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Open Access
Molecular identification and safety assessment of microorganisms in okpeye sold in Owerri and Onitsha markets in South-eastern Nigeria
(Federal University of Technology, Owerri, 2004-10) Agunwah, Ijeoma Maureen
Okpeye an indigenous fermented condiment produced from Prosopis africana seeds was assessed to evaluate the microbilogical quality of the condiment. Eighteen (18) commercial samples of okpeye were purchased from six markets in two cities in South Eastern Nigeria. Fifty-nine (59) bacteria colonies were isolated and identified at the species level by phenotyping and sequencing of the 16S rRNA, gyrB and rpoB genes. Bacillus (47.4%) and Staphylococcus (42.3%) were the predominant bacterial species in okpeye. Overall, B. amyloliquefaciens and S. simulans were the most frequently occurring bacteria and were present in all samples. In addition, B. cereus was isolated in samples obtained from all markets. Other bacterial species included B. velezensis, Oceanobacillus caeni, S. cohnii, Escherichia fergusonni and Vagacoccus lutrae. The B. cereus isolates (10) were screened for the presence of 8 enterotoxin genes (hblA, hblC, hblD, nheA, nheB, nheC, cytK, entFM) and one emetic gene (cesB). The non-haemolytic enterotoxin (nhe ABC) and haemolytic enterotoxin (hbl ABD) complexes were present in 70% and 50% of B. cereus respectively. The positive rate of cytK and entFM genes was 70%, while the cesB gene was 30%. The haemolysis test revealed twenty- three isolates out of the twenty-eight isolates tested showing full haemolytic activity on blood agar. Two isolates (O22 and A22) showed partial haemolysis while three (O11, O15 and A12) showed no haemolysis.Antibiotic susceptibility assessment showed that most of the isolates were susceptible to gentamicin, tetracycline, streptomycin, and erythromycin but resistant to ciprofloxacin and vancomycin. These findings highlight the need for further controls to reduce contamination with potential pathogenic bacteria in indigenous fermented condiments such as okpeye. Two isolates that gave the best safety assessment results were used as starter cultures for the fermentation of Prosopis africana seeds. The bacterial load of seeds fermented with the starter cultures was slightly higher than the spontaneously fermented seeds with a value range of (7.7- 9.4 log10 Cfu/g). The seeds fermented with mixed cultures of B. licheniformis and B. amyloliquefaciens had the highest pH (9.14), temperature (39.96oC) and titratable acidity (TTA) (1.03%) after 168 hours of fermentation. The protein, fat, ash and carbohydrate content were higher in okpeye fermented with starter cultures (B, C and D) than that of the commercial samples (E). The spontaneously fermented sample (A) had the highest protein content (27.80%) than all the other samples. The phytochemical composition showed that okpeye fermented with mixed cultures of B. licheniformis and B. amyloliquefaciens had the highest oxalates (11.52%), saponins (0.05%), phytates (549.75 mg/100g), alkaloids (13.03%) and flavonoids (14.20%) than the commercial and spontaneously fermented samples. The spontaneously fermented samples had the highest tannin (13.29 mg/100g) and total phenol (330.36 mg/g) than all the other samples. The commercial sample had the least phytochemical nutrients except for phytate (58.53 mg/100g) and cyanide (1.60 mg/g). The sensory analysis showed that soup cooked with okpeye fermented with mixed cultures of B. licheniformis and B. amyloliquefaciens had the best results in aroma (7.27), flavour(7.40), appearance (7.30), after taste (7.17) and overall acceptability (7.31). The sensory results showed that okpeye fermented with mixed cultures of B. licheniformis and B. amyloliquefaciens was well accepted by consumers. Based on this acceptability as well as the nutritional composition and phytochemical composition, mixed cultures of B. licheniformis and B. amyloliquefaciens c be recommended in the fermentation of P. africana seeds to produce safe and good quality okpeye.
Open Access
Sequestration and dynamic of carbon and nitrogen in soils of dissimilar lithologies under different land use types in Southeastern Nigeria
(Federal University of Technology, Owerri, 2015-06) Ahukaemere, Chioma Mildred.
The study was conducted to determine carbon and nitrogen sequestration and dynamics in soils developed on different parent materials (Coastal Plain Sand, Falsebedded Sandstones and Shale) under different land use types (forest, fallow and cultivated lands) in South-eastern Nigeria. Geology maps were used to guide the location of sampling sites. Three parent materials and three different land use types in each of the parent materials were randomly selected. The study was a three factor experiment laid in a randomized complete block design (RCBD). A total of 27 profile pits were studied. Soil samples were collected from each of the profiles according to their horizons. Undisturbed soil samples for determination of bulk density were collected in core samplers. Small portions of the samples were air dried, crushed and sieved using a 2-mm sieve in preparation for laboratory analyses. Carbon and Nitrogen forms and sequestration, morphological and physico-chemical properties of soils were determined. Data were subjected to ANOVA , multiple regression, coefficient of variation and correlation analyses. From the results, carbon sequestration ranged from 3229 gCm2in Falsebedded sandstone-derived soils to 3648 gCm2 in Shale-derived soils, and did not differ significantly across the soils. Nitrogen sequestration differed significantly (p < 0.001) with soils derived from Coastal plain sands having higher quantity (248.00 gNm-2) while the least was recorded in soils formed from Shale (91 gNm2). The C sequestration capacity of the soils of the different land use types varied significantly (p < 0.05) with fallow soils derived from Falsebedded Sandstone and Coastal plain sand containing the highest quantities (4753 gCm-2 , 4222 gCm-2). Carbon and nitrogen sequestration increased with horizon thickness in all the profiles across the soils studied. The mean total carbon contents ranged from 39.20 to 82.80 gkg-1across the soils and did not follow uniform pattern of distribution down the profiles, except in fallow soils of the Falsebedded Sandstone where it increased with depth. Soils derived from Shale had the least quantity of total carbon while those of Falsebedded Sandstone had the highest value. Forest soils had higher quantity of total carbon (109.20, 42.40 gkg-1) compared to those of fallow and cultivated soils of the Falsebedded sandstone and Shale . Organic carbon constituted about 58% of total carbon in Shale-derived soils, 20.81% in Coastal plain sand and 27.66 % in Falsebedded sandstone –derived soils. In soils of the different land use types, forest soils contained significantly higher proportion of organic carbon, followed by fallow and lastly by those of the cultivated lands. Organic carbon correlated significantly with clay (r = 0.513, 0.578) (p < 0.001), WSA (r = 0.506, 0.626, 0.646) (p < 0.001) and BD (r = - 0.537, - 0.900, -0.736 ) (p < 0.001) respectively. The mean total nitrogen contents of the soils varied from 5.49 - 8.24 mg/kg in soils of dissimilar parent materials, 3.60 - 14.33 mgkg-1, 7.33 – 8.87 mgkg-1, 2.01 – 10.49 mg/kg in soils of the different land use types. Soils formed from Coastal plain sand and Falsebedded sandstone contained significantly higher (p < 0.01) quantity of total nitrogen than those of Shale. In soils of the different land use types, forest soils contained significantly higher (p < 0.001) proportion of total nitrogen (14.33, 10.49 mgkg-1) than fallow and cultivated soils. Soils formed from Falsebedded sandstone and Shale had significantly higher (p < 0.001) proportions of available N compared to those of Coastal plain sand. In soils of the different land use types, forest soils had significantly higher proportion of available N compared to fallow and cultivated soils. Soils developed on different parent materials under different land use types had varying colour matrix ranges. Soil texture ranged from sand, loamy sand to sandy loam in soils derived from Coastal plain sand and Falsebedded Sandstone, loam, sandy clay loam, silt clay loam to clay in Shalexiiderived soils with soils formed from Shale containing significantly (p < 0.001) higher proportion of clay (263 gkg-1) than those of Falsebedded sandstone (77 gkg-1) and Coastal plain sand (90 gkg-1). The mean bulk density (BD) values ranged from 1.06 to 1.22 gcm-3in soils derived from the three parent materials. Forest soils had the least bulk density values (0.98, 1.09, 1.08 gcm-3) compared to other land uses. In soils of different parent materials, Shale derived soils had highest percentage moisture content (12.49%) while those derived from Falsebedded sandstone had the least amount (9.09%). In soils under the three land use types, forest and fallow soils had significantly higher (p < 0.001) quantity of soil moisture than the cultivated soils. Shale-derived soils had significantly higher (p < 0.001) stable aggregates (29.23%, 1.35 mm) than those derived from Coastal plain sand and Falsebedded sandstone. In soils of the varying land uses, soils of the forest had significantly higher (p < 0.001) stable aggregates compared to those of fallow and cultivated lands. Soils were slightly acidic across the parent materials and land use types. Significantly (p < 0.01) least proportion of Calcium (Ca) (2.76 cmolkg-1) was recorded in soils of the Falsebedded sandstones while those developed on Shale had the highest quantity (4.28 cmolkg-1). Significantly higher percentage base saturation was obtained in soils derived from Shale (91.4%) while the least value was obtained in Falsebedded sandstone-derived soils (68.71%). Taxonomic classification was done to the Subgroup level. The soil classes derived from soil taxonomic classification of the USDA was correlated with the World Reference Base. Soils were classified as Grossarenic Kandiudults (USDA), Chromic Acrisols (WRB), Typic Kandiudults (USDA), Rhodic Acrisols (WRB), Lithic Kanhapludults (USDA), Rhodic Acrisols (WRB), Arenic Kandiudults (USDA), Chromic Acrisols (WRB), Vertic Paleudults (USDA), Haplic Acrisols (WRB), Entic Paleudults (USDA), Haplic Acrisols (WRB), Psammentic Hapludults (USDA), Arenic Acrisols (WRB)
