VSS_FILE_SPEC_BACKUP_TYPE enumeration. The VSS_FILE_SPEC_BACKUP_TYPE enumeration is used by writers to indicate their support of certain backup operationsâsuch as incremental or differential backupâon the basis of file sets (a specified file or files).
Blue ice (aviation) Blue ice, in the context of aviation, is frozen sewage material that has leaked mid-flight from commercial aircraft lavatory waste systems. It is a mixture of human biowaste and liquid disinfectant that freezes at high altitude. The name comes from the blue color of the disinfectant. Airlines are not allowed to dump their waste tanks in mid-flight, and pilots have no mechanism by which to do so; however, leaks sometimes do occur.
Why are glaciers blue? Small ice pieces, as well as snow, looks white, because the sunlight shining onto them gets completely reflected back, and no absorption of light by the ice particles take place. Hence, small ice pieces and snow appear white. However, large ice bergs and glaciers in most places appear blue in color. In nature, there are other things that appear blue, like the sky and sea water. But the phenomena involved in both cases that makes them appear blue are different, although they result in the same blue color.