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Open Access
Characterization of multiple log-periodic array antennas for surveillance systems using a novel array-factor
(Federal University of Technlogy, Owerri, 2023-11) Okoye, Arinze Christian
This research endeavors to comprehensively characterize Multiple Log-Periodic Array (MLPA) antennas, specifically in the context of surveillance systems, using a novel array factor. This array factor streamlines the numerical characterization of MLPA antennas, regardless of the number of elements involved. The study employs a rigorous analytical approach, incorporating the Magnetic Vector Potential (MVP) model and pattern multiplication approach through a top-down methodology. The MVP model was chosen for its auxiliary function, which greatly simplifies the analytical processes. In practical terms, experimental Multiple Log Periodic Array antennas were designed and evaluated for this study. The parameters of these antennas were numerically assessed in the far field using the newly developed Array Factor. MatLab R2010a software played a pivotal role in simulating various parameters of the Multiple Log-Periodic Array antennas, including Array Antenna patterns, Electric/Magnetic fields, Average Poynting Vector, Radiation Intensity, Radiated Power, Directivity, and Directive Gain. The results demonstrated that the array antennas had a Directivity/Gain of 15.68dB or 45.68dBm, at the operating frequency range of 1.350GHz to 2.690GHz. The collective array patterns generated by the MLPA antennas were in line with expectations, relying on the corresponding field of single element. Multiple Log-Periodic Array antennas expanded the function of Single Log-Periodic Array (SLPA) antennas by significantly enhancing radiation gain and signal coverage. Thus, the novel Array Factor accelerates the process of characterizing array antenna parameters, thereby alleviating the bottleneck in computing antenna losses. This marks a significant advancement in the field of antenna technology.
Open Access
Utilization of musa paradisiaca leaf extract-based inhibitor for corrosion protection of carbon steel in 3.5% Nacl
(Federal University of Technology, Owerri, Nigeria, 2025-05) Idema, Osuani Fyneface
The utilization of musa paradisiaca leaves (MPL) extract-based inhibitor on carbon steel protection in marine environment has been studied using gas chromatography mass spectroscopy (GC-MS), Fourier transform infrared spectroscopy (FT-IR), gravimetric method (GM), Atomic force microscopy (AFM), Contact angle measurement (Ө), potentiondynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), density functional theory (DFT) and molecular dynamics (MD) simulations. Firstly, the GCMS analysis showed the presence of compounds with heteroatoms in the MPL inhibitor. Likewise, the FT-IR analysis showed the presence of polar functional groups. The GM showed MPL extract-based inhibitor having optimum inhibition efficiency of 91% at a concentration of 100g/L and immersion time of 120 hours which led to a decrease in corrosion rate from 0.8817 mm/y to 0.0823 mm/y. Also, the weight loss experienced by the test specimen decreased from 0.0986g to 0.0091g. AFM morphology revealed thin film adhesion showing firm adsorption of Langmuir films on the metal/inhibitor interface, with root mean square roughness values for uninhibited and inhibited substrates 71.2722Rq and 33.6773Rq respectively. Likewise, contact angle measurement showed high contact angle of 152.42●with a hydrophobic metal/inhibitor interface for inhibited substrate hence not prone to corrosive species and low contact angle of 76.20● for the uninhibited substrate with hydrophilic surface which is prone to invasive corrosive species. The potentiodynamic polarization (PDP) via Tafel plots showed a cathodic slope capable of controlling both activation (oxidation) and diffusion (oxygen reduction) reactions. Also EIS via Nyquist, Bode plots and Phase angle showing high polarization resistance thereby reducing corrosion rate. Further, Density functional theory (DFT) analysis correlated the results by affirming the contributions of the isolated compounds of the MPL inhibitor molecule to the inhibition efficiency of 91%. In addition, MD results showed planer orientation of MPL inhibitor molecules over the surface of the substrate as such enhancing larger surface coverage, hence better inhibition effectiveness. Also, the high adsorption energy of -184.954cal/kJ is indicative of chemisorption. Radial distribution function (RDF) showed presence of short bond lengths of between 2.97-3.49 atom thick, confirming the presence of strong covalent bonding. Test of adsorption isotherms reveal conformance of the Langmuir model
Open Access
Environmental air pollutants as risk factors in the occurrence of respiratory conditions in some selected LGAs of Bayelsa State Senatorial Zones
(Federal University of Technology, Owerri, 2025-05) Ekiyor, Christopher Peres
Ambient (outdoor) air pollution is a major cause of disease and death globally. Poor ambient air quality occurs when pollutants reach high enough concentrations to affect human health and the environment. Long-term exposure to air pollution reduces life expectancy, as an after effect of respiratory diseases such as lung cancer which is associated with exposure to air pollution. The present study was primarily aimed at establishing the level of risk of respiratory conditions that are contributed by the various environmental air pollutants which affect the residents of Bayelsa State. The study was designed as a population-based survey study performed in Bayelsa State Nigeria. The study involved measurement of some targeted air pollutants and their ambient concentrations which were compared with the WHO‘s permissible standards and the Federal Ministry of Environment recommended limit. In addition, a questionnaire was used to assess 428 adult residents of Bayelsa State on the level of knowledge of the respondents about respiratory conditions, specifically on causes, prevention and control. The respondents were recruited from several communities across different local government areas in two senatorial zones in the State representing (Bayelsa Central and Bayelsa West). The two zones were purposively selected to represent the two types of environments in Bayelsa State (fresh water and salt water activities). Further, purposive sampling technique was also used to purposively select LGAs the fall within the fresh water and salt water activities in each of the two study zones. The mean ambient air quality level of the study area was compared with the WHO permissible limit and also with Ministry of Environment recommended standard for each pollutant using t-test method. Also, t-test was used to compare the mean ambient air quality level between Bayelsa West and Bayelsa Central while ANOVA test was used to compare the mean ambient air quality level across the study LGAs, The respiratory condition of the study participants was measured using PEFR and the outcome was classified as normal or poor respiratory conditions. The relationship between exposure to air pollutants and respiratory conditions were assessed in a logistic regression method. The result shows that the knowledge was high on some of the common respiratory symptoms such as persistent cough (93.3%), wheezing (92.8%) and Fatigue and weakness (72.7%). Just 53.7% (230 out of 428), showed good knowledge of respiratory conditions rom ambient air pollutants within their environment. The mean ambient level was high and exceeded WHO and FMOEnv permissible limit for all the pollutants SO2 (78.53 ± 22.32 μg/m3), NO2, (62.59 ± 17.78), C0 (8.47 ± 4.66), NH (0.37 ± 0.23), PM 2.5 (51.58 ± 17.17) and PM 10 (170.19 ± 44.42).Southern Ijaw contained the highest level of SO2 and NH (0.94μg/m3), The NO2 was found highest in Yenagoa (152.1 μg/m3), while CO also high in Ekeremor LGA (23.4μg/m3). The average PEFR was 451.6 ± 77.6 l/min for the study group. The mean PEFR was significantly lower in Bayelsa West (429.8 ± 73.4 l/min) than in Bayelsa Central (473.3 ± 87.5 l/min) (p < 0.0001). Common respiratory symptoms in the area were wheezing (25.7%), pneumonia (18.1%), 54 (11.6% for asthma (11.6%), COPD (11%), bronchitis (5.1%) and others. Association was found between exposure to air pollution and poor respiratory conditions (P <0.000). The study concluded that the study area is well polluted and required urgent attention to enforcement of protective measures against ambient air pollutants.
