CURRENT ISSUE   Vol. 5 No. 1 – March 2021

Articles


Multilinear Regression Model to Estimate Mud Weight

Oloro J. O. and Akhihiero T. E.

https://doi.org/10.36263/nijest.2021.01.0229

ABSTRACT
Estimation of mud weight poses a serious challenge to mud industries. In this study, a model was developed to tackle the problem of estimation of mud weight using multilinear regression techniques. The model was developed using data obtained from production records. The data include mud weight, water and other chemicals (materials) for nine different samples. The data were analysed to establish linearity and the data was substituted into the multiple regression to form a matrix with nine unknown regression parameters which was substituted into the regression equation to form the model. T-test and F –test was used to validate the model. Results from the test suggest that the developed model was reliable. The model was used to estimate mud weight for four samples and the results are reliable. The effect of each variable was also considered and results also show that each of the variables affects the mud weight.

Keywords: Regression, Fluid, Mud weight, Caustic soda, Barite

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Assessment of Uncharred Palm Kernel Shell as a Filter Medium in Low Rate Filtration

Jeje J. O. and Oladepo K. T.

https://doi.org/10.36263/nijest.2021.01.0246

ABSTRACT
This study examined the use of uncharred palm kernel shells as a filter medium in low rate filtration as a water treatment alternative. The filter column was made of 150 mm diameter PVC pipe about 1.8 m high. The filter medium (uncharred palm kernel shells) with size range 0.15 – 0.60 mm overlying two layers of graded gravels. The raw water passed through the filter medium and the effluent collected in a metal tank. The effluent was evaluated by monitoring the flow rate, turbidity, filtration rate, bacteriological quality and headloss across the filter bed for a daily six hour run for 14 days. The filter bed was cleaned using the throwing-over method after the filtration rate became appreciably very low at 1.20 l/min-m2. It was found from the results obtained that uncharred palm kernel shells could serve as an effective filter for low rate filtration relative to sand. An average hydraulic loading and filtration rate of 120.35 l/min-m2 and 5.5 l/min-m2 were achieved respectively. The turbidity of the filtered water reduced below 5.5 NTU after the eleventh day and the bacteriological treatment level though excessively high at 65 coliform/100 ml showed reducing tendencies (120/100 ml to 65/100 ml).

Keywords: Filtration, Uncharred palm kernel shells, Headloss, Low rate filtration, Potable water

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Electrical Conductivity of PA6/Graphite and Graphite Nanoplatelets Composites using Two Processing Streams

Umar M., Ofem M. I., Anwar A. S. and Usman M. U.

https://doi.org/10.36263/nijest.2021.01.0251

ABSTRACT
The percolation threshold (PT) of any polymer/particulate carbon composite depends on the processing, the dispersed state of the filler, the matrix used and the morphology attained. Sonication technique was used to make PA6/G and PA6/GNP composites employing in situ polymerisation, after which their electrical conductivity behaviours were investigated. While overhead stirring and horn sonication were used to distribute and disperse the carbon fillers, the composites were made in 2 streams 40/10 and 20/20. The 40/10 stream implies that while dispersing the carbon fillers in PA6 monomer, 40% amplitude of sonication was applied for 10 minutes whereas the 20/20 stream implies 20% amplitude of sonication for 20 minutes. In both streams, the dispersing strain imparted on the monomer/carbon mixture was 400 in magnitude. Purely ohmic electrical conductivity behaviour was attained at 9.75 G wt. % for IG 40/10 system. For composites in the IG 20/20 system, same was attained at 10.00 G wt. %. Electrical conductivity sufficient for electrostatic discharge applications was achieved above 15 G wt. % in the IG 40/10 system. Using the power law percolation theory, percolation threshold was attained at 9.7 G wt. % loading in IG 40/10 system, while same was attained at 7.6 G wt. % loading in IG 20/20 system. For the GNP based systems, percolation threshold occurred at 5.2 GNP wt. % in the INP 40/10 system whereas same occurred at 7.4 GNP wt. % in the IG 20/20 system.

Keywords: Electrical-conductivity, Graphite, Percolation-threshold, Amplitude, Sonication

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Vulnerability Assessment of Components in a Typical Rural Nigerian Power Distribution System

Omoroghomwan A. E., Igbinovia S. O. and Odiase F. O.

https://doi.org/10.36263/nijest.2021.01.0237

ABSTRACT
The major aim of any power system is the continuous provision of safe, quality and reliable electric power to the customers. One of the greatest challenges to meeting up with this goal is the failure of components in the system. In this article, the frequency of outages caused by failure of different components in the distribution system was investigated to ascertain the ones that are more susceptible to failure by comparing their proportions in the entire failure events. The outage data obtained from Irrua Transmission Station comprising Ehor, Ubiaja and Uzebba 33kV feeders were analyzed using Microsoft Excel while the hazard rates were measured using the failure rate index. Findings revealed that 93.77% of all the forced outages in the distribution subsystem in the power sector are caused by the high exposure rate of the bare aluminum conductors used in the construction of the various overhead feeders. Subsequently, the yearly failure rates of aluminum conductors, cross arms, relay, insulators, fuses, electric poles, breakers, transformers, isolators, cables lightning surge arresters were found to be 836.0, 17.5, 17.0, 10.3, 4.3, 2.0, 1.5, 1.3, 1.0, 0.5 and 0.3 respectively in the studied network. A comparison between this study and a related work showed that the rural feeders are more prone to faults as compared to the ones in the urban areas. It was therefore recommended that regular tree trimming along the network corridor should be done. Proper conductor size should be used in every subsequent construction and every segment with undersized conductor should be replaced with the appropriate size. This study will help the power system engineers in the design, construction, maintenance and operation of the distribution power system for optimum and improved system performance.