Open Access
Application of deterministic and stoichastic analysis of fault seal integrity in Baka Field, Niger Delta
(Federal University of Technology, Owerri, 2015-12) Njoku, Ikechukwu Onyema
Fault seal analysis in fault dependent reservoirs were carried out at different reservoir levels in the Baka Field, Niger Delta. These involved stratigraphic correlation, 3-D seismic interpretation of faults and horizons, time-depth conversion of all interpreted faults and structural maps using both check-shot and synthetic seismogram. Also, static models of all interpreted reservoir levels, and 3-D deterministic and stochastic fault seal integrity models were carried out. The deterministic approach applied in this study is sensitive to uncertainties associated with mapping of horizons in the proximity of faults and the inherent uncertainties in the static fault interpretation in both position and fault zone properties complexity. However, the integration of stochastic approach captured the uncertainties in the position of the reservoirs at all interpreted faults by allowing multiple realizations of stacking geometries relative to their lateral reservoir distribution. All hydrocarbon bearing reservoir levels and faults were interpreted in detail on seismic and a structural framework model was built for juxtaposition analysis and fault shale gouge ratio calculation. The interpreted hydrocarbon columns of the reservoirs in the field are mostly controlled by structural spill points, implying that the faults affecting the accumulation must be effectively sealed which is evident from calculated high SGR values. Some reservoirs are under filled, indicating that the faults are leaking. It was shown that these fault intervals have relatively low SGR. There is high degree of conformity between field hydrocarbon column heights and the stochastic column heights predicted from the shale gouge ratio. The calculated shale gouge ratio quite matched with the shale gouge ratio related column height distribution used in exploration. Top shale thickness played a role (impede up dip fluid conduit), but not a major factor in the Baka reservoirs as regards to column controls. Also, faults in the Baka Field leaks at <20% shale gouge ratio with varying weak points, mainly 20 – 35% shale gouge ratio and more. Good fault seal capacity exists in the Baka Field at >40% shale gouge ratio. Shale gouge ratios are higher at the boundary fault.
Open Access
Proximity of waste dump sites to residential neighbourhoods and the incidence for malaria among under five children in Port Harcourt, Rivers State
(Federal University of Technology, Owerri, 2015-12) Amachree, Mikiai Tuboibibo Kieni
Epidemiological studies suggest that there may be an association between environmental exposure to waste dumpsites and malaria. The aim of this study was to investigate whether residential proximity to waste dumpsites result in increased rate of morbidity for malaria among the most vulnerable population groups such as children under the age of five. A total of 150 children between the ages of one and five years were sampled in a residential neighbourhood in Eneka, Port Harcourt. Data were obtained from the parents of the subjects with the aid of a specially- designed and well-structured questionnaire, review of hospital records, assessment of exposure and assessment oflarval abundance. Results showed that among the subjects within the total sample of 150 subjects, there were 1670 reported cases of malaria among the subjects within 11months study period. Of this total, 1272 (76.1%) cases were treated in zone A (distance below 500 meters) and 398 (23.8%) in zone B (distance more than 500 meters). The Spearman correlation coefficient calculated between rate of morbidity and distance from dumpsite in zone A was r = 1.12 (p < 0.05) and was adjusted for other factors that may have contributed to the disease. The overall results showed that children living within a distance below 500 meters from the dumpsite (zone A) are 3.5 times more likely to suffer malaria than those living beyond 500meters‟ distance (zone B). A trend of lower incidence of malaria was therefore noted among children living in zone B. These results show that municipal waste dumpsites create pathological zones in which disease vectors proliferate and pose significant dangers within the residential neighbourhood
Open Access
Studies on dietary fermented mixture of cassava and palm kernel cake on carcass characteristics of broilers and pigs
(Federal University of Technology, Owerri, 2016-03) Aladi, Nnanyere Okwunna
Five experiments were carried out to determine the effect of replacing maize with solid state fermented mixture of cassava root pulp and palm kernel cake on performance, carcass and meat quality of broiler chicks and pigs. First, 3 inoculation techniques were evaluated for their efficacy in solid state fermentation of the mixture namely; direct inoculation with Aspergillus niger, batch inoculation with previously inoculated samples, and spontaneous inoculation. In study 2, sundried spontaneously fermented samples (FEMCARPP) were used to replace maize in broiler chicks diets, whereas in study 3, the performance, carcass characteristics and meat quality of broiler finishers fed diets containing wet or sundried FEMCARPP were compared to the controls (maize based diet) and another diet containing a mixture of cassava root meal and palm kernel cake (CSM-PKC mix) as replacement for maize. In study 4, FEMCARPP was used to replace maize in diet of weaner pig whereas study 5 evaluated the performance, carcass and meat quality of pigs fed diets in which maize was replaced FEMCARPP and CSMPKC mix. Results show that, all inoculation techniques were efficient in improving the physicochemical characteristics of the mixture for inclusion in poultry ration. Dustiness of cassava meals was completely removed, protein content increased significantly, while crude fibre levels reduced in treatments relative to the control. Broiler chicks fed sundried FERMCARPP had significantly (p<0.05) lower live weight gains, feed intake, feed conversion ratio and cost per kg weight gain than those fed the control diet. Carcass characteristics were similar (p>0.05) while meat quality of chicks fed diets containing FEMCARPP was better (p<0.05) than the control and CSM-PKC mix diets. Chicks fed wet FEMCARPP had lower live weight gains and feed intake (p<0.05). Their feed conversion ratio was similar (p>0.05) to the control but superior to chicks fed diets containing sundried FEMCARPP and CSM-PKC mix. Cost per kg weight gained was better among chicks fed FEMCARPP without sun drying. Pigs at both weaner (study 4) and grower-finisher (study 5) stages fed diets on FEMCARPP was high (p<0.05) in live weight, weight gain, lower feed intake, feed conversion ratio and lower cost per kg weight gained. No significant differences were found for carcass characteristics of pigs. Meat of pigs fed maize based diets was significantly (p<0.05) higher water holding capacity and cooking loss; but with lower tenderness score when compared to those fed FEMCARPP based diets. Both were tenderer than those fed CSM-PKC diet. It is therefore concluded that solid state fermentation of spontaneously inoculated mixture of cassava root pulp and palm kernel cake is an effective tool for improving the nutritive value of the mixture for use in poultry and pig diets. The product can be used without further drying to replace maize in poultry and swine diets without detrimental effects on production, health, and carcass and meat quality of broilers and pigs. Solid state fermentation of spontaneously inoculated mixture of cassava root pulp and palm kernel cake is therefore recommended for poultry and pig farmers for efficient productivities and profit.
