Browsing Articles: Department of Water and Agricultural Resources Management by Author "Gikuru, Mwithiga"
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5 Infrared Drying
Gikuru, Mwithiga; Nindo, Caleb (CRC Press, 2010-07-26)This chapter will present the mechanism, techniques, and advantages of infrared (IR) drying for various food and agricultural products. The propagation of IR radiation from a source (considered as any material at a ... -
Alternative methods of harvesting and storage of grass biomass in a semi-arid region
Gikuru, Mwithiga; Mazwiduma, P.J.; Tsopito, C.M. (Academic Journals, 2012-04-12)Biomass is considered a potential feedstock for many renewable energy production systems and interest especially in grass production has increased markedly in the last two decades. The present work focuses on grass biomass ... -
Analysis of Fish Fillet Drying Rates under Three Solar Energy Drying Systems
Gikuru, Mwithiga; Mwangi, Samuel Gathuki (2009-02-20)A small Box type solar dryer with controllable air inlet was designed and tested. The dryer had a mild steel absorber plate and a polyvinyl chloride (pvc) transparent cover and could be adjusted to allow variation in airflow ... -
Coffee Drying in a Rotary Conduction-Type Heating Unit
Gikuru, Mwithiga; Jindal, V.K. (Blackwell Publishing Ltd, 2004-06-01)Parchment coffee (Arabica) was dried from an initial moisture content of about 90% to 10% dry basis (db) in a recirculating rotary conduction type heating unit at controlled plenum temperatures of 100, 120 and 140C or ... -
Comparison of a gas fired hot-air dryer with an electrically heated hot-air dryer in terms of drying process, energy consumption and quality of dried onion slices
Gikuru, Mwithiga; EL-Mesery, Hany S. (Academic Journals, 2012-08-14)Onion slices were dried in either a gas-fired hot air dryer or an electrically heated hot air dryer at air temperatures of 50, 60 or 70°C, and at air flow velocities of 0.5, 1.0 or 2.0 m/s. Records of the drying rates and ... -
The drying kinetics of kale (Brassica oleracea) in a convective hot air dryer
Gikuru, Mwithiga; Olwal, Joseph Ochieng (Elsevier, 2005-12-31)The effect of air temperature and sample thickness on the drying kinetics of kale was investigated using a convective air dryer at a fixed airflow rate of 1 m/s and drying air temperatures of 30, 40, 50 and 60 °C. The ... -
The drying of onion slices in two types of hot-air convective dryers
Gikuru, Mwithiga; El-Mesery, Hany S. (Academic Journals, 2012-08-07)Drying experiments were carried out using two types of convective hot-air dryers such that the hot air passed perpendicularly through a thin layer of onion slices in one dryer while the air passed parallel to the thin layer ... -
Effect of moisture content on the physical properties of three varieties of sorghum seeds
Gikuru, Mwithiga; Sifuna, Mark Masika (Elsevier, 2006-08-31)Three sorghum varieties (Kari-mtama, Serena and Seredo) were obtained from the Kenya Agricultural Research Institute and reconditioned to moisture contents ranging from 13.64% to 21.95% db. The reconditioned grain kernels ... -
Evaluation of the effect of ripening on the sensory quality and properties of tamarillo (Cyphomandra betaceae) fruits
Gikuru, Mwithiga; Mukolwe, Michael Inzoberi; Shitanda, Douglas; Karanja, Paul Nyota (Elsevier, 2007-03-31)Tamarillo (Cyphomandra betaceae) fruits were sourced from a single farmer from the Central province of Kenya soon after harvesting. The fruits were then cleaned and sorted in order to remove all immature and damaged fruits. ... -
Humidity Control System for Wine Maturation Structures
Gikuru, Mwithiga; Magama, P.; Hlophe, M. (2013-12-13)Abstract. Fogging systems can be used to maintain the high humidity required in wine aging structures at acceptable levels during the day and as long as temperature inside the wine maturation store is rising. However, as ... -
Mathematical Modelling of Thin Layer Drying Kinetics of Onion Slices Hot-air Convection, Infrared Radiation and Combined Infrared- Convection Drying
Gikuru, Mwithiga; EL-Mesery, Hany S (AENSI Publisher, 2014)Onion slices were dried in convection hot-air, infrared radiation and combined infraredconvection hot air dryers. A systematic experimental design was applied to analyse drying kinetics due to the effect of type of dryer, ... -
Mechanical expression of oil from grated and preheated coconut meat Botswana Journal of agricultural sciences
Gikuru, Mwithiga; Fondo, Emanuel Chengo (2015)Coconut oil was extracted from grated coconut using a hydraulic pressing method after the coconut gratings were preheated at heating medium air temperature in the range of 30-90oC and heating durations ranging from zero ... -
Performance of a convective, infrared and combined infrared-convective heated conveyor-belt dryer
Gikuru, Mwithiga; El-Mesery, Hany S. (Springer, 2015-05)A conveyor-belt dryer was developed using a combined infrared and hot air heating system that can be used in the drying of fruits and vegetables. The drying system having two chambers was fitted with infrared radiation ... -
Performance of a convective, infrared and combined infraredconvective heated conveyor-belt dryer
Gikuru, Mwithiga; El-Mesery, Hany S (Association of Food Scientists & Technologists, 2015-05)A conveyor-belt dryer was developed using a combined infrared and hot air heating system that can be used in the drying of fruits and vegetables. The drying system having two chambers was fitted with infrared radiation ... -
Performance of a solar dryer with limited sun tracking capability
Gikuru, Mwithiga; Kigo, Stephen Njoroge (Elsevier, 2006-05-31)A small solar dryer with limited sun tracking capabilities was designed and tested. The dryer had a mild steel absorber plate and a polyvinyl chloride (pvc) transparent cover and could be adjusted to track the sun in ... -
Physical changes during coffee roasting in Rotary Conduction‐Type Heating Units
Gikuru, Mwithiga; Jindal, V.K. (Blackwell Publishing Ltd, 2003-08-23)Coffee beans were roasted in a rotary conduction-type-heating unit under constant heating surface or product temperatures ranging from 200 to 240C or 170 to 210C, respectively. the roasting duration was varied from 0 to ... -
The potential for second generation bio-ethanol production from agro-industrial waste in South Africa
Gikuru, Mwithiga (Academic Journals, 2013)There has been a sustained and growing interest in the production of liquid fuel from biomass in recent years. South Africa is a large producer of sugar, maize and wheat among other agricultural products that release big ... -
Potential of nightsky nocturnal radiative cooling as a fresh produce preservation method
Gikuru, Mwithiga; Kirui, Anthony C. (2007-07-30)Abstract: The change in water temperature in horizontally placed pans exposed to the night-sky radiation was monitored at night between the hours of 8:00pm and 6:00am. The effect of varying the quantity of water in the pan ... -
Research trends in modeling, optimization and control of the drying operation
Gikuru, Mwithiga (2007)Drying food is an extremely sensitive operation that requires the proper monitoring and control of the heating medium temperature as well as the length of time that the product is exposed to this temperature. Since the ... -
Specific Energy Consumption of Onion Slices During Hot-air Convection, Infrared Radiation and Combined Infrared-Convection Drying
Gikuru, Mwithiga; EL-Mesery, Hany S. (AENSI Journals, 2014)Total energy requirement and specific energy consumption for drying of onion slices were evaluated using various drying methods including hot-air convection, infrared radiation and hot air convection-infrared combination ...