Power-driven piston type multi-crop chipper was designed to improve chipping operation of micro, small-scale and medium (MSMEs) chip processors, to introduce new mechanism different from the existing conventional chippers, and develop a low costs, efficient and easy to operate and maintain chipping machine fabricated out of locally available materials. The machine was driven by 0.5 hp electric motor and was made up of dual chipping section to upscale chipping capacity. It was composed of blade plate and blades, connecting rods, pistons, crankshaft, hopper, discharge chute, chipping collector, frame, machine support, power transmission and pulleys and belt cover. The machine performance was tested using the following parameters: feeding capacity (FC), chipping capacity (CC) and chipping efficiency (CE) as to percentage of whole and damaged chips with acceptable thickness. Outcomes of the test showed that the machine has an overall FC and CC of 139.58 kg.hr 1 and 139.02 kg.hr 1 , respectively. The machine's has a CE of 95.48%. Whole chips obtained were 95.63% and the damaged chips were 4.37% of the total input materials. The developed machine is efficient, easy to operate and maintain. These generally make the machine acceptable for commercialization. It was tested for ripe and unripe cardaba banana (Musa sp.), potato (Solanum tuberosum) and sweet potato (Ipomea batatas).

Original scientific paper https://doi.org/10.2298/TSCI171227214O This paper presents the results of a preliminary experimental study to assess the performance of biomorphic silicon carbide when used for the abatement of soot particles in the exhaust of Diesel engines. Given its optimal thermal and mechanical properties, silicon carbide is one of the most popular substrates in commercial diesel particulate filters. Biomorphic silicon carbide is known for having, besides, a hierarchical porous microstructure and the possibility of tailoring that microstructure through the selection of a suitable wood precursor. An experimental rig was designed and built to be integrated within an engine test bench that allowed to characterizing small lab-scale biomorphic silicon carbide filter samples. A particle counter was used to measure the particles distribution before and after the samples, while a differential pressure sensor was used to measure their pressure drop during the soot loading process. The experimental campaign yielded promising results: for the flow rate conditions that the measuring devices imposed (1 litre per minute; space velocity = 42,000 L/h), the samples showed initial efficiencies above 80%, pressure drops below 20 mbar, and a low increase in the pressure drop with the soot load which allows to reach almost 100% efficiency with an increase in pressure drop lower than 15%, when the soot load is still less than 0.01 g/L. It shows the potential of this material and the interest for advancing in more complex diesel particle filter designs based on the results of this work.