Changes made in thesis for minor ammendments

- P2 typo
- P23 Added to abbreviations list
- P24 not just elastic composites
- P25 Bragg interference of scattered acoustic waves
- P25 expanded revolutionary components
- P26 Rayleigh line replaced with SAWs
- P26 are typo
- P27 holes typo
- P29 abbreviations
- P30 clarification of particle trajectory
- P31 Figure 2.1 caption
- P35 change of notation to i, positive kx from j, negative kx
- P35 I tried putting eqs. 2.9 and 2.11 after 2.10, 2.12 and 2.13 but it didn't work because the 4 solutions mentioned in the paragraph after 2.13 are a result of substitution into 2.11. It just didn't flow very well with this change.
- P36 uo and phi0 aren't constant scalars.
- P36 the solutions are linearly dispersive rather than non-dispersive
- P36 changed wording of the boundary condition to 'no net surface traction' instead of 'no net force'. Also changed the boundary condition to the more neat x3.T = 0 instead of T11 = T22 = T33 = 0.
- P36 changed i-j notation
- P37 chnaged i-j notation... and so on through subsequent eqautions
- P37 clarification of D3 being electric displacement component normal to the surface.
- P39 clarification of x axis in the caption
- P40 corrected the subheading numbering.
- P40 abbreviation definition
- P42 Re-wording of Euler angle explanation for clarity.
- P42 Added citation in figure caption
- P43 simplified free and metallized cases for SAW velocities
- P58 PnCs aren't only elastic composites.
- P58 eigenfrequencies
- P58 corrected the missing vector notations of lattice and reciprocal lattice vectors.
- P59 changed transverse subscript from t to T
- P62 definition of y axis in caption.
- P63 distinction of acoustic and elastic waves.
- P65 typo
- P66 typo
- P68 changed wording of rdiated energy to leaked energy
- P68 removed the definition that metamaterials are periodic because they don't strictly have to be.
- P69 'the' instead of 'this'
- P69 briefly explained Lamb waves.
- P70 typo
- P71 syntax
- P72 explained the Bragg band gap.
- P79 improved the section describing the work by Columbi et al. as requested.
- P81 defined single/double negative materials for acoustics.
- P92 reasoning for using the MUMPS solver
- P93 dispersion of SAWs in PnCs, not the PnCs
- P94 syntax
- P100 typo
- P130 SAW bandgap not PnC bandgap and specify the shear BAW soundline.
- P138 Typo line
- P152 caption explains the arrow in b
- P162 rho is the density and v is the group velocity of the SAW modes.
- P174 added reasoning for origin choice
- P190 Added list of publications
- P191 Reviewed the formatting of all references. Lower cased initials were corrected.