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 <WSD>light</WSD> intensity . 
Meaning of the word marked with <WSD> tags:  (physics) electromagnetic radiation that can produce a visual sensation