• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.2 no.4
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• pp.71-102
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• 2007

There were many comprehensive analyses conducted within the existing research activities wherein factors affecting technology progress including investment in R&D vis-${\Box}$-vis their influences act as the determinants of TFP. Note, however, that there were few comprehensive analysis in the industrial research performed regarding the impact of the economy of scale as it affects TFP; most of these research studies dealt with the analysis of the non -parametric Malmquist productivity index or used the stochastic frontier production function models. No comprehensive analysis on the impacts of individual independent variables affecting TFP was performed. Therefore, this study obtained the TFP increase rate of each industry by analyzing the factors of the existing growth accounting equation and comprehensively analyzed the TFP determinants by constructing a comprehensive analysis model considering the investment in R&D and economy of scale (smallness by industry) as the influencers of TFP by industry. First, for the TFP increase rate of the 15 industries as a whole, the annual average increase rate for 1993${\sim}$ 1997 was approximately 3.8% only; during 1999${\sim}$ 2000 following the foreign exchange crisis, however, the annual increase rate rose to approximately 7.8%. By industry, the annual average increase rate of TFP between 1993 and 2000 stood at 11.6%, the highest in the electrical and electronic equipment manufacturing business and IT manufacturing sector. In contrast, a -0.4% increase rate was recorded in the furniture and other product manufacturing sectors. In the case of the service industry, the TFP increase rate was 7.3% in the transportation, warehousing, and communication sectors. This is much higher than the 2.9% posted in the electricity, water, and gas sectors and -3.7% recorded in the wholesale, food, and hotel businesses. The results of the comprehensive analysis conducted on the determinants of TFP showed that the correlations between R&D and TFP in general were positive (+) correlations whose significance has yet to be validated; in the model where the self-employed and unpaid family workers were used as proxy variables indicating the smallness of industry out of the total number of workers, however, significant negative (-) correlations were noted. On the other hand, the estimation factors of variables surrogating the smallness of scale in each industry showed that a consistently high "smallness of scale" in an industry means a decrease in the increase rate of TFP in the same industry.

• Economic and Environmental Geology
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• v.48 no.1
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• pp.25-39
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• 2015

$CO_2$ geological storage plays an important role in reduction of greenhouse gas emissions, but there is a lack of research for CCS demonstration. To achieve the goal of CCS, storing $CO_2$ safely and permanently in underground geological formations, it is essential to understand the characteristics of them, such as total storage capacity, stability, etc. and establish an injection strategy. We perform the impedance inversion for the seismic data acquired from the Ulleung Basin in 2012. To review the possibility of $CO_2$ storage, we also construct porosity models and extract attributes of the prospects from the seismic data. To improve the quality of seismic data, amplitude preserved processing methods, SWD(Shallow Water Demultiple), SRME(Surface Related Multiple Elimination) and Radon Demultiple, are applied. Three well log data are also analysed, and the log correlations of each well are 0.648, 0.574 and 0.342, respectively. All wells are used in building the low-frequency model to generate more robust initial model. Simultaneous pre-stack inversion is performed on all of the 2D profiles and inverted P-impedance, S-impedance and Vp/Vs ratio are generated from the inversion process. With the porosity profiles generated from the seismic inversion process, the porous and non-porous zones can be identified for the purpose of the $CO_2$ sequestration initiative. More detailed characterization of the geological storage and the simulation of $CO_2$ migration might be an essential for the CCS demonstration.

• Economic and Environmental Geology
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• v.54 no.1
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• pp.105-115
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• 2021

The geological CO2 sequestration in underground geological formation such as deep saline aquifers and depleted hydrocarbon reservoirs is one of the most promising options for reducing the atmospheric CO2 emissions. The process in geological CO2 sequestration involves injection of supercritical CO2 (scCO2) into porous media saturated with pore water and initiates CO2 flooding with immiscible displacement. The CO2 migration and distribution, and, consequently, the displacement efficiency is governed by the interaction of fluids. Especially, the viscous force and capillary force are controlled by geological formation conditions and injection conditions. This study aimed to estimate the effects of surfactant on interfacial tension between the immiscible fluids, scCO2 and porewater, under high pressure and high temperature conditions by using a pair of proxy fluids under standard conditions through pendant drop method. It also aimed to observe migration and distribution patterns of the immiscible fluids and estimate the effects of surfactant concentrations on the displacement efficiency of scCO2. Micromodel experiments were conducted by applying n-hexane and deionized water as proxy fluids for scCO2 and porewater. In order to quantitatively analyze the immiscible displacement phenomena by n-hexane injection in pore network, the images of migration and distribution pattern of the two fluids are acquired through a imaging system. The experimental results revealed that the addition of surfactants sharply reduces the interfacial tension between hexane and deionized water at low concentrations and approaches a constant value as the concentration increases. Also it was found that, by directly affecting the flow path of the flooding fluid at the pore scale in the porous medium, the surfactant showed the identical effect on the displacement efficiency of n-hexane at equilibrium state. The experimental observation results could provide important fundamental information on immiscible displacement of fluids in porous media and suggest the potential to improve the displacement efficiency of scCO2 by using surfactants.