Open Access
Physico-mechanical properties of natural rubber filled with treated groundnut shell powder for shoe sole production
(Federal University of Technology, Owerri, 2016-03) Ayo, Mark Dada
Physico-Mechanical properties of natural rubber filled with chemically modified groundnut shells were studied. Natural rubber composites were prepared using modified fillers at varying concentrations of sodium hydroxide (NaOH) Solution and acetylating solutions respectively. The processing conditions, mechanical properties and sorption characteristics of these composites were analyzed. The cure characteristics of the compounded rubber were determined using Mosanto Rheometer (model MDR - 2000). The maximum torque and crosslinking density increases with increase in concentration of the mercerizing and acetylating agent. The fibre reinforcing efficiency of the chemically treated composites were compared with that of the untreated composite. Composites containing chemically treated fillers were found to posses improved tensile properties(from 18.30 to 31.50MPa for acetylated composites and 18.30 -28.00MPa for mercerized fillers), hardness (48 to 65 IRHD for acetylated filler and 48 to 58 for mercerized fillers) and abrasion resistance (from 31.55 t0 42.50% for acetylated filler and 31.5 to 39.30 for mercerized filler). These properties increases with increase in mercerizing and acetylating agent up to 20% concentration and starts decreasing. At higher concentration, the fibre is destroyed hence reduction in properties. These results were in agreement with empirical analysis. The sorption properties of the composite also decrease with the concentration of the mercerizing and acetylating agent. The improved properties observed were as a result of the increase in affinity between the rubber matrix and the chemically treated groundnut shell fillers. From this research work, it is recommended that chemically treated groundnut shell powder, particularly at 20% concentration can be employed for articles such as shoe soles, footmats and hoses that require less stress during service life.
Open Access
Studies on characteristics of pastoral cattle production in Adamawa State, Guinea Savannah Zone of Nigeria
(Federal University of Technology, Owerri, 2016-04) Ibrahim, Hayatu Kubkomawa
The main objective of the study is to characterize aspects of pastoral cattle production in Adamawa state, guinea savannah zone of Nigeria in order to understand the socio-cultural conditions of key stake holders, the common cattle breeds, available feed resources and morpho-physiological conditions of cattle grazing in the zone. The study was divided into two phases to elucidate production characteristics at the pastoralists and semi sedentary levels of production in three Local Government Areas (LGAs) of the state namely, Mubi north, Gombi and Jada. Pastoralists‘ production component of the study was carried out with the aid of questionnaire, oral interview and field observations on 300 respondents spread across the three study LGAs, while the semi-sedentary component was carried out on one purposively identified cattle farm in each of three LGAs. Morpho-physiological parameters studied included body condition score (BCS), rectal temperature (RT), respiratory rate (RR), pulse rate (PT), hematological and serum biochemistry were determined. Most preferred dry season feed resources and water consumed by the animals were analyzed for the nutrient compositions and quality respectively. Data generated were subjected to descriptive statistics and interactions of different study parameters were also determined. Pastoral cattle production in Adamawa state was predominated by highly experienced (80 – 85%), married (75 - 88%), Fulani (95 – 65%) male (75 – 90%), Muslims (75 – 80%) aged mostly 31 – 40 years (48 – 55%) and having limited western education. White Fulani breed (50.00%) are most common in Gombi LGA, while Red Bororo (53.00%) and Adamawa Gudali (50.00%) were most predominant in Mubi North and Jada LGAs respectively. Most of the pastoralist (40 – 50%) maintained herd size of 41 to 50 heads and reared cattle for multiple purposes such as breeding, milk, meat and traction. Farmers practiced uncontrolled breeding, with bull to cow ratio of 1:10 (75.00% at Mubi north LGA). First mating (50 – 60%) was done between 4 and 5 years, while age at first calving was mostly (73 -75%) was mostly 5 – 7 years indicating serious reproductive life wastage. Most pastoralists (55 – 65%) use ethno-veterinary practices to enhance cattle reproductive performance. Calving rates (75 – 85%) were more during late rainy season (LRS), while (90.00%) depended on natural pastures for feeding their cattle. Cattle grazed 21 grasses and 19 legumes during the wet periods, while 12 crop residues, 7 by-products and 10 browse plants were offered during dry periods as supplements. Most of the pastoralists (70.00 - 90.00%) depended solely on natural flowing streams and rivers for the supply of water to their cattle. The major production constraints (43.33%) identified was diminishing natural resources characterized by shrinking land and vegetal resources. xviii Methods for reducing poor morphometric effects of lean feed resources were forage conservation as hay, supplementation with tree fodder, migration and splitting of herds. BCS was significantly (p<0.05) better in Adamawa Gudali, semi-sedentary production and during LRS, while RT, RR and PR were significantly (p < 0.05) different across LGAs. RBC counts were normal but male values were significantly (p < 0.005) higher than the female values. Similarly, PCV, Hb and WBC were within normal range for cattle although significant (p<0.05) differences were observed across LGAs. Male AST, ALT and ALP values were also significantly different from female values although within normal range. Interactions of breed or management effects with morpho-physiological parameters were also significant (p<0.05) for PR, RBC count, PCV, MCV, MCH, MCHC, AST and ALT, with these interactions being more significant in Adamawa Gudali and Red Bororo in most cases. Pasture resources were more abundant during the LRS and EDS, while crop residues/browse resources predominated during the other seasons. It was concluded that Adamawa Gudali out-performed the other breeds on many parameters followed by Red Bororo, reflecting their earlier adaptation to the study area. The semi-sedentary production system generated better performance results than the pastoral system. The major constraints to pastoral cattle production in the study area were seasonal feed and water shortages, shrinking pasture lands, desertification linked to changes in the production environment, with resultant insecurity and poor animal performance. Appropriate government agencies should formulate policies to address the static socio-cultural conditions of pastoralists in Nigeria that resists adoption of agricultural technologies adapted to the realities of a modern world.