Keywords: Vulnerability assessment, Power system components, Nigeria power sector, NEMSA, Bathtub curve, Failure rate, NERC

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Physicochemical Characteristics of Selected Sachet and Bottled Water in Abraka, Delta State

Otobrise C., Azuh T. C., Mmakwe E. I., Ogbakpa E. and Tolorun C. O.

https://doi.org/10.36263/nijest.2021.01.0248

ABSTRACT
Some physicochemical properties of five brands of sachet and five brands of bottled water sold/produced in Abraka; Ethiope East Local Government Area of Delta State was investigated. Amounts of heavy in the water samples were also determined. The results were compared with World Health Organization (WHO) standards and Nigerian Standard for Drinking Water Quality (NSDWQ) respectively. Seventy percent of the samples had pH levels below the minimum level of 6.50 recommended by WHO and NSDWQ, suggesting that the water samples are acidic. The slight acidity of the water samples may not be unconnected to impurities from poor treatment techniques. Results for other physicochemical parameters: EC (78.60 ± 34.06 µs/cm), TDS (42.80 ± 18.46 mg/L), Temperature (30.02 ± 0.46 OC), Cl- (16.88 ± 7.01 mg/L), NO3– (0.12 ± 0.05 mg/L), NO2– (<0.001 mg/L), TH(10.60 ± 7.09 mg/L), Cu(0.05 ± 0.00 mg/L), Fe(0.34 ± 0.19 mg/L), Zn(0.11 ± 0.02 mg/L) and Mn (0.03 ± 0.00 mg/L) for sachet water samples; EC (99.60 ± 76.18 µs/cm), TDS (54.20 ± 41.84 mg/L), Temperature (29.96 ± 0.21 OC), Cl- (20.85 ± 17.44 mg/L), NO3– (0.12 ± 0.03 mg/L), NO2– (0.01 ± 0.01 mg/L), TH(15.00 ± 16.36 mg/L), Cu(0.04 ± 0.01 mg/L), Fe(0.20 ± 0.15 mg/L), Zn(0.11 ± 0.03 mg/L) and Mn (0.09 ± 0.01 mg/L) for bottled water samples; were within permissible limits, indicating that the water samples are good enough for human consumption.

Keywords: Sachet water, Bottled water, Physicochemical characteristics, Potable, Abraka

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Design Mix Formulation and Optimization of Metakaolin Based Alkali Activated Geopolymer Concrete with the Taguchi Method

Okovido J. O. and Yahya I. A.

https://doi.org/10.36263/nijest.2021.01.0249

ABSTRACT
Concrete mix formulation is the science of deciding relative proportions of ingredients of concrete, to achieve desired properties in the most economical way. Formulation of concrete mix requires adequate knowledge of the properties of its constituents. Aluminosilicate materials have recently found applications in construction industry due to their unique and flexible properties. The metakaolin used for this study was the locally sourced kaolin calcined at 750oC. The alkali activating reagents include a fixed concentration of sodium silicate solution and sodium hydroxide solutions of three different concentrations. Strength development of metakaolin – based geopolymer concrete is quite different from that of ordinary Portland cement concrete due to differences in their constituents, hence, the need for special formulation, most especially when high strength is required. Taguchi method was adopted in this study to formulate mix proportion for high compressive strength of geopolymer concrete at ambient curing condition. Four parameters were selected that are more likely to influence the compressive strength of metakaolin – based geopolymer concrete, these include aggregate content, alkali – binder ratio, alkali reagent ratio and alkali reagent concentration. The effect of these parameters on the density, workability and compressive strength at 3, 7 and 28 days are determined. The result showed that an optimum mix obtained from a formulation formula (2.75SiO2 * Al2O3 * 0.55Na2O * 6.8H2O) produced a compressive strength of 62MPa at 28 days of open air curing. It was revealed that the molar concentration of the alkali reagent (sodium hydroxide) should be kept within 10M range for an open air curing, the alkali reagents to binder ratio should be kept at 0.7 or less with no addition of water to achieve reasonable workability. Also, it has been observed that the bulk density of metakaolin – based geopolymer concrete that yielded substantial strength fall within 2250kg/m3 and 2350 kg/m3.

