14 research outputs found
Abubakar Dauda. — “They love us because we give them Zakāt.” The Distribution of Wealth and the Making of Social Relations in Northern Nigeria
No full textThis book is based on a dissertation submitted in partial fulfillment of the requirements for the Ph.D at the Graduate School “Muslim Cultures and Societies” of the Freie Universität of Berlin. It is published as the twenty-third volume of the “Islam in Africa” series inititated by E. J. Brill in 2003. It is a good addition to this series, which had already made a considerable contribution to the understanding of Islam and Muslim societies in Africa. Its author, Dauda Abubakar, analyzes the p..
Evaluation of the Composition and Chemistry of Ash and Potash from Various Plant Materials-A Review
No full textFinite element modelling of hot rolling of Al-3%Mg and the kinetics of static recrystallisation
No full textThe principal objectives of this work were (i) to investigate the effect of geometry on the through-thickness gradient in microstructure evolved during post-deformation annealing treatment of rolled AI-3%Mg slabs and (ii) to employ the finite element method and empirical equations characterising the rate of static recrystallisation to predict the gradient in the volume fraction recrystallised through the slab thickness. Geometry was characterised by the aspect ratio of the deformation zone. The finite element method was used principally to simulate the evolution and spatial distribution of process parameters namely the strain, strain rate and temperature of deformation through the rolled slab thickness. Standard metallographic techniques and quantitative metallography combined with optical microscopy under polarised light were employed to measure the volume fraction recrystallised. The geometric orientation of microbands developed due to hot deformation was also characterised. Rate-dependent, thermomechanical material constitutive data based on the hyperbolic sine and Voce type of flow stress/strain relationships were used as input in the two-dimensional finite element model together with a friction model based on the penalty method. Published empirical equations linking the rate of static recrystallisation and the process parameters were then employed to predict the measured volume recrystallised. Results indicated that gradients in microstructure occurred through the rolled slab thickness for all the slab/geometry and rolling conditions considered and that the orientation of microbands developed independent of the rolling reduction. The main conclusions drawn were that (i) geometry had a profound effect on the evolution of microstructure through the rolled slab thickness; (ii) the finite element method can be used as an effective tool in the prediction of through-thickness gradient in microstructure evolved in the post-deformation annealing treatment; and (iii) microband development was an important microstructural feature during hot rolling of AI-3%Mg, acting as potential nucleation sites for subsequent static microstructural transformation processes. (author)Available from British Library Document Supply Centre-DSC:DXN045785 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo
Insights on Phytomonas: A Bibliometric Analysis on Global Research Outputs Highlighting Research Gaps and Future Directions
No full textThe study aims to access the research output on Phytomonas from inception to 2023 using bibliometric science mapping and visualization tools. We analyzed the distribution of publications retrieved from the Scopus database, categorized topics, and tracked progress over time. Additionally, we examined country contributions and author collaboration (co-authorship), with particular emphasis on research topics and emerging research areas. We also highlighted the paucity of research from Australia, Africa, and Asia, where Phytomonas could be a major parasite affecting important crops
A short view on the stress corrosion cracking and the prospect of ecofriendly inhibitors
No full textMetallic materials will continue to have challenges related to fracture, transcrystalline,
and hydrogen embrittlement corrosion due to severe area of application that is
unavoidable. The study into the performance of metallic materials has shown that
corrosion mechanism through stress corrosion cracking often occurs vis-viz due to the
electrochemical and reduction reaction. The phase diagram is important to solve
problems related to hot corrosion, hydrogen embrittlement, intergranular corrosion,
and stresses corrosion cracking challenges. The need to look into the defining
mechanism from the researcher cannot be underestimated. These overviews provide
insight on related problem definition and formulation towards corrosion challenges and
possible assessment of the corrosion inhibitors
Activity and Selectivity in the Electrochemical Reduction of CO2 at CuSnx Electrocatalysts Using a Zero-Gap Membrane Electrode Assembly
No full textThis article was originally published in Journal of The Electrochemical Society. The version of record is available at: https://doi.org/10.1149/1945-7111/ad6fd7.