Open Access
Isolation, characterization and radical-scavenging potentials of bioactive components of combretum dolichopentalum leaves
(Federal University of Technology, Owerri, 2016-04) Ujowundu, Favour Ntite
The present study isolated, identified and characterized the bioactive components of Combretum dolichopentalum leaves and determined the antioxidant potentials of the extracts of the leaves on some biochemical and physiological parameters. Biochemical methods such as ion exchange chromatography, column chromatography, thin layer chromatography, gas chromatography (GC), gas chromatography-mass spectrometry (GC-MS), spectrophotometric analyses, atomic absorption spectrometry and Fourier transform infra red (IR) were used. Preliminary phytochemical analyses showed the presence of flavonoids, alkaloids, saponins, tannins, oxalate and phytate. Further screening show the presence of flavonoids: kaempferol, luteolin, isorhamnetin and apigenin; alkaloids: akuamidine, undulantine, powelline and their hydroxylated compounds, voacangine and buphranidine; saponins: hicogenin, sapogenin, tribuloin and tannic acids. The use of GC-MS aided the identification of organic acids: (heptedecanoic acid), organic esters (ethyl octadecanoate), ketones (6,10-dimethyl-2- undecanone), alcohols (3,7,11,15-tetramethyl-2-hexadecen-1-ol) and phenol derivatives (Phenol-2,6-bis (1,1-dimethyl)-4 -methyl, methyl carbamate). Also, the eluates obtained from column and thin layer chromatography were analysed with IR and phenol-2,6-bis (1,1- dimethyl)-4-methyl, methyl carbamate, nitrocyclohexane, fluorodecane and others were identified. Proximate analysis showed the presence of carbohydrates, proteins, lipids, sodium, potassium, phosphorus, vitamins A, E and B-vitamins. Amino acid profile using the technicon sequential multi-sample amino acid analyser (TSM) showed the presence of essential and non essential amino acids. The effects of isolates such as flavonoids, saponins, alkaloids and tannins were determined for in vitro hydrogen peroxide scavenging ability. The effects of the extract in comparison with a standard drug (silymarin) on animal organ/tissue functions and on serum concentrations of electrolytes, beneficial transition minerals, lipids, antioxidants and markers of lipid peroxidation were determined. The effects of the crude extract in comparison with standard plant antioxidant (quercetin) and butylated hydroxyl toluene (BHT), for in vitro scavenging potentials showed dose dependent scavenging potentials on nitric oxide, hydroxyl radical, H2O2 induced lipid peroxidation and reducing power. Intoxication with CCl4 after pre-treatment with the ethanol extract and crude flavonoid, saponin, alkaloid and tannin fractions indicated hepatoprotective and antinephrotoxic potentials except saponins isolate which showed a significant (P˂0.05) adverse effect as indicated by some biochemical and physiological parameters. Flavonoid and alkaloid extracts are the major fractions that elicited biochemical and physiological benefits in CCl4 intoxication. The in vitro and in vivo radical scavenging properties of extracts of C. dolichopentalum make a promising drug with strong antioxidant potentials and inhibitory against Escherichia coli and Salmonella typhi.The present study isolated and characterized the phytochemicals in C. dolichopentalum leaves which could be further exploited for the treatment of oxidative stress and microbial induced disorders and diseases especially in light
Open Access
Use of modified sweet potato starches as corrosion inhibitors of selected metals
(Federal University of Technology, Owerri, 2016-07) Anyiam, Chioma Kezaiah
Sweet potato starch was modified via extrusion, alkaline steeping and acid steeping to yield physically modified starch (PMS), alkaline treated sweet potato starch (ASS) and acid treated sweet potato starch (ATS). The unmodified and modified starches were characterized using the Fourier transform infrared spectroscopy and assessed for corrosion inhibition efficacy on mild steel and galvanised steel in 0.25 M H2SO4 and 1 M HCl using gravimetric (weight loss) measurements and potentiodynamic polarization techniques. All the starch samples inhibited corrosion of the metals in the acidic media, with maximum efficiency ranging from 22.86 to 62.76 % for mild steel and 24.27 to 63.48 % for galvanised steel. Introduction of potassium iodide notably increased inhibition efficiency up to 85.59 %, 85.09 %, 83.64 %, 87.72 % for NS, PMS, ASS, and ATS respectively for mild steel and for galvanised steel 92.60 %, 95.62 %, 93.67 % and 93.94 % respectively for NS, PMS, ASS and ATS. Fourier transform infrared spectroscopy was used to analyse the scrapped metal after corrosion in presence and absence of the additives in the acidic media. Atomic force microscopy was used to analyse the surface morphology of the corroded metals in the presence and absence of the additives in the acidic media. The inhibitor adsorption characteristics were found to obey Langmuir isotherms. Temperature studies (30-60OC) investigated showed higher inhibition efficacy at lowest temperatures, thus suggesting physiosorption adsorption mechanism. These results were in agreement with the kinetic and activation energy parameters investigated. Potentiodynamic polarization measurements showed that NS, PMS, ASS and ATS are mixed-type inhibitors.
Open Access
Effects of starch blends and processing technique on some properties of biodegradable polymer drilling muds
(Federal University of Technology, Owerri, 2016-07) Chike-Onyegbula, Catherine Oluchi
This research was carried out on “Effects of Starch blends and Processing Technique on some Properties of Biodegradable Polymer Drilling Muds”. Several biodegradable polymer drilling muds were prepared using starches from local corns and millet pregelatinized and blended by extrusion technique in the absence of any solvents or chemicals. The filtration and rheological properties of the new muds and three already existing muds were studied at 25oC-450oC temperature range and at 0.01-0.05g/ml concentration of each starch using filter loss method and viscometric method respectively. The biodegradation properties of the muds were studied with their respective starches using soil burial test method and plant growth method. The experimental results were also modelled using MATLAB software method of modelling. Experimental results showed that the new polymer drilling muds have excellent filtration control behaviours and thermal stability at all the temperatures. The three already existing muds showed thermal degradation at 250oC, 350oC and 450oC temperatures. The values of flow index were found to be less than 1.0 showing pseudoplastic flow behaviour of the muds. Consistency index, Shear stress and yield stress increased with increase in concentration. Viscosity decreased with increasing shear rate showing shear thinning behaviour of the muds. The highest percent weight loss of 65.70% and lowest percent weight loss of 10.34% were obtained with one of the new starch blends and one of the already existing starches respectively for biodegradability. The polymer drilling muds obeyed Henri Darcy and API models for filtration as well as power law and Herschel Bulkely models for fluid rheology. The results from Matlab model showed that the values of coefficient of regression, (R2 ) and the Sum of Squared Errors, (SSE) were respectively close to “1” and “0”signifying good fit for all the new muds. The behaviours of the muds showed that there is proximity between the Matlab‟s modelled results and the experimental results based on the already existing models. Therefore, the polymer muds containing the new starch blends are purer, more suitable and more environmentally friendly than the already existing muds. The new muds are therefore recommended to be used for drilling operations in all areas including high temperature and environmentally
Open Access
Analysis of response capacity of rural households to selected poverty intervention programmes in Imo State, Nigeria
(Federal University of Technology, Owerri, 2016-11) Ajaero, Joseph Onyewuchi
This study analysed the response capacity of rural farmers to National Fadama Development Programme (NFDP) and National Special Programme for Food Security (NSPFS) in Imo State, Nigeria. The specific objectives were to; categorize and describe response capacity of rural farmers, assess the level of knowledge of rural farmers’ to the rural poverty intervention programmes, determine the relationship between behavioural process and response capacity, determine factors that affect positive response to rural poverty intervention programmes, ascertain the rural farmers’ perception of agricultural extension effectiveness on positive response to rural poverty intervention and identify the perceived constraints to desirable response to poverty intervention programmes in the study area. Data were collected through the use of standardized questionnaire. Descriptive statistics (frequency distribution, mean score and percentages) and inferential statistics (multinomial logit regression, Chi-square and Univariate analyses) were used to analyse the data generated. The mean age was 50.7 years. Majority (57.9%) of the rural households in the study area were male with mean household size of 6 persons. The results further showed that majority (86.5%) of the rural farmers were engaged in crop production. The mean net annual farm income was N97041.63. Majority (90.6%) were members of social organisation especially cooperative societies (65.1%). A total of 97.4 percent had one form of formal education or the other. Extension agents (71.7%) were identified as their major source of agricultural information. The study found that majority (58.3%) of the rural farmers had high level of knowledge about NFDP while only 31.7% had high knowledge level about NSPFS. Majority (64%) of the rural farmers perceived extension service as not effective in activities in rural poverty intervention programme. The study also revealed that behavioural process has a positive and significant effect on response capacity at p0.05 critical level with a regression coefficient of 0.693 and R 2 of 0.894. Majority (65.7%) of the rural farmers in the study area fell within the desirable response capacity, which is a sociological prerequisite for participation in rural poverty intervention programme. The multinomial logit regression results revealed that probability of being in the desirable response category increases with net annual income (4.055) and farmers’ self esteem (0.373) while sex (4.645), level of education (9.300), extension effectiveness (38.569), number of information sources (11.772) and distance to LGA headquarters (11.111) each decreases the probability of being in desirable response category to rural poverty intervention relative to the reference category. The constraints militating against positive response to NFDP and NSPFS poverty intervention programmes included institutional bottlenecks of the programmes (M = 3.32), lack of access to credit (3.19), lack of capital (M = 3.00), stringent requirements for qualification to participate in the programmes (M = 3.16), lack of awareness of NSPFS (M = 2.98) and lack of awareness of NFDP (M = 2.56). The study recommends that government should reposition extension service to be effective in services delivery to targeted beneficiaries in future poverty intervention programmes. Also the existing public agricultural extension service, Imo State Agricultural Development Programme (IMADP) should work in synergy with programme-donor agencies in order to carry out good sensitization campaigns at the inception of any rural poverty programme to create awareness and lay the foundation for desirable response required for the programme success.
