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In this paper, we present the results of finite element analysis (FEA) performed to investigate nature of stress and their distribution at optimum point along the two turning tables of a micro-controller based versatile machine tool desktop learning module. Commercial Autodesk Inventor was used to create both three-dimensional (3-D) and 2-D models as well as performing simulation. Dynamics simulation generated the motion load expected to act on the tables when used for real-life operation which were in turn used to perform FEA. The motion of the dc servo motor driving the tables and other parts of the module is designed to be controlled by programmable chips. Before creating FEA simulation for the tables, numerical divergence were prevented by varying the mesh settings to obtain the settings at which the results of the analyses converges which was obtained at 0.03 average element size and 0.04 minimum element size. Finite element analysis carried out on the tables shows that aluminium alloy 4032-T6 chosen will serve in the fabrication of physical prototype. FEA revealed the nature and level of stresses that will be experienced on the tables, it also revealed region where these stresses will concentrate on them. The analysis also estimated the expected weight of the turning tables 1&2 to be 1.23536 to 0.257182 Kg respectively and show that the minimum factor of safety was constantly 15 ul within the tables which shows that they will not fail during operation. [ABSTRACT FROM AUTHOR]

International field trips provide opportunities for interdisciplinary or transdisciplinary learning experiences which can be transformative. Whilst these projects are becoming popular with increasing focus on internationalisation of the curriculum, tackling global challenges and encouraging student mobility, there is scant literature on the critical pedagogical approaches which support the design and delivery of transformative learning experiences. The study described herewith examined the transformative pedagogies used to facilitate learning during interdisciplinary and transdisciplinary field trips and placements. Objectives of the study included (1) evaluating the impact of two projects related to student interdisciplinary and transdisciplinary field trips; (2) identifying best practice of teaching and learning design; and (3) providing recommendations for future higher education (HE) arrangements. The findings show that transformative learning experiences must be carefully integrated into the design of international field trips, setting up pivotal learning moments and suitable challenges which enhance reflexivity, shared learning and problem-solving. [ABSTRACT FROM AUTHOR]

In this study, a miniature fluidised bed boiler for steam generation was designed and constructed. The boiler is made up of a steam drum, combustion chamber, downcomer and riser tubes as a heat exchanger, a non-return valve and superheater tube. Experimental investigation on the fuel distribution was carried in two-dimensional chamber with crosssection of 500 mm x 1000 mm and bed height of 77 mm, 47 mm and 27 mm. The results obtained from the performance evaluation of the fluidised bed boiler operated with corncob at constant feed rate of 6kg/h for various bed heights of 77 mm, 47 mm and 27 mm recorded stability in the saturation temperature of 121 °C at 50 minutes, 144 °C at 45 minutes and 153 °C at 30 minutes, respectively. In additional, saturation pressures of 2.0 bar from 50 to 55 minutes for bed height of 77 mm, 2.1 bar from 45 to 50 minutes for bed height of 47 mm and 3.6 to 3.7 bar from 45 to 55 minutes for bed height 27 mm were obtained. The effect of fuel particle size on emissions and over all combustion efficiency of corncobs has proven to be efficient in a fluidised bed boiler as the emission analysis of the flue gas has shown to be low in various percentages of 0.0003% of NOx, 0.001% HC, 0.02% of CO and 0.93% of Nitrogenm, respectively. [ABSTRACT FROM AUTHOR]

Globalisation has brought a number of challenges to the fore, particularly those problems which require collaboration, innovation and capability development between nations. There are some complex issues piquing the attention of researchers with respect to sustainable development, such as, waste management, climate change, and access to amenities, housing or education. Non-Governmental Organisations, Institutions, governments and others working in the field of international development have been grappling with these difficulties for decades. However, it is becoming apparent that many of these difficulties require multifaceted solutions, particularly in Low and Middle Income countries (LMIC) where it is difficult to consolidate gains and fund schemes. Development work can sometimes be disjointed and inefficient, impairing the capability of local communities and inhibiting sustainable and innovative approaches. Transdisciplinary collaboration is reliably a more efficient way of tackling some of the most pertinacious challenges. This paper presents findings from a transdisciplinary research project focussed on developing resources and capacity for the construction of affordable homes in a low income community in Nigeria. The project explored the suitability of using upcycled materials such as plastic bottles and agricultural waste in construction. Using a user-centred, co-creation methodology, a team of experts from the UK and Nigeria worked with local entrepreneurs to build a prototype home. The study explores the functionality of the home and the sustainability of project. The findings demonstrate the benefits of tackling global challenges from a transdisciplinary perspective. This has implications for researchers focused on developing technical solutions for low-income communities. [ABSTRACT FROM AUTHOR]

