The p24 antigen test can detect the p24 protein on average 10 to 14 days after infection with HIV.2,3,11,12 One drawback of this test is that levels of the p24 protein peak at around three to four weeks after exposure to HIV and are usually not detectable after five to six weeks (and sometimes even earlier).
Liquid nitrogen is nitrogen in a liquid state at an extremely low temperature.It is produced industrially by fractional distillation of liquid air. Liquid nitrogen is a colorless clear liquid with density of 0.807 g/ml at its boiling point and a dielectric constant of 1.43.iquid nitrogen is nitrogen in a liquid state at an extremely low temperature.
Theory The heat of vaporization of a liquid is the energy that must be supplied in order to convert a unit mass of the liquid to the gas phase. A typical unit is Joules/gram (J/g). Liquid nitrogen at atmospheric pressure has a boiling point of 77.3 K and remains at its boiling point throughout the experiment.se Igor to produce graphs of mass versus time and determine the three rates of vaporization via a linear fit to the data using Igor. Remember, for each rate you are making a linear fit to a part of the data. 6. Calculate the latent heat L and compare it to the accepted value of 199.5 J/g for liquid nitrogen.