Self-contained breathing apparatus pressure changes with ambient temperature. As temperature decreases, the pressure inside the cylinder decreases. The relationship between the temperature and the pressure of a gas is defined by the formula "PV" = "nRT". (See Universal gas constant.) What is particularly important to understand from the formula is that the temperature is in kelvins, not degrees Fahrenheit. Consider the freezing point of water at 32 °F (0 °C, 273.15 K) and compare it to 96 °F (35.6 °C or 308.71 K; normal human body temperature is 37 °C). While 96 is arithmetically three times 32, the difference in temperature from a
Northwest Normal University Northwest Normal University Northwest Normal University, also translated into English as Northwestern Normal University (), is a comprehensive university in Lanzhou, Gansu Province of the People's Republic of China. The university is authorized by the State Council of the Central Government of the People's Republic of China to grant associate degrees, bachelor's degrees, master's degrees, and doctoral degrees in more than 80 subject areas. Northwest Normal University (NWNU) is a key university under the joint construction of the People’s Government of Gansu Province and the Ministry of Education of China. It is also one of the 14 state-supported universities in