Ascertaining Optimum Pyrolysis Conditions for Biochar Production from Maple Sawdust

Sawdust is a bi-product from wood processing industries. In the recent time, pyrolysis of organic waste is an emerging technology where biochar can be produced and used for carbon sequestration. In that respect, the aim of the present work was to ascertaining optimum pyrolysis conditions in producing sawdust biochar (SBC) for the said uses. The raw material was collected from Belad furniture industry because of their specialization in furniture work and large volume availability. The proximate and ultimate analysis of 3.56% moisture, 1.49% ash content, 72.32% carbon and 0.19% surphur confirmed its good candidature for biochar production. The pyrolysis experiment was carried out by using six combination each of temperature (400, 450, 500, 550, 600 and 650°C), nitrogen flow rates (0.5, 1.0, 1.5, 2.0, 2.5 and 3.0L/mins) and residence times (10, 20, 30, 40, 50 and 60mins). Analysis of resulted biochar was done according to IBI standard. Results showed that the three factors decrease the yield of biochar at their increasing values. SBC yield being optimum at temperature of 400°C, 10 min residence time and 1.0L/min nitrogen flow rate.

Experimental investigation of water-nitrogen flow in microchannel with high aspect ratio (with the 20 µm gap)

This study is devoted to the experimental investigation of two-phase water-nitrogen flow in the slit microchannel with a gap of 20 µm and a width of 10 mm. The technology of microchannel fabrication has been developed and described in detail. Experiments were conducted in adiabatic conditions. Using a modified schlieren system, four flow patterns have been observed and described: jet, bubble, churn, and annular. Flow pattern map was plotted according to obtained patterns. Moreover, a two-phase pressure drop was measured. Dependencies between two-phase pressure drop and superficial liquid and gas velocities have been investigated.

Construction and Characterization of TiN/Si3N4 Composite Insulation Layer in TiN/Si3N4/Ni80Cr20 Thin Film Cutting Force Sensor

The measurement of cutting force is an effective method for machining condition monitoring in intelligent manufacturing. Titanium nitride films and silicon nitride films were prepared on 304 stainless steel substrates by DC-reactive magnetron sputtering and plasma-enhanced chemical vapor deposition (PECVD). The effects of substrate negative bias and nitrogen flow on the surface microstructures of TiN film were investigated. The smoothness of the film is optimal when the bias voltage is −60 V. X-ray diffraction (XRD) analysis was performed on the samples with the optimal smoothness, and it was found that when the nitrogen flow rate was higher than 2 sccm, the titanium nitride film had a mixed phase of TiN(111) and (200). It is further revealed that the change of peak intensity of TiN(200) can be enhanced by nitrogen flow. Through atomic force microscopy (AFM), it is found that the stronger the intensity of the TiN (200) peak, the smoother the surface of the film is. Finally, the effect of different film thicknesses on the hardness and toughness of the TiN/Si3N4 film system was studied by nanoindentation experiments. The nanohardness (H) of the TiN/Si3N4 film can reach 39.2 GPa, the elastic modulus (E) is 480.4 GPa, the optimal toughness value (H3/E2) is 0.261 GPa, and the sample has good insulation performance. Linear fitting of the film’s toughness to nanohardness shows that TiN/Si3N4 films with higher hardness usually have a higher H3/E2 ratio.

Self-Assembling Flexible 3D-MEAs for Cortical Implants

Flexible Multi Electrode Arrays (MEAs) for neural interfacing reduce the mechanical mismatch between the soft brain tissue and the electrode arrays allowing accurate signal recordings and neural stimulation while reducing inflammatory responses. Many standard manufacturing processes of MEAs are designed for planar structures and the production of three-dimensional structures is challenging. In the present study, shaft structures with one to two circular gold microelectrodes (10 - 20 μm), each on a base polyimide (PI) substrate, were investigated. We describe a fabrication method, with which shafts made from bi-layer PI flip into the third dimension, which is a first step towards spontaneous assembly of electrodes in flexible 3D MEAs for neuroelectronic applications. A lift-up of the shafts was achieved by the contraction of a second PI layer and a steady nitrogen flow during polycondensation. This shrinking PI was structured in pits with a width of 5 - 600 μm. We achieved liftup angles of up to 42 degrees. The shaft structures can be hardened and later be used for neural implantation experiments.