and tumor necrosis factor (TNF)-α, mitogens derived from non-parenchymal liver cells that stimulate the cell cycle, as well as the expressions of cyclin B1 and D1, which regulate the cell cycle, and the number of MKI67-positive cells, which indicate proliferative hepatocyte in the late G1-M phase, were significantly reduced in Mettl14 HET mice 72 h after PH. Our findings demonstrate that global Mettl14 mutation may interrupt the homeostasis of liver regeneration after an acute injury like PH by restraining certain mitogens, such as HGF and TNF-α, derived from sinusoidal endothelial cells, stellate cells, and Kupffer cells. These results provide new insights into the role of METTL14 in the clinical treatment strategies of liver disease.

• Journal of The Korean Society of Grassland and Forage Science
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• v.23 no.1
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• pp.59-64
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• 2003

Comparisons of callus formation ratios from seed explants, callus sizes, regeneration ratios from callus and regeneration efficiency for 4 orchardgrass (Dactylis glomerata L.) varieties (Three were developed in Korea and one was imported from foreign nation) are as follows; Jangbeol 102 (67.0%) has the highest callus formation ratio in 4 weeks incubated callus after bedding the seed explants, but Potomac (68.4%) has the highest ratio in 6-week callus. Potomac (3.91cm) has the highest callus size in 4-week callus, but Jangbeol 101 (4.32cm) has the highest size in 6-week callus. Jangbeol 101 (17.7%) has the highest plant regeneration ratio in 4-week callus, but Potomac (37.4%) has the highest ratio in f-week callus. Jangbeol 102 (11.5%) has the highest plant regeneration efficiency in 4-week callus, but Potomac (25.6%) has the highest efficiency in 6-week callus.