• Tuberculosis and Respiratory Diseases
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• v.45 no.1
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• pp.140-152
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• 1998

Background: Prone position improves oxygenation in patients with ARDS probably by reducing shunt Reduction of shunt in prone position is thought to be effected by lowering of the critical opening pressure (COP) of the dorsal lung because the pleural pressure becomes less positive in prone position compared to supine position. It can then be assumed that prone position would bring about greater improvement in oxygenation when PEEP applied in supine position is just beneath COP than when PEEP is above COP. Hemodynamically, prone position is expected to attenuate the lifting of cardiac fossa induced by PEEP. Based on these backgrounds, we investigated whether the effect of prone position on oxygenation differs in magnitude according to the level of PEEP applied in supine position, and whether impaired cardiac output in supine position by PEEP can be restored in prone position. Methods: In seven mongrel dogs, $PaO_2/F_1O_2$(P/F) was measured in supine position and at prone position 30 min. Cardiac output (CO), stroke volume (SV), pulse rate (PR), and pulmonary artery occlusion pressure (PAOP) were measured in supine position, at prone position 5 min, and at prone position 30 min. After ARDS was established with warmed saline lavage(P/F ratio $134{\pm}72$ mm Hg), inflection point was measured by constant flow method($6.6{\pm}1.4cm$ $H_2O$), and the above variables were measured in supine and prone positions under the application of Low PEEP($5.0{\pm}1.2cm$ $H_2O$), and Optimal PEEP($9.0{\pm}1.2cm$ $H_2O$)(2 cm $H_2O$ below and above the inflection point, respectively) consecutively. Results : P/F ratio in supine position was $195{\pm}112$ mm Hg at Low PEEP and $466{\pm}63$ mm Hg at Optimal PEEP(p=0.003). Net increase of P/F ratio at prone position 30 min, however, was far greater at Low PEEP($205{\pm}90$ mm Hg) than at Optimal PEEP($33{\pm}33$ mm Hg)(p=0.009). Compared to CO in supine position at Optimal PEEP($2.4{\pm}0.5$ L/min), CO in prone improved to $3.4{\pm}0.6$ L/min at prone position 5 min (p=0.0180) and $3.6{\pm}0.7$ L/min at prone position 30 min (p=0.0180). Improvement in CO was attributable to the increase in SV: $14{\pm}2$ ml in supine position, $20{\pm}2$ ml at prone position 5 min (p=0.0180), and $21{\pm}2$ ml at prone position 30 min (p=0.0180), but not to change in PR or PAOP. When the dogs were turned to supine position again, MAP ($92{\pm}23$ mm Hg, p=0.009), CO ($2.4{\pm}0.5$ L/min, p=0.0277) and SV ($14{\pm}1$ ml, p=0.0277) were all decreased compared to prone position 30 min. Conclusion: Prone position in a dog with saline-lavaged acute lung injury appeared to augment the effect of relatively low PEEP on oxygenation, and also attenuate the adverse hemodynamic effect of relatively high PEEP. These findings suggest that a PEEP lower than Optimal PEEP can be adopted in prone position to achieve the goal of alveolar recruitment in ARDS avoiding the hemodynamic complications of a higher PEEP at the same time.

• Korean Journal of Food Science and Technology
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• v.52 no.5
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• pp.560-563
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• 2020

Cold plasma has been applied to improve quality of food product; however, studies on its effects on microbial and physicochemical qualities of rice noodles are rarely conducted. In this study, changes in the quality characteristics of rice noodles treated by cold plasma were determined. Cold plasma was generated in a square-shaped plastic container (250 W, 15 kHz, ambient air), and dielectric barrier discharge plasma treatments were applied to rice noodle samples for 0, 10, or 20 min. Rice noodles inoculated with either Bacillus cereus or Escherichia coli O157:H7 were subjected to plasma treatment for 20 min, and the approximate bacterial count reduction were 4.10 and 2.75 log CFU/g, respectively. The Hunter color values of the sample were increased after cold plasma treatment. Peroxide values and thiobarbituric acid reactive substance (TBARS) were increased with an increase in cold plasma treatment time. Futhermore, lipid oxidation was enhanced. Although further studies are warranted to evaluate changes in chemical qualities, such as lipid oxidation of rice noodles, induced by cold plasma, the results suggest that cold plasma can improve the microbial and physical qualities of rice noodles.

