Using CORSIKA simulations of the highest energy extensive air showers we show that all showers are similar when described by the shower age parameter: the angular and energy spectra of electrons at a given level in the atmosphere depend only on the shower age at this level. Moreover, electrons with a given energy have the same angular distributions at any level (age) of the shower. We have calculated these distributions and found analytical functions describing them quite well. The total number of particles can also be described in a simple way as a function of age by two halves of a Gaussian function with the widths, however, fluctuating from one shower to another. The description of large showers in terms of age (instead of depth in the atmosphere) is very useful in interpreting data from experiments observing fluorescence light, with admixture of Cherenkov, induced by the showers in the air.

Carefully controlled conditions of evaporation allow the preparation of epitaxial layers of pure AgBr. The temperature dependence of the conductivity of layers with varying thickness is measured. This in principle makes possible the splitting of the conductance into surface and bulk components. The bulk conductivity of the layers is found to be practically identical with that of pure large single crystals of AgBr, which until now has not been observed. For the first time considerable surface conductance is directly observed not only for {111} but for {200} layers too. All parameters characterizing the Frenkel disorder in the subsurface region are evaluated from 150 °C down to room temperature.

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We performed a PDB-wide survey of proteins to assess their cavity content, using the SPACEBALL algorithm to calculate the cavity volumes. In addition, we determined the hydropathy character of the cavities. We demonstrate that the cavities of most proteins are hydrophilic, but smaller proteins tend to have cavities with hydrophobic walls. We propose criteria for distinguishing between cavities and pockets, and single out proteins with the largest cavities.

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