Some remarks on the thermodynamics of charged AdS black holes with cloud of strings and quintessence

In this paper we investigate the combined effects of the cloud of strings and quintessence which surround a Reissner–Nordstrom AdS black hole on its thermodynamics. We treat the cosmological constant as a thermodynamic pressure whose conjugate variable is the volume. It is shown how the cloud of strings affect the thermodynamic variables, as for example, temperature, entropy, internal energy and heat capacity. The critical expressions for temperature, pressure and specific volume are obtained and the critical exponents calculated. Concerning the heat engine, we calculate its efficiency and show how this quantity is influenced by the presence of the cloud of strings and quintessence.