Emmanuel C . Nleonu | Federal Polytechnic Nekede Owerri, Nigeria (original) (raw)

Papers by Emmanuel C . Nleonu

Journal of Materials Engineering and Performance

Applied Research Journal of Science and Technology, Jun 30, 2023

The concentrations of ten heavy metals (As, B, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn) in surface sedimen... more The concentrations of ten heavy metals (As, B, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn) in surface sediments of Ulasi River, Okija in Anambra state Nigeria were assessed. Data from three sample stations that include; station A. Ubahuabuba, station B. below the bridge along Okija-Nnewi road, and station C. Onitsha-Owerri road were analysed. The result was obtained using ANOVA statistical analysis and there was a significant difference of 0.05%. The results obtained also revealed that the mean concentrations of the metals ranged from Arsenic 0.57 to 0.72mg/l, Boron 1.28 to 1.86mg/l, Cadmium 0.47 to 0.94mg/l, Chromium 0.67 to 0.96mg/l, Lead 0.94 to 1.30mg/l, Manganese 0.78 to 1.18, Fe 1.28 to 2.38mg/l, Cu 0.69 to 1.07mg/l, Zn 1.10 to 2.10mg/l and Nickel 1.10 to 1.36mg/l. When compared with the guidelines of the EPA for sediments, the results of the metals analysed were within the recommended threshold limits.

World Journal Of Advanced Research and Reviews, Nov 30, 2021

Density and viscosity of binary liquid mixtures of household kerosene (HHK) and premium motor spi... more Density and viscosity of binary liquid mixtures of household kerosene (HHK) and premium motor spirit (PMS) were determined over the entire range of mole fraction at 303K. Excess molar volume (V E), molar volume (Vm), Excess Viscosity (η E), Viscosity deviations (Δη) and excess Gibbs free energies of activation of viscous flow (ΔG E) were calculated. The results obtained shows that excess free energy of activation were all positive over the entire mole fraction. The viscosity deviation shows both negative and positive values. The positive V E obtained in this study shows increase in volume in the binary mixture. This work will help in effective monitoring, detection of adulterated kerosene and subsequent enforcement of severe penalty on such adulteration.

Journal of Physical Chemistry and Functional Materials

Journal of Physical Chemistry and Functional Materials, 2022

The adsorption and inhibition performance of thiourea and lithium ion on aluminium corrosion in 3... more The adsorption and inhibition performance of thiourea and lithium ion on aluminium corrosion in 3.5 % NaCl were investigated using gravimetric measurement, scanning electron microscope (SEM) analysis and quantum chemical computational techniques respectively. Gravimetric analysis revealed that thiourea has a good inhibitory efficacy of 82 % at 1 mM concentration of thiourea on the corrosion inhibition of aluminum under the conditions studied. Also, poor inhibitory effects were recorded with an increase in the concentration of inhibitor, and improvement in inhibition efficiency was observed with the addition of lithium ion. In addition, the effects of temperature (303-333 K) on corrosion inhibition was investigated. The findings showed that the effectiveness of the inhibition rises with temperature. The adsorption of thiourea molecules onto an aluminium surface followed the Temkin adsorption isotherm, while the mixed inhibitor of thiourea and lithium ion followed the Langmuir adsorption isotherm model. SEM results confirmed that the inhibition mechanism is due to the formation of a protective thin film on the aluminium surfaces that prevents corrosion. Quantum chemical calculations based on the density functional theory (DFT) revealed that the presence of sulphur and nitrogen in the structure of thiourea molecules is responsible for the strong inhibitory performance due to possible adsorption with Al atoms on the metal surface. The computed experimental and theoretical parameters in this investigation are in good agreement.

