Liquid nitrogen is a compact and readily transported source of dry nitrogen gas, as it does not require pressurization. Further, its ability to maintain temperatures far below the freezing point of water makes it extremely useful in a wide range of applications, primarily as an open-cycle refrigerant, including:
The height will be the bookcase height minus 30 inches, since that is where the fixed shelf is located. Bookcases 12-18 wide will only have one door, those 24-42 wide will have two doors, and those 48-60 will have four doors. The doors on 6-8 foot bookcases will have double panels since they are very tall.
If you analyse the contents of a typical bookshelf in an academic library, you will notice that many of the books are between 272 and 320 pages in length. The golden extent for many publishers is 288 pages (about 90â100,000 words without tables or figures).