Development and Evaluation of Maize Husks (Asbestos-Free) Based Brake Pad

The development and evaluation of maize husks as asbestos-free friction material for the production of automotive brake pad was carried out in this work. Asbestos friction material that has been used for over 80 years was found to be carcinogenic in nature and has prompted several research efforts for its replacement from brake pads. Three sets of composite compositions were made using maize husks as filler material to impart friction properties with varied epoxy resin contents as the matrix that bonded the particles in the mix.  Brake pad specimens were made out of the composites and subjected to mechanical, physical and tribological analyses to ascertain their possible performance in service using standard test procedures, materials and equipment. The particulate size of the MH filler material was 300µm and epoxy resin was in slurry. The result showed that specimen composite 3 with 30% MH filler content having coefficient of friction, abrasion resistance, water absorption, oil absorption, density, hardness, tensile strength, compressive strength, and thermal conductivity of 0.37, 4.470E-6g/m, 0.725%, 0.660%, 0.852g/cm3, 99.34mPa, 14.407mPa, 6.779mPa and 0.330W/mk respectively was optimum in performance. It was observed that reducing the filler content increased hardness, wear rate, tensile strength, compressive strength and thermal conductivity of the composite brake pad, while density, coefficient of friction water and oil absorption got increased with increased MH filler content. The result when compared with those of conventional brake pad made of asbestos and other friction materials of past researches showed that MH particles are an effective replacement for asbestos in automotive brake pad manufacture. Unlike asbestos based brake pad, the composite brake pads are eco-friendly and do not have the health hazards like cancer aggravation, asbestosis, mesothelioma, lung and other ailments associated with use of asbestos bearing components. Keywords: Brake pad; asbestos; maize husks, tribological properties

Development of water hyacinth briquetting machine

Briquetting technology is one of the renewable sources of energy that was developed to address problems concerning global warming, energy catastrophe, as well as solid waste management. Nigeria has abundant supplies of biomass resources and unrestricted solid waste, whose potentials are yet to be fully tapped for energy generation. It is, therefore, necessary to convert these waste into a product that will provide alternative energy to the people rather than constituting environmental problems. The study was undertaken to develop of hyacinth briquette machine and examine the properties of fuel briquettes produced from a mixture of waste paper (WP) and water hyacinth plant (WHP) using corn and cassava starch as a binder. WP from the academic environment and WHP harvested from the surface of fresh waters were used. Briquette machine was designed using a screw type extruder to convert the processed WHP and WP into solid briquette for domestic consumption. Samples of WHP was harvested, ground, dried and mixed with WP. The mixture was poured into a hopper. The physical and combustion properties of the briquette were determined at varying WHP and WP-binder ratios of 100:10, 100:15, 100:25, 100:30 and 100:45, 100:55 using corn starch as the binding agent. It was discovered that the binder ratio 100:25 demonstrated the most affirmative value of biomass energy than others. It was also observed that the cooking time for the briquette produced using WHP and WP was 40min/kg with SFC of 0.4kg/kg. The designed machine has production efficiency of 84% and also produced smoke-free WH briquettes with high resistance to mechanical action, better handling and efficient fuel characteristics for household use

Comparative assessment of the performance of friction materials based on different agricultural wastes

The composition of friction materials is being revolutionised to exclude contentious components. This work comparatively used palm kernel shells, maize husks, cocoa bean shells and melon shells separately with seven other component materials to achieve novel friction materials. Friction and wear of the friction materials were measured using the test rig designed and constructed in-house for this research. Results showed that the maize husk-based friction material performed greatest in terms of thermal stability, wear, porosity and water absorption. Their thermal stability level indicates suitability for use in low-speed passenger cars and other allied braking applications. Using the selected agricultural residues in place of the contentious components in traditional friction materials would potentially solve health and environmental safety challenges

Mechanical Characterisation and Modelling of a Pulverised Palm Kernel Shell based Spur Gear

Advances in power transmission using spur gear technology in some specific mechanical devices required lightweight to strength ratio of the gear material. This study evaluated the mechanical properties of a particulate palm kernel shell reinforced polyester composite (PPKSRPC) for spur gear application. The PPKSRPC sample was prepared and examined experimentally to determine its mechanical properties such as tensile strength, modulus of elasticity and shear modulus. The experimental result for 5% weight fraction of PPKSRPC gave a tensile strength, modulus of elasticity and shear modulus of 90.3 MPa, 2.35 GPa and 0.89 GPa, respectively. The value obtained was used to model the PPKSRPC spur gear under a torque of 140 N-m in ANSYS environment. The observed values of the responses (mechanical properties) of the PPKSRPC under loading conditions are lower compared to the conventional steel in spur gear application

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

The effect of an educational intervention programme on reproductive health: decision-making among couples in south west Nigeria

Context: Decision making process in reproductive health in Sub-Saharan Africa is a complex activity dictated by the customs, religious beliefs, socio-economic factors, and cultural innovations. The central role played by men in this process gives a strong justification for health education intervention with a primary focus on men. Objective: To find out how educational intervention programme will influence reproductive health decision making among couples. Study Design: This is a quasi-experimental study among couples in 3 towns in Osun State (Ode-Omu, Ejigbo and Otan-Ayegbaju) of Nigeria. Ode-Omu and Ejigbo served as the intervention towns while Otan-Ayegbaju served as the control. The study had 3 phases: baseline survey lasting 3 months, intervention phase of 12 months and postintervention period of 3 months. Interventions: Imparting information and educating members of the community on issues related to reproductive health with emphasis on the role of men using posters, handbills, public lectures, workshops and films. Main Outcome Measures: Decision making on and timing of pregnancy, seeking of post-abortion care, and husbands' support of wives during pregnancy. Results: After the intervention, more couples took joint decisions on timing of pregnancies; more husbands supported their wives during pregnancy and seeking of post-abortion care increased significantly in the intervention towns. Conclusion: Enlightenment of men is a faster and effective short-term measure to improve women's utilization of reproductive health resources. Keywords: men's role, reproductive health, decision-making Tropical Journal of Obstetrics and Gynaecology Vol. 22(1) 2005: 4-