251 research outputs found
An architectural generative design process
The paper discusses about architectural and urban design tools, and reports a prototype of parametric application that allows the designer to handle the architectural shape by using urban regulations. It is a Decision Support System (DSS), useful at the early stage of city planning as well as at the early stage of architectural design. The System integrates two different research topics: modelling in geo-referenced environment and modelling through constraints. Compared to the related works (Building Modelling on geo-referenced environment), our application is the first Generative System based on the urban regulation. Three case studies are presented to test the System
Application of a Multiphase Interleaved DC-DC Converter for Power-To-Hydrogen Systems
Power electronics plays a crucial role in the implementation of a clean hydrogen production system, whose last stage consists of a water electrolyzer requiring a DC power supply to be in operation. The most recent architectural solutions imply the use of an isolated DC-DC converter, collecting energy from medium voltage (MV) and delivering it to the electrolyzer. An equivalent electrical model of the electrolyzer is therefore needed, as well as an accurate design of the power converter stage, aiming at a high-efficiency operation of the electrolyzer's cells and at a low-ripple supply current, to avoid premature degradation. This work investigates a full-bridge step-down isolated DC-DC converter, focusing on the opportunity of a multiphase interleaved configuration, particularly convenient for the proposed application. The considered maximum power level is 400 kW, representing a small-scale example of an industrial water electrolyzer supplied by a maximum DC voltage of 700 V. Input DC voltage is 7 kV. Power electronics' simulation have been carried out, as well as model analysis of the proposed converter
Design and realization of a bidirectional full bridge converter with improved modulation strategies
In this paper a Full-Bridge Converter (FBC) for bidirectional power transfer is presented. The proposed FBC is an isolated DC-DC bidirectional converter, connected to a double voltage source—a voltage bus on one side and a Stack of Super-Capacitors (SOSC) on the other side. The control law aims at the regulation either of the bus current (when the load requires power) or of the SOSC current (when the stack requires a recharge). Analysis and design of the proposed FBC are discussed. A Phase Shift Modulation (PSM) scheme is proposed, along with an improved modulation variant for the efficiency optimization, through a proper reduction of the transformer power losses. The realized prototype, compliant with automotive applications, is presented and experimental results are highlighted. The target power level is 2 kW
Automotive Battery Charging based on Efficient Capacitive Power Transfer
Isolated power converters find application in different fields of electric mobility, such as battery charging, where galvanic insulation between on-board storage system and electrical grid is required. Conventional isolated systems are based on the use of transformers, which have the drawback to be bulky and expensive. Nevertheless, insulation implemented by capacitances can be attractive due to the recent technological advances, contributing to increasingly compact, cheap and efficient converters. In this paper, an isolated power converter based on capactive power transfer (CPT), along with the switched capacitor concept, is proposed. GaN FETs are employed as switching power devices in order to handle high operation frequencies with limited power losses. In this work a 500 kHz switching frequency has been selected, with notable benefits brought to the overall power converter in terms of compactness. The developed prototype has been experimentally tested according to a target power level of 3 kW, to prove the proper operation of the proposed converter. The experimental tests have demonstrated a power transfer efficiency as high as 95%
Curcumin loaded polymeric vs. Lipid nanoparticles: Antioxidant effect on normal and hypoxic olfactory ensheathing cells
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
Stability-Centric Design of a Droop-Mounted Adaptive Nonlinear Control for EV Charging in DC Microgrid
This paper presents a streamlined two-layer control system for effective power sharing and switching control in a DC microgrid designed for electric vehicles. The system integrates Energy Storage Systems and advanced converters to ensure a broad operational range and bidirectional power flow. The Dual active bridge topology is used to integrate the EV to DC MG. Hence, the DC MG system has multiple power converter operating simultaneously. The enhanced droop control strategy is advised for the upper layer and the switching controller is derived using nonlinear controls theory embedding the barrier functions. The enhanced droop strategy shares the power considering the individual dynamics of the storage devices while Barrier-based sliding mode control is applied to converters for current/voltage tracking. Mathematical analysis, leveraging Lyapunov's theory, confirms the large signal stability of the system. Demonstrated through MATLAB/Simulink-based simulations, the control system exhibits proficient load power sharing, and the adaptive nonlinear controller showcases robustness against unforeseen disturbances. Moreover, the comparative analysis provides insight into the performance of the proposed control methods concerning traditional methods. Hardware-in-loop tests, utilizing Typhoon HIL 404, authentically validate the real-time performance of the proposed control strategies. Different EV and Constant Power Load scenarios ensure a thorough examination, supporting the efficacy of the system. The study contributes valuable insights into the feasibility and efficiency of these control strategies, paving the way for advancements in sustainable electric mobility
Geo-visual analytics for urban design in the context of future Internet
The internet, where much of the information has
reference to location, together with the latest generation of geographical web services, represent a very large information space that can be used for planning and design. The wealth of information accessible, which requires new forms of interaction and management of the data available, has brought in recent year to the growth of the domain of visual analytics.
In addition, the availability of 3D geobrowsers provides the technological means for interactive 3D environments which can be used to access large-scale geographical information.
This technological scenario is paving the way to 3D webbased, geo-visual analytics tools for land planning and urban design tools.
This paper illustrates the results of a research
effort which has brought to the development of an interactive geo-visual analytics platform for land planning and urban design which makes use of procedural modelling algorithms
Experimental study on B-spline-based modulation schemes applied in multilevel inverters for electric drive applications
This work presents the design, simulation, and experimental validation of new B-Spline-based modulation techniques applied to a Multilevel Power Inverter (MPI), particularly focusing the attention on the harmonic content of the output voltages of the inverter. Simulation and experimental results are proposed and discussed, mainly describing the potential benefits, such as the increase of the multi-level operation of the converter, and drawbacks (low-order harmonics) related to the adoption of B-Spline functions for multilevel inverters applied in the field of electrical drives
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