A novel extraction approach was developed based on rotating-disk sorptive extraction (RDSE). In this approach the rotating-disk extraction device consists of a Teflon disk, with a cavity that is loaded with a commercial sorbent phase selected according to the polarity of the analyte. To avoid leakage of the sorbent, the cavity is covered with a fiberglass filter and sealed with a Teflon ring. T...

Context. One of the most outstanding problems related to numerical models of galaxy formation is the so-called " angular momentum catastrophe " , i.e., the inability to explain theoretically the high angular momentum observed in local disk galaxies. Aims. We study the evolution of the angular momentum from z∼0.6 to z=0 to further our understanding of the mechanisms responsible for the large ang...

We study the energetics of a black hole-accretion disk system with magnetic connection: a Keplerian disk is connected to a Kerr black hole by a large-scale magnetic field going through the transition region. We assume that the magnetic field is locked to the inner boundary of the disk and corotates with the inner boundary, the accretion rate is low but the accretion from the disk can still prov...