Arid Zone Journal of Engineering, Technology and Environment (AZOJETE)
Not a member yet
627 research outputs found
Sort by
Development of an indigenuous rice thresher in Nigeria
No full textRice threshing in Nigeria remains a problem to the average peasant farmer. The techniques for threshing rice are still the traditional method of hand beating. This method is laborious, time wasting and not economical. Aalso the commonly available rice threshers are the imported ones which are not affordable to amjority of the farmers. In an attempt to address this problem, a rice thresher/cleaner was designed, fabricated and evaluated. Physical properties of Faro 51 rice such as length and breadth of grain, grain/straw ratio and moisture content were studied. The thresher was evaluated in terms of threshing efficiency, cleaning efficiency and percentage grain loss. At an average moisture content of 13.83% (wet basis), and design cylinder speed of 556rpm, test results reveal that the thresher has a threshing and cleaning efficiencies of 98.01 and 99.32% respectively and total percent losses of 4.78%. The thresher has an output capacity of 267.9 kgh-
Susceptibility of wheat to water deficit at three growth stages
No full textThe grain yield of wheat (Triticum aestivum L.) to different water deficit levels at three stages of growth was obtained from field measurements conducted at the Aahmadu Bello University Farm, Samaru-Zaria. Also, the suitability of a time-based characterisation of water deficit for crop susceptibility determination was tested against a plant-based one. The plant-based measure of crop water stress, as caused by water deficit, was calculated as the product of relative evapotranspiration deficit and the duration. The crop susceptibility was the relative grain yield reduction due to a given crop water stress.
The results showed that the level of water deficit determines the relative crop susceptibilities to water stress for the crop growth stages considered. Also, the relationship between time intervals (irrigation frequency as a measure of water deficit) and a plant-based water deficit varied during the crop growth season. Thus, the sole use of a time-based characterisation of water deficit for the determination of crop susceptibilities at defined growth stages is found to be unsuitable. However, since the local farmers may find it difficult to use the more sophisticated plant-based water deficit characterisation, a relationship between the plant-based and time-based water deficit characterisation for the different crop growth stages was established. Therefore, the plant-based water deficit characterisation can easily be estimated using the established relationship and the appropriate irrigation scheduling determined
A method for estimating crop actual evapotranspiration
No full textThe reliability of Rhenals and Bras (1981) model in estimating actual evapotranspiration in Samaru for a wheat crop was tested and result is herein presented. This model incorporates climate, crop and soil characteristics factors in estimating actual evapotranspiration. Actual evapotranspiration values estimated using the model were compared with actual evapotranspiration amounts estimated from open pan evaporation data.
The mean difference between the average aily evapotranspiration obtained by Rhenals and Bras (1981) model and those from open pan evaporation data was 0.20 mmday-1 and was not statistically significant at 0.05 level of significance. The tested model is found reliable in estimating the crop actual evapotranspiratio
A review of the causes of wood deterioration and some preventive measures
No full textThis paper examines the problems and prospects associated with the structural use of wood. The paper reveals that wood deterioration is caused by microbiological and entomological agents and weathering among others. Deterioration due to microbiological and entomological agents is as a result of the actions of bacteria, fungi and insects while weathering is as a result of the actions of water, light and heat. The paper also suggests that the deterioration due to these two main causes can be prevented through the use of naturally durable woods, wood preservatives and site and soil treatments. The paper concluded by observing that wood is the most widely used of all building materials because of its abundance and good workability
Performance evaluation of selected crop yield-water use models for wheat crop
No full textCrop yield-water use models that provide useful information about the exact form of crop response to different amounts of water used by the crop throughout its growth stages and those that provide adequate information for decisions on optimal use of water in the farm were evaluated. Three crop yield models: Jensen (1968), Minhas et al., (1974) and Bras and Cordova (1981) additive type models were studied.
Wheat (Triticum aestivum) was planted at the Institute for Agricultural Research Farm during the 1995/96 and 1996/97 irrigation seasons of November to March. The data collected from the field experiments during the 1995/96 planting season were used to calibrate the models and their stress sensitivity factors estimated for four selected growth stages of the wheat crop.
The ability of the model to predict grain yield of wheat with the estimated stress sensitivity factors was evaluated by comparing predicted grain yields by each model with those obtained in the field during the 1996/97 season. The three models performed fairly well in predicting grain yields, as the predicted results were not significantly different from the field measured grain yield at 5% level of significance
Effects of polyphosphate and vinegar treatment on quality of danbun nama (a traditional Nigerian meat product)
No full textLean meat from the hind quarters of bovine (Bos indicus) and spices were obtaine from Maiduguri Monday Market Ltd. The meat was processed into dambun nama after the meat pieces had been treated with polyphosphate (0.3%) alone, and combination of 0.2% vinegar and 0.3% polyphosphate. Samples were evaluated for quality changes along with the non-treated controls during storage at ambient temperature (28°-37°C). The use of polyphosphate increased (P<0.05) the yield of the product and the taste panellist rated the treated products higher (P<0.05) than the non-treated control in terms of taste and overall acceptability. The bacterial counts were generally low and the addition of polyphosphate and vinegar also decreased the total aerobic plate count during 20 weeks of storage. Staphylococcus, Streptococcus and Bacillus species were the main organisms isolated from the product during storage at ambient temperature
Sensitivity analysis and calibration of the EUROSEM model for application in the northeast arid zone of Nigeria
No full textSensitivity analysis on the European Soil Erosion Model (EUROSEM) was conducted and it was found out that the parameters that affect infiltration of the soil are the most sensitive in the model as far as runoff volume is concerned. These parameters are maximum relative saturation of the soil. The model was calibrated using field data from the northeast arid zone of Nigeria. Calibration of the model was based on varying three parameters (maximum relative saturation, porosity and effective net capillary drive) within their range values until best fit between observed and simulated was achieved. Validation was achieved by comparing predicted runoff volumes with observed data not used in calibration. The model was evaluated using coefficients of efficiency and determination. Coefficients of efficiency of 0.82 and 0.74 in calibration and validation. The summary statistics confirmed that the EUROSEM model could adequately simulate surface runoff on the degraded lands of northeast Nigeria and therefore can be applied to runoff related research in the are