Scientia Africana https://www.ajol.info/index.php/sa <!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:PunctuationKerning /> <w:ValidateAgainstSchemas /> <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid> <w:IgnoreMixedContent>false</w:IgnoreMixedContent> <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText> <w:Compatibility> <w:BreakWrappedTables /> <w:SnapToGridInCell /> <w:WrapTextWithPunct /> <w:UseAsianBreakRules /> <w:DontGrowAutofit /> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><!--[if gte mso 9]><xml> <w:LatentStyles DefLockedState="false" LatentStyleCount="156"> </w:LatentStyles> </xml><![endif]--> <!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0pt; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-GB;} @page Section1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> <!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0pt 5.4pt 0pt 5.4pt; mso-para-margin:0pt; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} </style> <![endif]--><span style="font-size: 10pt; font-family: Arial;" lang="EN-GB"><em>Scientia Africana</em> seeks to encourage communication among scientists all over the world through regular publication of their research findings. The journal publishes results of original research in all aspects of biological, chemical, earth, mathematical, physical and applied sciences including basic medical and engineering sciences. It also publishes review articles, book reviews, research notes and other short communications on all aspects of pure and applied sciences and accepts advertisements in related fields.</span> Faculty of Science, University of Port Harcourt Port Harcourt en-US Scientia Africana 1118-1931 Copyright is owned by the journal Achieving energy efficiency for 5G at base stations level https://www.ajol.info/index.php/sa/article/view/220422 <p>As the era of 5th Generation (5G) networks is dawning, several pertinent issues associated with the improvements that have to be achieved in future communications are attracting increasing research attention. This work, considered achieving energy efficiency for 5G at base stations level. Energy efficiency simply means using less energy to perform the same task thereby, eliminating energy waste. The objective of this paper is to examine the ways of deploying energy efficient hardware at the base stations in order to make the base stations more green energy based. Considering the current energy concerns, base stations in emerging wireless networks range from low-energy BSS to high-energy BSS with entirely different constraints in either case. In view of these extremes, this paper examines the major components behind energy-efficient wireless communication network design during the peak and off-peak traffic periods. It was discovered that the Power amplifier consumes up to 59% of the energy at the base stations. Improving a Power amplifier by bringing linearity could improve the efficiency of the BS and hence reduce the energy crunch at the BS level from 59% to 51%.</p> L.I. Oborkhale C.C. Nwaogu O.A Amadi Copyright (c) 2022-01-26 2022-01-26 20 3 1 10 10.4314/sa.v20i3.1 Evaluation of essential nutrients in edible locusts and grasshoppers in Kano Metropolis https://www.ajol.info/index.php/sa/article/view/220425 <p>The present study was conducted to evaluate the nutritional composition of edible locusts and grasshoppers sold and consumed in Kano&nbsp; metropolis, Northwestern Nigeria. Two species of locusts: (<em>Schistocerca gregaria </em>and<em> Locusta migratoria</em>) and two species of grasshopper (<em>Zonocerus variegatus </em>and<em> Ornithacris turbida</em>) were procured from Rimi market Kano. Proximate, mineral and amino acids compositions of the samples were analyzed using standard methods. The results obtained revealed a significant difference (P≤0.05) in the amount of proteins, fats, ash, carbohydrates and moisture contents. Similar result is found in the mineral compositions in terms of Na, Mg, K, Ca, Cu, Zn and Fe. More so, the amino acid composition of the samples was found to be significantly different (P≤0.05). No significant difference was found in the fibre contents. However, high protein (53.23-67.88%), fats (7.55-18.77%) and carbohydrate contents (10.71-16.01%) were found among the insect samples. Similarly, the amount of essential amino acids such as: threonine, valine, methionine and leucine were higher among the insects. It is therefore concluded that, the edible grasshopper and locust contain significant amount of nutritional components that can be beneficial in combating malnutrition and be incorporated in diet therapy.