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In this paper, seismic vulnerability appraisement, restoration, and consolidation plan of a 17th century masonry building (Rossi farm) with cultural and artistic value located in a small city near Naples are reported and discussed. This case study is presented and described, providing historical data and information about its actual conditions, spaces, functions and structures. Once the crack pattern detected in the building has been appropriately traced, the knowledge is deepened by performing all the three seismic risk assessment analyses proposed by the “Italian Guidelines for the assessment and reduction of seismic risk of cultural heritage". The first evaluation level is a qualitative and simplified tool allowing for the knowledge of the risk level of the building under study. Afterwards, the structure has been subjected to more accurate investigations dealing with its local mechanisms and global behaviour in the second and the third evaluation levels, respectively. In all three analysis phases, the results have shown the high vulnerability of the masonry farm. Based on these results, a consolidation plan, according to the Cultural Heritage Italian Guidelines suggestions, has been proposed.

Vertical leakage in lateral GaN devices has a significant contribution to the overall off-state current at high blocking voltages and high temperatures. It could could lead to premature breakdown before avalanche or dielectric breakdown occur. This paper identifies via experimental results and TCAD simulations the main physical mechanisms responsible for the vertical leakage through the epi and transition layer structure: (i) silicon impact ionization, (ii) electron injection across the AlN nucleation layer/silicon interface, (iii) space charge limited current. In particular, the trap-to-trap model, accounting for the leakage current across the nucleation layer, was implemented showing to be dominant at lower voltages (

© 2017 by the author. With Gallium Nitride (GaN) device technology for power electronics applications being ramped up for volume production, an increasing amount of research is now focused on the performance of GaN power devices in circuits. In this study, an enhancement mode GaN high electron mobility transistor (HEMT) is switched in a clamped inductive switching configuration with the aim of investigating the source of oscillatory effects observed. These arise as a result of the increased switching speed capability of GaN devices compared to their silicon counterparts. The study identifies the two major mechanisms (Miller capacitance charge and parasitic common source inductance) that can lead to ringing behaviour during turn-off and considers the effect of temperature on the latter. Furthermore, the experimental results are backed by SPICE modelling to evaluate the contribution of different circuit components to oscillations. The study concludes with good design techniques that can suppress the effects discussed.

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The metabolic syndrome term is generally used to define the co-presence of risk factors responsible for an important increase of cardiovascular diseases incidence in patients with overweight, obesity, hypertension and type II diabetes mellitus. Long the history of such syndrome, if it is considered that already in the 50's the Framingham study's first observations concluded that the presence of more factors was increasing the relative risk of cardiovascular events (Ictus, myocardial infarct, death, etc.) in an exponential way. In 1988 Reaven coined the X syndrome term, recognizing this entity like a multiple and independent risk factor for cardiovascular disease. A recent report of the National Cholesterol Education Programme Adult Treatment Panel (NCEPT-ATP III) has identified the metabolic syndrome as an independent risk factor for cardiovascular disease and considers it like tightening indication for an intense modification of the life style. Currently there are three definitions more commonly recognized, as the one suggested by the World Health Organisation (WHO), by the European Group For The Study Of insulin Resistance (EGIR) and the National Cholesterol Education Programme Adult Treatment Panel (ATP III). In all cases a central role has the hypertension. In fact, beyond the differences in the definition and the emergency of the so-called new risk factors, all of metabolic, proinflammatory and prothrombotic nature, it has to point out that the hypertension is a constant in all the definition, reaching the prevalence of 100% in the metabolic syndrome of the elderly. The prevalence of the syndrome increases with the age and is present in almost half of the over 60 population. In particular, it increases from 6.7% in patients with 20-29 years to 43% in the over 70. In both sexes the prevalence quickly increases after the third decade of life, reaching a peak between the 50 and 70 years in the men and the 60-80 years in the women. Regarding to the pathogenesis of the hypertension in subjects with metabolic syndrome: the hyperinsulinemia secondary to insulin-resistance seems to play an important role determining both the stimulation of the sympathetic nervous system, with consequent vasoconstriction, and the retention of sodium, responsible of increase in arterial blood pressure values, such to antagonize the vasodilator effects of the insulin. In particular, the chronic hyperinsulinemia associated to the metabolic syndrome could modulate the renal sodium excretion, since it has been shown that such hormone is able to regulate the reabsorption of the sodium at tubular level or to increase the Sodium/Hydrogen pump by renal tubuli. As regards the management of this disease, the necessity of a treatment to 360° of the metabolic syndrome in its entirely and of its single aspects, included the hypertension, seems not questionable. However, we have to point out the necessity of a particular attention both of the doctor and the patient in the management of the polipharmacotherapy that, in the elderly, is a clear risk factor for the iatrogenic damage. Probably, the engagement of the doctors to choose drugs with pharmacocinetic and pharmacodinamic profiles more appropriates to the total treatment of the syndrome and their ability to induce a stable modification of the life style will make surer and more effective the management of such syndrome also in the elderly subject.