In step 2 of an electrophilic addition, the positively charged intermediate combines with (Y) that is electron-rich and usually an anion to form the second covalent bond.Step 2 is the same nucleophilic attack process found in an SN1 reaction.n step 2 of an electrophilic addition, the positively charged intermediate combines with (Y) that is electron-rich and usually an anion to form the second covalent bond.
A. The Sleep Test Optimization Program is prior. authorization initiative for Polysomnography (PSG). There are two types of sleep studies â (1) Attended. Sleep Studies - performed in an outside facility, office, sleep clinic or laboratory; and (2) Unattended.
How It Is Done. Sleep studies are usually done by a trained sleep lab technician. The studies are usually scheduled for evening and night hours (10 p.m. to 6 a.m.) in a special sleep lab. But if you usually sleep during the day, your test will be done during the hours you normally sleep.