Since the drought of the early 1970s, the Niger part of the Lake Chad Basin has undergone significant changes. Its environment has evolved considerably, with land cover and use (cultivation, grazing) experiencing significant momentum. This change in land use has led to a decrease in natural habitats (savannas and forests), thereby increasing the vulnerability of soils to erosion agents. Erosion dynamics (wind and water) have also undergone an evolution. The resulting erosive response to these changes was discussed and particular attention paid to the gully network dynamics and the Komadougou Yobe banks during the periods of 1957-1975 and 1975-2007. Three maps of gully dynamics were produced. Shreve order gullies remained constant and equal to two (2) between 1957 and 1975, going up to 4 in 2007. The gully network total length has evolved. From 1957 to 1975, it multiplied by four (4) and from 1975 to 2007 by three (3) or by nine (9) from 1957-2007. The two Komadougou meanders (B1 and B2) studied cartographically showed a strong momentum. Thus, at B1 and B2 level, a 120 m and 92 m bank recession was observed between 1975 and 2007 and the wavelengths have respectively increased from 196 m and 1083 m in 1957 to 349 m and 943 m in 2007. A tendency to overlap is thus observed at these meanders. If this degradation acceleration trend continues, we will witness a short term rural exodus, the abandonment of villages and competition on land that can lead to internal as well as extraterritorial conflicts.
This paper recognized motivation (intrinsic or extrinsic to workers) as an instrument for efficient and effective execution of a project. The paper examined if workers are highly motivated, the motivational factors that mostly affect workers’ performance, the effect of motivation on workers’ performance in project execution, and the relationship that exist between Project execution and workers’ motivation in Bayelsa Plastic Industry, Yenagoa Bayelsa state, Nigeria. The paper sought answers to research questions by employing survey design, using multistage sampling technique to select respondents. Data was elicited from 61 respondents with the help of a 14-item questionnaire and personal interview. The respondents consisted of management and staff of the establishment under study. Data for this study were analyzed using descriptive statistics, and chi-square (X2) was used to test hypotheses at 5% significant level. The study revealed that if workers were poorly motivated, workers preferred extrinsic to intrinsic motivational factors and that there is a positive and significant relationship between workers’ motivation and performance in project execution. The paper recommended, a consistent study and assessment of individual worker’s needs, wants, desire, personal interest, aspirations, and their performance level in order to know what motivate workers at every point in time and therefore take necessary actions to stimulate their efforts towards high standard performances, efficient, and effective project execution, timely project completion, and reward them accordingly. Motivation plan and budget should be included in company’s budget, corporate policy and plan.
An investigation on the compressibility and settlement duration of a lateritic soil of Yaoundé, Cameroon, was performed to check on its ease to carry loads of civil engineering structures. The increase in settlement with water content is more accentuated with a stronger load than a weaker one. The compaction also considerably decreases the compressibility of these soils, rendering the action of water almost null on the variation of settlement except when the compaction is not made with the optimum Proctor. These significant observations compel us to consider only, for a lateritic soil or another soil, the compressibility characteristics under immersion conditions. The findings of this work agree with the principle of the odometric test described in the French Standard NF P 94 900.
Meteorological events are posing serious environmental challenge especially in freshwater pollution control. Imo River serves as a source of water for domestic uses, agricultural irrigation, fishery and recreational activities and exposed to pollution. Surface water samples were collected in dry and rainy seasons for 2 years, with the aid of 1-liter water sampling cans, from seven major human impacted points. Copper (Cu), zinc (Zn), oil and grease levels, all in mg/L, and pH were determined according to standard methods for the examination of water. There were significant variations in seasons (P=0.05) for oil and grease at all the locations; Ekenobizi (1.42±0.01-1.33±0.01), Udo (1.91±0.01-1.32±0.01), Owerrinta (3.74±0.57-2.36±0.01), Alulu (1.52±0.01-1.22±0.01), Owaza (6.73±1.00-4.22±0.01), Obigbo (4.55±0.01-3.13±0.01), and Akwette (13.75±0.0112.42±0.01). There were significant variations in seasons for copper (mg/L) (P=0.05) at Udo (0.09±0.01-0.06±0.01), Obigbo (0.14±0.01-0.11±0.01), and Akwette (0.19±0.010.15±0.01), while there were none (P=0.05) at Ekenobizi (0.13±1.060.06±0.01), Owerrinta (0.04±0.01-0.02±0.01), Alulu (0.01±0.01-0.01±0.01), and Owaza (0.30±0.10-0.24±0.01). There were no significant variations in seasons (P=0.05) for zinc at; Ekenobizi (0.03±0.01-0.02±0.01), Udo (0.04±0.01-0.03±0.01), Owerrinta (0.04±0.01-0.03±0.01), Alulu (0.04±0.04-0.01±0.01), Owaza (0.20±0.10-0.13±0.06) and Akwette (0.08±0.01-0.07±0.01) while there were significant variations in seasons (P=0.05) at Obigbo (0.14±0.01-0.12±0.01). There were significant variations in seasons (P=0.05) for pH at Ekenobizi, Udo, Owerrinta, Alulu, Owaza and Akwette, while, there were no significant variations in seasons (P=0.05) at Obigbo. Rainfall event contributed to the diffusion of pollutants into Imo River. Environmentally sustainable waste management programs and policies will prevent and protect it from subsequent destruction of the quality.
