NewTest

\[k_c = \frac{\kappa \sigma_c}{6} = \frac{\kappa}{6} \left\{

  \begin{align}
    & 0.4+3.5 \sin^2 \left( \frac{\pi}{2} \frac{W_s}{u_{*c}} \right)
      \text{   if   } \frac{W_s}{u_{*c}} \le 1 \\
    & 1.0+2.9 \sin^2 \left( \frac{\pi}{2} \frac{u_{*c}}{W_s} \right)
      \text{   if   } \frac{W_s}{u_{*c}} \gt 1 \\
  \end{align} \right.\qquad\qquad\text{(166)}\]