Zenodo (CERN European Organization for Nuclear Research), Mar 23, 2023

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Saudi journal of engineering and technology, Mar 12, 2022

In this research, Al 2 O 3 nanoparticles were successfully synthesized using facile chemical prec... more In this research, Al 2 O 3 nanoparticles were successfully synthesized using facile chemical precipitation method as a photocatalyst. The synthesized photo catalyst was characterized using scanning electron microscopy. The photocatalytic activity of the synthesized Al 2 O 3 was studied on the degradation of ciprofloxacin as a model pollutant in UV light irradiation by conductometry method. The experiments were carried out by varying contact time from 1-5 hours and catalyst load from 0.5-2.5g. The optimum catalyst dose and contact time were found to be 1g and 1 hour respectively for the drug degradation. The result exhibited photocatalysis activity. The photocatalytic activity can be attributed to higher absorption of UltraViolet light by the synthesized Al 2 O 3 that led to formation of a large number of reactive species. The Kinetics study of the photodegradation process was explained in terms of the modified Langmuir Hinshelwood model. The values of the kinetic rate constant (k) of the photodegradation were 8.0x10-3 min-1 and 5.0x10-2 min-1 in the absence and presence of the synthesized photocatalyst respectively.

Lubricants

The continuous search for eco-friendly corrosion inhibitors due to differences in corrosive media... more The continuous search for eco-friendly corrosion inhibitors due to differences in corrosive media remains an important point in corrosion control. The experimental studies on the corrosion inhibition of urea on mild steel in automotive gas oil (AGO) was conducted using gasometric techniques and scanning electron microscope (SEM). The theoretical approach on the density functional theory (DFT) on the urea molecule was carried out using Gaussian 09 software. The adsorption behavior of urea molecules on the surface of the mild steel was analyzed using Frumkin and Flory-Huggins adsorption isotherms models and Gibb’s free energy, respectively. The result of the experimental study shows a poor corrosion inhibitory effect of urea on mild steel in automobile gas oil (AGO) medium as the inhibition efficiency decreased from 69.30% in week 1 to 12% in week 11 at 200 ppm of inhibitor. The adsorption of urea on the mild steel surface obeys Frumkin’s adsorption isotherm model. Gibb’s free energy ...

Haya: The Saudi Journal of Life Sciences, 2022

Researchers in recent years are working on different approaches to the problem of bacteria resist... more Researchers in recent years are working on different approaches to the problem of bacteria resistant to antibiotics through drug modification. The synthesis of metal drug complexes are becoming more popular than their parent drugs because they possess modified pharmacological, toxicological and physiochemical properties. In this study, amoxicillin complexes of copper and zinc (II) ions were synthesized using standard method. The complexes were characterized for aqueous solubility, UV-visible spectral, acid stability, and thermal stability and in-vitro antimicrobial activities. The results of the physiochemical properties showed evidence of complex formation between the metals and the ligand. The acid and thermal stability of amoxicillin complexes showed high acid and thermal stability than its parent form. In-vitro antimicrobial activity of amoxicillin and its complexes form were studied against Staphylococcus aureus and Pseudomonas aeruginosa. The results revealed that Amoxicillin ...

Inhibitive effect of Lignin extract from Gmelina arborea bark on the corrosion of mild steel in 1... more Inhibitive effect of Lignin extract from Gmelina arborea bark on the corrosion of mild steel in 1M Hydrochloric Acid solution was studied by weight loss method with various periods of contact and temperature. The study revealed that the percentage inhibition efficiency increased with increase in inhibitor concentration. The temperature studies reflect that the adsorption of inhibitor on metal surface takes place via physisorption and through a spontaneous process. The inhibition at the metal surface was confirmed by X-ray diffraction examination.

World Journal of Advanced Research and Reviews

Density and viscosity of binary liquid mixtures of household kerosene (HHK) and premium motor spi... more Density and viscosity of binary liquid mixtures of household kerosene (HHK) and premium motor spirit (PMS) were determined over the entire range of mole fraction at 303K. Excess molar volume (VE), molar volume (Vm), Excess Viscosity (ηE), Viscosity deviations (Δη) and excess Gibbs free energies of activation of viscous flow (ΔGE) were calculated. The results obtained shows that excess free energy of activation were all positive over the entire mole fraction. The viscosity deviation shows both negative and positive values. The positive VE obtained in this study shows increase in volume in the binary mixture. This work will help in effective monitoring, detection of adulterated kerosene and subsequent enforcement of severe penalty on such adulteration.

