• Journal of the Korean Applied Science and Technology
• /
• v.33 no.2
• /
• pp.374-384
• /
• 2016

Concern about air pollution is gradually rising up in domestic and foreign, automotive and fuel researchers are trying to reduce vehicle exhaust emissions, through a lot of approaches, which consist of new engine design and innovative after-treatment systems, using clean (eco-friendly alternative) fuels and fuel quality improvement. This research is proceeding by two main issues : exhaust emissions and PM particle emissions of gasoline vehicle. Exhaust emissions, non-regulated emissions and PM (particulate matter) particles of automotive are causing many problems which ambient pollution and harmful effects on the human body. The main particulate fraction of automotive exhaust emissions consists of small particles. Because of their small size, inhaled particles can easily penetrate deep into the lungs. The rough surfaces of these particles make it easier for them to combine with other toxins in the environment. Thus, the hazards of particle inhalation are increased. Based on the oxygenated fuel additive types (MTBE, Bio-ETBE, Bio-ethanol, Bio-butanol), this paper discussed the influence of oxygen contents on gasoline vehicle exhaust emissions, non-regulated emissions and nano-particle emissions. Also, this paper assessed exhaust emission characteristics at 2 type test modes. The test modes were FTP-75 and HWFET. All measurement items be verified less than the value of regulated emissions. It could be known difference increase and decrease by each measurement item depending on increase the oxygen contents.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.30 no.10 s.253
• /
• pp.973-981
• /
• 2006

Recently there is an increasing interest in particulate matter emission because of new emission regulations, health awareness and environmental problems. It requires to improve particulate measurement techniques as well as to reduce soot emissions from combustion systems. As mentioned above, it is demanded that reduction techniques together with measurement techniques of exhausted particulate matters in combustion systems such as vehicles. However, measurement techniques of particulate matters should be prior to reduction techniques of that because it is able to know an increase and a decrease of exhausted particulate matters when measured particulate matters. Therefore, in this study, we report the measurement of soot primary-particle size using time-resolved laser induced incandescence (TIRE-LII) technique in laminar ethylene diffusion flame. As an optical method, laser induced incandescence is one of well known methods to get information for spatial and temporal soot volume fraction and soot primary particle size. Furthermore, TIRE-LII is able to measure soot primary particle size that is decided to solve the decay ate of signal S $(t_1)$ and S $(t_2)$ at two detection time. In laminar ethylene diffusion flame, visual flame height is 40 mm from burner tip and measurement points are height of 15, 20, 27.5, 30 mm above burner tip along radial direction. As increasing the height of the flame from burne. tip, primary particle size was increased to HAB(Height Above Burner tip)=20mm, and then decreased from HAB=27.5 mm to 30 mm. This results show the growth and oxidation processes for soot particles formed by combustion.

• Fire Science and Engineering
• /
• v.26 no.4
• /
• pp.70-76
• /
• 2012

This paper deal with vehicle fire caused by damage of diesel particulate filter (DPF) on diesel passenger vehicles. In order to reduce particulate matters included exhaust gases, a DPF in the exhaust system were installed diesel vehicles. A DPF was broken by excessively trapped particulate matters, regeneration error with a malfunction of ECU and defect of suction system such as swirl valve. If the DPF was broken, hot exhaust gases was released to the bottom of vehicle and released hot exhaust gases lead to occur the fire through combustible materials around the exhaust system. When a fire happened in the diesel vehicle caused by damage of DPF, silicate inorganic compounds were attached to the exhaust ventilation pipe and muffler. The silicate inorganic compounds were created by DPF combustion consisting of raw material ceramics. If the silicate inorganic compounds attached to the tail pipe in the diesel passenger vehicles, its fire cause will be assumed damage of DPF.

• Proceedings of the KSME Conference
• /
• 2001.06d
• /
• pp.802-806
• /
• 2001

Diesel particulate trap is the most reliable system to reduce the particulate matters from diesel engine. Filter is the core component of DPF and ceramic monolith type is dominantly used, which is expensive and fragile relatively at thermal shock. Porous metal filter, which has superior thermal characteristics and low cost, was tested in order to analyze the regeneration performance by using with ferrocene additive. This filter showed the 72% filtration efficiency, additives itself diminished 48% of PM from engine out emission, and final PM reduction ratio of 89% was achieved by DPF system with D-13 test mode.