Open Access
Spatio-temporal characterization and dynamic modelling of ambient air quality in Imo State
(Federal University of Technology, Owerri, 2016-12) Ibe, Francis Chizoruo
Spatio-temporal characterization and dynamic modelling of ambient air quality were carried out in Imo State, Nigeria. The study was aimedat evaluating the ambient air quality of Imo State and to present a dynamic model for prediction of atmospheric dispersion and concentration in the study area. Six atmospheric pollutants includingPM10, NO2, SO2, VOC, H2S and CO were measured using Haze Dust Particulate Monitor (10µm), Gasman Air Monitors, Aeroqual Series 300 and Ibrid MX6. The meteorological parameters, wind speed, ambient temperature, air flow, wave height, and wind direction, were measured with Multifunctional Microprocessor DigitalAnemometer, while difference in temperature of wet and dry bulb hygrometer was used to locate the relative humidity from a psychrometric chart and elevation was with GPS map 76.Air quality monitoring was conducted in wet and dry seasons, three times a day (morning, Afternoon and evening) in 4 locations with a total of 16 air sampling sites within the months of November, 2014 to June, 2015. The result showed that the mean concentration of the air pollutants in dry season ranged as follows: PM10 (5.70 – 8.38) mg/m3 , NO2 (0.37- 0.53) ppm, SO2 (0.29- 0.61) ppm, VOC (0.47 - 1.14)mg/m3 , H2S (0.01 – 0.05) ppm and CO (0.29– 49.52) ppm, while in wet season the values were in the range; PM10 (4.91– 7.34) mg/m3 , NO2 (0.43- 0.59) ppm, SO2 (0.43- 0.60) ppm, VOC (0.25- 1.06) mg/m3 , H2S (0.00 – 0.01) ppm and CO (26.42 – 41.77) ppm.Spatial variation of the air pollutants was observed in the study area as revealed by the GIS analysis which was illustrated with spatial variation maps, contour and 3-D surface plots.The Box and Whisker plots showed the characterization and distribution of the data in terms of lower quartile, upper quartile, median, minimum and maximum values. It indicates elevated level of CO, PM10 and SO2 in the afternoon and evening, higher concentration of VOC and H2S in the morning and NO2 showing significant values in the morning and afternoon. The Dynamic models in most locations showed high R2 indicating significant influence of the meteorological factors and previous day concentration (PDC) of the pollutants. The time series models showed that the concentration of the pollutants fluctuated within the period of study. The windrose models revealed the dominant wind speed, direction of dispersion and transportation of the air pollutants. One-way ANOVA (p <0.05) revealed that the difference in mean values of the air pollutants were not statistically significantin some locations due to the influence of season, meteorological factors, location and time of measurement, while that of the meteorological variables were significant in some locations . High correlation was observed between NO2 and SO2, wind speed and air flow, while weak correlation was recorded between PM10 and SO2, VOC and CO, temperature and relative humidity. Hierarchical Cluster Analysis (HCA) grouped both the air pollutants into two major cluster and meteorological parameters into two clusters. The Principal Component Analysis (PCA) revealed two coherent components existing among the air pollutants and between the meteorological variables. The multivariate plots indicate that the meteorological parameters have great influence on the air pollutants.The mean concentration of the air pollutants obtained exceeded the Nigerian National Ambient Air Quality Standards (Nigerian NAAQS) and United States of America NAAAQS while NO2 and SO2 are within the permissible limit in some of the monitoring stations. Air Quality Index (AQI)analysis is within 51 – 300 (moderate – very unhealthy). In conclusion, the study has established the spatial and temporal attributes of the measured ambient air pollutants, the dynamics of atmospheric dispersion and prediction of air pollution events in the study area. The observed AQI within the study area is of great concern and therefore requires serious attention by environmentalists, researchers, regulatory bodies, and of course the government at the various levels.
Open Access
Effects of some indigenous plant extracts on carbon tetrachloride-induced hepatic fibrosis in male wistar rats
(Federal University of Technology, Owerri, 2017-11) Ukairo, Doris Ifeyinwa
Plant-derived drugs and antioxidants are widely used in the management of chronic liver diseases and cirrhosis. Methanol extracts of raw (R) and cooked (C) samples of Sphenostylis stenocarpa (SS), Chromolaena odorata (CO), Buccholzia coriacea (BC) and Monodora myristica (MM), at doses of 250 mg and 500 mg per kilogram body weight of male Wistar rats were evaluated for their effects on carbon tetrachloride (CCl4)-induced hepatic fibrosis. One hundred and sixty (160) rats (155 ± 20 g) were distributed into twenty groups of eight rats each; representing normal control, olive oil control, negative control, positive control (silymarin) and various groups treated with raw and cooked extracts of the samples at the stated doses (RSS250, RSS500, CSS250, CSS500, RCO250, CCO250, etc.). The extract-treated groups were pre-treated with their respective extracts twice a week for four weeks before the introduction of toxicant. All the groups except normal and olive oil controls were intraperitoneally injected with 1 mg/kg of CCl4/olive oil (1:1 v/v) mixture twice a week for four weeks with continued extract-treatment. Liver and kidney damage were assessed using various biochemical parameters, such as the enzymes; alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phospatase (ALP), lactate dehydrogenase (LDH) activities, as well as bilirubin, urea, creatinine, electrolytes and malondialdehyde (MDA) concentrations. In addition, CCl4-induced pathological changes were evaluated by histopathological studies and the expression of collagen as evidence of induced fibrosis confirmed by immunohistochemistry. Treatment with methanol extracts of SS, BC and MM especially at low concentrations significantly (P<0.05) ameliorated the effects of CCl4 intoxication by reducing hepatic enzymes and LDH activities and as well increased other parameters. The effects of the extracts were attributed to the phytochemical compositions of the plants. The findings provided evidence to show that methanol extracts of SS, BC and MM at low concentrations possessed antifibrotic and hepatoprotective properties against CCl4-induced liver injury in male Wistar rats through their antioxidant and anti-inflammatory activities.
