Adekunle Ajasin University

This study focused on the development of insulating refractory bricks using quartzite, with a comprehensive analysis of their mechanical and thermal properties. The bricks were made from quartzite with 10% bentonite binder and water, added for mixing. Various tests were done (Xray Fluorescence, Thermogravimetric and Differential Thermal Analyses, apparent porosity, shrinkage, Loss on Ignition (LOI), compressive yield stress, and water absorption (WA)), following American Society for Testing and Materials' procedures. Microstructural analysis of the sample was observed using Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDS). These results provided valuable insights into the stability of the developed refractory bricks at high temperatures. Analysis of chemical composition from quartz bricks revealed significant SiO2 content (94.303%), emphasizing the material's superior refractory properties. LOI (0.5%) and shrinkage (0.2%) results indicated enhanced performance with good thermal stability and strength. Compressive stress yield indicated that the material exhibits good strength relative to the amount of binder used. WA results confirmed that the brick sample is suitable for high-temperature applications. SEM/EDS analysis unveiled intricate microstructural features, affirming the bonding agent's influence on the material's composition.

Mosses and lichens are effective bioindicators because they absorb nutrients and pollutants directly from the atmosphere, allowing them to accumulate metals and nutrients. This study evaluated mosses and lichens as bioindicators of heavy metals and nutrients in a regrowth forest at Obafemi Awolowo University, Southwestern Nigeria. Vegetation assessment was conducted using 16 plots of 25 m × 25 m, and 111 moss and 383 lichen samples were collected between November and December, where total enumeration and tree species identification were done in the regrowth forest. The diameter at breast height (DBH) of all tree species was measured at breast height for trees above > 3 m and at the mid-point for trees < 3 m in height. Result showed that dominant trees with lichen presence on their bark were Azadirachta indica, Dracaena manii, while, Dracaena manii had highest number of occurrence of mosses with lowest number mosses occurrences in Azadirachta indica and Annona reticulate. The lowest values of lichen characterized with host trees with smooth bark while the distribution and number of mosses were equally distributed on both rough and smooth bark. Nutrients concentration across the mosses and lichens species is in this order: C > Ca > K > Mg > P > Na. The level of heavy metals such as Zn, Fe and Cu in mosses and lichen was found to be significantly different (P < 0.05). Conversely, the level heavy metals (Pb and Cd) found in the species were not significantly different but highest in Hyophila involute and lower in Lecanoral expallens. The order of heavy metals concentration in mosses and lichens is in order: Fe > Zn > Cu > Pb > Cd. Mosses absorb more Zn, Fe and Cu in forest ecosystems compared to lichen, and factors such as DBH. and bark texture contributed to structural changes in mosses and lichen community.

Groundwater management is vital to community health and ecosystem sustainability. This study assessed the influence of telecommunication mast operations and maintenance activities on shallow groundwater quality in Ikare-Akoko, Nigeria, using an integrated approach that combined regression-based geohydraulic parameters, hydrogeological–engineering tests, and resistivity surveys. Ten groundwater samples and five subsoil samples were analyzed for chemical and heavy metal concentrations (pH, TDS, Cr, Cu, Cd, Mn, Pb, Fe) and soil properties, while five Schlumberger vertical electrical soundings (VES) were used to determined subsurface resistivity. Elevated Fe concentrations (0.636–0.705 mg/L), above WHO standards (< 0.5 mg/L), were detected in mast-affected wells—likely from infrastructure corrosion and operational residues that mobilize Fe under local soil–groundwater conditions—whereas control sites remained within permissible limits. Geotechnical tests revealed loosely compacted sandy–clay loam with medium infiltration capacity, while VES results delineated four lithologic layers with HA, AA, and KH curve types. Derived geohydraulic indices, including Aquifer Vulnerability Index (AVI: − 0.0096 to 0.0926) and longitudinal conductance (0.0437–0.1018 mhos), indicate high susceptibility of weathered aquifers to contamination due to weak protective cover. Health risk assessment revealed no immediate risks for adults or children via ingestion or dermal exposure. Correlation analysis showed strong links between soil fines percentage, infiltration rate, and groundwater protective capacity. These findings highlight the need for continuous monitoring and proactive remediation around telecommunication masts to safeguard groundwater quality and public health.

This research examined the water quality in the Asese/Mowe Industrial Area of Ogun State, Nigeria. Twenty (20) water samples comprising both surface and groundwater sources were obtained from industrial zones and subjected to comprehensive physicochemical analysis using standard procedures. The analytical parameters examined encompassed pH levels, electrical conductivity (EC), total dissolved solids (TDS), dissolved oxygen (DO), biological oxygen demand (BOD), chemical oxygen demand (COD), and principal anionic constituents (chloride (Cl⁻), sulphate (SO42⁻), and nitrate (NO3⁻)). Surface and groundwater quality analysis was evaluated using water quality index (WQI). 14 out of the evaluated 20 samples had pH below the minimum acceptable limit of 6.5, indicating that the water in many locations is slightly acidic. The COD values varied between 3.99 and 12.04 mg/l, with a mean value of 7.09 (± 1.88) mg/l. SW1 exhibits a COD level of 12.04 mg/L, which fails to comply with the required COD standards and consequently renders it unsuitable for drinking water consumption based on COD criteria. Results show that the WQI values for the 20 samples ranged between 6.83 and 106.73 reflecting noticeable variation in water quality across different sampling points. 45

Nurses often experience high occupational stress and irregular work schedules, which may be compounded by emerging behavioral patterns such as excessive social media use. However, the role of social media addiction in work-family conflict (WFC), particularly through its impact on sleep quality, remains underexplored. This study examined the relationship between social media addiction and WFC among nurses, with sleep quality as a potential mediator. A cross-sectional survey design was employed to collect data from 250 nurses (60 males and 190 females) working in public hospitals in the southwestern region of Nigeria. Standardized and validated instruments assessed social media addiction, sleep quality, and WFC. Mediation analyses using Hayes' PROCESS macro with 5,000 bootstrap samples revealed that social media addiction was significantly positively associated with WFC in both directions: work interference with family and family interference with work. Sleep quality partially mediated these relationships, indicating that higher social media addiction predicts poorer sleep quality, which in turn exacerbates WFC. These findings suggest that workplace behavioral health programs, such as employee wellness initiatives, stress management workshops, and digital well-being interventions that promote sleep quality and responsible social media use, can help reduce work-family conflict and enhance nurses' well-being and performance.