To gain a better understanding of the surfaces of planets and small bodies in the solar system, the flow behavior of granular material for various gravity levels is of utmost interest. We performed a set of reduced-gravity measurements to analyze the flow behavior of granular matter with a quasi-2D hourglass under coarse-vacuum conditions and with a tilting avalanche box. We used the Bremen dro...

Seismic signals generated by avalanches have been studied by the avalanche team of the Universitat de Barcelona since 1994. The aim of the study is to understand the avalanche seismic signals in relation to their sources to obtain information on the avalanche dynamics and hence use seismic measurements for monitoring purposes. To this end, experiments focused on improving the knowledge of seism...

In this paper we examine nonradiative processes ~cross relaxation and energy migration! vital for the generation of blue avalanche emission in Tm:LiYF4 crystals subjected to radiation near 648 nm. Time-domain and temperature-dependent measurements indicate that two sequential cross-relaxation processes dominate the nonradiative decays of the G4 and H4 excited states in this crystal. The occurre...

When using avalanche photodiodes (APDs) in applications, temperature dependence of avalanche breakdown voltage is one of the performance parameters to be considered. Hence, novel materials developed for APDs require dedicated experimental studies. We have carried out such a study on thin Al1-x Ga x As0.56Sb0.44 p-i-n diode wafers (Ga composition from 0 to 0.15), plus measurements of avalanche g...

This paper deals with the origin of Pretare clastic deposit (PRA), which crops out along Morricone fluvial valley in Central Apennines Italy. With aim deciphering genesis PRA deposit, geological s.l. and geomorphological analyses were carried allowing for interpretation as a rock avalanche. Furthermore, cross sections constrained by well-log field survey data, together stratigraphic, sedimentol...

Snapback breakdown is the second order effect of avalanche breakdown in a device. Snapback occur when the excess supply voltage and high currents created flow through the device and become unstable. These two breakdowns are used to explain the concept of Vertical Impact Ionization MOSFET (IMOS) in its Equivalent Circuit Model. The equivalent circuit model design consists of MOS transistors that...

Single-photon detectors (SPDs) are the most sensitive instruments for light detection. In the near-infrared range, SPDs based on III–V compound semiconductor avalanche photodiodes have been extensively used during the past two decades for diverse applications due to their advantages in practicality including small size, low cost and easy operation. In the past decade, the rapid developments and...

We study a model of “organized” criticality, where a single avalanche propagates through an a priori static (i.e., organized) sandpile configuration. The latter is chosen according to an i.i.d. distribution from a Borel probability measure ρ on [0, 1]. The avalanche dynamics is driven by a standard toppling rule, however, we simplify the geometry by placing the problem on a directed, rooted tre...