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Item Open Access Structural stability and carbohydrate contents of an ultisol under different management systems(Elsevier Science B. V., 2001) Adesodun, J. K.; Mbagwu, J. S. C.; Oti, N.An understanding of the dynamics of soil carbohydrate pools is necessary for assessing the impact of organic residue management in organic matter build up and structural stability in tropical ecosystems. The objectives of this study were to evaluate temporal changes in aggregate stability and cold water-soluble, hot water-soluble and acid-soluble carbohydrate fractions of a sandy soil under different organic residue management practices. The soil is an Nkpologu sandy clay loam (fine loamy, kaolinitic, isohyperthermic, typic kandiustult) at Nsukka in southeastern Nigeria. In July 1995, it was incorporated with complete fertiliser (N:P:K ¼ 12:12:17 at 480 kg/ha) (F); rice mill wastes (RW, 10 t/ha); RW þ F; poultry manure (PM, 10 t/ ha) and RWð5t=haÞþPMð5t=haÞ up to the 0–20 cm depth. A control, tilled up to the 0–20 cm depth, was also included Surface soil samples (0–20 cm), collected at 3, 6 and 12 months after residue applications were used to measure changes in aggregate stability by mean weight diameter (MWD), total OC and carbohydrate pools. In all treatments MWD increased whereas the concentrations of acid-soluble, hot water-soluble and cold water-soluble carbohydrates decreased with sampling time. Also irrespective of the type of amendment, the carbohydrate concentrations at each sampling period varied in the order, acid-soluble > hotwater-soluble > coldwater-soluble. Aggregate stability correlated very poorly with all the carbohydrate fractions and OC. The correlation coefficient values were rather low and did not mean much in the physical interpretation of these results. This shows that these carbohydrate pools were not very effective in stabilizing the soil aggregates.Item Open Access Influence of halide ions on the inhibitive effect of Congo red dye on the corrosion of mild steel in sulphuric acid solution(Elsevier B. V., 2004) Oguzie, E. E.The inhibitive effect of congo red dye (CR) on mild steel corrosion in sulphuric acid solution was studied at different temperatures using gravimetric techniques. The influence of halide additives namely: KCl, KBr and KI on the inhibition efficiency of CR was also investigated. Inhibition efficiency increased with CR concentration but decreased with rise in temperature. Corrosion activation energies of 82.98 and 96.92kJmol−1 were observed in the absence and presence of CR, respectively. The observed corrosion data suggest that inhibition of mild steel corrosion is due to physical adsorption of the CR molecules on the metal surface, which follow Flory–Huggins isotherm. Inhibition antagonism and synergism were respectively observed at 30 and 60°C on addition of halide salts to inhibited systems containing CR. The inhibition efficiency of CR in the presence of halides increased with rise in temperature and corrosion activation energy in these systems decreased to 40.63kJmol−1. These observations indicate a chemical adsorption mechanism, thus suggesting that the halide ions reversed the mechanism of CR adsorption within the concentration range studied. The calculated values of heat of adsorption confirm physisorption and chemisorption mechanisms respectively for CR adsorption in the absence and presence of halidesItem Open Access Inhibition of mild steel corrosion in sulphuric acid using indigo dye and synergistic halide additive(Elsevier Ltd, 2004) Oguzie, E. E.; Unaegbu, C.; Ogukwe, C. N.; Okolue, B. N; Onuchukwu, A. I.Gravimetric method was used to study the inhibitory properties of indigo dye during corrosion of mild steel in aerated sulphuric acid solutions at 30–50°C. The effect of addition of halide salts KCl, KBr and KI was also investigated. The corrosion rates in all systems studied increased with rise in temperature. The inhibition efficiency of indigo dye increased with concentration and synergistically increased on addition of halide salts. Temperature studies revealed increased inhibition efficiency at higher temperatures, which is suggestive of chemisorption mechanism. The inhibitor adsorption characteristics were approximated by Frumkins isotherm and Flory–Huggins isotherm. Activation energy for Fe dissolution in sulphuric acid was observed to reduce from 54.6kJmol−1 in the uninhibited system to 34.9kJmol−1 in the inhibited systemItem Open Access Inhibitory mechanism of mild steel corrosion in 2M sulphuric acid solution by methylene blue dye(Elsevier Ltd, 2005) Oguzie, E. E.; Onuoha, G. N.; Onuchukwu, A. I.Methylene blue dye (MB) was investigated as a corrosion inhibitor for mild