12,085 research outputs found
Self-Synchronized Universal Droop Controller
In this paper, a self-synchronization mechanism is embedded into the universal droop controller
(UDC), which is applicable to inverters having an impedance angle between −π/2 rad and π/2 rad,
to form a self-synchronized UDC (SUDC). Both the voltage loop and the frequency loop of the UDC are
modified to facilitate the standalone and grid-connected operation of inverters. Importantly, the dedicated
phase-locked-loop that is often needed for grid-connected or parallel-operated converters is removed. The
inverter is able to achieve synchronization before and after connection without the need of a dedicated
synchronization unit. Since the original structure of the UDC is kept in the SUDC, the properties of the
UDC, such as accurate power sharing and tight output voltage regulation, are well maintained. Extensive
experimental results are presented to demonstrate the performance of the proposed SUDC for a gridconnected
single-phase inverter
Enhanced low C/N nitrogen removal in an innovative microbial fuel cell (MFC) with electroconductivity aerated membrane (EAM) as biocathode
© 2016 Elsevier B.V. A novel microbial fuel cell (MFC) was developed to enhance simultaneous nitrification and denitrification (SND) by employing electrons from the anode. The cathode chamber of the reactor consisted of a membrane aerated biofilm reactor (MABR) which was made of an electroconductivity aerated membrane. The maximum power density of 4.20 ± 0.12 W m−3was obtained at a current density of 4.10 ± 0.11 A m−2(external resistance = 10 Ω). Compared with an open-circuit system, the removal rates of NH4+-N and TN were improved by 9.48 ± 0.33% and 19.80 ± 0.84%, respectively, which could be ascribed to the electrochemical denitrification. The anode (chemical oxygen demand, COD) and cathode (NO3−) chambers reached the maximum coulombic efficiencies (CEs) of 40.67 ± 1.05% and 42.84 ± 1.14%, respectively. It suggested that the electroconductivity MABR has some advantages in controlling aeration intensity, thus improving SND and CEs. Overall, EAM-MFC could successfully generate electricity from wastewater whilst showing high capacity for removing nitrogen at a low COD/N ratio of 2.8 ± 0.07 g COD g−1N
Magnetic-field induced resistivity minimum with in-plane linear magnetoresistance of the Fermi liquid in SrTiO3-x single crystals
We report novel magnetotransport properties of the low temperature Fermi
liquid in SrTiO3-x single crystals. The classical limit dominates the
magnetotransport properties for a magnetic field perpendicular to the sample
surface and consequently a magnetic-field induced resistivity minimum emerges.
While for the field applied in plane and normal to the current, the linear
magnetoresistance (MR) starting from small fields (< 0.5 T) appears. The large
anisotropy in the transverse MRs reveals the strong surface interlayer
scattering due to the large gradient of oxygen vacancy concentration from the
surface to the interior of SrTiO3-x single crystals. Moreover, the linear MR in
our case was likely due to the inhomogeneity of oxygen vacancies and oxygen
vacancy clusters, which could provide experimental evidences for the unusual
quantum linear MR proposed by Abrikosov [A. A. Abrikosov, Phys. Rev. B 58, 2788
(1998)].Comment: 5 pages, 4 figure
Mass movement susceptibility mapping using satellite optical imagery compared with InSAR monitoring: Zigui County, Three Gorges region, China
Mass movements on steep slopes are a major hazard to
communities and infrastructure in the Three Gorges
region, China. Developing susceptibility maps of mass
movements is therefore very important in both current
and future land use planning. This study employed
satellite optical imagery and an ASTER GDEM (15 m)
to derive various parameters (namely geology; slope
gradient; proximity to drainage networks and proximity
to lineaments) in order to create a GIS-based map of
mass movement susceptibility. This map was then
evaluated using highly accurate deformation signals
processed using the Persistent Scatterer (PS) InSAR
technique. Areas of high susceptibility correspond well
to points of high subsidence, which provides a strong
support of our susceptibility map
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