"becomes improved" is a correct and usable phrase in written English.
You can use it when discussing something that has undergone positive change, or when describing a process of improvement that has taken place. Example: "Through consistent practice and dedication, her handwriting slowly becomes improved, and her teachers begin to praise her neatness."
Narrower the rib width is, performance of a cell becomes improved in the range investigated.
I should add that the surface becomes improved by use, which can hardly be said of the composition on the sides of the safety-match boxes.
By then she was being wooed by directors from the Museum of Modern Art and elsewhere, though Claribel's will stated that the collection should be given to the Baltimore Museum "if the spirit of appreciation of modern art in Baltimore becomes improved".
After gamma irradiation, the DO value of the effluent becomes improved and approaches to the standard value (4.5 8 ppm) for irrigation water (GoB, ECR 1997).
The theoretical fitting becomes improved with increased size N, and it is very good for N = 100 within the range of U = 20 intercross generations.
Experimental study revealed that the NiMnGa-FSMAP/epoxy smart composites exhibit both tensile ductility and SME, and that shape memory properties become improved by decreasing particle size of FSMAP.
The final cause of this contest amongst the males seems to be that the strongest and most active animal should propagate the species, which should thence become improved.
Postural sway on quiet bilateral standing was reduced after THA as previously shown (Wykman and Goldie 1989), and the natural interpretation would be that an impaired postural stability due to OA became improved after THA.
The western extension of the Genesee Road to Buffalo soon followed suit and also became an improved Macadam toll road, the Ontario and Genesee Turnpike, in 1805.
Barrie's mysterious, anarchic vision becomes an improving moral fable, tinged with mawkish sentimentality.
