People tend to check in during these times:
Even though it's a library, you still have people talking as if it's the cafeteria. So you must use the library, be sure to have headphones on, so you can listen to something that's worth hearing.
Bring your own computer and snag a group study room. Nice and quiet- and there are outlets!
Quiet on the upper floors
Take the elevator to the upper floors... its more quiet