Soot particles threshold

Overall, EGR and combustion/injection systems constitute the key factors to comply with the EuroIV standards (applied in January, 2005). The EuroIV step exhibits EuroIII NO and soot particles limits divided by 2. Besides, vehicle s weight is always increasing due to the introduction of new safety systems and equipment. Therefore, pollutants emissions increase and a supplementary effort to reach the normative threshold is to be made. To comply with this target, some evolutions have been introduced, as for example multi-injection or water-cooling of the EGR system. The NO,/particle compromise adjustment remains possible for most of the applications without any after-treatment system like the Diesel particle filter (DPF). 

The Ed distribution exhibits a desorption threshold for the carbon desorbed from the graphite matrix (in atomic form but also in C2 and C3 clusters) around 4.5 mJ/pulse. Therefore, in the Ed interval for the PAHs detection (cf Fig. 3), the underneath carbon matrix should not be destroyed. Supposing a similar structure for a soot matrix, one can achieve a smooth desorption process, without appearance of species artificially produced by the ejection of soot particles fragment during desorption. 

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