Sharif Digital Repository

In the present study, we try to numerically simulate the nanofluid flooding method, which is one of the newest methods in this field. For this purpose, the nanofluid is considered as a single phase fluid that enters the porous petroleum reservoir containing oil. Since all porous petroleum reservoirs are heterogeneous, the porous grid is also considered heterogeneous and is solved using the finite element numerical method. The geometry considered in this study is a two-dimensional anticline medium that is heterogeneous. In this study, the effect of using different volume fractions of nanoparticles in nanofluid is studied. Capillary pressure or diffusion are considered in simulation and their... 

Botnets (networks of compromised computers) are often used for malicious activities such as spam, click fraud, identity theft, phishing, and distributed denial of service (DDoS) attacks. Most of previous researches have introduced fully or partially signature-based botnet detection approaches. In this paper, we propose a fully anomaly-based approach that requires no a priori knowledge of bot signatures, botnet C&C protocols, and C&C server addresses. We start from inherent characteristics of botnets. Bots connect to the C&C channel and execute the received commands. Bots belonging to the same botnet receive the same commands that causes them having similar netflows characteristics and...