Open Access
Isolation, characterization and radical-scavenging potentials of bioactive components of combretum dolichopentalum leaves
(Federal University of Technology, Owerri, 2016-04) Ujowundu, Favour Ntite
The present study isolated, identified and characterized the bioactive components of Combretum dolichopentalum leaves and determined the antioxidant potentials of the extracts of the leaves on some biochemical and physiological parameters. Biochemical methods such as ion exchange chromatography, column chromatography, thin layer chromatography, gas chromatography (GC), gas chromatography-mass spectrometry (GC-MS), spectrophotometric analyses, atomic absorption spectrometry and Fourier transform infra red (IR) were used. Preliminary phytochemical analyses showed the presence of flavonoids, alkaloids, saponins, tannins, oxalate and phytate. Further screening show the presence of flavonoids: kaempferol, luteolin, isorhamnetin and apigenin; alkaloids: akuamidine, undulantine, powelline and their hydroxylated compounds, voacangine and buphranidine; saponins: hicogenin, sapogenin, tribuloin and tannic acids. The use of GC-MS aided the identification of organic acids: (heptedecanoic acid), organic esters (ethyl octadecanoate), ketones (6,10-dimethyl-2- undecanone), alcohols (3,7,11,15-tetramethyl-2-hexadecen-1-ol) and phenol derivatives (Phenol-2,6-bis (1,1-dimethyl)-4 -methyl, methyl carbamate). Also, the eluates obtained from column and thin layer chromatography were analysed with IR and phenol-2,6-bis (1,1- dimethyl)-4-methyl, methyl carbamate, nitrocyclohexane, fluorodecane and others were identified. Proximate analysis showed the presence of carbohydrates, proteins, lipids, sodium, potassium, phosphorus, vitamins A, E and B-vitamins. Amino acid profile using the technicon sequential multi-sample amino acid analyser (TSM) showed the presence of essential and non essential amino acids. The effects of isolates such as flavonoids, saponins, alkaloids and tannins were determined for in vitro hydrogen peroxide scavenging ability. The effects of the extract in comparison with a standard drug (silymarin) on animal organ/tissue functions and on serum concentrations of electrolytes, beneficial transition minerals, lipids, antioxidants and markers of lipid peroxidation were determined. The effects of the crude extract in comparison with standard plant antioxidant (quercetin) and butylated hydroxyl toluene (BHT), for in vitro scavenging potentials showed dose dependent scavenging potentials on nitric oxide, hydroxyl radical, H2O2 induced lipid peroxidation and reducing power. Intoxication with CCl4 after pre-treatment with the ethanol extract and crude flavonoid, saponin, alkaloid and tannin fractions indicated hepatoprotective and antinephrotoxic potentials except saponins isolate which showed a significant (P˂0.05) adverse effect as indicated by some biochemical and physiological parameters. Flavonoid and alkaloid extracts are the major fractions that elicited biochemical and physiological benefits in CCl4 intoxication. The in vitro and in vivo radical scavenging properties of extracts of C. dolichopentalum make a promising drug with strong antioxidant potentials and inhibitory against Escherichia coli and Salmonella typhi.The present study isolated and characterized the phytochemicals in C. dolichopentalum leaves which could be further exploited for the treatment of oxidative stress and microbial induced disorders and diseases especially in light
Open Access
Effects of some indigenous plant extracts on carbon tetrachloride-induced hepatic fibrosis in male wistar rats
(Federal University of Technology, Owerri, 2017-11) Ukairo, Doris Ifeyinwa
Plant-derived drugs and antioxidants are widely used in the management of chronic liver diseases and cirrhosis. Methanol extracts of raw (R) and cooked (C) samples of Sphenostylis stenocarpa (SS), Chromolaena odorata (CO), Buccholzia coriacea (BC) and Monodora myristica (MM), at doses of 250 mg and 500 mg per kilogram body weight of male Wistar rats were evaluated for their effects on carbon tetrachloride (CCl4)-induced hepatic fibrosis. One hundred and sixty (160) rats (155 ± 20 g) were distributed into twenty groups of eight rats each; representing normal control, olive oil control, negative control, positive control (silymarin) and various groups treated with raw and cooked extracts of the samples at the stated doses (RSS250, RSS500, CSS250, CSS500, RCO250, CCO250, etc.). The extract-treated groups were pre-treated with their respective extracts twice a week for four weeks before the introduction of toxicant. All the groups except normal and olive oil controls were intraperitoneally injected with 1 mg/kg of CCl4/olive oil (1:1 v/v) mixture twice a week for four weeks with continued extract-treatment. Liver and kidney damage were assessed using various biochemical parameters, such as the enzymes; alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phospatase (ALP), lactate dehydrogenase (LDH) activities, as well as bilirubin, urea, creatinine, electrolytes and malondialdehyde (MDA) concentrations. In addition, CCl4-induced pathological changes were evaluated by histopathological studies and the expression of collagen as evidence of induced fibrosis confirmed by immunohistochemistry. Treatment with methanol extracts of SS, BC and MM especially at low concentrations significantly (P<0.05) ameliorated the effects of CCl4 intoxication by reducing hepatic enzymes and LDH activities and as well increased other parameters. The effects of the extracts were attributed to the phytochemical compositions of the plants. The findings provided evidence to show that methanol extracts of SS, BC and MM at low concentrations possessed antifibrotic and hepatoprotective properties against CCl4-induced liver injury in male Wistar rats through their antioxidant and anti-inflammatory activities.
Open Access
Physico-mechanical properties of natural rubber filled with treated groundnut shell powder for shoe sole production
(Federal University of Technology, Owerri, 2016-03) Ayo, Mark Dada
Physico-Mechanical properties of natural rubber filled with chemically modified groundnut shells were studied. Natural rubber composites were prepared using modified fillers at varying concentrations of sodium hydroxide (NaOH) Solution and acetylating solutions respectively. The processing conditions, mechanical properties and sorption characteristics of these composites were analyzed. The cure characteristics of the compounded rubber were determined using Mosanto Rheometer (model MDR - 2000). The maximum torque and crosslinking density increases with increase in concentration of the mercerizing and acetylating agent. The fibre reinforcing efficiency of the chemically treated composites were compared with that of the untreated composite. Composites containing chemically treated fillers were found to posses improved tensile properties(from 18.30 to 31.50MPa for acetylated composites and 18.30 -28.00MPa for mercerized fillers), hardness (48 to 65 IRHD for acetylated filler and 48 to 58 for mercerized fillers) and abrasion resistance (from 31.55 t0 42.50% for acetylated filler and 31.5 to 39.30 for mercerized filler). These properties increases with increase in mercerizing and acetylating agent up to 20% concentration and starts decreasing. At higher concentration, the fibre is destroyed hence reduction in properties. These results were in agreement with empirical analysis. The sorption properties of the composite also decrease with the concentration of the mercerizing and acetylating agent. The improved properties observed were as a result of the increase in affinity between the rubber matrix and the chemically treated groundnut shell fillers. From this research work, it is recommended that chemically treated groundnut shell powder, particularly at 20% concentration can be employed for articles such as shoe soles, footmats and hoses that require less stress during service life.
