def calMassTransferCoefficientEq1(Sh, GaDiCoi, CaPaDi):
    """ 
    calculate mass transfer coefficient [m/s]
    args:
        Sh: Sherwood number
        GaDiCoi: gas component diffusivity coefficient [m^2/s]
        CaPaDi: catalyst particle diameter [m]
    """
    # try/except
    try:
        # characteristic length [m]
        ChLe = CaPaDi/2
        return (Sh*GaDiCoi)/ChLe
    except Exception as e:
        raise