48 research outputs found
Determinants of food security among households in Nigeria
Background and Objective: Although the government has demonstrated a commitment to confronting the issue of food security in Nigeria with different policies, the result indicates that the target is far from being realized, as the country is still listed among the hungry and food-insecure nations. More than 50% of the household income goes to meeting food requirements. This paper was attempted to explore the factors affecting food security status among urban and rural households in Nigeria. Materials and Methods: Using the econometric method, the study used the food consumption score as a proxy for food security to measure the impact of some determinants of household food security on rural and urban households in Nigeria.
Results: The result of the ordinary least square (OLS) analysis and the multinomial log it models revealed that education, food and non-food expenditures and the number of adults have a significant positive influence on food security. However, age, gender and household size affect food security slightly and negatively. Land size was expected to be positively affect food security but it was insignificant, which can be explained by the land acquisition and ownership system of the country. Conclusion: The findings of this study suggest that the government needs to intensify efforts for programs that will promote the education of household headsʼ by improving the access of poor households to formal education, increasing income, increasing social capital and reviewing land ownership policies to allow for the transfer of land to rural house holds. These efforts will create opportunities for improving food security in the country
Sulphated zirconia catalysed conversion of high density polyethylene to value-added products using a fixed-bed reactor
Evaluation of cubic, PC-SAFT, and GERG2008 equations of state for accurate calculations of thermophysical properties of hydrogen-blend mixtures
Hydrogen (H2) is a clean fuel and key enabler of energy transition into green renewable sources and a method of achieving net-zero emissions by 2050. Underground H2 storage (UHS) is a prominent method offering a permanent solution for a low-carbon economy to meet the global energy demand. However, UHS is a complex procedure where containment security, pore-scale scattering, and large-scale storage capacity can be influenced by H2 contamination due to mixing with cushion gases and reservoir fluids. The literature lacks comprehensive investigations of existing thermodynamic models in calculating the accurate transport properties of H2-blend mixtures essential to the efficient design of various H2 storage processes. This work benchmarks cubic equations of state (EoSs), namely Peng–Robinson (PR) and Soave Redlich–Kwong (SRK) and their modifications by Boston–Mathias (PR-BM) and Schwartzentruber–Renon (SR-RK), for their reliability in predicting the thermophysical properties of binary and ternary H2-blend mixtures, including CH4, C2H6, C3H8, H2S, H2O, CO2, CO, and N2, in addition to Helmholtz-energy-based EoSs (i.e., PC-SAFT and GERG2008). The benchmarked models are regressed against the experimental data for vapor–liquid equilibrium (VLE) that covers a wide range of pressures (0.01 to 101 MPa), temperatures (92 K to 367 K), and mole fractions (0.001 to 0.90) of H2. The novelty of this work is in benchmarking and optimizing the parameters of the mentioned EoSs to study VLE envelopes, densities, and other critical transport properties, such as heat capacity and the Joule–Thomson coefficient of H2 mixtures in a wide range of associated conditions. The results highlight the significant effect of the temperature-dependent binary interaction parameters on the calculations of thermophysical properties. The SR-RK EoS demonstrated the highest agreement with VLE data among the cubic EoSs with a low root mean square error and absolute average deviation. The PC-SAFT VLE models demonstrated results comparable to the SR-RK. The sensitivity analysis highlighted the high influence of impurity on changing the thermophysical behavior of H2-blend streams during the H2 storage process
An Investigation of the Reliability of Senior Secondary School Certificate Examination (SSSCE) Results in Gombe Metropolis, Gombe State, Nigeria
This paper tests the reliability of the results obtained by students who sat for National Examination council Examination (NECO). Using the result obtained by the students in the same school in WAEC. The paper finds the correlation coefficients of percentage achievement in Mathematics and English – language in WAEC and NECO. The correlation coefficient was found for two consecutive years 2012 and 2013. It was observed that the correlation coefficients between the two examination bodies in 2012 are o.61 in Mathematics and 0.77 in English – language. In 2013, the correlation coefficient between WAEC and NECO are 0.87 in Mathematics and 0.24 in English – language. Except for that of English – language in 2013, the other correlation coefficients are positive and close to perfect. This shows that there is a strong relationship between the achievements. Keywords: West Africa Examination Council (WAEC), National Examination Council (NECO), Correlation Coefficient, Relationship, Percentage achievement, Candidate, Credit
Influence of organic molecules on wetting characteristics of mica/H2/brine systems: Implications for hydrogen structural trapping capacities
Hypothesis:
Actualization of the hydrogen (H2) economy and decarbonization goals can be achieved with feasible large-scale H2 geo-storage. Geological formations are heterogeneous, and their wetting characteristics play a crucial role in the presence of H2, which controls the pore-scale distribution of the fluids and sealing capacities of caprocks. Organic acids are readily available in geo-storage formations in minute quantities, but they highly tend to increase the hydrophobicity of storage formations. However, there is a paucity of data on the effects of organic acid concentrations and types on the H2-wettability of caprock-representative minerals and their attendant structural trapping capacities.
