Isaac Ajunwa - Academia.edu (original) (raw)

Papers by Isaac Ajunwa

Nigerian Journal of Technological Development, 2021

Emissions from use of fossil fuels have consistently posed significant threat to the environment ... more Emissions from use of fossil fuels have consistently posed significant threat to the environment and wellbeing of man. This has prompted several studies aimed at finding solution to the emissions and their effects. The aim of this research is to investigate the effect of adding pentanol and biodiesel from Moringa Oleifera seed to pure diesel content of 70% by volume. pentanol and biodiesel make up the remaining 30 percent by volume and were also varied, with pentanol percentage being increased from 2 percent to 8 percent so as to carefully monitored the effects of adding pentanol while the Moringa oleifera biodiesel made up the balance for the 30%. These blends were labelled according to the percentage composition of biodiesel and pentanol (B28P2, B26P4, B24P6, B24P6, and B22P8). The physicochemical properties of all blends such as viscosity, density, pour point, acid value and iodine value determined. From the result of the engine performance and emission tests, B24P6 blend has bee...

Arid Zone Journal of Engineering, Technology and Environment, 2020

The need of food preservation cannot be over-emphasised. Crops need to be processed and preserved... more The need of food preservation cannot be over-emphasised. Crops need to be processed and preserved in times of their abundance to ensure for life and specie sustainability in times of scarcity. Flat plate collectors (FPCs) are often made fixed and the positions of reflectors used on them are not normally specified; in this paper, a report of an experimental test of an indirect solar dryer whose FPC is operated manually in a single axis to track the sun is presented. To avoid incurring extra cost on the existing design, the FPC was rather made to be operated manually instead of the automation process. Using the Engineering Equation Solver (EES) and the TRNSYS 16 softwares, the angular positions of reflectors placed east and west on the FPC were simulated for the first quarter months of the year of the experiment – this included the month of the test. This is to ascertain the best positions for the reflectors in other to achieve maximum insolation. For the month of the test, March, the...

Proton exchange membrane fuels cell (PEMFC) is fuel cell that useshydrogen and oxygen as its fuel... more Proton exchange membrane fuels cell (PEMFC) is fuel cell that useshydrogen and oxygen as its fuel and the most interesting thing about this cell is that it only produces liquid water as its main by-product. This makes PEMFCsas one of the promising and interesting sources of power for the future because they are fully in compliance with the environmental policies and goal of this generation. However, commercialization and full harnessing of this novel cell has yet to commence despite showing some strong prospectsand potentials. This may be largely due to the technical issues surrounding the operation of PEMFC. The two main issues that pose serious concern are water and thermal managements. Concerning the water management, two important critical issues that are inter-related involve cell dehydration and water flooding, both of which have adverse effects on the performances of these cells.Subsequently, these concerns draw the attention of the research community, where a large number of...

Applied Energy, 2010

Thermal performance of solar air heater is low and different techniques are adopted to increase t... more Thermal performance of solar air heater is low and different techniques are adopted to increase the performance of solar air heaters, such as: fins, artificial roughness etc. In this paper an attempt has been done to optimize the thermal performance of flat plate solar air heater by considering the different system and operating parameters to obtain maximum thermal performance. Thermal performance is obtained for different Reynolds number, emissivity of the plate, tilt angle and number of glass plates by using genetic algorithm.

Many crops are seasonal in nature around the world; for this reason, there is a sustained need in... more Many crops are seasonal in nature around the world; for this reason, there is a sustained need in finding better ways of processing and preserving them – to avail them in times of their lack and to ensure for their market sustainability. In this work, a natural indirect solarbiomass dryer with automated single axis solar tracking system was constructed and evaluated at the Ahmadu Bello University, Zaria using the meteorological conditions of Zaria, Nigeria. Apart from designing a system that can be used at both fair and adverse weather conditions, to help maximize the solar energy collected on the flat plate collector (FPC) without discomforting the user who may also want to attend to other needs, an automated single axis solar tracking system was incorporated to the flat plate collector (FPC) to help track the sun. The performance of the solar dryer in terms of the moisture content, drying rate, collector efficiency and drying efficiency was evaluated when the FPC was made to track...

