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.
Spotting a live louse or nymph (a young louse) is often the only sign of an infestation. Seeing nits alone doesn't confirm an infestation. In many children, head lice don't cause any discomfort. When symptoms do happen, the most common problem is itching that may start weeks or even months after the lice move in.