Showing papers by "Rivers State University of Science and Technology published in 2007"
TL;DR: In this paper, an approach for the integration of RAMS and risk analysis can be developed as a guide in maintenance policies for the Afam thermal power station, in order to reduce the frequency of failures and maintenance costs.
86 citations
TL;DR: In this article, waste collected from different receptacles and dumpsites in Port Harcourt metropolis was subjected to analysis: on average, it consisted of 66.6% volatile solids, 13.5% fixed solids and 19.1% liquid and 0.8% other components.
76 citations
TL;DR: In this paper, the impact of rapid population growth due to uncontrolled and unplanned urbanization as it affects environmental degradation through solid waste generation in Port Harcourt Metropolis, which has brought about the problem of solid waste management to city authorities and state government was examined.
Abstract: Purpose – The purpose of this paper is to examine the impact of rapid population growth due to uncontrolled and unplanned urbanization as it affects environmental degradation through solid waste generation in Port Harcourt Metropolis, which has brought about the problem of solid waste management to city authorities and state governmentDesign/methodology/approach – The study involved the administration of questionnaires to 76 different households with a total population of 393 persons giving an average size of 7 persons per household. Also, formal interviews with officials of relevant government departments as wells as private stakeholders in urban solid waste management were conducted. The questionnaires were designed to elicit information on the characteristics of the respondents and waste generation capacity as well as disposal methods. The data abstracted from the questionnaires were analysed using the multiple linear regression to test for the significant differences. The study period was between Janu...
74 citations
TL;DR: In this article, bio-augmentation has been used as a bio-remediation option for hydrocarbon-contaminated, oily-sludge restoration in the Bonny-Terminal Improvement Project (BTIP) for Bonny Island, near Port Harcourt, Nigeria.
67 citations
TL;DR: In this paper, di-methyl ether and rape-seed methyl ester were used, both as neat fuels and for pilot injection, in a natural gas dual-fuelled compression-ignition engine, to examine the performance and the levels of exhaust emissions.
55 citations
TL;DR: In this paper, two trials were conducted to investigate changes in chemical composition and nutritive value of maize residues treated with urea and aqueous ammonia, and the results showed that the treatment improved the nutritional value.
55 citations
Journal Article•
TL;DR: In this paper, the physical and some frictional properties of African nutmeg (Monodora myristica), a wild perennial edible plant, were investigated at a moisture content level of 4.93% dry basis.
Abstract: Physical and some frictional properties of African nutmeg (Monodora myristica), a wild perennial edible plant, were investigated at a moisture content level of 4.93% dry basis. Measured values for sphericity, unit volume, average geometric diameter, unit mass, true density, bulk density, surface and pro- jected areas were 0.74 0.064, 1008 mm 3 169, 12.42 mm 0.70, 0.89 g 0.14, 830, 488 kg m -3 , 483 and 1216 mm 2 , respectively. The average values for coefficient of static friction on four test surfaces ranged from 0.502 (for galvanized iron sheet) to 0.702 (for rubber). Thus, the technical data obtained from this study may be useful in the design of process machines.
55 citations
TL;DR: In this article, the Navier-Stokes equation was used to model pulsatile blood flow in the cardiovascular system employing the PDE, and partial differential equations were solved approximately for the flow field.
43 citations
TL;DR: In this article, the authors investigated the tolerance level of maize on a crude oil contaminated soil using indices of plant performance such as plant height, leaf area and fresh cob yield, and found that maize can survive soil contamination of about 21% (similar to 177 000 mg/kg).
Abstract: This research sought to investigate the tolerance level of Zea mays (maize) on a crude oil contaminated soil using indices of plant performance such as plant height, leaf area and fresh cob yield. In the experiments described, conditions of a major spill were simulated by pouring different amounts of crude oil on experimental pots containing agricultural soil. Maize seeds were then grown amidst adequate fertilizer application and irrigation. The results of the study revealed that maize can survive soil contamination of about 21% (similar to 177 000 mg/kg) and still produce fresh cob yield of about 60% than on normal soil. There was a stimulated increase in fresh cob yield, than that obtained on normal soil at 12.5% soil contamination (similar to 112240 mg/kg). Hence, contaminant concentrations of 112 240 mg/kg and 177 000 mg/kg are identified as the ‘optimum yield limit’ and ‘lethal threshold’ respectively for maize growing on crude oil polluted soils. These results highlight the fact that, while concerted efforts should be made to remedy petroleum-contaminated agricultural soils, certain crops like maize can still produce beneficial yield in the presence of good soil management practices.
