University of Cross River State

Ewa W.O., Ugwu O.O.

Security vulnerability assessments are crucial for the sustainable development of critical infrastructure amid intensifying global environmental and socio-economic challenges. This study employs a scientometric analysis of 247 bibliographic records from the Web of Science database (2002–2022) to explore research trends and developments. A novel contribution is the mapping of research priorities before and after the 2015 United Nations Sustainable Development Goals (SDGs) declaration, illustrating a shift from "critical infrastructure" to "resilience," a perspective not comprehensively addressed in prior reviews. Using CiteSpace, the study identifies key research clusters, collaborative networks, and keyword evolutions, providing a robust, quantitative depiction of the field’s intellectual structure. The research highlights the significant roles of the USA, Italy, and China, and the influence of journals like Reliability Engineering and System Safety and Natural Hazards. It uncovers underexplored areas such as the integration of GIS, artificial intelligence, and digital twins into vulnerability assessments, positioning the research to tackle contemporary challenges, particularly climate change adaptation. These findings offer valuable insights into the evolving dynamics of infrastructure sustainability and resilience. The study emphasizes the necessity of cross-disciplinary collaborations and innovations, guiding future research and policy-making to strengthen infrastructure protection in a rapidly changing global context. This comprehensive knowledge mapping provides actionable insights for policymakers, academics, and practitioners aiming to develop robust, sustainable infrastructure strategies.

Ubah C.B., Akem M.U., Benjamin I., Edet H.O., Adeyinka A.S., Louis H.

Retraction of ‘Heteroatoms chemical tailoring of aluminum nitrite nanotubes as biosensors for 5-hydroxyindole acetic acid (a biomarker for carcinoid tumors): insights from a computational study’ by Chioma B. Ubah et al., Mol. Syst. Des. Eng., 2024, 9, 832–846, https://doi.org/10.1039/D4ME00019F.

Ante J.E., Ineh M.P., Achuobi J.O., Akai U.P., Atsu J.U., Offiong N.O.

This paper investigates the asymptotic eventual stability (AE-S) for nonlinear impulsive Caputo fractional differential equations (ICFDEs) with fixed impulse moments, employing auxiliary Lyapunov functions (ALF) which are specifically constructed as analogues of vector Lyapunov functions (VLF). A novel derivative tailored for VLF is introduced, offering a more robust framework than existing approaches based on scalar Lyapunov functions (SLF). Adequate conditions for AE-S involving ICFDEs are provided. We also used the predictor corrector method to implement a numerical solution for a given impulsive Caputo fractional differential equation. These findings extend and improve upon existing results, providing significant advancements in the stability analysis of systems with memory effects and impulsive dynamics. The study holds practical relevance for modeling and analyzing real-world systems, including control processes, biological systems, and economic dynamics where fractional-order behavior and impulses play a crucial role.

Asogwa F.C., Asogwa C.J., Ekpong B.O., Oluwadamilola D., Igomah G.O., Abualanke R.G., Chisom K.N.

This study employed a density functional theory (DFT) approach to study the detection and adsorption of cefuroxime on metal-doped graphene decorated with biodegradable polymers using the DFT/ꞷB97XD/6–311 + G (2d, 2p) theory. The geometry optimization analysis demonstrated that the modified surfaces (Co@GP, Fe@GP, and Ni@GP, DLL_Co@GP, DLL_Fe@GP, and DLL_Ni@GP, and GCL_Co@GP, GCL_Fe@GP, and GCL_Ni@GP) interacted with cefuroxime (CFX), and the variation in the respective bond length was small, showing the possibility of the surfaces adsorbing the pollutant and retaining the original structural orientation. A decrease in the energy gap is observed for Co@GP and Fe@GP, whereas that of Ni@GP significantly increased from 3.64 to 4.40 eV. The adsorption of the studied drug molecules on the lactide-decorated systems results in an increase in the Eg of DLL_Fe@GP and DLL_Ni@GP from 4.31 to 4.37 eV and from 2.63 to 4.42 eV, respectively. A slight decrease from 4.20 to 4.17 eV is reported for DLL_Co@GP. Moreover, the glycolide decoration produced a decrease in Eg for GCL_Co@GP from 5.55 to 3.94 eV and a negligible difference of 0.02 eV for GCL_Fe@GP from 4.95 to 4.93 eV, while an increase from 4.51 to 4.69 eV was obtained for GCL_Ni@GP. The adsorption energy analysis revealed that the adsorption strength decreased in the order GCL_Ni@GP (− 16.60 eV) > DLL_Co@GP (− 4.90 eV) > Co@GP (− 4.62 eV) > DLL_Ni@GP (− 2.18 eV), and these materials could effectively adsorb pollutants, whereas Fe@GP, Ni@GP, DLL_Fe@GP, GCL_Co@GP, and GCL_Fe@GP exhibited physisorption.

