Search results for "Absorber"
showing 10 items of 53 documents
Wave Energy Assessment along Sicilian Coastline, Based on DEIM Point Absorber
2017
The use of renewable energy sources is one of the most relevant goals to be achieved in order to match the climate protection targets. As a case study, the paper shows the current electrical energy production by sources in the Sicilian context. Among the renewable energy sources, the paper investigates the wave energy potential along the Sicilian coasts, because of the favorable climate around the island. A point absorber is present in order to exploit this source. Two scenarios are presented, with two different levels of energy production.
Renewable energy sources to fulfill the global energy needs of a country: The case study of Malta in Mediterranean Sea
2016
The paper shows the advantages using different energy resources for the islands of Malta. Moreover, this work is focused on the analysis of the wave energy potential along Malta's coasts. This important resource can be exploited to produce electrical energy using an innovative Point Absorber based on a new generator prototype realized by University of Palermo. The use of renewable source will reduce greenhouses emissions and increase the energy independence of Malta. The procedures applied in the present article, as well as the main equations used, are the result of previous applications made in different technical fields that show a good replicability [1]-[7].
Near zero energy island with sea wave energy: The case study of Pantelleria in Mediterranean Sea
2016
In this paper the authors present a study of the transition of an energy generation system for a real MV/LV distribution system from one that is "fuel-based" to a "renewables-based" system in particular from sea wave energy, using the data acquired from an innovative generator prototype realized by University of Palermo. The study is carried out for a real islanded network located in the Island of Pantelleria (Mediterranean Sea). The procedures applied in the present article, as well as the main equations used, are the result of previous applications made in different technical fields that show a good replicability [1]-[7].
A mixed H<inf>2</inf>/H<inf>&#x221E;</inf>-based semiactive control for vibration mitigation in flexible structures
2009
In this paper, we address this problem through the design of a semiactive controller based on the mixed H 2 /H ∞ control theory. The vibrations caused by the seismic motions are mitigated by a semiactive damper installed in the bottom of the structure. It is meant by semiactive damper, a device that absorbs but cannot inject energy into the system. Sufficient conditions for the design of a desired control are given in terms of linear matrix inequalities (LMIs). A controller that guarantees asymptotic stability and a mixed H 2 /H ∞ performance is then developed. An algorithm is proposed to handle the semiactive nature of the actuator. The performance of the controller is experimentally evalu…
Greening island: Renewable energies mix to satisfy electrical needs of Pantelleria in Mediterranean sea
2016
In this article the authors analyze the renewable mix in order to satisfy the energy needs of a real island in the Mediterranean sea, Pantelleria, which represents an optimal starting point to increase the production of electrical energy from renewable sources in minor islands. In this text are exposed different alternative sources, such as solar, wind and wave energy. Moreover, it is exposed a project of an innovative conversion device proposed by Department of Energy of University of Palermo, compared to a different one proposed by Politecnico di Torino. The procedures applied in the present article, as well as the main equations used, are the result of previous applications made in diffe…
Mathematical modeling of vehicle frontal crash by a double spring-mass-damper model
2013
This paper presents development of a mathematical model to represent the real vehicle frontal crash scenario. The vehicle is modeled by a double spring-mass-damper system. The front mass m1 represents the chassi of the vehicle and rear mass m2 represents the passenger compartment. The physical parameters of the model (Stiffness and dampers) are estimated using Nonlinear least square method (Levenberg-Marquart algorithm) by curve fitting the response of a double spring-mass-damper system to the experimental displacement data from the real vehicle crash. The model is validated by comparing the results from the model with the experimental results from real crash tests available.
Shape optimization of high-energy absorbers
2018
In this paper, a new approach to simulate and to optimize the performances of a crash-box, in terms of energy absorption or acceleration peak, is presented. As soon as the maximum size of the crash-box (longitudinal and transversal dimensions) has been fixed, the new approach allows optimizing the shape of the transversal section and the thickness of the structure. Thanks to the proposed procedure, engineers can easily identify the best crash-box depending on the particular working conditions. The new method has been tested with different cases study by considering different objective functions. The obtained results show the procedure works well and also demonstrate that the optimal number …
Dissipative solitons for mode-locked lasers
2012
International audience; Dissipative solitons are localized formations of an electromagnetic field that are balanced through an energy exchange with the environment in presence of nonlinearity, dispersion and/or diffraction. Their growing use in the area of passively mode-locked lasers is remarkable: the concept of a dissipative soliton provides an excellent framework for understanding complex pulse dynamics and stimulates innovative cavity designs. Reciprocally, the field of mode-locked lasers serves as an ideal playground for testing the concept of dissipative solitons and revealing their unusual dynamics. This Review provides basic definitions of dissipative solitons, summarizes their imp…
Extended fractional-order Jeffreys model of viscoelastic hydraulic cylinder
2020
A novel modeling approach for viscoelastic hydraulic cylinders, with negligible inertial forces, is proposed, based on the extended fractional-order Jeffreys model. Analysis and physical reasoning for the parameter constraints and order of the fractional derivatives are provided. Comparison between the measured and computed frequency response functions and time domain transient response argues in favor of the proposed four-parameter fractional-order model.
Fabrication of Bismuth Absorber Arrays for NTD-Ge Hard X-ray Microcalorimeters
2020
The high-spectral-resolution detection of hard X-rays (E > 20 keV) is a challenging and nearly unexplored area in space astrophysics. Traditionally hard X-ray detectors present moderate spectral resolutions, although few tens of eV one could open new frontiers in the study of nuclear processes and high-temperature plasma dynamics in energetic processes. This can be achieved by using cryogenic microcalorimeters. Within a research activity aimed at developing arrays of neutron transmutation-doped germanium (NTD-Ge) microcalorimeters for the high-spectral-resolution detection (about 50 eV@60 keV) of hard X-rays (20 keV < E<100 keV), we developed an electroplating process to fabricate …