41 citations
TL;DR: In this paper, the results of laboratory investigations into the effect of drilled solids on the drilling rate and drilling performance were described in terms of electric stability (emulsion stability), high pressure high-temperature (HPHT) including the resultant filter cake, rheological properties of the active fluid.
37 citations
TL;DR: In this article, a 2-year study was conducted in the West African humid forest and southern Guinea savanna zones to determine fodder and tuber yields, fodder crude protein (CP) and neutral detergent fibre concentrations, and dry matter (DM) degradation characteristics of 18 sweet potato (Ipomoea batatas) cultivars harvested at 8, 12, 16, and 20 weeks after planting (WAP).
TL;DR: In Nigeria, a major problem is the corrosion of the external surfaces of such pipelines, which are not usually adequately safeguarded during construction as mentioned in this paper. And a cathodic protection system should be applied to the pipeline before this period.
TL;DR: Generally, the foods were microbiologically safe despite defective handling practices, and methods of food preparation and handling practices influenced the shelf lives of the foods, and their implications on microbiological quality and safety are discussed.
Abstract: The microbiological quality of selected ready-to-eat foods sold on the streets of Port Harcourt, Nigeria, was evaluated. Twenty to twenty-eight samples each of 10 different types of foods were analyzed. About 50% of the foods were deep fat fried, 20% were baked, 10% each were either boiled, pasteurized and frozen, or fermented and chilled products. Methods of food preparation and handling practices influenced the shelf lives of the foods, and their implications on microbiological quality and safety are discussed. The heterotrophic counts were highest for yogurt and ice cream and lowest for chin-chin and buns. Bacterial counts for pancake, moi moi, cake, meat pie and egg roll on McConkey agar gave comparable results with counts obtained on Deoxycholate agar. Eleven bacteria genera were isolated. Bacillus spp. and Klebsiella spp. occurred in most of the foods, followed by Staphylococcus spp. and Micrococcus spp., while other species exhibited a random distribution. Generally, the foods were microbiologically safe despite defective handling practices.
TL;DR: Thrombocytopenia is not only a feature of acute malaria infection but also that of asymptomatic malaria infection in the tropics and might be a useful indicator of malaria in children.
Abstract: Asymptomatic malaria infection is a common feature of malaria endemic regions in the tropics. In this prospective cross sectional survey, involving 240 children aged 1 to 8 years (Boys = 117, Girls = 123; Ratio 1:1.05), the median platelet count was 115 × 109/L (IQR 97.5–190). Thirty-three out of 240 (13.75%) of the children had thrombocytopenia (platelet count < 100 × 109/L). Malaria parasite was found to exert significant reduction in platelet count. This reduction was more pronounced in children under 5 years and also at higher parasite counts. An inverse relationship was established between parasite density and platelet count (y = −0.017x + 96.2, r = −0.2). Thrombocytopenia is not only a feature of acute malaria infection but also that of asymptomatic malaria infection in the tropics and might be a useful indicator of malaria in children.
TL;DR: In this paper, the authors evaluated the yield potentials of maize and cucumber intercrop resulting from the control of soil moisture through irrigation and mulching, for a period of eleven weeks.
Abstract: Replicate field plots were used in experiments aimed at evaluating the yield potentials of maize and cucumber intercrop resulting from the control of soil moisture through irrigation and mulching, for a period of eleven weeks Three irrigation depths, 25, 35 and 45 mm; and two mulch levels, zero mulch and 10 ton/ha of oil palm bunch refuse as mulch material were employed, while the third option involved the combination of the different levels of irrigation and mulching These were used alongside fertilizer application The pertinent growth and yield parameters were then determined Results of the analysis indicated that there were no significant differences in growth parameters such as plant height, vine length and days to 50% flowering across the treatment variants Yield components such as total grain yield, total fresh cob yield and total fruit yield differed greatly across the treatment options and also indicated significance at the 1% probability level It was observed that cucumber total fruit yield was greater in the plots that received only mulching than the other plots The results of the study highlight the position that the best crop yields would be obtained for maize and cucumber intercrop during the dry season, if farmers resort to optimum application levels while using the synergy of irrigation and mulching to achieve a crop favorable soil moisture regime
TL;DR: In this article, the relationship between daily aerosol index (TOMS AI) and horizontal visibility (Vx) during Harmattan seasons in the Sahel zone of Nigeria has been investigated using data from synoptic stations in the zone, and the strong correlation coefficient, r = - 0.92, indicates that TOMS AI captures the variability of atmospheric dust concentration in the region nearly as well as horizontal visibility from surface observation.