Ikeuba A.I., Usibe B.E., Essiet N., Sonde C.U., Ita B.I., Abeng F.E., Etim A.A.

This work aims to evaluate the anti-corrosion potential of ethyl dimethyl propylammonium bis (trifluoromethyl sulfonyl) imide (EDMPA-TFSI)-ionic liquid on AA3003 alloy in 0.5 M HCl solution in the presence and absence of potassium iodide at ambient and elevated temperatures. The corrosion inhibition of AA3003 alloy by EDMPA-TFSI in the presence of potassium iodide was evaluated using hydrogen evolution measurements at 303 K and 333 K. The results show that in the absence of potassium iodide, EDMPA-TFSI decelerates AA3003 corrosion in an acidic medium with a maximum inhibition efficiency of 93.2 % and 90.5 % obtained at 303 K and 333 K respectively. In the presence of potassium iodide, 94.7 % and 89.8 % inhibition efficiencies were obtained at 303 K and 333 K, respectively. This adsorption behavior is concordant with the Langmuir adsorption isotherm and the corrosion process in the presence of EDMPA-TFSI shows consistency with first-order reaction kinetics. New information on the application of EDMPA-TFSI as a workable corrosion inhibitor is provided herein.

Ntui T.N., Anozie R.C., Edet H.O., Agurokpon D.C., Favour Azogor N., Imojora B.

Carbaryl gas has detrimental impacts on both the environment and human health; therefore, the development of an efficient adsorbent may help reduce the risks this gas poses. In this study, Si-doped and transition metal (Ni, Pt, and Pd) decorated graphene/boron nitride (GP_BN) heterostructures were systematically analyzed for their potential as adsorbents for carbaryl gas. The geometric properties reveal that the inclusion of Si, Ni, Pt, and Pd significantly alters the structural attributes, enhancing reactivity and adsorption capabilities. HOMO-LUMO analysis showed that the Si@GP_BN model had the highest stability (Eg = 0.836 eV), while SiPt@GP_BN exhibited the highest conductivity (Eg = 0.005 eV). Upon interaction with carbaryl gas, most complexes demonstrated an increase in energy gap, indicative of diverse electronic responses. Second-order perturbation energy analysis highlighted strong donor-acceptor interactions, with notable stabilization energies, especially in SiPt@GP_BN systems. Surfaces displayed similar electron transfer behavior, supported by closed work function energy values (2.989 to 3.956 eV). Charge transfer results indicated polar covalent bond formation, with high dipole moments, especially at the oxygen site. Adsorption energies at the oxygen site (13.494 to 19.820 eV) suggested chemisorption, while nitrogen site adsorption (>200 eV) implied physisorption. Adsorption studies indicated that carbaryl is more feasibly adsorbed at oxygen sites due to lower adsorption energies. QTAIM, ELF, and NCI analyses confirmed the non-covalent nature of interactions, with hydrogen bonds and van der Waals forces playing crucial roles. These findings collectively highlight the potential of Si-doped and transition metal-decorated graphene/boron nitride nanocomposites as effective adsorbents for carbaryl gas, offering insights into their electronic properties and interaction mechanisms.

Ajaba M.O., Agbo B.E., Umoh N., Udoh E.S., Gulack A.O., Ushie A., Izachi F.O., Ateb B.C.

