• Journal of Fisheries and Marine Sciences Education
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• v.29 no.2
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• pp.586-592
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• 2017

This study analyzed the effect of four control factors, RPM, load, EGR rate and cooling water temperature on the exhaust emissions of the small DI diesel engine. The amount of NOx and smoke emissions were measured through experiments for three levels of four control factors according to orthogonal array table, and the effect of four factors on NOx and smoke emissions was analyzed quantitatively. The main results obtained in this study are summarized as follows: 1. RPM, load and EGR rate have a great influence on NOx and smoke emissions, and the effect of cooling water temperature is negligible. 2. As RPM and load increases NOx emission increases and decreases sharply as the EGR rate increases. 3. Smoke emission decreases or increases randomly according to RPM and load, but increases sharply in proportion to the EGR rate. 4. EGR rate has the greatest effect on NOx and smoke emissions by more than 60% of contribution to variance, especially in the case of NOx emission, EGR rate represents a significant result even under the confidence level of 99% on ANOVA.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.5
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• pp.888-896
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• 2011

A white smoke hand grenade, KM8 is used to make smoke screen in order to provide visual field interceptions or signals. The grenade fails when its time to emit smoke is longer than the specified emission time so that the smoke concentration becomes lighter. This paper considered failure in smoke emission time, and evaluated its storage lifetime. The main objective of this paper is to modify the present specification limits of smoke emission time for the efficient process control in manufacturing, through analyzing effect of its specification change on the storage lifetime, based on the lifetime evaluation results. Accelerated degradation test was performed and then failure in smoke emission time was reproduced from the test. And estimated storage lifetimes from the accelerated test results was compared to evaluated lifetimes of grenades using the ASRP data. Past process testing results of the grenade in manufacturing were analyzed in this paper. Then, each storage lifetime for the specifications, ${\pm}3$ and ${\pm}5$ in seconds, extended from the current specification in manufacturing were estimated using the past testing results, and compared to one another.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.3
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• pp.85-91
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• 2003

In this study, the potential possibility of oxygenated fuel such as Methyl tertiary butyl ether (MTBE) was investigated for the sake of exhausted smoke reduction from diesel engine. MTBE has been used as a fuel additive blended into unleaded gasoline to improve octane number, but the study of application for diesel engine was incomplete. Because MTBE includes oxygen content approximately 18%, it is a kind of oxygenated fuel that the smoke emission of MTBE is reduced remarkably compared with commercial diesel fuel. But, the NOx emission of MTBE blended fuel is increased compared with commercial diesel fuel. And, it was tried to analyze not only total hydrocarbon but individual hydrocarbon components from $C_1$ to $C_6$ in exhaust gas using gas chromatography to seek the reason for remarkable reduction of smoke emission. Individual hydrocarbons($C_1$~$C_6$) as well as total hydrocarbon of oxygenated fuel are reduced remarkably compared with diesel fuel. And, the effects of exhaust gas recirculation(EGR) on the characteristics of NOx emission has been investigated, too. It was found that simultaneous reduction of smoke and NOx was achieved with oxygenated fuel and cooled EGR method.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.3
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• pp.8-17
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• 2002

In this study, it was tried to analyze not only total hydrocarbon but individual hydrocarbon components from C$_1$to C$\sub$6/ in exhaust gas using gas chromatography to seek the reason fur remarkable differences of smoke emission of diesel fuel, esterfied rice bran oil and blended fuel(esterfied rice bran oil 20vo1-% + diesel fuel 80vo1-%). Individual hydrocarbons(C$_1$ ∼C$\sub$6/) as well as total hydrocarbon of esterfied rice bran oil is reduced remarkably compared with diesel fuel. Although smoke emission of esterfied rice bran oil reduced remarkably compared with commercial diesel fuel, NOx emission of esterfied rice bran oil and blended fuel was increased slightly at high loads and speeds. And, it was tried to reduced NOx emission of them by exhaust gas recirculation(EGR) method. Simultaneous reduction of smoke and NOx emission was achieved with the combination of esterfied rice bran oil and EGR method in consequence.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.2
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• pp.215-223
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• 2012

A violet smoke hand grenade(KM18) is used to generate signals. The grenade is considered to fail when its smoke emission time is longer than the specified one so that its smoke concentration becomes lighter. Accelerated degradation test for the grenade was performed, and then failure in smoke emission time was reproduced from the test. Stress for the degradation test was selected as temperature/humidity from the pre-test results. Degraded data of emission time from the accelerated test were analyzed through applying a distibution-based degradation model. Then, Peck Model was applied to predict the storage life under field conditions. In addition, the predicted storage life was compared with that of ASRP(Ammunition Stockpile Reliability Program).