05 Aug 2007
TL;DR: In this article, a sample of the untreated LP-OBDC was collected from a mud pit close to an oil-well in the Niger Delta region of Nigeria, where the flocculation effluent was then subjected to an activated-carbon batch-adsorption process.
TL;DR: The parasites of P. falciparum obtained using the assumed value of 8.0 × 109/L was significantly higher than the parasite densities estimated using the individual WBC counts, which might result in over-estimation of the parasite burden.
Abstract: Aim: To compare malaria parasite densities, calculated using the white cell counts (WBC) of individual children with a standard WBC count of 8.0 × 109/L. Methods: In a cross-sectional study, the prevalence of malaria WBCs and malaria parasite densities were estimated in 240 healthy Nigerian children aged 1–8 years. Results: Of 240 children, 75 (31.25%) were infected with malaria, 69 (28.75%) with P. falciparum and 9 (3.75%) with other species. The mean (SD) WBC count was 5.1 (2.0) × 109/L. There was an age-related significant difference in the mean WBC counts (t=2.000, p<0.05), with values higher in the under-5s [5.6 (2.0) × 109/L] than in the ≥5-years group [5.0 (1.8) × 109/L]. No significant difference was observed with regard to gender and malaria infection. The mean (SD) parasite densities of P. falciparum obtained using the assumed value of 8.0 × 109/L [1936 (1119.5)] was significantly higher than the parasite densities estimated using the individual WBC counts [1140 (862.8) for P. falciparu...
TL;DR: There is a high prevalence of iron deficiency anaemia among apparently healthy children under the age of five years in this part of the world and these results may justify the need for the introduction of a broad intervention programme for this highly vulnerable group.
Abstract: The hemoglobin (Hb), serum iron (SI), total iron binding capacity (TIBC), transferrin saturation (TS) and serum ferritin (SF) values of 240 apparently healthy children were determined in a prospective cross-sectional study conducted in Port Harcourt, Nigeria. Standard colorimetric and enzyme immunoassay procedures were used for the estimation all variables. The mean values of all parameters in this study population were; Hb (11.2 +/- 1.83 gldl), TIBC (361.4 +/- 245.7 ugldl, log(c) SI (1.807 +/- 0.45), log(c) SF (1.51 +/- 0.47) and TS (29.3 +/- 18.5%). There was an age-dependent statistical significant difference in the Hb, TIBC and TS values (P < 0.01). Sex was not found to exert any significant influence on the parameters except TIBC. TS had the highest sensitivity and efficiency values of 48 and 95%, respectively. Positive predictive value (PPV), likelihood ratio (LR(+)) and post-test probability values were highest with SF (58%, 3.3 and 62.2%, respectively) as a diagnostic indicator. Hb values correlated positively and significantly with TS (P < 0.01), log(c) SI and log(c) SF concentrations (P < 0.05). Log(c) SF also correlated positively and significantly with Hb and TIBC (P < 0.05). The overall prevalence of iron deficiency anaemia among these children was 33.75%. We conclude that there is a high prevalence of iron deficiency anaemia among apparently healthy children under the age of five years in this part of the world and these results may justify the need for the introduction of a broad intervention programme for this highly vulnerable group. This study is also in support of the hypothesis that SF is the best test for diagnosing or excluding iron deficiency anaemia. The combination of SF, Hb and TS determinations may prove more useful in a resource-limited moderate setting.
TL;DR: The new Musa hybrids assessed are superior to the Agbagba plantain in nutritional value, which could enhance the adoption and utilization potential of these new hybrids by the local population.
