• Fire Science and Engineering
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• v.15 no.4
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• pp.41-48
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• 2001

Halogen-based fire suppressing agents have been the most effective fire suppressants and widely used for flammable liquid and electric fire. However they have environmental problems causing stratospheric ozone depletion and globe warming. As a substitution of halon, fire suppression system using fine water mist is one of an effective fire suppressant. Suffocating and cooling effects of water mist are increased by the evaporation characteristics because it has droplet size less than 1,000 $\mu{m}$ and very large surface area. In this study, the extinguishing characteristics of fire was measured with changing of water mist droplet size, flow density; discharge pressure, and fire size. As a result, the extinguishing time of pool fire was shortened with the increase of flow density and in case of low flow density less than 0.5$\pm$0.05 ml/$\textrm{cm}^2$ . min, the extinguishing time was shortened with the increase of droplet size. The cycling discharge was effective for $\eta$-heptane pool fire, and total amount of water mist required to extinguish fire was reduced to a quarter compare with continuous discharge.

• Korean Journal of Food Science and Technology
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• v.10 no.4
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• pp.394-397
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• 1978

In vitro digestibility study using pepsin was conducted on round muscle previously treated with papain and the change in the amounts of liberated amino nitrogen was followed during the time course of digestion procedure. The obtained results were summarized as follows. 1. As compared with control, enzyme treatment groups had higher digestibility and curtailed digestion time. 2. All the enzyme treatment groups showed the highest digestibility between 6 and 10 hours in the course of digestion procedure. 3. The amounts of liberated amino nitrogen were increased similarly to digestibility and digestion time. 4. As compared with control, enzyme treatment groups showed considerably higher amounts of liberated amino nitrogen, the liberation rate being the highest between 2 and 8 hours of digestion time.

• The Korean Journal of Malacology
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• v.27 no.4
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• pp.371-376
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• 2011

Digestive enzymatic compositions and activities in digestive diverticula of the three species of bivalves were investigated in this study. Mytilus galloprovincialis, Saxidomus purpuratus and Tegillarca granosa which were collected from southern coast of Korea on November 2010, were used for analysis. Amylase and cellulase occupied approximately 95% of digestive enzymes in digestive diverticula of M. galloprovincialis, S. purpuratus and T. granosa. The amylase and cellulase activities were 2.6 and 0.8 U/mg in M. galloprovincialis, 2.4 and 8.8 U/mg in S. purpuratus and 7.3 and 11.8 U/mg in T. granosa. And protease activities in digestive diverticula of M. galloprovincialis, S. purpuratus and T. granosa showed the lowest values to 0.00019, 0.00028 and 0.00022 U/mg, respectively.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.6
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• pp.635-641
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• 2005

Batch experiments were performed to evaluate the effect of sulfate reduction on methane production and reductive dechlorination, both compete for hydrogen with sulfate reduction. Dechlorination was inhibited by sulfate reduction at lower hydrogen concentration because their threshold values for hydrogen are similar (2 nM). Unlike methane production mainly inhibited transformation of cDCE to ethene, sulfate reduction inhibited the initial dechlorination step, PCE reduction into cDCE as well as cDCE dechlorination. The presence of sulfate eliminated methanogens as hydrogen competitor because of its high threshold value of 10 nM. When sulfate coexisted with PCE, dechlorination efficiency was not affected by the increase of seed concentration as both dechlorination and sulfate reduction were stimulated simultaneously by the increased seeding culture.

• Fire Science and Engineering
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• v.25 no.3
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• pp.51-56
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• 2011

The full-scale experiments are carried out to investigate the fire suppression characteristics of water-based fire fighting systems in a road tunnel. Applied systems are the low-pressure water spray system at 3.5 bar and the high-pressure water mist system at 60 bar. The water flow rate of the high-pressure system is one sixth only of the water spray system. A passenger car and a heptane fuel pan with area of $1.4m^2$ are used as fire sources. A blower system is installed at the tunnel exit to realize the longitudinal ventilation conditions (0.9~3.8 m/s) in the tunnel. Temperatures from the fire source to the down-stream direction are measured by K-type thermocouple trees. The experimental results show that the cooling effect of the high pressure water mist system in the test conditions were equivalent to that of the low pressure water spray system for B-class fire.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.8
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• pp.718-725
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• 2012