Open Access
Production and characterisation of biodegradable biofilm from plantain peel, eggshell and cassava starch
(Federal University of Technology, Owerri, 2025-01) Okeyahweh, Chinyere Simcha
Biodegradable films are made from natural polymeric materials such as starch, vegetable oil, cellulose, lignin, and also materials derived from animals such as proteins and lipids. They are easily degraded by microbes, and the degradation process does not take a long time. The present study investigated the use of ripe plantain peels as a source material for producing biodegradable biofilms; using powdered ripe plantain peels, eggshell powder, acetic acid – vinegar - and cassava starch produced in the study. The biofilms synthesized were plantain peel-based biodegradable biofilms: P-BF, and non-plantain peel biofilm: N-BF, which served as control. The synthesized biofilms were characterized using FTIR, GC-MS, morphology test, water absorption property, biodegradation test, solubility test and swelling test and mechanical test; ultimate tensile test, flexural, hardness test, % elongation and thermo gravimetric analysis. The results of the FTIR analysis of the P-BF and N-BF showed 8 functional groups: ether, ethene, amine, carboxylic acid, nitriles, methylene, cyclic ester, primary, secondary and tertiary alcohols common to hydrocarbons. The results of the biodegradability test showed that both P-BF and NBF biofilms degraded completely on the 12th day. The results of the thermo gravimetric analysis showed that the P-BF biofilm decomposed at the temperature of 29.920C-500°C leaving 44.19% residue and compared to the N-BF biofilm which decomposed at the temperature of 22.170C - 500°C leaving 11.9% residue. This implies that, P-BF matrices, started degrading at 130 °C, while N-PF fibers start degrading at 139 °C. Therefore, the processing temperature for ripe plantain peels was set to below 137 °C to avoid unwanted degradation of the material. Furthermore, the results of the mechanical tests for P-BF showed ultimate tensile test, flexural test, hardness test, and % elongation; 2.87±0.02 Nmm^2, 0.41±0.01 Nmm^2, 22.00±1.78 Nmm^2 and 6.29±0.01 Nmm^2 respectively. while, the result of the mechanical test of N-BF showed ultimate tensile test, flexural test, hardness test and % elongation; 5.45±0.02 Nmm^2, 0.41±0.01 Nmm^2, 49.00±1.78 Nmm^2 and 13.85±0.03 Nmm^2 respectively. The solubility test of P-BF showed partial solubility in acetone, sulfuric acid and ethyl alcohol while the N-BF were completely insoluble in ethyl alcohol but partially soluble in sulfuric acid and acetone. The result showed that the biofilm was not completely soluble. The results of the swelling test for P-BF showed a mean of 0.04±0.00 when soaked in chloroform; and N-BF; 0.02±0.00. When soaked in methanol, P-BF showed a mean of 0.10±0.00 while N-BF showed a mean of 0.10± 0.01.The water absorption analysis showed that P-BF had 31% engorgement while N-PF had 46 % engorgement. The P-BF have high affinity for water due to the hydrophilic nature of the cellulosic fibers in the plantain peel as well as the water absorbing property of glycerol. The biodegradability test showed the plantain based biofilm degraded completely with no toxic effect on the soil implying that the biomass may serve as a potential material for production of an ecofriendly biofilm with good mechanical properties. The study showed that biodegradable biofilms can be synthesized from plantain peel at 3 % plantain peel, 1 % acetic acid, 3 % cassava starch, 1 % eggshell and 3 % glycerol. In conclusion, the study reported that powdered plantain peel-based biofilm with good mechanical properties can be produced.
Open Access
Impacts of anthropogenic activities on soil and water quality of Kolo-Creek, Niger Delta, Nigeria
(Federal University of Technology, Owerri, 2024-11) Ajayi, Olumide
This study evaluates the impact of anthropogenic activities on soil and water resources in Kolo Creek, Niger Delta, Nigeria. Hydrocarbon exploration, illegal refining, and waste disposal have significantly disrupted environmental balance, necessitating site-specific assessments and pollution evaluation for effective mitigation. Soil, surface water, and groundwater samples were collected from ten georeferenced locations, with groundwater extracted from six meters’ depth. Heavy metals (Fe²⁺, Pb²⁺, Cd²⁺, Cr³⁺, Cu²⁺, Zn²⁺) were analyzed using atomic absorption spectrophotometry (AAS), while total petroleum hydrocarbons (TPH), polycyclic aromatic hydrocarbons (PAH), and benzene, toluene, ethylbenzene, and xylene (BTEX) were measured via gas chromatography-flame ionization detection (GC-FID). Geotechnical properties (Atterberg limits, porosity, permeability) were assessed per ASTM (1975) and British Standards (BS 1377). Results indicate that apart from low pH (acidic conditions), most surface and groundwater parameters comply with WHO drinking water standards, except Fe²⁺ (125.82 mg/L), Hg²⁺ (1.05 mg/L), TPH, PAH, and BTEX, which exceed permissible limits. Multivariate statistical analysis identified six (6) principal components, while hierarchical cluster analysis (HCA) revealed two distinct pollution sources. Correlation analysis confirmed strong interrelations among contaminants, implying a common pollution origin for soil, surface water, and groundwater. Contamination factor analysis classifies Fe²⁺ (9.1) as highly contaminated in surface water, while Ca²⁺ (2.88) and Fe²⁺ (125.82) in groundwater indicate moderate to extreme contamination. Water quality index (WQI) results confirm that 100% of water samples are unfit for drinking, irrigation, or industrial use. Additionally, pollution index of groundwater (PIG >2.5) suggests severe contamination. However, irrigation suitability tests indicate that surface water meets agricultural standards based on Sodium Absorption Ratio (SAR) values. Heavy metal contamination in soil, particularly Fe²⁺ (18.97), Al³⁺ (1.02), Hg²⁺ (1.05), and Cd²⁺ (1.28), poses significant environmental risks. Geo-accumulation index (Igeo) classifies soil as moderately polluted by Cd²⁺ and heavily polluted by Fe²⁺ and Hg²⁺. Furthermore, carcinogenic risk (CR) assessment shows that average CR values exceed 10⁻⁶ (>10⁻⁶) for both adults and children, indicating a potential cancer risk. Alarmingly, children face a threefold higher cancer risk than adults. Hydrocarbon contamination has altered soil geotechnical properties, evidenced by lower permeability and plasticity index (5–9%), classifying it as low-plastic, partially cohesive silt. However, this modification suggests that affected soils could be reused for engineering applications.