Anthocleista grandiflora is commonly used traditionally as herbal medicine and has been documente... more Anthocleista grandiflora is commonly used traditionally as herbal
medicine and has been documented to have a broad range of therapeutic effects. This study was carried out to evaluate the effects of aqueous leaf extract of Anthocleista grandiflora on Serum Total Protein and Kidney Histology of Albino rats. A total of twenty (20) albino rats of both sexes were used for this study. The animals were divided into five (5) groups; A - E, with each group containing four (4) rats. Animals in group A were administered with distilled water and they served as control. Animals in group B – E were administered with different doses of the extract of Anthocleista grandiflora at dosage levels of 150mg/kg b.w., 300 mg/kg b.w, 450 mg/kg b.w and 600mg/kg b.w respectively. After twenty-one (21) consecutive days of treatment, all the rats were sacrificed. Blood samples were collected in sample bottles for the evaluation of serum total protein levels while the kidney samples were carefully excised and fixed in 4% formaldehyde for histological investigation. Biochemical results showed that at all the extract dose levels studied, the difference in serum total protein levels were not significant ( P>0.05) when compared with the control. From histological examinations, animals in group A were observed to have normal kidney cytoarchitectural features while those in groups B-E all showed moderate inflammatory response. It was therefore concluded that the aqueous leaf extracts ofAnthocleista grandiflora is safe for medicinal application especially at moderate dose levels.The continued use of the extract is therefore not discouraged.

The physico-chemical properties and functional surface group of Chrysophyllum albidum peel was st... more The physico-chemical properties and functional surface group of
Chrysophyllum albidum peel was studied using standard method and
Fourier Transformation Spectrocopy (FTIR) respectively to access its
potentials as a natural adsorbent in treatment of wastewater. The IR
spectra showed considerable functional groups such as –OH, -CH,
C=O and C-O while the physico-chemical analysis shown, moisture
(4.77%), pH (3.96), electrical conductivity (266μS), specific gravity
(0.5739), bulk density (0.6424g/ml), ash (5.19%), fiber (19.81%),
protein (3.75%), fat (14.35%) and carbohydrate (52.12%). The results
indicates that peel of C. albidum could be used as a low cost alternative
adsorbent to commercial adsorbent in the treatment of waste water.

Journal of Materials Engineering and Performance

Applied Research Journal of Science and Technology, Jun 30, 2023

World Journal Of Advanced Research and Reviews, Nov 30, 2021

Journal of Physical Chemistry and Functional Materials

Journal of Physical Chemistry and Functional Materials, 2022

Zenodo (CERN European Organization for Nuclear Research), Mar 23, 2023

Saudi journal of engineering and technology, Mar 12, 2022

Lubricants

Haya: The Saudi Journal of Life Sciences, 2022

World Journal of Advanced Research and Reviews

Density and viscosity of binary liquid mixtures of household kerosene (HHK) and premium motor spi... more Density and viscosity of binary liquid mixtures of household kerosene (HHK) and premium motor spirit (PMS) were determined over the entire range of mole fraction at 303K. Excess molar volume (VE), molar volume (Vm), Excess Viscosity (ηE), Viscosity deviations (Δη) and excess Gibbs free energies of activation of viscous flow (ΔGE) were calculated. The results obtained shows that excess free energy of activation were all positive over the entire mole fraction. The viscosity deviation shows both negative and positive values. The positive VE obtained in this study shows increase in volume in the binary mixture. This work will help in effective monitoring, detection of adulterated kerosene and subsequent enforcement of severe penalty on such adulteration.