An experimental storage based on the principle of evaporative cooling was designed to evaluate the performance of three natural absorbent fiber materials to be used as cooling pads. The absorbent materials were jute, hessian and cotton waste. The performance criteria included cooling efficiency, material performance and total amount of heat load removed from the evaporative cooler. The results showed that under the no-load condition, the average cooling efficiency was highest for jute at 86.2%, compared to 76.3% for cotton waste and 61.7% for hessian fiber. Materials performance tests results showed that the highest resistance to mold formation was exhibited by hessian followed by cotton waste, while the jute fiber had very poor performance. The heat load determination also showed that products stored in the cooler with jute as water absorbent produced the least heat of respiration, followed by cotton waste and hessian in that order. The total results indicated that jute had the overall advantage over the other materials. However, if the cotton waste surface could be modified to offer larger surface required for evaporation, it would be the best alternative because the jute surface is prone to mold formation.

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In cracking palm nuts by application of appropriate impact energy, one of the predominant factors that would enhance the release of either high percentage of whole or split kernels is the percentage level of moisture content in the nuts. The split kernels encourage rancidity of oil since the oily surface of the kernel is exposed to environmental influence. There is therefore need to study the absorption of water in dried palm nuts as a pointer to condition dried nuts to moisture content range that would enhance the production of whole kernels. In this study, dried Dura and Tenera palm nuts varieties were obtained from a palm oil processing mill, classified based on their minor diameter into three size ranges of small, medium and large sizes. These nuts were further dried to bone dry mass followed by immersion of each size range of nuts into different vessels containing water. The rate of water absorption was monitored at 3-hourly intervals. The data generated were analyzed. The result showed that the rate of water absorption per nut unit area had similar curves pattern as the drying curve established for palm nuts. Models for water absorption process involving the dried palm nut was developed based on basic underlying principles and data generated from experimental runs. The models were then validated; and found to be very useful in describing the water absorption process per nut unit area in a given time; and predicting moisture content of bone dry mass of nut soaked in water and kept at room temperature.

In an attempt to easily determine the desired moisture content at any time (t), of selected freshly harvested roots and tubers (yellow cassava, carrot, cocoyam and yam) of economic importance subjected to drying under unsteady temperature conditions such as sun drying, especially in the rural areas where there is no electricity or funds availability to acquire suitable drying equipment by local farmers; the drying constants based on established model that is anchored on mass of the material at any time t was carried out. In this study, three mass classifications, namely: small, medium and large were prepared for each material and subjected to oven drying at a given temperature till bone dry mass. The experimental values obtained were computed and graphs plotted to obtain the slopes as drying constants of values 0.3114, 0.1092, 0.3736 and 0.3790 for bulk samples of yellow cassava, carrot, cocoyam and yam respectively.