steel in 2M sulphuric acid solution using gravimetric and thermometric techniques. The inhibition efficiency of MB increased with concentration and synergistically increased in the presence of the halide additives, namely KCl, KBr and KI. The trend of inhibition efficiency with temperature suggests that inhibitor molecules are physically adsorbed on the corroding metal surface at lower concentration (0.01–0.5mM), and chemically adsorbed at higher concentration (1.0–5.0 mM). These results were further corroborated by kinetic and activation parameters for corrosion and adsorption processes evaluated from experimental data at the temperatures studied. MB was found to obey Langmuir and Frumkin adsorption isotherms in the concentration range investigatedItem Open Access The impact of urban run-off on Ogbor River(U. P., 2005) Atulegwu, Patrick UzoijeImpact of urban run-off on Ogbor River in Aba metropolis has been studied. The run-off contains toxic chemical, heavy metals and suspended solids. Water samples were collected from three discharged points in the months of May to September. The results of the analysis of the samples show high-level concentration of lead, iron, cadmium, cyanide and chromium (1.7mg/l, 5.52mg/l, 1.47mg/l, 2.44mg/l and 1.31mg/I respectively). However, the water sample of the slaughter house,and the industrial effluents are free from heavy metals. In addition, the water quality of the downstream location of the river shows an appreciable reduction of the concentration of the heavy metals probably due to dispersion effect. The presence of this pollution in water is hazardous to health. Ballasted flocculation technology can be used to reduce .Item Open Access Application of soil quality morphological index in assessing soil health of arable farms on isophyperthermic ruptic-alfic dystrudepts in Owerri, Southeastern Nigeria(R. Durson Associates, 2006) Onweremadu, E. U.; Opara, C. C.; Oti, N. N.; Uozoho, B. U.; Ibe, A. E.; Tom, C. T.; Onwubiko, N. C.; Nwokeji, E. M.Soil quality morphological index (SQMI) was used to assess soil health of arable farms on soils along Otamiri River in Owerri, Nigeria. Sampled points were identified based on physiography and linked using a transect. Three minipedons were dug at equal inter minipedal distance of 35 metres and sampled. Results showed that soils on a levee had the best quality (SQM1 = 3. 52), followed by Terace (SQMI = 2.83), Backswamp (SQMI 2: 75) and least in Upland soils (SQMI =2.64). Soil quality has a good relationship with organic matter (r = 0.92; r2 =0.84; 1 r2— 0.16; P-0.05). Results of soil properties were used to classify soils of the site as Isohyperthermic Ruptic-Alfic Dystrudepts (USDA. Soil Taxonomy).Item Open Access Studies on the inhibitive effect of Occimum viridis extract on the acid corrosion of mild steel(Elsevier Ltd, 2006) Oguzie, Emeka E.Corrosion inhibition of mild steel in 2M HCl and 1M H2SO4 by leaf extracts of Occimum viridis (OV) was studied using the gasometric technique at temperatures of 30 and 60°C. The results indicate that the extracts inhibit the corrosion process in both acid media and inhibition efficiency increased with concentration. Synergistic effects increased the inhibition efficiency in the presence of halide additives namely KCl, KBr, KI. Temperature studies revealed a decrease in efficiency with rise in temperature and corrosion activation energies increased in the presence of the extract, probably implying that physical adsorption of cationic species may be responsible for the observed inhibition behaviour. Comparative analysis of the inhibitor adsorption behaviour in 2M HCl and 1M H2SO4 as well as the effect halide additives suggest that cationic species may not be the only constituents responsible for the inhibiting action of the extractItem Open Access Assessment of multi-band capabilities in the detection of build-up area in Northwest Nigeria(U. P., 2006) Njoku, D. John; Okoli Chidi G; Atulegwu P. Uzoije; Iwuji, Martin CCorrected and uncorrected SPot XS Imagiries are used to achieved comparative assessment of build - up area land use and land use cover classes in Northwest Nigeria. The build -up environment showed on both imageries. The PAVM was used to determine the ability of data sets to produce similar results over the area . Result indicate a low PAVM value for the tertiary level urban land use and land cover classes except the commercial area. vacant lands, industrial area and open spaces show zero values. The results have implications on the planning of urban and natural resources development in the ecologically fragile region of Northwestern NIgeria.Item Open Access Underground water quality of rock mining in Ishiagu, Ebonyi