1,720,960 research outputs found
Il dottorato di Ricerca in Ingegneria Edile presso l’Università degli Studi di Cagliari
No full textThe paper describes the experience of the Three Year PhD course at the University of Cagliari. The paper describes in particular the topics discussed, the research paths, the ways of development of work, the experiences abroad; it identifies the critical situations both in terms of equipment available, both in terms of post-doctoral career opportunities
Intelligent glass and energy savings
No full textThe history of architecture has always been characterized by a continuous run up to the different degrees of translucency of the glass envelope, poised between transparency and opacity. But one of the main limitations of the glass was to never allow the variation of the degree of translucency unless you use shielding systems and jamming. Another big limitation of the glass has always been not to allow a high thermal and energy insulation. Today, thanks to chromogenic or photodynamic materials, ie materials able to change its characteristics of transparency to solar radiation as a function of the variation of physical parameters, the above problems can be solved. The paper, which summarizes a speech given at the Vitrum Energy 2009 Conference in Milan, describes the potential of new materials and researchs in progress at the University of Cagliari
Application of sustainable technologies in the future of historic buildings: electrochromic glass
No full textClimate change will continue to repeat the theme of the quantity and quality of
sources of energy production and the consequent needs of consumption saving. Countries, like
Italy, where there is an important historical and architectural heritage, must find systems and
techniques that achieve acceptable results with reasonable interventions combining environmental
aspects and economically feasible even when it is unthinkable to intervene heavily on the
composition of the building envelope. For several years, our research group is involved in energy
conservation with particular attention to the use of innovative materials, such as electrochromic
glazing, applied as a transparent building elements to the building envelope. Among the fields of
study there are simulations on the use of them in historic buildings. This area of research has
already affected the City Hall in Cagliari, a building of the late nineteenth century, the results of
which were presented at Heritage 2012. This research concerns the Royal Palace (Palace of the
Governor) of Cagliari, whose construction dates back to the thirteenth century, it is located in the
heart of the historic center in a very visible position. From residence of Pisan castellans, in the
course of time, it saw alternation the governors of the ruling houses. The building represents, as
well as an important architectural episode, a compendium of dominations that have occurred in
Sardinia.The restoration works of the 90th of the twentieth century, have given the current
configuration of the prospective fronts and final layout of the interior spaces, in which there are the
offices of the Province of Cagliari and those of the Prefecture. Inside there are valuable collections
of paintings, decorative paintings and furniture of great artistic and historical importance.The
simulation, starting from a 3D modelling of the building, through the use of a specific software,
compares the consumption in the current configuration with those that would be obtained with the
substitution of existing glass panels with EC glass. The simulation consideres the building in its
physical, construction and use characteristics. Then, maintaining substantially unchanged
appearance of the building, it will be reached as to quantify the internal comfort, the difference in
energy consumption and that one relating to the consumption of CO2
Architettura e sostenibilità nel Mediterraneo
No full textProgetto, costruzione e gestione dell'edificio, vitali alla architettura altamente sostenibile, si codificano da decenni anche con riguardo agli effetti sull'economia edilizia, avendo
contribuito il settore ad inquinamento ed esaurimento di
risorse non rinnovabili. Le ulteriori relazioni sperimentali tra materia e contorno vagliano su qualità ed innovazione prestazionale di materiali e costruito.
Fra molteplici materiali performanti, il versatile vetro circoscrive, in particolare, l'indagine del Dipartimento di Architettura di Cagliari. Per le prestazioni fornite ai fini
energetici di risparmio ed efficienza, i ricercatori proseguono l'indagine in ambito climatico locale, con l'edificazione di test room, a seguito dei promettenti esiti delle simulazioni sui
vetri elettrocromici. Di rilevante applicazione per effetti energetici e di comfort, gli elettrocromici consentono di ridurre l'apporto necessario alla climatizzazione estiva nelle
zone calde del Mediterraneo e, per traslucenza variabile,
forniscono codici lessicali di un'architettura finita e coerente
Electrochromic glass: behaviour and energy saving
No full textThe research group, from several years, dealing with Electrochromic Glass and their performance in the energy field. As already introduced in the presentation of the GPD 2011, the research, started with simulations using specific software, is at present, to being tested on real physical models. Two test rooms have been made perfectly identical as regards orientation, dimensions, materials, elements and construction system: in the first room EC glass were laid, in the second one Low-E glazing of equal size. In this phase, which began in January and will end in December 2012, at fixed times, the EC glazing go from OFF to ON condition. In both test rooms survey tools detect, at predetermined time, the most important indoor thermo physical parameters such as: temperature, air humidity and solar radiation. The data are recorded, processed and displayed in graphs showing the internal conditions related to outside parameters.
The objective of this step is to compare, in both rooms, the internal conditions of temperature and solar radiation to reach calculate consumption and energy costs required to achieve same indoor condition.