Experiment:
Geological formations contain organic acids in minute concentrations, with the alkyl chain length ranging from C4 to C26. To fully understand the wetting characteristics of H2 in a natural geological picture, we aged mica mineral surfaces as a representative of the caprock in varying concentrations of organic molecules (with varying numbers of carbon atoms, lignoceric acid C24, lauric acid C12, and hexanoic acid C6) for 7 days. To comprehend the wettability of the mica/H2/brine system, we employed a contact-angle procedure similar to that in natural geo-storage environments (25, 15, and 0.1 MPa and 323 K).
Findings:
At the highest investigated pressure (25 MPa) and the highest concentration of lignoceric acid (10−2 mol/L), the mica surface became completely H2 wet with advancing (θa= 106.2°) and receding (θr=97.3°) contact angles. The order of increasing θa and θr with increasing organic acid contaminations is as follows: lignoceric acid \u3e lauric acid \u3e hexanoic acid. The results suggest that H2 gas leakage through the caprock is possible in the presence of organic acids at higher physio-thermal conditions. The influence of organic contamination inherent at realistic geo-storage conditions should be considered to avoid the overprediction of structural trapping capacities and H2 containment security
Aphrodisiac Potentials of Aqueous Extract of Azanza Garckeana Fruit Pulp in Fluoxetine-induced Sexually-impaired Female Rats
This study aims to investigate the potential of Azanza garckeana, a plant traditionally used as an aphrodisiac, to reverse sexual dysfunction induced by an antidepressant ‘fluoxetine’ in female rats. Aqueous extract of A. garckeana fruit pulp was screened for its secondary metabolite compositions. Female rats were induced into sexual dysfunction using fluoxetine, then they were divided into six groups, and treated based on the group with oral administration of varying doses of A. garckeana extract (125, 250, and 500 mg/kg body weight) and a reference medication (Tadalafil) for seven days. Sexual behaviour parameters were monitored and hormone levels (progesterone, follicle-stimulating hormone, luteinizing hormone, oestrogen, and prolactin) were measured after the treatment period. Fluoxetine significantly (p < 0.05) reduced the frequencies of sexual behaviours in the rats, such as darting, hopping, lordosis, genital grooming, and licking behaviour, but increased the latencies of darting and hopping. However, the extract, at 250 and 500 mg/kg, significantly (p < 0.05) reversed these changes in the sexual behavior of fluoxetine-induced rats in comparison to the effects of Tadalafil treatment. Furthermore, the extract significantly (p < 0.05) increased the levels of luteinizing hormone, follicle-stimulating hormone, progesterone, and prolactin in the blood but decreased oestrogen levels, especially at a dose of 500 mg/kg. The results of this study suggest that the aqueous extract of A. garckeana fruit pulp can improve sexual behavior and reproductive hormone concentrations, thereby potentially restoring sexual competence in sexually-dysfunctioned female rats. These findings provide additional support for the traditional use of A. garckeana in managing female sexual dysfunction
Influence of pressure, temperature and organic surface concentration on hydrogen wettability of caprock, implications for hydrogen geo-storage
Hydrogen (H2) as a cleaner fuel has been suggested as a viable method of achieving the de-carbonization objectives and meeting increasing global energy demand. However, successful implementation of a full-scale hydrogen economy requires large-scale hydrogen storage (as hydrogen is highly compressible). A potential solution to this challenge is injecting hydrogen into geologic formations from where it can be withdrawn again at later stages for utilization purposes. The geo-storage capacity of a porous formation is a function of its wetting characteristics, which strongly influence residual saturations, fluid flow, rate of injection, rate of withdrawal, and containment security. However, literature severely lacks information on hydrogen wettability in realistic geological and caprock formations, which contain organic matter (due to the prevailing reducing atmosphere). We, therefore, measured advancing (θa) and receding (θr) contact angles of mica substrates at various representative thermo-physical conditions (pressures 0.1-25 MPa, temperatures 308–343 K, and stearic acid concentrations of 10−9 - 10−2 mol/L). The mica exhibited an increasing tendency to become weakly water-wet at higher temperatures, lower pressures, and very low stearic acid concentration. However, it turned intermediate-wet at higher pressures, lower temperatures, and increasing stearic acid concentrations. The study suggests that the structural H2 trapping capacities in geological formations and sealing potentials of caprock highly depend on the specific thermo-physical condition. Thus, this novel data provides a significant advancement in literature and will aid in the implementation of hydrogen geo-storage at an industrial scale
Enhancing wettability prediction in the presence of organics for hydrogen geo-storage through data-driven machine learning modeling of rock/H2/brine systems