Keywords: Aluminosilicate Material, Geopolymer Concrete, Taguchi Method, Mix Formulation, Mix Optimization

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Protection of Ecosystem and Preservation of Biodiversity: The Geospatial Technology Approach

Ogunlade S. O.

https://doi.org/10.36263/nijest.2021.01.0253

ABSTRACT
The protection of ecosystem and preservation of biodiversity through the approach of geospatial technology was the aim of this research. The channel was monitoring the spatial transformation of the Federal University of Technology, Akure, Nigeria between year 2002 and year 2018 using Satellite Remote Sensing and Geographical Information System techniques. Landsat 7 Enhanced Thematic Mapper (ETM) plus of year 2002, Landsat 8 Operational Land Imager (OLI) and Thermal Infrared Sensor (TIRS) of year 2014 and year 2018 all of 32m resolution were the satellite images obtained for the study. These images were processed with supervised maximum likelihood classification algorithm using ArcGIS 10.3 software. To validate the classification and ensure high accuracy, an accuracy assessment was performed using training samples from 60 points on each of the satellite imagery on a reference image from google earth combined with ground data collected on actual visitation to the study area to verify the true land-cover type existing on the site. The resultant images deemed fit for analyses were classified into built-up, thick vegetation, light vegetation and bare land, land cover classes. Microsoft Excel spreadsheet was used to perform land cover area calculations through which the land cover dynamics and the spatial expansion were identified. The result showed built-up (13.58%, 14.59%, 20.75%); thick vegetation (33.78%, 26.26%, 12.18%); Light vegetation (24.57%, 32.29%, 30.51%); Bare land (28.08%, 26.26%, 36.56%) for the three years respectively. A special focus was put on the general depletion of the (thick and light) vegetation of which trees are a major actor. These depletion were adduced to the positive transformation of other land cover classes through the underlining landuse. The study concluded that alteration, depletion and consequent disappearance of trees in the green ecosystem is a threat to environment’s sustainability and the protection of ecosystem and preservation of biodiversity. The study recommended the research as a tool to controlling the removal of trees and thick forest, growing more trees and plants among other factors to protect ecosystem and preserve biodiversity.

Keywords: Ecosystem, Geospatial Technology, Land cover, Land use, Satellite Images

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Evaluating the Quality of Spatial Data for the Analysis of Climate Variability in the Coastal Region of Nigeria

Agbonaye A. I. and Izinyon O. C.

https://doi.org/10.36263/nijest.2021.01.0236

ABSTRACT
The lack of truly reliable data for climate change analyses and prediction presents challenges in climate modeling. Needed data are required to be hydrologically/statistically reliable to be useful for hydrological, meteorological, climate change, and estimation studies. Thus, data quality and homogeneity screening are preliminary analyses. In this study, the homogeneity of the climatic data used for analyses of climate variability was conducted in the coastal region of Nigeria. Climatic Research Unit (CRU 0.5× 0.5) gridded monthly climatic data for sixty years (1956- 2016) for nine states of the coastal region of Nigeria obtained from internet sources were validated with the Nigerian Meteorological Agency (NiMet) data to assure adequacy for use. The data were tested for normality using the Shapiro-Wilk (S-W) test, D’Agostino-Pearson omnibus test, and skewness test. Four homogeneity test methods were applied to 257 locations in the nine states of the coastal region of Nigeria and they include Pettit’s, Standard Normal Homogeneity Test (SNHT), Buishand’s and Von Neumann Ratio (VNR) tests. The results of the validity analysis indicated that the CRU data are very reliable and thus justified their use for the further analysis carried out in the study. Also, the results obtained indicated that CRU climatic data series were normally distributed and parametric methods could be used in further analysis of the data. Rainfall data homogeneity was detected for Bayelsa, Delta, Edo, Lagos, Ogun, and Ondo states and inhomogeneity for Akwa Ibom, Cross Rivers, and Rivers States. Also, temperature data inhomogeneity was detected for all the states in the study area.

Keywords: Climatic data, Normality, Homogeneity, Climate change, CRU

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Storage Moduli of in situ Polymerised and Melt Extruded PA6 Graphite (G) Composites

Umar M., Ofem M. I., Anwar A. S. and Makama A. B.

https://doi.org/10.36263/nijest.2021.01.0252

ABSTRACT
Four PA6/graphite (G) composites systems were made. Two in situ polymerisation equivalent in mixing strain and two melt extrusion of equivalent processing strain. The effective modulus of the carbons, room temperature storage modulus and storage modulus at 80 ⁰C were evaluated using Dynamic Mechanical and thermal Analysis (DMTA). Melt processing, was employed to make PA6/carbon composite systems over a range of loadings of Graphite (G) and Graphite Nano Platelets (GNP) fillers. Melt extrusion was carried out using 100/6 processing condition, which indicates an extrusion screw rotation frequency of 100 rpm applied for 6 minutes (min) and 200/3 processing conditions, of 200 rpm for 3 min. For in situ polymerised systems G and GNP dispersion was made using two similar conditions designated as 40/10 and 20/20. Here, 40/10 indicates that sonication amplitude of 40% was applied for 10 min, whereas in the 20/20 conditions, amplitude of 20% was applied for 20 min. For in situ Nano P INP 40/10 systems weak interaction between PA6 and GNP is indicated by the very low modulus enhancement above glass transition temperature (Tg). The modulus behaviour shows that the reinforcement provided by GNP is not significant relative to unfilled PA6, despite the low loading levels. A similar, but less pronounced, behaviour is observed for INP 20/20 system. Effective modulus for the in situ polymerised systems INP 40/10, was 4.8 GPa. Due to the low loading level of GNP used and the better reaction rates, an extrapolated modulus of 22.4 GPa is obtained in the INP 20/20 system. For G200/3 and G100/6 the trend of increasing modulus with GNP loading is not followed exactly. On all levels of loading, the relative modulus values of the INP 20/20 system are higher than those of the 40/10 system, a reflection of retention or improvement in the aspect ratio of the GNP due to less intensive sonication.

