A utility cart which is capable of being readily converted from a first configuration as a conventional utility cart with the area above a bottom table being open into a second configuration as a bin cart, including a number of outwardly extending storage bins. The recording device includes a light generating and irradiation unit, a recording unit, a tracking mechanism, a first tracking error signal generating unit, a second tracking error signal generating unit, a tracking servo control unit, and a control unit. This continuous separation process can be furnished as the integration of multiple partial fluidized beds or cells; operated under designated pressure level to instantaneous and simultaneous proceeding of determined mass-transfer phenomena.