Search

The present case study reports a shear rheological characterization in the temperature domain of inks and pastes loaded with conductive High Reactivity Carbonaceous Material (HRCM) consisting mainly of few-layers graphene sheets. The combined effect of filler concentration and applied shear rate is investigated in terms of the shear viscosity response as a function of testing temperature. The non-Newtonian features of shear flow ramps at constant temperature are reported to depend on both the HRCM load and the testing temperature. Moreover, temperature ramps at a constant shear rate reveal a different viscosity–temperature dependence from what is observed in shear flow ramps while maintaining the same filler concentration. An apparent departure from the well-known Vogel–Fulcher–Tamman relationship as a function of the applied shear rate is also reported.

Thermal comfort and energy saving have become a priority for construction industry professionals. An important parameter of the comfort is the mean radiant temperature and its dependence on the building envelope. In the present research, a dynamic physical model has been studied in a climatic chamber, linked to the specific heat (C), density (r) and thermal conductivity (l). The heat capacity is usually quantifiable in small, homogeneous and uniform samples by the application of calorimetric methods. Consequently, the building energy consumption assessed through calorimetric methods, is often quite different from the energy consumption measured in situ. In this work an experimental model for the assessment of specific heat of real-size building components is proposed. Such a parameter was determined by measuring the heat flow through a building wall. The model has been validated by comparing the evaluated properties of known materials for different thermal gaps.

The fight against climate change has delineated new objectives, among which one of the most crucial is the replacement of high-energy-intensity materials in the construction sector with more sustainable and thermally efficient alternatives to reduce indirect emissions. Consequently, the thermal properties of materials assume fundamental importance. In this regard, the large-scale use of earth represents a promising option, not only due to its widespread availability but especially for its minimal embodied energy. However, to enhance its durability, it is necessary to stabilize the mixtures of raw materials. This study analyzes experimental systems based on earth stabilized with bio-based polymers to evaluate their thermal properties and how these vary depending on the selected mix-design. The experimental measurements showed thermal properties comparable to conventional materials. As expected, thermal conductivity increases when porosity decreases. The minimum value is equal to 0.216 W/m·K vs. a porosity of 43.5%, while the maximum is 0.507 W/m·K vs. a porosity of 33.2%. However, the data obtained for individual systems may vary depending on the topological characteristics, which were analyzed through a model for granular materials. The modeling suggests correlations between microstructures and thermal behaviour, which can be useful to develop tools for the mix-design procedure. [ABSTRACT FROM AUTHOR]

The paper presents a research carried out at the University of Cagliari during two academic years. The aim was to analyse the effect on students learning resulting from the introduction of a method based on questions and answers in a traditional large-classroom lecture. We investigated whether an interactive teaching approach, facilitated by an interactive software application based on mobile technologies, would lead to improved student engagement and learning outcomes in large-group of environmental engineering science lectures for undergraduate students. The goal was to assess the impact on learning outcomes, as well as the acceptance and appreciation of the students, of a lecture intermixed with questions and answers followed by analysis and discussion of the answers. In our experience we compared two different application of this methodology: with and without technology. The results obtained, in turn, were compared with those of a traditional lecture. Dispositivi mobili per aumentare l’attenzione e migliorare l’apprendimento Il contributo presenta una ricerca svolta all’Università di Cagliari nel corso di due anni accademici tesa ad analizzare le potenzialità di una modalità di lezione basata sull’uso frequente di “domande e risposte” gestite attraverso tecnologie. Abbiamo cercato di capire se un approccio didattico più interattivo, facilitato da un’applicazione software basata su tecnologie mobili, riesca a migliorare il coinvolgimento degli studenti e i risultati di apprendimento, in un contesto caratterizzato da un elevato numero di partecipanti. L’obiettivo era quello di verificare l’impatto sui risultati di apprendimento, oltre all’accettazione ed all’apprezzamento da parte degli studenti, di una didattica frontale intervallata da domande di verifica e dalla conseguente analisi e discussione delle risposte. Nell’esperienza sono state comparate due diverse modalità di applicazione di questa metodologia: con e senza le tecnologie e, i risultati ottenuti, sono a loro volta stati confrontati con quelli di una lezione tradizionale.