Keywords: In situ-polymerisation, Melt-extrusion, Effective-modulus, Storage-modulus

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An Assessment of Degradation of Soil Properties in Kabba College of Agriculture, Kogi State, Nigeria

Babalola, T. S., Ogunleye, K. S., Lawal, J. A. and Ilori, A. O. A.

https://doi.org/10.36263/nijest.2021.01.0240

ABSTRACT
Some soils in Kabba College of Agriculture, Kogi State, southern guinea savannah zone of Nigeria, were assessed to ascertain the levels of degradation of soil properties. The rigid grid soil survey method was used to identify seven soil units. Soils were sampled at 0-20 cm and 20-40 cm soil depth and analyzed for physical and chemical properties using standard methods. Levels of degradation were obtained by comparing laboratory data with the standard land/soil requirement (indicators/criteria) for grouping lands into different degradation classes of 1 to 4 (non to slightly, moderately, highly, and very highly degraded). Results showed that units D (soghum) and E (citrus) were very highly degraded (Class 4) of exchangeable potassium; units C (yam), D and E were highly degraded (Class 3) of organic matter. Other units were moderately degraded (Class 2) of base saturation, bulk density and total nitrogen. There was no degradation of available phosphorus and exchangeable sodium percentage in all the units. Physical and chemical degradation took place in the study area with respect to bulk density, base saturation, total nitrogen, potassium, and organic matter. Sustainable management practices that will promote good bulk density and organic matter accumulation should be encouraged.

Keywords: Degradation, Assessments, Chemical, Physical, Indicators

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Impact of Seasonal Variations on the Colonial Populations of Bacteria and Fungi in Soil and on Buried Plant Stems

Nwokoro O. and Ekwem O. H.

https://doi.org/10.36263/nijest.2021.01.0242

ABSTRACT
Forest soils and stems buried in them usually have varying degrees of colonization and abundance of bacteria and fungi. This study was undertaken to determine the effects of seasonal variations on the population of bacteria and fungi isolated from forest soil and on plant stems buried in the soil. Soil sampling and stem burial studies were conducted over a 12-month period in 2019. Serially diluted soil samples were plated on suitable media for bacterial and fungal growth and thereafter counted after incubation. Buried stems were removed from the soil, rinsed and placed in flasks containing suitable media for fungal and bacterial cultivation. Colonial growth was counted after incubation. Soil moisture was highest during the wet season months of July (27.7%), August (23.5 %), September 26.1 %) and October (29 %) whereas the average soil moisture content was lowest in the dry season. Seasonal pH did not significantly affect microbial population levels in the various months. Colony counts for Pseudomonas spp. during the dry season months (January, February, March and April) were very low. Growth of the bacterium showed peaks in the May through October during which counts reached 109 cells per gram of soil except in August with counts of 108 cells per gram of soil. Micrococcus spp. and Bacillus spp. also showed similar trends in colony counts with little variations. Fungi were generally fewer in number than bacteria and only one peak which reached 107 cells/g soil was obtained for Fusarium spp. and Rhizopus spp. in September and October respectively. The density of Trichoderma spp. per gram of soil peaked at 106 cells in June, July, September and October. Counts for Aspergillus spp. was negligible in January, February, March and April but reached 106 cells per gram of soil in June, July and August. The colonization of Pseudomonas spp. on buried plant stem varied between 62% in June to 76% in October while Micrococcus spp. had levels which varied from 65% in May to 84% in June and 72% in October. Fusarium species were found most frequently on the stem every month except in February, March and April. Low colonization of Aspergillus spp. on stems occurred in January, February, March, November and December. Highest numbers of this organism was found in August, September and October. Rhizopus spp. was observed in 85 and 80% of the stem in September and October respectively but lower percentages of colonization occurred in January, February, March and April. In all the dry season months (January-April), all bacterial and fungal populations had low densities but their counts increased in the rainy season. Fungi were generally fewer in number than bacteria in both soil and stem burial experiments.

Keywords: Microbial population, Soil sampling, Stem burial, Forest soil, Colonization rate

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Assessing the Impact of Urbanization on Outdoor Thermal Comfort in Selected Local Government Areas in Ogun State, Nigeria

Akinbobola A. and Fafure T.