• Applied Chemistry for Engineering
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• v.5 no.5
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• pp.808-818
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• 1994

Effects of ceria additive on the activity and thermal aging behavior of supported Ru catalysts were investigated using Ru/${\gamma}$-$Al_2O_3$and Ru/$CeO_2$-${\gamma}$-$Al_2O_3$. The catalysts were characterized by $^{129}Xe$-NMR and $H_2$ chemisorption. The cataltic activity for conversion of CO, HC and $NO_x$ was measured using simulated automobile engine exhausts under lean, rich and stoichiometric conditions. For both fresh and aged catalysts, Ru/$CeO_2$-${\gamma}$-$Al_2O_3$ was more active than Ru/${\gamma}$-$Al_2O_3$ for all three pollutants. Results of $^{129}Xe$-NMR and $H_2$ chemisorption indicated that sintering of Ru particles occurred to the same extent for both catalysts during the thermal aging process. After thermal aging at 673K, however, the catalytic activity of the aged Ru/$CeO_2$-${\gamma}$-$Al_2O_3$ was substantially higher than that of the fresh one, while the activity of Ru/${\gamma}$-$Al_2O_3$ decreased after the thermal aging. This finding may suggest new active sites were created during the thermal aging, probably in the vicinity of the interface between Ru and Ce. For more quantitative investigation of the effect of a cation such as Ce on the thermal aging of Ru metal particles, Ru catalysts supported on cation-exchanged Y-zeolites were used as the model catalysts. The results indicated that when Ba, Ca, La, Y or Ce was used for the cation exchange, the exchanged cation did not affect the thermal aging behavior of Ru in Y-zeolite, as evidenced by $^{129}Xe$-NMR and EXAFS.

• Journal of Chest Surgery
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• v.32 no.7
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• pp.637-647
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• 1999

Background: Ischemia-reperfusion injury is one of the major contributing causes of early graft failure in lung transplantation. It has been suggested that triiodothyronine (T3) may ameliorate ischemia-reperfusion injury to various organs in vivo and in vitro. Predicting its beneficial effect for ischemic lung injury, we set out to demonstrate it by administering T3 into the in situ canine ischemia-reperfusion model. Material and Method: Sixteen adult mongrel dogs were randomly allocated into group A and B. T3 $(3.6\mug/kg)$ was administered before the initiation of single lung ischemia in group B, whereas the same amount of saline was administered in group A. Ischemia was induced in the left lung by clamping the left hilum for 100 minutes. After reperfusion, various hemodynamic parameters and blood gases were analyzed for 4 hours while intermittently clamping the right hilum in order to allow observation of the injured left lung function. Result: Arterial oxygen partial pressure $(PaO_2)$ decreased 30 minutes after reperfusion and recovered gradually thereafter in both groups. In group B the decrease of $PaO_2$ was less marked than in group A. The recovery of $PaO_2$ was faster in group B than in group A. The differences between the two groups were statistically significant from 30 minutes after reperfusion $(125\pm34$ mmHg and $252\pm44$ mmHg, p<0.05) until the end of the experiment $(178\pm42$mmHg and $330\pm37$ mmHg, p<0.05). The differences in the arterial carbon dioxide pressure, airway pressure and lung compliance showed no statistical significance. The malondialdehyde (MDA) level, measured from the tissue obtained 240 minutes after reperfusion, was lower in group B $(0.40\pm0.04\mu$M) than in group A $(0.53\pm0.05\mu$M, p<0.05). The ATP level of group B $(0.69\pm0.07\mu$M/g) was significantly higher than that of group A $(0.48\pm0.07\mu$M/g, p<0.05). The microscopic exami nation revealed varying degrees of injury such as perivascular neutrophil infiltration, capillary hemorrhage and interstitial congestion. There were no differences in the microscopic findings between the two groups. CONCLUSION T3 has beneficial effects on the ischemic canine lung injury including preservation of oxygenation capacity, less production of lipid peroxidation products and a higher level of tissue ATP. These results suggest that T3 is effective in pulmonary allograft preservation.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.12
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• pp.803-812
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• 2014

