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.
Oxygen therapy is one of the best treatments to stop a cluster headache. Oxygen therapy relieves headache pain within 15 minutes in more than 7 out of 10 people who use it. It works best when started right when a cluster headache starts. But you need to repeat the treatment when the next headache begins.