• Journal of Energy Engineering
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• v.23 no.2
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• pp.28-34
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• 2014

Automatic transmission fluid (ATF) is used for automatic transmissions in the vehicle as the characterized fluid. Recently, the vehicle manufacture usually guarantee for fluid change over 80000~100000 km mileage or no exchange, but most drivers usually change ATF below every 50000 km driving in Republic of Korea. It can cause to raise environmental contamination by used ATF and increase the cost of driving by frequently ATF change. In this study, we investigate the various physical properties such as flash point, fire point, pour point, kinematic viscosity, cold cranking simulator, total acid number, and metal component concentration for fresh and used ATF after driving (50000 km, 100000 km). The result showed that the total acid number, pour point, Fe, Al and Cu component had increased than fresh ATF, but 2 kind of used oil (50000 km and 100000km) had similar physical values and metal component concentration.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.1
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• pp.1-7
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• 2015

A boiling heat transfer system is used in a variety of industrial processes and applications, such as refrigeration, power generation, heat exchangers, cooling of high-power electronics components, and cooling of nuclear reactors. The critical heat flux (CHF) is the thermal limit during a boiling heat transfer phase change; at the CHF point, the heat transfer is maximized, followed by a drastic degradation beyond the CHF point. Therefore, Enhancement of CHF is essential for economy and safety of heat transfer system. In this study, the CHF and heat transfer coefficient under the pool-boiling state were tested using multi-wall carbon nanotubes (MWCNTs) CM-95 and CM-100. These two types of multi-wall carbon nanotubes have different sizes but the same thermal conductivity. The results showed that the highest CHF increased for both MWCNTs CM-95 and CM-100 at the volume fraction of 0.001%, and that the CHF-increase ratio for MWCNT CM-100 nanofluid with long particles was higher than that for MWCNT CM-95 nanofluid with short particles. Also, at the volume fraction of 0.001%, the MWCNT CM-100 nanofluid indicated a 5.5% higher CHF-increase ratio as well as an approximately 23.87% higher heat-transfer coefficient increase ratio compared with the MWCNT CM-95 nanofluid.

• Journal of the Korean Institute of Gas
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• v.22 no.5
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• pp.31-37
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• 2018

The distrust about chemical plant safety have been increased by occurring the major industrial accidents. Chemical plants have become more and more enlarged and sophisticated to increase production amount and decrease cost. So hazard of industrial accidents also have been increased. In this situation, quantitative risk assessment is activated by introducing OCA(Off-site Consequence Analysis). So it is possible to analyze the objective hazard of chemical plant. Currently OCA focus on the end point of hazardous area by fire/explosion/dispersion. But in this case, it is possible to analyze the industrial accident effect to near the chemical plant but hard to consider the actual hazard by frequency and population density. This study analyzes the validity about application of F-N curve to OCA by compare end point with F-N curve about accident.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.9 s.240
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• pp.988-996
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• 2005

Flame structure and extinction mechanism of counterflow methane/air non-premixed flame diluted with nitrogen are studied by NASA 2.2 s drop tower experiments and two-dimensional numerical simulations with finite rate chemistry and transport properties. Extinction mechanism at low strain rate is examined through the comparison among results of microgravity experiment, 1D and 2D simulations with a finite burner diameter. A two-dimensional simulation in counterflow flame especially with a finite burner diameter is shown to be very important in explaining the importance of multidimensional effects and lateral heat loss in flame extinction, effects that cannot be understood using a one-dimensional flamelet model. Extinction mechanism at low strain rate is quite different from that at high strain rate. Low strain rate flame is extinguished initially at the outer flame edge, the flame shrinks inward, and finally is extinguished at the center. It is clarified from the overall fractional contribution by each term in energy equation to heat release rate that the contribution of radiation fraction with 1D and 2D simulations does not change so much and the overall fractional contribution is decisively attributed to radial conduction ('lateral heat loss'). The experiments by Maruta et at. can be only completely understood if multi-dimensional heat loss effects are considered. It is, as a result, verified that the turning point, which is caused only by pure radiation heat loss, has to be shifted towards much lower global strain rate in microgravity flame.

