Advanced Materials Research Vols. 18-19

Abstract: In this work, the influence of magnetic field on I-V characteristics of bifacial silicon solar cell n+-p-p+ structure is studied under constant multispectral illumination. After resolution of continuity equation related to photogenerated minority carriers’ density in the base region of this cell, MATLAB numerical simulations of excess minority carriers’, photocurrent densities and junction photovoltage profiles, have been developed with magnetic field in the bulk of the base region. In the same way, the IV characteristics have been studied with magnetic field. It has been demonstrated that the I–V characteristics decreased. It also has shown how the I–V characteristics changed.

Abstract: The achievement of energy efficiency in the building sub-sector is considered a very important issue in contemporary research and development efforts by engineers, architects and environmentalists. This is because of its direct impact on national economies and indirectly on the environment and the general well being of future generations. This paper attempts an evaluation of the potentials of passive design in the warm humid zone of Nigeria by assessing the level of energy conservation in building through solar orientation. Model experimental buildings were constructed and comfort factors (indoor and out door temperature, relative humidity, solar radiation, etc) measured, and the climatic and technical (construction) factors determined for each of the model buildings using known methods. Regression model on the effect of solar radiation on the climatic and technical factors reflecting the amount of heat energy required to achieve an acceptable comfort level for each building was formulated. Results from the study show that there is strong evidence of tremendous potentials in passive design as ecotechique for energy conservation in buildings.

Abstract: Solar energy is increasingly becoming a significant component in the energy profiles of several tropical nations. This paper discusses trends in solar tracking technologies: analyzing the cost of acquisition, domains of application, maintenance costs and efficiency improvements. The paper concludes that hydraulic-based tracking systems are suitable for low capacity installations with low pay loads while polar axis tracking systems offer a performance nearly equal to that of two-axis tracking systems, at the cost of single axis trackers.

Abstract: This paper focuses on the problem of scheduling n jobs with release dates on a single machine in order to minimize the total completion time. Since the problem has been characterized as strongly NP-hard, two heuristics (HR1 and AEO) were proposed for solving the problem in polynomial time. The heuristics were compared with the best approximation algorithm for this problem to date (Best-alpha). Experimental results show that AEO performed better than the Bestalpha algorithm (selected from the literature) when the number of jobs (n) exceeds 5. This observation should prove useful in the operational dispatch of jobs in industrial production settings as well as the service sector.

Abstract: A computerized approach as opposed to a manual approach provides a fast and easy way of generating various workplace layouts in situ and consequently, CADWORK, a computerized heuristic capable of constructing a workplace from scratch, evaluating and improving a workplace fed into it, has been applied in this paper to design a workplace for the assembly of a domestic fan. An assembly layout constructed and evaluated by CADWORK yielded a cycle time of 1758.99 TMU at 100 BS performance level. Further modification of the workplace to search for improvements yielded an assembly time of 1623.09 TMU for the domestic fan.

Abstract: Over more than two decades the authors and their research colleagues have investigated different ways of using enterprise, simulation and workflow modelling techniques to structure and support decision making during organisation design and change projects. This has involved collaborative research with large and small scale manufacturing enterprises [1]. The investigations have demonstrated and advanced the potential to use enterprise models that ‘externalise and share knowledge about enterprise processes and systems’. By so doing, enhanced understanding of enterprise structures, processes and resource systems can be obtained and used to improve the interactions between system components so as to realise desired business performance and constrain unwanted behaviours.

Abstract: The Niger Delta Region, although the back bone of Nigerian economy, has been neglected by successive governments over time. There are no good schools, no health facilities, no water and other facilities within this area. The problem of the area is compounded by lack of good transportation system. This has been a hindrance both for security agencies and the people in the restive area. A good transportation system should ensure that people, goods and services move speedily, conveniently, safely and cost effectively. To have an efficient ground and water transportation system needed in this area requires adequate and accurate Geo-spatial information. In this paper, the benefits of adequate transportation system in the Niger Delta Region are highlighted. The roles of Geo-spatial data and Geo-spatial information system in the planning, development and management of an efficient transportation system are discussed. The paper also examines Geospatial Data infrastructure (GDI) in the development of the Niger Delta transportation sector Master plan, with data generated for Edo and Delta States presenting case study scenarios.