TY JOUR TI RESEARCH ON CHOOSING THE BEST GAS FOR THE FLETTNER BALLOON, AN UNCONVENTIONAL POWER GENERATOR ENERGY DEVICE KW Flattner balloon KW environment KW gas KW helium KW hydrogen JO Operation of Maritime Transport AU VASILESCU, M.. AU Epikhin, A.. PY 2023 IS 0 PB Budget Educational Institution of Higher Education “Admiral Ushakov State Maritime University”