https://doi.org/10.36263/nijest.2021.01.0243

ABSTRACT
This study seeks to assess the land use land cover (LULC) and spatial-temporal trends of six outdoor thermal comfort indices in four Local Government Areas (LGAs) of Ogun state, Southwestern, Nigeria. Data used for this study are air temperature, relative humidity, cloud cover and wind speed which span from 1982 to 2018. These data were obtained from ERA-INTERIM archive. The 1986, 2000 and 2018 used for the analysis of the LULC were from the satellite imagery hosted by the United States Geological Survey (USGS). Landsat Thematic Mapper, Landsat 7 and Landsat 8 Operational Land Imager data of 1986, 2000 and 2018 to assess the changes that have taken place between these periods. Thermal comfort indices such as Effective Temperature (ET), Temperature Humidity Index (THI), Mean radiant temperature (MRT) and Relative Strain Index (RSI) were used. Rayman model was used for the computation of the three thermal comfort indices (MRT, PET, PMV). The results show decrease in vegetation, forest, and an increase in percentage of built-up areas between 1986–2000, and 2000–2018. A rapid increase in built-up areas in the three (Abeokuta South, Ifo, Shagamu,) of the four LGAs, while one (Ijebu East) has a slow increase in the built-up areas. The trend in the thermal comfort indices also shows that thermal discomfort had been on increase for the past 37 years and it was observed that the level of comfort has deteriorated more in the last decade compared to the previous decade especially in the built-up areas. This work suggests a framework for evaluating the relationship between the quantitative and qualitative parameters linking the microclimatic environment with subjective thermal assessment. This will contribute to the development of thermal comfort standards for outdoor urban settings. Also, the study will help urban planners in their decision making, and in heat forecast.

Keywords: Thermal comfort, Urbanization, Temperature, Urban space, Trends

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Models for Estimating the Hearing Threshold of Quarry Workers at High Frequencies

Akanbi, O. G., Oriolowo, K. T., Oladejo, K. A., Abu, R., Mogbojuri, A. O. and Ogunlana, R.

https://doi.org/10.36263/nijest.2021.01.0254

ABSTRACT
It is widely known that quarry industry has great importance in developing countries, such as Nigeria. There is paucity of information regarding effects of noise experienced by quarry workers during their working time. Therefore, this study investigated the influence of age of workers, years of exposure of workers and noise level of the machine used in quarry on hearing threshold. A factorial design of experiment was employed for the investigation. Two hundred and four quarry workers volunteered for this study from four quarries in South western Nigeria. Emitted noise, which quarry workers were exposed to during machinery operation, was measured with a digital sound level meter and workers hearing threshold was measured in an audiogram sound proofing testing booth at standard conditions. Predicted models were established from experimental design to determine main and interactions effects towards the response (hearing threshold). These were statistically analysed using analysis of variance (ANOVA). All terms of the models were significant at p<0.05. The best fitted model was at 4kHz (R2 = 0.639, p<0.05). The magnitudes of the main effect of the factors are in ascending order of noise level >years of exposure>age. The analysis of the experimental response indicated that there is no interaction of any factors on the hearing threshold. It can be concluded that age, years of exposure and noise level have main effects at various capacities at different frequency to predict the hearing threshold of the quarry workers. This work determined the factors and the predicted model to spell out safe hearing threshold of quarry workers that fitted for the job at a particular noisy workstation as well as ensuring comfortable, safe and effective workstation design.

Keywords: Factorial design, Safe hearing threshold, Quarry workers, Noise level, High frequency

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Modelling of Input Parameters for Power Generation using Regression Models

Agbondinmwin U. and Ebhojiaye R. S.

https://doi.org/10.36263/nijest.2021.01.0241

ABSTRACT
In this study, multiple linear regression models were employed in the correlation of gas supply and power generation using a gas Power Plant in Niger Delta, Nigeria as a Case study. From the analysis based on outlier detection, reliability analysis and test of homogeneity, it was observed that the independent variable data such as ambient temperature, gas pressure and compressed temperature failed normality test. Therefore, the use of any linear model for either analysis or modelling of the data was not acceptable. Data used for reliability analysis of the gas pressure and compressed temperature difference were positively correlated with power generation, having a covariance value of 0.639 and 113.148. The ambient temperature was negatively correlated with power generation, having a covariance value of 14.564. The positive value showed that both dimensions exclusively increased and decreased together with respect to the output while the negative value showed that increment in value of one variable led to decrease in the value of the other, and vice versa.

Keywords: Natural gas, Power generation, Regression models, Power plant, Ambient temperature

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Exposure to Atrazine Impairs Behaviour and Growth Performance in African Catfish, Clarias gariepinus (Burchell, 1822) Juveniles

Opute P. A. and Oboh I. P.

https://doi.org/10.36263/nijest.2021.01.0263

ABSTRACT
Clarias gariepinus juveniles of average weight, 17.57±1.95 g and an average length of 14.26±0.39 cm were exposed to environmentally relevant concentrations of 0 (control), 2.5, 25, 250, and 500 µg L-1 atrazine in a quality-controlled 28-day bioassay. Growth performance was assessed bi-weekly and fish samples were taken from different tanks to determine the relative growth rate, specific growth rate, feed conversion ratio, condition factor and behaviour. At the end of two weeks of exposure, the relative growth rate and the specific growth rate among exposed fish groups was found to reduce significantly (p<0.05) compared to the control, an indication of poor growth performance. The average specific growth rates (SGR) of control fish is 3.86±0.02 %/w at the end of the exposure duration while recording -0.64±0.09 in the 500 µg L-1 group. Feed conversion ratio increased significantly from control to the group with highest atrazine concentration. Condition factor (K) of fish among treatment groups showed significant decrease in values with increasing concentration of atrazine in a dose-dependent pattern. Atrazine exposure resulted in behavioural anomalies including erratic swimming, clinging to the water surface, loss of equilibrium, lethargy, and discolouration. The behavioural responses were found to be concentration-dependent. The length-weight relationships for both control and atrazine exposed fish exhibited positive allometric growth and significant relationships as depicted by the value of R2 (coefficient of determination) except in the fish group exposed to 500 µg L-1 atrazine which exhibited negative allometric growth. Findings from this study indicate interference with normal behaviour and growth performance of C. gariepinus juveniles with ecological implications in water bodies exposed to atrazine even at reduced concentrations.

