The damped and sub-damped Ly \alpha systems ( DLAs and sub-DLAs ) traced in absorption against bright background quasars represent the main reserve of neutral hydrogen at high redshifts .
We used the archival Very Large Telescope ( VLT ) instrument Ultraviolet and Visual Echelle Spectrograph ( UVES ) high-resolution data of Q 0338-0005 ( z _ { em } = 3.049 ) to study abundances of the DLA ( z _ { abs } = 2.2298 ) and sub-DLA ( z _ { abs } = 2.7457 ) along the line of sight .
We estimated column densities of H i and various elements present in the DLA and sub-DLA through Voigt profile fitting .
The DLA throgh shows the Ly \alpha emission from the its host galaxy .
We derive the metallicities of the DLA and sub-DLA with [ Zn/H ] = -0.67 \pm 0.18 and [ S/H ] = -1.45 \pm 0.17 , respectively .
We compared our abundances of the DLA and sub-DLA with other high resolution DLA and sub-DLA metallicities and find that both populations show an overall increase of metallicity with decreasing redshift .
However , sub-DLAs usually have higher metallicities than the DLAs .