Abstract: Introduction. A study was carried out to investigate the proximate and mineral com- position of plantain and banana fruits of new hybrids selected in Nigeria, compared with those of a local cultivar, Agbagba. Our aim was to assess their nutritional value and to enhance the adoption and utilization potential of these new selected hybrids. Materials and methods. Five new Musa hybrids developed at the IITA, Nigeria, were investigated. Proximate values of fat, carbohydrate and protein of the samples were determined and the energy content of each sample was calcula- ted. Fruit mineral analysis was performed for each cultivar studied. The data were statistically ana- lyzed. Results and discussion. All the new hybrids were higher than the local cultivar Agbagba in protein and crude fiber content. Conversely, Agbagba fruit had the highest level of carbohydrate. A significant difference was observed between the PITA 14 hybrid and the rest of the cultivars in total energy and fat content. Both the BITA 3 and PITA 26 hybrids contained the highest levels of ash. The PITA 17 hybrid contained the highest moisture. The PITA 14 and PITA 24 hybrids were diffe- rent from all other cultivars in phosphorus and copper contents. The calcium concentration in the PITA 14 and PITA 17 hybrids differed regarding the rest of the cultivars assessed. Also, the levels of potassium and manganese found in all the hybrids were different from those obtained in Agbagba, while the latter differed from all the hybrids in magnesium and sodium levels. Conclusion. The new Musa hybrids assessed are superior to the Agbagba plantain in nutritional value, which could enhance the adoption and utilization potential of these new hybrids by the local population.
TL;DR: Principal component analysis (PCA) ordinations discriminated all locations in the Obufe creek into a cluster along with the less-contaminated sites in the Azuabie creek, showing that they were contamination hot-spots.
Abstract: Two creeks (Azuabie and Obufe) in the upper Bonny Estuary, Nigeria were studied to determine how industrial and other anthropogenic activities have influenced their relative sediment qualities. Total organic carbon, total hydrocarbons, zinc, lead, cadmium and iron were significantly higher in the Azuabie creek, while phosphate, nitrate, copper and chromium did not show significant differences between the two creeks. Principal component analysis (PCA) ordinations discriminated all locations in the Obufe creek into a cluster along with the less-contaminated sites in the Azuabie creek. The other two sites in the Azuabie creek clustered separately, showing that they were contamination hot-spots.
TL;DR: In this paper, the authors used abrasion between a rotating shelling disc and stationary concave compartments to achieve the stripping of maize cobs, and achieved a shelling effectiveness of 67% with a low kernel breakage factor of 0.090 and a throughput of 6.82 kg/h.
Journal Article•
TL;DR: An experiment was carried out on red clay soils at the University of Zimbabwe Campus to determine the effects of nitrogen side dress on mustard rape growth and leaf taste and found increasing nitrogen fertilization increased yields and nitrogen levels in the leaves.
Abstract: Nitrogen management is crucial in cropping systems; it is often difficult to strike a balance between levels sufficient for normal plant growth and those that are acceptable for human consumption. An experiment was carried out on red clay soils at the University of Zimbabwe Campus to determine the effects of nitrogen side dress on mustard rape growth and leaf taste. The experiment was done over two growing periods, February to June and August to November 2004. Four nitrogen side dress levels; N 0, 34.5, 69 and 103.5 kg ha-1, were applied in mustard rape at three weeks after crop emergence (WACE) and two harvesting times; morning and sunset were included in the experiment. The eight treatment combinations were laid out as a 4 x 2 factorial experiment in a randomized complete block design with three replications. Leaves for the respective treatments were analyzed for nitrate and total nitrogen content using the sodium-salicylate and the improved Kjeldahl methods respectively. In both crop seasons, taste panels were conducted at five WACE using untrained panelists. Harvesting time only significantly affected nitrate and total nitrogen content of leaves but had no effect on all other parameters measured. Leaf nitrate content at five WACE was higher (0.537 mg kg-1) in samples harvested in the morning compared to the ones harvested in the evening (0.464 mg kg-1). Leaf size, plant height, fresh leaf yields, SPAD meter readings, percent nitrogen and nitrate content all significantly increased with increase in nitrogen fertilization. Leaf yields ranged from 5,000 kg ha-1 in the control to +16,000 kg ha-1 in the highest nitrogen fertilization rate (103.5 kg N ha-1) in the February planting. Leaf nitrogen content increased from the lowest value 3.66 mg kg-1 (control) to the highest value of 4.31 mg kg-1 (103.5 kg N ha-1). Leaf nitrate content also increased from 0.425 mg kg-1 in the control to 0.575 mg kg-1 in the 103.5 kg N ha-1 rate. SPAD meter readings increased from 24.48 in the control to 32.43 in the 103.5 kg N ha-1. Bitterness increased with increasing level of nitrogen fertilization with a significant correlation between nitrogen level and level of bitterness of R = 0.503 (p<0.01). Increasing nitrogen fertilization increased yields and nitrogen levels in the leaves. Evening leaf harvest had less nitrate levels in the leaves. Taste panelists also indicated the improvement of the appearance of leaves after preparation with increasing nitrogen side dressing giving a significant negative correlation between the two (p < 0.01, R = -0.259).