Wound infection poses a significant global health threat, as it is a leading cause of morbidity and mortality among surgical patients and individuals with burn injuries, resulting in substantial healthcare burdens and devastating outcomes worldwide. Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli have frequently been implicated as major pathogens causing wound infections. This has eventually and consistently given rise to antimicrobial resistance divulging a need to mitigate infectious outbreaks. Herein, we employed a computational density functional theory (DFT) method at ωB97XD/6-311++g(d, p) level of theory to evaluate the performance of the thiophene derivative 5-(4-bromo-5-(methylthio)thiophen-2-yl)-4-phenyl-4H-1,2,4-triazole-3-thiol 4, which is experimentally synthesized into five compounds (4a, 4b, 4c, 4d, and 4e). The chemical reactivity, kinetic stability, nature of interactions and functional characteristics of the thiophene derivatives were ascertained. The resistance gene PDB ID: 1K25, 2D45, 4UOT, and 7K2X were employed and docked with thiophene derivatives. Interestingly, molecular docking analysis demonstrated that ligands 4a, 4b, 4c, 4d, and 4e are more effective against proteins 1K25, 4U0T and 7K2X than amoxicillin and methicillin. Upon docking with the 2D45 protein, compounds 4c and 4e (− 5.9 kcal/mol) exhibited potential similar to that of methicillin (− 5.9 kcal/mol), while 4a and 4b showed slightly better affinities (− 6.1 kcal/mol and 6.0 kcal/mol). Using Lipinski's Rule of Five (Ghose filter, Veber rules, Muegge filter, and Egan's rule), 4d and 4e were determined to be the most promising candidates for drug development due to their compliance with all evaluated criteria, indicating favourable properties for oral bioavailability and drug likeness. This research suggested that thiophene derivatives can serve as promising antibacterial agents against wound-infected bacteria.

Godfrey O.C., Edo G., Nwoko M.C., Gulack A.O., Okon G.A., Edim M.M.

Abstract Owing to the growing prevalence of uropathogenic Escherichia coli (UPEC) strains that are more recently resistant to last-line antibiotic treatments, such as carbapenems and colistin drugs, urinary tract infections (UTIs) are a prime example of the antibiotic resistance crisis and emphasize the need for new approaches to treat and prevent bacterial infections. The antibacterial effect of 4-((5-bromo-2-hydroxybenzlidene) amino)-1,5-dimethyl1-2-phenyl-1,2-dihydro-3H-pyrazol-3-one (BDP), a Schiff base derivative, was tested against UPEC, a bacterium responsible for urinary tract infections. This Schiff base compound was optimized in five phases at the ωB97XD/6–311++G(2d,2p) level of theory; therefore, density functional theory studies, spectroscopic analysis, molecular docking analysis, and pharmacokinetic prediction were employed. The stability of the BDP compound was predicted via geometric structural studies, natural bond orbital (NBO) theory, quantum chemical descriptors, and spectral studies such as FT-IR and UV‒vis studies. The ab initio calculation of NBO revealed greater stability of the compound despite the solvation effects of DMSO, methanol, ethanol, and water. This claim was supported by frontier molecular orbital prediction, where the energy gaps were 6.60 eV, 7.45 eV, 7.45 eV, 7.43 eV, and 7.44 eV for the BDP compound present in the gas phase, water, DMSO, ethanol and methanol, respectively. The molecular docking results revealed the antibacterial efficacy of BDP. 5C5Z + BDP and 5VQ5+BDP interactions produced −4.5 and −5.4 kcal/mol binding affinities respectively. BDP displayed stronger interaction with 5VQ5 than with 5C5Z and had better docking activities than FOS. Overall, result has shown that BDP is a potential therapeutic candidate for the treatment of UPEC caused UTIs and has the potential to mitigate the challenges associated with urinary tract infections, hence, should be considered a promising candidate for UTI treatment.

Ogarekpe N.M., Agunwamba J.C., Tenebe I.T., Udodi O., Chinedu A.D.

