Prof. Wilfred I. Okonkwo

My Publications

All Publications

Development of a single stage roselle calyx extractor

An 8-litre capacity roselle calyx extractor was developed with Arduino based temperature controls ranging from 30 to 100?C. Performance evaluation conducted on the extractor showed that efficiency of the extractor increased as the weight of the calyces decreased at constant mass of water which ranged from 55% to 89%. The effect of extraction time (5, 10 and 15 minutes), process temperature (30, 50, 75 and 100?C) and calyx-water mass ratio (1:50, 1:20 and 1:10) on the pH, density and colour of th...

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PERFORMANCE EVALUATION OF A PYRAMIDAL PASSIVE SOLAR DESALINATION SYSTEM IN NIGERIA

Performance evaluation of a pyramidal passive solar desalination system was undertaken atthe National Centre for Energy Research and Development (NCERD), University of Nigeria,Nsukka lat. 6.8oN and long. 7.29oE Nigeria using saline water samples collected from Uburuand Okposi salt lakes respectively. The solar desalination system was constructed with localavailable materials made of wooden materials and rapped in galvanized metal sheet. Thesystem has the capacity of recovering salt from s...

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Optimization of Anthocyanin Extraction from Roselle (Hibiscus sabdariffa) Calyces: RSM, Kinetic Modelling, Mass Transfer and Thermodynamic Studies

Roselle calyces (Hibiscus sabdariffa) are becoming very important in the food and beverage industry, especially because of the presence of anthocyanin which is an antioxidant responsible for their red colour. The effect of processing parameters such as contact time, temperature and calyx-water ratio on the anthocyanin content of roselle calyces extract was studied and optimized along with evaluation of kinetic models, mass transfer and thermodynamic parameters. Extraction kinetics for anthocyani...

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Socio-Economic Importance of Solar Energy Application in Poultry Production System

Solar energy is a renewable, inexhaustible and affordable form of energy that could help mitigate climate change in poultry production systems. Its application as an emerging technology in poultry production systems is not common among the Nigerian poultry farmers. This paper presents a survey of poultry farms in Enugu State, Southeast, Nigeria. The purpose of the survey was to ascertain the status of solar energy application in Poultry production systems in the state. A s...

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Impacts of Climate Change on Environment and the Remedies

World's global climate has been changing for many decades now. Natural events and human activities are the major contributors of climate change. The impacts are manifest through the adverse effects posed on environmental temperature rise, extinction of wild animals, status change in water resources availability, agriculture, vegetation, air quality and sea level. These are critically influenced by climate change and variability. Many studies by the Intergovernmental Panel on Climate Change (IPCC...

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Performance evaluation of mixed mode passive solar stock fish dryer

The performance evaluation of Mixed-Mode Passive Solar Dryer for drying codfish (Gadusmorhua) was conducted. The dryer is comprised of among other things, materials for sensible heat storage to discharge heat during the off-sunshine period. The drying chamber is integrated with a suction device to aid the convective airflow to avoid reversible reaction during the discharge of accumulated moisture. The solar dryer was evaluated with fresh codfish samples at the initial moisture content of 79% (we...

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Numerical modeling of Trombe wall solar chick brooder for optimal poultry production

Poultry brooding requires optimal provision of heat, medication, water and feed on abuilt environment deep litter for day-old chick. This built environment (Trombe wall solar chick brooder) has been developed but has not been numerically modeled and validated. Therefore, numerical modeling, simulation and validation are carried out on Trombe wall solar chick brooder. Predictive linear differential equations based on physical, mathematical principles and relationships governing thermo-physical pr...

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Design, Construction and Performance Evaluation of a Trombe Wall Poultry Day-Old Chick Brooding House

The recent increasing interest shown in passive solar heating is motivated by their capacity of providing thermal comfort and energy saving. Among the passive solar heating, Trombe wall system has aroused great attraction for its simple design. This is because Trombe wall system could be easily adopted in animal husbandry. As a consequence, its use is encouraged in commercial poultry day old chicks production systems. In this study a passive solar heating system using Trombe wall for poultry day...

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Proximate, Microbial and Sensory Properties of Moi-Moi Produced with Crayfish and Grasshopper.

The research assessed the proximate, microbial and sensory properties of moi-moi produced with crayfish and grasshopper (Zonocerus variegatus). Cowpea seed, crayfish and grasshoppers were processed into flours using standard procedures. Cowpea-crayfish flour and cowpea-grasshopper flour were formulated with the ratios: 90:10, 85:15, 80:20 and 75:25 respectively. Proximate properties showed the range of values for Protein: 5.50-12.80, Fat: 5.27-8.07%, Carbohydrate: 28.30-3...

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My Quote


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