TL;DR: The use of simulation analyses demonstrated that the various species that were similar in terms of habitat use partitioned their microhabitat niche, reducing potential interspecific competition.
Abstract: We examined the guild structure of geckos at a farmbush–rainforest mosaic area in southern Nigeria, during three independent survey periods (i.e. dry season of 1997, 2001, and 2005). We used several simulation descriptors (C value, V ratio, number of checkerboard species pairs, number of species combinations), generated by Monte Carlo methods, to contrast the actual data matrix with the randomly generated data matrix. We calculated the relative availability and use by species of habitat types and microhabitat types at each of these survey periods and also studied temporal niche aspects. We found that our gecko guild was composed of six species, including native forest specialists as well as native habitat generalists and exotic species linked to human-made habitats. Monte Carlo simulations revealed the occurrence of a structure in the guild under study with regard to habitat type but not with regard to (a) two types of microhabitat uses (i.e. perch height and size of trees) and (b) daily time. The use of simulation analyses also demonstrated that the various species that were similar in terms of habitat use partitioned their microhabitat niche, reducing potential interspecific competition. On the other hand, those species that were clearly separated with regard to habitat type readily frequented the same microhabitats within different habitat types.
Journal Article•
TL;DR: The presence of under nutrition places children (especially below 5 years of age) at higher risk of malaria related morbidity and children in malaria endemic areas need adequate nutrition to withstand the negative impact of malaria.
Abstract: Our study in Port Harcourt children with asymptomatic malaria aimed at assessing the baseline anthropometric indices of nutritional status and whether their nutritional status (especially under nutrition) offers any advantage for living in malaria endemic areas. Cross-sectional study was used. The setting used was Rumueme Community in Port Harcourt Nigeria. The subjects for the study were apparently healthy children aged 1 - 8 years of both sexes (Boys = 117 Girls = 123; Ratio 1: 1.05) 240 children from randomly selected households within the study community participated in the study. Of the 240 children 66 (27.5%) were infected with malaria (P falciparum). Children below 5 years had a higher parasitaemic rate (36.36%) than those in 5-8 years group (21.27%). Our baseline data showed that 17.5% were underweight (WFA Z less than -2) 3.75% were stunted (HFA Z less than -2) and 22.5% were wasting (WFH Z less than - 2). Children who are underweight were found to be at higher risk of acquiring malaria infection than the well nourished children (RR = 1.02 x/2 = 0.320 p less than 0.02 95% CI 0.34-2.37). Under nutrition was more prominent in the children below 5 years than the older children (RR = 3.625 x/2 = 10.36 p less than 0.006 95% CI I.81-5.43). The haemoglobin value of parasitized children (10.8 plus or minus 1.9 g/dl) was significantly lower than the non-parasitized group (11.3 plus or minus 1.7 g/dl) (p less than 0.01). We concluded that the presence of under nutrition places children (especially below 5 years of age) at higher risk of malaria related morbidity. Children in malaria endemic areas need adequate nutrition to withstand the negative impact of malaria. (authors)
Posted Content•
TL;DR: In this paper, four regression models using the available data of Nigerian quoted small and medium-sized enterprises (SMEs) between 1999-2003 were used to test the relationship between current ratio and gross profit margin, holding the working capital gap constant.
