Hundreds of science projects representing many thousands of hours of work go on display today in Ames at the State Science and Technology Fair of Iowa. Fair director Andrea Spencer says there are about 430 students from Iowa junior and senior high schools competing this year.The top prize for high school competitors is a five thousand dollar scholarship to any Iowa university. Spencer’s seen some of the projects already at regional science fairs and she says this year’s batch will make the judges work extra-hard to choose the winners.About 350 projects are on display today and tomorrow at Iowa State University’s Hilton Coliseum. The projects are divided into physical and biological science categories. Spencer says one young man from Stuart-Menlo worked on an unusual agricultural project.Spencer herself was an exhibitor at the fairs when she was in junior high and high school and she’s now working on her graduate degree in agricultural education at I-S-U.