Search results for "conversion"
showing 10 items of 707 documents
A corrosion study of austenitic and martensitic steels under boiler conditions by means of 57Fe conversion electron mössbauer spectroscopy
1978
Abstract The growth of protective oxide layers on a martensitic FeCr (1.4122) and two austenitic FeCrNi steel samples (1.4550 and Incoloy 800) was studied by means of the 57Fe Conversion Electron Mossbauer Spectroscopy (CEMS). Scanning electron microscopy was applied to characterize the topographical nature of the oxide layers. Following a technical procedure of running-in steam generators, the steel specimens were oxidized in oxygen-free water at 295°C, 142 bar and a pH value between 9 and 10 for periods up to 70 h. In the case of the steels 1.4122 and 1.4550 the only oxide phase detected was non-stoichiometric magnetite, whereas nickel ferrite of nonstoichiometric composition was found…
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.
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.
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.
Atomic Layer Deposition of Spinel Lithium Manganese Oxide by Film-Body-Controlled Lithium Incorporation for Thin-Film Lithium-Ion Batteries
2013
Lithium manganese oxide spinels are promising candidate materials for thin-film lithium-ion batteries owing to their high voltage, high specific capacity for storage of electrochemical energy, and minimal structural changes during battery operation. Atomic layer deposition (ALD) offers many benefits for preparing all-solid-state thin-film batteries, including excellent conformity and thickness control of the films. Yet, the number of available lithium-containing electrode materials obtained by ALD is limited. In this article, we demonstrate the ALD of lithium manganese oxide, LixMn2O4, from Mn(thd)3, Li(thd), and ozone. Films were polycrystalline in their as-deposited state and contained le…
A 9-level three-phase multilevel converter with harmonic mitigation and integrated battery balancing
2019
In this paper, a 9 level three-phase multilevel converter with a harmonic mitigation control method and an integrated battery balancing algorithm for automotive purpose is proposed. Each level of the converter is composed by a buck-boost converter and an h-bridge in cascaded connection. The control algorithm is implemented to achieve the harmonic mitigation on the output voltage waveform and to maintain the battery input voltages balanced. The design and operation of the system is described, and simulation study is reported using Matlab/Simulink platform.
Highly Efficient Capacitive Galvanic Isolation for EV Charging Stations
2022
This paper proposes an isolated Switched Capacitor (SC) power converter which provides galvanic isolation through Capacitive Power Transfer (CPT). The combination of these two technologies might answer for electrical and power requirements in different electrical mobility application fields, such as battery charging. Accordingly, due to the low conversion losses the combination of these two technologies can provide, compact, cost effective and highly efficient power converters can be derived, thus potentially answering the scalability requirements for the Electric Vehicles (EV) market. To assess the operation of the proposed circuital solution, a Full Bridge (FB) CPT isolated interfacing co…
Highly Compact Partial Power Converter for a Highly Efficient PV-BESS Stacked Generation System
2022
The inherently intermittent nature of photovoltaic (PV) energy has brought increasing interest towards the integration between PV sources and Battery Energy Storage Systems (BESS). In this paper, a Series Partial Power Processing (PPP) converter based on Capacitive Power Transfer (CPT) is proposed to integrate PV and BESS in a grid-connected inverter system. The proposed converter has been simulated according to a PV string capable to provide 1430 W under full irradiance conditions, a BESS nominal voltage equal to 215 V and a solar inverter assumed to operate with a minimum voltage of 150 V and a maximum current of 10 A. Simulation tests carried out at different conditions of solar radiatio…
Synthesis and photovoltaic performance of the porphyrin based sensitizers with 2H-[1,2,3]triazolo[4,5-c]pyridine and benzotriazole as auxiliary accep…
2017
Abstract Two novel zinc porphyrin dyes containing either benzotriazole or 2 H -[1,2,3]triazolo[4,5- c ]pyridine as auxiliary acceptors, respectively, were synthesized for dye-sensitized solar cells. These two auxiliary acceptors were firstly applied into porphyrin based dyes. The photophysical and electrochemical properties of the dyes were investigated. These two dyes show the whole visible light absorption when they are adsorbed on the TiO 2 film, which means that they are promising sensitizers for dye-sensitized solar cells. The absorption intensity of the triazolopyridine containing dye is higher than that of the benzotriazole containing dye, resulting in a better light harvesting. Thus…
Conversioni nel Vicino Oriente Ottomano e diffusione del cattolicesimo a Betlemme
2009
L'articolo analizza la diffusione del Cattolicesimo nel villaggio di Betlemme durante il XII secolo