The development of a novel method for arresting tunnel explosions

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University, 09/12/1998.The onset of an explosion in an underground mining environment is a threat that has over years attracted a lot of attention. Much of this attention has focused on either arresting the explosion after it has been initiated or preventing the initiation. The methods devised have proved successful in most cases, but on the odd occasion that they fail, the end results can be disastrous. There have been fatalities from underground mining explosions as a result of fires burning and sapping all the oxygen in the atmosphere leading to asphyxiation. A different approach to arresting these explosions would enhance safety in the face of increased productivity. A novel method using an explosion door with a porous media acting as a shock wave attenuator and arresting the flames has been introduced. This research investigates the ability of the porous media used in the explosion door to withstand explosions. The performance of the porous media is crucial, as its failure would render the explosion door useless. In order to assess the performance of the porous media, a shock tube was built capable of generating shock waves with a Mach number of 1.5. By placing samples of the porous media within the test section of the shock tube, pressure measurements were taken fore and aft of the porous media as it was impinged upon by the shock wave. Tests were also conducted using thin orifice plates to provide data for comparing the performance characteristics of the porous media. Computational fluid dynamics (CFD) simulations of the porous media and the orifice plates were performed to validate the experimental work as well providing graphic detail of the flow around the test specimen. The work presented in this thesis makes a contribution to the efforts towards the provision of a safe underground environment. This contribution is achieved by investigating the performance of the porous media to be used in an explosion door and correlating the performance of the porous media with thin orifice plates. The porous media in the work presented here is currently used in the castings industry and its application as a shock wave attenuator and fire arrester would contribute greatly to the well being of all people working underground

Social Studies/History Curricula in Ghana

Abstract This research will examine how social studies developed within the curricula within Ghana. I will report this in USA and juxtapose with Ghana and other post-colonial African countries. The study assesses the quantity of the content of history as it is merged with social studies curricula, its implications on students, economy, and educational sectors in Ghana. It is noted that majority of students at tertiary levels in Ghana would find it difficult to give detail information about Ghana’s history and Ghana’s historical place in the world when probed. Six post-colonial African countries’ social studies/history curricula are examined on the content and pedagogy employed in teaching, which is a reflection of that of Ghana, as only Nigeria from the six African countries, has re-introduced history as a core subject in the primary and secondary schools. Ghana’s curricula is contextualized with U.S curricula, as U.S has moved into closer cadence with the world in terms of balancing content instruction with the nurturing of historical thinking and historical consciousness. The foundations of social studies originated in Great Britain during the 1820s and quickly moved to United States. Social studies evolved during the era under examination to include history and the social sciences, and a more integrated, relevant approach to teaching those subjects. In post-colonial African countries, it was introduced by the British and subjects taught in schools reflected the taste of the colonial education officials, and school curricula were built around the existing colonial values.https://thekeep.eiu.edu/lib_awards_2018_docs/1001/thumbnail.jp

Social studies in non-western contexts: The development, appraisal, and implications of Ghana\u27s social studies curricula

Analyzing the position and rigor of Ghana\u27s history in the social studies curricula is essential in ascertaining robustness in fostering historical thinking and yielding a possible restructuring of the curricula to meet students’ social, academic, and global needs. The social studies taught at the middle and high schools in Ghana incorporate a superficial historical account of Ghana, eroding Ghana’s history in the curricula without careful consideration. This paper examined the quantity and quality of Ghana’s historical contents in the middle and high schools’ social studies curricula. Primary data collection was in-depth semi-structured interviews. Document analyses of syllabus, textbooks, and trade books served as a complementary data collection and yielded significant results. I purposefully sampled nineteen (19) social studies teachers from 18 middle and high schools in one district. The findings include a minimal concentration of historical facts in the curricula. The content and scaffolds promote minimal historical thinking. The resultant implications include misconceptions students and parents have about social studies and a dearth of historical content in the curricula. This paper contributes to the longstanding advocacy to restructure the social studies curricula to meet the academic needs of students considering the global trends in education

Service-Learning during the Covid Era: A Perspective of GK-12 Student-Coordinator

Despite the importance of service learning, the precariousness of the COVID-19 pandemic posed a challenge for students and educators. In this paper, I highlight the COVID-19 pandemic ramifications on the Graduate Students Engagement in K-12 Classrooms (GK-12) program, the lessons learned from going remote, and how we can be flexible with remote learning in the future if there is a need for us to adapt our programming to other crises

