Search results for "Energy engineering"
showing 10 items of 1099 documents
Stabilizing nanostructured lithium insertion materials via organic hybridization: A step forward towards high-power batteries
2014
Abstract Herein, we present the electrochemical characterization of carbon-coated TiO 2 nanorods, obtained by carbonizing RAFT (reversible addition fragmentation chain transfer) polymerization derived block copolymers anchored on anatase TiO 2 nanorods. These carbon-coated TiO 2 nanorods show an improved electrochemical performance in terms of first cycle reversibility, specific capacity, cycling stability, and high rate capability. More importantly, however, the structural disordering observed in the uncoated TiO 2 nanorods by means of galvanostatic and potentiodynamic cycling as well as ex situ XRD analysis, does not occur for the carbon-coated material. Preventing this structural disorde…
Photoelectrochemical characterization of anatase-rutile mixed TiO2 nanosponges
2016
This work studies the influence of using hydrodynamic conditions during anodization on the morphology and electrochemical properties of anatase/rutile mixed TiO2 nanotubes (Reynolds number, Re = 0) and nanosponges (Re > 0). To this purpose different techniques were used, such as: microscopy techniques (Field-Emission Scanning Electron Microscope, FE-SEM, and Confocal Laser-Raman Spectroscopy), Electrochemical Impedance Spectroscopy (EIS), Mott Schottky (MS) analysis and photoelectrochemical water splitting tests. This investigation demonstrates that the morphology of TiO2 nanostructures may be greatly affected due to the hydrodynamic conditions and it can be adjusted in order to increase th…
Generalized power-angle control for grid-forming converters: A structural analysis
2022
Several control schemes have been recently proposed and studied as grid-forming controls for power converters. In all these schemes, the power-angle control loop is the part which defines the fundamental capabilities of the grid-forming control: that control loop governs in fact the inherent synchronization mechanism of the power converter, the power sharing with the other generation sources in the system and the oscillatory characteristics of the converter-based resource. This article introduces a general formulation for the power-angle control characterizing the grid-forming concept for power converters. The generalized power-angle control is based on a polynomial fraction formulation, an…
Addressing Dendritic Cells for Anticancer Immunity
2014
Photocatalytic degradation of dyes by using a membrane reactor
2004
Abstract Dyes are organic compounds used in textile, food and drug industries, and their abatement represents one of the main problems in the treatment processes because generally they are very stable toxic compounds. In this work, two commercial azo-dyes, i.e. Congo Red (C32H22N6Na2O6S2) and Patent Blue (C27H31N2NaO6S2), in aqueous solution were degraded in a photocatalytic membrane reactor by using TiO2 Degussa P25 as the catalyst. Different system configurations and irradiating sources were studied, and the influence of some operational parameters such as the pressure in the membrane cell and the initial concentration of the substrates was determined. A comparison between suspended and e…
Photocatalytic formation of H2 and value-added chemicals in aqueous glucose (Pt)-TiO2 suspension
2016
Abstract Commercial and home prepared bare and Pt-supported TiO2 samples were used as the photocatalysts for the aqueous photo-conversion of glucose at ambient pressure and temperature. Aerobic and anaerobic conditions were used to study the products of glucose degradation both in the liquid (arabinose, erythrose, gluconic acid, glucaric acid, fructose and formic acid) and gaseous (H2 and CO2) phases. The distribution of these molecules was different in the presence of the various powders, depending on the structural and physico-chemical properties of the materials, and Pt resulted essential for the anaerobic production of H2. The home prepared samples resulted more active than the commerci…
Energy management of multi-carrier smart buildings for integrating local renewable energy systems
2016
The proposed paper aims at defining a Building Management System (BMS) able to control energy flows inside a smart building integrated with various energy networks and Renewable Energy Resources (RES). The smart building envisaged in this work interacts with different energy carriers and is equipped with cogeneration and RES systems, as well as storage devices, which enable a certain degree of flexibility in the energy usage. The smart building is modelled as a multi-carrier hub, by defining the graphical and mathematical model of the building system. Moreover, the control criteria of the BMS are explained and the implementation of the BMS itself is depicted, along with some early results. …
Improvement of Energy Efficiency for Indoor Lighting in a Big Shopping Center
2018
As the progressive diffusion of shopping centers in Italy, the paper analysis the potential energy savings in the indoor lighting plant, thanks to new technologies as LED lamps and Building Automation System. The case study, applied to a big shopping mall in the middle of Italy, shows great results, thanks to the high efficiency of LED technology, high number of operating hours and the implementation of a control system. An economic and environmental evaluation is reported.
Deep learning strategies for automatic fault diagnosis in photovoltaic systems by thermographic images
2021
Abstract Losses of electricity production in photovoltaic systems are mainly caused by the presence of faults that affect the efficiency of the systems. The identification of any overheating in a photovoltaic module, through the thermographic non-destructive test, may be essential to maintain the correct functioning of the photovoltaic system quickly and cost-effectively, without interrupting its normal operation. This work proposes a system for the automatic classification of thermographic images using a convolutional neural network, developed via open-source libraries. To reduce image noise, various pre-processing strategies were evaluated, including normalization and homogenization of pi…
History and results of the Riga dynamo experiments
2008
On 11 November 1999, a self-exciting magnetic eigenfield was detected for the first time in the Riga liquid sodium dynamo experiment. We report on the long history leading to this event, and on the subsequent experimental campaigns which provided a wealth of data on the kinematic and the saturated regime of this dynamo. The present state of the theoretical understanding of both regimes is delineated, and some comparisons with other laboratory dynamo experiments are made.