Glow discharge -optical emission spectroscopy of different plasma gases such as H2 , N2 , N2-H2 and Ar-N2 generated by a cost effective 50 Hz pulsed-DC electrical power source is carried out to investigate the different excitation and ionization processes involved in the production of active species, for surface nitriding of materials. Spectroscopic study of hydrogen Balmer - line profiles are performed in an abnormal glow region of hydrogen plasma for investigating the dependencies of their line shapes and intensities on discharge parameters. A technique based on determining the relative...