Search results for "Node"
showing 10 items of 1701 documents
Amorphous semiconducting passive film-electrolyte junctions revisited. The influence of a non homogeneous density of state on the differential admitt…
2006
Abstract An analysis of the electronic properties of amorphous semiconductor-electrolyte junction is reported for passive films grown on Nb in alkaline solution and in a large range of thickness (~20nm ÷ ~250nm). A modelling of electronic density of state (DOS) has been carried out by fitting EIS spectra, at different potentials and in a range of frequencies (0.1 Hz ≤ f ≤100 kHz), and differential admittance (DA) data of a-Nb 2 O 5 /El interface. The fitting of EIS and DA curves was performed by using the theory of amorphous semiconductor Schottky barrier and a non-homogeneous DOS distribution.
NANOSTRUCTURED ANODE MATERIAL FOR Li-ION BATTERY OBTAINED BY GALVANIC PROCESS
2016
The accumulation of energy by batteries plays a fundamental role for the production of electrical energy and for its efficient management. Between different storage systems the lithium-ion battery are considered very interesting. Although they are now a well-established commercial reality, they are still subject of vigorous research efforts, in order to make improvements primarily in terms of costs, safety and energy density. The latter is in fact still low compared to that of fossil fuels, if you think to the automotive field. In particular efforts are focused towards the identification of valid alternatives to the electrode materials so as to overcome the limitations and extend the use of…
Nanostructured anode and cathode materials for Li-ion batteries
2010
Sn-Co nanowire-based anodes for lithium-ion batteries
2010
The demand of improvement in lithium-ion battery technology in terms of specific capacity and safety has stimulated the search for anode materials alternative to graphite. Among them, tin-based materials have been widely studied because tin can intercalate lithium up to atomic ratio Li/Sn of 4.4 to deliver a impressive specific capacity of 993 mAhg−1 (while graphite gives 372 mAhg−1). Unfortunately the high volume change of about 300%, which is related to the insertion/removal of lithium, causes the alloy pulverization and loss of electric contact that causes a poor cycle life. The synthesis of nanometric materials, intermetallic compounds and carbon composites are strategies that have been…
Nanostructured binary tin alloy fabrication
2010
Elettrodeposizione di leghe nanostrutturate a base di stagno
2010
Control of a Non-isothermal CSTR by Type-2 Fuzzy Logic Controllers
2009
The paper describes the application of a type-2 fuzzy logic controller (FLC) to a non-isothermal continuous stirred tank reactor (CSTR) characterized by the presence of saddle node and Hopf bifurcations. Its performance is compared with a type-1 fuzzy logic controller performance. A full analysis of the uncontrolled CSTR dynamic was carried out and used for the feedback-feedforward fuzzy controllers development. Simulation results confirm the effectiveness and the robustness of the type-2 FLCs which outperform their type-1 counterparts, particularly when uncertainties are present in the system.
A Multi-Port Approach to Solve Distribution Networks with Meshes and PV Nodes
2007
A new methodology based on the backward/forward (b/f) technique for the load flow solution in distribution systems is here proposed. The methodology takes efficiently into account the fixed voltage nodes and uses a reduced bus impedance matrix. In this way, it is possible to attain, for the unknowns at the PV nodes, the same values that are attainable solving the network with the methods adopted for transmission systems. With the same methodology it is possible to take into account also the meshes. If the network contains only meshes, the relevant model is linear and it is the one including the compensation currents. The presence of PV nodes introduces non linearity in the model and an iter…
A Technical Approach to the Energy Blockchain in Microgrids
2018
The present paper considers some technical issues related to the “energy blockchain” paradigm applied to microgrids. In particular, what appears from the study is that the superposition of energy transactions in a microgrid creates a variation of the power losses in all the branches of the microgrid. Traditional power losses allocation in distribution systems takes into account only generators while, in this paper, a real-time attribution of power losses to each transaction involving one generator and one load node is done by defining some suitable indices. Besides, the presence of P–V nodes increases the level of reactive flows and provides a more complex technical perspective. For this re…