© 2024 The Author(s). Published on behalf of The Electrochemical Society by IOP Publishing Limited. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited. [DOI: 10.1149/1945-7111/ad6fd7]In this study Cu, Sn, and bimetallic CuSnx nanoparticles were synthesized and evaluated as electrocatalysts for CO2 reduction using zero gap membrane electrode assemblies. Results show bimetallic electrocatalysts with Sn contents above 10% yield formate as a primary product with Faradaic Efficiencies near 70% at 350 mA cm−2. Cu-Snx electrocatalysts with less than 10% Sn yield CO at current densities below 350 mA cm−2 and relatively lower cell potentials. When the low-Sn content bimetallic electrocatalysts were evaluated in alkaline anolytes at 350 mA cm−2, ethanol was recorded as the primary product (FE = 48.5% at Ecell ≥ 3.0 V). We propose enhanced C2 activity and selectivity originate from Cu dimers adjacent to Sn atoms for bimetallic electrocatalyst with low-Sn content. The C2 active sites are lost when the surface Sn content exceeds 25%–38%.This work was supported by the U.S. National Science Foundation under Award Number 2119435. A.L.O. acknowledges funding by the National Science Foundation under Award Number 1954611. Portions of this research were conducted with high performance computing resources provided by Louisiana State University (http://www.hpc.lsu.edu)
The emergence of ethnic militia movements in Nigeria's Niger Delta
No full textIncludes bibliographical references (leaves 102-105)
Влияние эпидемий на экономическое развитие и финансовые рынки: структурированный обзор
No full textThe article reviews publications on the impact of epidemics, including the coronavirus pandemic, on economic development. The author first explores the mechanisms of such influence, including both direct and indirect effects. He then treats the channels of influence for direct effects — through the factors of the Solow model of productivity and the volume of production, demand and consumption, the volume of savings and investment; for indirect effects — through the influence on investors and consumers sentiment through media news, Internet, social networks. Drawing on the works focused on the coronavirus pandemic impact on markets, mainly financial markets, the authors summarize and structure the types of models used as well as dependent and independent variables. The findings contribute to identifying the ways of minimizing the pandemic negative impact on economies in general and financial markets in particular.В статье проведен обзор публикаций, посвященных влиянию эпидемий, в том числе пандемии коронавируса, на экономическое развитие. Рассмотрены механизмы такого влияния, включающие в себя как прямой, так и косвенный эффекты. Проанализированы каналы влияния: для прямых эффектов — посредством факторов модели Солоу производительности и объема производства, спроса и потребления, объема накоплений и инвестиций; для косвенных эффектов — посредством влияния на настроение инвесторов и потребителей через новости, СМИ, интернет, социальные сети. Сделав акцент на работах, исследовавших влияние пандемии коронавируса на рынках, преимущественно финансовых, мы обобщили и структурировали типы применяемых моделей, зависимые и независимые переменные, полученные результаты. Полученные результаты способствуют нахождению путей минимизации отрицательных последствий пандемии для экономики стран в целом и финансовых рынков в частности
A New Form of Authoritarianism? Rethinking Military Politics in Post-1999 Nigeria
No full textDespite the vast research that has been done on the Nigerian military, virtually all of these studies have failed to critically examine the accepted role of the military in the democratising phase. This is important because the relationship between the political elite and the military in post-military authoritarian states guarantees either democratic consolidation, or its reversal. In Nigeria, despite an appearance of significant progress in subordinating the military institution to democratic civilian authority, the military remains a crucial political actor in the polity. It appears that the military has yet to accept the core democratic principles of civilian oversight of the institution. This thesis, therefore, explores whether a new form of military authoritarianism is emerging in Nigeria, with the aim of understanding Nigeria’s military behaviour in a transitional phase, from prolonged military authoritarianism to democratisation. To examine this military behaviour, Alfred Stepan’s concept of military prerogatives that was used to understand the military’s behaviour in a transitional phase in Latin America is applied to Nigeria.
A crucial understanding of authoritarianism in Nigeria is initially discussed in this study using mainly document analysis strategy to examine whether multi-ethnic states, such as Nigeria, tend to have authoritarian systems. Six hypotheses form the core analysis of this thesis: first, that the military has retained significant military prerogatives; second, that retired military officers are gaining influential political and economic positions; third, autonomous military involvement in human rights abuses since 1999; and fourth, that civilian government oversight remains weak, and facilitates military authoritarianism. These hypotheses are primarily analysed using the elite interview technique. During the first half of 2011, the author conducted field research where serving and retired military officers were interviewed. The fifth hypothesis is that the military has intervened in politics post-1999. The examination of this hypothesis relies primarily on key security-related media reports (mostly newspaper editorials) on the military after 1999. The examination of the final hypothesis, that increases in military expenditures might facilitate a new form of military authoritarianism, relies primarily on descriptive statistical analysis. In addition, this study collated relevant historical materials that relate to the military, utilising national archival collections.
The empirical findings of this research did not identify a new form of military authoritarianism in Nigeria. The study, however, argues that the unrestricted institutional framework accorded the military has contributed significantly to authoritarian practices in the post-military era in Nigeria. This study discovered that there were similarities between the Brazilian and Nigerian militaries in regard to their military spending during their period in power. Both countries had lower defence budgets. Just as in Brazil, it appears that part of the reason the Nigerian military decided to relinquish power in 1999 had to do with its desire to gain a higher budget, something that was precluded in a military government struggling to retain a sense of legitimacy. The military needed a higher budget to modernise and re-professionalise its institution after more than a decade in power. This feature, which the Nigerian military shares with the Brazilian military, appears to justify the application to Nigeria of Alfred Stepan’s concept of military prerogatives.
