2,667 research outputs found

    Wood fiber vs synthetic thermal insulation for roofs energy retrofit: a case study in Turin, Italy

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    In this paper the thermal performance of synthetic and natural insulation materials under real applications are investigated through an experimental activity as well as numerical simulations. During the refurbishment of two houses in Turin (north – west Italy) one roof was insulated with a natural material (wood fiber panels) and the other one with a business as usual synthetic material (XPS and polyurethane). An experimental activity was carried out, both during summer and winter seasons, and the results were used to validate a simplified model. During winter, as expected, the strongest influence on the global performance is related to the insulation thickness. As far as the summer season performance is regarded, for smaller roof surfaces, as for the analysed case study, no particular difference was noticed between the two solutions. A better control of the indoor air temperature was evaluated for the wood fiber insulation when applied on a large surface of the roof. In order to define the best cost-benefit retrofit solutions, ad-hoc evaluations need to be performed

    Thermal and Optical Properties of a Thermotropic Glass Pane: Laboratory and In-Field Characterization

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    Switchable windows are glazing technologies that exhibit dynamic optical properties and may thus be used to improve the energy performance of buildings. A window system based on a thermotropic glass pane was tested both in the laboratory and by means of an outdoor test cell facility. In this paper the full optical and thermal characterization of this glazing technology is presented. Experiments and data analysis led to the characterization of the behaviour of the thermotropic glazing both when this technology is used alone (single glass pane) and when it is integrated in a multilayer fenestration (a triple glazed unit)

    Natural Fibre and Hybrid Composite Thin-Walled Structures for Automotive Crashworthiness: A Review

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    Natural fibres, valued for their low density, cost-effectiveness, high strength-to-weight ratio, and efficient energy absorption, are increasingly emerging as alternatives to synthetic materials in green composites. Although they cannot fully replace synthetic counterparts, like carbon, in structural applications due to their inferior mechanical performance, combining them through hybridization presents a potential solution. This approach promotes a balance between environmental benefits and mechanical efficiency. Recently, the transportation sector has shifted its focus towards delivering lightweight and crashworthy composite structures to improve vehicle performance, address safety concerns, and minimise environmental impact through the use of eco-friendly materials. The crashworthiness of energy absorbers, typically thin-walled structures, is influenced by several factors, including their material and geometric design. This paper presents a comprehensive overview of recent studies focused on the crashworthiness of fibre-reinforced, thin-walled composites under axial crushing. It explores different aspects, such as their materials, cross-sections, stacking sequences, triggering or filling mechanisms, and the effect of loading rate speed. Emphasis is placed on natural-fibre-based materials, including a comparative analysis of synthetic ones and their hybridization. The primary objective is to review the progress of solutions using green composites as energy absorbers in the automotive industry, considering their lightweight design, crashworthiness, and environmental sustainability

    Experimental Analysis of an Advanced Dynamic Glazing Prototype Integrating PCM and Thermotropic Layers

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    Glazing components are the most challenging element of the building envelope system. The insertion of a Phase Change Material coupled with a thermotropic layer is herewith proposed as an innovative solution aimed at improving the energy performance of the fenestration. The intention is to increase the dynamic features of glazing systems and to enhance their capability of exploiting solar energy – a crucial feature in nearly Zero Energy Buildings. The paper presents the experimental analysis of two prototypes of such a glazing concept and the assessment of their energy performance during the warm season. The samples are installed on an outdoor thermostatic cell facing south, together with a reference triple glazed unit, and continuous measurements of temperatures, irradiances and heat fluxes are performed. In the summer season, when the aim of the glazing system is to reduce the solar gain and to allow daylighting the energy performance is very promising. When compared to the reference technology, both the prototypes are able to reduce to a great extend the direct transmitted solar energy, as well as to smooth the peak indoor surface temperature of the glazing. In particular, one of the two configurations lowers down the solar energy gain under all boundary conditions, while the other configuration presents a slightly worse performance than the other prototype when high solar irradiation occurs. An attempt to measure the thermal transmittance was also carried out and it is shown that the insertion of PCM does not increase the U-value of the component

    Experimental Analysis of an External Dynamic Solar Shading Integrating PCMs: First Results

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    This paper presents the first results of an experimental analysis on dynamic translucent solar shadings with PCM, aimed at demonstrating its potential on reducing internal solar heat gains. The study is focused on the assessment of the thermal performance of the prototype panel during the solid phase of the PCM through an experimental campaign in a test cell facility. The total daily solar heat gains were reduced by more than 50% compared to the non-shaded reference triple glazing unit and the internal surface temperature of the glazing decreased of more than 6 °C during the maximum external incident solar radiation

    NATURWALL© - A Solar Timber Façade System for Building Refurbishment: Optimization Process through in Field Measurements

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    Building renovation is one of the key issues of recent European policies towards energy efficiency. The concept of an opaque, modular and prefabricated vertical façade, made of wood and lightweight components, is proposed in this framework. Naturwall© is an Italian patented project intended for the retrofitting of existing buildings, to improve both the energy performance of the building and its architectural aspect. Different prototypes of the façade were tested during an experimental campaign carried out in outdoor test cells. The here presented results describe the winter and summer behavior of the façade through the use of synthetic indexes i.e. the U-value and pre-heating efficiency

    Lotus Birth Associated With Idiopathic Neonatal Hepatitis

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    In the present case, the infant presented with a complication of LB. There was a close temporal relationship between LB and the onset of clinical symptoms. The baby had persistent jaundice associated with a severe increase in aspartate and alanine aminotransferases without evidence of cholestasis. Recovery occurred spontaneously after the first months of life. Hepatobiliary, hematological, metabolic, endocrine, and genetic disorders were ruled out

    Depression pandemic and cardiovascular risk in the COVID-19 era and long COVID syndrome: gender makes a difference

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    The ongoing COVID-19 pandemic highlighted a significant interplay between cardiovascular disease (CVD), COVID-19 related inflammatory status, and depression. Cardiovascular (CV) injury is responsible for a substantial percentage of COVID-19 deaths while COVID-19 social restrictions emerged as a non-negligible risk factor for CVD as well as a variety of mental health issues, and in particular, depression. Inflammation seems to be a shared condition between these two disorders. Gender represents a potential modifying factor both in CVD and depression, as well as in COVID-19 short- and long-term outcomes, particularly in cases involving long-term COVID complications. Results from emerging studies indicate that COVID-19 pandemic affected male and female populations in different ways. Women seem to experience less severe short-term complications but suffer worse long-term COVID complications, including depression, reduced physical activity, and deteriorating lifestyle habits, all of which may impact CV risk. Here, we summarize the current state of knowledge about the interplay between COVID-19, depression, and CV risk in women
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