This study assesses the strategy and performance of Eco-industrial Park (EIP) initiative implemented by Korea Industrial Complex Corporation (KICOX) with the support of Ministry of Trade, Industry and Energy (MOTIE), Korea since 2005 to 2013 and recommends future directions. After the concept of EIP based on industrial symbiosis (IS) is introduced, the background and implementation procedure of the EIP initiative are described. Then, economic and environmental achievement was assessed. During the project periods (2005-2013), 449 industrial symbiosis project were explored, among which 296 projects have been implemented. Among (Of these 296 projects,) them, 244 projects have been completed in which 118 projects have been commercialized which shows 48% commercialization rate of the completed projects. Through these commercialized projects, around 311.1 billion won/year of economic benefits and reduction of waste by-products of 828,113 tons/year, wastewater of 215,517 tons/year, reduction in energy consumption of 250,475 toe/year and GHG emission reduction of 1,107,189 $tCO_2/year$ were achieved. This results confirmed that EIP initiative based on industrial symbiosis can enhance eco-efficiency of industrial parks and harmonize economy and environment. However, there are obstacles like absence of interagency coordination and cooperation, laws and institutional barriers, increased demand for local governments, funding for project investment. Thus, to utilize EIP initiative as a strategic tool for competiveness and environmental management of industrial parks, it needs intergovernmental collaboration and interdisciplinary approach to lower barrier in implementation.

• Nuclear Engineering and Technology
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• v.28 no.2
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• pp.118-128
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• 1996

The lattice parameters of stoichiometric $UO_2$ and $U_{1-y}Er_{y}O_2$ in the range of y=0.01 to y =0.33 were determined with use of X-ray diffraction data. Oxygen potentials have been measured by means of a thermogravimetric method in the range of 1200~$1500^{\circ}C$ and $10^{-14}$ $\leq$ $Po_2$ $\leq$ $10^{-3}$ for pure $UO_2$ and $U_{1-y}Er_{y}O_{2{\pm}x}$ solid solutions with y=0.02, y=0.06 and y=0.20, respectively. Their oxygen partial pressures were maintained by controlling $CO_2$/CO mixture atmosphere, and the $Po_2$ values corresponding to x of $U_{1-y}Er_{y}O_{2{\pm}x}$ solid solutions were measured with an electrolyte oxygen sensor. The lattice parameter decreases linearly with an increase in the erbium content. The change of the lattice parameter can be expressed in a linear equation of y as a($\AA$) =5.4695-0.220y for 0 $\leq$y$\leq$0.33. The experimental coefficient of y -0.220 in $U_{1-y}Er_{y}O_2$ was an intermediate value between the calculated values -0.273 and -0.156 in the case of $U^{5+}$ and $U^{6+}$, respectively. The (equation omitted) has been found to undergo abrupt increase in the range of -360 to -270 kJ/mole for y=0.06 and -320 to -220 H/mole for y=0.20, respectively, in the temperature range of 1200-$1500^{\circ}C$. (equation omitted) increases with erbium content, but the effect of the dopant for x =0.01 is less significant than that for stoichiometry. The oxygen potentials for $UO_2$ and $U_{0.98}Er_{0.02}O_{2+x}$ can be approximately represented by the $U^{5+}$/$U^{4+}$ model but those for y$\geq$ 0.06 in $U_{1-y}Er_{y}O_{2{\pm}x}$ solid solutions cannot be interpreted by the mean uranium valence model.

• Korean Journal of Plant Tissue Culture
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• v.25 no.4
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• pp.257-261
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• 1998

The repeated subcultures of in vitro plant materials in wasabi became highly vitrified and the capacity for multiple shoot formation from the vitrified plant materials was very low. In order to improve the quality of in vitro propagated planting materials, the experiments were carried out using culture vessels capped with membrane filter(MF). When vitrified shoots were cultured on MS medium with 0.2mg/L BA in the vessels with MF or without MF for 60 days, the shoots in the vessels with MF did not vitrified. In contrast, the shoots grown in the vessels without MF vitrified at 65%. The stomates of vitrified leaves were circular and inflated, whereas those of normal leaves acclimatizated in the vessels with MF were ovate in shape. The hardened shoots were also cultured on MS media without sucrose containing 0.01mg/L IBA in vessels with(photoautotrophic culture) or without(control) MF. Sucrose was necessary for survival of the in vitro plantlets in the vessels without MF. After 20 days of culture, the shoots in the vessels without MF on the sucrose-free media turned yellow and died. But the shoots in the vessels with MF in the sucrose-free media produced a lot of roots. When shoots were cultured on MS medium with 2% sucrose containing 0.01mg/L IBA in the vessels with(photomixotrophic culture) or without(heterotrophic culture) MF, best growth occured in photomixotrophic culture.