The study carried out seasonal study of some potentially toxic heavy metals: Lead, copper, cadmium, chromium, Nickel, and zinc in soils was conducted in five different vegetation zones of (Oli Camp) Kainji Lake National Park at two different levels. The vegetations are Isoberlinia woodland (S1), Terminalia macroptera woodland (S2), Burkea African/Detarium microcarpum woodland (S3), Riparian forest (S4) and Diospyrus mespiliformis (S5). The average values recorded for the wet season at 0-15cm depth in mg/Kg were in the order S1: Cd (10.73±2.00), Cu (34.21±0.00), Pb (20.08±3.40), Cr (39.39±2.30), Ni (29.14±2.90), and Zn (16.63±0.90); S2: Cd (11.56±4.00), Cu (24.11±2.78), Pb (18.97 ±4.50), Cr (47.34±6.70), Ni (12.03±3.45), and Zn (85.07±1.40); S3: Cd (7.17±2.45), Cu (47.52±2.10), Pb (19.73±1.00), Cr (37.48±2.22), Ni (24.67±1.20), and Zn (12.51±0.90); S4: Cd (8.00±1.30), Cu (35.21±0.00), Pb (19.74±1.00), Cr (37.96±3.00), Ni (10.93±1.00), and Zn (19.44±2.30); S5: Cd (1.95±0.00), Cu (7.92±0.40), Pb (10.74±1.20), Cr (40.35±2.60), Ni (25.27±1.80), and Zn (211.35±4.30). Generally, the trend showed a decreasing order for the sub surface soil (15-30 cm). Thus, the mean levels for the wet season at 15-30 cm depth followed the order of Zn>Cu>Cr>Ni >Pb>Cd in the vegetations investigated. The metal concentrations during dry season decreased at both depths with the ranges: Cd (0.74±0.02 to 2.26±0.01); Cu (2.02±0.02 to 6.72±1.10), Pb (9.18±3.40 to 18.48±1.45) Cr (23.55±2.00 to 51.94±2.70), Zn (160.06±0.56 to 323.08±2.10), and Ni (14.03±0.50 to 34.69±1.00) mg/g. The physico-chemical parameters of the soils in the wet and dry seasons was indicated that pH, 6.65 to 6.95 and 5.3 to 6.7; conductivity, 10.00±2.50 to 101.50±2.12 µScm-1; organic matter, 1.79±0.30 to 2.64 ±0.51 among vegetations studied at 0-15 cm and 15-30 cm depths respectively; this trend is similar to that of the dry season. The range 1.32±0.25 to 2.11±0.06 were recorded against wet season at both depths. Generally, the speciation result revealed that the levels of these metals studied in both seasons were associated in the order: Residual > carbonate > Fe-MnO > Exchangeable > Organic > Water soluble fractions. The finding in this study has led to the better understanding of the metal levels and their sequential interaction with one another. This will aid in determining and to create awareness about the metal ion status of Oli Camp in Kainji Lake Nation Park to stakeholders in order to mitigate against metal pollution as it is barely monitored.
Sucrose in the final molasses continues to be a source of major financial loss to sugar refineries worldwide. This study therefore aims at rectifying this anomaly. In this study, the final molasses exhaustibility was predicted using Adaptive Neuro Fuzzy Inference System (ANFIS) and Response Surface Methodology (RSM) based ondata generated from molasses sample collected from the recovery end of refining processes. The results show that both models are able to predict the final molasses exhaustibility with sufficient accuracy. The optimum sucrose recovery of 49.18% was achieved at the point when Brix0 is 96.00%, Purity of 65.00% and pH of 4.50. Also, both models agree on the combination of purity and pH as the two factors interaction that have optimal effect on the sucrose recovery. The correlation coefficient (R2) value obtained for ANFIS was 0.96 while that of RSM was 0.99. Thus, the RSM model has better prediction performance than ANFIS.
