Multiple influences on corporate governance in sub-Saharan Africa : actors, strategies and implications

This paper examines the influences of three major actors – the international organisations, rating agencies, and indigenous African institutions - on the fledging corporate governance and accountability practice in Nigeria. Findings from this study suggest that corporate governance in Nigeria seems to be in a flux resulting from a degree of ‘confusion’ in the country’s corporate governance system with regards to ‘which corporate governance model’ to follow, due to the influential powers of these three actors, pulling the governance phenomenon in somewhat different directions. As a result, this paper adds to the debate on the diffusion and translation of governance practices across different institutional contexts, particularly drawing out inferences for the literature on the convergence of national systems of corporate governance

A Protoype System for Transmitting Power through Radio Frequency Signal for Powering Handheld Devices

Miniature devices development has been greatly complementing the technology developmental trend in telecommunication. This makes the new communication technology to sail smoothly into the society and creating unexpected market for both the telecommunication providers and embedded system manufactures. However power has been the major problem in the usage of some of these devices most especially in third world countries where power is epileptically supplied. This paper proposes a prototype system which wirelessly generates DC for charging and powering power-critical handheld and remotely located devices. The design captures 900MHz radio frequency signal with a dipole antenna, which is converted into DC and stores the power in the device’s battery or use it to power it. The major aim of this paper is to provide a prototypical system which provides a cheap, constant and environmental friendly system for powering and charging power critical handheld and remote devices thereby prevents systems failure due to power loss.DOI:http://dx.doi.org/10.11591/ijece.v2i4.57

Effect of Processing Parameters on the Density and Microstructure of Direct Laser Sintered Al-12Si Powders

The effect of processing parameters on the sintering behaviour of gas atomised Al-12Si powders has been investigated. Laser power, scanning rate, scan spacing and layer thickness are found to control the densification and the resultant microstructural characteristics of the laser sintered parts. It was found that sintered density increased as the energy density increased reaching a maximum of 80.2% at an energy input per unit volume of 67 J mm-3. For parts produced with a slightly lower power density (50 J mm-3), the microstructure consisted of fine dendrites with interconnected porosity while parts fabricated with a slightly higher power density (100 J mm-3) were noted to have a preponderance of coarse dendrites with a discontinuous network of irregular shaped pores surrounded by a fully dense aluminium-silicon matrix.Mechanical Engineerin

The Effect of Self-Regulated Learning Prompts on Learners' Performance in a Simulation Learning Environment

In this study, the effect of self-regulated learning (SRL) prompts on the academic performance of 30 key stage 3 science students learning with a computer-based simulation environment has been explored. Students were randomly assigned to either self-regulate learning (SRL) prompted or non-self-regulated learning (non-SRL) prompted condition. Mixed methods including pre and post self-regulatory skills questionnaires (SRSQ), pre and post reaction rates knowledge tests (RRKT), students’ activity sheets (SAS) and class-room observation were employed for data collection and analysis. Students in the SRL prompted group were given activity sheets which contained self-regulated learning prompts whereas students in the non-SRL prompted group received no SRL-prompts in their activity sheets. It was discovered that the incorporation of SRL prompted instructions into a computer-based simulation environment that teaches the rates of chemical reactions facilitated shift in learners’ academic performance more significantly than did the non-SRL-prompted condition. Data analysis indicated that this was associated with the presence of the SRL behavioural prompts in the activity sheets. The introduction of SRL-prompted instructions into a computer-based simulation learning environment assisted students to know what to do at the appropriate time during the given task. For science educational designers, this study establishes the platform to understand the application of SRL-prompted instructions to the teaching of different topics in a computer-based learning environment with a view to improving students’ academic performance

Co- and self-regulation in a computer supported collaborative learning environment among Key Stage Three students

