Self-organized criticality induced by quenched disorder: experiments on flux avalanches in NbHx_x films

We present an experimental study of the influence of quenched disorder on the distribution of flux avalanches in type-II superconductors. In the presence of much quenched disorder, the avalanche sizes are power-law distributed and show finite size scaling, as expected from self-organized criticality (SOC). Furthermore, the shape of the avalanches is observed to be fractal. In the absence of quenched disorder, a preferred size of avalanches is observed and avalanches are smooth. These observations indicate that a certain minimum amount of disorder is necessary for SOC behavior. We relate these findings to the appearance or non-appearance of SOC in other experimental systems, particularly piles of sand.Comment: 4 pages, 4 figure

Sensor High Throughput Screening Using Photocurrent Measurements in Silicon

AbstractA new high throughput screening method to characterise alloys used as gate metal of Metal/solid Electrolyte/Insulator/Semiconductor (MEIS) gas-sensors was developed. Samples with continuous gradients in alloy concentration for the system Pd1-x-yNiyCoy were analysed regarding H2 sensitivity. First results showed reduced poisoning effects of H2S for Ni concentrations between 4-11 at-% in Pd

Early forest fire detection using low-energy hydrogen sensors

Most huge forest fires start in partial combustion. In the beginning of a smouldering fire, emission of hydrogen in low concentration occurs. Therefore, hydrogen can be used to detect forest fires before open flames are visible and high temperatures are generated. We have developed a hydrogen sensor comprising of a metal/solid electrolyte/insulator/semiconductor (MEIS) structure which allows an economical production. Due to the low energy consumption, an autarkic working unit in the forest was established. In this contribution, first experiments are shown demonstrating the possibility to detect forest fires at a very early stage using the hydrogen sensor

Comparison of physical and biogeochemical parameters of the tidal inlets Otzumer Balje (Langeoog and Spiekeroog) and Harle (Spiekeroog and Wangerooge), Wadden Sea, Southern North Sea

The data-set was obtained in the German North Sea with RB Otzum (ICBM) between the East Frisian Islands Spiekeroog and Langeoog on March 3rd 2020 and between the islands Wangerooge and Spiekeroog on March 4th 2020. Conductivity, temperature, pressure and oxygen concentration were measured with a Seabird CTD (type 19plusV2). Oxygen saturation, temperature, salinity, turbidity and concentrations of Chlorophyll a and CDOM at the surface were measured by a Ferry Box (type 4H Jena Engineering). Sediment samples were taken with a Van-Veen-Grapple and phytoplankton samples were trawled with a plankton net. The weather data were obtained from the Time Series Station Spiekeroog (ICBM). On both days sampling took place for half a tidal cycle from ebb current peak until the maximum of the flood current. Transects contained three stationary CTD profiles at the boundaries and at the center of appropriate inlet. To investigate the impact of the groin located at the Harle inlet, two transects were sampled in the northern area of the groin and four transects south of the groin. The CTD was veered with a speed of around 0.1 m/s while the boat was drifting with the current. The downcast profiles were binned to regular 0.25 m intervals. The timestamps of all data sets are given in UTC