Since the types of foods and ways to prepare them are so varied, it's no surprise that there are several concentrations available. (learnhowtobecome.org)
Frequently it is even possible to observe the effects of several concentrations of interstellar gas between Earth and the background stars and thereby determine the kinematics of the gas in different parts of the Galaxy. (britannica.com)
«We had to try several concentrations of alginate in order to obtain a sphere, solid outside and liquid inside,» Prista explains. (sciencemag.org)