Sandia Borders High-Level Model (HLM) (IMAGE) DOE/Sandia National Laboratories Caption Sandia researcher Donna Djordjevich (left) demonstrates the Borders High-Level Model (HLM) to a visitor. Credit Dino Vournas (Sandia National Labs) Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.