Prof. Wilfred I. Okonkwo

My Publications

All Publications

Solar Crop Drying - A Viable Tool for Agricultural Sustainability and Food Security

One of the most important potential applications of solar energy is the solar drying of agricultural products. Losses of fruits and vegetables during their drying in developing countries are estimated to be 30–40% of production. The postharvest losses of agricultural products in the rural areas of the developing countries can be reduced drastically by using well-designed solar drying systems. Solar drying is becoming a popular option to replace mechanical thermal dryers owing to the ...

Journal Link

Research gate link

Google Scholar link



Evaporative cooling: A postharvest technology for fruits and vegetables preservation

The quality and storage life of fruits and vegetables may be seriously compromised within a few hours of harvest unless the crop has been cooled promptly to control deterioration. The major problem during storage is the change in the quality parameters of the produce especially the physical characteristics such as; the color, texture, and freshness in which the price sometimes depend on. In order to extend the shelf life, fruits and vegetables need to be properly stored. Proper storage m...

Journal Link

Research gate link

Google Scholar link



Characterization of a Photovoltaic Powered Poultry Egg Incubator

Poultry egg incubation plays an important role in the overall poultry production system especially during the day old chick development. In Nigeria, poultry production is a lucrative business but lack of commercially owned hatchery machines hinder the expansion and make poultry products for instance day old chicks costly more especially in the south eastern part of Nigeria. Presently, few commercially owned poultry hatcheries in Nigeria are located distance far away in the western and nor...

Journal Link

Research gate link

Google Scholar link



The Influence of Different Solar Drying Systems on the Vitamin Content of Pawpaw (Carica ppaya)

Ripe pawpaw was peeled, chipped and dried. Samples of the pawpaw were dried under four different conditions: open-air sun drying method and by using three different models of integral passive solar dryers which include Green house solar dryer, Sun-tracking solar dryer and Latitudinal box solar dryer. The fresh pawpaw samples and the dried samples were analysed for vitamins A, B1, B2, C and E. The results showed a significant difference in the concentrations of Vitamins A, B1, B2, C and E b...

Journal Link

Research gate link

Google Scholar link



Experimental study of a thermosyphon solar water heater coupled to a fibre-reinforced plastic (FRP) storage tank

The thermal performance of the thermosyphon solar water heater was analyzed to show its applicability in a tropical climate using data of cloudy, sunny and hazy days. The average daily efficiency of the parallel-connected module, ranged between 35 and 40%. Also, an analysis of the temperature storage characteristics of a novel fibre-reinforced plastic (FRP) storage tank was undertaken. The inlet andoutlet positions were determined using the recommendation of Simon and Wenxian [1]: the optional p...

Journal Link

Research gate link

Google Scholar link



EXPLORING THE PHOTO SENSITIVITIES OF Mimosa Pudica FOR SOLAR CELL PRODUCTION

The aim of the research is to investigate the possibility of generating electricity from extract of Mimosa pudica leaves and to design a ‘mimosa accumulator’ to store the energy obtainable from the Mimosa pudica isolates. The leaves were dried in the oven, pulverized to enhance extraction with light petroleum and aqueous methanol. Fractions of chlorophyll a and b were separated. The second half of the pulverized leaves was placed in the muffle furnace to remove organic insulators. The...

Journal Link

Research gate link

Google Scholar link



Development and evaluation of a solar powered rice packaging machine

To enhance the marketability of locally produced rice in Nigeria, a machine for cutting and sealing polythene for rice packaging was developed. The machine incorporates a regulator switch which ensures that current flows to the heating element only when the pedal which operates the sealing is matched. This feature reduces the energy requirement of the machine as well as prolongs the life of the heating element. This energy saving feature makes its adaptability to solar photovoltaic (PV...

Journal Link

Research gate link

Google Scholar link



Solar Enhanced Wastewater Treatment in Waste Stabilization Ponds

One of the most popular off-site wastewater treatment plants used in the tropics is the waste stabilization pond (WSP). Although it has several advantages, its use in urban areas is limited because of its large land area requirement. Hence, this research is aimed at investigating if a solar-enhanced WSP (SEWSP) can increase treatment efficiency and consequently reduce the land area requirement. The SEWSPs of varying sizes, made of a metallic tank with inlet and outlet valves and a solar reflecto...

Journal Link

Research gate link

Google Scholar link



Effect of an Absorptive Coating on Solar Energy Storage in a Thrombe wall system

An analysis is undertaken to show the effects of a range of coating absorptivity values on the improvement of heat transfer across a Trombe wall (which is used for passive solar heating) and to its enclosure. The analysis shows that enhanced heat delivery to the enclosure of a Trombe wall system is feasible with the application of an absorptive coating of a superior nature – characterized by high absorptivity and very low emissivity – on the heat-receiving surface of the wall and thus can be...

Journal Link

Research gate link

Google Scholar link





My Quote


“Just as Houses are made of stones, so is science made of facts.”
Henri Poincare