I.across [美 əˈkrɔs, əˈkrɑs, 英 əˈkrɒs]副across often appears as the second element of certain verb structures in English (come across, cut across, put across, etc). For translations, see the relevant verb entry (come, cut, put, etc)
Packing offers the advantage of a lower pressure drop across the column (when compared to plates or trays), which is beneficial while operating under vacuum.