In this work a topology optimization procedure is proposed and applied to the TEAM 25 problem, i.e. a model of a die press with electromagnet for orientation of magnetic powder. The shape of the press is described as a free discretized profile, and its relation to the flux density in the cavity is simulated by Finite Element Analysis (FEA) and learned by a Deep Neural Network (DNN) model. The DNN is used as a surrogate model for optimization, aiming to obtain a desired flux density distribution in the cavity. Results are promising, as better accuracy is obtained with respect to full FEA-based optimization approach with reduced time cost. Once trained, surrogate model can be used to efficiently solve a whole family of problems where a different target field distribution is defined.

A short sample of the NbTi cable-in-conduit conductor (CICC) manufactured for the ITER PF insert coil has been tested in the SULTAN facility at CRPP. The short sample consists of two paired conductor sections, identical except for the sub-cable and outer wraps, which have been removed from one of the sections before jacketing. The test program for conductor and joint includes DC performance, cyclic load and AC loss, with a large number of voltage taps and Hall sensors for current distribution. At high operating current, the DC behavior is well below expectations, with temperature margin lower than specified in the ITER design criteria. The conductor without wraps has higher tolerance to current unbalance. The joint resistance is by far higher than targeted.

Nearby lightning strikes are prone to induce overvoltage transients in photovoltaic (PV) modules and in their power conditioning circuitry, which can permanently damage the PV system. Therefore, it becomes important to establish a method for accurate assessment of such transients. To this aim, the authors propose a three‐dimensional (3D) semi‐analytical numerical method to study the electromagnetic transients caused in PV modules by nearby lightning strikes. The approach bases on a semi‐analytical expression of the magnetic vector potential generated by a geometrically complex lightning channel. The proposed method is able to calculate the transient overvoltage in a PV module, both in common and differential‐mode, taking also into account capacitive and inductive couplings between the internal circuit and the PV metallic frame. Both modes are required to design the surge protective devices (SPDs) in PV power systems. Comparing to the models in literature, the proposed approach explicitly considers the complex geometry of the lightning channel. Statistical analysis allows assessing the impact of channel geometry by randomly generating a number of likely lightning paths. Results show that the lightning‐induced overvoltage in a PV module is highly dependent on factors such as distance to the lightning channel and lightning channel geometry.

This paper proposes the analysis of a control loop system employing a Terfenol-D actuator driving a real mechanical load. The aim of the paper is to analyze the performances of such a system when a strategy of hysteresis compensation is employed. Such strategy has demonstrated its effectiveness in simpler feedback systems (with no mechanical load) by improving the tracking error, decreasing the control signal so as to avoid saturation and harmful stress to the actuator. As a consequence, the algorithm allows also to reduce energy losses in the actuator.

The evaluation of salivary biomarkers has been proposed as a simple and non-invasive aid to the conventional periodontal diagnosis based on clinical-radiographic parameters. Matrix metalloproteinase-8 (MMP-8), especially in its active form, is considered one of the most reliable biomarkers of periodontitis, and point-of-care tests (POCTs) have been proposed for its clinical monitoring. In this proof-of-concept study, a novel highly sensitive POCT based on a plastic optical fiber (POF) biosensor exploiting surface plasmon resonance (SPR) to detect salivary MMP-8 is described. A SPR-POF biosensor was functionalized with a specific antibody to develop a surface-assembled monolayer (SAM) for the detection of total MMP-8. A white light source and a spectrometer connected to the biosensor were used to quantify MMP-8 level in both buffer and real matrix (saliva) by analysing the shift of the resonance wavelength determined by the specific antigen-antibody binding upon the SAM. Dose-response curves by serial dilutions of human recombinant MMP-8 were realized, obtaining a limit of detection (LOD) of 40 pM (1.76 ng/ml) in buffer and 225 pM (9.9 ng/ml) in saliva and high selectivity compared to interferent analytes (MMP-2 and IL-6). The proposed optical fiber-based POCT was able to detect and measure total MMP-8 with high selectivity and very low LOD in both buffer and saliva. The SPR-POF technology may be employed to create highly sensitive biosensors to monitor salivary MMP-8 levels. The possibility of specifically detecting its active, rather than total, form need to be further investigated. If confirmed and clinically validated, such a device may represent a promising tool to make an immediate, highly sensitive and reliable diagnosis of periodontitis, and to carry out a timely and targeted therapy, possibly helping to prevent the onset of local and systemic periodontitis-related complications.