Advanced Materials Research Vols. 62-64

Abstract: The paper looks into the possibilities of using available renewable resources in rural areas for electric power generation for remote consumers. Based on meteorological data (the hourly wind speed) collected and analyzed for Dapchi, a north eastern rural settlement of Nigeria, coupled with hydrological data of River Kamadougu Gena, the hourly power produced from a hybrid power system comprising of wind and small hydro power systems is evaluated and considered as a supply source to electrical loads of the settlement.

Abstract: 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 rate through the drying chamber. A convectional green house covered with transparent pvc and into which a drying tray stand at a height of 90 cm above the ground was placed made up the second drying method. The rate of air flow through the green house could be controlled by adjusting the opening at either end of the tunnel. The third method of drying which also served as the control is sun drying in which case the drying trays was placed 90 cm above the ground but left unenclosed to allow free flow of ambient air. The air temperature at points just above the drying rack was monitored for all three drying systems under no load conditions from morning to late afternoon. The temperature was also monitored during drying when the trays were loaded with fish of different fillet thicknesses. The rate of loss of moisture was also monitored by weighing the fillets at regular interval until the moisture dropped to 20%, dry basis or lower. The average temperature inside the plenum chamber of the box type solar dryer was found to have a high daily value of 71.1OC although an absolute maximum value of 74.4OC was recorded. This maximum value could be reached on cloudless days between the hours of 13:00 and 1400. The green house recorded a slightly lower average temperature and its peak value occurred latter in the day. Both the green house and the box-type solar dryer had average drying chamber temperatures that were more than 30 centigrade degrees above ambient conditions. Both the box-type and green house type solar dryer could dry thin slices of fish fillet in 1-3 days as opposed to the 7-9 days normally required under sun drying conditions. The quality of the dry fillet was satisfactory and CIE LAB colour values did not change significantly during drying.

Abstract: In consideration to the numerous impacts of coal burning especially in domestic indoor fires, a coal-based composite solid fuel has been developed to immensely reduce gaseous emissions, while at the same time maintaining good heat generation rate. The fuel-type which was produced from a mixture of coal and clay solution yielded its optimum heating properties and minimum emission for a formulation of 2:1 of coal: clay solution (1:2.5 of clay: water) by mass fraction. The calorific value of the pure coal was higher than that of composite coal by a factor 1.2 for the same mass of sample used. The formulated composite solid fuel which was found to compete favourably with pure coal, was also efficient toward gaseous emission reduction when combusted at 400oC than at 800oC.

Abstract: In this paper a motorized solar energy collector system-a driver system that positioned the solar cell panel differently during day-time was design and implemented. The aim is to optimize the amount of solar energy that can be trapped from the sun using a solar cell panel. This is achieved by using a stepper motor, controlled by Atmel AT89C52 microcontroller, to align the panel such that all incident rays strike normal to the panel’s surface thereby maximizing the amount of solar energy that can be trapped from the sun. The alignment is time dependant. This model was implemented and tested and the results proved to be successful in maximizing the energy received from the sun than if the solar panel was fixed at a particular position.

Abstract: The main hindrance to the widespread of solar systems is the cost of the solar collectors. Researchers all over the world have been exploring different means of overcoming this limitation in order to make solar conversion more cost effective. This paper describes an experimental work on optimum seeking position of solar collectors using feedback control theory. Single axis tracking mode is employed together with sun seek sensor for automatic reset. The performance of the tracking collector compares favorably against a fixed collector.

Abstract: This solar conversion system incorporates a suction fan powered by a solar PV module. Located at the outlet of the chamber is the d.c suction fan utilised to achieve forced air circulation without the use of external power supply like grid electricity, fossil fuel and battery. Simple thermal energy balance equations and heat transfer equations were employed in the design of the system. The operational efficiency of the collector is 83.2% and mass flow rate 1.58kg/min, the maximum temperature achieved in the chamber was 58oC. The system was used to dry vegetable, hydrophylum. The capital cost is less than $150.

Abstract: A team of academics produced a Design Brief (DB) to assist architects design a scholarly physical environment for modern engineering education and research. The information gathered from external and internal sources was used to define important themes that the buildings should reflect and hence to arrive at a list of the required spaces. Critical internal and external reviews and budget constraints led to a series of successive refinements of the DB. A design competition was organised for all interested architects in the country to select the architect for the project and consolation prizes were awarded to second and third finalists. The planned development will provide 17900 m2 and 25200 m2 net usable space and estimated gross building area respectively.

Abstract: Recent trends in globalization of business operations and education has increased the need for global teams. These teams face a variety of challenges. This paper discusses the experience of distributed teams made up of participants from the Tokyo Metropolitan Institute of Technology and Stanford University in carrying out a design and development assignment. Challenges faced included differences in culture, in time and experience and the use of distributed information to develop a new product. Better product development demanded at least one face-to-face meeting, setting milestone deadlines and heavy use of electronic media, especially telephone and video conferencing.

Abstract: This research involves measuring maintenance productivity and seeks to measure how maintenance of equipment affects the overall productivity of the company. The Stewart Utility Concept was used along with a scaling factor. Performance measures were identified and their values were obtained. Five productivity ratios were employed to obtain the overall maintenance productivity. Results from the graphs showed that Equipment Availability was 78.32%; Emergency Failure Intensity Ratio was 28.4%; Maintenance Cost Component was 32.39/btl; Cost of Maintenance hour was N125, 081/hr; Routine Service Worked was 92.03% and Cost of Reduction was 5.32hr/N. The overall maintenance productivity of the period under review was fairly good though there is room for improvement. Average overall maintenance productivity was found to be 63.2%. This is an indication that there were evaluations and review of maintenance productivity within the period.

Abstract: Productivity evaluation if based on historical record, and not the system’s potential, does not fully account for the maximum exploitation of the system. This work uses an optimization technique, the Linear Program, to establish the system’s potential; and then developed the Potential-based Productivity Evaluation model. Applying this model in an example problem gave productivity as 0.98, price recovery 1.07 and profitability 1.06; while the historical approach gave 2.81, 0.34 and 0.97 respectively. A comparison show 187% over-reporting, 65% under-reporting and 8% lag respectively. These would affect the firm’s decisions differently. The model can be used for strategic planning.