</p> H.E. Negbenebor O.O. Tinuoye S. Nura Copyright (c) 2022-01-26 2022-01-26 20 3 11 20 10.4314/sa.v20i3.2 Serologic evidence of exposure to Human Immunodeficiency Virus Type 1 and Dengue Virus among patients attending diagnostic Laboratory, Lagos State, Nigeria https://www.ajol.info/index.php/sa/article/view/220443 <p>Reportedly, in co-infection, dengue viral (DENV) replication negatively impacts human&nbsp; immunodeficiency virus type 1 (HIV-1). Reports on this or on&nbsp; people having dual HIV-1/DENV&nbsp; are however, scarce in Nigeria, where both HIV-1 and DENV are endemic. As a preliminary&nbsp; investigation in&nbsp; southwest Nigeria, we hypothesized that a high proportion of individuals&nbsp; presented for laboratory tests have serologic evidence of dual&nbsp; HIV-1/DENV infection. This is a&nbsp; cross-sectional Research Institute-based serologic study; patients attending a specific Clinical&nbsp; Diagnostic Laboratory&nbsp; in Lagos State were enrolled. Plasma samples (n=150) of consenting&nbsp; asymptomatic patients were serially screened for evidence of&nbsp; HIV-1 antibodies using&nbsp; DETERMINETM and UNI-GOLDTM HIV-1/-2 rapid test kits. Only the samples (n=54) confirmed&nbsp; HIV-1 reactive by the latter&nbsp; (and some randomly selected non-reactive samples [n=37]) were&nbsp; tested with ELISA kit for anti-DENV immunoglobulin G (IgG) antibodies. Microsoft&nbsp; Excel and&nbsp; Statistical Package for the Social Sciences were used for statistical analysis. Some participants&nbsp; had detectable HIV-1/DENV antibodies&nbsp; with dual positivity rate of 16.5% [as group-specific&nbsp; point-prevalence rate]. This was independently associated (p=0.04) with marital status as&nbsp; participants who were neither single nor married (categorized as ‘others’) had more than 11&nbsp; times (OR: 11.3) likelihood of being dual seropositive.&nbsp; Mono-positivity of HIV-1 antibody&nbsp; among the 91 participants tested for dual HIV-1/DENV seropositivity was 59.3%;&nbsp; corresponding rate for DENV&nbsp; antibody was 20.9%. As per mono-positivity rates, the likelihood of participants testing positive to HIV-1 antibody was more than 21 times (Odds ratio [OR]: 21.3) that of DENV antibody. In conclusion, 15 participants (16.5%) of this specific group had serologic evidence of dual HIV-1/DENV infection; this we considered low given the endemicity of Nigeria for both viruses. As a subpopulation with unusually high HIV-1 mono-positivity; thelow DENV mono-positivity might be responsible for the low dual HIV-1/DENV positivity.</p> M M. Ojetunde M.O. Alake S.O. Olaniyan G.K. Oyejobi T.J. Olumade N.M. Otuonye W.F. Sule Copyright (c) 2022-01-26 2022-01-26 20 3 21 30 10.4314/sa.v20i3.3 Effect of shade on the germination, growth, and development of two varieties of <i>Abelmoschus esculentus </i>(L.) Moench https://www.ajol.info/index.php/sa/article/view/220447 <p>The effect of shade on the germination, growth, and development of <em>Abelmoschus esculentus</em> (L.) Moench (Okra) was investigated. This experiment was carried out using two varieties of <em>A. esculentus</em> seeds (Kirikoa F1 and Hire varieties) which were replicated 5 times for both under shade and under direct sunlight as growth conditions. The seeds and soil were tested for liability and physicochemical composition, respectively, before the commencement of the work. The parameters assessed following standard procedures on A. esculentus plant were number of leaves, plant height, leaf petiole length, internode, pigments and nutritional composition. The seeds germinated within 3 – 4 days after planting. Among the treatments at ninth week after planting, Kirikoa F1 variety under shade had the highest number of leaves (7.0±1.00), plant height (27.80±5.718 cm), petiole length (7.60±2.408 cm), leaf length (11.30±2.168 cm) and leaf width (10.20±1.924 cm). Also, internode (3.40±1.517 cm) was high at Kirikoa F1 under direct light. Total chlorophyll content of the varieties under light and under shade were: 1.441 mg/g and 1.254 mg/g, respectively for Kirikoa F1 and 0.549 mg/g and 0.938 mg/g, respectively for Hire. Okra under shade had high moisture content (87.36%) when compared to okra under direct sunlight (83.24%) while the reverse was the case for other nutritional composition (carbohydrate, ash content, crude lipid, crude protein and crude fibre). The study showed that Kirikoa F1 variety performed better than the Hire variety during development, and most indices of growth had higher performance under shade condition than under direct light for the okra varieties, respectively.