Effect of Wood Waste on Acoustic and Magnetic Properties of Composite Bricks and Correlation between Sound Velocity and Magnetic Induction in These Bricks

In the present study, kambala (botanical name: Chlorophora excelsa and Chlorophora regia) wood wastes were incorporated into stabilized earth bricks in order to test their acoustic insulation capacity of the walls;leading to better waste management from the timber industry. Two methods have been applied to determine the influence of the wood waste content in the stabilized earth bricks, on the weakening of the level of noise reception coming from the environmental medium, in an apartment built with composite bricks (earth + wood chips + cement). This influence has also been analyzed on the magnetic field induced by these bricks. The results showed that the level of sound reception through these bricks decreases with increasing wood waste content regardless of the method used (from 110 dB to 68 dB, respectively for Φb = 0% and Φb = 8%). The kambala wood waste in cement-stabilized clay bricks induces a magnetic field that increases with the wood waste content;the high contents of the wood chips causing an increase in the magnetic permeability of the composite medium. The correlation between the noise level and the magnetic field of the bricks shows that the noise level declines with increasing magnetic induction of the bricks.

Modeling of the Saltwater Intrusion Using the Level Set Method. Application to Henry’s Problem

The salt intrusion phenomenon is caused by overexploitation of aquifers in coastal areas. This physical phenomenon has been the subject of numerous studies and numerous methods have been proposed, with the aim of protecting the quality of the water in these aquifers. This work proposes a two-dimensional saline intrusion model using the sharp interface approach and the level set method. It consists of a parabolic equation modeling the underground flow and a hyperbolic Equation (the level set equation) which makes it possible to track the evolution of the interface. High-order numerical schemes such as the space scheme WENO5 and the third-order time scheme TVD-RK were used for the numerical resolution of the hyperbolic equation. To limit the tightening of the contour curves of the level set function, the redistanciation or reinitialization algorithm proposed by Sussma et al. (1994) was used. To ensure the effectiveness and reliability of the proposed method, two tests relating to the standard Henry problem and the modified Henry problem were performed. Recall that Henry’s problem uses the variable density modeling approach in a confined and homogeneous aquifer. By comparing the results obtained by the level set method with reinitialization (LSMR) and those obtained by Henry (1964), and by Simpson and Clement (2004), we see in the two test cases that the level set method reproduces well the toe, the tip and the behaviour of the interface. These results correspond to the results obtained by Abarca for Henry’s problem with constant dispersion coefficients. The results obtained with LSMR, reproduced the interface with a slight spacing compared to those obtained by Henry. According to Abarca (2006), this spacing is due to the absence of the longitudinal and transversal dispersion coefficients in the model.