• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2005년도 가을학술대회
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• pp.154-159
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• 2005

The markers for Environmental Tobacco Smoke(ETS) a.e necessary to obtain, to interpretate and to provide the data of quantitative exposure assessment. The purpose of this research is to evaluate Indoor environment using the concentration of ETS and the correlations between markers(RSP, nicotine, 3-EP) and environmental conditions(smoking density, ventilation rate). The mean ACH(air change per hour) in smoking rooms showed non-compliance with ASHRAE standard value. The concentrations of RSP, 3-EP, nicotine showed log-normal distributions, and became different statistically depending on smoking condition(p<0.01). The geometric mean concentration of RSP in smoking room was 441.7 ${\mu}g/m^3$ that is far exceeded environmental standard(150 ${\mu}g/m^3$). The correlation coefficients between RSP and SI, 3-EP and SI, and Nicotine and SI were 0.67, 0.84, 0.74 respectively. The correlation coefficient between nicotine and 3-EP, Nicotine and RSP, and RSP and 3-EP were 0.76, 0.78, 0.57 respectively.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2000년도 제20회 KOSCO SYMPOSIUM 논문집
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• pp.152-161
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• 2000

The catalytically stabilized combustion of $CH_4$-air mixture on platinum catalyst was investigated numerically using a 2-D boundary layer model with detailed heterogeneous and homogeneous chemistries. The actual surface site density of monolith coated with platinum was decided by the comparison with experimental data. The comparisons were made between results for cases where only heterogeneous chemistry was allowed and both heterogeneous and homogeneous chemistries were allowed. It was found that the homogeneous reaction in the monolith had little effect on the change of temperature profile, methane conversion rate and light off location. The contributions of each reactions related with CO formation were discussed on the surface. The effects of operation conditions such as equivalence ratio, temperature, velocity and pressure at the entrance were studied. In thermal combustor, CO and NOx was produced less than 1 ppm at the exit and the production of $N_{2}O$ was more dominant than that of NO.

• 한국대기환경학회지
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• 제29권1호
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• pp.56-63
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• 2013

This study was aimed at developing and evaluating a diffusive sampling method using a barium hydroxide solution as an absorbent for measuring carbon dioxide ($CO_2$) in ambient air. The collected $CO_2$ concentration was calculated by the change of conductivity resulted in the reaction of $CO_3{^{2-}}$ and $Ba^{2+}$ in aqueous solution. The sampling rate for the diffusive sampler was determined 0.218 mL/min, as obtained from the slope of the linear correlation between the $CO_2$ mass collected by the diffusive sampler and the time-weighted $CO_2$ concentration with the active sampling method. The unexposed blank sampler sealed in aluminium foil-polyethylene laminated packets has remained stable during at least one-month storage period. A good correlation was observed between the diffusive sampler and active sampler with a coefficient of determination of 0.956. This diffusive sampler would be suitable for the indoor $CO_2$ concentration monitoring.

• 한국연소학회지
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• 제7권1호
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• pp.44-51
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• 2002

This paper presents an atomization model for sprays under flash boiling conditions. The atomization is represented by the secondary breakup of a bubble/droplet system, and the breakup is considered as the results of two competing mechanisms, aerodynamic force and bubble growth. The model was applied to predict the atomization of a hollow-cone spray from pintle injector under flash boiling conditions. In the regimes this study considered, sprays are atomized by bubble growth, which produces smaller SMD#s than aerodynamic forces alone. With decreasing ambient pressures, the spray thickness, fuel vaporization rate and vapor radial penetration increases, and the drop size decreases. With increasing the fuel and ambient temperatures to some extent, the effect of flash boiling and air entrainment completely change the spray pattern.

• 환경위생공학
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• 제14권4호
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• pp.93-98
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• 1999

We had investigated combustion properties of rice bran dusts. Decomposition of rice bran dusts with temperature were investigated using DSC and the weight loss according to temperature using TGA in order to find the thermal hazard of rice bran dusts, and the properties of dust explosion in variation of their dust with the same particle size. Using Hartman's dust explosion apparatus which estimate dust explosion by electric ignition after making dust disperse by compressed air, dust explosion experiments have been conducted by varying concentration and size of rice bran dust.According to the results for thermodynamic stability of rice bran dust, there are little change of initiation temperature of heat generation and heating value for used particle size. But initiation temperature of heat generation decreased with high heating rate whereas decomposition heat increased with particle size. Average maximum explosion pressure was $10kgf/cm^2$ for 60/70 mesh and $1.5mg/cm^2$ dust concentration.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 C
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• pp.1765-1767
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• 2001

The shorted-turn sensor for generator's field winding has been developed. The sensor, installed in the generator air-gap, senses the slot leakage flux of field winding and produces a voltage waveform proportional to the rate of change of the flux. For identification of reliability for sensor, a shorted-turn test was performed at the Seoinchon combined cycle power plant on gas turbine generator. This sensor will be used as a detecting of shorted-turn for generator's field winding.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집B
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• pp.328-334
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• 2000

The hybrid catalytic(catalytic+thermal) combustor of a lean methane-air mixture on platinum catalyst was investigated numerically using a 2-D boundary layer model with detailed homogeneous and heterogeneous chemistries. For the more accurate calculations, the actual surface site density of monolith coated with platinum was decided by the comparison with experimental data. It was found that the homogeneous reactions in the monolith had little effect on the change of temperature profile, methane conversion rate and light off location. However, the radicals such as OH and CO were produced rapidly at exit by homogeneous reactions. Thus the homogeneous reactions were important to predict the productions of CO and NOx exactly. In thermal combustor, the production of $N_2O$ was more dominant than that of NO due to the relative important of the reaction $N_2+O(+M){\to}N_2O(+M)$. Finally the production of CO and NOx by amount of methane addition were studied.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2002년도 춘계학술대회논문집
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• pp.83-88
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• 2002

This study is to provide the experimental information and basic data on heat transfer characteristics of horizontal liquid film driven by hot wind. Heat transfer characteristics of the liquid film in the rectangular duct was observed and the change of film temperature was measured. The experiments were carried out for a variety of parameter, such as feed water rate and velocity and temperature of feed air. From the observation and the measurement the general understanding of heat transfer characteristics for liquid film driven by hot wind was provided.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 춘계학술대회 논문집
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• pp.277-280
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• 2008

In this work, the development of the diagnosis algorithm is carried out for identifying health and faulted conditions in three-phase induction motors. The algorithm consists of feature calculation, feature extraction, and feature classification procedures in sequence. Signals for this algorithm are acquired by current and flux sensors simultaneously, the latter is to measure the change of magnetic flux at the air-gap, This work proposes the efficient diagnosis method for induction motors by developing the powerful algorithm. The calculated features show a good linearity according to faults severities. Moreover. the final results show a good classification rate on motor conditions.

• Journal of Advanced Marine Engineering and Technology
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• 제26권1호
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• pp.30-36
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• 2002

This paper presents a developed deep slot squirrel cage induction motor fur the fan. Nearly all of the induction motors consist of two parts, rotor and stator, and the position of rotor is generally inside of stator. However, the rotor of the developed induction motor is located outside of stator. It is believed that the outside rotor type induction motor is suitable for the fan due to its large inertia, that is, it is considered that the change of air flow rate resulting from input power or load fluctuation is reduced. It is considered that the results of this paper can be used for the development of the outside rotor type induction motor.