RANCANG BANGUN DAN UJI TEKNIK GASIFIER DOWNDRAFT PORTABEL BERBAHAN BRIKET KULIT KAYU GELAM (Melaleuca leucadendron Linn.) = DESIGN AND TECHNICAL TESTING OF PORTABLE DOWNDRAFT GASIFIER USING FUEL OF GELAM WOOD BARK BRIQUETTES (Melaleuca leucadendron Linn.) - SIREGAR, PIPIN YULIANTI (2018)