The current understanding of students' co- and self-regulated learning behaviours during group learning is limited. Research on social cognitive models of self-regulated learning (SRL) focused primarily on understanding the processes that students use to self-regulate their learning and the subsequent benefits of SRL on learning and academic performance. Recently, sociocultural models have begun to argue that SRL is fostered, developed, and maintained within social contexts and as a result of interactions with teachers and peers. This research employs both social cognitive and sociocultural theories to investigate students' co- regulatory behaviours in a computer supported collaborative learning (CSCL) environment. The students worked in a computer based science simulation learning environment in which either self-regulatory prompts or co- and self- regulatory prompts were given. A longitudinal design methodology incorporating four studies was adopted. The first study engaged two hundred and fourteen year 7 and 8 (11-13 year oIds) students to pilot the developed co-regulated strategies for learning questionnaire (CRSLQ) in a high school at Bedfordshire County in the United Kingdom. The remaining three studies engaged forty year 7 students (11-12 year olds) from the same school who were randomly assigned to either the experimental or the control group to work collaboratively on various science topics. Both quantitative and qualitative data analyses were used to examine the strategies that students used to co- regulate their learning processes over time. Results from the quantitative analysis revealed a statistically significant difference between the experimental and the control groups in the students' demonstration of co-regulated learning (CRL) behaviours over time. However, the results from the knowledge tests, although they suggested that learning had taken place, did not reach statistical significance. Findings from the qualitative analysis suggested between group and within group differences in the nature of co-regulatory processes that groups used to co-regulate their learning behaviour over the course of the three studies. Theoretically, this research extends individual models of SRL to include social forms of regulation arguing that students acquire, refine, and use different forms of regulatory processes to regulate their learning behaviours during collaborative learning. Finally, given the emphasis on SRL throughout the national curriculum this research supports the use of collaborative tasks in a technology-rich learning environment as an instructional method to increase students' regulatory processes. Some recommendations for future work are then made

Equipment for application of postemergence directed sprays for weed control in narrow-row no-tillage soybeans

A field study was conducted in 1983 at The University of Tennessee Milan Experiment Station to assess the potential for using tractor-mounted postemergence directed spraying equipment for weed control in no-tillage soybeans (Glycine max) planted with 20-inch row spacing in wheat (Triticum aestivum) stubble. Six commercial or experimental directed sprayers either designed exclusively for or adapted to use in 20-inch rows were used to apply a tank mix of linuron and 2,4-DB in 12-inch soybeans. Crop injury due to both mechanical damage and chemical contact were subjectively assessed for each system. Sprayers producing the most injury (up to 40 percent) had some misaligned machine assemblies or had limited capability for adjustment of row protection shielding. Two shielded sprayers resulted in crop injury ratings of 10 percent or less. A single herbicide application with any of the sprayers gave good control (80 to 88 percent) of cocklebur (Xanthium pensylvanicum) with no significant differences among applicators. Control of large crabgrass (Digitaria sanguinalis) was poor (40 per cent) with all sprayers primarily because the grass was severely drought stressed at the time of application. Drought conditions during the growing season resulted in abnormally low yields. No significant differences in yields were shown among the treatments. However, yields in sprayed plots tended to be greater than those from untreated plots

Co- and self-regulation in a computer supported collaborative learning environment among Key Stage Three students

The current understanding of students' co- and self-regulated learning behaviours during group learning is limited. Research on social cognitive models of self-regulated learning (SRL) focused primarily on understanding the processes that students use to self-regulate their learning and the subsequent benefits of SRL on learning and academic performance. Recently, sociocultural models have begun to argue that SRL is fostered, developed, and maintained within social contexts and as a result of interactions with teachers and peers. This research employs both social cognitive and sociocultural theories to investigate students' co- regulatory behaviours in a computer supported collaborative learning (CSCL) environment. The students worked in a computer based science simulation learning environment in which either self-regulatory prompts or co- and self- regulatory prompts were given. A longitudinal design methodology incorporating four studies was adopted. The first study engaged two hundred and fourteen year 7 and 8 (11-13 year oIds) students to pilot the developed co-regulated strategies for learning questionnaire (CRSLQ) in a high school at Bedfordshire County in the United Kingdom. The remaining three studies engaged forty year 7 students (11-12 year olds) from the same school who were randomly assigned to either the experimental or the control group to work collaboratively on various science topics. Both quantitative and qualitative data analyses were used to examine the strategies that students used to co- regulate their learning processes over time. Results from the quantitative analysis revealed a statistically significant difference between the experimental and the control groups in the students' demonstration of co-regulated learning (CRL) behaviours over time. However, the results from the knowledge tests, although they suggested that learning had taken place, did not reach statistical significance. Findings from the qualitative analysis suggested between group and within group differences in the nature of co-regulatory processes that groups used to co-regulate their learning behaviour over the course of the three studies. Theoretically, this research extends individual models of SRL to include social forms of regulation arguing that students acquire, refine, and use different forms of regulatory processes to regulate their learning behaviours during collaborative learning. Finally, given the emphasis on SRL throughout the national curriculum this research supports the use of collaborative tasks in a technology-rich learning environment as an instructional method to increase students' regulatory processes. Some recommendations for future work are then made

