Today, the production of energy from waste is not a new process; however, its implementation and application continue to be a challenge in developing countries. Despite the abundance of valuable waste in the urban markets of these countries, practices aiming at renewable energy generation are...

Under some weakenings of the condition of the well-known fixed point theorems of Brouwer, Kakutani and Banach the existence of approximate fixed points turns out to be still guaranteed. Also an approximate fixed point theorem is given for certain nonexpansive maps.