• Journal of Pharmacopuncture
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• v.20 no.2
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• pp.132-138
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• 2017

Objectives: We report the results of three case studies on the clinical efect of ascending kidney water and descending heart fre (AKDH) pharmacopuncture on patients with Hwa-Byung. Methods: Tis study involved three patients, all female, who had been admitted to a hospital of traditional Korean medicine and had been diagnosed as having Hwa-Byung by using the Hwa-Byung Structure Clinical Interview for DSM-IV. AKDH pharmacopuncture is administered by injecting pharmacopuncture at a specifc acupoint to change from a state of water-fre disharmony to one of water-fre harmony. For our three patients, Hwangyeonhaedoktang (黃連解毒湯) pharmacopuncture was injected at GB21 and GB20 on both sides; a total of 0.4 cc was injected, with 0.1 cc being injected at each point. Fel ursi, Bezora bovis and moschus (BUM) pharmacopuncture was injected at CV17, CV12, and CV6; a total of 0.15 cc was injected, with 0.05 cc being injected at each point. Treatment was done daily. Progress was evaluated using the Hwa-Byung diagnostic interview (HBDIS), beck depression inventory (BDI), and numeric rating scale (NRS) scores. Results: For the frst patient (case 1), after treatment, the HBDIS score was reduced from 44 to 30 points, the BDI score from 37 to 14, and the NRS score from 10 to 7. For the second patient (case 2), after treatment, the HBDIS score was reduced from 41 to 27 points, the BDI score from 13 to 7, and the NRS score from 10 to 5. For the third patient (case 3), after treatment, the HBDIS score was reduced from 42 to 28 points, the BDI score from 12 to 9, and the NRS score from 10 to 4. Conclusion: Ascending kidney water and descending heart fre pharmacopuncture treatment can be efective for improving ascending kidney water and descending heart fre energy and can be used to alleviate Hwa-Byung.

• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.102-108
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• 2009

Fossil power plants firing lower grade coals or equipped with modified system for NOx controls are challenged with maintaining good combustion conditions while maximizing generation and minimizing emissions. In many cases significant derate, availability losses and increase in unburned carbon levels can be attributed to poor combustion conditions as a result of poorly controlled local fuel and air distribution within the boiler furnace. In order to develop a on-line combustion tuning system, field test was conducted at operating power boiler. During the field test the exhaust gases' $O_2$, NOx and CO was monitored by using a spatially distributed monitoring grid located in the boiler's high temperature vestibule and upper convective back-pass region. At these locations, the flue gas flow is still significantly stratified, and air in-leakage is minimal which enables tracing of poor combustion zones to specific burners and over-fire air ports. using these monitored information we can improving combustion at every point within the furnace, therefore the boiler can operate at reduced excess $O_2$ and gas temperature deviation, reduced furnace exit gas temperature levels while also reducing localized hot spots, corrosive gas conditions, slag or clinker formation and UBC. Benefits include improving efficiency, reducing NOx emissions, increasing output and maximizing availability. Discussion concerning the reduction of greenhouse gases is prevalent in the world. When taking a practical approach to addressing this problem, the best way and short-term solution to reduce greenhouse gases on coal-fired power plants is to improve efficiency. From this point of view the real time optimized combustion tuning approach is the most effective and implemented with minimal cost.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.745-748
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• 2008

The past structures were just required bearing capacity to service load, serviceability, and resistance to corrosion. However this point of view has changed after 9.11 terrorism, capacities which can bear impact loading by explosion, and heat by fire happening at the same time, become to be important as a basic condition. The blast resistance capacity of structures is very important part against all over the world is intimidated by terrorism everyday in current point of time. The target of this research is a development of segmented composites and layered structures with high blast resistance using cementitious composites, concrete and FRP composites, which has high tensile strength and ductility, to apply in not only existing facilities but also new ones. Through the improvement of blast resistance, casualties and economic loss can be minimized, and it is possible to diminish the structure collapse and delay the time of structure collapse by thermal effect, impact loading, dynamic loading and high strain.

