Empirical Investigation Of The Laminar Thermal Entrance Region And Turbulent Flow Heat Transfer For Non-Newtonian Silica Nanofluid In Hexagonal Tubes

This research seeks to determine for the flow of stable dispersion of 9.58% silicon-oxide (SiO2) nanoparticles by volume in water through three hexagonal tubes of hydraulic diameters 1.67 mm, 2.42 mm and 3.26 mm, the pressure drops across the length of the tubes with and without the application of constant heat flux to the test section. Constant heat flux was applied on the wall of each test section (by electric resistance method). The operating temperature range of 15-63°C was maintained for the experiments. Data were analyzed using conventional hydrodynamic and thermal correlations. The test sections were selected and set up (or instrumented) in a manner enabling the measurements of lengthwise local surface temperatures of test sections and the drop in pressure of fluid flow across the axial length of the test sections. Viscosity and thermal conductivity measurements for the nanofluid of interest were acquired by Sharif (2015), and were used in this study. The 9.58% volume concentration SiO2-water nanofluid friction coefficients were found to follow the same trend obtained by classical correlations for Newtonian fluids. Results show no significant difference between the friction coefficients of nanofluid and water if the nanofluid is modeled as a power law fluid. The nanofluid, however, sustained laminar flow longer than water over the range of Reynolds number tested when no heat had been applied, the effect is even more pronounced for decreased hydraulic diameter of test section. For the thermally developing flow, convective heat transfer values for the nanofluid were significantly enhanced compared to water, nearing 20% in the laminar flow regime. The measured local Nusselt numbers for the nanofluid lie within ±30% of the Lienhard and Lienhard (2013) model for laminar thermally developing flow, and about 30% or less of the Gnielinski (1976) correlation for turbulent flow. Pressure drops for the nanofluid flows exceed those of water by over 100%

Globalisation and HR practices in Africa: When culture refuses to make way for so-called universalistic perspectives

The paper demonstrates and exemplifies how cultural paradigms and the political and socio-economic spheres and organisational life are intertwined in an African context. The paper examines how some factors that are embedded in the cultural and institutional framework in Sub-Saharan African organisations interact with global perspectives and the degree of resistance they present to changes in human resource management (HRM) processes. The paper considers aspects of the universalistic perspectives that have resonance for human resource practices in Africa. Furthermore, it evaluates the question of the tensions between the contributions derived from the indigenous and historical factors, and the inputs from external sources, to human resource management in Africa. rnThe research is based on a survey of 100 practicing African human resources professionals. The respondents were drawn from the major institutional actors in Nigeria. rnThe research found that, despite the impact of globalisation and the Westernisaion of training and development in Africa, HRM practices remain largely culture-bound. Many aspects of Sub-Saharan African cultures pervade organisational processes, e.g. collectivism and paternalism, that refuse to make way for change. However, the paper concludes that some of these temerarious cultural aspects that are often described as counter-productive in much of the literature, could actually be utilised for community and employee engagement. rnThe paper makes a significant contribution to the literature on HRM practices in Africa, an area under-researched. It provides an opportunity to African HR managers to be more pragmatic in identifying the contextual issues and for beginning to identify aspects of African culture that could be value-adding in a fast changing management landscape. The paper demonstrates that HRM policies have specific cultural orientations and reflect on both the societal predispositions of the region; this exemplifies how cultural paradigms, the political sphere and organisational life are intertwined in an African context

Resisting global universalistic practices - the endurance of culture and particularism in African HRM

Purpose This article empirically assesses the extent to which factors rooted in the cultural and institutional framework in Sub-Saharan African organisational contexts challenge and resist the penetration of global practices and how these dynamics impact on human resource management (HRM). This article examines universalistic perspectives are significant for African HRM. The article discusses the tensions between the contributions derived from local and historical factors, and that of other environmental agents, to African HRM practice. Design/methodology The study is based on a survey among 100 practising African HRM executives representing significant organisations in Sub-Saharan Africa. Findings The main findings established that, in spite of Westernisation and globalising trends in learning and development in Africa, human resource practices are still profoundly embedded in the African cultural fabric. Significant elements of cultures in Sub-Saharan Africa pervade organisational processes; such aspects include collectivism and paternalism, which persistently resist change. The article, however, concludes that the resisting parts of Sub-Saharan African cultures which are viewed as counter-productive, can have positive resonance if constructively deployed. Originality This article contributes to African HRM literature, a significantly under-researched field. The paper provides an opportunity for African HR managers to be more pragmatic in identifying the contextual issues as well as aspects of African culture that could be value-adding in a fast-changing managerial field. The findings demonstrate that human resource strategies and policies have specific cultural orientations and reflect the societal predispositions of a particular collectivity; this epitomizes the intertwining of cultural paradigms, political spheres and organisational life in Sub-Saharan Afric

The Employment Situation of Migrant Workers and Their Experience of Work Life Pressures

The chapters in this book cover different aspects of the migrant experience of social life and employment in contemporary societ