The success of geological H2 storage relies significantly on rock–H2–brine interactions and wettability. Experimentally assessing the H2 wettability of storage/caprocks as a function of thermos-physical conditions is arduous because of high H2 reactivity and embrittlement damages. Data-driven machine learning (ML) modeling predictions of rock–H2–brine wettability are less strenuous and more precise. They can be conducted at geo-storage conditions that are impossible or hazardous to attain in the laboratory. Thus, ML models were utilized in this research to accurately model the wettability behavior of a ternary system consisting of H2, rock minerals (quartz and mica), and brine at different operating geological conditions. The results revealed that the ML models accurately captured the wettability behavior at different geo-storage conditions by yielding less than 5% mean absolute percent error and above 0.95 coefficient of determination values. The partial dependency or sensitivity plots were generated to evaluate the impact of individual features on the trained models. These plots revealed that the models accurately captured the physics behind the problem. Furthermore, a mathematical equation is derived from the trained ML model to predict the wettability behavior without using any ML software. The accuracy of the predictions of the ML model can be beneficial for exactly predicting the H2 geo-storage capacities and assessing of H2 containment security of storage and caprocks for large-scale geo-storage projects
Saudi Arabian basalt/CO2/brine wettability: Implications for CO2 geo-storage
The geological sequestration of carbon dioxide, including mineralization in basaltic formations, has been identified as a promising method of attaining a low-carbon economy. However, successful CO2 storage depends on both the CO2 wettability of the basaltic rocks and the basalt rock-fluid interfacial interactions. The contact angles of brine/CO2 systems for Western Australian (WA) and Iceland basalts have been recently reported in the literature. However, contact angle datasets for evaluating the CO2 wettability of Saudi Arabian (SA) basalt have not been previously reported. Moreover, there is limited information on the impact of organic acids on the wettability of the basalt/CO2/brine system. In the present study, the contact angles of supercritical CO2/brine systems on SA basalt are measured at temperatures of 298 and 323 K, and at various pressures of 0.1 – 20 MPa in the absence and presence of organic acid (10 − 2 mol/L stearic acid). Various analytical methods are used to characterize the SA basalt surface, and the wetting behavior of the SA basalt is compared with that of the WA and Iceland basalts. The quantity of CO2 that can be safely trapped underneath the SA basalt (in terms of CO2 column height) is then computed from the experimental data. At the highest tested temperature and pressure (20 MPa and 323 K), the pure SA basalt is found to remain strongly water-wet, with advancing (θa) and receding (θr) contact angles of 46.7° and 43.2°, respectively, whereas the Iceland basalt becomes moderately water-wet (θa = 85.1° and θr = 81.8°), and the WA basalt becomes CO2-wet (θa = 103.6° and θr = 96.1°). However, the organic-aged SA basalt attains a CO2-wet state (θa = 106.8° and θr = 95.2°). In addition, the CO2 column height of the pure SA basalt is higher than that reported for the WA and Iceland basalts. Further, at 323 K, the CO2 column height decreases from 835 m at 5 MPa to −957 m at 20 MPa. These results suggest that there could be both freer plumb and lateral movement of CO2 into the SA basalt in the presence of organic acid, thus resulting in lower residual and mineral trapping capacities, and fewer eventual leakages of CO2, across the geological formation
Effect of methylene blue on wetting characteristics of quartz/H2/brine systems: Implication for hydrogen geological storage
Hydrogen (H2) is considered a promising replacement for fossil fuels due to its enormous potential as an environmentally friendly and sustainable option compared to carbon-based fossil fuels. However, storing the vast quantity of H2 required to satisfy the global energy demand on the earth\u27s surface can be difficult due to its compressibility and volatility. The best option for large-scale storage is underground H2 storage (UHS), which can be retrieved when needed. Rock wettability is vital in UHS because it determines the H2 storage capacity, containment security, and potential withdrawal and injection rates. Organic acid inherent in storage formations could make the storage rock H2-wet and reduce the residually trapped H2; thus, recent research efforts have concentrated on modifying sandstone formations contaminated with organic acid through chemical injections, such as nanofluids and methyl orange. However, previous research has not considered applying methylene blue (MB) as a rock wettability modifier to promote successful UHS. In addition, MB is a toxic constituent of wastewater, causing pollution. This research aims to dispose of MB in underground reservoirs to alter the wettability and increase the H2 storage capacity, mitigating anthropogenic carbon dioxide emissions. We assess the application of MB as a chemical agent for altering the wettability of quartz contaminated with stearic acid to promote H2 geological storage. Based on the contact-angle measurements, quartz aged with the optimum concentration of MB (100 mg/L) has the least advancing ( a= 35°), and receding ( r= 32°) angles at 13 MPa and 50 °C, changing the wettability to strongly water-wet. We demonstrate that an injection of MB into geological formations could make the rock water-wet, promoting H2 containment security and assisting in the large-scale implementation of UHS