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Water heating experiments were carried out on four different double exposure box-type solar cookers(DEBSCs) containing different heat storage materials (HSMs) (i.e. benzoic acid, stearic acid, palm olein and no HSM) when the base reflectors were opened and closed to solar radiation. The change in temperature of water and HSMs, water heating power, sensible heat efficiency, and the amount of energy stored by the HSMs were estimated. Using the base reflectors, a water temperature boost of 20 oCwas attained without any HSM, while, a boost of around 6-15°C was attained with HSM. Heating power was observed to be higher when the base reflectors were used; with a difference up to 112, 60, 172 and 35 W in the DEBSCs with no HSM, benzoic acid, stearic acid and palm olein respectively. Using a base reflector makes the DEBSCs attain higher SHE. The average energy stored by benzoic acid, stearic acid and palm olein in the DEBSCs without base reflectors were; 178, 461 and 110 kJ respectively, while with base reflectors, the energy stored was; 182, 503 and 245 kJ respectively. The presence and absence of the base reflectors affected the performance of the DEBSCs.

The effect of moisture content on some physical properties of bush mango (Irvingia gabonensis) nut was studied at four moisture levels in the range of 7.52%-20.6% (d.b). Results showed that the length, width and thickness of nut increased from 37.84 to 50.16 mm, 30.23 to 42.62 mm and 19.25 to 28.15 mm respectively, as moisture content increased in the above range. Nut sphericity decreased from 76.2% to 69.5% as moisture content increased. One thousand seed weight, bulk density, true density and angle of repose increased from 6.634 to 9.158 kg, 756.7 to 1095 kg m-3, 984.4 to 1265.8 kg m-3 and 25.3 ° to 38.9° respectively, in the above moisture range. Static coefficient of friction on different surfaces increased in the order of fiber glass (0.278 to 0.394), metal sheet (0.478 to 0.499) and plywood (0.577 to 0.602) as moisture content increased. Regression analysis showed that all properties followed a linear trend with moisture content. [ABSTRACT FROM AUTHOR]

Evaporative cooling occurs when warm and unsaturated air is blown across a wet surface. This study reviews the development of simulation software as a research tool for designing evaporative cooling systems. The simulation incorporates information concerning the effect of the cooling pad length, cooling pad height, cooling pad thickness, air velocity, water flow rate, water temperature, water to air mass flow rate, and number of cooling pad segments in terms of the performance efficiency of the cooling system. The software rapidly produced model data, which was subjected to further analysis for verification and validation during the testing stage. The modelled and experimental data of the saturation efficiency were compared using 4 of the most important statistical parameters, based on a paired sample t-test of an equal variance assumption. The results indicated that there was no significant difference between the software generated data and the experimental data of the Saturation Efficiency on Pad Thickness - mm (p = 0.635), Air Velocity - m/s (p = 0.140), Water Flow Rate - L/min (p = 0.341) and Water Temperature °C (p = 0.567) at α = 0.05 significance level and 95% confidence interval. [ABSTRACT FROM AUTHOR]

The global increase in demand for vegetable oils due to their nutritional, pharmaceutical, and industrial importance necessitates investigation on exploitation of new oil bearing crops. This study was undertaken to determine the influence of processing conditions on physical properties of oil expressed mechanically from African oil bean kernels. Central composite rotatable design of response surface methodology (RSM) at 3‐factors, 5‐levels was adopted; independent variables considered were: moisture content (MC; 8, 10, 12, 14, and 16% dry basis), heating duration (HD; 5, 10, 15, 20, and 25 min), and heating temperature (HT; 50, 70, 90, 110, 130 °C) while dependent variables (physical characteristics) include: oil impurities, density, kinematic viscosity, dynamic viscosity, specific gravity, refractive index, and color; all determined using standard methods. Optimum values were obtained using RSM. Optimum oil quality (0.044%m/m impurity, 0.92 kg/m3 density, 43.86 mm2/s kinematic viscosity, 40.8 mPa s dynamic viscosity, 0.9 specific gravity, 1.469 refractive index, and 7.7 color units) was obtained at 8% db, 11.7 min HD, and 59.3 °C HT. The quality of the expressed oil falls within permissible limits for edible oils and high nutritional importance. The processing conditions influenced the quality of the mechanically expressed African oil bean oil. Practical applications: African oil bean is an underutilized plant with potentials for meeting increasing global demand for vegetable oil for nutritional and industrial importance. The application/usage of oil is dependent on its quality attributes which is otherwise dependent on processing parameters like moisture content, heating duration, and heating temperature. These factors need to be controlled during oil expression processes to actually the optimum conditions that will yield good quality oil. The degree of influence of the parameters on oil quality is a useful data to vegetable oil processors, food, and agricultural engineers. The quality parameters of the oil were determined and compared with international standard parameters. Mathematical models were developed to predict the yield and quality attributes of expressed oil from African oil bean kernels at various processing conditions. [ABSTRACT FROM AUTHOR]

The use of inappropriate equipment to crack bush mango (Irvingia gabonensis) nut to obtain the kernel has adversely affected the processing and utilization of the crop. The manual method of cracking the nut with stone, cutlass or pestle and mortar, is not only slow and risky, but also wasteful. Knowledge of the nut mechanical properties is important in the development of its processing equipment. This study was undertaken to determine some strength or mechanical properties of the nut at different moisture contents under lateral and longitudinal loading orientations, using the Universal Testing Machine (UTM). In the moisture range of 7.52%-20.6% (d.b) under the above loading orientations, results of tests showed that all the strength properties decreased with increase in moisture content. Only the rupture strength increased from 0.0507 to 0.0723 N mm-2 as moisture content increased in the above range, under lateral loading orientation. Loading along the longitudinal axis had higher strength property values than lateral loading. This implies that the nut will be easier to crack when loaded on the lateral axis. These findings will be useful in the development of a cracking equipment for bush mango (Irvingia gabonensis) nut. [ABSTRACT FROM AUTHOR]