• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.1
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• pp.221-232
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• 1993

In this study, the period for stabilization in the case of recycling leachate was compared and analyzed with the case of non-cycle type, using lysimeters filled with municipal organic refuse. The lysimeters were operated with various detention time. In addition, the degree of stabilization was estimated by the way of measuring the quantity of gas from landfills. As the results, the recycle of leachate, which was modified as the neutral level of pH, accelerated the biological decomposition of organics with the raped growth of anaerobic bacteria in the system, and reduced the period for the stabilization. In the case of BOD and COD in leachate, COD. which had been originality similar to BOD, had increased more rapidly than BOD as time lapsed. Moreover, the quantity of gas from the recycle reactor was larger than from the non-cycle reactor. The shorter the detention time of leachate gas, the larger the quantity of gas produced in the lysimeters.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.19-24
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• 2003

This paper is to research the heat transfer characteristic in copper-water variable conductance heat pipes(VCHP) with a non-condensable gas and gas reservoir. The heat transfer characteristics in the VCHP have not yet been studied much researches. VCHP are used in many applications. These applications range from thermal control of components and systems on satellites, to precise temperature calibration duties, conventional electronics temperature control and thermal diodes. The practical use of VCHP is a simple way to control the temperature of satellites. As the quantity of NCG was increased, there was an increase in the saturation vapor temperatures. As the input heat has loaded from 90 W to 110 W, the difference of the evaporator surface is lower than $10^{\circ}C$.

• Journal of the Korean Institute of Gas
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• v.14 no.3
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• pp.26-34
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• 2010

KOGAS, established in 1983 by law to ensure stable gas supply to the public, is responsible for the wholesale distribution to 30 city gas companies that deal with the retail distribution of natural gas in their geographic areas. The gas imported by KOGAS is measured by checking the level difference of LNG shipped in tankers before and after unloading. The analysis of gas composition is essential because the imported gas price is determined by its calorific value. The turbine meter is widely used for measuring the gas sold to city gas companies. Unlike the metering system for power plants, there is no gas chromatograph since the custody transfer of gas to the city gas companies is not billed by calorific value, but by volume basis. The gas quantity that a city gas company has bought from KOGAS is not equal to the quantity that the company sold to its customers. There have been some discrepancies between the wholesale gas meter readouts and retail ones due to some inherent errors of meters and some operational issues of the meters. This paper investigates the controversies regarding the real quantity of gas between distributors and consumers. It will discus and suggest desirable policies, both technically and economically, in order to solve the discrepancies of gas measurement.

• Transactions of the Korean Society of Mechanical Engineers
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• v.11 no.1
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• pp.177-188
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• 1987

A compute program based on the minimization of total Gibbs' free energy and enthalpy balance was developed to calculate the chemical equilibrium composition and adiabatic flame temperature, especially stressed on NO and CO concentration of Heavy oil. Twenty four components of combustion gases which would be produced from the combustion of Heavy oil were chosen and utilized for the products composition analysis of competing combustion reaction. As the results, following conclusions were turned out; (1) Maximum adiabatic flame temperature was found around to be 2900K, when the stoichiometric air ratio was 0.8. (2) Maximum NO quantity in adiabatic process was occurred when supplied air quantity was around 120% of theoretical air requirement. (3) NO and CO quantities were increased with combustion gas temperature at constant stoichiometric air ratio. (4) At constant temperature of combustion gas, NO quantity was increased and Co quantity was decreased with supplied air quantity.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.2
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• pp.57-63
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• 2000

This paper deals with a study on combustion and emission characteristics of a direct injection diesel engine dual fueled with natural gas. Dual fuelling systems tend to emit high unburned fuel especially at low load, resulting in a decreased thermal efficiency. This is because natural gas-air mixtures are too lean for flame to propagate under low load conditions. Suction air quantity and injection timing controls are very useful to improve emissions and thermal efficiency at low load.

