Perhaps you should try some spelling variations:
"5 nn decrease" » "k nn decrease" (Expand Search), "_ nn decrease" (Expand Search), "5 nn decreased" (Expand Search), "5 nn increase" (Expand Search)
"50 ppm decrease" » "50 ppm decreased" (Expand Search), "50 ppm increase" (Expand Search)
"5 we decrease" » "5 we decreased" (Expand Search), "5 we increase" (Expand Search)
"45 c decrease" » "45 c decreased" (Expand Search), "45 c increase" (Expand Search)

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("50 ppm decrease") OR ((((("5 nn decrease") OR ("5 we decrease"))) OR ("45 c decrease"))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"50 ppm decrease\") OR (((((\"5 nn decrease\") OR (\"5 we decrease\"))) OR (\"45 c decrease\"))))*".
• Removing quotes may allow a broader search: (( 50 ppm decrease ) OR ((((( 5 nn decrease ) OR ( 5 we decrease ))) OR ( 45 c decrease ))))*.