Among the actions to achieve the objectives set by the European Union in the "Fit for 55 Package" which sets a target of reducing net emissions of climatealtering gases by 55% by 2030, includes the EPBD Directive, with the aim of identifying and redevelop buildings with inadequate energy performance. The architectural assets subject to protection restrictions and the "complexes of immovable things that make up a characteristic aspect having an aesthetic and traditional value" remain outside the scope of application. In Italy, most of the historic buildings fall under this definition and among these the now abandoned prison structures, characterized by very high historical and architectural value but often left unused, spread practically throughout the national territory. Several local authorities introduced rules and prescriptions for the energy efficiency of the envelope into their regulations, but these remain applications limited to the local context, unable to give a universally valid procedure for the vast cultural heritage. The sporadic initiatives carried out up to now constitute a valid testimony on the possibility of overcoming the problems connected to the change in the use of the existing building. Starting from these successful cases, and not only at a national level, this research aims to provide a methodology for analyzing the existing and the today available "bacs", to support the design process for the reuse of these historic buildings. The proposed approach is based on environmental sustainability and tries to highlight those design choice parameters capable of solving the problems of integration with historical construction materials and ancient techniques constructive, overcoming the gap between the needs of the historical buildings and the available solutions. [ABSTRACT FROM AUTHOR]

The present case study reports a shear rheological characterization in the temperature domain of inks and pastes loaded with conductive High Reactivity Carbonaceous Material (HRCM) consisting mainly of few-layers graphene sheets. The combined effect of filler concentration and applied shear rate is investigated in terms of the shear viscosity response as a function of testing temperature. The non-Newtonian features of shear flow ramps at constant temperature are reported to depend on both the HRCM load and the testing temperature. Moreover, temperature ramps at a constant shear rate reveal a different viscosity–temperature dependence from what is observed in shear flow ramps while maintaining the same filler concentration. An apparent departure from the well-known Vogel–Fulcher–Tamman relationship as a function of the applied shear rate is also reported. [ABSTRACT FROM AUTHOR]

Thermal comfort and energy saving have become a priority for construction industry professionals. An important parameter of the comfort is the mean radiant temperature and its dependence on the building envelope. In the present research, a dynamic physical model has been studied in a climatic chamber, linked to the specific heat (C), density (λ) and thermal conductivity (λ). The heat capacity is usually quantifiable in small, homogeneous and uniform samples by the application of calorimetric methods. Consequently, the building energy consumption assessed through calorimetric methods, is often quite different from the energy consumption measured in situ. In this work an experimental model for the assessment of specific heat of real-size building components is proposed. Such a parameter was determined by measuring the heat flow through a building wall. The model has been validated by comparing the evaluated properties of known materials for different thermal gaps. [ABSTRACT FROM AUTHOR]

Copyright of Form@re is the property of Firenze University Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Italian energy policy has determined important keystones in building energy efficiency regulations and their application throughout the country. However, there is still much work to be done in order to make sustainable societies and territories, especially in historical contexts that have the greatest potentiality of energy saving. In detail, in the framework of conservation, restoration, refurbishment, and retrofit actions, the debate among scientists, administrators and skilled people is still open due to the many aspects yet to be considered and solved. In this paper, the state of the art of Italian residential building heritage has been reviewed, while energy retrofit issues and viable solutions have been investigated by collecting literature examples and experiences, focusing on common retrofit measures on historical buildings per thematic area. Finally, the advantages and disadvantages of each action have been discussed. Anyway, two main aspects have to be solved yet: the high Payback Times and the restriction about Renewable Energy Sources installation on this kind of buildings. [ABSTRACT FROM AUTHOR]

The application of retrofit actions to existing building stocks can improve the energy performance of the residential sector. In this context, particular attention should be given to historical buildings, which represent a large part of the Italian building stock. To improve the energy performance of them, adequate retrofit actions must be applied. Many studies and regulations have focused on identifying the best refurbishment measures. However, the selection of these measures is difficult due to restrictive regulations, which are dictated by the Ministry of Cultural Heritage and Activities, high retrofit costs, and variable climate zones. Thus, energy renovations in Italian buildings are not simple, and it is very difficult to find generic solutions that can be applied to buildings across the entire territory. In this paper, the authors investigated the most common retrofit solutions used in Italy, focusing in particular on the energy performance of historical building envelopes. First, energy performance analyses were conducted for two typical base cases in four different Italian cities using TRNSYS software, and some common retrofit measures were analysed. In some cases, the results showed Primary Energy saving of 44.6% (sample A) and 56.7% (sample B). Furthermore, these were used to identify different energy and economic impacts associated with the same refurbishment measures in different climatic contexts, highlighting the non-existence of a generic solution suitable for all regions or countries. [ABSTRACT FROM AUTHOR]

In Europe and worldwide several legislations are adopting comfort models that include the variability of occupants behaviour based on the external climate conditions. The latest adaptive comfort methods consider outdoor temperature not only as a steady variable but also as the representation of occupants past thermal history. The paper presented deals with a summer environmental monitoring carried out in a Sardinian earth building. These traditional houses are very often without AC systems and the control of summer conditions is based mainly on natural ventilation. By the use of adaptive comfort model, the different thermal performance between the upper and lower floor of the two storey building are investigated. Different models have been implemented, some included in current technical standards, some other still experimental. The results show the capability of the case-study to provide comfort conditions, but only in the lower floor. The upper floor that traditionally was used as a depository and now hosts the bedrooms shows overheating problems. The change of use, in this case, is the main cause of the bad performance, as highlighted by the microclimatic survey. [ABSTRACT FROM AUTHOR]