1,720,963 research outputs found
Misure spettrofotometriche per la caratterizzazione delle proprietà ottiche di vetri con pellicole a controllo solare.
No full textTra i materiali innovativi che si sono diffusi negli ultimi anni vi sono le cosiddette pellicole a controllo solare, da applicare a lastre vetrate, con marcate proprietà riflettenti. Il lavoro, effettuato presso il Laboratorio di Termotecnica dell’Università di Perugia, presenta una vasta campagna sperimentale per la determinazione delle proprietà ottiche (trasmissione e riflessione spettrali) di vetri semplici e doppi di vari spessori, con applicazione di pellicole a
controllo solare di diverso tipo. A partire dai dati sperimentali, si sono calcolati i parametri che caratterizzano le prestazioni illuminotecniche ed energetiche del materiale, come il fattore te, sia per l’incidenza normale che per alcuni angoli di incidenza significativi. I dati ottenuti possono essere impiegati in codici di calcolo per la valutazione delle prestazioni energetiche ed illuminotecniche degli edifici
Solar energy technologies in sustainable energy action plans of italian big cities
Full text linkCities, accounting for more than 3/4 of global final energy consumption, are equipping themselves with governance tools to improve energy efficiency. In Europe, urban energy policy has adopted, only recently and voluntarily, the Sustainable Energy Action Plans (SEAP), following the European Strategy 20-20-20. Italy, country most sensitive among European ones, accounts for 53% of SEAPs signatories. In order to evaluate how urban energy system in Italy can match sustainability European goals, it is necessary to analyse the technological options promoted by the energy policies for the urban environment. The paper presents the state-of-art of Urban Energy Planning in Italy, focusing on the implementation of Solar Energy technologies, and their role in new urban energy strategy instruments, i.e. SEAP, to promote renewables deployment. Carbon emission avoidance interventions planned by Italian big cities were analysed, highlighting the chosen Solar Energy technology. The aim of this paper is to discuss and evaluate the differences of solar energy harvesting in Italian urban scenarios, taking into account geographical and morphological constraints, and to compare the forecasts for 2020 and 2030scenarios, in accordance with European and National laws in force
Proposta di un pannello a concentrazione per la produzione di idrogeno mediante il ciclo ZnO-Zn
No full textNegli ultimi anni si è assistito ad un crescente interesse da parte della comunità scientifica internazionale verso lo studio e l’individuazione di fonti di energia rinnovabili. Le fonti di energia tradizionali, derivate da combustibili fossili, oltre a contribuire in maniera determinante al problema ambientale sono infatti destinate ad esaurirsi entro i prossimi decenni. È in questo contesto che l’idrogeno sta emergendo come possibilità alternativa, uscendo dalle ipotesi utopistiche ed assumendo un ruolo cruciale nella ricerca attuale. L’ostacolo principale alla diffusione dell’idrogeno come combustibile è la disponibilità di tale elemento in natura solo in forma combinata; occorre quindi utilizzare energia per produrlo.
In questa memoria, viene proposto ed analizzato da un punto di vista energetico un dispositivo innovativo per la produzione di idrogeno da energia solare mediante cicli termochimici. L’energia necessaria al compimento delle reazioni è fornita dal Sole. Il ciclo termochimico realizzato all’interno del dispositivo è quello basato sugli ossidi di zinco, individuato quale ciclo più conveniente sulla base di fattori termodinamici e cinetici. Tale ciclo prevede la dissociazione di ZnO in zinco ed ossigeno, ad una temperatura di 2000°C
Innovative Use of Hydrogen in Energy Retrofitting of Listed Buildings
Full text linkExisting buildings represent the major challenge in energy efficiency strategies applied to the building stock. Moreover, architectural and landscaping constraints related to listed buildings are further limitations to possible interventions. When listed buildings are used as museum, achieving the same effectiveness level of typical energy efficiency measures is very difficult and, if possible, very expensive. In order to couple preservation of cultural heritage and CO2 emission reduction, the approach would move to energy supply rather than modifications in building envelope or installation of new HVAC components. So, this study focuses on the opportunity to green NG supply of existing heating systems by means of Power to Gas option at district level. Thus, the recent advancements in Hydrogen enriched Natural Gas produced by RES electricity excess offer a zero-impact strategy to decarbonize the listed buildings using existing energy infrastructures. At the same time, the absence of changes in building features and the introduction of a renewable share in the supply address the sustainability issues of cultural heritage. In conclusion, a first original attempt was made towards the future crucial task of museum's deep energy refurbishment
Energy Contribution of OFMSW (Organic Fraction of Municipal Solid Waste) to Energy-Environmental Sustainability in Urban Areas at Small Scale