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.4
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• pp.59-67
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• 2000

Recently the world is faced with the very serious problems related to the increasing use of the conventional petroleum fuels. THe air pollutions in big cities were also occurred by the exhaust emissions from automobiles. many researchers have been attracted various oxygenated fuels as an alternative fuel and a renewable fuel for the measure of these problems. In this study the effect of oxygen in fuel on the exhaust gas emissions has been investigated with oxygenated fuels as an alternative fuel for diesel engine. The exhaust gas emission were investigated by comparing with that of the diesel fuel. The vegetable fuel oil such as soybean oil gives lower smoke level than that with diesel fuel. Furthermore the smoke emission is more affected by the oxygen content in fuel than by the fuel viscosity. This study concluded that the fuels including oxygen might be a good measure to reduce smoke in diesel engine because the oxygen strongly influenced the combustion process.

• Journal of Power System Engineering
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• v.6 no.1
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• pp.27-35
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• 2002

In this paper, the effect of oxygen component in fuel on the exhaust emissions has been investigated for direct injection diesel engine. It is tested to estimate change of engine performance and exhaust emission characteristics for the commercial diesel fuel and oxygenate blended fuel which has four kinds of mixed ratio. And, the effects of exhaust gas recirculation(EGR) on the characteristics of NOx emission and brake specific fuel consumption rate have been investigated. Dimethyl carbonate(DMC) contains oxygen component 53.3% in itself, and it is a kind of effective oxygenated fuel of carbonate group that the smoke emission of DMC is reduced remarkably in comparison with commercial diesel fuel, that is, it can supply oxygen component sufficiently at higher loads and speeds in diesel engine. It was found that simultaneous reduction of smoke and NOx was achieved with oxygenated fuel and EGR method.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.7
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• pp.2421-2429
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• 1996

The objective of this research is to apply effect of the pre-mixed combustion quantity and smoke emission in diesel engine. According as air fuel ratio is increased, emission of smoke concentration is linearly reduced. As Injection timing is advanced, smoke concentration is remarkably reduced. It is considered to be the primary cause of the increase in the premixed combustible mixture during long ignition delay period with advancing injection timing. Smoke is increased with increasing engine speed, so it is considered to be the primary cause of the increase of the mass of fuel injected. Smoke is decreased according to the increase of methanol volume ratio. It is considered that the primary cause of the increase in the quantity of pre-mixed combustion.

• Journal of the Korean Society of Safety
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• v.26 no.4
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• pp.111-119
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• 2011

This study was designed to provide basic data applicable to fire investigation through consideration of combustion products and propose vulnerability of combustibles through analysis of $CO_2$ emission. In order to achieve these research objectives, characteristics of combustion products such as smoke release rate of each part(raw leaves, branches and barks), $CO_2$ emission and ash production were considered targeting on 6 oak species(Quercus variabilis Blume, Quercus aliena Blume, Quercus serrata, Quercus mongolica Fisch, Quercus dentata Sapling and Quercus acutissima) using cone calorimeter and smoke density tester. As a result, it was found that raw leaves release smoke more relatively than branches and barks, when they burn, and that Quercus variabilis Blume has the highest smoke density. Also, Quercus acutissima released CO and $CO_2$ which are respectively, 6.67 times and 1.43 times more than Quercus variabilis Blume with low $CO_2$ emission. In addition, branches released CO and $CO_2$ more relatively. There was a big difference in ash production among raw leaves(3.1 g), branches(10.5 g) and barks(16.43 g). It was identified that Quercus serrata produces ashes which are nearly 9.95 times more than Quercus variabilis Blume. It demonstrates that Quercus serrata contains relatively higher minerals and that Quercus variabilis Blume can leave lots of traces like stain and carbonization, as it releases smoke a lot and it's difficult to predict visibility, when a forest fire breaks out in its community area. It is also considered that smoke particles containing oil in the air leave strain on the surface of a tree, and that CO and $CO_2$ emission increases, when crown fire to burn branches breaks out.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.7
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• pp.84-89
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• 2014

Not only the emission regulation of on-road vehicle engine, but also emission regulation of off-road engine have been reinforced. It is the reason of wide application of emission reduction technology for off-road engines. In this study, optimization of engine parameters (Injector hole number, Injection timing and EGR rate) for reduction of NOx and smoke emissions were conducted by using the analysis of sensitivity and S/N ratio of Taguchi method(DOE). As results, this paper shows optimum value of the parameters for NOx and smoke emission reduction. From the result of reproducibility verification, it is final that the prediction value of NOx and smoke has the error of below 10%. Consequently, the method and results of this study will be used for quantitative reference to EGR control mapping in next study.