Open Access
Modelling of combustion in natural draft burners for improved performance
(Federal University of Technology, Owerri, 2024-02) Nwoye, Favour Chukwunonso
Combustion in natural draft burners involves the passive induction of atmospheric air into the burner mixer when a fuel jet flows through a venturi. The interaction of the fuel jet and air stream at different velocities causes shear and Kelvin Helmholtz instability that grows into turbulence and molecular mixing of both species. Modeling of flow and combustion process in natural draft burners for improved performance are presented. It involves the response of the flow to changes in the axial coordinate of the nozzle and passive alteration of the flow conditions upstream of the origin. The alteration was by varying the nozzle streamlines and installing a trip ring at the nozzle exit. The Reynolds Averaged Navier-Stokes (RANS) equation was used to model the flow physics; the turbulence modelling was done with the Reynolds Stress Model (RSM), while the standard wall function captured the near wall flow behaviour. The implementation was undertaken using ANSYS Fluent 18.1, and the model was validated with Binder and Kian experimental work. A low-fidelity model developed and implemented with a MATLAB script offered a cheap and quick alternative for the parametric investigation of jet flow and combustion processes. The flow parameters of interest are the velocity decay, pressure gradient, turbulence, ambient air entrainment, and its mixing with the fuel jet stream. The ratio of the axial distance between the nozzle exit and throat 𝑙𝑇𝑁 and the throat diameter 𝑑𝑇, 𝑙𝑇𝑁 𝑑𝑇 defined the position of the nozzle from the throat. At 𝑙𝑇𝑁 𝑑𝑇=2.0 and 𝑙𝑇𝑁 𝑑𝑇 = 0.5 as reference, the increase in the velocity decay rate and the entrainment values were over 8% and 7%, respectively. These shows that when the nozzle was closer to the air inlet, velocity decay was faster, the entrainment was higher, and the mixing was better. The modification with the trip ring involved the installation of 0.5mm thick rings at the nozzle exit. The installed ring diameters were 4.9, 4.7, and 4.5mm, concentric with the nozzle trailing edge. The wake formed behind the trip ring interacted with the streamwise vortices and suppressed the near-stream turbulence. Flow modification with a 4.9mm ring increased the turbulence at the ejector outlet by over 26.6%. The final entrainment value was 16.7% higher, but the drop in the decay rate was 9.6%. The 4.9mm ring performed best because of the delayed flow separation and reduced pressure drag. Four different nozzle streamlines (PN1, PN2, PN3, and PN4) produced by straight lines and sine function combinations yielded different streamwise sectional area. With PN4 as the reference nozzle, the decay rate, entrainment and the maximum turbulence intensity increased by approximately 1.7, 8 𝑎𝑛𝑑 16%, respectively, in the PN3 nozzle, which has the smallest streamwise sectional area and the highest momentum difference between the streams. The relationship between the near stream decay rate and the streamwise sectional area was linear. Therefore, passive modification of the jet structure improved the burner performance substantially. Pressure drag formed behind the ring adversely affected performance. An optimized streamlined ring profile can delay flow separation and reduce pressure drag, thus recommended for further investigation
Open Access
Development and performance evaluation of a diurnal passive radiative cooling system for application in buildings
(Federal University of Technology, Owerri, 2024-02) Okoro, Humphery Ogbonnia
Space cooling for thermal comfort consumes significant amount of energy, and this has continued to be a major global challenge. However, space cooling needs are increasing in the tropics due to increase in energy intensive lifestyles, population increases, and incessant increases in ambient temperature. Global warming and climate change issues associated with convectional energy usage are increasingly informing investments in sustainable and clean energy systems. Accordingly, the development and performance evaluation of a diurnal passive radiative cooling system for space cooling application in buildings are hereby presented. Two diurnal passive radiative coolers using dual-layer mesoporous polyethylene aerogel and ultra-white barium sulphate on silver substrates as selective reflective surfaces were designed and fabricated. This test rig is a rectangular box with two compartments in which the coolers are installed for investigation. The top of the test rig is covered with a low density polyethylene windscreen, which is transparent to radiation in all wavelengths. Thermocouples are inserted underneath and outside the coolers to record the temperatures of the coolers and the ambient respectively. Extensive field investigations were conducted with these photonic coolers under direct solar irradiance in three different locations under Nigerian climatic conditions, namely, Abuja, Afikpo, and Owerri. The experimental results for a 24- hour test show that the diurnal passive radiative system achieved significant cooling performances with sub-ambient temperatures of about 3-5, 3-6, and 2-6 oC during the daytime and 1-2, 0-1, and 0.5-2 oC at night, for Abuja, Afikpo, and Owerri respectively for Mesoporous polyethylene aerogel cooler. For the barium sulphate cooler, sub-ambient temperatures of 2-3, 1.5-3.5, and 1-3.5oC during the daytime and 0-1.5, 0-0.5, and 0-1 oC at night were reported. Average cooling powers of 108.84, 84.99, and 101.06W/m2 were recorded in Abuja, Afikpo, and Owerri respectively with the mesoporous polyethylene Aerogel, while 120.29, 89.81, and 106.74W/m2 were recorded with the barium sulphate in Abuja, Afikpo, and Owerri, respectively, during the investigation. Also, a theoretical model was developed and used to numerically predict the thermal performances of the coolers in six locations, namely, Abuja, Yola, Afikpo, Ado-Ekiti, Kaduna, Owerri, and Warri, representing the different geopolitical zones in Nigeria. The model equations were discretized using finite element numerical scheme for ease of implementation on a digital computer. The system behaviour was simulated with the developed model using a code written with FlexPDE Finite Element Model Builder and Numerical Solver Version 7.12. The numerical results obtained from the models were compared with experimental results and other similar data from the literature. The deviations of the model and experimental temperatures were recorded as ±2.73oC for Mesoporous polyethylene aerogel and ±1.81oC for barium sulphate. Thus, for the numerical performance evaluation, the model results closely matched experimental results with total standard uncertainties of 0.64 for Mesoporous polyethylene aerogel and 0.37 for barium sulphate. These deviations are less than 1, which is a necessary condition for model accuracy. Sensitivity analyses show that the optimal performance parameters are 15mm, 30o , and 5, for the cooler thickness, orientation and number of windscreens, respectively. Therefore, further material development, extended field investigation, and possible deployment of passive radiative cooling system for use in residential buildings are recommended.
Open Access
Optimization of biogas production from some agrowastes in a batch system bioreactor
(Federal University of Technology, Owerri, 2023-12) Nwaneri, Chioma Blessing
This study was carried out to co-digest and optimize biogas production from some agrowastes in a batch system bioreactor. Six substrates; Palm oil mill effluent (POME), Pig dung, Cow dung, Poultry manure, Cassava peels, and Cabbage waste were used in the investigation. The proximate analysis of each substrate and the microbiological analysis of the co-digested subsrates were obtained. The substrates were anaerobically digested as single substrate and codigested with each other to improve the nutritional composition and biodegradability. Laboratory scale 10L capacity bioreactors were used to carry out the batch system anaerobic digestion of the different substrates for substrate ratios of 1:1, 2:1, 3:1, pH range of 6.8-8.0 and a hydraulic retention time of 45days. Then Box Behnken’s design of response surface methodology of three factors; substrate ratio, pH, and hydraulic retention time at three levels; 1:1, 2:1, 3:1(substrate ratios), 5, 7, 9 (pH) and 15days, 30days and 45days (hydraulic retention time) were used in the optimization, considering the substrate with the highest biogas yield.Sodium hydroxide (NaOH) and hydrochloric acid (HCl) were used for adjusting the pH values to the required range. Compositional gas analysis of biogas produced was carried out using Gas Chromatography. The proximate analysis of the substrates showed that the C:N ratios of POME, pig dung, cow dung, poultry manure, cassava peels and cabbage waste were 10.13:1, 5.84:1, 17.50:1, 14.24:1, 46:1 and 16.90:1 respectively. It was also observed that none of the substrates had an optimium C: N ratio hence there was need for co-digestion of the substrates to improve biogas yield. The result also showed that co-digestion of cassava peels with cow dung had the highest biogas yield, flamed on the second day with bright blue flame and had the highest percentage methane content of 78.05%. The results showed the presence of these bacterial isolates; Escherichia coli, Enterobacter sp, Salmonella sp, Shigella sp, Bacillus sp, Pseudomonas sp, Staphylococcus sp, Micrococcus sp and fungal isolates were Saccharomyces sp, Aspergillus sp, Rhizopus sp, Penicillium sp, Geotrichum sp. The optimization result showed that the substrate ratio of 3:1, pH 7 and 15days hydraulic retention time had the highest biogas yield, highest methane content of 79.143% and flamed on the second day of the anaerobic digestion. Statistical analysis of the results showed significant difference (p ≤ 0.05) in biogas production in all the treatments. Further anaerobic digestion of cassava peels with cow dung using the predicted values from the computer aided Box Behnken design response surface methodology analysis showed the same trend with the experimental data. In terms of sustainable biogas production, the outstanding result showed by CP/CD 3:1 at pH 7 proves that the test parameter can be adopted for domestic biogas production.
