Made available in DSpace on 2015-05-15T11:46:02Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 425597 bytes, checksum: 2cb5c42e376ba77764139fbc3fcdaf15 (MD5) Previous issue date: 2011-07-02 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / We consider the semilinear heat equation involving gradient terms in a bounded domain of Rn. It is assumed the non-linearity is globally Lipschitz. We prove that the system is approximately controllable when the control acts on a bounded subset of the domain. The proof uses a variant of a classical fixed point method and is a simpler alternative to the earlier proof existing in the literature by means of the penalization of an optimal control problem. We also prove that the control may be built so that, in addition to the approximate controllability requirement, it ensures that the state reaches exactly a finite number of constraints. / Consideremos a equação do calor semilinear envolvendo termos do gradiente em um domínio limitado do Rn. Assumimos que a não-linearidade é globalmente Lipschtz. Usando o método do ponto fixo, provamos que o sistema é finito-aproximadamente controlável e nulamente controlável, quando o controle age em um subconjunto não vazio do domínio.