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This study aims at investigating the effects of three different wheelchair cushion technologies at the patient–wheelchair interface. To this end, eight participants were recruited to remain in an unrelieved seated position on a wheelchair successively equipped with three different cushions (foam, air-cell-based and gel), for a duration of 45 min. Interface pressure, temperature (measured with infrared thermography) and relative humidity were measured at the seat interface, at different timestamps. Experimental results show that foam cushion is significantly more efficient in reducing contact peak pressure (p <.01), while the gel cushion displays higher heat evacuation capabilities. In terms of relative humidity, no significant difference is observed among the three technologies (p >.29): all of them evacuate around only 10% of the total humidity compared to the reference situation (i.e., without cushion). Besides, a complementary numerical simulation corresponding to the steady state of the patient-wheelchair structure clearly highlights the temperature volume field at the underside of the seat, which acts like a thermal barrier and contributes to heat accumulation. Besides, an air flow at the underside of the chair in motion is shown to significantly reduce heat accumulation. [ABSTRACT FROM AUTHOR]

Low impregnation of the fiber when the fiber ratio is high may therefore be responsible for the loss of mechanical properties, but it is not the only reason for Nettle and also for kenaf fibers (a variety of hemp) (Kumar and Das [73]). Vegetal fibers; Nettle fiber Nettle fiber culture Nettle plants are very common under our latitudes. Other fibers treatment used for Nettle fibers in a PLA/Nettle composite The study reported by Yu, Jiang, and Li ([120]) uses two different concentrations of maleic anhydride (MA) to create a Ramie/PLA composite. Keywords: Stinging nettle; polylactic acid; mechanical characteristics; biodegradable; treatment; automotive; : ; ; ; ; ; EN Stinging nettle polylactic acid mechanical characteristics biodegradable treatment automotive ZH : 8205 8229 25 11/21/22 20221220 NES 221220 Introduction Nettle and Ramie both belong to the Urticaceae family, but they are from different genus, (Hassler [54]). Fibers caracteristics according to mechanical properties (Gourier [52]) HT

The paper aims to present a new insulating material based on cork aggregates and cement designed for building applications. Samples are prepared by mixing natural cork aggregates, sand, cement and water. Four cork volume dosages are considered, 0, 25, 50 and 75% (relative to the sand). Samples are characterised in terms of hardened density, compressive and flexural strength, as well as thermal conductivity and hydric properties (moisture content, vapour permeability, moisture buffering value and absorption by partial immersion). Results show that increasing cork granule amount tends to increase moisture retention and buffering value but decreases density, thermal conductivity and mechanical properties. Depending on the cork content, cork concrete mixture can be used as thermal insulator or as a structural component. [ABSTRACT FROM AUTHOR]

Global environmental issues are arising over the developed and developing world. Improving energy efficiency and reducing Green Gases emissions become the key issues in all the economic sectors and, in particular, the building sector that is one of the most energy-consuming. It is, therefore, important to find alternative building materials with low-environmental impact contributing to global sustainability. In that context, this study reports on the performance of sustainable materials produced from natural resources as hemp-concrete or from recycled-waste nonbiodegradable materials including recycled polyethylene terephthalate. Three façades employing three different materials (hemp-concrete, hemp-concrete with brick and recycled polyethylene terephthalate) were investigated in three cities in France (Nancy and Carpentras) and Italy (Perugia) with different climate. The energy performance of each façade was assessed in terms of cooling and heating demands, electrical consumption for a constant flow rate ventilation mode, considering different orientations. The study also shows the effect of window size (10%, 25%, and 40%) on the annual energy consumption. [ABSTRACT FROM AUTHOR]

In this article, a hygrothermal building model, taking into account the building envelope, indoor heat and moisture sources, indoor environment and moisture buffering capacity of interior objects, is presented and validated with the test cases found in the literature. The model is used to study the impact of hemp concrete and the moisture buffer capacity of the interior elements on the prediction of the hygrothermal comfort in the building. The numerical results show that the use of hemp concrete in buildings can ensure good hygrothermal comfort. Besides, taking into account the effect of moisture buffering of indoor objects increases the building performance. Our results also suggest that neglecting moisture transfer through the envelope increases significantly the predicted percentage of dissatisfied indices and reduces the acceptability of indoor air quality during the occupied period. This study also confirmed that the combined relative humidity-sensitive ventilation system and moisture buffering capacity of building envelope and of interior objects is a very efficient way to reduce the heating energy consumption. [ABSTRACT FROM PUBLISHER]

The objective of this work is to study the effect of taking into account interface contact resistance on the prediction of moisture distribution through multilayered building envelope. Therefore, two mathematical models to describe coupled heat and mass transfer in double-layered porous materials have been investigated: one that considers imperfect contact between layers and another that ignores this phenomenon. Both models are one-dimensional and were implemented using finite difference technique with an implicit scheme. Numerical results are presented in terms of moisture distribution for a double-layered wall and compared with the experimental data available in the current literature. The comparison has shown that the model that disregards interface contact resistance between layers cannot predict correctly one-dimensional heat and moisture transfer within double-layered porous materials. The sensitivity analysis of the simulation parameters and the impact of contact resistances at the whole building level are presented in detail and their effect on the whole building level was analysed. Our results suggest that the thermal contact resistance is the most influent parameter on the moisture flux across the hydraulic contact interface. On the whole building level, simulations indicate that taking into account contact resistances had a slight effect on the indoor relative humidity but a noticeable effect on heating input energy. A decrease of 10% in energy consumption is obtained when contact resistances are considered. [ABSTRACT FROM AUTHOR]