Sentence:  <WSD>Dross</WSD> is related with the incomplete expulsion of the melt from the bottom of the  kerf. For precision applications where the clean cutting edges are important the formation of <WSD>dross</WSD> at the bottom of the cutting kerf must be controlled. This requires deep understanding of the mechanisms of <WSD>dross</WSD> formation and the various materials and laser-cutting parameters which potentially control the formation of <WSD>dross</WSD>. For example, the highly cleaned (<WSD>dross</WSD>-free) cutting edges can be obtained in ... 
Meaning of the word marked with <WSD> tags:  A waste product from working with metal.