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Since the concept of Self-Organized Criticality was introduced in terms of BTW Sandpiles model, its major features have been known as broad power law distributions without any tuning parameters. In some selforganized critical systems like brain and neural networks, some evidences and experiments show a periodic or non-power law distribution of avalanches in addition to the power-law distributions of avalanches. In this thesis we try to observe the same phenomenon in the well-known SOC models, namely the BTW and Manna sandpile models. We have considered small lattice sizes with periodic boundary conditions and a small amount of dissipation. Within such conditions we observe a periodic-like... 

It has been about a century since the introduction of the theory of quantum mechanics. This theory is a branch of physics that describes the behavior of nature in very small scales and microscopic systems . Since no quantum system is entirely isolated from its surroundings , it is necessary to study their interactions with the environment to understand them accurately. The theory of open quantum systems provides the theoretical and conceptual framework needed to consider these interactions. Then using the appropriate quantum operations , the evolution of the combined system can be investigated. Moreover , considering the environmental effects, some quantum features such as dissipation...