1,547 research outputs found
MEANING AND RELEVANCE IN NIGERIAN TRADITIONAL ARCHITECTURE: THE DIALECTICS OF GROWTH AND CHANGE
Aside from the brief descriptions of some traditional dwelling types and settlements gleaned from the notes of early Europeans explorers and missionaries, few and scattered efforts exist to provide information on the African Traditional Architecture. The early assumption that the Africans lived in unstructured, isolated bush communities with little appreciation of the aesthetics in town design may have restricted enquiry into indigenous African Architecture. This lack in information would appear compounded as architectural history and the theory of Architecture have traditionally emphasized the study of monuments. The monumental work in Sir Bannister Fletcher's History of Architecture left out the rest of Africa after elaborating on the Architecture of Egypt which featured the pyramids and the temple
Attrition Resistant Fischer-Tropsch Catalysts Based on FCC Supports
Commercial spent fluid catalytic cracking (FCC) catalysts provided by Engelhard and Albemarle were used as supports for Fe-based catalysts with the goal of improving the attrition resistance of typical F-T catalysts. Catalysts with the Ruhrchemie composition (100 Fe/5 Cu/4.2 K/25 spent FCC on mass basis) were prepared by wet impregnation. XRD and XANES analysis showed the presence of Fe{sub 2}O{sub 3} in calcined catalysts. FeC{sub x} and Fe{sub 3}O{sub 4} were present in the activated catalysts. The metal composition of the catalysts was analyzed by ICP-MS. F-T activity of the catalysts activated in situ in CO at the same conditions as used prior to the attrition tests was measured using a fixed bed reactor at T = 573 K, P = 1.38 MPa and H{sub 2}:CO ratio of 0.67. Cu and K promoted Fe supported over Engelhard provided spent FCC catalyst shows relatively good attrition resistance (8.2 wt% fines lost), high CO conversion (81%) and C{sub 5}+ hydrocarbons selectivity (18.3%)
Graphene Foam Reinforced Shape Memory Polymer Epoxy Composites
Shape memory polymer (SMP) epoxy has received growing interest due to its facile processing, low density, and high recoverable strain. Despite these positive attributes, SMP epoxy has drawbacks such as slow recovery rate, and inferior mechanical properties. The slow recovery rate restricts the use of SMP epoxy as a functional structure.
The aim of the present work is to explore the capabilities of three-dimensional (3D) graphene foam (GrF) and graphene nanoplatelet (GNP) as reinforcements in SMP epoxy to overcome their slow recovery and improve the mechanical properties. GrF and GNP based SMP epoxy composites are fabricated by mold-casting approach and 3D printing techniques, respectively. They are investigated for their thermal, shape recovery, and mechanical behaviors. 0.13 wt.% GrF addition results in 19% increase in the glass transition temperature (Tg) of mold-cast SMP epoxy. GrF-based SMP epoxy composite displays thermal conductivity of 0.296 W mk-1 at 70oC, which is 57% greater than that of SMP epoxy. The addition of GrF results in excellent thermal and electrical conductivity of SMP epoxy by providing a continuous network of graphene for phonon and electron flow, respectively. Thus, thermal and electrical stimulation are employed to actuate shape recovery in GrF-reinforced SMP epoxy composite. Maximum shape recovery ratio is achieved for thermally actuated GrF-based SMP epoxy composite with a 23% improvement in the recovery rate. GrF addition transforms a non-electrically conductive SMP epoxy to an electrically conductive polymer. Moreover, 0.5 wt.% GrF integration enhances tensile strength and elastic modulus of SMP epoxy by 6% and 20%, respectively which is attributed to excellent stress transfer from matrix to GrF reinforcement. Damping behavior of of SMP epoxy -0.5 wt.% GrF is also improved by 180%, respectively.
SMP epoxy-GNP composite is successfully 3D printed using a slurry-based extrusion technique. 3D printed composites exhibit complete shape recovery. A mere 0.1 wt.% GNP addition resulted in enhanced tensile strength (30%) and elastic modulus (17%). Damping behavior of 3D printed of SMP epoxy-GNP composite is also improved by 50% (below its Tg) as compared to 3D printed SMP epoxy. This study demonstrates that graphene-based reinforcement endow SMP epoxy with multifunctional capabilities; thereby paving the way for a new generation of advanced shape memory polymer composite, finding potential applications in electro-mechanical systems, micro-robots and morphing wing of an aircraft
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A model of virtuous leadership in Africa: case study of a Nigerian firm
The nature and extent of Africa’s leadership challenge has been explored from multi-theoretical perspectives finding that amongst other issues, it is ethical in nature. This study therefore aimed to investigate and present a model of virtuous leadership within an indigenous African firm’s context drawing from the African virtue ethics of Afro-communitarianism. Using a qualitative case study design, it explored a model of virtuous leadership within a leading Nigerian pharmaceutical brand. Data was collected from multiple primary sources including semi-structured interviews and informal conversations as well as secondary sources. This study found a virtuous leadership model underpinned by four African primary virtues – Truthfulness, Courage, Humility and Humanity within a context of communitarianism. It also found that the nature and practice of these four virtues by the leaders within the context positively shaped employees’ moral characters through visible modeling but not without its flaws. It concluded that virtuous leadership models are essential within the African leadership context to rise above existing status quo to build communities of practices that are not business as usual but seeking the ultimate end of facilitating the flourishing of immediate and wider communities alike
Asset Assessment for Women: A Case Study of Imasayi Village in Ogun State, Nigeria & NGO Development: A Strategic Plan
This paper presents the findings of an asset assessment performed with women in a village southwest of Nigeria, Imasayi Ogun state. This paper not only describes the process and results of a qualitative study, but also presents the implementation plan for an NGO that will work with the women of Imasayi to implement community-wide development projects. The research upon which this paper is based used the framework of seven capital domains, which are then used in turn to structure findings, recommendations and NGO planning and analysis. For the purpose of this paper, the marketplace is identified as significant for Imasayi’s women and is discussed in detail in relation to two other asset types, roads and community connections. The paper concludes with an in depth discussion of the proposed plan for the NGO, including the strategic direction, asset assessment and stakeholder analysis of the research, value chain and governance of the NGO. The goal for the NGO is to create a path to work with marginalized women to identify assets and maximize their capital base
Performance Improvement of Wireless Network Based on Effective Data Transmission
A major requirement of any computer network is scalability. This can be as a result of increase in the number of users, upgrading due to technological advancement, additional services, or the need for performance improvement. This will inevitably require changing infrastructure, deploying new applications, and dealing with security which definitely touches both hardware and software, in the sense that, the complexities of the hardware, software and firmware increase with the attendant growth of the network and maintainability. However, for the network to remain reliable and efficient, it is necessary that, implementation and administration of it requires a means of monitoring both the model of the network structures and processes occurring in them. The efficiency and throughput of the network depend on improving the effectiveness of data transmission carried out by the network protocols. This paper discusses the use of a protocol to meet the technological challenge towards improving the performance and throughput of a wireless network based on effective data transmission
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