Carbon dioxide (CO 2) is usually pumped as a liquid, usually below 5Â°C (41Â°F) and a pressure of about 50 bar. The solvent is pumped as a liquid as it is then almost incompressible; if it was pumped as a supercritical fluid, much of the pump stroke would be used up in compressing the fluid, rather than pumping it.
The word lice is plural for louse. Head lice are spread by personal contact or the sharing of combs, brushes, caps, and other clothing. Head lice are a common problem with preschool and schoolchildren. Head lice cause a tickling feeling of something moving in the hair, itching, and sores on the head.
For the disease known as head lice, see Head lice infestation. The head louse (Pediculus humanus capitis) is an obligate ectoparasite of humans that causes head lice infestation (pediculosis capitis). Head lice are wingless insects spending their entire life on the human scalp and feeding exclusively on human blood.