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The present study aims at valorizing two residues types of the foodless vegetable biomass which are abundant and very pollutant in Burkina Faso. To do it, first we try to identify the optimal values of chipboard elaboration parameters with kenaf and cotton stems by using a natural binder (the bone glue). Next we proceed to the elaboration of two panels types with optimized elaboration parameters. Besides we determine mechanical and thermal characteristics of elaborated panels with a view of an indoor thermal insulation application. Also it becomes necessary for us to determine by experimenting the thermal conductivity, Young's modulus, Coulomb's modulus, and the water inflation rate, taking into account some elaboration parameters on one hand and the correlation between mechanical and thermal properties on the other hand. Finally, the obtained results are compared with the panels properties values required by ANSI A 208.1-1999 standard.

Rapid growth of mining, construction and industrial activities is supported by automated high-performance machineries with sophisticated mechanism like hydraulic excavators. In this research paper, studies and researches have been carried out on the boom-arm-bucket robot system of a hydraulic excavator used especially on industrial, construction and mining sites. These studies provide general information about the technical specifications of this system. In order to improve the system's performances, finite elements stress analyses have been carried out. The studies begin with the design of the system using CAD (Computer Aided Design) software. Then a static force analysis of each component has been performed to determine the forces applied on them. The drawings were transferred to the finite element stress analysis software and all required steps for the analysis have been executed. The results obtained from the finite elements analysis revealed that the designed components were safe and subject to stress far below the assigned material's yield strength. However, the components were heavy and their weight could have been a disadvantage to their use. Design modifications have been performed in order lighten the components and at the same time to decrease their fabrication cost by decreasing the components thickness and changing the assigned material. These modifications also helped to improve their mobility.

Lately there is a renewed interest in the use of bio-resource materials for the production of ecological, sustainable and inexpensive building materials. Sandwich composite of minimum plastic matrix was manufactured, this was achieved by using the Thermoforming process in two steps. In the first step, the core layer was made when thermo pressed 100% hemp Shive particles under a high pressure. The second step was accomplished by wrapping the core layer with two thermoplastic composite layers of 60% of hemp tissue and 40% recycled Polystyrene. Interestingly, through the first step, elevated temperature treated the core surface (hydrophilic) and gave it greater adherence to the Polystyrene matrix (hydrophobic). Mechanical properties of this proposed sandwich composite of 80 % bio-resource were approximately four times of the Polystyrene resistance. Furthermore, the microscopic study was performed to investigate the bonding of the different components, especially for the binderless core layer. Each individual layer and the sandwich form were mechanically investigated, and the finite element method, via ANSYS, was used to illustrate the stresses in the sandwich structure.