ABSTRACT
This study aims to explore the effects of augmenting the mass proportion of a composite comprising paraffin and beeswax (PBPCM) within plaster, which influences the thermal insulation of a dual wall. This work is primarily based on the thermal properties of the composite material PBPCM/plaster with varying percentages of PBPCM. Various essential parameters, such as density, thermal conductivity, specific heat capacity, thermal diffusivity, and latent heat, were assessed and juxtaposed with those of conventional plaster for the PBPCM/plaster composite material. The evaluation of this composite material was executed through an experimental device on a laboratory scale. The obtained results show that the increase in the mass fraction of PBPCM in the plaster decreased the thermal conductivity of plaster more than 3 times, whereas this increase of the PBPCM fraction in plaster enhances heat retention, specifically in specific heat capacity under constant conditions. Nevertheless, in a dynamic state, thermal effusivity has the lowest value for 50% PBPCM. The recommendation is to utilize 50% PBPCM, as it yields an optimal thermal effusivity, and significant values of specific heat capacity and latent heat have been noted for this percentage of PBPCM, measuring 1263.77 kJ/kg K and 18.9 kJ, respectively. Additionally, an increase in the PBPCM percentage narrows the temperature range suitable for effective thermal energy storage.
ABSTRACT
In this work, we investigated the morphological effect of dichloromethane (DCM) on alfalfa (Medicago sativa) plant. We studied in vitro the influence of its concentration on alfalfa germination. The plants were placed in pots for 15 weeks, and exposed to increasing concentrations of DCM (50 µg L-1 and 84 mg L-1). In addition, we examined the effect of two manures (cow and sheep), which were applied to a contaminated soil, on alfalfa plant growth. The effect of the presence of dichloromethane is obvious even in plant-soil manure system. In fact, in the event of contamination, the soil-cow manure mixture represents the best setting medium for the Alfalfa plant compared to other environments, regardless of the contamination level. Indeed, the presence of two types of manure does not allow the suppression of the inhibitory effect of dichloromethane on the mass of the dry matter of the aerial part which is 18.38% for the cow manure-amended soil and 13.96% for the sheep manure-amended soil.