• Proceedings of the KSR Conference
• /
• 2007.11a
• /
• pp.994-999
• /
• 2007

The particulate matters emitted by diesel locomotives cause serious air pollution in stations and railroad. There have been various attempt to reduce the air pollution from diesel bus or trucks. However, the air pollution from the diesel locomotives has been out of control because there has not any adaptable technology. In this study, a diesel particulate filter was developed and applied to the diesel locomotives. A 3,000 horsepower large-scale locomotive and a 1,500 horsepower middle-scale locomotive were used for the test of the filter. The particulate matter emissions before and after the treatment was monitored by a scanning mobility particle sizer and a dust monitor. As a result, it was observed that the particulate matters could be successfully removed from the emission gases by using the filter.

• Journal of Korean Elementary Science Education
• /
• v.23 no.2
• /
• pp.116-122
• /
• 2004

The purpose of this study is to investigate effects of computer animations using particulate model in elementary science classes related to air pressure. To do those, four classes of 5th grade in an elementary school located in a city were selected. As an experiment group, two classes were applied the teaching materials of computer animations developed for this study based on particulate model. The other classes as a control group were not applied these materials in science classes. The total scores of experiment group in which computer animation using particulate model was applied in science classes are higher than those of the control group in the conception test. Only in one conception related to high and low atmospheric air pressure, the scores of the two groups are not significantly different at 0.05 significance level.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.13 no.4
• /
• pp.9-17
• /
• 1994

It is well recognized recently that ultrasonic technique is one of the most widely used methods of nondestructive evaluation to characterize material properties of nonconventional engineering materials. Therefore it is very important to understand physical phenomenon on propagation behavior of elastic wave in these materials, which is directly associated with ultrasonic signals in the test. In this study, the theoretical analysis on multi-scattering of harmonic elastic wave due to the particulate with interface between matrix and fiber in metal matrix composites(MMCs) was done on the basis of Lax's quasi-crystalline approximation and extinction theorem. SiC particulate (SiCp) reinforced A16061-T6 composite material was chosen for this analysis. From this analysis, frequency dependences of phase velocity and amplitude attenuation of effective plane wave due to the change of volume fraction of SiC particulate were clearly found. It was also shown that the interface condition between matrix and fiber in MMCs gives a direct effect on the variation of phase velocity of plane wave in MMCs.

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2003.05b
• /
• pp.181-183
• /
• 2003

대기를 통해 물질과 에너지가 순환한다는 것은 이미 잘 알려진 지구화학적 과정이다. 즉, 대기를 통해 자연적 혹은 인위적인 원인으로부터 배출되는 여러 가지 물질들이 인근지역이나 때로는 광범위한 지역으로 이동되고, 태양으로부터 오는 빛을 가스나 입자상 물질들이 흡수, 산란시키거나, 일부 미세한 입자상 물질들은 구름의 응결핵으로 작용함으로써 지구의 에너지 균형에도 관여한다. 에너지나 물질의 순환이라는 측면에 더하여 가스나 입자상 물질들은 대기 중에 머무는 동안 인체나 주변 생태계에도 영향을 미치게 된다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2002.04a
• /
• pp.157-158
• /
• 2002

다단임팩터(cascade impactor)는 대기환경 연구에 있어 입자상물질의 물리 화학적 분석에 유용하게 사용되고 있는 입자상물질 포집장치이다. 다단임팩터의 각 단은 외벽(stage wall), 가속노즐판(acceleration nozzle plate)과 충돌판(impaction plate)으로 구성되며 충돌판에는 입자상물질의 포집을 위하여 테플론 필터, 알루미늄 필터 등을 장착하게 되어 있다. (중략)

• Journal of Korean Society of Environmental Engineers
• /
• v.35 no.5
• /
• pp.312-320
• /
• 2013

Particulates in drinking water distribution system (DWDS) are mostly influenced by internal corrosion of metal pipes and sediment in pipelines due to the solution of this effect is limited. The particle size, component and properties of compounds for particulates in distributed water are different and the difference of these characteristics will be occurred by the kind of facilities, pipe condition, external factors and supply system etc. In this study, conducting the investigation of water quality in DWDS researches with particulates in the water. Monitoring sites were each water supply reservoir and the end of water supply area in DWDS. To collect particulate material at each sampling site, $47{\phi}$ glass microfiber filter type GF/C was performed using a filtration. Substances that the effect of the turbidity in the water according to particulate suspended solids and inorganic materials is due to the increasing particulates in the end of DWDS were increased. The result of compounds analysis by using X-ray diffraction (XRD) were Goethite (${\alpha}$-FeOOH), Magnetite ($Fe_3O_4$) in the end of DWDS and Quartz ($SiO_2$), Yeelimite ($Ca_4Al_6O_{12}SO_4$) at the effluent of waterworks and reservoirs. There were differences the compounds and sediments in the releasing or remaining water distribution facilities.