The European Physical Journal Special Topics

Experiments in the field of high energy physics make use of very complex detector systems. Extraction of meaningful results from these experiments needs a deep understanding of the detector performance. The most important tool in the process of understanding is the use of simulation of some known physics processes. Tools were being developed from late 1970s with more and more improved modeling of electromagnetic and strong interaction of particles with matter. These tools are also used to design a detector system of present day high energy physics experiment. Design and construction of detectors for the experiments at the Large Hadron Collider (Lhc) took nearly two decades. Detector simulation played an important role in these designs. One of the most important toolkits and its use in one of the experiments at the Lhc are described in this paper.

We briefly describe the motivation for the special issue on ’Role of symmetries in Nuclear Physics’. In addition, we also present an overview of the topics covered in this special issue.

In this paper we presented a image encryption based on permutation-substitution using chaotic map and Latin square image cipher. The proposed method consists of permutation and substitution process. In permutation process, plain image is permuted according to chaotic sequence generated using chaotic map. In substitution process, based on secrete key of 256 bit generate a Latin Square Image Cipher (LSIC) and this LSIC is used as key image and perform XOR operation between permuted image and key image. The proposed method can applied to any plain image with unequal width and height as well and also resist statistical attack, differential attack. Experiments carried out for different images of different sizes. The proposed method possesses large key space to resist brute force attack.

In this work we report on a novel concept for the preparation of gas selective composite membranes by a simple and robust synthesis protocol involving a controlled in-situpolycondensation of functional alkoxysilanes within the pores of a mesoporous ceramic matrix. This innovative approach targets the manufacture of thin nanocomposite membranes, allowing good compromise between permeability, selectivity and thermomechanical strength. Compared to simple infiltration, the synthesis protocol allows a controlled formation of gas separation membranes from size-adjusted functional alkoxysilanes by a chemical reaction within the mesopores of a ceramic support, without any formation of a thick and continuous layer on the support top-surface. Membrane permeability can thus be effectively controlled by the thickness and pore size of the mesoporous layer, and by the oligomers chain length. The as-prepared composite membranes are expected to possess a good mechanical and thermomechanical resistance and exhibit a thermally activated transport of He and H2 up to 150 °C, resulting in enhanced separation factors for specific gas mixtures e.g. FH2/CO ∼ 10; FH2/CO2 ∼ 3; FH2/CH4 ∼ 62.

This paper describes nonlinear ion transport properties of liquid and solid electrolytes. Typically, the relation between ionic current density and electric field becomes nonlinear at electric fields above 50–100 kV/cm. We review the 1st and 2nd Wien effect found in classical strong and weak electrolyte solutions as well as the strong nonlinear ion transport effects observed for inorganic glasses and for polymer electrolytes. Furthermore, we give an overview over models describing nonlinear ion transport in electrolyte solutions, in glasses and in polymers. Recent results are presented for the nonlinear ionic conductivity of supercooled ionic liquids. We show that supercooled ionic liquids exhibit anomalous Wien effects, which are clearly distinct from the classical Wien effects. We also discuss the frequency dependence of higher-order conductivity and permittivity spectra of these liquids.

Diffusion in anisotropic samples is often studied by quasi-elastic neutron scattering at time-of-flight (t-o-f) instruments. During the data analysis the measured dynamic structure factor S(Q,E) is fitted by a model function, which - reflecting the anisotropy of the sample - depends on the sample orientation. The error introduced in this way will be discussed. Correct measurements can be performed for such cases at a triple axis spectrometer, where energy scan can be performed for a certain Q vector fixed to the sample orientation. Clays show 2D anisotropy in the structure, which is supposed to be visible also in the diffusion of water located between the clay sheets. A first experiment performed on TASP (SINQ) will be shown.