Open Access
Tree species diversity, biomass production and carbon stock of three forest management types in Benue State, Nigeria
(Federal University of Technology, Owerri, 2025) Dau, Henry Japheth
Carbon stocks can be conserved or increased by the sustainable management of existing forest types. However, anthropogenic activities and poor forest management can adversely affect biomass production and carbon storage. Published information on biomass and carbon storage potentials of different forest management types is scanty, especially in the study area. To this end, this study assessed the tree species diversity, soil properties, volume estimation, biomass and carbon storage of three forest management types (Community Forest Area (CFA), Forest Reserve (FR), and Sacred Grove (SG)) in Benue State, Nigeria. A nested plot design was adopted for data collection. Each nested plot comprises 35 m x 35 m, 25 m x 25 m, 7 m x 7 m, and 1 m x 1 m square plots. The 35 m x 35 m area was the main plot within which all trees with a Dbh of 40 cm and above were measured. The 25 m x 25 m subplot was laid within the main plot, and all trees with Dbh between 20 cm and 40 cm were measured. Within each subplot, a sub-subplot of 7 m x 7 m was laid for the enumeration of trees with a Dbh range of 5 m to 20 cm. A quadrat of 2 m x 2m was laid within the 7 x 7 m plots to assess low vegetation with a diameter <5 cm. A square frame of 1 m x 1m was laid to assess all litter. An experienced forest-type management taxonomist identified all live tree species. Tree growth variables (diameters at the base, breast height, middle, and top of the tree and tree total heights) were measured on all live trees, standing dead and lying dead trees in all plots. An indirect method of biomass estimation was used in this study. Tree core samples were collected at tree breast height (1.3m) using an increment borer. Data were analyzed using descriptive (mean, frequencies, and standard deviations) and inferential (analysis of variance, T-test and Pearson correlation) statistics. A cumulative total of 1,881 individual trees were enumerated in the study area, with 749, 621, and 511 individual trees found under FR, SG, and CFA, respectively. A total of 73 tree species in 35 families were assessed in the study area, out of which CFA had 38 species from 25 families, FR had 28 species from 16 families, and SG had 35 species from 24 families. Most of the tree species were indigenous, with few exotic species (Gmelina arborea and Tectona grandis). Khaya senegalensis and Gmelina arborea were present across the three forest management types, with varied frequency of occurrence. The Family Importance Value Index (FIV) in CFA and SG indicated higher family density in these forest management types than in FR. A few families (Caesalpinioideae, Euphorbiaceae, Moraceae, and Fabaceae) were important across the forest management types. Malvaceae, Verbenaceae and Fabaceae were the most important families in CFA, FR and SG, respectively. Ty. The Shannon-Wiener index of 3.00, 2.11 and 2.97 were recorded under CFA, SG and FR, respectively and differed significantly. The Margalef richness index was highest (6.01) under CFA and lowest (4.11) under the FR. The highest evenness value of 0.55 was recorded under SG, and the lowest value (0.29) was under FR, indicating a high disparity in tree species richness. Gmelina arborea, Sterculia
Open Access
Management of insect pests of bambara groundnut (Viga subterranean (L.) Verdcourt.) with some plant oils in rain forest zone of Owerri, Imo State
(Federal University of Technology, Owerri, 2023-03) Nwamkpa, Akachukwu Pius
Studies were conducted from March- June for the early season and August- November for the late season of 2016 and repeated same time in 2017 at the Postgraduate Teaching and Research Farm of the Department of Crop Science and Technology, Federal university of Technology, Owerri, Nigeria. A total of 60 treatment combinations were laid out in a 5 x 4 factorial arrangement with three replications fitted into a randomized complete block design (RCBD) for the field trials to evaluate the efficacy of the plant oils (Bush tea Hyptis suaveolens. (HEO), Stool wood Alstonia boonei. (AEO), Jathropha tanjorensis (JEO,) mixed plant oils from Jathropha, Bush tea and Stool wood bark (J+A+HEO) against field insect pests of Bambara groundnut. Population dynamics of insect pests of Bambara groundnut under control measures with plant oils were also studied. The oils were tested at four rates (0.00, 2.00, 4.00 and 6.00 ml/100 ml of H2O per plot) and Cypermethrin 10EC at the rates of (0.00, 0.20, 0.40 and 0.60 ml/100 ml of water per plot). Some field insect pests including variegated grasshopper (Zonocerus variegatus), Flea beetle (Podagrica uniformis and Podagrica sjostedti), Leaf miner (Aproaerima modicella) and Aphids (Aphids crassivora) inflicted damage to the leaves of Bambara groundnut. The treatment materials provided effective protection against insect pests of Bambara groundnut at different levels when compared to the unsprayed plots. The unsprayed plots recorded highest number of damaged leaves at the vegetative phase, flowering and podding phase followed by the lowest application rates, while the highest application rates recorded the least damaged leaves by insect pests in 2016 and 2017 early and late planting seasons. The results on yield showed that the plant oils were able to reduce the population of insects which resulted in an increase in the 100 Seed and Pod weight (g), Seed and Pod yield (kg/ha, though they were not significantly different (P>0.05).
Open Access
Analysis of response capacity of rural households to selected poverty intervention programmes in Imo State, Nigeria
(Federal University of Technology, Owerri, 2016-11) Ajaero, Joseph Onyewuchi
This study analysed the response capacity of rural farmers to National Fadama Development Programme (NFDP) and National Special Programme for Food Security (NSPFS) in Imo State, Nigeria. The specific objectives were to; categorize and describe response capacity of rural farmers, assess the level of knowledge of rural farmers’ to the rural poverty intervention programmes, determine the relationship between behavioural process and response capacity, determine factors that affect positive response to rural poverty intervention programmes, ascertain the rural farmers’ perception of agricultural extension effectiveness on positive response to rural poverty intervention and identify the perceived constraints to desirable response to poverty intervention programmes in the study area. Data were collected through the use of standardized questionnaire. Descriptive statistics (frequency distribution, mean score and percentages) and inferential statistics (multinomial logit regression, Chi-square and Univariate analyses) were used to analyse the data generated. The mean age was 50.7 years. Majority (57.9%) of the rural households in the study area were male with mean household size of 6 persons. The results further showed that majority (86.5%) of the rural farmers were engaged in crop production. The mean net annual farm income was N97041.63. Majority (90.6%) were members of social organisation especially cooperative societies (65.1%). A total of 97.4 percent had one form of formal education or the other. Extension agents (71.7%) were identified as their major source of agricultural information. The study found that majority (58.3%) of the rural farmers had high level of knowledge about NFDP while only 31.7% had high knowledge level about NSPFS. Majority (64%) of the rural farmers perceived extension service as not effective in activities in rural poverty intervention programme. The study also revealed that behavioural process has a positive and significant effect on response capacity at p0.05 critical level with a regression coefficient of 0.693 and R 2 of 0.894. Majority (65.7%) of the rural farmers in the study area fell within the desirable response capacity, which is a sociological prerequisite for participation in rural poverty intervention programme. The multinomial logit regression results revealed that probability of being in the desirable response category increases with net annual income (4.055) and farmers’ self esteem (0.373) while sex (4.645), level of education (9.300), extension effectiveness (38.569), number of information sources (11.772) and distance to LGA headquarters (11.111) each decreases the probability of being in desirable response category to rural poverty intervention relative to the reference category. The constraints militating against positive response to NFDP and NSPFS poverty intervention programmes included institutional bottlenecks of the programmes (M = 3.32), lack of access to credit (3.19), lack of capital (M = 3.00), stringent requirements for qualification to participate in the programmes (M = 3.16), lack of awareness of NSPFS (M = 2.98) and lack of awareness of NFDP (M = 2.56). The study recommends that government should reposition extension service to be effective in services delivery to targeted beneficiaries in future poverty intervention programmes. Also the existing public agricultural extension service, Imo State Agricultural Development Programme (IMADP) should work in synergy with programme-donor agencies in order to carry out good sensitization campaigns at the inception of any rural poverty programme to create awareness and lay the foundation for desirable response required for the programme success.
