Archive for the ‘Faculty of Physical Sciences’ Category

HYBRID CODING METHOD FOR PLANNED COMPARISON OF TREATMENTS IN REGRESSION ANALYSIS.

January 25, 2017

Author: Etaga Harrison Oghenekevwe
Department: Statistics
Affiliation: Nnamdi Azikiwe University Awka

Coding in regression analysis has been widely used with varying applications. Various
coding structures have been developed in the past. Coding structures such as Dummy, Simple, Hermert, Reverse Hermert, Forward Differencing and Backward Differencing were developed to deal with specified (simple) hypotheses. A mixture of Dummy, Simple and Contrast coding was considered and studied to yield a hybrid coding which when applied correctly will not only yield the results of simple, dummy, or contrast coding but can also give other results. Existing data were used to illustrate the new method. Live Data on Rainfall, GDP, Oil and Non-Oil exports, Government expenditures obtained from the Central Bank of Nigeria Statistical Bulletin of year 2009 were subjected to the various methods for effective comparison of the existing methods. The results obtained showed that; Coding in regression analysis is superior to the chow-test as it was able to simultaneously test for the shift in intercept as well as in slope of given models. Regression was also better than the conventional ANOVA and t-test as it expressed clearly the magnitude of any observed differences. The new HCM was applied and the result obtained showed that it should be used to test specific hypotheses under planned comparison as it compared favourably with the dummy.

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3D SEISMIC INTERPRETATION OF ULA-FIELD IN NIGER DELTA, NIGERIA

January 25, 2017

Author: Umemeezie Ogechukwu Ursula
Department: Geological Sciences
Affiliation: Nnamdi Azikiwe University Awka

Three dimensional seismic interpretations have been carried out in the Ula-field of Niger-Delta Basin area to evaluate the reservoir characteristics of the producing formation and to predict the future performance of the well. The result of correlating the wells across the entire field shows that two potential reservoir were delineated namely N1 and P4. The quality of reservoirs decreases from Well-2 to Well-3, which implies that there is a good reservoir at Well-2 and Well-1 than at Well-3. The average thickness for the productive zone of N1 and P4 reservoirs is 239.37ft (72.96m). The localized faults were interpreted as normal faults which have some features of antithetic fault and synthetic fault. Time and depth contour maps of productive reservoir formations have been constructed using the time read directly from the respective tops of the two horizons and average velocities derived from interval velocities. Results also revealed that prospect zones tend to become thin in the northeast while it becomes thick in the southwest. Analysis of the field petrophysical distribution showed average values of volume of shale for each productive zone ranges from 18 to 32%; average values of porosity ranges from 22 to 25%, and average values of permeability ranges from 414 to 553mD. The total reservoir rock volume is calculated to be 848867.80 acres-ft while the calculated average area of the oil closure is about 3457.71acres.

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GEO-ELECTRIC INVESTIGATION FOR GROUNDWATER OCCURRENCE IN OTU-OCHA AND ENVIRONS ANAMBRA EAST LOCAL GOVT, AREA, ANAMBRA STATE, NIGERIA

January 25, 2017

Author: Onuorah Paschal Obiora
Department: Geological Sciences
Affiliation: Nnamdi Azikiwe University Awka

Geo-electrical survey of Otu-ocha and Environs in Anambra East Local Government was conducted using Vertical electrical sounding (VES) method. The main objective of this study is to determine the aquifer hydraulic properties and groundwater potential of the area. The resistivity imaging measurement employing Schlumberger electrode configuration was carried out using an ABEM Terrameter SAS 300.A total number of thirteen locations were run with Vertical Electrical Sounding and several layers of geo-electric units were obtained. The interpretation of the Vertical Electrical Sounding (VES) data revealed three to five geo-electric units with depth to the aquiferous layers ranging from 21.5m to 80.9m and resistivity of the water saturated layers varying between 16.1 Ωm and 3012 Ωm. The groundwater flow pattern of the study area was found to be radial as a result of water table mound formed towards the North West. Aquifer parameters such as transmissivity and hydraulic conductivity calculated from the VES result ranges from 0.4750m2/day to 61.461 m2/day and 0.0080m/day to 1.4907m/day respectively. The average transmissivity values of SE, SW, NE, and NW were given as 0.8495 m2/day, 3.0955 m2/day, 15.6481 m2/day and 21.2587 m2/day. This supports the occurrence of watertable mound around Otu-ocha and Umueri in the NW. This result shows that the water saturation is more at the watertable mound towards the North than other areas.

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HYDROGEOLOGICAL IMPLICATIONS OF GULLY EROSION IN ORLU AND ENVIRONS IMO STATE, NIGERIA

January 25, 2017

Author: Iheme Obinna Kenneth
Department: Geological Sciences
Affiliation: Nnamdi Azikiwe University Awka

Field geological mapping, hydrogeological and physiographic studies were done in the gullyerosion prone areas of Orlu and environs in Imo State, Nigeria. Three geologic formations were observed, namely the Ameki, Ogwashi-Asaba, and Benin Formations. About 27% of the gullies observed occurs in Ameki Formation comprising moderately to poorly sorted sand with hydraulic conductivity values ranging from 1 x 10-3cm/s to 5.4 x 10-2 cm/s and transmissivity values ranging from 1.21 x 10-2cm2/s to 5.61 x10-1cm2/s,while 73% occurs in Benin Formation comprising sands with hydraulic conductivity values ranging from 1.5 x 10-2cm/s to 6.6 x 10-2cm/s and transmissivity values of 1.11 x 10-1cm2/s to 6.50 x 10 1cm2/s. No gully was observed in Ogwashi-Asaba Formation, where more plastic soils exist. The grain size distribution curves indicate that about 80% (by weight) of the sands is medium to coarse sand, while 18% and 2% are fine sand and coarse silt respectively. The plasticity indices of the formations range from 24.83% to 48.42%. Factors responsible for the development and growth of the gullies were observed to include topography, rainfall, geology, hydrogeology and anthropogenic activities. Hydrogeochemical assessment of some water samples from public water supply sources indicate objectionable concentration of heavy metals such as Pb, Hg and Cd in groundwater, and Cu, Cd, Pb and Hg in surface water. The predominant water types include calcium-sulphate waters for groundwater, and sodium-chloride-bicarbonate waters for surface water. The observed consequences of gully erosion in the study area include loss of about 22km of arable lands and two major and six minor roads, loss of about nine residential houses, and pollution of public water sources. Possible remedial measures include incipient control, afforestation, multi-channelling of floodwater, use of catch pits, slope stabilization, promulgation of enforceable environmental policies, enforcement of existing ones and public awareness programmes.

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DYNAMIC PROGRAMMING MODEL FOR OPTIMAL INVESTMENT STRATEGY

October 26, 2015

Author: Mmagu, Callistus Chikelue
Department: Computer Science.
Affiliation: Nnamdi Azikiwe University, Awka

This study is aimed at formulating a dynamic programming model for optimal investment strategy which incorporates uncertainty in a probabilistic manner. An iteration technique of the dynamic programming is used to solve the model. The choice of Dynamic Programming is as a result of its recursive nature, whereby the problem is divided into multi-stages, with the result of each stage being used as an input into the next stage and so on, until the problem is solved. The study proves that the fundamental operations research tools of dynamic programming have wide application in the financial engineering especially now that there is a wide availability of powerful computing technology. This software package enables decision makers to critically analyze an investment opportunity before committing the firm’s long term assets to the project. Its use enables investors to minimize severity and frequency of risk in a period of uncertainty.

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