In the second phase, will study the thermal energy performance as a function of envelope variants. Most of all it‘ll be studied that one relating to the different relationship between glass and opaque surface
Electrochromic glazing in Contemporary Architecture: examples of use and opportunities for the future
No full textArchitecture and Construction are always reluctant to use innovative materials, althou gh characterized by promising performance levels, but with initial costs significantly higher than conventional
materials. This inertia is partly contrasted by the requirement for sustainable design that leads to organize construction processes ever more appropriate, through a careful analysis and selection of building materials and their performance related to system functions that the building must fulfill.
Currently the Architecture Department of Cagliari University is carring out a research that has as
principal objective the study on the possibility of ever more efficient use of materials, traditional -
used in innovative ways too - but also innovative and composites.
One of the first materials taken into account is the electrochromic glass, a special type of chromogenic
glass, a variable transparency glazing. EC windows are able to vary their characteristics of
transparency to solar radiation following application of a very small electric field. Are therefore
particularly suited to energy savings in summer for air conditioning of buildings, especially buildings
with large windows in Mediterranean climate. However, Ec materials are little known and little used.
This article therefore seeks to retrace the history of these materials, analyzing their characteristics,
their use in some case studies and methods of installation. Analyzed the state of the art, we will
explain briefly the ongoing research at the Cagliari University, which aims to test the actual
performance of electrochromic glazing, using them in a test room in a office building, and especially
with the comparison of data collected in a adjacent test room which has the same characteristics and
equipped with traditional glazing. A further aim of the next phase of experimentation is to evaluate the
durability of the materials and the possibility of glazing regulation, through the current possibilities
provided by home and building automation. In hot areas, such as in Mediterranean regions, where the
energy requirements of buildings is binding for most of the summer conditioning due to intense solar
inputs, electrochromic glazing represent, in the near future, a reasonable response in terms of Energy
savings. Currently they are among the more interesting components for achieving transparency,
sustainability and linguistic evolution of architectural envelope
Technologies of the future for the re-use of the past: the electrochromic glass
No full textThe changing needs related to ecosustainability issues stimulate all actors of the construction process to the organization of envelopes and more efficient building systems. This performance must be required not only in new buildings, but also in the conversion of existing heritage. This re-using sustainable vision, must go through a careful analysis and selection of building materials and systems related to them and their overall performance to the level of the building energy performance must be achieved. For several years, our research group is interested in innovative materials in the field of energy saving, with particular attention in transparent building components, regarding, specifically, the electrochromic glass (EC). The EC glazing elements are able to change, under user control, the color intensity of the glass itself which, going from light to dark, can shield 97% of visible light transmission and 99% solar incoming radiation. This cromatic change occurs through a chemical process of reversible oxidation-reduction that modifies, considerably and dynamically, the solar factor g (SHGC Solar Heat Gain Coefficient) and allows, at the same time, to maintain the visibility and the relationship outwards. The study concerns the city hall of Cagliari: a large Art Nouveau building (1897-1914), characterized, on all facades, by the presence of large glazing surfaces. The current system causes, due to the intense sunshine, under great un-comfort in the workplace. In the specific case study, it applies a computer simulation to compare the energetic performance of the current glazing system with those achieveble with the use of EC glass. Ultimate goal of research is the verification of the energy behavior and the level of indoor comfort reachable in traditional construction buildings with the application of innovative materials, combining the architectural value, functional recovery and environmental sustainability
Behaviour of the electrochromic glass in the Mediterranean area
No full textFor several years, our university research group is interested in innovative materials in the field of energy saving, with particular attention in transparent building components, regarding, specifically, the use of electrochromic glass (EC). The EC glazing elements are able to change, under user control, the colour intensity of the glass itself which, going from light to dark, can shield 97% of visible light transmission and 99% solar incoming radiation. This chromatic change occurs through a chemical process of reversible oxidation-reduction that modifies, considerably and dynamically, the solar factor g (SHGC Solar Heat Gain Coefficient) and allows, at the same time, to maintain the visibility and the relationship outwards. This technology, initially studied also from some European industries, is currently marketed only by an American company that has done all the tests required by U.S. regulations and it is now preparing to operate in Europe. The high sunshine that characterizes the climate of the Mediterranean regions makes this technology particularly interesting in relation to indoor comfort, energy savings and consequently the environmental respect, that the use of these glass could bring. Currently no specific studies, full scale, have been set for testing and evaluation of the EC in this very challenging. Our research group built, for this purpose, two identical test rooms for exposure, size (4x4x2.70 m) and composition of the envelope. In the first room we implemented low-emission glass and in the second one EC glass. Indoor comparative measurements have performed regarding the hydrothermal characteristics and at the same time all external meteorological parameters were recorded. In this paper we present in detail the results of this experiment and the conclusions for the tested period
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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