• Journal of Korean Institute of Fire Investigation
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• v.11 no.1
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• pp.59-65
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• 2008

Among the various cases of fire accident, gas accident which is roost essential have a lot of forms and causes. The quantity consumed of gas is increasing because of increment of gas-using families and variations of gas machinery. The quantity consumed of gas in 2007 was 35078 tons and the average rate of increasement was 9.4%. The amount of gas accident was on the peak at 1995 when 557 accidents occurred in a year. In 2007, 123 gas accidents was occurred and the average rate of diminution was 11.5%. Accidents by LP gas took 80% of the whole accident and city gas and high pressure gas took 20%. In case of LP gas, accidents were usually occurred because of lack of blocking after the removal of gas machinery and moveable butane burner. Especially, the accidents cause by carelessness of a provider is increasing. Gas accidents which generate damage of human life and property, are caused by users' carelessness, providers' carelessness, inferiority of structure and old products. In this thesis, We will classify the gas accidents. Furthermore through the classification of accidents by forms, causes and regions, this thesis going to be a reference to understand and prevent the accidents.

• Journal of the Korean Institute of Gas
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• v.23 no.4
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• pp.28-39
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• 2019

In this paper is image characteristics of main gas can be a basic data for the identification of the type of leaking gas and the estimation of the emission quantity in OGI(Optical Gas Image) technology. The purpose of this research is to observe the differences of leaking gas images of the two important hydrocarbons of methane and propane in the industry. We fabricated a wind shield of quartz-based with infrared-permeable properties was prepared and methane and propane were simultaneous emission and then photographed with an infrared OGI camera and we are analyzed it. We have a stable image with windbreak of quartz-based minimizes the effect of wind. As a result of analyzing the image of two hydrocarbons with a leakage gas reference value of 1 L/min, an easily recognizable distances by OGI camera were 6 m for methane and 9 m for propane. In the distances range of 1 to 10 m between the infrared camera and the leaking gas point, the gas plume size of the propane gas was larger and clear than that of the methane gas plume. Compared with the number of points in the image, propane was 3.8 times more than methane.

• Journal of the Korea Safety Management & Science
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• v.17 no.2
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• pp.229-234
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• 2015

Depending on the living styles, the types of energy consumed by households have changed, and the consumption has increased rapidly. Consequently, those have led to environmental issues, such as exhaustion of energy and the climate changes. As one of solutions to such issues, energy efficiency can be approached. Therefore, in this study, the gas water heater(115S type Rheem products) that made in Germany and obtain hot water using gas as a heat source is selected. a $1.0m^3$ water tank with a 6kW electronic heater is installed and a water temperature and pressure is maintain constantly also thermometer is injected. Two of gas meter, one of pressure regulator and three of time measurement devices are installed in a combustion facility and fuelling facility with a magnet valve so it can observe and record combustion reactions. Quantity of hot water that heated by boiler is recorded using a quantity measurement tank, and have been heated by the boiler have been to record and measure the amount and utilized the data acquired through measurement of all factors that are applied to acquire hot water in order to calculate the use rate of final energy. In conclusion, this researcher drew the economic strong points of the hot water generated by gas.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.4
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• pp.43-50
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• 2002

In the present study, reduction of harmful exhaust gas in a diesel engine using stratified injection system of dual fuel (diesel fuel and methanol) was tried. The nozzle and fuel injection pump of conventional injection system were remodeled to inject dual fuel in order from the same injector. The quantity of each fuel was controlled by micrometers, which were mounted at rack of injection pumps. The injection ratio of dual fuel was certificated by volumetric ratio in injection quantity test. Cylinder pressure and exhaust gas were measured and analyzed under various supply condition of duel fuel. We confirmed that combustion of dual fuel was performed successful1y by using modified injection system in a D.I. diesel. Soot and NOx are simultaneously reduced by stratified injection without large deterioration of thermal efficiency, but THC and CO are relatively increased.

• Journal of the Korean Ceramic Society
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• v.37 no.1
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• pp.44-49
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• 2000

Silicon nitride powders, were synthesized by the vapor phase reaction using SiH4-NH3 gaseous mixture. The reaction temperature, ratio of NH3 to SiH4 gas and the overall gas quantity were varied. The synthesized powders were characterized using X-ray, TEM, FT-IR and EA. The synthesized silicon nitride powders were in amorphous state, and the average particle size was about 100nm. TEM analysis revealed that the particle size decreased with increasing reaction temperature and gas flow quantity. As-received amorphous powders were annealed in nitrogen atmosphere at 140$0^{\circ}C$ for 2h, then the powders were completely crystallized at 0.2 ratio of NH3 to SiH4.