Context. During protostellar collapse, conservation of angular momentum leads to the formation of an accretion disc. Little is known observationally about how and when the velocity field around the protostar shifts from infall-dominated to rotation-dominated. Aims. We investigate this transition in the low-mass protostar L1489 IRS, which is known to be embedded in a flattened, disc-like structu...

This work assesses the current instrumentation, method development, and applications in countercurrent chromatography (CCC) and centrifugal partition chromatography (CPC), collectively referred to as countercurrent separation (CCS). The article provides a critical review of the CCS literature from 2007 since our last review (J. Nat. Prod. 2008, 71, 1489-1508), with a special emphasis on the app...

GaInP/GaAs HBT inductorless wideband amplifiers using shunt-series shunt-shunt dual-feedback topology (Kukielka topology) and shunt-series series-shunt dual-feedback topology (Meyer topology) are demonstrated in this article. Three amounts of feedback are applied on each topology. At the high-gain mode, the Kukielka/Meyer wideband amplifier achieves the small-signal power gain of 30/27 dB with ...

We generalize the two-temperature model [Sanders and Walton, Phys. Rev. B 15, 1489 (1977)] for coupled phonon-magnon diffusion to include the effect of the concurrent magnetization flow, with a particular emphasis on the thermal consequence of the magnon flow driven by a nonuniform magnetic field. Working within the framework of the Boltzmann transport equation, we derive the constitutive equat...