Equation Icon  N (t,y) = n (y ), (357 ) A (t,y) = a(t)n(y), (358 ) ( ρ0) n(y) = cosh μy − 1 + λ sinh μ|y|, (359 ) a(t) = a expH (t − t), (360 ) 02 ( 0 ) 0 H2 = κ--ρ 1 + ρ0- , (361 ) 0 3 0 2λ