1,720,984 research outputs found
Integrated envelope design process: innovative materials and technologies for a sustainable refurbishment of the existing building stock
Full text linkThe research project seeks to investigate and promote a new energy efficient architectural strategy for the refurbishment of existing
building stock, by proposing innovative and sustainable envelope solutions based on process by-products concept and bio-mimetic
approach. The project aims optimizing the exploitation of innovative sustainable materials and technologies to develop a continuous
and adaptive façade system that could guarantee high performance, by using a new class of materials (AAM), obtained through the
alkali-activation process of ceramic industrial waste
Progettazione integrata dell’involucro edilizio: materiali e tecnologie innovative per il recupero sostenibile del patrimonio esistente
No full textIl progetto di ricerca intende indagare e promuovere una nuova strategia sostenibile ed efficiente per la riqualificazione architettonica ed energetica del patrimonio edilizio recente, proponendo soluzioni di involucro innovative e sostenibili, basate su un approccio biomimetico e sul principio di riciclo di materiali. Lo studio è volto all’esplorazione e all’ottimizzazione di materiali e tecnologie innovative per lo sviluppo di un sistema di facciata continuo e adattivo, in grado di garantire elevate prestazioni, mediante l’uso di una nuova classe di materiali (AAM – Alkali Activated Materials), ottenuti dal processo di attivazione alcalina degli scarti industriali di lavorazione ceramica
Towards nZEBs: innovative materials and technologies for new sustainable envelope
No full textRenovation of existing recent buildings indicates a key factor for sustainability, contributing both to reduce the consumption of resources and raw materials, which often have reached only half of their life cycle, and to extend the buildings’ long-term functionality. Furthermore, these interventions would offer an alternative to the high costs for demolition and reconstruction, according to wants and needs of the different customers in the construction sector.
The research seeks to investigate a new energy efficient architectural strategy for the refurbishment of the existing building stock (i.e. housing, schools, offices) towards nZEBs, by proposing new envelope solutions based on process by-products concept and bio-mimetic approach. The project aims at optimizing the exploitation of innovative sustainable materials and technologies to develop a continuous and adaptive façade system that could guarantee high performance, by using a new class of materials from renewable sources (AAM - Alkali Activated Material). This AAM is obtained through the alkali-activation process of ceramic industrial waste, combined with an activator solution containing a glass siliceous material, dried at room temperature, with low production of CO2 emissions. The final product presents excellent mechanical and thermal properties.
The project identifies a sustainable strategy for managing the design and production process of “active” dry assembled envelope components, supported by geometrical survey, connected to parametric programming software for modelling the surfaces adaptable to the existing building morphology. These computerized CAD-CAM tools are connected to CNC machines for the mass customized industrialized production of different envelope solutions, according to the principles of sustainability, meant as modularity, speed of setup, reversibility and recycling of materials with low environmental impact.
Hence, the research presents a new integrated approach to support operators during the refurbishment interventions, through the use of innovative continuous envelope solutions that could guarantee high performance and good quality of final products
A climate risk hedge? Investigating the exposure of green and non-green corporate bonds to climate risk
Full text linkWe perform an in-depth analysis of climate risk in the corporate bond market, focusing on the green-bond issuers of the three largest European Union economies by GDP: Germany, France, and Italy. We do so by evaluating the impact, on the spreads of their green and non-green bonds, of a number of potential physical risk drivers, selected in line with the ECB climate stress tests and the extant literature, and through the fitting of ARIMAX models. Additionally, we include the log-returns of EU carbon allowances as a potential proxy of transition risk. We find that green and non-green bonds of the same issuer can differ in their exposure to the physical risk variables. Depending on the issuer, green bonds can be equally or less exposed than their non-green counterparts. Additionally, multiple firms in the renewable energy sector have green bonds which provide protection against physical risk. EU carbon allowances are not found to have a consistently significant impact on bond spreads. In line with these findings, we propose an extension of an intensity-based (reduced-form) credit risk model and assess its ability to describe and fit the bond data
Dynamic effects of wind loads on a gravity damper
No full textThe gravity damper is safety device used for the air treatment that prevent overpressure inside the unit through the opening. It is a normally closed valve under the effect of the gravity force, which, under the action of the incident air flow, allows to manage any excess mass. Clearly, although the device is rather simple and therefore reliable, the operating conditions may prove burdensome, especially if the gravity dampers are applied to installations of energy transformation, such as the gas turbines; this is mainly due to the need to develop large masses of air at speeds rather incurred. This article describes an experiment carried out on a gravity damper designed to be installed in a gas turbine. The characterization has been performed in numerical (CFD-FEM), considering both the mode shapes and the natural frequencies of the device in working condition as well as any phenomenon of detachment of the fluid that can trigger vortex shedding and subsequently validated in the wind tunnel facilities of the University of Perugia. In particular, what is wanted to be highlighted is the fact that, after a preliminary analysis, it has been clearly evident that, under the operating conditions, the structure would be affected by phenomena of vortex shedding. The shedding frequency is next to some natural frequencies of the structure, with obvious repercussions on the integrity of the structure. An experimental vibration analysis performed in the wind tunnel at flow regime has in fact allowed to identify the phenomenon of lock-in
Strumenti e metodi per la progettazione parametrica di un procedimento costruttivo innovativo
No full textObiettivo dello studio è quello di analizzare le potenzialità di un procedimento costruttivo innovativo e di verificarne l’applicabilità attraverso lo sviluppo di un progetto architettonico nel rispetto dei principi della sostenibilità di prodotto e di processo, della bioclimatica, dell’economicità ed ottimizzazione dei costi di costruzione e dell’assemblaggio a secco. In particolare la ricerca si è focalizzata sullo sviluppo di una metodologia di analisi di tipo computazionale mediante l’utilizzo di software parametrico-variazionali, con lo scopo di fornire un ausilio al progettista nell’elaborazione di soluzioni ottimizzate secondo i criteri e i requisiti prefissati dal procedimento costruttivo
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
Numerical and experimental investigation of a monotube hydraulic shock absorber
No full textThis work is devoted to the dynamics of a hydraulic monotube shock absorber, whose design resembles racecar vehicles dampers, prototyped at the University of Perugia for scientific purposes. A physical approach is adopted for numerical modeling of the global operation of the device, and the model is validated against a comprehensive test bench experimental campaign, conducted at velocities and frequencies typical of racecar vehicles. The main peculiarity of the prototype is that it is built in Plexiglas, and therefore, it has transparent walls allowing experimental tests with optical acquisition through high-speed camera. This provides a completely novel perspective, because it is possible to observe the evolution of the internal behavior, through the optical access, jointly with standard experimental test approaches. These experimental techniques are especially fit for the analysis of the cavitation phenomenon: the influence of the main boundary conditions (compensation pressure, fluid temperature) on the onset and the evolution of cavitation is investigated. Further, the influence of cavitation, according to its evolution, on the performances of the device is investigated. In particular, it is further shown that the optical acquisition is fundamental to have insight on the incipient and evolving phases of cavitation, which cannot be observed through the common techniques found in the literatur
The Knocking Noise on Twin Tube Shock Absorbers: Individuation and Analysis of the Phenomenon
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