Nigerian Journal of Technological Development, 2021

Emissions from use of fossil fuels have consistently posed significant threat to the environment ... more Emissions from use of fossil fuels have consistently posed significant threat to the environment and wellbeing of man. This has prompted several studies aimed at finding solution to the emissions and their effects. The aim of this research is to investigate the effect of adding pentanol and biodiesel from Moringa Oleifera seed to pure diesel content of 70% by volume. pentanol and biodiesel make up the remaining 30 percent by volume and were also varied, with pentanol percentage being increased from 2 percent to 8 percent so as to carefully monitored the effects of adding pentanol while the Moringa oleifera biodiesel made up the balance for the 30%. These blends were labelled according to the percentage composition of biodiesel and pentanol (B28P2, B26P4, B24P6, B24P6, and B22P8). The physicochemical properties of all blends such as viscosity, density, pour point, acid value and iodine value determined. From the result of the engine performance and emission tests, B24P6 blend has bee...

Arid Zone Journal of Engineering, Technology and Environment, 2020

The need of food preservation cannot be over-emphasised. Crops need to be processed and preserved... more The need of food preservation cannot be over-emphasised. Crops need to be processed and preserved in times of their abundance to ensure for life and specie sustainability in times of scarcity. Flat plate collectors (FPCs) are often made fixed and the positions of reflectors used on them are not normally specified; in this paper, a report of an experimental test of an indirect solar dryer whose FPC is operated manually in a single axis to track the sun is presented. To avoid incurring extra cost on the existing design, the FPC was rather made to be operated manually instead of the automation process. Using the Engineering Equation Solver (EES) and the TRNSYS 16 softwares, the angular positions of reflectors placed east and west on the FPC were simulated for the first quarter months of the year of the experiment – this included the month of the test. This is to ascertain the best positions for the reflectors in other to achieve maximum insolation. For the month of the test, March, the...

Proton exchange membrane fuels cell (PEMFC) is fuel cell that useshydrogen and oxygen as its fuel... more Proton exchange membrane fuels cell (PEMFC) is fuel cell that useshydrogen and oxygen as its fuel and the most interesting thing about this cell is that it only produces liquid water as its main by-product. This makes PEMFCsas one of the promising and interesting sources of power for the future because they are fully in compliance with the environmental policies and goal of this generation. However, commercialization and full harnessing of this novel cell has yet to commence despite showing some strong prospectsand potentials. This may be largely due to the technical issues surrounding the operation of PEMFC. The two main issues that pose serious concern are water and thermal managements. Concerning the water management, two important critical issues that are inter-related involve cell dehydration and water flooding, both of which have adverse effects on the performances of these cells.Subsequently, these concerns draw the attention of the research community, where a large number of...

Applied Energy, 2010

Thermal performance of solar air heater is low and different techniques are adopted to increase t... more Thermal performance of solar air heater is low and different techniques are adopted to increase the performance of solar air heaters, such as: fins, artificial roughness etc. In this paper an attempt has been done to optimize the thermal performance of flat plate solar air heater by considering the different system and operating parameters to obtain maximum thermal performance. Thermal performance is obtained for different Reynolds number, emissivity of the plate, tilt angle and number of glass plates by using genetic algorithm.

Many crops are seasonal in nature around the world; for this reason, there is a sustained need in... more Many crops are seasonal in nature around the world; for this reason, there is a sustained need in finding better ways of processing and preserving them – to avail them in times of their lack and to ensure for their market sustainability. In this work, a natural indirect solarbiomass dryer with automated single axis solar tracking system was constructed and evaluated at the Ahmadu Bello University, Zaria using the meteorological conditions of Zaria, Nigeria. Apart from designing a system that can be used at both fair and adverse weather conditions, to help maximize the solar energy collected on the flat plate collector (FPC) without discomforting the user who may also want to attend to other needs, an automated single axis solar tracking system was incorporated to the flat plate collector (FPC) to help track the sun. The performance of the solar dryer in terms of the moisture content, drying rate, collector efficiency and drying efficiency was evaluated when the FPC was made to track...