Open Access
Effect of processing and storage on the retention of flavour compounds in Piper nigrum L. and Aframomum danielli spice sample
(Federal University of Technology, Owerri, 2018-07) Adedokun, Isiaka Ishola
Effects of processing and storage on the retention of flavour compounds in Piper nigrum L(‘black pepper’) and Aframomum danielli seeds spice samples was studied. Mature berries of Piper nigrum L. and pods of Aframomum danielli were procured from point of harvest and subjected to post-harvest treatment and dried respectively. Dried spice seeds were pulverize into powder prior to extraction of flavour compounds with six different solvents. The solvent extraction process was at 1:5w/v ratio of spice powder to solvent and the extract was vaporized to obtain 1:1w/v flavour extract from each solvent for preliminary investigation of flavour constituents. Three processing methods were applied for each spice: (i) pulverized sample, (ii)extract with aqueous 40% ethanol sample and (iii) ethanol extract-coated on suitable carriers(potato grits and rice grits). The pulverized and 40% ethanol extract were stored in amber coloured glass bottles while extract on suitable carriers were packaged in high density polyethylene bags. Each sample was stored at ambient temperature (30+ 3o C) for six months and analyzed at intervals. GC-MS was used to determine the chemical constituents and to monitor the flavour profile during storage. The results of moisture content, specific gravity, phytochemicals and flavour compounds in solvent extract samples were significantly (p<0.05) varied. Specific gravity of absolute ethanol flavour extract was 0.784 in Piper nigrum L. and 0.612 in Aframomum danielli and were significantly higher (p<0.05) than other solvent samples. In Piper nigrum L. n-hexane flavour extract showed 86 GC-MS peaks and 30 Major Flavour Principles (MFPs). This was followed by acetone extract with 78 GC-MS peaks and 26 MFPs. GC-MS peaks of 56 with 18 MFPs in absolute ethanol, 59 GC-MS peaks with 25MFPs in 40% ethanol extract, 42 GC-MS peaks with 20 MFPs in methanol and water extract had the least 5 peaks and 3MFPs. Piperine was the high major flavour principles (MFPs) in Piper nigrum L. flavour and the values ranged from 2.43% in hexane extract to 17.50% in ethanol extract. However 10 GCMS peaks and 8 MFPs were found in absolute ethanol extract of Aframomum danielli, 9 GC-MS peaks and 7 MFPs in 40% ethanol extract sample, 22 GC-MS peaks and 6 MFPs in methanol sample, 28 GC-MS peaks and 7 MFPs in acetone flavour extract, 84 GC-MS peaks and 12 MFPs in hexane flavour extract and none in water extract of Aframomum danielli. The highest major flavour principle ‘MFPs’ of Aframomum danielli solvent extracts was eucalyptol with values ranging from 20.53% to 62.05%. Percentage retention (PR) of core volatile flavour principles in extract coated in suitable carriers in both spices reduced when the ratios of coating materials (rice grits and potato flour) increased in the encapsulated samples. Furthermore, the percentage retention of core volatile flavour principles in spice products samples studied varied at 6months storage. However 40% ethanol extract of Piper nigrum product sample (PP-EB) had the 91.31% piperine retention higher than other spice products samples in Piper nigrum while pulverized of Aframomum danielli product sample (AFD-PB) showed 83.46% highest eucalyptol retention among Aframomum danielli spice products. Sensory evaluation identified 5 and 8 sensory attributes of Piper nigrum and Aframomum danielli spice flavour product samples respectively. Pearson correlation value of 0.927 in Piper nigrum and 0.671 in Aframomum danielli for flavour pungency was the highest among other sensory attributes to overall acceptability. The total viable counts of fungi and bacteria were higher in raw spices than processed powder. Initial bacterial load was 1.21 x 109 cfu/g in black pepper berries and 7.8 x 108 cfu/g in Aframomum danielli raw seeds. These reduced to 0.9 x 103 cfu/g and 1.21 x 103 cfu/g pulverized spice powder.
Open Access
Effect of processing and storage on flavour retention of xylopia aethiopica and curcuma longa specie samples
(Federal University of Technology, Owerri., 2018-07) Ibe, Chidiuto
The main objective was to determine the effect of processing and storage on flavour retention of Xylopia aethiopica and Curcuma longa. Spice products were processed into powders and six different solvents (absolute ethanol 98.99%, 40% ethanol, methanol, acetone, n-Hexane and water) were used to extract the bioactive compounds in the spices. The spices were separately processed into six different spice products that included spice powder, liquid spice extract and four encapsulated spice samples with wheat and yam grits as carriers at the ratios of 1:2 and 1:3 spice extract to carrier.They were packaged in amber coloured plastic bottles and stored at ambient temperature (28±30 C) for six months. The essential oils obtained by different solvent extractions from spiceswere analysed by gas chromatography-mass spectrometry (GCMS) while the curcumin content of the C. longa for the different solvent extracts were analysed with Ultra-fast liquid chromatography (UFLC). Microbiological analysis were conducted on the fresh and dried ground spices for initial microbial load determination. Sensory evaluation were also carried out on the spice samples. The results of phytochemicals on the two spices identified the presence of alkaloids, flavonoids, phytic acid, saponins, tannins and oxalates. Different compounds were obtained from the different solvent extracts of X. aethiopica but the most predominant common flavour compounds found were two monoterpenes and one diterpene which included beta-pinene (15.48% in absolute ethanol, 20.28% in 40% ethanol, 8.11% in acetone, 14.03% in methanol but not detected in n-Hexane and water extracts), beta-phellandrene (18.93% in absolute ethanol, 23.93% in 40% ethanol, 21.54% in methanol, 7.38% in acetone, 12.09% in n-Hexane and 4.29% in water) and andrographolide (9.66% in absolute ethanol, 8.06% in 40% ethanol, 7.67% in methanol, 7.29% in acetone, 4.20% in n-Hexane and was not detected in the water extract). The major compounds identified by GC-MS analysis of C. longa were sesquiterpenes (40.55%), fatty acids (27.16%), diarylheptanoid (12.02%) and steroids (4.35%). The following curcumin concentrations were obtained in the different solvents extracts; absolute ethanol (53.27%), 40% ethanol (10.74%), methanol (12.46%), acetone (14.15%), n-Hexane (3.77%) and water (2.29%). At the end of the 6 months ambient storage of X. aethiopica spice products, the 40% ethanol extract had the highest concentration of beta-phellandrene with 19.56%, the concentration of betaphellandrene was significantly (p<0.05) higher when in wheat grit carrier (13.54%) at ratio 1:2 after 6 months compared to when it was in yam grit carrier (9.77%) at ratio 1:2. However, the 1:2 ratio retained more than the 1:3 ratio in both carriers. But in C. longa spice products, at the 6th month of storage the spice powder had the most concentration of Curcumin with 39.67%, the yam grits carrier retained more than the wheat grits while the 1:2 ratio retained more than 1:3 ratio in both carriers. The total fungal counts for C. longa ranged from 2.0 x 105 cfu/g in the ground sample to 3.2 x 108 cfu/g in the raw sample and 2.20 x 105 cfu/g in the ground X. aethiopica sample to 5.1 x 108 cfu/g in the raw sample. The common microflora of the spices were; Saccharomyces cerevisiae, Enterococcus, Bacillus, Lactobacillus and Streptococcus for C. longa and Saccharomyces cerevisiae, Enterococcus, Penicilliumnotatum, Bacillus, Lactobacillus, Staphylococcus and E. coli for X. aethiopica The scores of the sensory quality attributes of the spices showed that the 40% ethanol extract was the most acceptable sample. The sample was recommended for a greater number of different foods and drinks such as rice, meat, sauce, tea, akamu/pap, baked products, yoghurt, alcoholic and non-alcoholic beverages for C. longa and meat, porridge, pepper soup, Igbo soup, Yoruba soup, Hausa soup and alcoholic beverages for X. aethiopica.
