Coal fly ash and kaolin are ceramic compounds utilized as raw materials in the production of refractories. Fly ash is an environmental pollutant that emanates abundantly from coal thermal power plants. The management of the large amounts of fly ash produced has been very challenging, with serious economic and environmental consequences. Kaolin, on the other hand, is a natural and synthetic clay material used in medicines, paper, plastics, and cosmetic preparations. In this research, refractory materials (cordierite (Mg₂Al₄Si₅O₁₈), mullite (3Al₂O₃·2SiO₃), and kyanite (Al₂SiO₅)) were fabricated in four different experiments, and an assessment was made of the strength of each of the materials. Coal fly ash and kaolin were each blended with alumina as starting materials. MgO and AlF₃·3H₂O were each applied as additives to the reacting materials. The mixtures were molded and sintered at temperatures between 1000 °C and 1200 °C for three hours in a muffle furnace, and characterized by SEM and XRD. The analysis revealed the evolution of cordierite, mullite, and kyanite alongside other crystalline compounds. The formation of kyanite in experiment C, due to the addition of AlF₃·3H₂O, is unprecedented and phenomenal. The XRD figures show the corundum phases crystallize at 1100 °C in experiments A and B, and disappear at 1200 °C.

Refractories are non-metallic ceramic materials capable of withstanding temperatures higher than 1500 °C, where the refractoriness is defined by the pyrometric cone equivalent. Silica fume and fly ash are used in industries as cost-effective raw materials to fabricate refractory composites. Mullite ceramic (3Al2O3·2SiO2) is a widely used engineering ceramic material with high strength and high creep resistance at high temperatures, low thermal expansion coefficient, and thermal stability. Cordierite ceramics (Mg2Al4Si5O18) can be used as the carrier of environmental catalysts because of their low coefficient of thermal expansion and stable structure. Therefore, it is an important way to reduce the generation of waste pollutants (Silica fume, fly ash, etc.), reflecting the basic idea of the transformation of solid waste into valuable products. The components of refractory materials are discussed alongside their utilizations, properties, and characteristics.

Quality control in medical radiology is a process used by a regulatory authority to evaluate the performance of a diagnostic X-ray machine, including acceptable limits and the actions necessary to meet regulatory requirements. This study evaluates the radiation dose outputs of X-ray equipment in diagnostic medical hospitals by measuring mAs linearity, kVp accuracy, and reproducibility as quality control parameters to ensure that radiation doses administered to patients meet standard regulatory requirements. Radiation measuring instruments were used in this work to measure mAs, kVp accuracy, and reproducibility outputs for five (5) medical diagnostic X-ray machines. The detector was placed on the couch at a distance of 100 cm from the collimator to take measurements for each parameter under investigation. Dose rate measurements for each parameter were recorded one at a time. The mathematical equations for mAs linearity, kVp accuracy, and reproducibility were used to compute the linearity coefficient, percentage error, and coefficient of variation. The computed figures for mAs linearity for the five X-ray machines show that four (4) passed and one fell below the allowable limit. Data for kVp accuracy indicate that three of the machines are within the allowable limits and two (2) failed, while the calculated values for reproducibility show that only two (2) machines passed the tests. The study generates empirical quality control data rarely reported in X-ray diagnostic centers. It verifies the linearity coefficient, percentage kVp error, and the coefficient of variation with practical knowledge in radiology studies. Additionally, it provides a systematic mathematical approach to compute mAs linearity, kVp accuracy, and reproducibility for teaching radiology in non-diagnostic laboratory settings.