The effect of the frequency on the different parameters of ozone generation in the dielectric barrier discharge (DBD) has been investigated. It is found that at low frequency, ( $f_{0} = 325$  Hz), an electric resonance can be obtained in the electric circuit. The onset voltage, at which the ozone starts to build up, was reduced from 3.25 kV at 50 Hz to 1.57 kV at 325 Hz. The efficiency has been increased from nearly zero at 50 Hz to 232.94 g/kW h at 200 Hz under applied voltage of 2.025 kV.

We propose a Π-shaped circuit model for active metamaterials using periodic circuit structures with series inductors and shunt capacitors (LC) and series capacitors and shunt inductors (CL). Using the circuit model, we develop a general theory for active metamaterials, revealing the role of active components and demonstrating the principle for metamaterials to be active. Byinserting negative and positive resistances in the LC and CL structures, we first attain the active superlens using three slabs of effective media made by such metamaterial circuit structures andshow that the amplitude of voltage will be augmented on two interfaces after adding the active/lossy components. Then we realize the active amplification of evanescent waves and show that thetransmission coefficient will be larger than 0 dB near the resonant frequency, which evidently illustrates the active feature of the medium. Both of these two applications have to satisfy theanti-matching conditions to fulfill the resonance and tunneling effect.

The response matrix of a neutron spectroscopy system is studied. The system is comprised of successive rectangular parallel layers of BF3 followed sequentially by water layers. In total, ten BF3 (96% 10B) layers and nine H2O ones are configured in periodic order. Two different geometries are investigated; system A and system B. MCNP-4C is used to estimate the response functions of both systems. The response matrix of system A shows higher magnitude than those obtained from system B. In addition, the response matrix of system A shows more distinctive behavior than that obtained from system B.

In order to harmonise the communication systems between the train and the railway control centres over the European territory, a GSM-R (Global System for Mobile communications – Railways) communication network is progressively deployed along the European railway network. However, the GSM-R communications on board high speed trains can be disturbed by the transient electromagnetic (EM) disturbances induced by the sliding contact between the catenary and the pantograph. In order to study the immunity of the embedded GSM-R communication system against these transient electromagnetic disturbances, the transient interferences induced on the GSM-R antennas on board trains, were characterised in terms of time and amplitude parameters. Measurement campaigns were carried out in France to collect a large number of induced EM interferences on GSM-R antennas fixed on the train roof. With the ultimate goal of generating transient noise scenarios representative of those detected by the antennas, and performing immunity tests in laboratory, statistical distributions of the characteristics (rise time, time duration, repetition rate, amplitude) of the transients are presented. This paper presents the different steps of the analysis of the transient disturbances and the generation of the transient EM scenarios.