Aim: To synthesize and evaluate the effectiveness of two tetrapolymers as viscosifiers and filtration control agents in water-based drilling fluids for application in moderate saline and geothermal environment. Study Design: Orthogonal design involving monomer feed ratio, monomer solid content, initiator dosage, reaction temperature and pH was used to establish optimum synthesis conditions. Methodology: The tetrapolymers, TP1 and TP2, consisting of acrylamide-sodium 2-acrylamido-2-methylpropanesulfonate-sodium acrylate - N, N’-dimethyl acrylamide and acrylamide-sodium 2-acrylamido-2-methylpropanesulfonate-N-Vinyl-2-pyrrolidone-styrene were synthesized by free-radical polymerization. Monomeric compositions of the tetrapolymers were established by Fourier transform infrared spectroscopy. Rheological and filtration control properties were used as indicators to evaluate the effectiveness of the tetrapolymers in aqueous bentonite-based drilling fluids. Results: TP1 provided superior viscosity build-up efficiency and fluid-loss control (9.0 cm3/30 min - 10.0 cm3/30 min) compared to TP2 fluid losses ranging from 11.5 cm3/30 min to 21.5 cm3/30 min in salt-free bentonite muds at temperatures between 120ºC and 160ºC. Comparatively, TP1 reduced fluid loss to 4.0 cm3/30 min -12.0 cm3/30 min whilst TP2 exerted less filtration control of 12.0 cm3 /30 min -39.5 cm3 /30 min in salt contaminated muds. Conclusion: Both tetrapolymers were considered suitable drilling mud additives with TP1 demonstrating excellent viscosity build-up efficiency and fluid-loss control at elevated temperatures. TP2, however, exhibited better salt tolerance in aqueous salt medium and bentonite-based muds.
Aims: Software quality assurance is a formal process for evaluating and documenting the quality of the work products during each stage of the software development lifecycle. The practice of applying software metrics to operational factors and to maintain factors is a complex task. Successful software quality assurance is highly dependent on software metrics. It needs linkage the software quality model and software metrics through quality factors in order to offer measure method for software quality assurance. The contributions of this paper build an appropriate method of Software quality metrics application in quality life cycle with software quality assurance. Design: The purpose approach defines some software metrics in the factors and discussed several software quality assurance model and some quality factors measure method. Methodology: This paper solves customer value evaluation problem are: Build a framework of combination of software quality criteria. Describes software metrics. Build Software quality metrics application in quality life cycle with software quality assurance. Results: From the appropriate method of Software quality metrics application in quality life cycle with software quality assurance, each activity in the software life cycle, there is one or more QA quality measure metrics focus on ensuring the quality of the process and the resulting product. Future research is need to extend and improve the methodology to extend metrics that have been validated on one project, using our criteria, valid measures of quality on future software project.
A one dimensional model of population growth called logistic map can be used as platform for introducing beginners to the phenomenon of chaos and nonlinear dynamics. Despite the simplicity of logistic map, it has been used with success for the introduction of fixed point attractor, periodic and aperiodic responses, sensitivity to initial conditions, return map and bifurcation diagram. This understanding motivated the present study to develop two dimensional chaos diagram for a one dimensional logistic map as a way of introducing the beginners to the theories of fractals and chaos. Simulation of unsteady solutions, steady solutions and its corresponding Lyapunov exponent characterisation of logistic map were effected for selection of drive parameters for various grid resolutions, constant step size and at one grid point a time from 0.3 and 0.5 initial conditions. Validation were made of graphical results of parameter versus Lyapunov exponent and the parabola-attractors. The Lyapunov exponent characterisation results were grouped into three classifications: divergence, periodic and chaotic based on average Lyapunov value. There is qualitative agreement of validation results. The total number of grid points with divergence or periodic or chaotic response increases exponentially with increasing resolutions. The zoomed parameters counterpart has average 0%, 60% and 40% of divergent, periodic and chaotic results respectively across resolutions. The corresponding chaos diagram exhibited fractal structures by its layers of order within chaos as can be found in the bifurcation diagrams of nonlinear dynamical systems.
The chemical composition of groundwater samples in Yenagoa, Bayelsa State of Nigeria was experimentally investigated. Parameters as pH, temperature, redox potential, iron oxidizing bacteria, dissolved oxygen, iron and manganese were analysed. Results indicate the groundwater samples are rich in iron (3.28mg/L) above regulatory limits of 0.3mg/L. A treatment process was developed to improve the quality of the groundwater. The treatment process involves pre-treatment of the effluent with varying concentrations of KMnO4(1.5mg/L, 2.0mg/L and 2.5mg/L), and passed through a fixed-bed of bone char. The treatment process involving the use of 2.5mg/L dose of KMnO4 filtered through a fixed bed of bone char treatment showed iron and manganese reduction from 3.28mg/L to nil and from 1.03mg/L to nil representing 100% reduction for both metals. Iron oxidizing bacteria (IOB) was reduced from 106 cfu/ml to 101cfu/ml reduction representing 99.999% reduction. Values of pH, temperature, dissolved oxygen (DO) and redox potential were also affected. Results showed a good compliance with World Health Organisation (WHO) standards for drinking water. This means that the final effluent obtained is safe for human consumption and poses no aesthetic nuisance.