Search results for "Figuration"
showing 10 items of 615 documents
Are compliance constants ill-defined descriptors for weak interactions?
2013
Just as the potential energy can be written as a quadratic form in internal coordinates, so it can also be expanded in terms of generalized forces. The resulting coefficients are termed compliance constants. In this article, the suitability of compliance constants as non-covalent bond strength descriptors is studied (a) for a series of weakly bound hydrogen halide–rare gas complexes applying a configuration interaction theory, (b) for a double stranded DNA 4-mer using approximate density functional methods and finally (c) for a double stranded DNA 20-mer using empirical force fields. Our results challenge earlier studies, which concluded the inappropriateness of compliance constants as soft…
Electrical Safety of Resonant Grounding
2019
The resonant grounding is one of the possible methods of system neutral grounding for the medium-voltage distribution. IEEE standards do define this grounding configuration, but important advantages and drawbacks of the resonant grounding might not be fully known, due to its rather uncommon application in North America. On the other hand, resonant grounding in Europe is imposed by the increased requirements for power quality, especially for medium-voltage industrial users, and imposed to electric utilities by Regulatory Authorities, with the purpose to protect the interests of users and consumers. Level of the continuity of the service, magnitude and phase of ground-fault currents, magnitud…
Fast solution of radial distribution networks with automated compensation and reconfiguration
2000
Abstract Optimal operation of radial distribution networks with automated compensation and reconfiguration requires the solution of a combinatorial optimisation problem, since the variables are the on/off status of capacitor banks and the open/close status of tie-switches. The solution approaches recently proposed use iterative algorithms such as genetic algorithms, simulated annealing and tabu search, for which the network needs to be solved in different configurations and at different compensation levels. The aim of this evaluation is that of attributing a quality index to each solution so that all the solutions can be suitably ordered. In an automated network, any configuration can be ob…
Montatura polifunzionale per occhiali
2018
La presente invenzione ha come oggetto una montatura polifunzionale per occhiali, del tipo che consente la rapida sostituzione delle parti che la compongono. Tutti i componenti sono realizzabili con stampa ad iniezione, processo che ne rende i costi di produzione estremamente contenuti. L'assemblaggio avviene senza uso di viti o perni metallici. The present invention has as its object a multifunctional frame for eyeglasses, of the type which allows the rapid replacement of the parts that compose it. All components can be produced with injection molding, a process that makes production costs extremely low. Assembly is carried out without using screws or metal pins.
La Piazza del Garraffello a Palermo tra iconografia storica e attualità
2018
The proposed contribution is focused on the graphic analysis of an eighteenth-century perspective view portraying one of the most ancient squares of the City of Palermo (piazza Garraffello). It is an engraving print made by F. Cichè in 1711 on commission of the Guild of Silversmiths: the square is completely described with the fountain (still existing) in the foreground, and with the corporate lodges of foreign nations in the background (these two buildings nowadays have disappeared). In the picture is also visible a temporary triumphal arch with canopy erected by the same guild who had commissioned the view: this is the object of main perspectival interest. The study of the perspective use…
The project for the “Galleria Oretea” by Giuseppe Damiani Almeyda and other unbuilt “passages” in Palermo
2022
The contribution aims to conjecturally reconstruct and analyze the unrealized project by Giuseppe Damiani Almeyda regarding the “Galleria Oretea” for Palermo. It is an urban project of considerable size and impact, which should have provided the city of Palermo, in the old town, with a gallery in the style of the Parisian “passages”, inspired by the contemporary creations of Milan and Naples. Thanks to the recent cataloging and publication of the entire corpus of drawings in the Damiani Archive, a reinterpretation of the project was carried out through a three-dimensional recomposition of the immersed in the places where it was originally conceived. Two other projects were developed for the…
PV/T systems: Effect of both storage features and load configuration
2019
PV/T panels are innovative systems increasingly used in the building sector. Their energy production and overall efficiency depend on several factors related to the shares of electrical and thermal loads and to the working temperature of the operating fluid. Therefore, an optimal configuration should be found. In this work, a parametric analysis was performed to provide a contribute on this issue. The conclusive indications can be exploited by designers and researchers, to maximize the efficiency of the systems in relation to configurations and to both electrical and thermal loads. To this purpose a simulation model was designed and implemented in a spreadsheet, using Visual BasicTM functio…
Feasible Domain-Driven Genetic Operators for Distribution Systems Optimal Reconfiguration
2010
In this paper, the problem of minimum losses reconfiguration in weakly meshed medium voltage (MV) distribution systems is dealt with. The presence of meshes can either be a cause of the presence of particular loads, favoured customer (FC) nodes, requiring a double supply path or of distributed generation (DG) nodes, that cannot work in islanded mode. The problem has been brought back to the more general problem of radial networks reconfiguration with the major aim of minimising power losses subject to constraints on voltage drops at load nodes and current in branches as well as on the partition of power generated among supply nodes in the network. The problem is non-linear and combinatorial…
Multiobjective Optimal Reconfiguration of MV Networks with Different Earthing Systems
2010
The paper deals with the traditional problem of multiobjective optimal reconfiguration applied to power distribution systems considering the safety issue in the formulation. The applications are devoted to the solution of the posed problem in networks in which coexist energy sources with unearthed neutral point and resonant earthed neutral point. After a brief review of the most recent papers on optimal reconfiguration, the paper outlines the safety problem and provides a solution to the multiobjective problem using the Non dominated Sorting Genetic Algorithm II aiming at: minimal power losses operation, safety check at distribution substations and load balancing among the HV/MV transformer…
Apparato di commutazione
2012
La presente invenzione si riferisce ad un apparato di commutazione per il controllo e l'impostazione della configurazione circuitale dei pannelli di un modulo fotovoltaico.