</p> K. Okonwu I.G. Ugiomoh N.V. Ekeji Copyright (c) 2022-01-26 2022-01-26 20 3 31 40 10.4314/sa.v20i3.4 An evaluation of Maastrichtian-Paleocene source rock interval on the western flank of Niger Delta Basin, Nigeria: Implications for hydrocarbon prospectivity https://www.ajol.info/index.php/sa/article/view/220448 <p>Maastrichtian and Paleocene shales recovered from a vertical exploratory well on the western flank of Niger Delta Basin, close to the boundary of the Dahomey (Benin) Basin, were studied for their possible contribution to the hydrocarbon potential of the basin. The organic matter richness, kerogen types, and thermal maturity of the studied shale samples and implications of hydrocarbon generation potential were determined based on results of TOC/Rock-Eval analysis. The Maastrichtian and Paleocene shale samples are characterized by total organic carbon (TOC) values of up to 4.70 wt. % and S2 (hydrocarbon-generating potential) values range from 0.68 to 2.69 mgHC/g rock, indicating poor to fair source potential. The presence of type III and type IV kerogen is indicative of poor-quality organic matter that has the potential to generate gaseous hydrocarbon. This study suggests that the Maastrichtian and Paleocene source rocks on the western flank of the Niger Delta Basin are immature to early mature stage, and could not have generated a commercial amount of hydrocarbon.</p> A.O. Oladotun Copyright (c) 2022-01-26 2022-01-26 20 3 41 52 10.4314/sa.v20i3.5 Concentration of heavy metals and petroleum hydrocarbons in previously remediated sites in Niger Delta, Nigeria https://www.ajol.info/index.php/sa/article/view/220450 <p>This study was aimed at assessing the soil conditions of previously remediated oil spill sites in the Niger Delta region. Ninety-six (96) soil samples were collected over two seasons from remediated sites from three states (Rivers, Abia, and Imo). Gas Chromatographic (GC) Analysis was used in analyzing for Total Petroleum Hydrocarbon (TPH) content while heavy metals analysis for Lead (Pb), Zinc (Zn), Copper (Cu), Chromium (Cr) and Iron (Fe) was done using absorptive spectrophotometric analyses. The data generated was subjected to ANOVA and multiple comparisons, Post-Hoc Tukey HSD test using IBM SPSS version 26.0. Results showed TPH range of 0.85±0.72mg/kg to 1.76±0.42mg/kg in samples from Owaza site in Abia state. Concentration of heavy metals in soil samples was below the standard permissible levels of the World Health Organization and other regulatory bodies such as Department of Petroleum Resources (DPR) intervention values, United States Environmental Protection Agency (USEPA), and Environmental Guidelines and Standards for Petroleum Industry in Nigeria (EGASPIN 2002), accepted values for soil samples. There were no effects of season variation observed. Enrichment factor of (323.20- 508.64) and (298.37-567.26) indicates anthropogenic activities as sources of pollution. The result of the current studies signifies that, the soils of previously remediated sites have safe levels of the contaminants; however, werecommended a regular routine check on the levels of contaminants.</p> D.S. George A.I. Hart L.C. Osuji Copyright (c) 2022-01-26 2022-01-26 20 3 53 72 10.4314/sa.v20i3.6 Application of Grey-Markov model for forecasting Nigeria annual rice production https://www.ajol.info/index.php/sa/article/view/220451 <p>In this paper, Grey system model (GM(1,1)) and Grey-Markov model that forecast Nigeria&nbsp; annual Rice production have been presented. The data used in the research were collected from&nbsp; the archive of Central Bank of Nigeria for a period of Six years (2010-2015). The fitted models showed high level of&nbsp; accuracy. Hence, the models can be used for food security plans of the&nbsp; nation.</p> A. Lawal N.E. Didigwu D.Y. Saidu S.L. Sadiq J. A Khadeejah Copyright (c) 2022-01-26 2022-01-26 20 3 73 84 10.4314/sa.v20i3.7 Assessment of some biochemical indices in red meat tendered with potash and extract of <i>Ocimum basilicum</i> https://www.ajol.info/index.php/sa/article/view/220452 <p>Some changes in biochemical composition in red meat boiled with potash and extracts of <em>Ocimum basilicum</em> was the crux of this research. Fresh beef were divided evenly into 4 groups labeled A-D. Group A was boiled with distilled water, group B was boiled with potash in distilled water, group C was boiled with extract of <em>Ocimum basilicum</em> while group D was boiled with a mixture of potash and <em>Ocimum basilicum</em>. All samples were boiled for fifteen minutes. Samples were taken for analysis