The Commission Proposal for a Directive on Double Taxation Dispute Resolution Mechanisms: Will it resolve the remaining double taxation issues within the EU?

Double taxation has been widely accepted that constitutes an obstacle to the functioning of the single market. The European Union has adopted some uniform measures to have double taxation eliminated, for example, the Parent-Subsidiary Directive and the Interest-Royalty Directive. In addition, the Arbitration Convention has been concluded between Member States to eliminate double taxation in respect of transfer pricing adjustments. However, they all have limited scope and are unable to provide broad protection to the taxpayers. To improve the existing double taxation resolution mechanism, the European Commission proposed a directive in October 2016. This thesis aims to identify the remaining double taxation issues which cannot be resolved by the current EU legislation and to find out whether the Proposed Directive will provide a resolution to these issues

Experimental Tests of DC SFCL under Low Impedance and High Impedance Fault Conditions

DC system protection is more challenging than that for AC system due to the rapid rate of rise of the fault current and absence of natural current zero-crossing in DC systems. Superconducting fault current limiter (SFCL) in DC systems is a promising technology to reduce the fault current level and the rate of rise of the fault current, and also SFCLs have no resistance during normal operation. In this paper, the behaviors of an SFCL coil are investigated under both low impedance and high impedance fault conditions in DC systems. In the low impedance fault condition system, the SFCL coil performs effective limitation of the fault current level under different prospective fault current levels. The application of SFCLs with limited inductance in the DC system can be a potential solution to effectively suppress the fault current under low impedance short-circuit faults. The SFCL coil under the high impedance fault condition can only limit the prospective fault current when it is much higher than the critical current of the coil

Preliminary Design of DC Resistive Superconducting Fault Current Limiter for ASCEND

Airbus UpNext has launched an Advanced Superconducting and Cryogenic Experimental powertraiN Demonstrator (ASCEND) project in 2021 to develop a superconducting electric aircraft propulsion system. The demonstrator system power is rated at 500 kW with the dc voltage of 300 V. A dc networks can achieve smaller footprint and improved distribution efficiency. However, fault management in dc networks is much more challenging than ac systems because: firstly, there is no natural zero-crossing of the current to isolate the fault; and secondly, the rate of rise of fault currents is often significantly higher due to lower system impedances. Resistive superconducting fault current limiter (RSFCL) is a passive device that provides protection without requiring external input, making it inherently reliable. Non-inductive bifilar pancake RSFCL coils supported by G10 former are designed and built based on ASCEND system specification. This paper will present the design of RSFCL using 2G high temperature superconductor tapes for ASCEND demonstrator. A dc fault current testing circuit is built for testing of RSFCL. RSFCL is experimentally tested from 65 K to 77 K in the sub-cooled liquid nitrogen cryostat. The current limitation and recovery time are compared for different operating temperatures. In conclusion, RSFCL using HTS tapes demonstrates effective and fast current limitation within 1ms, which significantly improves the reliability of the system.</p

Integration of Superconducting Fault Current Limiter and DC Circuit Breaker for Electric Aircraft DC Network

Large-scale electric aircraft are a promising technology that could revolutionise air travel to reduce the environmental impact. Fault current limitation and interruption technology is crucial to realise the safety and reliability of the electric aircraft, in particular for large-scale electric aircraft using a DC distribution network. This paper proposes to integrate a resistive superconducting fault current limiter (SFCL) with a cryogenic DC solid-state circuit breaker (SSCB) so that the SFCL limits the fault current to acceptable levels in DC networks allowing the SSCB to operate quickly and reliably. A sub-cooled liquid nitrogen cryostat, which can be controlled from 65 K to 77 K, is designed and built for the integration of SFCL and DC SSCB. An SFCL and SSCB prototype is designed and experimentally tested at cryogenic temperatures, which successfully demonstrates the ability to limit and interrupt currents at cryogenic environment

Research on the Protective Effect of Twin-groyne Arrangement on Riverbank

A curved channel with intersecting streams can be easily scoured by incoming flow, and the concave bank is badly damaged. This research showed that the twin-groyne could effectively adjust and optimize the flow velocity distribution, change the shape of the free water surface of the bend, prevent erosion, and promote silting on the concave bank, and it could provide a scouring and silting effect on the convex bank. When the spacing of twin-groyne was increased to more than four times the body length of the single-groyne (spur dike), the protective effect on the concave bank was weakened, and the scouring and silting effect of the convex bank was reduced. Excessive spacing of the twin-groyne could cause local erosion damage to the concave bank. When the distance exceeded the theoretical optimum, it was equivalent to the effect of single-groyne. With the increase in the submergence degree, the velocity of the concave bank decreased first and then increased, while the velocity of convex bank decreased continuously. The protective effect of a non-submerged twin-groyne with a dam spacing of four times the body length of the single-groyne was better than that of other conditions, and it is recommended to be used in practice

Experimental Test and Analysis of AC Losses in Multifilamentary MgB ₂ Wire

AC losses in superconductors are essential for the design of cooling system for large scale power applications. Magnesium diboride (MgB2 ) superconducting wires have been investigated and manufactured over the last decade due to cheap raw materials and flexibility for coil design. In addition, multifilamentary MgB2 wires have been manufactured to reduce ac losses. In this paper, self-field ac losses of multifilamentary MgB2 wires with magnetic barrier are investigated using both experimental and numerical methods. A short straight wire sample and a coil sample are tested under various temperatures and frequencies between 16-and 128-Hz. The test results show that the transportation loss is independent of the operating temperature. On basis of both theoretical and numerical study, it is found that hysteresis loss in superconductor accounts only for a small fraction of the transportation losses, ferromagnetic hysteresis loss in the magnetic barrier dominates when the transport current is low, whereas eddy current loss dominates when the transport current is close to the critical current

Neutrino Physics with JUNO

The Jiangmen Underground Neutrino Observatory (JUNO), a 20 kton multi-purposeunderground liquid scintillator detector, was proposed with the determinationof the neutrino mass hierarchy as a primary physics goal. It is also capable ofobserving neutrinos from terrestrial and extra-terrestrial sources, includingsupernova burst neutrinos, diffuse supernova neutrino background, geoneutrinos,atmospheric neutrinos, solar neutrinos, as well as exotic searches such asnucleon decays, dark matter, sterile neutrinos, etc. We present the physicsmotivations and the anticipated performance of the JUNO detector for variousproposed measurements. By detecting reactor antineutrinos from two power plantsat 53-km distance, JUNO will determine the neutrino mass hierarchy at a 3-4sigma significance with six years of running. The measurement of antineutrinospectrum will also lead to the precise determination of three out of the sixoscillation parameters to an accuracy of better than 1\%. Neutrino burst from atypical core-collapse supernova at 10 kpc would lead to ~5000inverse-beta-decay events and ~2000 all-flavor neutrino-proton elasticscattering events in JUNO. Detection of DSNB would provide valuable informationon the cosmic star-formation rate and the average core-collapsed neutrinoenergy spectrum. Geo-neutrinos can be detected in JUNO with a rate of ~400events per year, significantly improving the statistics of existing geoneutrinosamples. The JUNO detector is sensitive to several exotic searches, e.g. protondecay via the $p\to K^++\bar\nu$ decay channel. The JUNO detector will providea unique facility to address many outstanding crucial questions in particle andastrophysics. It holds the great potential for further advancing our quest tounderstanding the fundamental properties of neutrinos, one of the buildingblocks of our Universe

Potential of Core-Collapse Supernova Neutrino Detection at JUNO

JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve