1,802 research outputs found

    Random wave run-up with a physically-based Lagrangian shoreline model

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    n the present paper the run-up of random waves was calculated by means of a numerical method. In situ measurements based on a video imaging technique have been used for the validation of the present numerical model. The on-site run-up measurements have been carried out at Lido Signorino beach, near Marsala, Italy,along a transect, normal to the shore. A video camera and a linear array of rods have been used to obtain field data. Numerical simulations with a 1DH Boussinesq-type of model for breaking waves which takes into account the wave run-up by means of a Lagrangian shoreline model have been carried out. In such simulations random waves of given spectrum have been propagated in a numerical flume having the same beach slope of the measured transect. The comparison between registered and estimated run-up underlined an acceptable agreement. Indeed, the numerical model tends to underestimate the actual R2%, with the maximum underestimate being less than 24%, which is a reasonable error in many cases of engineering interest

    Curcumin loaded polymeric vs. Lipid nanoparticles: Antioxidant effect on normal and hypoxic olfactory ensheathing cells

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    Background: Curcumin (Cur) shows anti-inflammatory and antioxidant effects on central nervous system diseases. The aim of this study was to develop Cur-loaded polymeric and lipid nanoparticles for intranasal delivery to enhance its stability and increase antioxidant effect on olfactory ensheathing cells (OECs). Methods: The nanosuspensions were subjected to physico-chemical and technological evaluation through photon correlation spectroscopy (PCS), differential scanning calorimetry (DSC) and UV-spectrophotometry. The cytotoxicity studies of nanosuspensions were carried out on OECs. A viability test was performed after 24 h of exposure of OECs to unloaded and curcumin-loaded nanosuspensions. The potential protective effect of Cur was assessed on hypoxic OECs cells. Uptake studies were performed on the same cell cultures. Thermal analysis was performed to evaluate potential interaction of Cur with a 1,2-Dimyristoyl-sn-glycero-3-phosphocholine (DMPC) biomembrane model. Results: PCS analysis indicated that lipid and polymeric nanosuspensions showed a mean size of 127.10 and 338.20 nm, respectively, high homogeneity and negative zeta potential. Incorporation of Cur into both nanocarriers increased drug stability up to 135 days in cryoprotected freeze-dried nanosuspensions. Cell viability was improved when hypoxic OECs were treated with Cur-loaded polymeric and lipid nanosuspensions compared with the control. Conclusions: Both nanocarriers could improve the stability of Cur as demonstrated by technological studies. Biological studies revealed that both nanocarriers could be used to deliver Cur by intranasal administration for brain targeting

    H-Bridge Converter as Basic Switching Topology Workbench in Power Electronics Teaching

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    This article deals with an effective power electronics learning setup based on a Full-Bridge converter used to teach electrical energy conversion experimentally. In the proposed learning by doing methodology, the hardware and the software are properly mixed in order to obtain an easy-to-use experimental learning environment. In this paper, the H-Bridge is the fundamental brick to build students’ knowledge on the main topics of power electronics converter circuit in different operative conditions. This H-Bridge comes with a reconfigurable output LCL to achieve several basic DC-DC powerconverters topologies. Converter current and voltage switching behavior can be investigated using the proposed setup. Furthermore, the friendly hardware and software set-up allows studying the converter modulation and control techniques of the different power electronics circuits

    Cascaded multilevel inverter for vertical stabilization and radial control power supplies

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    This paper presents the analysis and topology selection for the power supplies of the two DTT equatorial in-vessel coils for plasma vertical stabilization and fast radial control. The physics requirements and assumptions are analyzed in order to identify the system specifications. Since the basic configuration with two independent power supply circuits is too vulnerable to fast plasma events as disruptions, a circuit configuration including both coils is introduced. Two successive solutions, with three or two power converters, are proposed to supply such a common circuit. The adopted topology, based on cascaded H-bridge converters with IGBTs, is simulated by means of a simplified circuital model, that also consider the plasma disruptions. The simulation results show that vertical stabilization and fast radial control functions can be simultaneously achieved with two identical power converters and a passive imbalance branch by using a specific current control scheme
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