The impacts of COVID-19 pandemic on the hygrothermal environment of our homes

In 2020 the residential sector witnessed a complete transformation of the way people live and occupy the spaces. Indeed, different Countries introduced total lockdowns as a measure to contain and prevent the spread of COVID-19, forcing people to stay at home. These measures impact the indoor hygrothermal environment: higher internal thermal loads and moisture generation rate may create the perfect situation to support mould growth. This project aims to understand the impacts of increased work-from-home practices on the hygrothermal performance of residential buildings. The assessment uses a two-step methodology: firstly, whole building transient simulations (software trnsys) are used to generate the indoor temperature and humidity profiles, secondly hygrothermal transient simulations (software WUFI) are used to quantify the risk of mould growth. This research reveals the inadequacy of current design and construction practices to support flexible occupation patterns.

Conservation of Contemporary Artworks Made with Soap and Research on the Appropriate Hygrothermal Environment

Various materials, depending on the personality of the artist, are required for contemporary art. Thus, it is necessary to decipher the expressive intentions of the artist and characteristics of the materials required for the conservation of such art. The purpose of this study is to analyze the causes underlying the deterioration of sculptures made from soap and to determine the ideal hygrothermal environment required to stably exhibit and store these artworks. Furthermore, we aim to maintain the long-term structures of the artworks in accordance with the changing expressions and intentions of the artist. Our analysis confirmed that the extracts of the soap sculptures were composed of glycerin and that the sculptures were sensitive to humidity. Moreover, we determined that a relative humidity (RH.) of approximately 60~65% made for an appropriate hygrothermal environment required to preserve the sculptures. We also preserved each work in various ways by applying appropriate preservation treatment, and found that the optimum preservation environment for soap sculptures was a temperature of 20±2°C and a RH. of 60±5%.

Thermomechanical Buckling Analysis of the E&P-FGM Beams Integrated by Nanocomposite Supports Immersed in a Hygrothermal Environment

Due to the widespread use of sandwich structures in many industries and the importance of understanding their mechanical behavior, this paper studies the thermomechanical buckling behavior of sandwich beams with a functionally graded material (FGM) middle layer and two composite external layers. Both composite skins are made of Poly(methyl methacrylate) (PMMA) reinforced by carbon-nano-tubes (CNTs). The properties of the FGM core are predicted through an exponential-law and power-law theory (E&P), whereas an Eshelby–Mori–Tanaka (EMT) formulation is applied to capture the mechanical properties of the external layers. Moreover, different high-order displacement fields are combined with a virtual displacement approach to derive the governing equations of the problem, here solved analytically based on a Navier-type approximation. A parametric study is performed to check for the impact of different core materials and CNT concentrations inside the PMMA on the overall response of beams resting on a Pasternak substrate and subjected to a hygrothermal loading. This means that the sensitivity analysis accounts for different displacement fields, hygrothermal environments, and FGM theories, as a novel aspect of the present work. Our results could be replicated in a computational sense, and could be useful for design purposes in aerospace industries to increase the tolerance of target productions, such as aircraft bodies.