Two Questions In Triangulated Categories

This thesis for Master degree discusses two basic questions in the theory of triangu-lated categories. Firstly, for the Octahedral Axiom, I give a complete form and proof of the Pull-back Axiom and the Push-out Axiom, which both are equivalent to the Octahedral Axiom. This compensates a missing commutative square in [AS]. Secondly, by using the filtration in triangulated categories and the cohomological groups induced by t-structure, in-troduced by S. Gelfand and Yu. Manin, I obtain three different equivalent descriptions for the boundedness of t-structures.