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To provide fuel/air ratio quantitative measurements in an S.I engines, a transparent cylinder engine is investigated with the Fuel-Air Ratio Laser Induced Fluorescence (FARLIF) technique. In a homogeneous mixture, the two dimensional distribution for the fuel/air ratio is calibrated and measured during the compression stroke for different equivalence ratios. After spark ignition, the combustion zone and the flame front are visualized by laser sheet LIF. The direct-injection stratified-charge, new concept for gasoline engines is investigated with FARLIF. In the direct injection gasoline engine where the fuel is directly injected into a cylinder and the flow is highly turbulent, two injection timings are used: -early injection (i.e. during the intake stroke) to promote a homogeneous distribution; -late injection during the compression stroke, to generate a ultra-lean stratified charge.

Recent improvement in exhaust after-treatment technologies allows particle removal up to 95% with traps and NOx removal up to 40% with reduction catalyst from diesel exhausts. The efficiency of the technology is mainly based on the rate of regulated pollutant emission reduction but very few information is available in term of health hazard potential which may be related to interactions with several of the hundreds of chemical species present under different phases (liquid, gas, solid). It is therefore necessary to develop useful tools to evaluate the global toxicity of Diesel exhaust. A model of bi-compartimental gas/liquid organotypic culture of lung tissue has been specifically developed and used for continuous in vitro exposure to the exhaust gas of a direct injection 1.9 l turbo-charged engine. Regulated emissions (CO, HC, NOx and particles) were measured in raw exhaust.