Full text linkUrban waste management is one of the most challenging issues in energy planning of medium and large cities. In addition to the traditional landfill method, many studies are investigating energy harvesting from waste, not as a panacea but as a foreseeable solution. Thermo-chemical conversion to biogas, or even bio-methane under certain conditions, could be an option to address this challenge. This study focuses on municipal solid waste conversion to biogas as a local energy supply for the cities. Three urban models and their subdivision into urban areas were identified along with a typical Organic Fraction of Municipal Solid Waste (OFMSW) matrix for each urban area. Then, an energy analysis was carried out to provide an optimization map for an informed choice by urban policy-makers and stakeholders. The results highlighted how the urban context and its use could affect the opportunity to produce energy from waste or to convert it in fuel. So, in this case, sustainability means waste turning from a problem to a renewable resource
Selecting eco-friendly thermal systems for the "Vittoriale Degli Italiani" historic museum building
Full text linkThermal systems installed in museums should guarantee the maintenance of the optimal hygrothermal parameters ranges for the conservation of their collection materials. Considering the preservation of historic buildings, according to their historical and landscaping constraints, not all the thermal system typologies could be installed in these buildings' typologies. Therefore, the main aim of this paper is to present some indications for the choice of the best thermal system solutions for a considered historic museum building, called Vittoriale degli Italiani, in the north of Italy, taking into account their installation feasibility and their related environmental impacts. The methodology includes a monitoring of the current hygrothermal parameters as well as the assessment of design heat and cooling loads related to the maintenance of the optimal hygrothermal parameters ranges for the conservation of collection materials. In addition, a Life Cycle Assessment (LCA) of each selected system typology is considered for highlighting the most eco-friendly solution among the suitable ones. The obtained results highlights the feasible thermal system solutions able to maintain the hygrothermal parameters between the optimal ranges with a lower environmental impact in the Vittoriale degli Italiani historic museum building
Methodological proposal for optimal location of emergency operation centers through multi-criteria approach
Full text linkTerritorial vulnerability and risk analysis play a fundamental role in urban planning and emergency management. Requirements analysis of such aspects are possible to define more and more effective risk mitigation strategies providing efficient response plans to events. Many mitigation strategies as well as many response plans have in common the purpose of minimizing response time in order to decrease the level of vulnerability of the concerning area. The response time to a perturbing event is in fact an essential parameter to define the hazard of the considered site and literature is unanimous in considering it. In this context, the article proposes a methodology for the optimization of the location on the territory of emergency operation centers (EOCs), reducing response times and mitigating in this way the vulnerability of the area. The proposed methodology is based on a multi-criteria decision making (MCDM) hybrid type AHP (Analytic Hierarchy Process)-Electre. This method has been applied in the territory of Bressanone and Vipiteno (Bolzano-Italy), simulating the need to build a new barrack of Fire Department. A campaign of interviews with operators and industry experts and the collection of spatial data from the portals of the concerned authorities has been carried out in order to get the number of necessary data for the implementation of the proposed methodology
New millennium construction sites: an integrated methodology for the sustainability assessment
Full text linkAccording to the Global Status report for Buildings and Construction, the building and construction sector accounts for 36% of global energy consumption and 39% of energy-related carbon dioxide (CO2) emissions. Specifically, the construction site represents one of the most significant sources of environmental impact, making it a pivotal element in achieving sustainability within the construction industry. The construction process and maintenance activities on buildings are, therefore, critical phases in which the construction industry is tasked with finding a balance between economic development, social well-being, and environmental protection to ensure a sustainable future for both current and future generations. To promote a construction model focused on environmental, economic, and social sustainability, this paper introduces a Performance Protocol. This protocol serves as an operational tool that allows both the construction company and the contracting authority to manage these aspects throughout the entire construction process. Digital technologies such as BIM and Digital Twin can take advantage of such model to integrate and develop sustainability analysis and simulation during the entire life cycle of a building. The use of digital tools is one of the challenges for the future of the built environment that needs to address not only the issues related to costs and management but also considering the social and environmental aspects of sustainable development
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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