• Journal of the Korean Solar Energy Society
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• v.29 no.5
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• pp.45-52
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• 2009

Fossil power plants firing lower grade coals or equipped with modified system for $NO_x$ controls are challenged with maintaining good combustion conditions while maximizing generation and minimizing emissions. In many cases significant derate, availability losses and increase in unburned carbon levels can be attributed to poor combustion conditions as a result of poorly controlled local fuel and air distribution within the boiler furnace. In order to develop a on-line combustion tuning system, field test was conducted at operating power boiler. During the field test the exhaust gases' $O_2,\;NO_x$ and CO was monitored by using a spatially distributed monitoring grid located in the boiler's high temperature vestibule and upper convective rear pass region. At these locations, the flue gas flow is still significantly stratified, and air in-leakage is minimal which enables tracing of poor combustion zones to specific burners and over-fire air ports. using these monitored information we can improving combustion at every point within the furnace, therefore the boiler can operate at reduced excess $O_2$ and gas temperature deviation, reduced furnace exit gas temperature levels while also reducing localized hot spots, corrosive gas conditions, slag or clinker formation and UBC. Benefits include improving efficiency, reducing $NO_x$ emissions, increasing output and maximizing availability. Discussion concerning the reduction of greenhouse gases is prevalent in the world. When taking a practical approach to addressing this problem, the best way and short-term solution to reduce greenhouse gases on coal-fired power plants is to improve efficiency. From this point of view the real time optimized combustion tuning approach is the most effective and implemented with minimal cost.

• Applied Chemistry for Engineering
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• v.28 no.6
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• pp.714-719
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• 2017

The contaminated engine oil by fuel can intimidate driver safety due to vehicle problems such as engine abrasion, fire and sudden unintended acceleration. In this study, we investigate various functional properties of the engine oil contaminated with fuel. The test results indicated that the engine oil contaminated with fuel had relatively low values of the flash point, pour point, density, kinematic viscosity and cold cranking simulator. Furthermore, a four ball test suggested that the contaminated engine oil increased wear scar due to the poor lubricity. Moreover, SIMDIST (simulated distillation) using ASTM D2887 was applied to analyze fuel characteristics in an engine oil. The SIMDIST analysis result showed a lower carbon number, and the fuel was detected at an earlier retention time than that of using engine oil in chromatogram. Also, it is possible to quantitatively analyze for fuel contents in the engine oil. The SIMDIST method for the diagnosis of oil conditions can be used whether the fuel was involved or not, instead of analyzing other physical properties that require various analytical instruments, large volumes of oil samples, and long analysis time.

• Journal of Korean Medical classics
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• v.21 no.2
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• pp.151-172
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• 2008

This study searched fundamental basis of four-constitution medicine from the principle of "Yeokgyeong(易經)" that is scientific foundations of Dongmu(東武) Ijema(李濟馬)'s four-constitution medicine based on system of "Yeokgyeong(易經)" and looked into the principle of our-constitution medicine ontologically. That is to say, the translation of five phase(五行) that represented in "Hwangjenaegyeong(黃帝內經)" regulated that substance of five phase is spleen-earth(脾土). But four-constitution medicine mentions the substance as heart-earth(心土) in place of spleen-earth. Because of it's standpoint, the differences on meanings between spleen-earth and heart-earth on the substance of five-phase becomes motive to interpret scientific system of four-constitution medicine fundamental wrongly. For that reason, the research of this title is needed. The results was summarized as follows. First, in ontological view point of structure of four-constitution, five phase is substance and phenomenon, in other words it includes earth of unrevealed substance and wood, fire, metal and water of self-manifestation of existence. Second, in axiological view point, the four-constitution represent principles and contents of four virtues of human nature. And so the innate four virtues ontologically based on four-constitution of heaven. Therefore a human being is endowed innately benevolence, courtesy, justice, intelligence of four virtues. Third, the concept of greater and lesser of Eum(陰, yin) and Yang(陽, yang) in Dongmu(東武)'s four-constitution medicine is four-constitution in "Yeokgyeong(易經)". Greater principle(太極) and four-constitution is a relation of substance and phenomenon. Fourth, the origin and structure of four-constitution medicine includes the structure and principle of natural philosophical Eumyang and four-constitution, the human-centric theory and sciences of human nature and natural laws and medical experience of traditional oriental medicine and medical principle.