Keywords: Clarias gariepinus, Atrazine, Behaviour, Growth, Condition factor

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Validating Gauge-based Spatial Surface Atmospheric Temperature Datasets for Upper Benue River Basin, Nigeria

Salaudeen A., Ismail A., Adeogun B. K. and Ajibike M. A.

https://doi.org/10.36263/nijest.2021.01.0259

ABSTRACT
Like most other countries of Africa, one of the main problems threatening effective impact modelling in Nigeria including Upper Benue river basin, dwells in lack of high-quality in-situ observation datasets at appropriate spatiotemporal scales. Gridded meteorological variables can serve as promising alternatives to in-situ measurements in data sparse regions, but then, require validations to assess quantitatively their level of accuracies and reliabilities. As a consequence, this study makes comparative analysis of two gauge-based, spatially interpolated surface atmospheric temperature datasets with in-situ measurements in seven distinct meteorological stations covering the period of 1982-2006. Correspondingly, spatial analysis and statistical measures were used to assess the performances of the gridded datasets from the Climate Research Unit (CRU) and the Climate Prediction Centre (CPC). Results from spatial distributions depict 8, 11 and 10 °C as observed minimum temperatures and 33, 36, 42 °C as observed maximum temperatures over the Cameroon highland (Gembu), the Jos plateau and at the northern fringes of the basin respectively. Consequently, both the CRU and CPC datasets captured remarkably well the observed temperature gradients along the varying topography, though with differing margins. The interannual variabilities indicate CRU dataset to better capture the signs and magnitudes of the observed anomalies as compared to the CPC data. Moreover, the CRU data was noted to be more outstanding in representing the observed features in seasonal temperature variations over most stations. Also, the shapes of the probability density function (PDF) for both datasets in minimum and maximum temperatures measured closely the shapes of the observed PDF. Trend analysis suggests CRU datasets to better represent the warming and the cooling trends than the CPC. Overall, the CRU datasets are the most outstanding in this study and is therefore preferred for water resource application over the study area.

Keywords: Assessment, Upper Benue river basin, temperature, CRU, CPC

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Seismic Waves Response Characteristics of Niger Delta Soils

Okovido J. O. and Kennedy C.

https://doi.org/10.36263/nijest.2021.01.0255

ABSTRACT
The study investigated the dynamic soil properties of States in Niger Delta region of Nigeria as a function of seismic activities. The down-hole seismic test was used to determine the response of the soils. The results of soil samples collected up to 30m depth, showed that the average young modulus increases with increase in depth, which ranged from 115.77±1.74 to 3231.17±1.01 kPa across the States. Also, shear wave velocity generally increases with increase in depth. The average shear wave velocity across the States ranged from 126.00±1.86 to 288.00±2.63m/s. Also, the average P-wave velocity increases with depth, with values across the States ranging from 310.60±3.51 to 656.00±3.69m/s. On the other hand, the void ratio was observed to be constant at certain range of depth, and in most with values across the States ranging from 0.651±.093 to 0.860±.067. Unlike void ratio, Poisson’s ratio fluctuates with depth, with values across the States ranging from 0.23±2.27 to 0.36±1.18. Based on the results, the Niger Delta region may be resistant to earthquake, but as an oil hub of Nigeria, it is also susceptible to earthquake that could be triggered by stress due to heavy load and seismic activities.

Keywords: Seismic activities, Soil dynamic response, Niger Delta region

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Analysis of Soil Quality Status and Accumulation of Potentially Toxic Element in Food Crops Growing at Fecal Sludge Dumpsite in Ubakala, Nigeria

Ogbonna P. C., Okezie I. P., Onyeizu U. R., Biose E., Nwankwo O. U. and Osuagwu E. M.

https://doi.org/10.36263/nijest.2021.01.0273

ABSTRACT
This study investigated the magnitude of potentially toxic element (PTE) in fecal sludge and the level of contamination of soil and food crops at Ubakala, Abia State, Nigeria. Soil samples were collected in four cardinal points at north (N), south (S), east (E) and west (W) of 1 m, 5 m, 15 m and 30 m from the edge of the fecal sludge dumpsite and standards (2 ppm, 4 ppm and 6 ppm) were prepared from 1000 ppm stock solution of the metals and used to plot the calibration curve with Atomic Absorption Spectrometer. Commonly consumed Carica papaya, Telfairia occidentalis and Manihot esculenta leaf samples were collected and analyzed to measure the concentrations of PTEs such as Cd, Zn Cr, Mn, Pb and Cu. The concentrations of Zn (12.41±0.30 mg/kg), Cd (0.07±0.00 mg/kg), Cr (4.47±0.34 mg/kg), Cu (2.12±0.03 mg/kg), Mn (8.13±0.03 mg/kg) and Pb (0.01±0.00 mg/kg) in dried fecal sludge are below the permitted limits of European Union. Concentrations of PTEs in soil and plants were Zn (13.40±1.20 to 100.80±1.40 and 1.24±0.06 to 56.02±5.02 mg/kg), Cd (0.07±0.01 to 0.92±0.02 and 0.0000±0.000 to 0.085±0.01 mg/kg), Cu (6.27±0.31 to 31.39±1.04 and 0.002±0.001 to 10.80±2.01 mg/kg), Mn (36.00±1.56 to 188.57±2.25 and 0.11±0.00 to 17.21±2.01 mg/kg), Cr (2.40±0.40 to 21.03±1.43 and 0.000±0.00 to 9.60±1.13 mg/kg) and Pb (0.09±0.02 to 0.35±0.03 and <0.00001±0.00 to 0.008±0.00 mg/kg), respectively. Zinc in soil is higher than FAO/WHO permissible limit while Cd in soil is higher than FAO/WHO limit and Dutch criteria for soil. Zinc and Cr in food crops are higher than FAO/WHO permissible limit. Strong positive relationship exist between Zn in soil and food crops (r = 0.616, p<0.05). Based on the findings, it is recommended that the fecal sludge should be treated with lime to precipitate PTE content of sludge and lowering the corresponding environmental risks.