Open Access
Analysis of thick anisotropic plate through exact approach using third order shear deformation theory
(Federal University of Technology, Owerri, 2021-09) Ozioko, Hyginus Obinna
This work presents the Analysis of Thick Anisotropic Plate through Exact Approach using Third Order Shear Deformation Theory. Total potential energy was formed based on the refined plate theory assumptions. Displacement field, kinematic relations, constitutive relations and stress displacement relations were derived from the deformed section of a thick rectangular anisotropic plate. Strain energy was formed by substituting the kinematic relations and stress-displacement relations into the universal strain energy equation. By the addition of the external work to the strain energy equation, total potential energy functional for the analysis of thick anisotropic rectangular plate was obtained. The total potential energy functional was minimized by differentiating it with respect to the changes in out-plane deflection, δw, shear deformation rotation in x direction, δ ௫ , and shear deformation rotation in y direction, δ௬ . This yielded the governing equation and two compatibility equations of thick anisotropic rectangular plate. A third order polynomial shear deformation was employed in the governing and compatibility equations to obtain the displacement functions (deflection, w, shear deformation rotation in x direction,  ௫ , and shear deformation rotation in y direction, ௬ ). These displacement functions (w,  ௫ , ௬) obtained satisfied the specified boundary conditions and it gave the unique displacement functions for each of the twelve plate boundary conditions SSSS, CCCC, CSSS, CCSS, CSCS, CCCS, SSFS, CCFC, SCFS, CCFS and SCFC solved. The stiffness coefficients (ܭଵ, ܭଶ, ܭଷ, ܭସ, ܭହ, ܭ଺, ܭ଻, ܭ଼ (were calculated for each of the twelve plate boundary conditions. The formulas for calculating the coefficients of the displacements were combined with elastic equations to determine the formulas which were used in calculating for displacements (u, v and w) and non-dimensional stresses (σୖୖ, σ୕୕, τୖ୕, τୖୗ ܽ݊݀ τ୕ୗ) at various angle fiber orientation (0 ଴ , 15଴ , 30଴, 45଴ , 60଴ , 75଴ and 90଴ ) and various span to thickness ratio, α(5, 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100) and for all the twelve boundary conditions. These formulas were used to analyze some typical anisotropic rectangular thick plates by the help of a functional excel worksheet program. The numerical results obtained for displacement (w) and stresses (σതത୶୶തത and σതതത୷୷തത) at aspect ratio of 1.0 and span to thickness ratio of, 20.0, 10.0, and 7.14286, in this study, when compared with the results of Shimpi and Patel showed percentage difference of 0.59, 1.47, 2.70; 0.62, 1.20, 1.91 and 1.31, 0.97, 3.91% which is in good agreement. Hence the developed method is recommended for analyzing thick rectangular anisotropic plates.
Open Access
Comparative analysis of techniques for estimating geohydraulic properties and aquifier vulnerability in Imo River Basin, SouthEastern Nigeria
(Federal University of Technology, Owerri, 2019) Emberga, Terhemba Theophilus
Comparative Analysis of Techniques for Estimating Geohydraulic properties and Aquifer Vulnerability in Imo River Basin, Southeastern Nigeria was carried out to determine the most suitable and cost effective techniques for the determination of hydraulic properties and groundwater vulnerability in the Imo River Basin. The basin which lies between Latitudes 4° 38' and 6° 01' N and Longitudes 6° 53' and 7° 32' E with an area extent of about 9100 km is underlain by the Ajali, Nsukka, Imo Shale, Ameki, Ogwashi-Asaba and Benin Formations. Five hundred and sixty-nine (569) vertical electrical soundings (VES) using the ABEM Terrameter (SAS) 4000 with maximum electrode spacing of 1000 m were acquired in the study area. Thirty (30) parametric soundings out of the entire VES data points were carried out in the vicinity of existing boreholes for comparative analyses and quality control. Twenty (20) sandstone samples collected from the six (6) formations were sieved and the resulting data processed to obtain hydraulic conductivities of aquiferous units. Comparatively, Da-Zarrock parameters (transverse unit resistance and longitudinal conductance) were used to determine aquifer depth, thickness and hydraulic characteristics from VES Data. Additionally, estimates of hydraulic conductivity were made using the techniques of Niwas & Singhal and the Heigold’s method. A New model that is Novel and formation sensitive was also developed using resistivity and existing pumping test data. The mean aquifer resistivity revealed 1397.96 in Ajali, 2116.92 in Ameki, 2188.15 in Benin, 632.55 in Imo shale,1355.08 in Nsukka and 2072.91Ω m in Ogwasi-Asaba Formations while the mean aquifer thickness in Ajali revealed 40.83, while those in Ameki were 42.68, 39.38 in Benin, 26.78 in Imo Shale, 36.34 in Nsukka and 37.39 m in Ogwasi-Asaba. The study also revealed the aquifer thickness of 122.04 in Ajali, 121.86 in Ameki, 114.46 in Benin in 73.73 in Imo shale, 36.92 in Nsukka and 109.66m in Ogwasi- Asaba. The results of the hydraulic conductivity and that generated with the model revealed average values of 13.19, 1.74 and 4.62 m/day respectively. The hydraulic conductivity values estimated using the empirical formulae of Hazen, Kozeny-Carman, Breyer, Slitcher and USBR have mean values of 1.55, 256.8, 0.58, 2.82 and 0.046 m/day respectively. These results were validated with the existing pumping test data using Artificial Neural Networks. Mean Transmissivity (Tmean) and Storativity values computed from the hydraulic conductivity data revealed values of 140.8 m2 /day and 5.3 × 10-5 , respectively for the aquiferous units in the Ajali Formation. In the same vein, Tmean of 193.5 m2 /day and mean storativity of 5.54× 10-5 were estimated for Ameki Formation aquifers, while Benin Formation aquifers revealed Tmean of 784m2 /day and mean storativity of 5.11 x 10-5. The aquifers in the Imo Formation have a mean transmissivity Tmean = 205.2 m2/day with a mean storativity of 3.48× 10-5 . The aquifers in the Nsukka Formation have a mean transmissivity Tmean = 211.5 m2 /day with a mean storativity of 4.8 × 10-4 while the aquifers in the Ogwasi/Asaba Formation have a mean transmissivity Tmean = 100.2 m2 /day with a mean storativity of 4.86 × 10- 5 . The vulnerability of the aquifers evaluated using Geologic (DRASTIC and GOD) and Geophysical (Integrated Electrical Conductivity, IEC) models generated vulnerability maps which displayed areas within the northern part of the study area to have low and moderate vulnerabilities while the southern part has aquifers with high vulnerability to pollution. The estimated percolation time of contaminants using IEC model revealed that it will take contaminants from several months to about 25 years to get to the groundwater system in the study area. The good correlation of hydraulic conductivity results between the new model and existing pumping data implies that generated model can substitute the laborious and expensive pumping tests of boreholes in areas with similar geologic formations.
