In this thesis the problem of energetic particle (electrons and ions) acceleration by an ensemble of shock waves is addressed. Shock waves are generated, moving randomly, inside a turbulent flow (e.g. jets and hot spots of extragalactic radio sources) or in an involving and constantly changing active region on the Sun. The acceleration is based on the 'shock drift mechanism' using the adiabatic treatment. The transport and the radiation of the particles in stochastic magnetic fields is also studied.The resulting energy distribution of the energetic particles is calculated analytically and numerically, after their interaction with a number of shock waves. Two models are presented, the first one is an application to the solar flare problem (see Anastasiadis A.
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