Adapting Collaborative Learning Tools to Support Group Peer Mentorship

Group peer mentorship is a relatively new addition to the area of collaborative learning. We see an untapped potential in supporting this model of mentorship with the existing collaborative learning tools like peer review and wiki. Therefore, we proposed to use a modified peer review system and a modified wiki system. From our preliminary studies using both peer review and wiki systems, we found that participants preferred the peer-review system to the wiki system in supporting them for mentorship. Therefore, this dissertation specifically addresses how to adapt the peer review system to support group peer mentorship. We proposed a modified peer review system, which comprises seven stages – initial submission of the first draft of the paper by the author, the review of author’s paper by peer reviewers, release of review feedback to the author, back-evaluation of their reviews by the authors, modification of the paper by the author, submission of the final paper and the final stage where both authors and reviewers provide an evaluation of the peer review process with respect to their learning, their perception of the helpfulness of the process, and their satisfaction with the process. We also proposed to use our group matching algorithm, based on some constraints and the principles of the Hungarian algorithm, to achieve a diversified grouping of peers for each peer review session. With these, we conducted six peer review studies with the graduate and undergraduate students at the University of Saskatchewan and teachers in Chile. This dissertation reports on the findings from these studies. We found that peer review, with some modifications, is a good tool to facilitate group peer mentorship. An evaluation of the performance of our group matching algorithm showed an improvement over three other algorithms, with respect to three metrics – knowledge gain of peers, time and space consumption of the algorithm. Finally, this dissertation also shows that wiki has the potential to support group peer mentorship, but needs further research

A review on selective laser sintering/melting (SLS/SLM) of aluminium alloy powders: Processing, microstructure, and properties

Manufacturing businesses aiming to deliver their new customised products more quickly and gain more consumer markets for their products will increasingly employ selective laser sintering/melting (SLS/SLM) for fabricating high quality, low cost, repeatable, and reliable aluminium alloy powdered parts for automotive, aerospace, and aircraft applications. However, aluminium powder is known to be uniquely bedevilled with the tenacious surface oxide film which is difficult to avoid during SLS/SLM processing. The tenacity of the surface oxide film inhibits metallurgical bonding across the layers during SLS/SLM processing and this consequently leads to initiation of spheroidisation by Marangoni convection. Due to the paucity of publications on SLS/SLM processing of aluminium alloy powders, we review the current state of research and progress from different perspectives of the SLS/SLM, powder metallurgy (P/M) sintering, and pulsed electric current sintering (PECS) of ferrous, non-ferrous alloys, and composite powders as well as laser welding of aluminium alloys in order to provide a basis for follow-on-research that leads to the development of high productivity, SLS/SLM processing of aluminium alloy powders. Moreover, both P/M sintering and PECS of aluminium alloys are evaluated and related to the SLS process with a view to gaining useful insights especially in the aspects of liquid phase sintering (LPS) of aluminium alloys; application of LPS to SLS process; alloying effect in disrupting the surface oxide film of aluminium alloys; and designing of aluminium alloy suitable for the SLS/SLM process. Thereafter, SLS/SLM parameters, powder properties, and different types of lasers with their effects on the processing and densification of aluminium alloys are considered. The microstructure and metallurgical defects associated with SLS/SLM processed parts are also elucidated by highlighting the mechanism of their formation, the main influencing factors, and the remedial measures. Mechanical properties such as hardness, tensile, and fatigue strength of SLS/SLM processed parts are reported. The final part of this paper summarises findings from this review and outlines the trend for future research in the SLS/SLM processing of aluminium alloy powders

Wireless Sensor Networks (WSNs): Security and Privacy Issues and Solutions

Wireless sensor networks (WSNs) have become one of the current research areas, and it proves to be a very supportive technology for various applications such as environmental-, military-, health-, home-, and office-based applications. WSN can either be mobile wireless sensor network (MWSN) or static wireless sensor network (SWSN). MWSN is a specialized wireless network consisting of considerable number of mobile sensors, however the instability of its topology introduces several performance issues during data routing. SWSNs consisting of static nodes with static topology also share some of the security challenges of MWSNs due to some constraints associated with the sensor nodes. Security, privacy, computation and energy constraints, and reliability issues are the major challenges facing WSNs, especially during routing. To solve these challenges, WSN routing protocols must ensure confidentiality, integrity, privacy preservation, and reliability in the network. Thus, efficient and energy-aware countermeasures have to be designed to prevent intrusion in the network. In this chapter, we describe different forms of WSNs, challenges, solutions, and a point-to-point multi-hop-based secure solution for effective routing in WSNs