ABSTRACT The integrated solar and hydraulic jump-enhanced waste stabilization pond (ISHJEWSP) has been proposed as a solution to enhance performance of the conventional WSP. Despite the better performance of the ISHJEWSP, there is seemingly no previous study that has deployed machine learning (ML) methods in modelling the ISHJEWSP. This study is aimed at determining the relationships between the ISHJEWSP effluent parameters as well as comparing the performance of extra trees (ET), random forest (RF), decision tree (DT), light gradient boosting machine (LightGBM), gradient boosting (GB), and extreme gradient boosting (XGBoost) methods in predicting the effluent biochemical oxygen demand (BOD5) in the ISHJEWSP. The feature importance technique indicated that the most important parameters were pH, temperature, solar radiation, dissolved oxygen (DO), and total suspended solids. These selected features yielded strong correlations with the dependent variable except DO, which had a moderate correlation. With respect to coefficient of determination and root mean square error (RMSE), the XGBoost performed better than the other models [coefficient of determination (R2) = 0.807, mean absolute error (MAE) = 4.3453, RMSE = 6.2934, root mean squared logarithmic error (RMSLE) = 0.1096]. Gradient boosting, XGBoost, and RF correspondingly yielded the least MAE, RMSE, and RMSLE of 3.9044, 6.2934, and 0.1059, respectively. The study demonstrates effectiveness of ML in predicting the effluent BOD5 in the ISHJEWSP.

Nakkeeran G., Krishnaraj L., Shakor P., Alaneme G.U., Otu O.N.

In recent years, building materials made from agricultural waste have become popular due to their lower cost and environmental impact. The Bio-Brick is mixed with Cement-Fly Ash and Hydrated Lime and a fine aggregate of groundnut shell in percentages (20%, 30%, 40%, 50%, and 60%). The optimum mix proportions of Bio-Brick and hydrated lime mortar were found from the compressive strength and were further continued to study the dry density, water absorption, and efflorescence. Machine Learning techniques are used to optimize and predict the properties of Bio-Bricks and mortars. Response Surface Methodology (RSM) and Artificial Neural Networks (ANN) are employed to forecast properties such as compressive strength, dry density, and water absorption with exceptional accuracy. The results from RSM models exhibit high degrees of accuracy, with R-squared values exceeding 0.88 for compressive strength, dry density, and water absorption. ANN models further enhance this predictive power, with R-squared values exceeding 0.99 in predicting these critical properties.

Ertugay C., Edet C.O., Ikot A.N., Lütfüoğlu B.C.

Ettah E.B., Ishaje M.E., Minakova K.A., Sirenko V.A., Bondar I.S.

We studied the structural, electronic, mechanical, and thermodynamic properties of N2CaNa full Heusler alloys using density functional theory (DFT). Results for the structural analysis establish structural stability with a minimum formation energy of 29.9 eV. The compound is brittle and mechanically stable, having checked out with the Pugh criteria. The B/G ratio of bulk modulus B to shear modulus G for N2CaNa is 4.766, hence the material is ductile. N2CaNa alloy is ductile in nature. The Debye model correctly predicts the low-temperature dependence of heat capacity, which is proportional to Debye’s T3 law. Just like the Einstein model, it also recovers the Dulong–Petit law at high temperatures, suggesting the thermodynamic stability of the compounds at moderate temperatures. The results demonstrate potential N2CaNa for applications in spintronics, structural engineering, and other fields requiring materials with tailored properties.

Asogwa F.C., Igwe C.C., Edet H.O., Ikeuba A.I., Imojara A., Igomah G.O., Odey D.O.

The hazards of pollution are highlighted by gas exposure, and creating effective adsorbents is essential for maintaining clean air, the environment, and human health. In our study, employing the DFT/M062x/def2svp level of theory, the potentials of metal-doped (Na, Zn, and Al) fullerene surfaces as efficient adsorbents for CN, CNCl, and NO2 gases were evaluated. Investigation revealed that the introduction of metal dopants has visible impacts on the structural and electronic properties of fullerene surfaces. Specifically, a slight increase in the bond length of C–C bonds, with protruded bonds forming between the doped atoms and carbon atoms, was observed. The obtained energy gap (Eg) demonstrated a consistent reduction across the doped surfaces, indicative of heightened sensitivity toward the gas analytes. C59Al exhibited a higher Eg (3.876 eV), while C59Zn displayed a lower value (3.103 eV) compared to C59Na. Topology analysis using the quantum theory of atoms in molecules (QTAIM) predicted non-covalent interactions between gas analytes and metal-doped fullerene surfaces, a finding that was further substantiated by the analysis of non-covalent interactions. Focusing on CN gas adsorption, distinct behaviors emerged, where C59Na exhibited strong adsorption (Eads = −2.67 eV), surpassing C59Al (−1.82 eV) and C59Zn (−0.64 eV). A similar trend was observed for CNCl and NO2 gas adsorption, with C59Na consistently showing higher adsorption energies. This alignment was corroborated by frontier molecular orbital (FMO) and natural bond orbital (NBO) analyses. The results for dipole moment and recovery time emulated those of adsorption energy, emphasizing the stability and uniformity in adsorbed states. This collective evidence highlights the potential of doped surfaces to effectively adsorb specific gas molecules, offering insights into their applicability in gas sensing and environmental remediation.

