A method to detect and characterize at least one defect in a specimen using an apparatus comprises steps of: generate a plurality of wave signals on the specimen , by using an impact source , for the wave signals to propagate within the specimen;…

The present invention discloses a method of preparing a controlled-release nitrogen, phosphorus and potassium (NPK) compound fertilizer. The method comprises steps of preparing a PLA biopolymer at a predefined concentration between 5-15 %w/v by…