plane of symmetry वाक्य

Its only " weak points " are the two polar cusps, the points where field lines closing at noon (-z axis GSM ) get separated from those closing at midnight ( + z axis GSM ); at such points the field intensity on the boundary is zero, posing no barrier to the entry of plasma . ( This simple definition assumes a noon-midnight plane of symmetry, but closed fields lacking such symmetry also must have cusps, by the fixed point theorem .)
The crystal showed five prism faces of the form " m " { 100 } and a small face " a " { 110 }, with no pyramidal or basal faces, upon x-ray diffraction a Lauer gram along the " c "-axis revealed a hexagonal axis with vertical planes of symmetry, this study showed that the structure has a hexagonal and not a rhombohedral lattice . further studies conducted on synthetic ettringite by use of x-ray and powder diffraction confirmed earlier assumptions and analyses.
For instance, a basis set with fixed orientation relative to an airplane can be defined as a set of three orthogonal unit vectors " b " 1, " b " 2, " b " 3, such that " b " 1 is parallel to the chord line of the wing and directed forward, " b " 2 is normal to the plane of symmetry and directed rightward, and " b " 3 is given by the cross product b _ 3 = b _ 1 \ times b _ 2.