Eradicating Poverty and Unemployment: Narratives of Survivalist Entrepreneurs

Researchers continue to argue that survivalist entrepreneurs remain the untapped source for improved socioeconomic development because they have the potential to create employment, and reduce poverty. Unemployment and poverty remain the biggest challenges for sub-Saharan Africa but specifically South Africa with an escalating unemployment rate. This is the basis for this study, which set out to provide an authentic insight into the lives of survivalist entrepreneurs in Cape Town, South Africa, for the purpose of revealing the reasons why they are unable to significantly grow and add substantially to the economy. A qualitative approach by way of personal interviews was followed so as to gain an in-depth understanding of the participants' stories. The findings suggest that survivalist entrepreneurs are able to assist in the socioeconomic development of an economy if appropriate support is given to them by government or through some public-private growth initiatives. This study contributes to survivalist entrepreneurship literature by specifically illuminating why, according to Statistics South Africa, survivalist entrepreneurs do not seem to create more employment opportunities, improve the economy and alleviate poverty. In acknowledgment of some of the study's limitations, we consequently advise that further study in this area may consider a combination of methods as well as other locations

Heavy metal concentrations in Bottom Sediments of Ikpoba River, Edo State, Nigeria

The concentrations of Fe, Mn, Zn, Cu, Pb, Cr, Ni and V were investigated.Samples were collected fortnightly from five (5) stations for four months (July to September, 2009) using Ekman grab operated by hand in shallow water. Station 1 is upstream (Old capitol bridge) and stations 2, 3, 4 and 5 are downstream. The main concentrations (ppm) in stations 1, 2, 3, 4 and 5 are: 931, 117, 812, 679 and 619.7 (Fe); 12.11, 21.08, 9.58, 8.64 and 7.89 (Mn); 9.90, 12.5, 9.64, 7.07 and 6.62 (Zn); 7.88, 8.04, 5.81, 4.34 and 3.88 (Cu); 0.48, 0.61, 0.36, 0.26, and 0.28 (Pb); 0.19, 0.26, 0.13, 0.12 and 0.11 (Cr); 0.12, 0.16, 0.08, 0.08 and 0.08 (Cd); 0.13, 0.19, 0.13, 0.11 and 0.11 (Ni) and 0.10, 0.15, 0.10, 0.09 and 0.09 (V). Analysis of variance (ANOVA) showed that Fe (Stations 1 and 2), Cr (Stations 1 and 2) and Cd (Station 2) were significantly different (p<0.05) between stations. All parameters studied were below FEPA limits. The heavy metal concentrations in bottom sediments of Ikpoba River showed a seasonalpattern of variation. This investigation in comparison with earlier study based on data from Jimoh, 2006; show that Fe and Mn concentration increased overtime while Cd, Pb, and Cu did not

Strategic management accounting and performance implications: a literature review and research agenda

The important role that management accounting plays in driving organisational performance has been reiterated in the literature. In line with that importance, the call for more effort to enhance knowledge on strategic management accounting has increased over the years. Responding to that call, this study utilised a qualitative approach that involved a systematic review to synthesise existing literature towards understanding the strategic management accounting foundation, contingency factors, and organisational performance impact. Based on the evidence in reviewed literature, we flag key directions for advancing this theoretical premise towards providing further insights that would enable practitioners strategically align their strategic management accounting practices for optimal organisational performance. The limitations of this study have been acknowledged

The conceptualisation of Employee Voice in Permacrisis: A UK Perspective

Research on the topic of employment relations often adopts analytical frameworks related mainly to the concept of ‘voice’. While originally defined as the effort to effect change by Albert Hirschman, the meaning and conceptualisations of the term ‘voice’ have evolved over the years. Later writers such as Freeman and Medoff describe the concept from the point of view of union monopoly of representation, i.e., union articulation of workers’ concern. In this chapter, we present a synthesis and overview of some of the early conceptualisations of employee voice and unionism in the United Kingdom. Our goal extends beyond simply sketching or cataloguing the historical analysis around voice, to using this analysis as an instrument for understanding the current state and projecting into the future of employee voice and unionism in the United Kingdom. The chapter reveals that the concept of voice has been significantly reinvented by modern-day scholars. The chapter will heavily depend on a review of extant literature. It would, however, be impossible to synthesise the entire literature on voice in this short chapter. Hence, there will be a significant focus on the United Kingdom experience and authors, howbeit, other authors based elsewhere may be selectively included. The study concludes that though employee voice is relevant today, in most cases it only serves the interest of management and where this is not the case management hardly pays any attention to it. The study revealed further that during permacrisis, there is little or no attempt on the part of the management to attention to or implement the demand expressed in employee voice

Novel adamantane-chloroquinolin conjugates to overcome plasmodium falciparum chloroquine resistance

Magister Scientiae - MSc (Pharmaceutical Chemistry)Malaria poses devastating health and socioeconomic outcomes on global health especially among pregnant women and children below the age of 5 in endemic areas. This is exacerbated by Plasmodium falciparum resistance to available antimalarial drugs, especially chloroquine (CQ), which was the drug of choice for many years against the blood stage of malaria