Search results for " rene."
showing 10 items of 258 documents
The resilience of Finnish farms: Exploring the interplay between agency and structure
2020
Resilience implies, in its essence, the capacity of a system to tolerate disturbances while retaining its essential functions. In the context of agriculture, resilience thinking calls for considering the ability of farms to thrive in turbulent times along with the ability of the ecological system – in which the agricultural production is embedded – to retain its function and integrity. Resilience is a relevant conceptual tool to analyse the contradictory management demands that farms are facing within the current neoliberal market regime: being economically viable and environmentally sustainable. In this study, the resilience of farms was operationalised through farmers' perceptions concern…
MUTAMENTI E PERMANENZE DELLA PALERMO ANTICA MUTATIONS AND PERMANENCES IN ANCIENT PALERMO
2017
La Palermo Antica si identifica con il Centro Storico, la cui complessità è il frutto dell’incontro di culture succedutesi nei secoli e che ha dato alla città la sua attuale facies. Questi luoghi sono oggi un microcosmo complesso dove i modelli culturali dei nuovi abitanti si relazionano al preesistente generando nuove espressioni dell’intervento antropico. L’analisi è volta ai nuovi scenari urbani, alle impronte, ai segni e ai mutamenti generati da un processo insediativo che vede coinvolti i nuovi residenti e le loro risorse, in un ambito che ha tutte le potenzialità per restituire Palermo al suo ruolo di capitale nell’ottica dell’integrazione, dell’accoglienza, della riqualificazione e v…
Energy balance and life cycle assessment of small size residential solar heating and cooling systems equipped with adsorption chillers
2017
Abstract Solar heating and cooling systems for space heating and cooling are experiencing a growing trend and interest. However, the actual energy and environmental performance of small/medium size installations is not clearly foreseeable. In this paper, an analysis of such systems using adsorption chillers in different European climates is presented. Solar systems have been simulated in TRNSYS and compared to a conventional system employing a vapour compression unit. The results have been used for a Life Cycle Assessment (LCA) study, determining the potential impact during the whole life of the system, from raw materials supply to its end-of-life. The LCA has been carried out by using the …
Convergence of Markov Chains
2020
We consider a Markov chain X with invariant distribution π and investigate conditions under which the distribution of X n converges to π as n→∞. Essentially it is necessary and sufficient that the state space of the chain cannot be decomposed into subspaces that the chain does not leave, or that are visited by the chain periodically; e.g., only for odd n or only for even n.
Day-ahead forecasting for photovoltaic power using artificial neural networks ensembles
2016
Solar photovoltaic plants power output forecasting using machine learning techniques can be of a great advantage to energy producers when they are implemented with day-ahead energy market data. In this work a model was developed using a supervised learning algorithm of multilayer perceptron feedforward artificial neural network to predict the next twenty-four hours (day-ahead) power of a solar facility using fetched weather forecast of the following day. Each set of tested network configuration was trained by the historical power output of the plant as a target. For each configuration, one hundred networks ensembles was averaged to give the ability to generalize a better forecast. The train…
A Battery-Free Smart Sensor Powered with RF Energy
2018
The development of Internet of Things (IoT) infrastructure and applications is stimulating advanced and innovative ideas and solutions, some of which are pushing the limits of state-of-the-art technology. The increasing demand for Wireless Sensor Network (WSN) that must be capable of collecting and sharing data wirelessly while often positioned in places hard to reach and service, motivates engineers to look for innovative energy harvesting and wireless power transfer solutions to implement battery-free sensor nodes. Due to the pervasiveness of RF (Radio Frequency) energy, RF harvesting that can reach out-of-sight places could be a key technology to wirelessly power IoT sensor devices, whic…
Simulation of photovoltaic installation connected to the grid with storage system
2017
Abstract In the present paper, a new approach for the management of energy resources in a research laboratory is proposed and evaluated. A simulation study for the photovoltaic (PV) installation was conducted under the Tunisian-Italian cooperation project DE.DU.ENER.T, using renewable energy and economic criteria. The aim of the study is to improve the energy efficiency in order to minimize the electricity cost consumed in the laboratory. A Hybrid Renewable Energy System consisting of a photovoltaic field of 12KWc was installed to reduce the exorbitant bills, due to intensive energy equipment such as drying ovens and workstations, using sustainable, green and clean sources. In addition, a s…
A review of thermochemical energy storage systems for power grid support
2020
Power systems in the future are expected to be characterized by an increasing penetration of renewable energy sources systems. To achieve the ambitious goals of the “clean energy transition”, energy storage is a key factor, needed in power system design and operation as well as power-to-heat, allowing more flexibility linking the power networks and the heating/cooling demands. Thermochemical systems coupled to power-to-heat are receiving an increasing attention due to their better performance in comparison with sensible and latent heat storage technologies, in particular, in terms of storage time dynamics and energy density. In this work, a comprehensive review of the state of art of theore…
Unmanned Aerial Vehicle-Based Non Destructive Diagnostics
2018
The paper proposes a cloud platform for analyzing the radiometric infrared videos uploaded by drones which patrol large photovoltaic plants. Thanks to artificial vision algorithms, it does not require any human support to select and associate the framed PV modules to the corresponding ones in the topology of the photovoltaic plant. The algorithm implements an innovative diagnostic protocol, which evaluates the thermal state of the photovoltaic module, whichever the environmental conditions are. The data automatically computed and collected in a multimedia database provide the O&M technicians with significant information to monitor the ageing of each module of the photovoltaic plant. The pro…
Innovation for the Italian agricultural and food industry sector
2020
The food industry is one of the largest energy consumers in the world, with 95 EJ/year. In this context, in Europe the amount of energy needed to cultivate, process, package and bring food to the homes of citizens reached 285 Mtoe in 2015, of which 14 Mtoe due to the Italian agricultural and food system. With the aim of favoring a drastic reduction in energy consumption, the European Commission, and the main international agencies, ie: FAO, OECD, UN over the last decade have aligned on the need to develop policies to support energy efficiency, renewable energies and sustainable technologies in order to minimize the use of fossil fuels and to reduce the final energy consumption, especially i…