Sharif Digital Repository

Present work focuses on the influence of Heteroatom(s) on the bacisity of specific group of amines through the intramolecular hydrogen bonding. This group includes Aza-Crown Ethers specifically. We used Spartan and Gaussian packages to gain optimized structures for all compounds in order to explore the influence of the intramolecular hydrogen bonding on the bacisity of amines. All the gas phase optimizations and energy calculations were performed at the DFT/B3LYP/6-311++G(d,p) level of theory. The Hf/6-31+G(d,p) level was used for all single point calculations in the solution phase. As commonly used solvents in organic and biological reactions, the solution phase calculations were carried... 

In this thesis a brief review of the concept of vacuum has been studied. In addition, we shall see how we can determine the vacuum energy in a flat space-time. Also the renormalization and the regularization of zero point energy, which is 122 order of magnitude more than the critical density energy, has been represented. Then, we study supersymmetry which is a candidate to solve this problem. Furthermore, different ways to determine cosmological constant and the orbits of planets has been studied.Finally, by studying free fall experiments, the gravitational properties of vacuum has been represented.Caisimir effect, one of the most amazing predictions in the history of physics, and Lamb...