at zero hour and after every 48hrs. The samples were stored in a freezer at -4ºC. The pH, malonedialdehyde concentration, acid value, total protein, percentage metmyoglobin and heme iron were determined. The pH values showed significant increase (p&lt;0.05) in red meat boiled with both potash and extracts of <em>Ocimum basilicum</em> from 0 to 144 hours. There was no significant difference (p&gt;0.05) observed in the malondialdehyde concentration and acid value for the duration of the experiment. A significant (p&gt;0.05) decrease in the total protein content was observed after 96 hours in red meat boiled with potash. The results for percentage metmyoglobin content showed a significant difference (P&lt;0.05) and a decrease in red meat boiled with <em>Ocimum basilicum</em> and both potash and <em>Ocimum basilicum</em> after 96 and 144 hours. The results for heme iron concentration showed no significant difference (p&gt;0.05) in red meat boiled with <em>Ocimum basilicum</em> from 0 to 144 hours while an increase was observed in red meat boiled with potash after 96 hours.</p> O.C. Ugbeni B.A. Ibironke D.I. Ikhelegbe-Ojo Copyright (c) 2022-01-26 2022-01-26 20 3 85 94 10.4314/sa.v20i3.8 Assessment of radius of influence of sparging well and biosparging operations in Ozzmukpbu, Zizkwere LGA, Rivers State, Nigeria https://www.ajol.info/index.php/sa/article/view/220454 <p>The capacity to analyse the influence of the operation on the targeted wells is critical to the efficacy of biosparging. Its success varies based on the profile of the targeted region in which the operation is carried out. The Omkpbu investigation was able to establish the impact of the activities as defined by the soil texture, which is clay silt in nature. To establish the ROI inside the research region, a 10m deep sparging well (SW) and 8m deep monitoring wells (MW) were constructed at 1m, 2m, 3m and 5m intervals around the sparging well. The influence of the sparging well became obvious on the 13th, 14th and 15th day of the sparging operations. This resulted in an increase in the dissolve oxygen in the ground water condition across the monitoring wells. In comparism with the baseline data there were massive improvement in the presence of dissolve oxygen in the ground water at an increasing rate as the operations continues. Monitoring well 1, 2, 3 and 4 on the 13th day felt an increased rate of influence at 2.6mg/l, 2.5mg/l, 4.31mg/l and 2.83mg/l as against the base line data of 1.9mg/l, 1.5mg/l, 1.7mg/l and 1.9mg/l respectively. Similarly, there were also an increased influence from data generated on the 13th day as at the 14th day the presence of the dissolve stood at 2.7mg/l, 3.6mg/l, 4.9mg/l, and 3.0mg/l respectively. The 15th day noticed a massive increase in the dissolve oxygen in groundwater as it stood at 4.4mg/l, 6.2mg/l, 6.17mg/l, and 4.78mg/l respectively. Biosparging has a great influence in increasing dissolve oxygen in groundwater which essentially is a major requirement for addressing groundwater contamination.</p> S.O. Tijani A.A. Obafemi A.E. Babalola A.O. Usman Copyright (c) 2022-01-26 2022-01-26 20 3 95 100 10.4314/sa.v20i3.9 Degradation profile and dioxygenase activity of <i>Carnobacterium gallinarum</i> (mt350233) and <i>Enterococcus faecalis</i> (mt345788) isolated from landfill soil in Benin City https://www.ajol.info/index.php/sa/article/view/220455 <p>Landfill is a potential microbial hub of hydrocarbon (HC) degrading bacterial population owing to nutrient availability and continuous enrichment by organic materials. The degradation and dioxygenase activity of <em>Carnobacterium gallinarum</em> and <em>Enterococcus faecalis</em> isolated from landfill soil in Benin City was investigated. Soil samples were collected from a Government approved landfill in Benin City at a depth of 0 to 10 cm. Standard microbiological and molecular methods were followed for the isolation and characterization of bacterial population. Bacterial isolates were standardized for degradation using spectrophotometer optical density (OD) 0.08 at 600 nm (equivalent to 1×10<sup>8</sup>cfu/ml). The gas chromatography with flame ionization detector (GC-FID) method was used to determine the total petroleum hydrocarbon (TPH) of waste engine oil (WEO) containing samples. The spectrophotometric methods were used for the assay of catechol 1,2-dioxygenase (C12O) and catechol 2,3-dioxygenase (C23O) activity. The result of the 16S rRNA analyses of the bacterial isolates confirmed the identity of <em>Carnobacterium gallinarum</em> as 98.71 % and <em>Enterococcus faecalis</em> as 100 %. The