OIL

This study was carried out to investigate the effects of the water-soluble fractions of spent and
unspent engine oil on two microalgae, Chlorella vulgaris and Scenedesmus ecornis. The test algae
were exposed to varying concentrations (0%, 5%, 10%, 25%, 50%, 75% and 100%) which were
set up in triplicates. The growth response was monitored every two days for 14 days using a visible
spectrophotometer (Model No. HV-721). The percentage inhibition, dry weight and analysis of
variance (ANOVA) were calculated using Microsoft Excel software. Physicochemical parameters
such as pH, electrical conductivity and total dissolved solids were measured using the appropriate method. The results revealed that growth of both microalgae decreased progressively with increasing concentration, with spent engine oil exhibiting greater toxicity than unspent engine oil. Growth rate analysis consistently favored Chlorella vulgaris in both engine oil. Statistical analysis using ANOVA indicated that it was significant (p< 0.0001) in growth response among the various concentrations for both species. The dry weight analysis revealed that in spent engine oil, the highest cumulative dry weights occurred in the control (391.23 mg/L for Scenedesmus ecornis and 394.24mg/L for Chlorella vulgaris), with marked reduction at 75-100%, with both species recording their lowest biomass at 100% (104.13 mg/L for Scenedesmus ecornis and 117.97 mg/L for Chlorella vulgaris) while in unspent engine oil, dry weight remained relatively high at 5-10% Percentage inhibition analysis revealed growth stimulation at low concentrations (5-10%), particularly in Scenedesmus ecornis exposed to unspent engine oil. In spent engine oil, Scenedesmus ecornis exhibited higher sensitivity than Chlorella vulgaris, while in unspent engine oil, Chlorella vulgaris exhibited greater sensitivity. The total dissolved solids, electrical conductivity, and pH decreased significantly across all concentrations. Spent engine oil is more toxic to microalgae than unspent oil, and the result indicates that Chlorella vulgaris is more suited for bioremediation of aquatic environments contaminated with unspent engine oil, while Scenedesmus ecornis show stronger potential for the bioremediation of water bodies polluted with spent engine oil.

This study investigates the comparative effects of oil and non-oil exports on economic growth in Nigeria from 1990 to 2022. Using regression analysis, the research examines how changes in investment, oil exports, non-oil exports, and exchange rates impact Real Gross Domestic Product (RGDP). The findings reveal that non-oil exports significantly and positively influence economic growth, emphasizing the necessity of diversifying Nigeria's export base. Conversely, oil exports show a negative but statistically insignificant effect on RGDP, indicating limited impact despite the sector's economic prominence. Additionally, exchange rate depreciations positively affect economic growth by enhancing export competitiveness. However, investment changes do not exhibit a statistically significant effect on RGDP within the model. The study underscores the importance of policies aimed at export diversification, competitive exchange rate management, and investment attraction to foster sustainable and inclusive economic growth in Nigeria. The results suggest that reducing dependence on oil revenues and promoting non-oil sectors are critical for economic resilience and long term development.

Lipids, including fats, sterols, and fat-soluble vitamins, play essential roles in energy storage, cell signaling, and cellular structure, making them vital to biological systems and industries such as food, cosmetics, and nanotechnology. Seafood, particularly fish like *Scomber scombrus* (Atlantic mackerel), is rich in omega-3 fatty acids, which provide numerous health benefits, including protection against heart diseases and oxidative stress. This study investigates the hydroxyl radical scavenging activity of fish oil extracted from *Scomber scombrus* using various preparation methods (raw, marinated, boiled, and fried). The antioxidant potential of the oil, assessed through its ability to inhibit malonaldehyde (MDA) formation via the Fenton reaction, revealed that raw cured samples exhibited the highest scavenging activity, while boiled samples showed the lowest. These findings highlight the benefits of curing to preserve antioxidant properties in fish oil and suggest its potential application in mitigating oxidative stress-related diseases. Additionally, the research underscores the importance of lipids and omega-3s in seafood quality, preservation, and overall human health. Further exploration of cooking methods and antioxidant stability is recommended to enhance the nutritional value of seafood.

The study empirically examined the relative contribution of oil and non-oil subsector to export trade in Nigeria. The Augmented Dickey Fuller unit root test was employed to test for the order of integration of the series. It was found to be stationary at first and second differ ences. Then the Johansen Co-integration technique was employed to determine if there is long run relationship between the dependent and independent variables of the model. Furthermore, the Vector Error Correction Mechanism technique (VECM) was used to estimate the regression coefficients and to correct for any disequilibrium between the short run and long run dynamics of the model. The short run and long run version of the model were specified. Results showed that, oil sector was correctly signed and was statistically significant. The study therefore recommends, among others, that proper and effectively outlined policy frameworks should be put in place by the government through the relevant agencies to ensure that non-oil sector is effectively managed and channeled towards contributing significantly to export in Nigeria. This will go a long way in ensuring that the contributions of oil to export in Nigeria is significantly reduced