Search results for " efficiency"
showing 10 items of 1091 documents
How effective are the vegetated surfaces for the CO2 sequestration? Analyzing parameters and methods
2021
Human activities are severe sources of greenhouse gases and, particularly, of CO 2 . This trend, according with the highly demanding criteria released by the international institutions, must be suitably cut, in order of turning the pollutant emissions within limits that will guarantee a sustainable and environmentally safe development of the human species. Apart the measures that are since long time usually implemented in the technological systems, other interventions should be properly adopted in supporting the sustainability of the anthropic activities. These actions mainly apply to the so-called bioclimatic and passive measures and, particularly, could usefully refer to the plantation of…
From the Paper to the Tablet: On the Design of an AR-Based Tool for the Inspection of Pre-Fab Buildings. Preliminary Results of the SIRAE Project
2018
Energy-efficient Buildings (EeB) are demanded in today’s constructions, fulfilling the requirements for green cities. Pre-fab buildings, which are modularly fully-built in factories, are a good example of this. Although this kind of building is quite new, the in situ inspection is documented using traditional tools, mainly based on paper annotations. Thus, the inspection process is not taking advantage of new technologies. In this paper, we present the preliminary results of the SIRAE project that aims to provide an Augmented Reality (AR) tool that can seamlessly aid in the regular processes of pre-fab building inspections to detect and eliminate the possible existing quality and ener…
Assessing the electricity consumption of outdoor lighting systems in the presence of automatic control: The OL-BAC factors method
2020
Abstract Building automation systems are able to influence significantly buildings’ energy performance. The BAC factors method, presented for the first time by the International Standard EN 15232, is the most used and simple instrument for evaluating the impact of such systems in terms of reduction of the electrical and thermal energy consumption of buildings services. Nevertheless, Standard EN 15232 does not take into consideration the automation of lighting systems serving buildings’ external areas like passages, gardens, entrance walkways, etc. In some cases, such areas can be very extended and, as a consequence, responsible for a not negligible percentage of the overall electricity cons…
Model-based optimization of injection strategies for SI engine gas injectors
2014
A mathematical model for the prediction of the mass injected by a gaseous fuel solenoid injector for spark ignition (SI) engines has been realized and validated through experimental data by the authors in a recent work [1]. The gas injector has been studied with particular reference to the complex needle motion during the opening and closing phases. Such motion may significantly affect the amount of injected fuel. When the injector nozzle is fully open, the mass flow depends only on the upstream fluid pressure and temperature. This phenomenon creates a linear relationship between the injected fuel mass and the injection time (i.e. the duration of the injection pulse), thus enabling efficien…
Template electrodeposition and characterization of nanostructured Pb as a negative electrode for lead-acid battery
2019
Abstract Despite Lead Acid Battery (LAB) is the oldest electrochemical energy storage system, diffusion in the emerging sectors of technological interest is inhibited by its drawbacks. The principal ones are low energy density and negative plate sulphating on high rate discharging. In this work, it is shown the possibility of overcoming such drawbacks by using nanostructured lead as a negative electrode. Lead nanowires (NWs) were fabricated by electrochemical deposition in template, which is an easy, cheap, and easily scalable process. Their morphology and crystal structure have been characterized by electron microscopy and X-ray diffraction, respectively. An electrochemical cell simulating…
Wireless battery chargers for portable applications: Design and test of a high-efficiency power receiver
2013
In this study, the authors present a 5 W wireless battery charger for handheld devices. Efficiency-related issues are addressed. A power receiver architecture which improves power conversion efficiency is proposed. Design hints are provided for further applications. Comparison with a conventional architecture is provided as well. Laboratory prototypes of both the proposed and the conventional architectures have been realised. Both prototypes are tested by using the same power transmitter to perform a valuable comparison. As shown by the experimental results, in the receiver side power conversion efficiency is increased up to 99% thanks to the proposed solution.
Efficiency optimization in bi-directional inductive power transfer systems
2015
Inductive Power Transfer (IPT) allows to wirelessly supply electronic devices. Thus, it is a very smart technique of battery charging for electric vehicles. In a parking area scenario, IPT is a proper method aiming at the energy transfer from the vehicle battery to the electric grid too. Bi-Directional Inductive Power Transfer (BDIPT) Systems are an attractive solution for the automotive market. Due to the great relevance of the energy saving problem, the goal of an efficiency maximization is researched by the energy market. In this paper, an in-depth investigation of the power efficiency in BDIPT systems is carried out, aiming at the optimum efficiency.
An over-the-distance wireless battery charger based on RF energy harvesting
2017
An RF powered receiver silicon IC (integrated circuit) for RF energy harvesting is presented as wireless battery charger. This includes an RF-to-DC energy converter specifically designed with a sensitivity of -18.8 dBm and an energy conversion efficiency of â¼45% at 900 MHz with a transmitting power of 0.5 W in free space. Experimental results concerned with remotely battery charging using a complete prototype working in realistic scenarios will be shown.
Sizing of ICE and Lithium-ion battery for series hybrid vehicle over life cycle with battery aging
2013
This paper presents a method to evaluate the volume and weight of the internal combustion engine (ICE) and lithium-ion battery for a series hybrid vehicle that allows to minimize the mean consumption over system life. Individual driving cycles of the car over a total distance of 100 000 km are simulated. The ICE and battery dimensions are approximated; the fuel consumption is evaluated using a general approach. Lithium-ion battery is described including capacity fading and the energy split between ICE and battery system is evaluated using an heuristic approach. Results show a decrease of mean fuel consumption down to 5.1 L/100km.
Wireless battery charging: E-bike application
2013
Nowadays, Inductive Power Transfer (IPT) represents a widely investigated issue with respect to modern battery charging methods, by providing a wireless solution. IPT is applied across a large variety of applications, from Watt to kWatt power levels. Although IPT features great benefits in terms of safety and comfort, the most significant drawback consists of a relatively poor power conversion efficiency. In this paper, a 100W wireless charging equipment for E-bikes which improves efficiency is proposed. Complete magnetic structure design, as well as transmitter and receiver efficient architectures, are deeply exposed. The efficiency of the designed solution is shown by simulation results.