The most common shielding gases used for these main arc welding processes include argon (Ar), helium (He), carbon dioxide (CO2) and oxygen (O2). While Ar, He and CO2 may be used by themselves (i.e. 100%) for certain applications, in other cases the four gases are mixed together in different combinations to form shielding gas blends.
Cluster reduction in speech is when a consonant cluster, that is two or three consonants occurring in sequence in a word (like ândâ in friend), is reduced by a child into a single consonant through omission.
Overview. 1  Radiofrequency tissue reduction, or somnoplasty, is a simple outpatient procedure to help people suffering from sleep apnea or other sleep-related problems. This procedure enlarges the space within the nose and throat area, allowing for easier breathing during sleep.