The geotechnical systems are often studied analysing the response of scaled models in 1-g or n-g devices. A crucial aspect in these kind of models is the capability to read the real response of the system using different instrumentations. In this paper are described the main devices used for the interpretation of the dynamic response of a scaled geotechnical model tested at the Bristol Laboratory for Advanced Dynamics Engineering (BLADE) of the University of Bristol, UK, within the framework of the Seismic Engineering Research Infrastructures for European Synergies (SERIES), funded by the 7th FP of the European Commission. The model is formed by a group of five piles embedded in a bi-layer deposit with different pile head conditions, different dynamic properties of the superstructure (connected at the top of the pile group) and input motions. After some details about the whole experimental campaign and the devices used, the paper shows the main procedures adopted to evaluate the response of the whole system in terms of acceleration, displacement and stresses (only for piles).

This contribution proposes a method to measure the magnetization of ferromagnetic thin-film samples subjected to mechanical stress. We present our Vector Vibrating Sample Magnetometer and two fixtures that enable the adjustable bending of the ferromagnetic samples during the magnetization measurement. The bending, in turn, results in internal stresses. According to the magnetoelastic effect, the magnetization of ferromagnetic materials depends on internal mechanical stress. Results of two Fe49 Co49 V2 samples are shown which prove the applicability of the proposed method.

Underwater wireless sensing systems are envisioned for stand-alone applications and as an addition to cabled observatory systems such as the OBSEA marine observatory. Therefore, this work presents a solution on how to generate power for marine wireless sensors using underwater motion energy. In this pare it is described a prototype based on a Bristol cylinder which can generate electrical voltage using piezoelectric bimorphs. Collecting water motion energy using piezoelectric energy harvesting is particularly difficult due to the mismatch between the low frequency of water kinetics and the highfrequency requirements of piezoelectric transducers. Therefore, to achieve frequency up-conversion we propose the use of the plucking technique applied to piezoelectric energy harvester.. Experimental results show that the proposed energy harvester achieves a maximum power density of 350μW/cm3.

Wideband current transducers with a voltage output are often used to measure AC currents at frequencies up to 1 MHz. The ratio of output voltage to primary current as a function of frequency is the calibration result of these transducers. A traceable method to measure 1 A alternating current at frequencies of 100 kHz and 1 MHz is reported in this paper. The ratio of the wideband current transducer is obtained with expanded uncertainties of 1.3 % for 1 A, 100 kHz and of 2.0 % for 1 A, 1 MHz.

The article describes one of the solutions for improving the accuracy of synchronized measurement for electrical grids using sigma-delta ADC measuring systems. Key problems and their solutions are analyzed. A description is given for the developed algorithm and its implementation in FPGA on National Instruments cRIO platform. The voltage and current measurements were conducted on the NI 9225 and NI 9227 modules respectively. Synchronization is provided by the PPS signal, which is generated by a S.E.A. 9472 GPS receiver module. The essence of the proposed method consists of clocking the NI 9225 and NI 9227 modules by created in the FPGA software clock generator at the frequency of 12.8 MHz. This generator is based on the internal 200 MHz FPGA clock and synchronized to UTC by a PPS signal. The accuracy of the synchronization was experimentally confirmed by measuring the voltage via two identical measuring systems and comparing the results.