The study evaluated the influence of Costus lateriflorus bagasse fibre on the properties of expansive soils. Laterite and clay soil samples along Ubeta-Ula-Ubie road in Ahoada West LGA of Rivers state, Nigeria were prepared and subjected to laboratory analysis for swelling potential, volume change, maximum dry density (MDD), optimum moisture content (OMC), consistency limits, California bearing ratio (CBR) and unconfined compressive strength (UCS). Preliminary analysis classified the soils as A-7- 6 on the AASHTO classification system. Swelling potential, volume change, maximum dry density (MDD), liquid limit (LL) and plasticity index (PI) of the stabilized Laterite and clay soils along Ubeta-Ula-Ubie road decreased with increasing percentage of Costus lateriflorus bagasse fibre, while optimum moisture content (OMC), plastic limit (PL) and unconfined compressive strength (UCS) increased with the addition of Costus lateriflorus bagasse fibre. Results established that increase bagasse fibre content improved the properties of the soil suitable for road construction. However, the bagasse fibre performed better in Laterite soil than clay soil, and 7.5% bagasse fibre would be appropriate for use as stabilization material in soil with similar characteristics like the Laterite and clay soil along Ubeta-Ula-Ubie road.

Nowadays many researchers are focused on the sytnhesis of nanoscale tricobalt tetraoxide (Co3O4) particles, owing to their unique properties. These particles have indeed many potential technological applications. The present investigation deals with the fabrication of this spinel oxide: it was successfully synthesized through a friendly environmental method, using cobalt (II) chloride as cobalt precursor and aqueous extract of Moringa oleifera leaves. The latter contains alkaloids as a base source while flavonoids present in the leaves acted as capping agent to prevent the particles agglomeration. Alkaloids present in the leaves were hydrolyzed in water and consequently, hydroxilated Co2+ leads to the formation of Co3O4 powder via calcination. The electronic transmission microscopy has revealed the single crystalline nanorods morphology of the synthetised materials. These nanorods are about several hundred nanometers long and several tens of nanometers in diameter. The bulk Co3O4 is known to be antiferromagnetic, the vibrating sample magnetometer data (at room temperature) of the prepared powder exhibited the lower coercivity and remanence, signaling that the produced spinel was pure and was constituted of superparamagnetic particles made of Co3O4. The UV–visible spectrum exhibited a photoluminescence peak in the visible light range positioned at about 538nm, suggesting this spinel as a visible light emitting material and as photocatalyst under visible light.