High resolution , high S/N spectra have been obtained for a sample of 90 F and G main-sequence disk stars covering the metallicity range -1.0 < \mbox { [ Fe / H ] } < +0.1 , and have been analysed in a parallel way to the work of Edvardsson et al .
( [ 1993a ] ) in order to re-inspect their results and to reveal new information on the chemical evolution of the Galactic disk .

Compared to Edvardsson et al .
the present study includes several improvements .
Effective temperatures are based on the Alonso et al .
( [ 1996 ] ) calibration of color indices by the infrared flux method and surface gravities are calculated from Hipparcos parallaxes , which also allow more accurate ages to be calculated from a comparison of M _ { V } and T _ { eff } with isochrones .
In addition , more reliable kinematical parameters are derived from Hipparcos distances and proper motions in combination with accurate radial velocities .
Finally , a larger spectral coverage , 5600 - 8800Å , makes it possible to improve the abundance accuracy by studying more lines and to discuss several elements not included in the work of Edvardsson et al .

The present paper provides the data and discusses some general results of the abundance survey .
A group of stars in the metallicity range of -1.0 < \mbox { [ Fe / H ] } < -0.6 having a small mean Galactocentric distance in the stellar orbits , \mbox { $R _ { m } $ } < 7 kpc , are shown to be older than the other disk stars and probably belong to the thick disk .
Excluding these stars , a slight decreasing trend of [ Fe/H ] with increasing R _ { m } and age is found , but a large scatter in [ Fe/H ] ( up to 0.5 dex ) is present at a given age and R _ { m } .
Abundance ratios with respect to Fe show , on the other hand , no significant scatter at a given [ Fe/H ] .
The derived trends of O , Mg , Si , Ca , Ti , Ni and Ba as a function of [ Fe/H ] agree rather well with those of Edvardsson et al. , but the overabundance of Na and Al for metal-poor stars found in their work is not confirmed .
Furthermore , the Galactic evolution of elements not included in Edvardsson et al. , K , V and Cr , is studied .
It is concluded that the terms “ \alpha elements ” and “ iron-peak elements ” can not be used to indicate production and evolution by specific nucleosynthesis processes ; each element seems to have a unique enrichment history .