9 research outputs found
Characterization of the Magnetic Induction Field produced by Secondary Substations
The aim of this paper is to develop a methodology for measuring the magnetic field distribution around the prefabricated secondary substations in vibrated reinforced concrete, as well as the definition of a methodology to determining the maximum value of magnetic induction produced by the substations in correspondence to nominal current of the transformer. As proposed has been developed in conformity with laws and standards and can be applied to active and passive secondary substations. The experimental validation of the proposed methodology, carried out by a measurements campaign whose results are reported, confirms the validity and returns a versatile and simple tool for the verification of the quality targets required by current legislation
Caratterizzazione del campo di induzione magnetica prodotto da cabine secondarie
L’articolo presenta una metodologia per la caratterizzazione del campo di induzione magnetica nei pressi di cabine secondarie di tipo a box prefabbricato in cemento armato vibrato, che costituisce un valido strumento per la verifica del rispetto degli obiettivi di qualità imposti dalla legislazione vigente
Critical issues and future prospects of the secondary substation in smart grid context
This paper is focused on the new role of the secondary substation in the smart grids context. This innovative view has been proposed and developed in the framework of two Research Projects: NewCabELARC Project and Reipersei Project. The latter provides a concrete and comprehensive low cost solutions for the smart grid monitoring and control, allowing the real diffusion and integration of Distributed Generation and the full exploitation of Renewable Energy Sources. In this field, this paper shows how the secondary substation (SS) takes the role of smart transducer node where innovative devices can be located, collecting the measurement data coming from the field devices (power and energy meters and Interface Devices of Distributed Generators and Energy Storage Systems) and/or performing some local automation functions. They can also communicate with the grid (utility) for the remote control and management of the grid itself. Finally, SS safety issues are discussed and some feasible features that future smart substations are introduced
Chronostratigraphic sequence of Santuario della Madonna cave (Calabria, Southern Italy): AMS radiocarbon data from a new excavation area
From the 20th International Radiocarbon Conference held in Kona, Hawaii, USA, May 31-June 3, 2009.The Santuario della Madonna Cave, located near Praia a Mare (Cosenza), along the northwestern coast of Calabria (southern Italy), has an impressive stratigraphy, with occupation phases spanning from the late Paleolithic to the advanced phases of the Middle Bronze Age. Recently, a new excavation area has been opened in the cave from which short-lived vegetal remains were sampled and submitted for accelerator mass spectrometry (AMS) radiocarbon dating. The aim of this study was to define an accurate chronology of the different cultural aspects and to explore the potentialities resulting from application of advanced statistical tools for 14C data analysis in such a context.The Radiocarbon archives are made available by Radiocarbon and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform February 202
Experimental EMF characterization of a secondary substation
This paper presents the results of the experimental EMC characterization of a new medium/low voltage (MV/LV) secondary substation, which was developed in the framework of the research project "NEW CAB ELARC". It has two MV/LV transformers, with total rated power of 1000 kVA. To perform the experimental characterization, firstly an analysis was performed of the Italian and European standards recommendations. Different approaches were highlighted and the most appropriate procedures were identified for the measurement of the magnetic fields emissions, at power systems frequency (50 Hz) in steady-state conditions. A dedicated test lab was set up for the secondary substation characterization. The measurement results showed that, thanks to the chosen layout, the emissions of the substation under test are lower than those of typical substations of the same power
Li-ion Battery Modeling and State of Charge Estimation Method Including the Hysteresis Effect
In this paper, a new approach to modeling the hysteresis phenomenon of the open circuit voltage (OCV) of lithium-ion batteries and estimating the battery state of charge (SoC) is presented. A characterization procedure is proposed to identify the battery model parameters, in particular, those related to the hysteresis phenomenon and the transition between charging and discharging conditions. A linearization method is used to obtain a suitable trade-off between the model accuracy and a low computational cost, in order to allow the implementation of SoC estimation on common hardware platforms. The proposed characterization procedure and the model effectiveness for SoC estimation are experimentally verified using a real grid-connected storage system. A mixed algorithm is adopted for SoC estimation, which takes into account both the traditional Coulomb counting method and the developed model. The experimental comparison with the traditional approach and the obtained results show the feasibility of the proposed approach for accurate SoC estimation, even in the presence of low-accuracy measurement transducers
The genomic history and global expansion of domestic donkeys
Donkeys transformed human history as essential beasts of burden for long-distance movement, especially across semi-arid and upland environments. They remain insufficiently studied despite globally expanding and providing key support to low- to middle-income communities. To elucidate their domestication history, we constructed a comprehensive genome panel of 207 modern and 31 ancient donkeys, as well as 15 wild equids. We found a strong phylogeographic structure in modern donkeys that supports a single domestication in Africa ~5000 BCE, followed by further expansions in this continent and Eurasia and ultimately returning to Africa. We uncover a previously unknown genetic lineage in the Levant ~200 BCE, which contributed increasing ancestry toward Asia. Donkey management involved inbreeding and the production of giant bloodlines at a time when mules were essential to the Roman economy and military.info:eu-repo/semantics/publishedVersio
Thermal behavior study of pristine and modified halloysite nanotubes
Pristine halloysite nanotubes (HNTs) were
studied by thermogravimetry (TG) up to 800 °C. Etching
of alumina from inside the tube (causing a significant increase
in tube lumen) was realized by treating the material
with an acidic H2SO4 solution at 50 °C. Both materials
were characterized by TG-FTIR techniques and their
thermal behaviors were compared with that of kaolinite.
The coupling of TG with FTIR enables to detect the gases
evolved during the TG experiments, thus confirming that
only pristine HNTs undergo dehydration with the loss of
interlayer water molecules at around 245 °C, while dehydroxylation
occurs in all these materials in close temperature
ranges around 500 °C. TG runs at five different
heating rates (2, 5, 10, 15 and 20 °C min-1), was carried
out in the same experimental conditions used for the
thermal analysis study with the aim to investigate dehydration
and dehydroxylation kinetics using some isoconversional
methods recommended by the ICTAC kinetic
committee, and thermogravimetric data under a modulated
rising temperature program. Finally, the results of the kinetic
analysis were discussed and explained in terms of the
strengths of the hydrogen bonds broken during these
processes