57 research outputs found

    Development of a Solar-reflective Ceramic Tile Ready for Industrialization

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    Solar-reflective surfaces represent an effective countermeasure to UHI. The market of "cool" materials is dominated by polymeric solutions which, under UV exposure, are damaged. On the other hand, an increasing attention was paid recently to ceramic-based solar-reflective surfaces, characterized by very long lifespan. A ceramic tile is typically made by a three layers structure: substrate-engobe-glaze. This structure has been exploited to develop a cool ceramic tile that can be produced in the same production facilities of common products to create a whole tile by merging technological results and industrial production needs, to achieve a compromise between performance and costs

    Review on the Influence of Biological Deterioration on the Surface Properties of Building Materials: Organisms, Materials, and Methods

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    A strong attention is recently paid to surface properties of building materials as these allows controlling solar gains of the building envelope and overheating of buildings and urban areas. In this regard, deterioration phenomena due to biological aggression can quickly damage solar-reflecting roof surfaces and thus increase sharply solar gains, discomfort, air-conditioning costs and waterproofing degradation. The same deterioration problem has deleterious effect on cultural heritage, ruining its huge historic and artistic value. This work is aimed at providing an overview on the different organisms that affect the surface of most used building materials, to support the design of new building materials with long-lasting surface properties and to find a way to preserve cultural heritage. Artificial ageing is the long-term aim of this investigation, in which what in nature happens after months or years is compressed in a very short time by forcing the growth of microorganisms through a strict control on the different conditioning factors. Both natural and artificial ageing are eventually outlined in the last part of this work to provide a comprehensive idea of what is necessary to study in a complete way biological ageing protocols on building materials. Several characterization techniques are also introduced to analyse the influence of microorganisms on the surface of different building materials

    Differential diagnosis of neurodegenerative dementias with the explainable MRI based machine learning algorithm MUQUBIA

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    Biomarker-based differential diagnosis of the most common forms of dementia is becoming increasingly important. Machine learning (ML) may be able to address this challenge. The aim of this study was to develop and interpret a ML algorithm capable of differentiating Alzheimer's dementia, frontotemporal dementia, dementia with Lewy bodies and cognitively normal control subjects based on sociodemographic, clinical, and magnetic resonance imaging (MRI) variables. 506 subjects from 5 databases were included. MRI images were processed with FreeSurfer, LPA, and TRACULA to obtain brain volumes and thicknesses, white matter lesions and diffusion metrics. MRI metrics were used in conjunction with clinical and demographic data to perform differential diagnosis based on a Support Vector Machine model called MUQUBIA (Multimodal Quantification of Brain whIte matter biomArkers). Age, gender, Clinical Dementia Rating (CDR) Dementia Staging Instrument, and 19 imaging features formed the best set of discriminative features. The predictive model performed with an overall Area Under the Curve of 98%, high overall precision (88%), recall (88%), and F1 scores (88%) in the test group, and good Label Ranking Average Precision score (0.95) in a subset of neuropathologically assessed patients. The results of MUQUBIA were explained by the SHapley Additive exPlanations (SHAP) method. The MUQUBIA algorithm successfully classified various dementias with good performance using cost-effective clinical and MRI information, and with independent validation, has the potential to assist physicians in their clinical diagnosis

    Social cognition impairment in genetic frontotemporal dementia within the GENFI cohort

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    A key symptom of frontotemporal dementia (FTD) is difficulty interacting socially with others. Social cognition problems in FTD include impaired emotion processing and theory of mind difficulties, and whilst these have been studied extensively in sporadic FTD, few studies have investigated them in familial FTD. Facial Emotion Recognition (FER) and Faux Pas (FP) recognition tests were used to study social cognition within the Genetic Frontotemporal Dementia Initiative (GENFI), a large familial FTD cohort of C9orf72, GRN, and MAPT mutation carriers. 627 participants undertook at least one of the tasks, and were separated into mutation-negative healthy controls, presymptomatic mutation carriers (split into early and late groups) and symptomatic mutation carriers. Groups were compared using a linear regression model with bootstrapping, adjusting for age, sex, education, and for the FP recognition test, language. Neural correlates of social cognition deficits were explored using a voxel-based morphometry (VBM) study. All three of the symptomatic genetic groups were impaired on both tasks with no significant difference between them. However, prior to onset, only the late presymptomatic C9orf72 mutation carriers on the FER test were impaired compared to the control group, with a subanalysis showing differences particularly in fear and sadness. The VBM analysis revealed that impaired social cognition was mainly associated with a left hemisphere predominant network of regions involving particularly the striatum, orbitofrontal cortex and insula, and to a lesser extent the inferomedial temporal lobe and other areas of the frontal lobe. In conclusion, theory of mind and emotion processing abilities are impaired in familial FTD, with early changes occurring prior to symptom onset in C9orf72 presymptomatic mutation carriers. Future work should investigate how performance changes over time, in order to gain a clearer insight into social cognitive impairment over the course of the disease

    Energy performance of opaque building elements in summer:Analysis of a simplified calculation method in force in Italy

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    The Italian technical standard for calculation of building energy needs in summer allows a monthlyaverage method, in which solar gains through opaque building elements are evaluated distinguishingbetween dark, intermediate or light-colored surfaces, and a fixed value of solar absorptance is assigned toeach surface category. The method is aimed at ease of operation, but its steady-state calculation approachmay not allow taking into proper account dynamic effects due to thermal inertia. Moreover, roofingsolutions typical of Italy such as roof tiles, sealing membranes or painted sheet metal panels can showsimilar colors, but significantly different values of the solar absorption coefficient. On the other hand, aneasy to apply calculation method may enable most designers of the building sector to take advantage ofsolutions for control of solar gains such as cool roofs and cool colors, thus favoring their dissemination.In this paper, the calculation method currently in use in Italy is briefly presented, with the focus onthe role of opaque building elements. Either the accuracy of steady-state calculation or the reliabilityof the color-based evaluation approach is then discussed, analyzing by numerical simulation the actualdynamic behavior of most common types of roof element

    Design of ceramic tiles with highsolar reflectance through the development of a functional engobe

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    Roofing solutions with high capacity to reflect incident solar radiation, the so-called cool roofs, can provide an effective answer to summer overheating of either individual buildings or whole urban areas. Nowadays, commercial cool roofs products are mainly represented by organic membranes and coatings, but ceramic tiles can represent an interesting alternative or complement in view of their low maintenance cost. In this work, it is illustrated how a high reflectance engobe can affect in a positive way the solar reflectance of a glazed tile thanks to the introduction of suitable raw materials and pigments. The reflectance was in fact found to be affected by either the support, the mineralogical composition, the engobe thickness or the glaze. The procedure through which the glazed tile is developed and tested is discussed, in the perspective of production through commonly used industrial processes

    Isola di calore e surriscaldamento estivo: cool colors in laterizio

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    La riflettanza solare delle coperture varia a seconda del tempo e del luogo di esposizione ed \ue8 influenzata dai fenomeni naturali. I manti in laterizio si dimostrano un eccellente candidato, in funzione dell\u2019edilizia ad alta efficienza energetica, sia per il contrasto dell\u2019isola di calore urbana che per comfort indoor e la limitazione dei consumi estiv
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