Comparative Analysis of Ultra-Fine Bar Refining and Valley Beating on Softwood and Hardwood Kraft Pulps: Implications for Fiber Integrity and Paper Strength Enhancement. - Park, Hyeong-Hun; Kim, Chul-Hwan; Park, Ju-Hyun; Park, Min-Sik; Lee, Jae-Sang (Applied Sciences (2076-3417), 2025)