Fuel or oil which is leaked into the aircraft engine bay can make a fire when it is contacted to the engine surface of hot temperature. In order to avoid fire, the fire extinguish system should be designed so that the extinguishing agent is quickly injected and its concentration keeps higher in the fire protection region. FAA requires that the extinguishing agent injected within the fire protection region should be sustained longer than 0.5 second on keeping a higher concentration than 6%. For developing a fire protection system satisfying the FAA regulation, numerical and experimental studies for the injection time and the concentration of the extinguishing agent were conducted. These results showed similar trend for the injection time or concentration, but the data acquisition was delayed due to the response of the sensors in the experiment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.4
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• pp.1539-1546
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• 2011

Halon which is one of the typical fire extinguishing agents for special purposes was banned not only to use but to manufacture because it destroys the earth's ozone layer. There have been many efforts to find or create Halon alternatives and Novec1230 which is one of the eco-friendly fire extinguishing agents is nominated. In this paper 6 kinds of valve structures were suggested to apply Novec1230 to fire extinguishing agents for railroad vehicles as Novec1230 needs different valve specifications from Halon and spray shapes and action time were compared and measured. As the results, the extinguishing times of A type and F type valves are 20% faster than the other 4 types, and 178% faster than MIL-DTL-62547(USA). Therefore, they can be suggested to the eco-friendly extinguishing agents and Novec1230.

• The Journal of Internal Korean Medicine
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• v.42 no.6
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• pp.1173-1183
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• 2021

Objectives: This study investigated the clinical characteristics of functional dyspepsia (FD) patients with food retention (FR) in regard to the parameters of cutaneous electrogastrography (EGG), Ryodoraku, and heart rate variability (HRV). Methods: This study reviewed the clinical records of 33 FD patients with FR who filled out the FR Questionnaire for FD (FRQ-FD) and underwent EGG for six months from March 1st, 2021. We summarized the clinical characteristics of FD patients with FR and analyzed the correlation between FRQ-FD score and parameters of EGG, Ryodoraku, and HRV. Results: FRQ-FD scores had a positive correlation with percentage of postprandial bradygastria and negative correlation with power ratio, detected on Channel 2, 3 of EGG. The total average (TA) Ryodoraku score was lower, and the high frequency density (HF) of HRV was higher than the normal value. Conclusions: The results of this study suggest that clinicians can use EGG, Ryodoraku, and HRV to increase the accuracy of diagnosing FR in FD patients.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1B
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• pp.113-118
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• 2006

Cost estimation of an intermittent aerobic digestion technology was carried out in this study. Aeration ratio is one of the most important design factors and it affects installation and power consumption cost. For the purpose, digestion efficiency was fixed at 35% of SS reduction and the reactor type was assumed a 2-chamber sequencing batch reactor (SBR). Installation cost and power consumption cost were evaluated and converted in terms of present value that could reflect the rate of discount and the rate of economic growth. The lower aeration ratio needs higher installation cost but lower power consumption cost. From the point of only installation cost, conventional aerobic digestion is cheaper than intermittent aerobic digestion. But intermittent aerobic digestion is better economical for more than 10 years of estimated service life. The optimal aeration ratio was dependent on the service life and it was lower as the estimated service life increased. For the 45 years as the service life, the optimal aeration ratio was estimated 0.3 and the total cost was 64% of the conventional aerobic digestion.

• The Journal of Internal Korean Medicine
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• v.44 no.4
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• pp.635-644
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• 2023

Objectives: This study analyzed laboratory serum data results before and after patients took herbal medicine to confirm the clinical safety of herbal medicine. In addition, in the event of liver damage, the case was analyzed to confirm the characteristics of liver damage and the possibility of liver damage caused by herbal medicine. Methods: A retrospective chart review of the effects of herbal medicine on liver function in patients diagnosed with functional dyspepsia was conducted. The electronic medical records of 128 patients in a single hospital were reviewed. Results: The statistical analysis revealed a statistically significant decrease in liver function-related laboratory serum data after taking herbal medicine (p<0.05). In addition, among 128 patients, there were two cases of drug-induced liver injury (DILI) (1.56%). Conclusion: Taking herbal medicine prescribed by experts does not significantly affect liver function in patients with functional dyspepsia. Rather, the liver levels of the subjects showed a significant decrease after taking herbal medicine. To support these results, further large-scale multicenter prospective studies are necessary.