Verification of avalanche bulletins by questionnaires

The paper describes how avalanche bulletins (regional and national) are being verified by means of questionnaires in Switzerland. At the beginning of winter 1996/97 a set of four questionnaires has been introduced: • Questionnaire A: "Personal judgement of avalanche danger" • Questionnaire B: "Observations of avalanches without personal or material damage" • Questionnaire C: "Observations of avalanches with people caught but without material damage" • Questionnaire D: "Observations of avalanches with personal and/or material damage" About 10000 of these questionnaires have been distributed to the public, 500 have been returned during the winter 1996/97. This means twice as many returns as for previous winters. Questionnaires B,C and D can be used for the verification of the higher hazard degrees. Questionnaire A is the most frequently returned and can be used for all degrees of hazard. Therefore it is the subject of our evaluation. The questionnaires are used on a daily basis for the construction of the bulletin if they were returned in time. Therefore we cannot talk of an independent verification in a strict sense. At the end of the winter a comparison between questionnaires and bulletins has been done. The questionnaires allow to define a degree of hazard for 8 expositions and 4 height zones (lSOO-2000m, 2000-2S00m, 2500- 3000m and >3000m). Therefore we compare a set of 32 segments of every questionnaire to the bulletin. The overall estimation for Switzerland shows that about 64% of the feedback are in agreement with the bulletin, 32% differ by l degree of hazard and 4% by 2. The symmetric distribution of differences indicates that the degree of hazard is neither systematically over- nor underestimated. The distribution varies heavily between regions, height levels and expositions. For the region Davos a detailed verification using additional own field observations has been done and is compared to the verification based on questionnaires

Transport properties of nano-devices: One-dimensional model study

A 1D model study of charge transport in nano-devices is made by comparing multi-configuration time dependent Hartree-Fock and frozen core calculations. The influence of exchange and Coulomb correlation on the tunneling current is determined. We identify the shape of the tunneling barrier and the resonance structure of the nano-device as the two dominant parameters determining the electron transport. Whereas the barrier shape determines the size of the tunneling current, the resonances determine the structure of the current.Comment: 4 page

Simultaneous double ionization of C60 molecules in single-cycle pulses

We theoretically investigate simultaneous double ionization of C60 Buckminsterfullerene clusters within the strong field approximation, taking into account two-body effects like Coulomb blocking. Our analysis suggests that for infrared single-cycle pulses, simultaneous double ionization becomes comparable in magnitude to sequential double ionization. Additionally, estimates show that Coulomb blocking weakens with increasing cluster size and field strength.Studienstiftung des Deutschen Volkeshttps://doi.org/10.13039/501100004350Peer Reviewe