Tenebe I.T., Babatunde E.O., Ogarekpe N.M., Emakhu J., Etu E., Edo O.C., Omeje M., Benson N.U.

This study was conducted in Ekpoma, a town dependent on rainwater and river water from nearby areas because of a lack of groundwater sources, and the physicochemical and bacteriological (heterotrophic plate count [HPC], total coliform count [TCC], and fecal coliform count [FCC]) properties of 123 stored river water samples grouped into five collection districts (EK1 to EK5). The results were compared with regulatory standards and previous regional studies to identify water quality trends. While most physicochemical properties met drinking water standards, 74% of samples had pH values > 8.5. Twenty-seven samples were fit for drinking, with EK4 having the highest number of bacterio-logically unsuitable samples. Ten bacterial species were identified, with Gram-negative short-rod species such as Escherichia coli, Klebsiella pneumoniae, and Salmonella typhimurium being predominant. HPC values varied from 367 × 10⁴ to 1320 × 10⁴ CFU/mL, with EK2 (2505 × 10⁴ CFU/mL) and EK5 (1320 × 10⁴ CFU/mL) showing particularly high counts. The TCC values ranged from 1049 × 10⁴ to 4400 × 10⁴ CFU/mL, and the FCC values from 130 × 10⁴ to 800 × 10⁴ CFU/mL, all exceeding WHO limits (1.0 × 102 CFU/mL). Historical data show no improvement in water quality, emphasizing the need for individuals to treat water properly before consumption. The findings provide baseline data for local water authorities and serve as a wake-up call for adequate water treatment, storage interventions, and community education on water security. Additionally, this study offers a practical process for improving the quality of water stored in similar regions.

Ugwu J.C., Ubah C.B., Lawrence P., Edim M.M., N M.E., Enyike J.O., Edet H.O.

Glutathione remains one of the most efficient antioxidant compounds in living systems, and the biological abilities of hydrazides have been well documented in literature. This study highlights the phytochemical constituents of garlic and the separation of the bioactive benzoic acid, 4-chloro- 1-(4-methoxyphenyl) hydrazide (BA4C) using gas chromatography-mass spectroscopy (GC–MS) technique. Preliminary phytochemical screening reveals the presence of alkaloids, saponins, flavonoids, tannins, terpenoids, steroids and phenols. Computationally, compound BA4C was optimized using the B3LYP/aug-cc-PVDZ DFT method. Spectroscopic studies of the compound involved analysis of the vibrational FT-IR frequencies and the modes of vibrations. Frontier molecular orbitals analysis records an energy gap of 4.3391 eV; NBO studies reveal that the compound has strong perturbation energies of 246 kcal/mol and 269 kcal/mol among its intramolecular interactions such as $$\uppi$$ *C12 – C13 to $$\uppi$$ *C14 – C15 and $$\uppi$$ *C11 – C16 to $$\uppi$$ *C14 – C15, respectively. According to the visualization of non-covalent interactions, steric repulsions were observed at the core of the phenyl and benzene rings. However, other regions of the compound depict a significant balance of forces between steric repulsions and van der Waals forces. To significantly deduce the reducing power of compound BA4C, electrons were found to be highly localized at the methoxy and hydrazide moieties significantly implying their propensity to donate electrons to oxidized systems. Furthermore, ADMET analysis reveals that the compound has two hydrogen donors. Most significantly, the compound binds to NADPH dehydrogenase (5V4P) and glutathione reductase (1XAN) with binding energies of − 6.0 kcal/mol and − 8.0 kcal/mol showing considerable favourable binding feasibility as well as forming plural hydrogen bonds with the amino acid residues. Notably, BA4C was bonded at the active site of 1XAN, which implies the ability of the compound for the reduction of oxidized glutathione.