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Long term exposure to very high levels of radiations from medical diagnostic centres, industries, nuclear research establishments and nuclear weapon development have resulted in health effects such as cancer and acute radiation syndrome, hence the need for proper radiation shielding. This paper investigated Epoxy-Lead (II) Oxide (PbO) composite as radiation shielding. The composites were prepared by dispersion of microsized PbO particles into polymeric materials using effective melt-mixing method and cast in a 4 cm by 6 cm rectangular aluminium Mold with a thickness of 5 mm and was allowed to set over night at room temperature. The gamma ray attenuation ability of the composites were studied using gamma ray transmission or attenuation coefficient determination for the gamma ray energy. Three gamma ray sources Ba-133, Cs-137 and Co-60 were employed. The density, linear attenuation coefficient, half value layer (HVL), relaxation length and heaviness of the samples were determined. The measured values of linear attenuation coefficient increased with increasing filler concentration in all the samples at all gamma ray energies. It was also noticed that 40 % and 50 % filler samples attenuates more relative to the other samples under study. The maximum linear attenuation attained was found at energy of 662 keV. The composites have been found to possessed medical gamma-ray attenuation characteristics among the sample materials over a certain photon energy range (0.08 MeV–1.332 MeV) and found useful as a biological radiation shielding against gamma rays.

This study presents the appraisal of indentation hardness and flexural modulus of composites prepared by mixing particles of palm kernel shell (PKS), coconut shell (CNS) and mixtures of palm kernel-coconut shell (MPKCNS) of different sizes (35.5 µm, 75 µm and 106 µm) with epoxy and hardener for various applications. The Rockwell hardness tester results showed that PKS particles epoxy filled composites of 35.5 µm had the highest hardness number of 77 while the MPKCNS particles epoxy filled composites of 106 µm had the least hardness number of 43. The CNS particles epoxy filled composites of 35.5 µm and 75 µm had relatively higher flex moduli of 428.66 MPa and 425.55 MPa respectively. The particle size of 106 µm had relatively higher flexure extension than 35.5 µm and 75 µm. The Scanning Electron Microscope (SEM) analysis revealed proper adhesion of the shell particles and epoxy resins with little or no pores in the composites. The PKS particles epoxy filled composites of 35.5 µm can be employed to enhance the mechanical properties of the composites for engineering applications.

The suitability of fine and coarse Okelele clays as refractory raw materials for furnace lining application was investigated. The clay samples were crushed and pounded with a mortar and pestle to a particle size of 20 microns. 230 g each of fine clay was mixed with 50 mls of water inside a bowl and stirred thoroughly to form homogenous plastic paste. 10 g, 15 g, 25 g, 35 g and 45 g of coarse clay were added respectively to the 230 g of homogenous fine clay paste in different container. The fine and coarse clays composites weighing 240 g, 245 g, 255 g, 265 g and 275 g were respectively put in a mold of dimension 3 x 5 x 6 cm and air dried for 7 days. The samples were fired at temperature of 1200 oC for five hours using Carbolite Furnace. After cooling, the fine and coarse clay composites of 240 g and 245g were broken by the heat and composites blocks 255 g, 265g and 275g were hardened and remove for compressive test analysis. The fine and coarse clays were characterized using X-ray Diffractometer PW1830forminerals phases’ identification. The result of XRD shows that the clay was majorly composed of Quartz and Kaolinite with the traces of other minerals such as Smectile, Illite/Mica, Albite, Jarosite, Gypsum and Pyrite. The Kaolinite contains aluminum silicate (Al2O3·2SiO2) and Quartz has the silicon and oxygen atoms. The compressive strength test result judged the 275 g fire block of clays composite the best with the maximum force breaks of 7652 N with deflection of 3.734 mm and Young Modulus of 212 N/mm2 for the time to failure of 22 seconds. The results proved that Okelele clays are suitable as refractory material for furnace lining application.