Improvement of an existing low cost wooden groundnut sheller

An existing manually operated groundnut sheller was re-designed, fabricated and tested. About 90% of the components of the 18 kg./hr capacity rasp-bar sheller, equipped with a kernelcleaning device, were fabricated using the sawn wood of Cordia millennii. A one-off prototype of the sheller was produced at a total cost of about N4,500.00. Performance evaluation conducted using “Spanish Valencia” groundnut cultivar at 10%moisture content (dry basis) indicated an average shelling efficiency of 76% and a cleaning efficiency of about 82%. Keywords: groundnut sheller, wooden, shelling efficiency, cleaning efficiency Journal of Applied Science, Engineering and Technology Vol. 5(1&2) 2005: 71-7

Compatibility of Calamus deerratus and Lacosperma secundiflorum Rattan Particles with Ordinary Portland Cement

An investigation was conducted to determine the optimum water to cement ratio for a locally manufactured Portland cement for use in wood composites. The effects of pre-processing and calcium chloride (CaCl2) on the compatibility of two rattan canes (Calamus deerratus and Lacosperma secundiflorum) with cement were also assessed using the compatibility factor (CA) approach. An optimum water: cement ratio of 0.45 was obtained. Generally the two rattan species were compatible with cement. The CA factors increased with increasing levels of CaCl2 concentration (65.2% to 101.5% for C. deerratus and 71.2% to 103.5% for L. secundiflorum at 0 to 3% concentrations). Removal of the silified epidermis (pre-processing) had more significant effect (P ≤ 0.05) on the compatibility of C. deerratus with cement than in the L. secundiflorum species. Also, the particles of the Lacosperma species were more compatible with cement than those of the Calamus species probably due to the anatomy and other variations in the two species.Keywords: Rattan, Calcium chloride, cement compatibilit

Effects of selected pre-treatments on the setting of cement composite from two rattan species

The effects of aqueous extraction and removal of silified epidermis from rattan canes on the maximum hydration temperature (Tmax) and setting time (tmax) of two rattan cane species, Calamus deerratus and Lacosperma secundiflorum, mixed with Portland cement were investigated. Tmax ranged from 37.0 to 58.60C and from 43.1 to 56.80C for the C. deerratus and L. secundiflorum composites respectively while tmax was from 3.7 to 26.5 hrs and 7.4 - 25.7 hrs. Aqueous extraction increased the Tmax and reduced the tmax of the rattan-cement mixes while removal of epidermis generally caused reduction in both Tmax and tmax. The two rattan species seemed more amenable to cold than hot water extraction. Although cement inhibition of the Calamus species was greater than that of Lacosperma species, aqueous extraction improved the tmax of the Calamus-cement composite more than Lacosperma-cement composite. Epidermis removal, species, aqueous pre-treatment and their interactions had significant effect on the setting time of the rattan-cement mixes.Keywords: rattan, cement composite, hydration temperature, setting timeJournal of Applied Science, Engineering and Technology Volume9,: 5-1

The effects of pre-treatments, wood-cement ratios and partial cement substitution by gypsum on Prosopis chilensis wood composites

The aim of this work was to study the effects of pre-treatments, wood-cement ratios and partial cement substitution by gypsum on Prosopis chilensis wood composites. Using ASTM D1037-7, the study reveals that the mechanical properties of the composites are improved by the addition of gypsum treatment, and the lower substitution percentages (10, 20 %) are found to improve the compressive strength. Increasing the substitution percentages by more than 20 % causes a reduction in the density of the aggregates, which negatively affects the compressive strength of the cement composites