350 research outputs found

    Bio-based building components: A newly sustainable solution for traditional walls made of Arundo donax and gypsum

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    To contribute to the use of bio-based materials in the building sector, a novel bio-based wall panel, with a high thermal performance level, is proposed in this work. The panel is based on an ancient rural technique, widely diffused in southern Italy, which makes use of Arundo donax L. canes combined with gypsum plaster to build walls and ceilings of rural buildings. The enhancement of the thermal capacity of these panels by means of the introduction in the canes of a natural wax oleogel (WO) is proposed in this paper. A specific experimental campaign aiming at the comparison of traditional and innovative panels was carried out to assess the enhanced thermal performance of the proposed solution. The maximum value of heat flow absorbed from the panel with WO was 61.08 W/m(2) around a mean panel temperature of 24 & DEG;C, corresponding to the melting temperature range of the WO. The panel without WO at the same temperature absorbed an incoming heat flow of 34.64 W/m(2) which is about 57% of the panel with WO. The panel with WO released at a temperature of about 27.5 & DEG;C, a heat flow of 43.42 W/m(2). At the same temperature of about 27.5 & DEG;C, the panel without WO released a heat flow of 34.38 W/m(2) which is about 80% that of the panel with WO. The results highlighted that the addition of natural WO has enhanced the thermal capacity of the panel facilitating heat dissipation through the borders. These characteristics make the panel a suitable component for internal partitions of controlled temperature zones such as residential rooms, storage food areas, livestock buildings, and where it is necessary to obtain a constant environmental temperature. In particular, the null or low toxicity of the panel's materials allows for partition use, also in hygienically safe environments

    Developing a 3D City Digital Twin: Enhancing Walkability through a Green Pedestrian Network (GPN) in the City of Imola, Italy

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    Predominantly, dense historical cities face insufficient pedestrian-level greenery in the urban spaces. The lack of greenery impacts the human thermal comfort on the walking paths, which contributes to a considerable reduction in pedestrian flow rate. This study aims at developing a model to assess pedestrian-level thermal comfort in city environments and then evaluate the feasibility of creating a green pedestrian network (GPN). Imola, as a historical city in Italy with a compact urban pattern, is selected as the case study of this paper. To accomplish this, a three-dimensional digital twin at city scale is developed for the recognition of real-time shade patterns and for designing a GPN in this city. The 3D model of the proposed digital twin is developed in the Rhinoceros platform, and the physiological equivalence temperature (PET) is simulated through EnergyPlus, Honeybee, and Ladybug components in grasshopper. This study provides the city with a digital twin that is capable of examining pedestrian-level thermal comfort for designing a GPN based on real-time PET in the compact urban morphology of Imola. The PET model indicates that during the hottest hour of the 25th of June, pedestrians in open spaces can experience 3  C more than on narrow shaded streets. The results are validated based on in situ datasets that prove the reliability of the developed digital twin for the GPN. It provides urban planners and policy makers with a precise and useful methodology for simulating the effects of pedestrian-level urban greenery on human thermal comfort and also guarantees the functionality of policies in different urban settings

    A comparison of energy and thermal performance of rooftop greenhouses and green roofs in Mediterranean climate: A hygrothermal assessment in WuFi

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    In urban areas, a considerable proportion of energy demand is allocated to buildings. Since rooftops constitute one-fourth of all urban surfaces, an increasing amount of attention is paid to achieving the most efficient shapes and component designs compatible with every climate and urban context, for rooftops of varying sizes. In this study, three types of rooftop technologies, namely insulated, green roof, and rooftop greenhouse, are evaluated for energy and thermal performance using computer simulations. Water surface exposure, absorption, and intrusion are the three important factors in the calculation of hygrothermal models that impact energy consumption and building envelope performance; however, a few studies are specifically focused on providing realistic results in multi-dimensional hygrothermal models and the assessment of the impact of moisture in roofing solutions. This paper aims at evaluating the performance of three different roofing technologies through a two-dimensional hygrothermal simulation in software WUFI. To accomplish this, a precise localized microclimate model of a complex urban context on the scale of a neighborhood was employed to evaluate the cooling and heating loads of the buildings, the impact of the water content in the green roof on the thermal behavior of the roof surface, and the feasibility of designing a building with nearly zero cooling needs. A two-story building in the city center of Bologna, Italy is modelled. Simulation results have shown that during the cooling period, the performance of the designed rooftop greenhouse is the most effective by 50% reduction in cooling loads. Besides, the impact of moisture in green roofs has been detected as a negative factor for thermal and energy performance of the building in the Mediterranean climate. The results ultimately highlighted the capability of passively-designed rooftop greenhouses to create a building with nearly zero cooling needs

    Turning agricultural wastes into biomaterials: Assessing the sustainability of scenarios of circular valorization of corn cob in a life-cycle perspective

