The use of natural fibre reinforced composites such as flax fibre / polypropylene is in a constant expansion particularly in automotive and marine industries due to their good mechanical properties, low density and thus, lightness, low environmental impact, low cost, recyclability, renewable properties of flax fibres and a minimum energy intake during their process. One of the major challenges of thermoplastic composites for the automotive industry is to manufacture finished parts in a single processing step within a minimum amount of time. For this purpose, a stamping airflow device was specifically developed. It is designed to produce woven comingled composite parts from comingled woven fabrics such as flax/polypropylene in only 200 s. Firstly, preliminary tests and the optimization of processing parameters were performed. Then, a quasi-static mechanical characterization of the formed parts was realized. By using criteria based on mechanical properties, the optimal process parameters such as the level of pressure, temperature, holding time and cooling rate so that to obtain the lowest voids rate were determined. Finally, a comparison of the mechanical properties of parts obtained from using the new manufacturing process and a conventional thermocompression process is presented to demonstrate the interest and the level of performance achieved by this original and fast manufacturing device.

The application of biochar is mostly used to improve soil fertility, water retention capacity and nutrient uptake. The present study was conducted in order to study the impact of biochar at water deficiency conditions on the physiological and biochemical processes of Medicago ciliaris seedlings. Seedlings were cultivated under greenhouse conditions in pots filled with a mixture of soil and sand mixed in the presence or absence of 2% biochar. Plants of uniform size were subjected after a pretreatment phase (72 days) either to low (36% water holding capacity, water potential low) or high soil water potential (60% water holding capacity, water potential high). Pots were weighed every day to control and maintain a stable water holding capacity. In Medicago ciliaris, drought led to a significant reduction in plant growth and an increase in the root/shoot ratio. The growth response was accompanied by a decreased stomatal conductance and a reduction of the net CO2 assimilation rate and water use efficiency. The associated higher risk of ROS production was indicated by a high level of lipid peroxidation, high antioxidant activities and high proline accumulation. Soil amendment with biochar enhanced the growth significantly and supported the photosynthetic apparatus of Medicago ciliaris species by boosting chlorophyll content and Anet both under well and insufficient watered plants and water use efficiency in case of water shortage. This increase of water use efficiency was correlated with the biochar-mediated decrease of the MDA and proline contents in the leaves buffering the impact of drought on photosynthetic apparatus by increasing the activity of enzymatic antioxidants SOD, APX, GPOX and GR and non-enzymatic antioxidants, such as AsA and DHAsA, giving the overall picture of a moderate stress response. These results confirmed the hypothesis that biochar application significantly reduces both the degree of stress and the negative impact of oxidative stress on Medicago ciliaris plants. These results implied that this species could be suitable as a cash pasture plant in the development of agriculture on dry wasteland in a future world of water shortages.