State, Nigeria(2006-06) Obiekezie, S. O.; Okereke, J. N.; Anyalogbu, E.; Okorondu, S. F.; Ezejiofor, T. I. N.Physicochemical and bacteriological analysis of underground water of Crush Rock mining pit in Ishiagu, Ebonyi State Nigeria were carried out to determine the pollution level and the potability of the groundwater due to mining and human activities. The results were compared with standards for water pollution and World Health Organization for drinking water. The results showed that total dissolved solids (TDS), total alkalinity, calcium and sodium, which had concentration ranges of 126-986ppm, 200.18-615.55ppm, 7.8- 30.10ppm and 64-88ppm respectively, were above standards. However, the mean concentration of dissolved oxygen (DO) (1.2-3.20ppm) was below the standard. Other parameters measured were found to be within the permissible acceptable standard. Pseudomonas, Chromabacterium, Bacillius, Escherichia, Staphylococcus, Flavobacterium, Micrococcus, Citrobacter, and Achromobacter species were identified as the major bacteria isolated from the underground water. The study revealed that the underground water from Crush Rock mining pit in Ishiagu Ebonyi State, Nigeria require some chemical and physical treatment as it is unsafe for human consumption.Item Open Access Bacterial quality of rainwater in selected communities in Imo State, Nigeria(UP, 2006-06) Okereke, J. N.; Obasi, K. O.; Obiekezie, S. O.; Okechukwu, R. I.Muitas comunidades rurais do estado de Imo, Nigéria oriental, não têm acesso à água potável, sendo que a á gua da chuva tem sido sua principal fonte. Neste estudo, foram determinados os níveis bacterianos da á gua da chuva em três comunidades, Umunumo, Egbema e Ihiagwa. As amostras foram colhidas direta mente de telhados de zinco, telhados de sapê e telhados de amianto em diferentes períodos de chuva, mês de maio (começo das chuvas), mês de julho (pico das chuvas) e outubro (final das chuvas). A água acumulada de telhados de zinco da comunidade de Umunumo também foi examinada. O nível bacteriano foi alto no começo das chuvas nas amostras coletadas nos telhados de sapê, sendo seu maior valor em Egbema (7,4 x 103 cfu/100 ml). Os níveis de coliformes totais e coliformes fecais ( °6± ² ³«´ µG¶G² ³ ¶G·•² ¸ ¹ ) tiveram picos no começo das chuvas, 10 – 36 cfu/100 ml e 1 – 5 cfu/100 ml, respectivamente. Também nos reservató rios subterrâneos a contagem total de bactérias, coliformes totais e coliformes fecais totais foi muito elevada. As amostras estudadas dos meses de julho (pico) e outubro (final) de todas as comunidades estavam dentro do padrão de qualidade de água potável da OMS. Usando um modelo estatístico (para a = 0.05), a hipó tese nula foi rejeitada para os métodos e o período da coleta, enquanto que o local de coleta foi aceito. Portanto, apenas o período e o método de coleta das águas das chuvas afetam os níveis bacterianosItem Open Access Corrosion inhibition of aluminium in acidic and alkaline media by Sansevieria trifasciata extract(Elsevier Ltd, 2007) Oguzie, E. E.The inhibitive action of leaf extracts of Sansevieria trifasciata on aluminium corrosion in 2 M HCl and 2 M KOH solutions was studied using the gasometric technique. The results indicate that the extract functioned as a good inhibitor in both environments and inhibition efficiency increased with concentration. Synergistic effects increased the inhibition efficiency in the presence of halide additives. Temperature studies revealed a decrease in efficiency with rise in temperature and corrosion activation energies increased in the presence of the extract. A mechanism of physical adsorption is proposed for the inhibition behaviour. The adsorption characteristics of the inhibitor were approxi mated by Freundlich isothermItem Open Access Effect of 2-amino-3-mercaptopropanoic acid (cysteine) on the corrosion behaviour of low carbon steel in sulphuric acid(Elsevier Ltd., 2007) Oguzie, E. E.; Lia, Y.; Wang, F. H.The effect of cysteine (cys) on the corrosion of low carbon steel (LCS) in sulphuric acid solution was investigated using electrochemical and scanning electron microscopy (SEM) techniques. Electrochemical impedance spectroscopy (EIS) results reveal that the presence of cys at low concentrations (0.1–0.5mmolL 1) promoted the LCS corrosion process, whereas an inhibiting effect was observed at higher concentrations (1.0–5.0 mmolL 1), which was enhanced on deaeration of the test solution. Polarization results revealed that cys actually inhibited the cathodic process at all concentration but exerted a stimulating effect on the anodic metal dissolution reaction. Despite the cathodic inhibiting effect, the polarization resistances at low cys concentrations were less than that in the blank acid. This suggests that the anodic reaction