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    Circular economy plays a key role in increasing the sustainability of the agricultural sector, given the countless possibilities of transforming crop residues and recycling precious resources. The maize cultivation process produces a significant amount of residual organic materials, commonly left on the field, as a soil conditioner and source of nutrients even if some parts, such as the cob, play a minor role in these actions. The solutions for the valorization of this remnant depend on economic and environmental factors and the evaluation of the environmental performances of the processes in a life-cycle perspective is important to compare the overall sustainability of the valorization alternatives, maximizing their environmental added value. This work reports the results of Life Cycle Analysis, from cradle-to-gate of corn cob valorized as a raw material in two scenarios: corn cob pellet and corn cob abrasive grits to use as blasting or finishing media. A comparative study has been performed with two products available on the market and with the same functions. The results show that cob-based products have lower impact than those currently used. The work provides indication for evaluating the benefits of turning agricultural wastes in natural-based materials and intends to promote circular economy processes in agriculture production

    Methodology for sensor calibration in agro-industrial facilities

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    The rising need of precision in several sectors, agriculture included, brings to the development of new monitoring systems customised for the specific application. These systems often take advantages of probes offered by the market, however, the integration between market probes and home-built systems, requires tests to validate the recorded measurements.This paper provides a methodology to perform a calibration procedure when the probes fail the validation test.The results show the comparison of the measurements collected by investigated sensors and reference sensor coupled with the application of simple correlation methods can bring to an improvement of the sensor precision as far as to pass the validation test

    Investigation of the impact of additive manufacturing techniques on the acoustic performance of a coiled-up resonator

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    Acoustic metamaterials (AMMs) offer innovative solutions for physics and engineering problems, allowing lighter, multiphysics, and sustainable systems. They are usually studied analytically or numerically and then tested on prototypes. For this reason, additive manufacturing (AM) techniques are a popular way of quickly realising AMMs' innovative geometrical designs. However, AM parameters are often standardised without considering the specific issues of each AMM geometrical shape, leading to a possible mismatch between the analytical (or numerical) and experimental results. In this study, a simple AMM-a coiled-up resonator-has been produced with different AM technologies [fused deposition modeling (FDM), stereolithography (SLA), and selective laser melting and materials (polylactic acid, polyethylene terephthalate glycol, resin, flexible resin, and stainless steel). The sound absorption performance of these samples has been measured in two research labs in Italy and compared with the analytical and numerical calculations. This permitted the identification of the best combinations of AM technologies, their setup, and materials matching the expected results. The SLA/resin combination performed better overall; however, cheaper and more easily manageable samples made with FDM and polyethylene terephthalate glycol can achieve the same acoustic performance through the optimal AM printing setup. It is expected that this methodology could also be replicated for other AMMs

    Microventilation system improves the ageing conditions in existent wine cellars

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    Background and Aims: The importance of indoor environmental conditions in a cellar is well known and continuously investigated. The process of wine ageing consists of several steps, during which temperature (T) and relative humidity (RH) play a fundamental role as the quality of the final product is strongly related to stable and suitable environmental conditions. Critical factors, such as mould growth or wine evaporation, have emerged when ventilation has proved to be insufficient or poorly designed. The limitation of stagnant areas and the homogeneity inT and RH provide for proper wine conservation; however, unwanted local conditions can occur in the zones with insufficient air exchange. Methods and Results: Considering these aspects, a controlled microventilation and monitoring system was installed in a case study cellar, and T and RH were monitored for 1 year. The data have been analysed to investigate criticalities of the environmental conditions. The ventilation was activated in specific critical conditions to increase the homogeneity of the T and RH in the critical zones. The results show that the microventilation system improves the homogeneity of both T and RH without affecting the average values. Conclusions: The study demonstrated the efficacy of the system and indicated possible modifications to improve system performance. Significance of the Study: The system proved to be a useful tool for both improving the environmental conditions and providing useful information to the winemakers about the ageing conditions

    Development of an integrated environmental monitoring protocol for SARS-CoV-2 contamination. Applications at the IRCSS San Martino Polyclinic Hospital in Genoa, Italy

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    Scientific background: Environmental sampling of SARS-CoV-2 is a fundamental tool for evaluating the effectiveness of non-specific prophylaxis measures in counting their spread. The purpose of our work was to evaluate the effectiveness of the different sampling methods in the hospital setting to assess their correlation with the structural, functional, and operational situation of the monitored departments and to define the dynamics of the spread of the virus in indoor environments. Methods: The monitoring was carried out at the San Martino Polyclinic Hospital (Genoa, Italy) in the period from April 2020 to June 2021. The presence of viral RNA in the collected samples was evaluated by qPCR. The infection capacity of the sample collected was also evaluated by an in vitro challenge test on cells sensitive to SARS-CoV-2 infection. Results: The percentage of positivity with respect to the number of tests performed (sensitivity) were bubbler 50%, wipe test 17%, and challenge test 11%. Only 20% of the samples tested positive in the wipe test and 43% of the samples tested positive in the bubbler sampling were also positive in the challenge test. All the positivity obtained was detected at a distance of less than 2\u202fm and height of less than 1.5 from COVID-19 patient. Conclusions: Environmental contamination from SARS-CoV-2 detected at the San Martino Polyclinic Hospital is found lower than similar assessments performed in other hospitals both in Italy and abroad. Our study predicted that environmental monitoring of SARS-CoV-2 must be carried out in an integrated way by not using a single sampling method, as each individual test has a different biological significance and performance. However, the virus detected by wipe test is not a degraded viral fragment but an intact infecting virion, only in a modest percentage of cases
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