Abstract: This article tests four regression models using the available data of Nigerian quoted small and medium-sized enterprises (SMEs) between 1999-2003. It is conceptualised that sustained growth, adequate liquidity and requisite profitability in the SME sector is significantly related to their investment and financing decisions. The empirical results show a significantly inverse relationship between current ratio and the gross profit margin, holding the working capital gap constant. This portrays a 'financial management dilemma' as the Chief Finance Officer (CFO) endeavours to synchronise the conflicting objectives of liquidity and profitability. It is also shown that neither the total assets turnover nor the fixed assets turnover ratios is significant in determining the gross profit margin in Nigerian quoted SMEs. Moreover, a 1 per cent increase in the current ratio brings about a more than proportionate decrease in the debt-equity ratio and the debt-assets ratio. The quoted SMEs' current asset ratios are significantly sensitive to commercial banks' liquidity ratio, cash reserve requirements, and the loan-to-deposit ratio. Overall, our model results confirm that the SME sector in Nigeria is still limited by the liquidity-profitability dilemma, efficiency constraints, pecking order reversals, stringent monetary policy regimes and a risk-averse banking system.
TL;DR: In this paper, the effect of bioremediation on the performance of Okro plant (Abelmoshus esculentus) in a typical Niger Delta soil that has received 5% crude oil pollution level was communicated.
TL;DR: The results suggest that BLCO caused the increased availability of crude oil hydrocarbons in the liver cells, and subsequent induction of unscheduled mt.DNA synthesis, and alteration of mitochondrial/endoplasmic reticulum Ca2+ sequestration or ca2+ - concentration gradient, leading to the inhibition of Ca2- influx into the cytosol.
Abstract: The alteration of cellular calcium sequestration has been postulated to be a primary mechanism in the initiation of irreversible cell damage. Crude oil has been shown to cause concentration- dependent inhibition of calcium influx and mitochondrial swelling which may relate to its toxicity. Nigerian ‘Bonny’ Light Crude Oil (BLCO) is produced in the Niger-Delta region of Nigeria where oil spills are frequent and can endanger human-health, yet BLCO has not been studied in this regard. We have studied the effects of two doses of BLCO on mitochondrial DNA (mt.DNA), cytoplasmic total hydrocarbon concentrations (cyt.THC) and cytoplasmic Ca2+ (cyt.Ca2+) concentrations in livers of adult male guinea pigs exposed by intraperitoneal injection. The results showed that at 2.5 and 5.0 (ml/kg bw), BLCO caused dose-related increases in mt.DNA concentrations (128% and 485%) respectively over the controls, and cyt.THC (47.5% and 100%) respectively; while it caused near-100% decrease in cyt.Ca2+ concentrations (94% and 96.8%) respectively lower than the controls. These results suggest that BLCO caused the increased availability of crude oil hydrocarbons in the liver cells, and subsequent induction of unscheduled mt.DNA synthesis, and alteration of mitochondrial/endoplasmic reticulum Ca2+ sequestration or ca2+ - concentration gradient, leading to the inhibition of Ca2+ influx into the cytosol. These events may explain the probable hepatotoxicity of BLCO.
TL;DR: In this paper, the interface between official corruption and money laundering in Nigeria and suggest ways of curbing these crimes is examined and the relevant laws dealing with these offences were examined to assess the adequacy or otherwise of the statutory provisions.
Abstract: Purpose – This paper aims to examine the interface between official corruption and money laundering in Nigeria and suggest ways of curbing these crimes.Design/methodology/approach – The relevant laws dealing with these offences were examined to assess the adequacy or otherwise of the statutory provisions. The key provisions of the Criminal and Penal Codes were discussed in addition to the new enactments dealing with these crimes, namely, the Independent Corrupt Practices and Other Related Offences Act, the Economic and Financial Crimes Commission Act, the Money Laundering Act as well as the Code of Conduct Bureau and Tribunal provided for in the 1999 Constitution.Findings – It was found that these recent enactments have gone much further than the earlier provisions dealing with these crimes. They contain some far‐reaching innovations such as the provision for the appointment of an Independent Counsel to investigate allegations of corruption against the president, vice president, governors and deputy gover...