Sentence:  Some 80 reaction tubes from 13 manifold fillings were illuminated in the temperature range from 40 to 85 ` in a further endeavor to determine the cause of the irreproducibility and to obtain information on the activation energy and the effect of light <WSD>intensity</WSD> . 
Meaning of the word marked with <WSD> tags:  the amount of energy transmitted (as by acoustic or electromagnetic radiation)