Extreme vortex pinning in the non-centrosymmetric superconductor CePt3_{3}Si

We report on the vortex dynamics of a single crystal of the non-centrosymmetric heavy-fermion superconductor CePt$_{3}$Si. Decays of the remnant magnetization display a clean logarithmic time dependence with rates that follow the temperature dependence expected from the Kim-Anderson theory. The creep rates are lower than observed in any other centrosymmetric superconductor and are not caused by high critical currents. On the contrary, the critical current in CePt$_{3}$Si is considerably lower than in other superconductors with strong vortex pinning indicating that an alternative impediment on the flux line motion might be at work in this superconductor.Comment: 4 pages, 5 figure

Vortex avalanches in the non-centrosymmetric superconductor Li2Pt3B

We investigated the vortex dynamics in the non-centrosymmetric superconductor Li_2Pt_3B in the temperature range 0.1 K - 2.8 K. Two different logarithmic creep regimes in the decay of the remanent magnetization from the Bean critical state have been observed. In the first regime, the creep rate is extraordinarily small, indicating the existence of a new, very effective pinning mechanism. At a certain time a vortex avalanche occurs that increases the logarithmic creep rate by a factor of about 5 to 10 depending on the temperature. This may indicate that certain barriers against flux motion are present and they can be opened under increased pressure exerted by the vortices. A possible mechanism based on the barrier effect of twin boundaries is briefly discussed

Connected Bike-smart IoT-based Cycling Training Solution

The Connected Bike project combines several technologies, both hardware and software, to provide cycling enthusiasts with a modern alternative solution for training. Therefore, a trainer can monitor online through a Web Application some of the important parameters for training, more specifically the speed, cadence and power generated by the cyclist. Also, the trainer can see at every moment where the rider is with the aid of a GPS module. The system is built out of both hardware and software components. The hardware is in charge of collecting, scaling, converting and sending data from sensors. On the software side, there is the server, which consists of the Back-End and the MQTT (Message Queues Telemetry Transport) Broker, as well as the Front-End of the Web Application that displays and manages data as well as collaboration between cyclists and trainers. Finally, there is the Android Application that acts like a remote command for the hardware module on the bike, giving the rider control over how and when the ride is monitored

Possible re-entrant superconductivity in EuFe2As2 under pressure

We studied the temperature-pressure phase diagram of EuFe2As2 by measurements of the electrical resistivity. The antiferromagnetic spin-density-wave transition at T_0 associated with the FeAs-layers is continuously suppressed with increasing pressure, while the antiferromagnetic ordering temperature of the Eu 2+ moments seems to be nearly pressure independent up to 2.6 GPa. Above 2 GPa a sharp drop of the resistivity, \rho(T), indicates the onset of superconductivity at T_c \approx 29.5 K. Surprisingly, on further reducing the temperature \rho(T) is increasing again and exhibiting a maximum caused by the ordering of the Eu 2+ moments, a behavior which is reminiscent of re-entrant superconductivity as it is observed in the ternary Chevrel phases or in the rare-earth nickel borocarbides

Coupled SDW and Superconducting Order in FFLO State of CeCoIn5_5

The mechanism of incommensurate (IC) spin-density-wave (SDW) order observed in the Flude-Ferrell-Larkin-Ovchinnikov (FFLO) phase of CeCoIn$_5$ is discussed on the basis of new mode-coupling scheme among IC-SDW order, two superconducting orders of FFLO with B$_{1{\rm g}}$ ($d_{x^{2}-y^{2}}$) symmetry and $\pi$-pairing of odd-parity. Unlike the mode-coupling schemes proposed by Kenzelmann et al, Sciencexpress, 21 August (2008), that proposed in the present Letter can offer a simple explanation for why the IC-SDW order is observed only in FFLO phase and the IC wave vector is rather robust against the magnetic field.Comment: 3pages, 1 figure, accepted for publication in J. Phys. Soc. Jpn., Vol.77 (2008), No.1

A Portable Implementation on Industrial Devices of a Predictive Controller Using Graphical Programming

This paper presents an approach for developing an Extended Prediction Self-Adaptive Controller employing graphical programming of industrial standard devices, for controlling fast processes. For comparison purposes, the algorithm has been implemented on three different FPGA (Field Programmable Gate Arrays) chips. The paper presents research aspects regarding graphical programming controller design, showing that a single advanced control application can run on different targets without requiring significant program modifications. Based on the time needed for processing the control signal and on the application, one can efficiently and easily select the most appropriate device. To exemplify the procedure, a conclusive case study is presented