Social Studies/History Curricula in Ghana

Abstract This research will examine how social studies developed within the curricula within Ghana. I will report this in USA and juxtapose with Ghana and other post-colonial African countries. The study assesses the quantity of the content of history as it is merged with social studies curricula, its implications on students, economy, and educational sectors in Ghana. It is noted that majority of students at tertiary levels in Ghana would find it difficult to give detail information about Ghana’s history and Ghana’s historical place in the world when probed. Six post-colonial African countries’ social studies/history curricula are examined on the content and pedagogy employed in teaching, which is a reflection of that of Ghana, as only Nigeria from the six African countries, has re-introduced history as a core subject in the primary and secondary schools. Ghana’s curricula is contextualized with U.S curricula, as U.S has moved into closer cadence with the world in terms of balancing content instruction with the nurturing of historical thinking and historical consciousness. The foundations of social studies originated in Great Britain during the 1820s and quickly moved to United States. Social studies evolved during the era under examination to include history and the social sciences, and a more integrated, relevant approach to teaching those subjects. In post-colonial African countries, it was introduced by the British and subjects taught in schools reflected the taste of the colonial education officials, and school curricula were built around the existing colonial values.https://thekeep.eiu.edu/lib_awards_2018_docs/1001/thumbnail.jp

Fostering an Interactive Social Studies Classroom Instruction During a Pandemic: Experience, Practice, and Advice.

This essay expatiates and expounds on the merits and the demerits of two social studies instructional strategies (peer or collaborative learning and discussions) through virtual means in the current Covid-19 global pandemic, and offers eight helpful guidelines in addressing the demerits, for social studies instructors. The merits of virtual collaborative learning and discussions include distance learning, elicitation and extraction, introduction to new virtual technological tools, appreciation of diversity and diverse opinions, and sharing of external resources. The demerits include the fear of large class size, the disconnect in classroom interactions, cultural and socio-cultural differentiations, non-constructive discourses, the preferential syndrome, classroom discussion tardiness, and verbose posts. Eight recommendations are made for instructors which include the use of Voice Threads for audio and video discussions, a synchronous class introduction, responding to peers with minimal or no responses to their posts, assigning chapters of reading to students to present, balancing complimentary remarks with analytical critiques to posts, instructors to work with students to plan alternatives during technological challenges, and a formative and summative assessment of students’ engagement, discussion, and learning experiences

Sources Of Growth And Change In The Economy Of Ghana, 1900-1965

The primary objective of this study has been to quantitatively reconstruct a picture of the economic history of Ghana by putting together a set of macroeconomic data to cover the first six and a half decades of the twentieth century and using the data to analyze the sources of economic growth and structural change experience of the economy.;The analysis of the macro-experience of Ghana has shown the almost tripling in real terms in GDP per capita and the change of the economy from a virtual subsistence one around 1900 to an open, growth-oriented system by 1960. Recent experience in Ghana has, however, shown that the apparent attempts at take-off were not successful and that the growth process started in the first sixty years could not be sustained. The economy has either stagnated or declined since the mid-1960s and continues to decline. What explains the remarkable growth and structural change in the first half of the century and the reversal of the process thereafter? The approach used in this work to try to answer the above question is to exploit a simple general equilibrium model to decompose, quantitatively, the sources of growth and change.;The main findings of the study are that the structure of the economy changed very little between 1901 and 1950, but rapid changes in structure seem to have taken place after 1955. Secondly, the study shows that changes in the principal factors of production in Ghana (labour, agricultural capital and industrial capital) do provide a reasonable explanation for changes in income and export growth in the earlier decades but that during the last decade and a half of our study, the high levels of capital formation in the modern, industrial sector did not generate the wished for growth or structural transformation of the economy. Finally, contrary to conventional accounts of Ghana\u27s history, the study found changes in technology (or, more generally, changes in the efficiency of input use) and exogenous shifts in demand for exports to have been important in explaining growth and structural change. . . . (Author\u27s abstract exceeds stipulated maximum length. Discontinued here with permission of author.) UM

The role of beta-cell glutamate receptors in pancreatic endocrine function and in the pathogenesis of type 1 diabetes mellitus