Open Access
Production, characterization and si engine performance evaluation of palm bunch bioethanol
(Federal University of Technology, Owerri, 2018-09) Onuoha, Lovelyn Ngozi
This study investigates bioethanol production from waste palm bunch. This project falls under the focus category of waste to energy as it addressed issues relating to conversion of waste which poses a disposal burden to energy. Physical properties of the feedstock which was collected from Siat Nigeria Limited Ubima, Rivers State were determined to consist of 57.44 % cellulose, 16.89 % hemicelluloses, 15.87 % lignin and 5.57 % ash. The raw material was prepared by physical pretreatment, chemical hydrolysis, fermentation and distillation to obtain bioethanol fuel. The presence of bioethanol and its optimum preparation condition were established from a preliminary experiment in the laboratory. The physical pretreatment which is the most critical step being labour intensive reduced the feedstock size to 850 microns. Hydrolysis carried out with H2SO4 on 200 g of the pretreated raw material gave optimum yield of 27 g/L xylose and 49 g/L glucose with 1.2 % acid load for 30 minutes at 160 0C, giving a total sugar yield of 76 g/L. Fermentation of the optimum hydrolyzate with S. cereviasea for 72 hours at room temperature gave optimum bioethanol yield of 32 g/L. A charcoal fueled distiller of 20 L feed/h loading capacity, 8.95 kW reactor power rating was fabricated based on the preliminary data. The distiller was used to distill bioethanol from the optimum fermentate, at 75 % combustion efficiency. 817 ml of bioethanol was obtained in 115 minutes at actual combustion efficiency of 55 % and power rating of 12.2 kW. The distiller has high flexibility of handling various boiler feed using different biomass solid fuel in the reactor. The produced bioethanol elemental analysis conforms to ASTM D4806. Fuel blends of the bioethanol with pure petrol were characterized based on ASTM D4814. At 15 0C, density of pure petrol increased from 744.73 kg/m3 to 782.5 kg/m3 with increase in bioethanol while E100 has 791.13 kg/m3 . Octane number of pure petrol increased with increase in bioethanol in the blends. Flash point of all the blends is below 15 0C making them susceptible to ignition and has the chance of flammability hazard. The vapour pressure of pure petrol increased with 10 % bioethanol but decreased with increase in bioethanol from 20 %. Bioethanol content above 10 % increased viscosity of pure petrol. Calorific value of pure petrol was decreased with increase in bioethanol percentage in the blends. The suitability of the fuel blends as SI engine fuels were studied at full, 3/4 and 1/2 engine loads; and at 2500 rpm, 3000 rpm and 3500 rpm engine speeds. The performance evaluation was carried out in a single cylinder, four strokes, air cooled Petrol Engine. The performance characteristics observed showed that, blending pure petrol with the bioethanol increases the brake power, brake specific fuel consumption and brake thermal efficiencies. The engine performance results recommend blending pure petrol with 10 – 30 % of the bioethanol. Thus, the need of bioethanol for energy sector could be met by using Nigerian waste palm bunch as raw material.
Open Access
Comparative analysis of techniques for estimating geohydraulic properties and aquifier vulnerability in Imo River Basin, SouthEastern Nigeria
(Federal University of Technology, Owerri, 2019) Emberga, Terhemba Theophilus
Comparative Analysis of Techniques for Estimating Geohydraulic properties and Aquifer Vulnerability in Imo River Basin, Southeastern Nigeria was carried out to determine the most suitable and cost effective techniques for the determination of hydraulic properties and groundwater vulnerability in the Imo River Basin. The basin which lies between Latitudes 4° 38' and 6° 01' N and Longitudes 6° 53' and 7° 32' E with an area extent of about 9100 km is underlain by the Ajali, Nsukka, Imo Shale, Ameki, Ogwashi-Asaba and Benin Formations. Five hundred and sixty-nine (569) vertical electrical soundings (VES) using the ABEM Terrameter (SAS) 4000 with maximum electrode spacing of 1000 m were acquired in the study area. Thirty (30) parametric soundings out of the entire VES data points were carried out in the vicinity of existing boreholes for comparative analyses and quality control. Twenty (20) sandstone samples collected from the six (6) formations were sieved and the resulting data processed to obtain hydraulic conductivities of aquiferous units. Comparatively, Da-Zarrock parameters (transverse unit resistance and longitudinal conductance) were used to determine aquifer depth, thickness and hydraulic characteristics from VES Data. Additionally, estimates of hydraulic conductivity were made using the techniques of Niwas & Singhal and the Heigold’s method. A New model that is Novel and formation sensitive was also developed using resistivity and existing pumping test data. The mean aquifer resistivity revealed 1397.96 in Ajali, 2116.92 in Ameki, 2188.15 in Benin, 632.55 in Imo shale,1355.08 in Nsukka and 2072.91Ω m in Ogwasi-Asaba Formations while the mean aquifer thickness in Ajali revealed 40.83, while those in Ameki were 42.68, 39.38 in Benin, 26.78 in Imo Shale, 36.34 in Nsukka and 37.39 m in Ogwasi-Asaba. The study also revealed the aquifer thickness of 122.04 in Ajali, 121.86 in Ameki, 114.46 in Benin in 73.73 in Imo shale, 36.92 in Nsukka and 109.66m in Ogwasi- Asaba. The results of the hydraulic conductivity and that generated with the model revealed average values of 13.19, 1.74 and 4.62 m/day respectively. The hydraulic conductivity values estimated using the empirical formulae of Hazen, Kozeny-Carman, Breyer, Slitcher and USBR have mean values of 1.55, 256.8, 0.58, 2.82 and 0.046 m/day respectively. These results were validated with the existing pumping test data using Artificial Neural Networks. Mean Transmissivity (Tmean) and Storativity values computed from the hydraulic conductivity data revealed values of 140.8 m2 /day and 5.3 × 10-5 , respectively for the aquiferous units in the Ajali Formation. In the same vein, Tmean of 193.5 m2 /day and mean storativity of 5.54× 10-5 were estimated for Ameki Formation aquifers, while Benin Formation aquifers revealed Tmean of 784m2 /day and mean storativity of 5.11 x 10-5. The aquifers in the Imo Formation have a mean transmissivity Tmean = 205.2 m2/day with a mean storativity of 3.48× 10-5 . The aquifers in the Nsukka Formation have a mean transmissivity Tmean = 211.5 m2 /day with a mean storativity of 4.8 × 10-4 while the aquifers in the Ogwasi/Asaba Formation have a mean transmissivity Tmean = 100.2 m2 /day with a mean storativity of 4.86 × 10- 5 . The vulnerability of the aquifers evaluated using Geologic (DRASTIC and GOD) and Geophysical (Integrated Electrical Conductivity, IEC) models generated vulnerability maps which displayed areas within the northern part of the study area to have low and moderate vulnerabilities while the southern part has aquifers with high vulnerability to pollution. The estimated percolation time of contaminants using IEC model revealed that it will take contaminants from several months to about 25 years to get to the groundwater system in the study area. The good correlation of hydraulic conductivity results between the new model and existing pumping data implies that generated model can substitute the laborious and expensive pumping tests of boreholes in areas with similar geologic formations.
