We study the various translational and orientational dynamics of water molecules confined inside carbon nanotube using atomistic Molecular dynamics simulation (MD). We also give the thermodynamics of water entry inside hydrophobic nanotube by calculating the Helmholtz free energy of water using two-phase thermodynamic (2PT) method. We also propose a mechanism of water permeation in helium impermeable grapheme oxide (GO) membrane based on potential of mean force (PMF) calculation. Our PMF calculation shows that the equilibrium interlayer distance between the oxidized part of the GO sheets in helium is at 4.8 Ã… leaving no space for helium permeation. In contrast, the PMF of the oxidized part of the GO in water shows two minima, one at 4.8 Ã… and another a t 6.8 Ã…, corresponding to no water and a water filled region, thus giving rise to a permeation path. Finally, if time permits, we will discuss the proton kinetic energy anomaly for confined water.