The objective of this study was to prepare low-cost macroporous ceramic membranes using natural kaolin obtained from deposits in Nigeria and Ghana, and powdery high density polyethelene (PHDPE) as porogen agent. The ceramic membranes have been prepared with porogen content wt% between (0 and 20)% by die pressing. Pellets were fired at 1150 °C and soaking time of 4 h. The raw materials were characterized using TG/DTA, particle size distribution (PSD) and Zeta potential. The membranes cast as circular disks were subjected for characterization studies using XRD and SEM analysis. In a bid to correlate the physico-mechanical properties vis-à-vis pore former content, the effect of the sintering temperature and pore former (PHDPE) content on porosity, density, water absorption and mechanical strength were evaluated. The membrane corrosion resistance was found to be unaltered with experimental conditions. Obtained membranes showed good porosity with maximum at about 62% with a mechanical strength that does not exceed 18 MPa. These membranes can be considered as efficient regarding the results shown in the gas permeation tests at different sintering temperatures. A PHDPE percentage of 20% and a sintering temperature of 1150 °C were chosen as the optimum for gas permeation based on enlarged pore diameter of sintered membranes. [ABSTRACT FROM AUTHOR]

In this work, the suitability of using kaolin–styrofoam, sawdust, and high density polyethylene to produce porous ceramic bodies was experimentally investigated. The kaolin samples (raw and beneficiated) were characterized by the XRD, SEM, TGA/DSC and FTIR methods. Batch formulations of the samples including the kaolin and pore formers were formed into green bodies and fired to 1150 °C. The porosities of sintered bodies were calculated and gave the following: apparent porosity: 28.63%–67.13% for all the samples investigated. Samples with high density polyethylene (HDPE) pore formers showed minor surface cracks after firing, but exhibited the highest porosity levels while samples with styrofoam and saw dust exhibited uniform surface characteristics with pores, thermal stability and no visible surface cracks. It can be concluded that formulations containing 80% kaolin can be used for the production of ceramics with porosities as high as 67% if the right pore formers are used. [ABSTRACT FROM AUTHOR]

In this work, kaolin based ceramics using styrofoam, sawdust, and powdery high density polyethylene as pore formers were experimentally investigated. Prior to batch formulations, the kaolinite used was wet beneficiated. This was followed by mixing starting materials with pore formers, producing green bodies which were then uni-axially compacted into standard sample dimensions and fired at various sintering temperatures of 850°C, 1000°C and 1150°C for 2 hours in a furnace. The physical and mechanical properties of the sintered samples were investigated and the generated data analysed. It was observed that the apparent porosity and water absorption of the samples decreased with increased sintering temperature, while the bulk density, apparent density and cold crushing strength of the samples increased with increased sintering temperature. It was concluded that the samples which were sintered at 850°C with 5% wt pore former of powdery high density polyethylene gave the optimum properties in terms of the porosity and mechanical strength of the samples. [ABSTRACT FROM AUTHOR]

In this study, the crack behaviour of porous kaolin based ceramics was experimentally investigated. The samples (ceramic bodies) were fabricated with the inclusion of pore formers in determined proportions and subjected to heat treatment. Next, the apparent porosity of the samples was measured using the water immersion method. The values confirmed the increased porosity (up to 47%) for the samples with embedded pores. We speculated that the open pores on the surface of the samples which were quite evident, especially with styrofoam as pore formers, may also have penetrated through, hence the enhanced porosity values for the samples. Acoustic emission (AE) activity which reveals the formation of microcracks in the ceramics due to the different thermal expansion coefficients in the cooling stage was recorded for the samples. The first signals of AE counts appeared at 800 °C, where the compressive stresses between the different phases (particles with different coefficients of thermal expansion) led to an appearance of microcracks. By introducing porosity to the samples, the AE signals were less pronounced. This was evident for the samples with sawdust as pore formers, and it was inferred that in this sample, microcracking was suppressed. As a validation protocol for AE measurements, mechanical measurements on the produced samples were conducted through the indentation technique to obtain the fracture toughness of the samples. The results conformed to the observation made during AE measurements. The samples embedded with sawdust as porogens produced the highest fracture toughness of 4.77 MPa.m1/2 by reason of the suppression of microcracking after heat treatment. [ABSTRACT FROM AUTHOR]