Keywords: Fecal sludge, Soil quality, Food crops, Toxic elements, Ubakala

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Evaluating the Main Challenges to a Sustainable Physical Environment in Benin City

Onwuanyi, N. and Ojo, E. P.

https://doi.org/10.36263/nijest.2021.01.0268

ABSTRACT
In the shaping of cities as physical environments, planning governance is a principal factor which has sustainability implications for the entire urban system. This suggests that planning governance is a factor which has the potential to contribute to the occurrence of environmental challenges as well their resolution. Nigeria’s cities are facing many environmental challenges which constitute threats to sustainable development. This paper examines the main challenges to the development of a sustainable physical environment in Benin City, Nigeria’s ninth largest urban centre by population. Relying on archival records and observation, the study evaluates the city’s major physical environmental problems and their connection with planning governance; and thereafter, undertakes a comparison of planning governance features in the city with practice in the now sustainable, but once unsustainable environment of London City. The findings are that planning governance exerts a critical influence on the sustainable urban physical environment as in London City; that Benin City’s weak planning governance (as manifested by the absence of a master plan, inadequate personnel and equipment, a low public awareness of planning laws, a low level of compliance and a general lack of enforcement) is contributory to the emergence and subsistence of its environmental challenges. The conclusion is that the subsisting environmental challenges of Benin City are rooted in planning governance which, as presently run, lacks the capacity to achieve a sustainable physical environment. It is recommended that the city be re-directed to a trajectory of sustainable physical development through sweeping changes in planning governance and public enlightenment.

Keywords: Benin City, Environmental challenges, Physical planning, Sustainable development

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Bacteriological Assessment of Palms of Students of Delta State University, Abraka

Jemikalajah D. J., Enwa F. O. and Etaoghene A. D.

https://doi.org/10.36263/nijest.2021.01.0276

ABSTRACT
The bacteriological assessment of palms of students of Delta state University Abraka, was undertaken. A total of hundred samples were collected using a sterile swab sticks. Streak plate method was used and also biochemical test carried out following standard procedures. Results showed growth on ninety-three (93) cultured plates (93%). Bacteria isolates identified were Staphylococcus aureus, Escherichia coli, Proteus sp., Streptococcus sp, Bacillus sp., Salmonella sp. and Klebsiella. Staphylococcus aureus had the highest prevalence of 41% while, Salmonella sp (1%) was the least prevalent. Results also showed that female students had a higher incidence of bacterial load (58%) compared to the male students (42%), There is therefore a need to create awareness among students on good hand hygiene practices since the hand is a major reservoir of pathogenic organisms.

Keywords: Bacteria, Palms, hygiene, Staphylococcus aureus, Escherichia coli, Abraka

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Weighted Linear Combination Procedures with GIS and Remote Sensing in Flood Vulnerability Analysis of Abeokuta Metropolis in Nigeria

Oyedepo J. A., Adegboyega J., Oluyege D. E. and Babajide, E. I.

https://doi.org/10.36263/nijest.2021.01.0260

ABSTRACT
The study offered the opportunity for an evaluation of the role of Remote Sensing and Geospatial techniques in flood disaster risk management and development of spatial decision support system for flood risk assessment and management in Abeokuta metropolis. Datasets used includes cloud free high resolution satellite images and Shuttle Radar Topographic Mission (SRTM) data downloaded from earth explorer site. Soil data used was obtained from Food and Agriculture Organization (FAO’s) Harmonised World Soil Database, while rainfall data was obtained from the Climate Hazards Group InfraRed Precipitation Station. Maps of flood enhancing factors namely: soil types, rainfall intensity, drainage density and topography were created in Geographic Information Systems using same scale of 1: 50,000 and Geographic coordinate system (WGS 1984). All maps were produced in raster format with the same cell grid cell size of 0.0028 mm. They were then subjected to weighting by ranking and Multi-Criteria Analysis (MCA) using the Weighted Linear Combination. The study identified topography and land use as key factors contributing to flooding within Abeokuta metropolis. Obstruction of natural drainage channels by buildings aggravates disasters from flash flood events.