Open Access
In vitro antioxidant and antimalaria properties of the plants chasmanthera dependens (hochst)and dictyandra arborescens (welw.)
(Federal University of Technology, Owerri, 2021) Enenebeaku, Uchechi Emmanuela
Crude aqueous and methanolic extracts of leaves, stem and roots of Chasmanthera dependens and Dictyandra arborescens suggested from their ethno-medicinal uses to possess antimalarial activities were evaluated for phytochemical, in vitro antioxidant, toxicity, and antimalarial activities. Phytochemicalanalyses were carried out using standard qualitative and quantitative analytical methods. In vitro antioxidant potentials of the extracts were determined by their abilities to scavenge 2, 2-diphenyl-1- picrylhydrazyl radical, nitric oxide radical and hydrogen peroxide. The antioxidant potentials were further determined by the ferric reducing antioxidant power and total antioxidant capacity using standard methods. Acute toxicity was carried out using modified Lorke’s method, sub-acute toxicity of the extracts were also determined using adult male albino rats. Antimalarial activities of the extracts were determined using male Swiss albino mice infected with Plasmodium berghei. Methanolic extracts of D.arborescens roots which showed the highest antimalarial activity was subjected to separation by silica gel column chromatography while bioassay was carried out by testing the antimalarialactivities of the fractions on male Swiss albino mice. Hexane fraction of the extract showed the highest antimalarial activity and was sub fractionated to obtain two purer eluates coded EA and EB which were characterized using Gas Chromatography – Flame Ionization Detector (GC-FID), Fourier Transform Infrared (FTIR) spectroscopy, Gas Chromatography-Mass Spectrometry (GC-MS) and Molecular docking analyses. Phytochemical screening of the extracts revealed the presence of tannins, saponins, alkaloids, cardiac glycosides, terpenoids, steroids, phenols, flavonoids, oxalate and phytate in varying amounts. The phytochemicals were more in the methanolic extracts than in the aqueous extracts. Scavenging of DPPH, nitric oxide, H2O2 radicals, reducing power ability and total antioxidant activity were concentration-dependent. Activities of the extracts for DPPH, nitric oxide and H2O2 differed significantly (p˂0.05) from the standard antioxidant. For ferric reducing antioxidant power, methanolic extract of D.arborescens roots and methanolic extract of C. dependens roots showed the best reducing ability. Methanolic extract of D. arborescens root showed the highest (2352.94 ±164.87mg AA/g extract) total antioxidant capacity. Extracts of the leaves, stem and roots of D. arborescens did not show any mice toxicity or mortality even at 5000 mg/kg body weight but aqueous and methanolic extracts of C. dependens stem recorded death at 2900 mg/kg b.wt and 5000 mg/kg b.wt. Sub-acute oral toxicity test of the extracts revealed significant increase (p ˂0.05) on haematological parameters (PCV, Hb, RBCs, WBCs, MCH, Neutrophils, Lymphocytes and MCHC) at 200 mg/kg-1 body weight. For biochemical parameters (ALT, AST, ALP, total protein, and albumin), extracts did not significantly differ (p˂0.05) from the standard and normal control. All the extracts showed significant (p˂0.05) antimalarial activities compared to the untreated control. These activities however, differed (p˂0.05) from the standard antimalarial drug (artesunate). Methanolic extract of D.arborescens root showed the highest antimalarial activity by reducing percentage parasitemia from 75.2% on day 3 to 16.8% on day 14 after treatment. Column chromatographic separation of this extract gave five fractions at different solvent mixtures. Bioassay revealed that hexane soluble fraction recorded the highest antimalarial activity, and sub-fractionation of this fraction yielded two purer eluates -EA and EB. Phytochemical analysis with Gas chromatography- Flame ionization detector (GC-FID) revealed various phytochemicals with known antimalarial and antioxidant activities. FTIR spectroscopy revealed the presence of functional groups such as alkanes (-CH2-), α-halogeno carboxylic acids (C=O), primary alcohols (C- OH), halides (C-Cl), non conjugated alkenes (C=C), esters (OC – H), aliphatic esters (R-O-R), etc. These functional groups were confirmed by GC-MS analysis which xxi recorded various bioactive compounds such as 1,2 dichloro propane, 1-Octadecene, cis- alpha- bisabolene, Dichloroacetic acid tridecyl ester, 9,17 Octadecadienal, (Z)-, cis-13-Octadecenoic acid, Heptadecanoic acid, 16 methyl-, methyl ester, Bis (2-ethylhexyl) phthalate, Bis(3-methylbutan-2yl) phthalate, Carbonic acid prop-1-ene - 2yl-tetra, 5-Octadecene, (E)-, Hexadecanoic acid methyl ester, 10-Octadecenoic acid methy ester Butyl octadecyl ether methyl tetradecanoate, Heptasiloxane, 1,1,3,3,5,5,7,7,9,9,11,11,13,13 tetradecamethyl. In molecular docking analysis, these bioactive compounds showed various degrees of binding affinities and molecular interactions with two antimalarial protein targets - lactate dehydrogenase (1OC4) and Plasmepsin II (1SME). Binding affinity of Bis(2-ethylhexyl) phthalate and Bis(3-methylbutan-2-yl) phthalate were close to that of the standard antimalarial drug (artesunate) suggesting that these two compounds were responsible for the antimalarial activity exhibited by methanol extract of D.arborescens root. ADMET properties of these two compounds equally suggest no harmful or toxic effects when compared to the standard antimalarial drug (artesunate).
Open Access
Hybrid result processing and management system for Nigerian universities
(Federal University of Technology, Owerri, 2021) Etus, Chukwuemeka
Hybrid Result Processing and Management System (HRPMS) is an optimized model that automates result computation, vetting, approval, checking, and transcript processing workflow across standalone and client-server cross-platform. It is designed to address the challenges of using only a single-platform system (legacy or modern) in results processing and management, currently existing in Nigerian universities. The objective of the research, therefore, is to develop an offline, online, scalable, decentralized, inter-networked, normalized, and secured 3-tier system able to further improve computerized automation of result processing and management in Nigerian universities, in line with the universality of management and institution-specific policy standards. The survey analysis method was used to expose the deficiency of the single-platform system which necessitates developing the HRPMS. The Agile methodology adopted followed the Scrum method for rapid Test-Driven Development (TDD), and leveraged the jMeme Metaheuristic Optimization Framework (MOF) to hybridize and optimize the standalone (offline) and the client-server (online) platforms to build the HRPMS socket middleware cross-platform application. Again, the Agile 4-quadrant approach was followed to test and validate the HRPMS development. The tools and materials deployed for the design and programming of the HRPMS subsystem modules include the Unified Modelling Language (UML), the Excel VBA Binary, Java IDE and libraries, MS POI, and API plugins, PHP IDE, and SQL DBMS. While the web application, the MySQL database, and the FTP servers were deployed to test the system across a wireless extranet. The HRPMS performance was validated through hypotheses test and Multivariate Linear System (MLS) statistical analysis on MatLab, with a set of non-functional variables (x1-x6) and dual-sample data collected using the Delphi technique. The results showed that the existing single-platform model is about 53.8% deficient, but the HRPMS is an improvement of the existing system with a mean Performance Difference (PD) of 1.043458X10-8. Therefore, it presents a more efficient, more secured, hard-to crash, and optimum cross-platform system with a hybrid database emulator to map, parse and upload flat-file data into a relational database for transcript processing. Finally, this work recommends the convergence of technologies, services, and processes as information system integration and process automation swiftly erode boundaries that separate functional platform groupings.