Open Access
Assessment of the impact of concessioning on the productivity of Nigerian Ports
(Federal University of Technology, Owerri, 2019-02) Nze, Obiageli Nneka
This study assessed the productivity of Nigerian ports. The study adopted ex post facto design. Using ship traffic, vehicle traffic, berth efficiency, turnaround time as input explanatory variables and output factors as average throughput to compare the pre concession and post concession. The six Nigerian ports: Tincan Island Ports, Apapa Port, Port of Delta Warri, Calabar Port, Rivers Port and Onne Port were sampled. A survey was conducted on 50 stakeholders in the port sector to determine the factors contribute to port’s productivity. These factors were examined for each of the ports under study and were analysed with t-test using a hypothesized mean. Secondary data was extracted from National Bureau of Statistics (NBS) Annual Reports, Nigeria Port Authority (NPA) Annual Reports, and Central Bank of Nigeria (CBN) Annual reports.From the t-test, the factors with p-value less than 0.05 were the significant ones. Among the factors influencing the productivity of the ports in Nigeria are predetermined operational problems, frequent congestion of ship, poor inboard services and high cost of documentation etc. Using Data Envelopment Analysis as the fundamental analytical tool to test the most efficient port before and after the concession period. The result reveals that Onne Port and Tin Can Island Port productivity increased significantly after the concession. However, Rivers, Delta, Calabar and Apapa Ports experienced unstable efficiencies in the post concession era. The implication is that concession of Nigerian Ports have favourable effect on Onne Port and Tin Can Island Port and less favourable to Rivers, Delta, Calabar and Apapa Ports. In line with the result, it was recommended that since it was observed that there was element of improvement in the post-concession period of operation at Nigerian Ports, we recommend adequate provision of superstructure for the private operators to utilized them and compliment their infrastructure with them towards the achievement of goals of concession. However, concessioning is a good instrument to improve productivity in Nigerian Ports and requires continuity among Nigeria Ports. We recommend adequate and necessary cargo handling equipment at Ports that experienced fluctuating efficiency.
Open Access
Transient performance evaluation of diurnal heating and nocturnal cooling of water using a hybrid flat-plate solar collector/radiator
(Federal University of Technology, Owerri., 2019-02) Nwaji, Godswill Nnabuihe
Present energy dependence on fossil sources has been identified as the primary cause of the twin menace of global warming and climate change, hence the focus of the ensuing investigation on renewable energy resources to address the current environmental concerns. The transient performance evaluation of a hybrid solar collector/nocturnal radiator (SCONOR) for diurnal water heating and nocturnal water cooling is thus presented. The mathematical models of the physical system are based on the heat transfer mechanism in the SCONOR-bond-tube-water arrangement while for accumulative heating and cooling performances the models were based on lumped energy equations in the SCONOR and multi-zone stratification models in the thermal energy storage tanks. The resulting equations were discretized using finite element numerical scheme for ease of implementation in a digital computer. The transformed equations were solved using a scripted code written with FlexPDE finite element model builder and numerical solver version 7.12. The numerical results obtained from the models were compared with experimental data from literature sourced from three different climatic conditions. In the transient diurnal heating mode, the time of occurrence of SCONOR, bond, tube and water peak temperatures were accurately predicted while a mean deviation of 4-8.6oC was observed between the reported data and numerical predictions. For the transient nocturnal performance evaluation of the SCONOR, the model results closely matched experimental results with a mean deviation of less than 0.2oC, given that the initial conditions varied at about 7oC which was maintained throughout the nocturnal period with minimal fluctuations. The model results from a 24-hour performance cycle covering diurnal heating, cool down and nocturnal cooling of the SCONOR closely matched experimental results for the absorber and radiator functions of the hybrid system with mean deviations of 3-5 oC in the diurnal heating mode and 0.2-0.4oC in the nocturnal cooling mode. The accumulated performance results during the diurnal thermal storage and nocturnal thermal storage were also compared with available experimental data from literature, and the results show good agreement with mean deviations of 0.2-5 oC and 7oC during heating and cooling respectively. The thermal energy accumulated in the hot tank during diurnal heating maintained the modelled room temperature at approximately 5oC above ambient during the cold harmattan night and that accumulated in the cold storage tank maintained the modelled room temperature at 5.7oC below ambient during the hot day. From parametric analyses, the optimal design parameters are 0.26m, 0.003m, 0.1m, and 1 for the bond width, bond thickness, riser tube spacing and number of windscreen respectively. The overall results show that the developed models are useful design tools for the integrated diurnal water heating-and-nocturnal water cooling.
Open Access
Development of natural antioxidant active polymer package from extracts of monodora myristica (Ehuru) for lipid food preservation
(Federal University of Technology, Owerri, 2019-03) Nwakaudu, Adanze Angela
A natural antioxidatant active polymer package film was developed for lipid food preservation. Three active package films were produced, namely: film containing only ehuru antioxidant extract (EAE), α-tocopherol (AT) and a blend of EAE/AT using casting method. Different percentage compositions (0 - 5% w/w) of EAE were incorporated into polysulphone (PSF) resin, while 5% AT was incorporated into PSF resin which served as standard. A 5% equal combination of EAE/AT was also added to PSF to produce package film. Mechanical, thermal, morphology and barrier properties of developed films as well as the pure PSF film were determined and compared. The antioxidant ability of the developed films was investigated using 2,2- Diphenyl-1-picrylhydrazyl (DPPH) method. The ability of the films to stabilise lipid (peanut oil) against oxidation was tested by packaging peanut oil with the active films. The peroxide value (PV) and p-anisidine value) of the actively packaged and stored peanut oil were determined. Results of the barrier properties showed that the rate of permeation of gas in the EAE active films was shown to be reducing significantly (from 0.1256 to 0.0277)cm3 /s as concentration of EAE incoporated in the film increased, while films with blend of EAE/AT produced higher permeable films of (0.1079 cm3 /s ). AT film was the most permeable (0.2209 cm3 /s). The spectrum of the FT-IR analysis confirmed the presence of esters, amides and amines in the absorption peaks of 3526, 3302.4 and 3697.5 cm-1 . Absorption peak of 1736.9 cm-1 for the ester and 1684.8 cm-1 for amide. The SEM microstructure revealed that the porous film of the pure PSF reduced as concentration of the EAE added increased from 0% - 5%. The incorporation of 5% EAE , produced very smooth and homogenous surface film without apparent phase separation. The melting point of EAE active film was established at 210 oC compared to 230 oC for the pure PSF. The AT active firm recorded a higher melting temperature of 247 oC. The oxidation results showed a significantly (p < 0.05) lower rate increase in oil samples packaged with the developed films than the control sample. Results also revealed that at the end of nine weeks of storage, peanut oil packaged with active film containing only EAE natural antioxidant showed the lowest lipid oxidation by recording the lowest peroxide and p-anisidine values of 9.82±1.50 meq/kg and 30.45±0.00 respectively. The effect of concentration of the EAE on the oxidation of the peanut oil showed that their is no signifcant difference (p > 0.05) in the 2.5% and 5% EAE on the PV and P- anisidine values of the packaged oil sample, hence concentration between 2.5 and 5% could be used for the active film. Considering the mechanical properties of the active package, 5% EAE produced the most flexible film with percentage elongation at break (EAB) of 3.221% and best antioxidant activity of 48.097%. The overall results showed that the developed Ehuru antioxidative package had demonstrated the potential of slowing down the lipid oxidation and therefore could be used to preserve lipid foods like peanut oil.