Keywords: Flash flooding, Flood Vulnerability, GIS-Remote sensing model, Weighted Linear combination, Multi-Criteria Evaluation, Abeokuta Metropolis

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Bio-monitoring of Environmental Toxicants using West African Dwarf Goats at Amawzari Mbano, Imo State, Nigeria

Ogbonna P. C., Dikeogu, E. C., Nwankwo, O. U., Kanu, K. C. and Osuagwu E. C.

https://doi.org/10.36263/nijest.2021.01.0279

ABSTRACT
Several health risks have been linked to exposure to environmental toxicants in food consume by man. This study aimed to determine the level of environmental toxicants in goats tended by rural farmers. Fur and blood samples were carefully collected from sixteen (16) goats in open range husbandry (ex situ) at four sites in Amawzari, Imo State, Nigeria. The samples were digested and analyzed separately to determine the concentrations of some environmental toxicants (heavy metals). The concentrations of Pb, Cr, Cd and Ni in blood were 0.01 to 0.05, 0.01 to 0.07, 0.00 to 0.01 and 0.05 to 0.12 mg/kg, while their concentration in fur were 0.02 to 0.03, 0.001 to 0.006, 0.00 to 0.00, and 0.04 to 0.05 mg/kg, respectively. Pearson correlation analysis show very strong positive relationship between Pb in blood and Pb in fur (r = 0.855, p < 0.01) and Ni in blood and Ni in fur (r = 0.811, p < 0.01). The order of abundance of the four heavy metals tested in goat fur and blood is Ni > Cr > Pb > Cd. Based on our findings, the concentrations of heavy metals in blood were higher than its corresponding values in fur. Thus, consumption of meat processed from these metal-contaminated goats and utilization of their blood to manufacture blood meal for pigs and poultry birds will result to bio-magnification of heavy metals in man and animals. Therefore, we recommend that rural farmers should be enlightened on health challenges associated with in situ form of animal husbandry.

Keywords: Environmental toxicants, Blood, fur, West African dwarf goats, Amawzari

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A Qualitative Study of Time Overrun of Completed Road Projects Awarded by the Niger Delta Development Commission in the Niger Delta Region of Nigeria

Ogbeide F. N., Ehiorobo J. O., Izinyon O. C. and Ilaboya I. R.

https://doi.org/10.36263/nijest.2021.01.0269

ABSTRACT
Time overrun of completed road projects awarded by the Niger Delta Development Commission (NDDC) in the Niger Delta Region of Nigeria from its inception in 2000 up to 2015 was studied. Out of 3315 roads awarded, only 1081 roads representing 31.65 percent were completed within the review period. The qualitative study was carried out on randomly selected completed 162 road projects for analysis, and a conceptual model of time series was developed. In developing the regression model, both dependent and independent variables were subjected to normality tests assessed by skewness coefficient, kurtosis value, Jarque-Bera test, residual probability plot, heteroscedasticity test and the variance inflation factor. Also, with knowledge of total road projects awarded by the Commission, it is now possible to predict proportions of roads experiencing schedule overruns.

Keywords: Construction delays, Time overrun, Qualitative studies, Inflation factor

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Effect of Fallowed and Cultivated Land Use Systems on the Composition and Abundance of Soil Macroinvertebrates Assemblage in Uruk Osung Community, Akwa Ibom State, Nigeria

Akpan A. U., Chukwu M. N., Esenowo I. K., Johnson M. and Archibong D. E.

https://doi.org/10.36263/nijest.2021.01.0278

ABSTRACT
This study was to assess the effect of fallowed and cultivated land-use systems on the abundance of soil macroinvertebrates assemblage. Collections of soil samples were carried out fortnightly twice a month for four months. The extraction of soil macroinvertebrates was carried out using Berlese-Tullgren funnel extractor, and elutriation technique. The mean values of 6.93+/-0.25 were recorded for pH, 32.08+/-0.52oC for temperature, 15.60+/-1.22 for moisture content, were recorded for fallowed soil, and 4.43+/-0.16 (pH), 30.95+/-0.19oC (temperature) were recorded for cultivated soil. A total of 17 soil macroinvertebrates species comprising of 11 orders, from four classes were encountered. Out of the 517 individual soil macroinvertebrates encountered, 327 individuals representing four classes were present in the fallow land while 190 individuals representing three classes were present in the cultivated land. The most dominant species in terms of abundance in the fallowed land site included; Cryptotermes sp 67(20.49%) > Blatta sp 56(17.12%) with Hogna sp 1(0.0.30%) the least; while Cryptotermes sp. 79(41.58%) >Lasius sp 30(15.79%) > Lumbricus terrestris 21(11.05%) represents the dominant species in the cultivated soil with Paraponera sp 1(0.53%) the least. Soil temperature showed positive correlation with the abundance of Clitellata (r = 0.851; p < 0.05) and Insecta (r = 0.826; p < 0.05) and Soil pH showed positive correlation with the abundance of Diplopoda (r = 0.911; p ≤ 0.05). In conclusion, it could be deduced from the study that human activities in the cultivated site perturb soil macroinvertebrates community structure which is reflected in the relative abundance of soil macroinvertebrate from the two sampling sites. The results obtained in this study could be a piece of pointing information for the conservation and management of the soil macroinvertebrates giving their functions in balancing agroecosystems.

Keywords: Macro-invertebrates, Fallow land, Cultivated land, Berlese-Tullgren funnel extractor

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