degradation profile of <em>Carnobacterium gallinarum</em> and <em>Enterococcus faecalis</em> at varied concentrations (20, 40, 60, 80 and 100 mg/L) of WEO showed significant decline in optical density (OD) values from day 1 to day 7. The decline in OD is an indication of utilization of Polycyclic Aromatic Hydrocarbons (PAHs) present in the WEO. The result of the gas Chromatography with Flame Ionization Detector (GC-FID analyses) of degraded WEO containing samples revealed the absence of low molecular weight and high molecular weight PAHs after the 7-days degradation study. The presence of HC degrading enzyme in the bacterial isolates was confirmed by the production of C12O and C23O as a result of the formation of cis, cis muconic acid and 2-hydroxymuconic semi-aldehyde respectively. This study revealed that the landfill soil is a potential natural microcosm for WEO degrading bacteria and possesses biologically active HC degrading bacteria population such as <em>Carnobacterium gallinarum</em> and <em>Enterococcus faecalis</em>.</p> F.I. Okolafor J.O. Osarumwense F.O. Ekhaise Copyright (c) 2022-01-26 2022-01-26 20 3 101 118 10.4314/sa.v20i3.10 Production and optimization of lactic acid using <i>Chlorella vulgaris</i> as a source of fermentable sugar https://www.ajol.info/index.php/sa/article/view/220456 <p>The use of plant waste product for maximum sustainability has led to the search for bio based raw material such as <em>Chlorella vulgaris</em> which can make a tremendous contribution on the ecological and economical production of different organic acids like lactic acid. This study aimed to evaluate the enzymatic and or acidic hydrolysis of <em>Chlorella vulgaris</em> cell wall Intercellular starch as a source of fermentable sugar for lactic acid production. Lactic acid was produced through acid hydrolysis, enzyme hydrolysis and a combination of acid and enzyme hydrolysis of four different substrates. Each of the substrate was inoculated with a lactic acid bacterium (<em>Lactobacillus plantarum</em>) and a fungus (<em>Rhizopus oryzae</em>) while acid/enzyme hydrolysis was inoculated with mixed culture of the organism within a retention period of tendays.&nbsp; Results showed that the physico-chemical properties of <em>C. vulgaris</em> had a total carbohydrate of 17.4% and a reducing sugar of 24.0µg/ml. According to treatment, <em>C. vulgaris</em> had the highest reducing sugars (6.4 ± 0.2) and (4.4 ± 0.3) with <em>Lactobacillus Enzyme Hydrolysis (LEH) </em>and<em> Rhizopus Enzyme Hydrolysis (REH</em>) treatments, respectively indicating that <em>C. vulgaris</em> was the most hydrolyzed sample. Results of the optimization of various responses showed that using Corn Steep Liquor (CSL), REH day 2 treatment for fermentation at 370C for 48h were best combinations that yielded the optimal of Y1=0.249, Y2= 5.461 and Y3=33.704, respectively with a desirability of 0.619. The results indicated <em>Chlorella vulgaris</em> produced the highest lactic acid of about 20% signifying that its biomass contains high source of carbohydrate accessible for lactic acid production.</p> O.K. Agwa C.A. Chukwunweike F.S. Ire Copyright (c) 2022-01-26 2022-01-26 20 3 119 140 10.4314/sa.v20i3.11 Synthesis and characterization of a high surface area activated carbon derived from cassava peels waste by KOH activation https://www.ajol.info/index.php/sa/article/view/220458 <p>This work presents the synthesis of activated carbon, a very important material with lots of use cases in textile, food industries and even in energy storage as an electrode material in supercapacitor development. Abundantly available cassava peels was used as a raw material for the production of the activated carbon by adopting the chemical activation approach which utilized KOH as activating agent. The activation was carried out at 800<sup>0</sup>C in a tubular furnace. Scanning electron micrographs (SEM) showed that a highly porous carbon structure was achieved with high specific surface area of 828m<sup>2</sup>g<sup>-1</sup>as evident from the BET results. Raman spectrophotometer analysis showed that the prepared activated carbon was highly graphitized as seen from the G peak. The existence of mesopores and micropores was confirmed by the N<sub>2</sub> adsorption/desorption analysis which also revealed the presence of a hysteris loop and a P/P<sub>0</sub>=0.45 value.