ABSTRACT The broad objective of this research was to recover exhaust gases thermal energy from internal combustion engines for use in other applications. The specific objectives were: to determine the amount of thermal energy lost through exhaust gases at various engine speeds and loads; to determine the amount of energy recovered from exhaust gases at various engine speeds and loads; and to simulate the amount of maize that could be dried with the recovered energy. The experimental set-up c...
ABSTRACT Producing enough food in Kenya to better feed people and generate adequate income for the farmers is a great challenge. This challenge is likely to intensity, with a population that is projected to increase to 66.3 million in 2030. Scarce water resources and growing competition for water will be reduce its availability for irrigation, which necessitating major changes in irrigation management and scheduling in order to increase the efficiency of use of water that is allocated to agr...
ABSTRACT The conversion of forest land to agricultural land and urban settlement usually increases soil erosion, and volume of storm runoff in a catchment. In Kenya, the rural communities are encroaching into the humid and marginal areas to open up new lands for agricultural production and settlement. These changes have led to environmental degradation, which has negatively altered the hydrologic regimes of many catchments in Kenya. The Wundanyi River catchment is one of the catchments that ...
ABSTRACT The availability of egg products for consumption is hindered by spoilage and breakages during processing. Forced convection drying serves as one of the methods of solving these challenges. However, the influence of temperature, airflow rate and slice thickness on forced convection drying of eggs is inadequately documented. Therefore, drying of eggs was investigated under forced convection process. The mode of airflow and the food material was the continuous concurrent type. Raw eggs...
ABSTRACT Most stoves based on the principle of micro gasification have improved thermal efficiencies with low emissions, however, knowledge on the effect of the stove operation at different air flow rates on thermal efficiency, fire power, emissions, specific fuel consumption and burning rate is scarce. The main objective of this research was to evaluate performance a micro gasifier cook stove. An experimental forced draft cook stove was therefore developed using the available materials base...
ABSTRACT Sorghum threshing in Kenya is characterized by high grain breakages and accounts for grain loss of 4% of total production. Existing threshing methods are time consuming and yield a low throughput. Grain losses mainly occur due to grain damage and incomplete removal of grains from panicles. In order to reduce the losses, optimal levels of machine and operational parameters influencing threshing need to be established. A prototype spike tooth sorghum thresher was therefore developed u...
ABSTRACT Change in land use has a direct effect in catchment hydrologic response. It is caused by human intervention to enhance and diversify their livelihood needs, and at the same time get economic benefits from the land resources. These interventions result in changes in surface runoff, soil erosion and sediment yield among others. If the change in land use is not well managed then it will affect the quantity and quality of water resources as well as production potential of the land. Base...
ABSTRACT Crop production is influenced by on-site soil moisture availability and application of water conservation methods for dry areas. This research explored the interactive effects of spate irrigation as an application method and the soil moisture conservation techniques. The objective of this research was to analyze the effectiveness of soil moisture conservation techniques and its correlation to water productivity for sorghum production under spate irrigation. The soil water holding ca...
ABSTRACT The design of an irrigation canal is intended to ensure that water is conveyed with minimal erosion and sedimentation. The underground canal in Southwest Kano Irrigation scheme was designed to meet these conditions but over time it has been silted up to the extent that its conveyance capacity has significantly dropped. The sediment control structure at the inlet can only prevent bedload, consisting of large sediments, from entering the canal but cannot prevent entry of fine suspende...
ABSTRACT Drought is acritical stochastic natural disaster that adversely affects water resources, ecosystems and people. Drought is a condition characterized by scarcity of precipitation and/or water quantity that negatively affects the global, regional and local land-scales. At both global and regional scales, drought frequency and severity have been increasing leading to direct and indirect decline in water resources. For instance, increase in drought severity and frequency in the upper Ta...
Some physical and mechanical properties of two Nigerian beniseed accessions (Yandev-55 and E8) were determined at 5 moisture content levels of 5.3, 10.6, 16.1, 22.4, and 28.3 per cent (wet basis). These were used as inputs into designing a beniseed oil expeller, as available ones could not perform effectively with the seed. The determined physical properties were linear dimensions, size, sphericity, bulk and true densities, porosity, thousand kernel weight and coefficient of friction betw...
ABSTRACT The traditional system of producing crops using soil (geoponics) is currently facing major challenges resulting in food deficits. An alternative is the adoption of soil-less culture (hydroponics) which is regarded as key in increasing production of vegetables, herbs and ornamentals. The study aimed at preparing a hydroponic medium from black cotton soil and rice husks. The process entailed moulding, firing, size reduction and performance evaluation. The aggregates were evaluated on ...
ABSTRACT A research was carried out at the Ngongongeri Farm Kenya to determine effects of tillage depth and speed on drawbar power and performance of disc and mouldboard ploughs so as to develop a mathematical model that would assist farmers, machinery managers and policy makers to properly match implements to tractors and the size of tractors to import based on soil types and conditions. The implements used were a standard 2-bottom mouldboard plough and a 3-bottom disc plough. Tillage depth...
ABSTRACT Land use/cover change alters the hydrologic response of river catchments. The response depends on the soil characteristics such as; infiltration capacity, porosity, organic matter content and bulk density. Understanding the effect of the land use change on soil hydrologic response in Upper Njoro River catchment is crucial for formulation and adoption of proper soil and water conservation techniques for increased agricultural production. Additionally, the characteristics of extreme ev...