SEARCH Articles Figures Tables Bio-oil upgrading over Ga modified zeolites in a bubbling fluidized bed Bubble formation in gas fluidized beds Bubble in gas-fluidized bed Bubble population in a fluidized bed Bubbling bed Bubbling fluidization Bubbling fluidized beds Fluidization bubbles Fluidized beds bubbles In fluidized beds Single Bubble in a Fluidized Bed