AUTHOR=Boretti Alberto , Nayfeh Jamal , Al-Maaitah Ayman TITLE=Hydrogen Production by Solar Thermochemical Water-Splitting Cycle via a Beam Down Concentrator JOURNAL=Frontiers in Energy Research VOLUME=9 YEAR=2021 URL=https://www.frontiersin.org/journals/energy-research/articles/10.3389/fenrg.2021.666191 DOI=10.3389/fenrg.2021.666191 ISSN=2296-598X