Open Access
Numerical and experimental studies of the energy requirements for cutting selected tuber crop tissue and vegetables
(Federal University of Technology, Owerri, 2021-07) Asonye, Gladys Uche
Numerical and experimental studies of the cutting energy requirements for selected tuber crop tissue and vegetables was undertaken in this research work. Prediction models using dimensional analysis based on Buckingham pi theorem were developed for the cutting energy requirements for four selected crops which are indigenous to the area of study; tuber crop (cocoyam) (Colocasia esculenta), fruit vegetable (okra) (Abelmoschus esculentusL.), bulb vegetable (onion) (Allium cepa.) and fruit vegetable (garden egg) (Solanium marcrocarpon). The developed cutting energy prediction models using dimensional analysis based on Buckingham pi theorem for cocoyam (Colocasia esculenta), okra (Abelmoschus esculentus L.), onion (Allium cepa) and garden egg (Solanium marcrocarpon) were validated with experimentations. High coefficient of determination (R2 ) values of 0.98, 0.99, 0.98 and 0.98 respectively obtained for cutting energy values between the predicted and the measured values with the developed automated cutter showed that the mathematical models are good. The developed arduino-controlled automated cutter consists of two parts; the hardware and oftware components. The hardware is composed of an electronic windshield motor, four 25mm2 stainless steel pipes of 4cm height for supports, a 35cm x 29cm x 8mm stainless steel plate for the base, a 12cm stainless threaded shaft and 4 pieces of 5cm stainless angle irons. The software consists of Arduino microprocessors (Integrated Development Environment, IDE), load cells (sensors) and a Liquid Crystal Display (LCD). The arduino processor automatically and effectively measures, records and stores cutting variables (speed, force, displacement and time) with minimum human supervision. Connecting the cutter to an electrical power source switches on the electronic windshield motor, which causes a rotational motion of the shaft and a subsequent reciprocating motion of the knife holder. The cutting process which is a non-reversible system involves both compressive and shearing deformations. The operational process involves speed selection, movement of knife edge through product, exertion of reactive force on the load cell and computations. The reactive force exerted on the load cell is measured and automatically relayed to a computer via a Universal Serial Bus (USB) port for storage and further processing. Matrix Laboratory (MATLAB) which is a high performance language for technical computing intercepts the stored values and plots the resulting graph of force of cut against displacement which is used in calculating the energy of cut. Variables involved in the model development using dimensional analysis based on Buckingham pi theorem were; tool weight, distance of cut, tool edge thickness, cutting speed, varying crop sizes, crop moisture content, crop contact area and crop density. Lastly, optimization of the cutting process was carried out by studying the interactive effects of three variables on the energy requirement to cut the select crops. It involved experimentations using the Randomized Complete Block Design (RCBD) layout and observing the effect of the different combinations on cutting energy requirements. These variables are cutting speeds and knife edge angles at 5 levels of 20, 25, 30, 35 and 40mm/min and 200 , 270 , 340 , 410 and 480 respectively with equivalent crop sizes of 33.68, 41.02, 45.34, 50.31 and 64.89mm for cocoyam (Colocasia esculenta); 11.23, 13.28, 17.82, 20.52 and 24.47mm for okra (Abelmoschus esculentusL.); 42.84, 51.78, 61.36, 77.35 and 84.10mm for onion (Allium cepa.) and 25.69, 32.87, 40.31, 47.69 and 52.73mm for garden egg (Solanium marcrocarpon). The three variables were observed to have significant effects on the cutting energy requirements for the four crops studied. The optimization of the cutting process was observed to occur at equivalent diameter of 33.68mm, cutting speed of 35mm/min and knife edge angle of 200 for cocoyam;47.61mm, 35mm/min and 200 for onion bulbs; 23.80mm, 50mm/min and 200 for okra and 45.41mm, 35mm/min and 200 for garden egg fruit. All the optimized results were at the lowest knife edge angle of 200 and the 35mm/min cutting speed except okra which occurred at the cutting speed of 50mm/min. The optimization study helped in the determination of the best combination of the chosen factors that would lead to maximizing energy consumption during the cutting process of the understudied agricultural crops. The results of this study find usefulness in designing, analyzing and optimization of the cutting process for these select crops.
Open Access
Utilization of functionalized biochar derived from water hyacinth eichhornia crassipies as green nano-fertilizers
(Federal University of Technology, Owerri, 2025-10) Irewale, Adewale Tolulope
This study investigated the production, characterization, and application of nano-biofertilizer synthesized from biochar (BC) derived from the aerial tissues of Eichhornia crassipes (water hyacinth), an invasive aquatic plant known for rapid growth and nutrient uptake that has adversely affected the aquatic ecosystem. BC was produced from its leaves (D1) and stems (D2) via pyrolysis at 600°C with residence times of 15, 30, 45, and 60 minutes, yielding 31% and 34% respectively. Incomplete carbonization was observed at residence time of 15 minutes while optimum pyrolysis occurred at 30 - 60 minutes. SEM and FTIR analyses revealed porous structures with surface functional groups including –COOH, –OH, C=C, and –S=O in but biomasses, although predominantly in D1. The biochar was alkaline (average pH 10.7), exhibited liming capacities of 14.76–28.94% CaCO₃ equivalent, zeta potentials of –34 to –38 mV, and particle sizes ranging from 146 to 583 nm. Although, deficient in copper and zinc, high nutrient availability was recorded with nitrogen (34,550 ppm), phosphorus (56 ppm), potassium (609 ppm), and water holding capacities between 1.58 and 2.26 g/g. BET isotherm modeling showed surface areas of 236.44–249.41 m²/g and pore volumes of 0.061–0.087 cm³/g, indicating mesoporous to microporous structures suitable for nanonutrient adsorption. Molecular dynamics simulations revealed thermodynamically favorable adsorptions between BC and ZnO and/or CuO nanonutrients, with a higher affinity for CuO. Comparative pilot field trials with nano-biofertilizer (NF) applied at 10 g, 20 g, and 40 g per 10 kg soil and a conventional fertilizer (CF) at 15g per 10kg soil (per manufacturer recommendation) showed that 10 g NF significantly enhanced growth and physiological parameters over other treatments. CF application resulted in higher plant mortality, indicating possible phytotoxicity of CF under the pilot field conditions. Comparative data obtained for plant height, leaf nitrogen content, chlorophyll concentration, number and surface area of leaves support the potential of biochar-based nanofertilizers as a low-dose, sustainable alternative to chemical fertilizers. Further studies are recommended to validate the predictions from molecular dynamics simulations, as well as to assess the environmental safety and scalability of the nanofertilizer in larger field trials.