The widespread occurrence and availability of coal makes it the world’s prime source of energy for different end use applications. Coal is commonly used for electricity production through coal combustion. However, many researchers have indicated that coal combustion is a prime contributor to emission of greenhouse gases contributing to global warming. During combustion gaseous elements such as sulfur, hydrogen, carbon and nitrogen react with oxygen to produce their respective oxides. These oxides contribute to global warming, air and water pollution as well as acid deposition. Emission of these oxides and their effect on the environment has resulted in increased interest in clean coal technologies. Clean coal technologies, such as coal gasification technology, use multiple technologies to control the emissions so as to minimize environmental effects from coal utilization.

In this paper, the characteristics of Morupule coal from the south and east main sections are determined to establish its suitability for gasification. The characterization was conducted using thermal analysis (Thermogravimetric Analyzer) and an X-Ray Fluorescence (XRF). Numerical simulation was also carried out using Ansys software for species transport. The samples proved the coal to be from a high ash and sulfur content and medium volatiles bituminous parent rock, whilst species transport revealed a sufficient syngas yield per kilogram of coal for downstream processes.

Copper Zinc Tin Sulphide (Cu2ZnSnS4) materials are of interest for Photovoltaic applications. In this work, i.e., the first phase of Cu2ZnSnS4 synthesis, Cu-Zn-Sn film precursors were synthesised using electron beam deposition. The crystal structure of the synthesised film precursors were characterised by X-ray Diffraction (XRD) and elemental composition identification performed using Rutherford Backscattering Spectrometry (RBS). The synthesis results obtained are in agreement with those presented in the literature indicating that the metallic CZT film precursors were successfully synthesised.

The material and absorptive properties of a commercial selective solar absorber were studied after being exposed to temperatures that could be expected during its lifespan in a solar collecting device. The samples were tested as both flat sheets, and after being rolled into the shape of a tube. Moreover, the morphological analysis of the annealed samples at 100, 200, 300, 400 and 500 °C revealed an increase in the crystallite size of the thin films with increasing annealing temperature, and larger agglomerates where observed for samples annealed at temperatures above 200 °C . The total diffuse reflectance of the annealed samples was performed and the obtained data was used to calculate their solar absorption at wavelengths ranging from 200 to 2600 nm. Interestingly, optical performance degradation was observed above 200 °C indicating that the structural changes of the thin films at higher temperature induced a reduction in the efficiency of the selective absorber coating. Additionally, no significant difference in the physical properties and rate of efficiency decline between the flat and the rolled sheets of the solar absorber coating was observed indicating its potential use as a cylindrical shaped absorber for concentrating solar power application.

Mesoporous silicas were synthesized via a surfactant-templated sol-gel route using castor oil as the templating agent under acidic medium. The resulting silicas were subsequently amine functionalized with 3-aminopropyltriethoxysilane (NH2-MTS), [3-(2-aminoethylamino)-propyl]trimethoxysilane (NN-MTS), and [3-(diethylamino)propyl]trimethoxysilane(DN-MTS) to introduce surface basicity. Surface physicochemical properties were characterized by field emission gun scanning electron microscopy (FEGSEM), nitrogen porosimetry, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and diffuse reflectance infrared fourier transform spectroscopy (DRIFTS). As-synthesised materials exhibit type IV adsorption-desorption isotherms characteristic of mesoporous structures. Clusters of spherical shaped materials were observed by FEGSEM, suggesting growth of silica occurs within colloidal dispersions. High-resolution N 1s XP spectra and DRIFT spectra confirmed the presence of amine groups in the organo-amine functionalised mesoporous silicas. The amine functionalised mesoporous silicas were active for the transesterification of tributyrin with methanol, with conversion found to increase from NH2-MTS< NN-MTS< DN-MTS.

Ti-based quasicrystals are well known to store a high capacity of hydrogen exceeding the density of liquid hydrogen. This fact is due to that TiZrNi contain a large number of tetrahedral sites formed with Ti and Zr atoms that are chemical affinity with hydrogen. TiZrNi quasicrystal absorbs hydrogen up to host metal ratio (H/M) value near to 2.0. The disadvantage is due to the low equilibrium pressure. To solve this problem, we substituted Ti with a small amount of vanadium (V), with the nominal composition Ti45−x VxZr38Ni17 (x = 5, 10, 15) and synthesized by mechanical alloying. The subsequent annealing in vacuum conditions converted the amorphous into an icosahedral quasicrystal (I-phase) with face-centered cubic (FCC) Ti2Ni-type crystal. As the results, we investigated the discharge capacity for both amorphous and quasicrystal electrodes using three electrodes system (working, reference and counter electrodes) at room temperature. The highest discharge capacities obtained were 81.45 mAh/g recorded for amorphous electrode and 318.4 mAh/g for quasicrystal whose compositions is Ti35V10Zr38Ni17 at discharge current density of 15 mA/g. X-ray diffraction measurement was performed to provide the structural information on materials before and after hydrogenation. Microstructures of the materials were studied using an electron scanning microscope and the chemical compositions were confirmed using an EDX-analysis.

This paper investigates the role degradation of protective diffusion aluminide coating on Inconel 713LC used for CT blades of short-haul aircraft fleet played in having the blades prematurely retired from service at 6378 hours, as opposed to their pre-set service time of 10000 hours. The blade samples were subjected to various examinations; X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analyse at the; tips, airfoil, as well as the base, transverse and longitudinal, sectioned and unsectioned. As affirmed by both the transverse and longitudinal sections examinations, it was established that thermal attack leading to deterioration of the coating was greater at the tip and airfoils of the blades (the hotter zones) and lesser towards the bases (colder zones). As a result, severe degradation of the core material at the tips and airfoils compared to the bases and more prevalent at the leading edges than trailing edges at the tips. The results further suggest that both active outward Ni diffusion and inward Al diffusion can coexist during exploitation of the blades in service. The study illustrates the role played by the aluminide coating in early failure of CT blades with the aim of bettering the surface coatings and enhancing coating technologies, managing CT blade material monitoring as well as to give insights on advancing CT blades maintenance practices.