was the predominant influence determining the corrosion rates in the presence of cys. This has been discussed vis-` a-vis the catalytic effect of the Fe–cys complex, which turns the Fe surface more electrochemically activeItem Open Access Corrosion inhibition and adsorption behavior of methionine on mild steel in sulfuric acid and synergistic effect of iodide ion(Elsevier Inc., 2007) Oguzie, E. E.; Li, Y.; Wang, F. H.The corrosion inhibition of mild steel in sulfuric acid by methionine (MTI) was investigated using electrochemical techniques. The effect of KI additives on corrosion inhibition efficiency was also studied. The results reveal that MTI inhibited the corrosion reaction by adsorption onto the metal/solution interface. Inhibition efficiency increased with MTI concentration and synergistically increased in the presence of KI, with an opti mum[KI]/[MTI] ratio of 5/5, due to stabilization of adsorbed MTI cations as revealed by AFM surface morphological images. Potentiodynamic polarization data suggest that the compound functioned via a mixed-inhibition mechanism. This observation was further corroborated by the fit of the experimental adsorption data to the Temkin and Langmuir isotherms. The inhibition mechanism has been discussed vis-à-vis the presence of both nitrogen and sulfur atoms in the MTI moleculeItem Open Access Agricultural land use in peri-urban communities in Nigeria: A review(Tapas Institute of Scientific Research and development, 2007-04) Ajaero, J. O.; Matthews-Njoku, E. C.; Ehirim, N. C.This paper reviewed the emerging problems of agricultural land use in Nigeria outlying communities. The outlying communities are known to be major sources of agricultural products to nearby urban areas. However, agricultural activities are under the threat of being abandoned due to the transfer of arable land other uses apart from agriculture. This was found to be due to the increased economic value (price) of land, which makes land a source of immediate income to escape chronic poverty. The emerging scenario is the replacement of traditional communal landholding by individual arrangement in the outlying agrarian rural communities to facilitate permanent alienation so that individuals can dispose of their farm lands to other uses. This would have the effects of forcing a significant population engaged in agriculture to the unemployment market, the emergence of landless farmers and compound problem of resource accessibility by disadvantaged groups like women farmers. It has also led to the increase in land rates for agricultural purposes and unabated decrease in farm size among farmers. The paper suggests that farming layouts should be mapped out and given equal attention as accorded to industrial and residential areas by urban development authorities. It concludes that extension service activities should be directed toward the dissemination of innovations like vegetable and small ruminant production, which does not require large expanse of land and compatible with land situations in these areas.Item Open Access Microbial flora of oil-spilled sites in Egbema, Imo State, Nigeria(Academic Journals, 2007-04-16) Okereke, J. N.; Obiekezie, S. O.; Obasi, K. O.The microbial flora of areas with and without oil spillage within the Egbema oil field in Ohaji/Egbema of Imo State was determined by standard microbiological methods. Preliminary results show moderate biological activities in both environments studied. The average microbial population of the area with oil spillage was 3.08 x 107 cfu/g, while that of the adjoining environment was 3.14 x 107 cfu/g for bacteria. Fungi population was of the order 106. The microorganisms isolated were identified to species level. Majority of the microorganisms were true bacteria. Actinomycete species were also found. In general, species difference between the two environments tended to be considerably significant. Since species and microbial population differences in soils are directly proportional to the availability of carbon source (nutrient), soil acidity, oxygen level and other factors, the significant variation in species and slight difference in microbial population observed are indicative of the effects of oil spillage on microbial flora of a given area.Item Open Access Evaluation of the inhibitive effect of some plant extracts on the acid corrosion of mild steel(Elsevier Ltd, 2008) Oguzie, Emeka E.Corrosion inhibition of mild steel in 2M HCl and 1M H2SO4 by extracts of selected plants was investigated using a gasometric technique at temperatures of 30 and 60°C. The studied plants materials include leaf extracts Occimum viridis (OV), Telferia occidentalis (TO), Azadirachta indica (AI) and Hibiscus sabdariffa (HS) as well as extracts