Using ecological materials such as raw earth represents an ancestral building practice that has been revisited for modern construction, thanks to its availability, low cost, environmental friendliness, and thermal properties, which offer optimal insulation and thermal comfort. This article explores the development of a new composite based on raw earth reinforced with 15% mussel shells, a by-product of the aquaculture industry, combined with two stabilizers: lime or cement (3%, 5% and 8%), in distinct formulations. This study aims to characterize the chemical and mineralogical composition of the soil and mussel shells and the thermal and mechanical properties of the composites. The results indicate that the gradual addition of lime to the soil-mussel shell mixture decreases dry density, which reduces dry mechanical strength due to increased porosity but enhances thermal properties. Conversely, incorporating cement into the soil-mussel shell mixture improves significantly mechanical properties while limiting the thermal performances.

This study investigates the damping behavior of olive trees under trunk shaking by assessing transmitted acceleration and logarithmic decrement in the soil and tree, as well as the actual shaking, damping, and elastic powers within the tree. The trunk shaker was operated at five attachment heights: 0.4, 0.5, 0.6, 0.7, and 0.8 m. Results revealed that the peak elastic power of 8.8 kW occurred at 0.8 m, after which elasticity declined, indicating that the tree reaches its maximum elastic capacity before inertia dominates. The transmission of acceleration to the root-soil system is influenced by attachment height and trunk diameter, with larger diameters and lower attachment points reducing transmitted acceleration. The highest transmitted acceleration of 30.7 ms- 2 was measured at 0.8 m. Along the x-axis, acceleration progressively increases from the base to the branches, while the y-axis is mostly absorbed by the trunk. Additionally, the logarithmic decrement decreases with distance from the shaker, reflecting greater damping in the trunk compared to the branches. These findings suggest that optimizing attachment height during mechanical harvesting can enhance energy efficiency and minimize damage by improving elastic responses and managing acceleration and damping dynamics.

Lunar in-situ water ice utilization is considered an essential part of the future construction of Lunar Bases. However, the thermal conductivity of lunar regolith without water ice is extremely low, which seriously hinders the thermal mining of lunar water ice. In this study, we proposed a novel approach to optimize the energy ef-ficiency of water ice thermal mining. In this method, a constant temperature heat source with a heating tem-perature selected according to the particle size of water ice was used to slow down the reduction rate of the thermal conductivity of icy soil. Our simulation results showed that the relatively high mining temperature led to the rapid sublimation of water ice near the heat source, reducing the thermal conductivity of the icy soil and the energy efficiency.A relatively low mining temperature decreases the sublimation speed of water ice and reduces energy effi-ciency. The particle size of water ice determined the decreasing rate of thermal conductivity of icy soil, thus affecting its optimum heating temperature. Using a constant temperature heat source at the optimal heating temperature, the energy efficiency of water ice mining could be increased by several orders of magnitude compared with constant power heating.

It is of great significance to realize the in-situ utilization of lunar water ice for the establishment and sustainable operation of the future lunar base. Considering the location of water ice in the lunar polar regions, based on the in-situ thermal mining method, an integrated approach for the water ice recovery was established. The evolution characteristics of average temperature of the icy soil and water vapor collection rate with the mining time were analyzed. The optimal mining temperature for the recovery of water ice was studied. The energy efficiency under various arrangement densities of heating elements was assessed with the optimal number of heating elements determined. The results show that as the mining time increases, for different target mining temperatures, the average temperature of the icy soil rapidly rise at first, and then tend to stabilize. The water vapor collection rates at different target mining temperatures vary greatly due to the difference in saturated vapor pressure of water ice. At high mining temperatures, the sublimation coefficient also significantly affects the process of water vapor collection. The water vapor collection rate with sublimation coefficient being unity is up to 36% larger than that with non-constant sublimation coefficient for the lunar soil under investigation within four earth weeks at the target mining temperature of 240 K. In addition, the increase of the mining temperature increases the water vapor collection rate, and at the same time, the water vapor pressure in the capture tent also increases, which may lead to the instability of the water ice production system. Combining with water vapor collection rate and change rate of water vapor pressure in the capture tent, the temperature of 220 K is obtained as the optimal target mining temperature. Furthermore, for the lunar soil in this work, the energy efficiencies for water ice production with seven and nine heating elements are same, and greater than that with five heating elements. Considering the energy efficiency, the minimum number of heating elements could be determined.