The Kansas state university endowment association may utilize the income from such property or if they deem advisable is hereby authorized to sell and convey such property at not less than the appraised value thereof. All income received from such property and the proceeds from the sale of any of such property shall be used only for the development, expansion and improvement of a Kansas state university museum and art center at Manhattan, Kansas, as required under the terms of the last will and testament of the late Charles V. Kincaid, of Independence, Kansas.