from the seeds of Garcinia kola (GK). The results indicate that all the extracts inhibited the corrosion process in both acid media by virtue of adsorption and inhibition efficiency improved with concentration. Synergistic effects increased the inhibition efficiency in the presence of halide additives. Inhibition mechanisms were deduced from the temperature dependence of the inhibition efficiency as well as from assessment of kinetic and activation parameters that govern the processes. Comparative analysis of the inhibitor adsorption behaviour in 2M HCl and 1M H2SO4 as well as the effects of temperature and halide additives suggest that both protonated and molecular species could be responsible for the inhibiting action of the extractsItem Open Access Corrosion inhibitive effect and adsorption behaviour of hibiscus sabdariffa extract on mild steel in acidic media(UP, 2008) Oguzie, E. E.The inhibiting action of the calyx extract of Hibiscus sabdariffa on mild steel corrosion in 2 M HCl and 1 M H2SO4 solutions was assessed using a gasometric technique. The results demonstrate that Hibiscus sabdariffa extract suppressed the corrosion reaction in both acid media and inhibition efficiency increased with extract concentration with slightly higher values obtained in 1 M H2SO4. Synergistic effects increased the efficiency of the extract in the presence of halide additives. Adsorption characteristics of the extract were approximated by the Langmuir isotherm. The inhibition mechanisms, estimated from the temperature dependence of inhibition efficiency as well from kinetic and activation parameters show that the extract functioned via mixed inhibition mechanism. It is suggested that molecular as well as protonated organic species in the extract contribute to the observed inhibiting actionItem Open Access Vaporization kinetics of Nigerian crude oil from different soil samples of Niger Delta(Medwell Journals, 2008) Uzoije, Atulegwu PatricThe vaporization/ volatilization kinetics of different Nigerian crude oil spilled on different soil samples has bee investigated. The rates of disappearance of these crude oil samples were low from soil sample of high clay, organic matter content and low porosity and versa. Crude oil samples with high molecular hydrocarbons contents also experience low disappearance rate.Item Open Access A comparative analysis of coconut, palm frond and palm stem fibres as erosion control materials on embankments(U. P., 2009) Egwuonwu, C. C.; Uzorije, A. P.The research focused on the use of fibres from coconut pud, palm stem and palm frond in erosion control on embankments. It compared single layer performance of the three fibres on three different slopes and a double layer performance of the coconut fibre. Two coconut fibre nets and a single net each for the palm stem and palm frond were used with a cell dimension of 2cm x 2cm and a boundary dimension of 360cm x 122cm. The fibres were in turn placed over a model of soil embankment in a soil bin. Rain was simulated for 30 minutes over the protected soil and the amount of soil loss deter mined. This soil loss was compared to the loss from the unprotected slope. The single and double layered coconut fibre were found to be more effective in reducing soil loss compared with the control experiment and fibres from palm frond and palm stem. For instance, for a slope of 3%, the soil loss from the single and double layered coconut fibres were 279.4g and 204.3, respectively, compared to 1051.6g, 322.80g and 310.60g for the unprotected soil, the palm stem fibre and palm frond fibre, respectively.Item Open Access Model for evaluating the concentration of Iion upgraded during pyrobeneficiation of Iron oxide ore pelletized with powdered potassium Chlorate(U. P., 2009) Nwoye, Chukwuka Ikechukwu; Obiji, Stephen; Anyika, Livinus; Nwoye, Uchenna Chukwuma; Obi, Marthins; Uzoije, Atulegwu Patrick; Ofoegbu, Stanley UdochukwuModel for predicting the concentration of iron upgraded during pyrobeneficiation of iron oxide ore (pelletized with powdered potassium chlorate) has been derived. The model-predicted %Fe upgrades were found to agree a direct relationship between %Fe values and weight-input of KClO3 as exhibited by %Fe upgrades obtained from the experiment. The model; %Fe = 7.1367γ indicates that iron upgrade is dependent on the weight input of KClO3. The validity of the model was rooted in the expression (%Fe/γ)α = (T/β)N where both sides of the expression are correspondingly almost equal. The positive or negative deviation of each of the model-predicted values of %Fe from those of the corresponding experimental values was found to be less than 19% which is quite within the range of acceptable deviation limit of experimental results.