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The major sources of noise pollution, especially in urban areas are caused by traffic noise generated by internal combustion engines (ICE) and related systems. 1-3 Much work has already been carried out on ICE noise and piston slap, trying to answer the questions: how to measure it?, how to separate it from other excitation sources?, how does it affect the engine's operation and total radiated noise?, etc. Piston slap is still an important mechanical excitation source and a noise generator in ICE. This literature review presents a synthesis of the main technical contributions already published about ICE noise and piston slap assessment and also the important influence of the oil film on this impact phenomenon. More than seventy references, including papers, theses, dissertations and books were studied for this purpose. The following presents the summary of this review. † Member of the International Institute of Acoustics and Vibration (IIAV) (pp 37-45)

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The growing demands for electrical energy, especially renewable, is boosting the development of wind turbines equipped with longer composite blades. To reduce the maintenance cost of such huge composite parts, the structural health monitoring (SHM) is an approach to anticipate and/or follow the structural behaviour along time. Apart from the development of traditional non-destructive testing methods, in order to reduce the use of intrusive instrumentation there is a growing interest for the development of “self-sensing materials”. An interesting route to achieve this, can be to introduce carbon nanofillers such as nanotubes (CNT) in the composite structures, which enables to create systems that are sensitive to both strain and damage. This review aims at updating the state of the art of this topic so far. A first overview of the existing SHM techniques for thermoset based wind turbine blades composites is presented. Then, the use of self-sensing materials for strain and damage sensing is presented. Different strategies are overviewed and discussed, from the design of conductive composites such as carbon fibres reinforced polymers, to the elaboration of conductive nano-reinforced polymer composites. The origins of sensing mechanisms along with the percolation theory applied to nanofillers dispersed in polymer matrices are also detailed.