Background: Kainate receptors (KARs) are one of the three classes of ionotropic glutamate receptors (iGluRs) expressed primarily in the central nervous system (CNS) where they mediate information transfer and neurotransmitter release. Very little is known about native KARs and their interacting partners outside the CNS. Aim: The aim of this study was to investigate systematically the molecular composition and functional properties of KARs in pancreatic endocrine cells and also to investigate the role of KARs in the pathogenesis of T1DM.Methods: The presence of KAR subunits was investigated in pancreatic clonal β-cells (MIN6 and INS-1), α-cells (α-TC) and primary rat islets of Langerhans using RT-PCR and immunoblotting. The effect of KAR activation on intracellular calcium concentration and insulin secretion in MIN6 was investigated using FURA-2AM epifluorescence imaging and Mercodia insulin assay respectively. The effect of glutamate, kainate and glutamate transporter inhibitor (dihydrokainic acid) on survival and viability of INS1, α-TC and neuroblastoma cells (SH-SY5Y) were investigated using MTT cell viability assay. The presence of autoantibodies against GluR subunits in serum of T1DM patients and controls was investigated using ELISA and immunoblotting. Results: RT-PCR identified mRNAs for GluK2-5 KAR subunits in clonal β-and α-cells and all five subunits (GluK1-5) in primary rat islets of Langerhans. The presence of these subunits was confirmed using immunoblotting with GluK2/3 and GluK5 antibodies. In addition, auxiliary KAR subunits Neto 1 and Neto 2 were also identified in all cell types. FURA-2AM epifluorescence imaging of cultured MIN6 β-cells showed that activation of KARs with kainate induced significant increase in intracellular calcium concentration and insulin secretion. These effects of kainate were blocked by KAR antagonist (NBQX; 30μM) but not by an antagonist (GYKI-53655 hydrochloride; 100μM) of other iGluRs. Chronic exposure to kainate (0.1-0.5mM), glutamate (0.25-12mM) and dihydrokainic acid (0.1mM) cause significantly reduced viability of pancreatic endocrine and neuronal cells. ELISA and immunoblotting showed that serum of T1DM patients and non-diabetic controls react against components of synaptosomal plasma membrane and also against overexpressed GluR subunits. Conclusion: Together, these results indicate that a range of functional KAR subunits and their interacting proteins are expressed in the endocrine pancreas. These KAR subunits identified could assemble as homomeric or heteromeric channels in both β-and α-cells of the pancreas. The activation of these receptors is likely to have an impact on pancreatic hormone secretion and viability of endocrine cells in the islets of Langerhans. Much work ought to be carried out to optimise the methods for identification of autoantibodies against GluR subunits in serum of T1DM patients. This will help to understand the potential role of GluRs in the pathogenesis of T1DM

The Relationship between Employee Voice and Organizational Performance at Electricity Company of Ghana

The old adage two heads are better than one suggests that organizations benefit from enriched decision making through employee participation more than imposing those decisions on the employees.  The research examined how employee voice contributes to the performance of companies using Electricity Company of Ghana as a case study.    A scatter diagram drawn showed that there is a relationship between employee voice and organizational performance.  The use of Pearson correlation to test the strength of the relationship proved that there is a strong relationship between the two set of variables.  The analysis showed that employees participation contribute about 95.2% of the total performance of Electricity Company of Ghana whilst 4.98% may  be attributed to other factors such as high wages and salaries or customer service.  Interviews conducted with the employees (98.5%) also indicated employees’ participation play a strong role in motivating employees of the company to work hard to improve the overall performance of the company.  It concluded by strongly recommending employees’ participation in decision making if organization want to improve upon their performance. Keywords: Employees voice, performance, Electricity Company of Ghana, motivatio

Vulnerability of Protected Areas to Human Encroachment, Climate Change and Fire in the Fragmented Tropical Forests of West Africa

The Upper Guinean region of West Africa is home to some of the most globally significant tropical biodiversity hotspots, providing ecosystem services that are crucial for the region’s socio-economic and environmental wellbeing. Nonetheless, following decades of human-caused destruction of natural habitats, protected areas currently remain the only significant refugia of original vegetation relics in landscapes that are highly fragmented. Aside from having strong geographic variation in land use, climate, vegetation, and human population, the region has also experienced remarkable biophysical and socio-economic changes in recent decades. All these factors influence the fire regime and the vulnerability of forests within protected areas to fire-mediated changes and forest loss, yet little is known about fire regimes and fire-vegetation interactions within the region. Therefore, the overarching goal of this dissertation was to improve our understanding of the interactions of climate, land use, and fire regimes, as well as effects of fire on forest resilience in the Upper Guinean region of West Africa. I conducted the first comprehensive regional analysis of the fire regime across the gradient from humid tropical forests to drier woodlands and woody savanna. This analysis revealed that different components of the fire regime were influenced by different environmental drivers. As a result, the various combinations of these environmental factors create distinctive fire regimes throughout the region. The results further showed increasing active fire trends in parts of the forested areas, and decreasing trend in fire activity across much of the savannas that were likely linked with land cover changes. An analysis of fire-vegetation interactions in the forest zone of Ghana provided evidence of alternative stable states involving tropical forest and a novel non-forest vegetation community maintained by fire-vegetation feedbacks. Furthermore, an analysis exploring recent drought-associated wildfires in the forest zone of Ghana revealed widespread fire encroachment into hitherto fire-resistant moist tropical forests, which were associated with forest degradation. These findings suggest that ongoing regional landscape and socio-economic changes along with climate change will lead to further changes in the fire regimes and forest vegetation of West Africa. Hence, efforts to project future fire regimes and develop regional strategies for adaptation will require an integrated approach, which encompasses multiple components of the fire regime and consider multiple drivers, including land use and climate. Furthermore, projections of future vegetation dynamics in the region will need to consider land use, vegetation, fires, and their dynamic landscape-scale interactions in the context of broader responses to climate change and human population growth. Overall, this dissertation produced novel results about the pathways and drivers of disturbance land cover change that are necessary for improving our understanding of ongoing changes in a lesser-known part of the tropics. These findings are also relevant for predicting and mitigating similar fire impacts in tropical forests worldwide