</p> T.E. Amakoromo O.E. Abumere J.A. Amusan Copyright (c) 2022-01-26 2022-01-26 20 3 141 148 10.4314/sa.v20i3.12 Characterization of chitosan from <i>Rhynchophorus phoenicis</i> and synthesis of its alumina nanocomposite https://www.ajol.info/index.php/sa/article/view/220459 <p><em>Rhynchophorus phoenicis</em>, found in the tropical regions of Africa where it is regarded as a pest was used to synthesize chitosan and alumina-chitosan nano-composite. The synthesized Chitosan and alumina-chitosan nano-composite were characterized using instrumental methods of analysis which include Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Scanning Electron Microscope (SEM). FTIR reveals the existence of OH stretching vibration –NH stretching, NH bonding, vibration of methylene C-H bonding, O=C=O stretching, C-N bonding stretching and CO stretching vibration at 3842.33 cm<sup>-1</sup>, 3402.54 cm<sup>-1</sup>, 3286.81 cm<sup>-1</sup>, 2939.61 cm<sup>-1</sup>, 1527.67 cm<sup>-1</sup>, 1303.92 cm<sup>-1</sup> and 1041.60 cm<sup>-1</sup> respectively. The scanning electron micrograph proves that the chitosan has large particles that are regular with paltry pores while alumina-chitosan nano-composite has fairly small particles and porous surface with significant pores. X-ray diffractogram showed a distinct stretch at 22<sup>o</sup>; 16<sup>o</sup> and 25<sup>o</sup>; 17<sup>o</sup> for chitosan and alumina-chitosan nano-composite. The characterization of the products confirmed that the synthesis of chitosan and alumina-chitosan nano-composiote was effective.</p> C.I. Osu H.C. Ugwu G.N. Iwuoha Copyright (c) 2022-01-26 2022-01-26 20 3 149 160 10.4314/sa.v20i3.13 Investigation of the relationship between f<sub>0</sub>f2 and the TEC using single station neural network models https://www.ajol.info/index.php/sa/article/view/220460 <p>The relationship between the ionospheric critical plasma frequencies (f0F2) and GNSS-TEC (Global Navigation Satellite System –Total Electron Content) measurements was investigated using an artificial neural network method. About 20 pairs of ionosonde-GNSS receiver stations from 2000 to 2016 were used. Results from this work indicate that the relationship between f<sub>0</sub>F2 and TEC is mostly affected by the seasons, followed by the level of solar activity, and then the local time. Geomagnetic activity was the least significant of the factors investigated. The relationship between f<sub>0</sub>F2 and TEC was also shown to exhibit spatial variation; the variation is less conspicuous for closely located stations. Single station models predicted the f<sub>0</sub>F2 more accurately at their particular localities and clearly overestimated values of the f<sub>0</sub>F2 ionosonde observations when used at different localities. This finding indicates that model predictions are better (in terms of reduced prediction errors) for the stations for which they are developed than for a different station. Our result visibly point out that models developed for a particular station cannot be effectively applied in another station located farther apart in space. The new approach described in this study represents an important contribution in space weather prediction.</p> V. Otugo C.U. Okujagu S. Onwuneme Copyright (c) 2022-01-26 2022-01-26 20 3 161 172 10.4314/sa.v20i3.14 Evaluation of hydrocarbon potential of shale outcrops in the flanks of Anambra Basin https://www.ajol.info/index.php/sa/article/view/220462 <p>The research aim is to determine the organic productivity and hydrocarbon potential of the exposed shale lithology along Uzebba road and Bawa hills near Auchi, Southwest Nigeria.Twenty two (22) shale samples were acquired from the study area; twelve (12) from the outcropping section along Uzebba road, and the remaining ten (10) samples obtained from Bawa hills. The samples were then subjected to organic geochemical analysis using Total Organic Carbon (TOC) and Rock Eval Pyrolysis to evaluate the organic enrichment, organic quality and thermal maturity espectively.Total Organic Carbon (TOC) content of the twentytwo samples ranges from 3.42 – 4.88 wt. %, affirming a high organic enrichment. Shale samples from Uzebba segment and Bawa hills falls within the Type I and Type II Kerogen class respectively. The former is indicative of immature – sub mature organic matter with no hydrocarbon formation prospect whilst the latter exhibits great hydrocarbon (oil) generation potential Thermal maturation assessment for both samples apparently ranges from immature to mature organic matter. From the Rock-Eval pyrolysis result, all the twenty-two (22) samples were confirmed to be organically enriched. However, the type I kerogen of Bawa at favourable geothermal gradient can potentially serve as a suitable source rock for petroleum generation.