Both a compressed gas cylinder and its regulator are at room temperature with all valves in the off position. After the cylinder is opened and gas begins flowing, you note that the regulator is extremely cold to touch
Which of the following principles best explains this observation?
a. Adiabatic compression
b. Gay-Lussac's law
c. Joule-Thompson effect
d. Venturi principle
ANS: C
The rapid expansion of real gases causes substantial cooling. This phenomenon of expansion cooling is called the Joule-Thompson effect. Adiabatic compression can also occur in gas delivery systems where rapid compression occurs within a fixed container. The rise in temperature caused by this rapid compression can ignite any combustible material in the system. It is for this reason that RTs must take care to clear any combustible matter from high-pressure gas delivery systems before pressurization.
You might also like to view...
You are ordered to give 2.0 mg of epinephrine 1:10,000 by the endotracheal route during cardiac arrest as the intravenous line has not yet been established. Epinephrine is supplied as 0.1 mg/mL. How many milliliters will you give?
a. 1 mL b. 10 mL c. 20 mL d. 0.20 mL
Night sweats are not associated with benign conditions.
Answer the following statement true (T) or false (F)
Which of the following cranial nerves innervates muscles for chewing?
A. Olfactory nerves B. Trochlear nerves C. Trigeminal nerves D. Facial nerves E. Abducens nerves
When incising the cranium between burr holes, what attachment to the powered craniotome is necessary to prevent injury of underlying tissues?
a. #3 Penfield dissector b. dural guard with footplate c. smoke evacuator d. wire-pass drill bit