</p> P.R. Ikhane O.C. Atewolara J.O. Coker A.O. Alaka O.O. Oyebolu Copyright (c) 2022-01-26 2022-01-26 20 3 173 192 10.4314/sa.v20i3.15 Equilibrium and kinetic studies of the dehydration of ethyl alcohol-water mixture via locally synthesized activated starch https://www.ajol.info/index.php/sa/article/view/220463 <p>Batch kinetic process was employed in the evaluation of the dehydration of ethyl alcohol-water mixture via locally synthesized activated starch from cassava and maize. The equilibrium data generated were analyzed using adsorption isotherm and kinetic mechanism model equations. Results showed that the optimum concentration of 74.07% was obtained when 4g of modified cassava starch was contacted with 70ml of ethyl alcohol of initial concentration 69.72% at a contact time of 20min where the volume of ethyl alcohol recovered was 65ml. The maize starch could only achieve 72% optimum concentration when same 4g of modified maize starch was used with 70ml of ethyl alcohol with an initial concentration of 68.15%, at a contact time of 20 min where 60 ml of ethyl alcohol was recovered. The adsorption isotherm was studied using two well-known models; Langmuir and Freundlich. Although results showed that the adsorption process obeyed both models, however, the Freundlich model gave a better fit with an R<sup>2</sup> value of 0.984 as against 0.974. The kinetic study on the other hand showed that the adsorption process obeyed the pseudo-second order.</p> C.A. Idibie E. Omo-Udoyo J. Fielami Copyright (c) 2022-01-26 2022-01-26 20 3 193 202 10.4314/sa.v20i3.16 Fluid-structure interaction: Advances on erectile functionality https://www.ajol.info/index.php/sa/article/view/220464 <p>In this work the interaction between the blood and the penile structures was treated in order to have an insight into erectile functionality. Coital consummation and, maybe, its concomitant tendency to procreate is only attainable when there exists a fluid-structure synergy. Remarkably, hemodynamic influence is the basis of the behaviour of the penile ‘utensils’ towards such consummation. The blood flow that induces penile engorgement that precedes vaginal intromission results in both tunical and vascular deformation, as was shown theoretically in this paper. The equations that govern blood flow and those that govern the penile structures’ response are derived. One of the results is the equation that furnishes the axial length of a penile shaft under axial displacement by using some tunical characteristics. Of much interest in erectile functionality is the concept of penile buckling. This was given attention here. Contrary to some insinuations occasioned by the treatment of the penile ‘shaft’ as a column subjected to axially compressive force that buckles under further application of a force, which was reported here, this work sees penile tissue detumescence resulting from the withdrawal of a force as the basis of penile axial buckling.</p> F.E. Nzerem H.C. Ugorji Copyright (c) 2022-01-26 2022-01-26 20 3 203 220 10.4314/sa.v20i3.17 Ethno medicine “The uses of ‘Aju-Mbaise’ in post partum care https://www.ajol.info/index.php/sa/article/view/220469 <p>A survey of the plants used in post partum care in Mbaise and its environs popularly known as Aju Mbaise was carried out. A series of unstructured interview was used to elicit information from about 36 participants made up of the old women and herbalists who dispense the wraps especially that are used in post-partum treatment. This work aimed at unraveling and documenting the plants that are found within the wrap for post-partum care and on the claim for its potency for treatment in parturition. The wrap is prepared from different plant parts which include leaves, flowers, fruits, twigs, barks, roots and even buds and administered as a decoction. At the end it was found that the wraps had plants drawn from 13 different families. These families include <em>Acanthaceae, Menispermataceae, Ceasalpinoideae, Commelinaceae, Annonaceae, Convulvulaceae, Leguminosae, Euphorbiaceae, Sapotaceae, Asparagaceae </em>and<em> Myrtaceae</em>. The range of treatments include high blood pressure, detoxification, oedema, erectile dysfunction and most especially in post-partum treatment. The plants from these families are wrapped together in one pad. In conclusion ethno-botanical survey revealed that decoction of ‘Aju Mbaise’, enhances quick recovery after child birth.</p> I.G. Ugiomoh M. Mbalewe Copyright (c) 2022-01-26 2022-01-26 20 3 221 230 10.4314/sa.v20i3.18 Petrophysical analysis of well data for clastic reservoir evaluation and determination of the invaded zone effect: A case study of a field in the onshore Niger Delta, South-South, Nigeria https://www.ajol.info/index.php/sa/article/view/220475 <p>Two reservoirs domiciled in a well have been analysed in this study in order to obtain the quantitative reservoir properties. These quantitative reservoir properties are essential not only for well development and optimization but also for accurate decision-making prior to reservoir exploitation and production. A suite of composite logs comprising the caliper log, gamma-ray (GR) log, density log, resistivity logs and sonic transit time logs obtained from a field in the onshore Niger Delta was used for the petrophysical analysis. From our quantitative results, Reservoir 1 has the potential to produce oil and gas with a total hydrocarbon saturation of 81%. However, due to the invaded zone effect on the reservoir potential, the total hydrocarbon fluid has been partitioned into moveable hydrocarbon of 65% saturation and immoveable hydrocarbon of 16% saturation. This resulted from the mud filtrate invasion of the radially shallow zone which displaced the original fluid while the undisplaced hydrocarbon fluid remained in the pore spaces of the reservoir. The porosity of the reservoir sand is 33% and its effective porosity is 32.5%. The high effective/interconnected porosity and clean nature of the sand which is due to the extremely small volume of shale present in the sand (just 1.0%) clearly shows that the reservoir is highly porous, permeable and producible.The net pay of the reservoir (represented by the thickness TH in Mesh 1) could not be quantitatively determined due to lack of depth information on the logs. The second reservoir (Reservoir 2) has a total hydrocarbon saturation of 94.8% and water saturation of just 5.2%. The total hydrocarbon saturation is partitioned into 82.8% moveable hydrocarbon saturation and 12% immoveable hydrocarbon saturation which resulted from the invaded zone effect. The porosity of the reservoir was determined at 33% and its effective porosity at 32.5%. Again, the high effective/interconnected porosity and clean nature of the sand arising from the extremely small volume of shale present in the sand (0.4%) is a clear indication that the second reservoir is also highly porous, permeable and producible. The net pay of Reservoir 2 (represented by the thickness TH in Mesh 2) is higher compared to Reservoir 1 but could not be evaluated due to absence of depth values on the logs. In the final analysis, the overall results show that the reservoirs are commercially favourable and have the potential to pay back.</p> R.C. Nwankwo Copyright (c) 2022-01-26 2022-01-26 20 3 231 240 10.4314/sa.v20i3.19 A survey on global cyber-warfare and Nigerian’s cyber defensive strategy: A way forward https://www.ajol.info/index.php/sa/article/view/220478 <p>With two years having passed since the infamous cyber conflict between Estonia and Russia, on 08 May 2009 international society still lacks a coherent set of principles, rules, and norms governing state security and military operations in cyberspace. For parties committed to promoting the cause of peace and stability in a multipolar world, this is a troubling notion since history shows that the likelihood of a new arms race is high when disruptive technologies dramatically alter the means and methods of war. As more nations aspire to project national power in cyberspace, a new digital arms race appears to be imminent if not already upon us. Thus, there is a central question confronting international society and Nigeria in cyberspace: What steps can be taken both today and into the future to forestall a major arms race and interstate competition in cyberspace? In order to begin addressing this complex question from the perspective of the Euro-Atlantic Community, this paper discusses both the challenges and opportunities of regulating 21st century cyber warfare. The paper is divided into sections, which examine the evolution of the laws of armed conflict (LOAC) since the late 19th century, how the LOAC apply to cyber warfare as viewed primarily from a US perspective (since US scholars have dominated the international regime discourse thus far), and the historical facts on cyber warfare. The Nigerian roles in cyber defense strategy and what is needed to be done to meet up with a global regime for cyber warfare in respect of cyber defense are also highlighted. Global cyber strategies, threats/attacks, and types of cyber weapons d</p> S.D. Usman S.B. Junaidu A.A. Obiniyi M.B. Bagiwa Copyright (c) 2022-01-26 2022-01-26 20 3 241 256 10.4314/sa.v20i3.20